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Osteoporosis affects over 200 million people globally, with an estimated 1 in 2 women and 1 in 5 men aged > 50 years expected to experience an osteoporotic fracture. Therefore, there is an urgent need to identify public health strategies to support better bone health in ageing. Several non-modifiable (age, Caucasian ethnicity, female gender and loss of oestrogen) and modifiable (low body weight, physical inactivity, smoking, excessive alcohol) factors are associated with an increased risk of osteoporosis, while nutritional factors are recognised as playing important preventative roles. The essential roles of vitamin D and calcium have been well-documented, but emerging evidence suggests protective roles in bone for folate and related B-vitamins, namely, vitamin B12, vitamin B6 and riboflavin, and/or adverse effects of the related metabolite homocysteine, through a mechanism involving one-carbon metabolism. The overall aim of this thesis was to investigate the potential impacts of these B-vitamins and homocysteine on bone mineral density (BMD) and prevention of osteoporosis. A critical review of the literature was conducted which highlighted that folate-related B-vitamins, and vitamin B12 in particular, may be beneficial to bone health, albeit the evidence to date is predominantly observational and randomised controlled trials (RCTs) are lacking. The findings of this thesis build on the existing literature in this area and provide new evidence from three interrelated studies. The first, an observational study in older adults from the TUDA cohort, showed that atrophic gastritis (a common condition leading to vitamin B12 deficiency) is associated with greater vitamin B12 deficiency, lower BMD and higher risk of osteoporosis. The second, an RCT, was conducted as part of The Optimal Nutrition for Healthier Ageing (OptiAge) study and investigated the effects of low-dose combined B-vitamin intervention for 2 years on nutritional status and bone health in adults ≥ 50 years (n=240). The findings provide the first RCT evidence to show that low-dose B-vitamin intervention can reduce the rate of decline in BMD over time, specifically in older adults with sub-optimal vitamin B12 status. A final study addressed relevant practical considerations to achieve impacts by examining dietary intakes in relation to B-vitamin status, and identified fortified foods as important sources for achieving more optimal B-vitamin biomarkers in older adults, whilst those not regularly consuming fortified food or supplements were at greater risk of B-vitamin deficiency and elevated homocysteine concentrations. In conclusion, the findings of this thesis suggest that the achievement of optimal B-vitamin status in ageing is important for maintaining bone health and osteoporosis prevention, particularly in older adults at risk of low/deficient vitamin B12 status.

Introduction The link between low bone mineral density (BMD) leading to greater fracture risk is well established in the literature; what is not fully understood is the impact of total knee revisions (rTKR) and cone implantation on BMD. This is important due to the increasing fracture risk associated with reductions in BMD. This feasibility study investigated a new type of Stryker cone for rTKR patients, and its impact on BMD utilising different imaging technologies and providing recommendations to be implemented for a full follow up trial. Method A systematic review was conducted to investigate total knee replacement (TKR) and rTKR on BMD results to establish known reported BMD changes after surgery, and to highlight the knee regions investigated. A bovine study was then conducted in order to test the different setup imaging technologies and possible analysis of the cones. Additionally, a novel piece of 3D SHAPER hip software was utilised to investigate bone changes in the hip across three groups (TKR, rTKR, and controls) which could then be compared to the main BMD changes or used as an alternative to the other imaging options. The main study involved recruiting 37 participants all undergoing rTKR to either a cone or non cone group, with all participants undergoing a series of scans via: CT scans (only at six months), DXA and x ray at intervals of pre op, six weeks, three, six and 12 months. Additionally, all participants completed questionnaires on mental health, lower extremity functionality, and quality of life. In addition to BMD investigation, hip and knee alignment was also explored at pre and post op intervals, as well as pixel density changes, both utilising long leg x ray imaging. Results Systematic review results reported 2,431 papers, of which 27 studies were included, across all the studies BMD losses appeared greatest at 12 months. The bovine study helped develop the imaging and analysis required for the main study. The 3D SHAPER ability to be applied to hip DXA imaging showed promise; which was reflected in the control, rTKR and TKR data. The development of different imaging technologies have potential in moving forward into a full trial. Recommendations would include: utilising DXA imaging as the main modality, given its gold standard for BMD changes and its consistency when using a standardised positioning protocol and ROI placement. Long leg x- 3 ray imaging to be used to investigate alignment and pixel density changes, as this imaging is convenient as part of routine follow-up care, although the inclusion of a step wedge within all long leg images would be required to allow pixel density standardisation for investigating in-growth. Finally, the CT imaging could not determine ingrowth in this feasibility study, and therefore should not be utilised in the full study. For the main feasibility study results, 35 participants attended pre--op, 26 attended six weeks and three months, at six months 25 attended, and 22 at 12 months. Results show rTKR is associated with lower BMD in the tibial and femoral stems, and in the medial tibial condyle, and associated with increases beyond the tibial and femoral stems, in both groups. The main difference is in lateral tibial condyle where there are associated increases in BMD in the cone group, and losses reported in the non--cone group. The questionnaire results show a favourable impact for rTKR, with reductions in depression, anxiety, and increases in functionality post--surgery, with the cone group reporting greater changes, although not statistically significant between groups. Alignment analysis shows little difference between.

Globally, ~17 million women and ~2.1 million children are living with HIV. Sub-Saharan Africa accounts for 70% of HIV-infected (HIV+) persons. Mother-To-Child Transmission of HIV (MTCT) during pregnancy, delivery and breastfeeding, is the main route of HIV infection in children. The World Health Organisation recommends lifelong antiretroviral therapy (ART) for all HIV+ pregnant and breastfeeding mothers to prevent MTCT, and breastfeeding for ≥24 months for optimal child health in resource limited settings (Option B+ strategy). Initiation of ART in HIV+ adults is associated with a 2-6% decrease in areal bone mineral density (aBMD) regardless of ART regimen, but data are limited in pregnant and lactating women. Tenofovir, a preferred first-line drug in Option B+ ART regimen, is associated with 1-2% greater decreases in aBMD. Pregnancy and lactation are associated with physiological changes in maternal bone mineral density, but most evidence shows that this is recovered after cessation of breastfeeding. The hypothesis of this thesis is that ART may accentuate the normal process of bone mobilisation during pregnancy and lactation, leading to bone loss that is not recovered in the mother and/or compromised infant growth and bone mineral accretion. The primary objective of this research was to investigate if HIV+ women experience greater reductions in bone mineral compared to HIV-uninfected (HIV-) counterparts. Two groups of pregnant women, 95 HIV+ on ART (Tenofovir-Lamivudine-Efavirenz, previously ART naïve) and 96 HIV- were followed prospectively in Kampala, Uganda. Data were collected at 36 wks gestation (PG36), 2 (PP2) and 14 wks postpartum (PP14). Dual-energy x-ray absorptiometry was used to measure bone phenotype (aBMD, bone mineral content (BMC), bone area (BA), and size-adjusted BMC (SA-BMC, adjusted for height or length, weight and BA) of the whole body (WB) and lumbar spine (LS) in mother-baby pairs, and total hip (TH) in mothers. The primary outcome was the difference between groups in % change (± SE) in maternal LS aBMD between PP2 and PP14. Secondary outcomes included changes in maternal markers of bone formation (P1NP and BAP) and resorption (CTX), serum 25-hydroxy vitamin D (25(OH)D), parathyroid hormone (PTH), plasma and urine concentrations of creatinine (Cr), calcium (Ca), phosphate (PO4) and magnesium (Mg), urine mineral:creatinine ratios, TmCa/GFR and TMP/GFR, respectively), breastmilk mineral composition (Ca, P, Na, K and Na/K ratio); and infant growth Z-scores and bone mineral. Statistical models were adjusted for potential confounders. Median maternal age was 24.5 (IQR 21.1, 26.9) yrs. Mean gestation was 40.9±1.8 wks and not significantly different between groups. All women were breastfeeding at PP2 and PP14. More HIV+ women reported exclusive breastfeeding (PP2: 82.9% v 58.7%, p=0.0008; PP14: 86.7% v 66.2%, p=0.002). Body weight was 4-5% lower in HIV+ women. By PP14, mean duration of ART was 29.3±5.1 wks, adherence was > 95%, and the median CD4 count was 403 (IQR 290-528) cells/mm3. Maternal aBMD decreased between PP2 and PP14 at all skeletal sites in both groups as expected in lactation. Reductions in LS aBMD were not significantly different between groups (-1.8±0.4% vs -2.5±0.4%, p=0.3). However, HIV+ women had a significantly greater reduction in TH aBMD which persisted after adjustment for body size (-3.7±0.3% vs -2.7±0.3%, p=0.04). Median serum 25(OH)D was 67.4 nmol/L (IQR 54.8, 83.7) at PG36 and 57.6 nmol/L (48.7, 70.1) at PP14 with no significant difference between groups. Changes in 25(OH)D and PTH from PG36 to PP14 were not significantly different between groups (25(OH)D: -13.9±4.1% vs -11.1±3.1%; PTH: +60.0±6.4% vs +57.6±6.4%; both p > 0.05). However, HIV+ women had 33-35% greater plasma PTH concentrations at both PG36 and PP14. Bone formation and resorption markers increased in both groups between PG36 and PP14. HIV+ women had greater increases (CTX: +74.6±5.9% vs +56.2±5.9%; P1NP: +100.3±5.0% vs +72.6±5.0%; BAP: +67.2±3.6% vs +57.1±3.6%, all p < 0.05). They also had a greater decrease in plasma Ca (-6.6±0.5% vs-3.8±0.5%, p≤0.0001) and greater increase in plasma phosphate (+14.4±2.0% vs +7.7±2.0%, p=0.02). Changes in plasma Cr and Mg, TmP/GFR and urine mineral:creatinine ratios were not significantly different between the groups. However, at both PG36 and PP14, HIV+ had significantly lower mean plasma Ca (PG36: -1.0±0.5%; PP14: -4.1±0.6%) and TmP/GFR (PG36: -11.4±3.1%; PP14: -7.2±3.0%) but higher PTH (PG36: +33.0±7.0%; PP14: +35.3±7.6%) compared to HIV- women (all p < 0.05). Mean breastmilk Ca decreased between PP2 and PP14, and the changes were not different between the groups (-19.9±3.0% vs -24.2±3.1%, p=0.3). There were no significant changes in breastmilk phosphorus (P) in both groups, but HIV+ women had significantly higher concentrations (PP2: +9.7±3.8%, p=0.01; PP14:+9.6±3.5 %, p=0.007). Breastmilk P was significantly correlated with maternal plasma [CTX] in a separate ANCOVA model (β = +0.13±0.04% per 1% increase in CTX, p=0.0003). Mean breastmilk Na, K concentrations and Na/K decreased between PP2 and PP14 in both groups. However, HIV+ women had a smaller decrease in breastmilk Na (-44.3±8.9% vs -72.6±9.0%, p=0.03). They also had a trend towards smaller reduction in Na/K ratio (-22.2±9.3% vs -46.6.6±9.5%, p=0.07). Babies born to HIV+ mothers (HIV-exposed infants, HEI) had significantly lower gains in weight +53.0±1.4% vs +57.5±1.4%, p=0.02) compared to HIV-unexposed infants (HUI), and also lower weight-for-age (-0.47±0.16, p=0.003) and length-for-age (-0.53±0.18, p=0.005) Z-scores at PP14. HEI had a slower gain in WB BMC (+51.2±1.9% vs +57.3±1.9%, p=0.02), but the difference was not significant after adjustment for body size (-6.0±3.5% vs -7.6±3.8%, p=0.2); showing that the bone mineral accretion was appropriate for achieved infant size. In contrast, HEI had a greater increase in LS BMC (+29.5±1.7% vs +24.4±1.7%, p=0.03), a difference which remained after size-adjustment (+9.4±5.8% vs +4.3±6.2%, p=0.02). This is the first study to compare changes in maternal aBMD and bone metabolism between HIV+ mothers on Option B+ ART and HIV- counterparts. The results show a greater reduction in TH aBMD in Ugandan HIV+ women on Option-B+ ART compared to HIV- in the first three months of lactation, consistent with their greater increases in bone turnover markers, lower TmP/GFR and plasma phosphate, and higher breastmilk phosphorus concentration. Also, HEI have slower growth and whole body bone mineral accretion compared to HUI. It is important to determine if these changes are temporary or have long-term consequences for the bone health of the mother and child.

Bone drilling is an essential part of many orthopaedic surgical procedures, including those for internal fixation and for attaching prosthetics. Drilling into bone is a fundamental skill that can be both very simple, such as drilling through long bones, or very difficult, such as drilling through the vertebral pedicles where incorrectly drilled holes can result in nerve damage, vascular damage or fractured pedicles. Also large forces experienced during bone drilling may promote crack formation and can result in drill overrun, causing considerable damage to surrounding tissues. Therefore, it is important to understand the effect of bone material quality on the bone drilling forces to select favourable drilling conditions, and improve orthopaedic procedures.

Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD) is a systemic disorder which includes abnormal bone chemistry, vascular or soft tissue calcification, and abnormal bone formation. Many of the parameters of CKD-MBD have been associated with an increased mortality risk in renal patients. There were three main facets to this research project. The first aim of this research was to perform two different studies using the Chronic Renal Insufficiency Standards Implementation Study (CRISIS) data. This prospective epidemiological study is designed to identify factors associated with renal progression and survival in the pre-dialysis CKD population. We have shown that for each 0.323mmol/L (1mg/dL) increase in serum phosphate there was a significant stepwise increased risk of death. (HR1.3 (1.1, 1.5) P=0.01). The association of baseline phenotypic data against vascular stiffness measurements was also investigated. Augmentation index measured at the radial artery was associated with a raised systolic blood pressure but no association with biochemical abnormalities was found.We hypothesised that the phosphate effect on survival was related to the effects within the CKD-MBD spectrum and therefore control of secondary hyperparathyroidism would improve bone and cardiovascular parameters. Therefore for the second part of this research we performed a randomised controlled trial to examine the effects of cinacalcet with standard therapy compared to standard therapy alone on bone and cardiovascular parameters in haemodialysis patients with uncontrolled hyperparathyroidism. The change of biochemical parameters and cardiovascular markers were also further explored in secondary analyses alongside survival data. The primary end point of change in vascular calcification at 52 weeks showed no significant difference between arms. As equivalent control of phosphate and iPTH was achieved in both arms secondary analyses were performed. This showed a significant regression of left ventricular hypertrophy and carotid intima-media thickness associated with phosphate but not iPTH reduction. Patients whose phosphate reduced during the study had a survival advantage when followed for 5 years (HR=10.2 (1.1, 104.5) P=0.049). The third part of this research was to investigate iPTH assay variability. We explored the variation in iPTH assays across the North West and paired this with regional audit data. This study showed that despite there being significant variation among iPTH assays across the region the variation in clinical management was still accounting for some variation in achieving PTH targets.In conclusion, serum phosphate, within the normal laboratory range, is associated with an increased mortality in CKD patients. Haemodialysis patients may have improvement of cardiovascular outcomes with tight control of secondary hyperparathyroidism, by whichever therapeutic means. Intact PTH assays variation may alter our clinical management but variation in practice still affects guideline achievement.

Conversely, AA lost femoral neck BMD over the winter and this was not recovered over the summer, although the increase in width of the femoral neck may have partly compensated BMD loss to maintain strength in bending. The final prospective analysis was conducted in a separate sample of female athletes who were diagnosed with a stress fracture injury. The aim of this analysis was to determine the magnitude and time scale of bone loss following a stress fracture injury and subsequent regain following retaining. A group of 4 stress fracture cases and 3 controls were followed for a period of 6-8 months following a stress fracture injury. BMD and BMC (lumbar spine, femoral neck, and trochanter) and estimations of geometric properties CSA, Z and buckling ratio) were assessed using DXA. The mean difference of bone loss and bone regain was determined by BMD, BMC and geometric parameters from baseline to 6-8 weeks and 6-8 weeks to 6-8 months respectively. No significant bone loss was found in either cases or controls from baseline to 6-8 weeks at any of the bone parameters. A significant difference at the femoral neck was found in the injured leg of the stress fracture cases from 6-8weeks to 6-8months (mean (SE) 1.042(0.102) to 1.070(0.102) g/cm2, p=0.004) with no significant change in the contra-lateral case leg 1.036 (0.102) to 1.054(0.109) g/cm2). No significant bone regain was found in the control subjects (health or injured legs ). Thus athletes do not seem to lose significant BMD during the recovery phase of training when partial weight bearing is required. Subsequent bone regain above the initial baseline value does seem to occur in the injured leg within 8 months following the stress fracture once training is resumed. In conclusion the work within this thesis has not only reinforced previous stress fracture findings, showing that a history of stress fracture is increased in athletes with a history of amenorrhoea, but has identified novel results indicating a lower incidence of stress fracture in female endurance athletes than previously reported. Exercise cognitions have been identified as risk factors for stress fracture history independent of menstrual dysfunction. Furthermore and potentially the most novel finding of this research is the importance for the examination of bone geometric properties in amenorrhoeic athletes. Findings suggest that possible structural adaptations counteract the effects of low BMD and annual losses of BMD during seasonal training in amenorrhoeic endurance athletes. In light of these findings this thesis highlights scope for further longitudinal research in the area of structural adaptation to bone in amenorrhoeic athletes. Keywords: Stress fracture, bone mineral density, bone geometry, endurance athletes, menstrual dysfunction, eating and exercise cognitions.

Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill bit penetration and drill bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. This research demonstrates that bone drilling force data if recorded in-vivo, during the repair of bone fractures, can provide information about the strength/quality of the bone. Drilling force does not give a direct measure of bone strength; therefore it has been correlated with the shear strength and screw pullout strength to determine the efficacy in estimating the bone strength. Various synthetic bone material densities and animal bones have been tested to demonstrate the use of drilling force data. A novel automated experimental test rig, which enables drilling tests, screw insertion and screw pullout tests to be carried out in a controlled environment, has been developed. Both drilling and screw pullout tests have been carried out in a single setting of the specimen to reduce the experimental errors and increase repeatability of the results. A significantly high value of correlation (r² > 0.99) between drilling force & shear strength and also between drilling force & normalised screw pullout strength in synthetic bone material was found. Furthermore, a high value of correlation (r² = 0.958 for pig bones and r² = 0.901 for lamb bones) between maximum drilling force & normalised screw pullout strength was also found. The result shows that drilling data can be used to predict material strength. Bone screws are extensively used during the internal fixation of fractured bones. The amount of screw been tightened is one of the main factor which affects the bone-screw fixation quality. Over tightening of screw can result into the loss of bone-screw fixation strength, whereas under tightening can result in the screw loosening. Therefore, optimum tightening of the screw is important to achieve the maximum bone-screw fixation strength. At present, optimum tightening of the screw is entirely dependent upon the skill and judgment of the surgeon, which is predominantly based on the feel of the screw tightening torque. Various studies have been reported in the literature to develop an algorithm to set an optimum tightening torque value to be used in surgery. A method which is based on the use of rotation angle of the screw while tightening, rather than using screw insertion/tightening torque, to optimise the bone-screw fixation strength is proposed in this research. The effectiveness of the proposed method has been successfully demonstrated on the synthetic bone material using the designed test rig. The optimum angle for the tested screw was found to be 120° which is equivalent to 33% of the screw pitch.

Thalassaemia and sickle cell disease (SCD) are the most widely distributed blood genetic disorders that occur at a high frequency in some populations including the Mediterranean region, parts of the Middle East, South East Asia and the Indian subcontinent. It is estimated that thalassaemia major affects 100,000 newborn every year world-wide. The high incidence of these chronic haemolytic diseases in developing countries poses a high load on the national economy because of the expensive treatment protocols and the considerably high morbidity rates of these patients. Repeated blood transfusion to keep haemoglobin above an acceptable level requires well-equipped blood banks with expensive facilities to screen, store and manipulate blood and blood products. Iron chelation therapy is an essential part of treatment to avoid or delay the deleterious effects of iron overload on different organs including the liver, heart, pancreas and endocrine glands. This inquires injecting deferoxamine subcutaneously for 12 hours daily with a special pump. Both deferoxamine and pumps are expensive and therefore not accessible for all patients. In developing countries, the majority of transfusion-dependent patients with chronic haemolytic anaemia (thalassaemia and SCD) suffer from the consequences of sub-optimal treatment. The mortality rate is still high and usually patients die before the age of 30 years. They also suffer from chronic multi-organ damage including cardiac failure, liver cirrhosis, insulin-dependent diabetes mellitus, growth and pubertal failure and many skeletal abnormalities and fractures. In developed countries the introduction of high transfusion regimes and efficient chelation therapy improved survival rates and prevented cardiac and hepatic damage. However, a majority of thalassaemic patients still have significant growth and pubertal abnormalities, bone disease and multiple endocrine disorders. In Egypt the incidence of thalassaemia major ranges between 0.1 - 0.2% which gives very high patient load on the medical services. In our University of Alexandria Children's Hospital, Alexandria, Egypt. The Haematology clinic has an average of 150 thalassaemic children registered. The same problem is encountered by me in the Royal Hospital, Muscat, Oman, with high prevalence of SCD and thalassaemia and suboptimal treatment. Because of the restricted economic resources, both hospitals adopt a low transfusion therapy (to keep haemoglobin above 9 g/dl) with IM chelation 3 times per week. With this form of sub-optimal treatment we observed that a large number of our thalassaemic children have severe growth and pubertal failure/delay, beside other hepatic, cardiac and skeletal abnormalities. In fact they constitute 40% of patients attending our Endocrinology clinic. This stimulated me to perform an extensive study to survey growth and pubertal development in theses patients (study-1) and investigate the different factors that might affect their growth and pubertal development (studies 4 through 10) a \veU as bone mass density (studies > 1,12). The frequent involvement of the liver in these patients led us to study some hepatic functions and the prevalence of transfusion-associated hepatitis B surface antigenaemia and hepatitis-C virus antibody scropositivity in relation to their linear growth (studies 2,3). We studied the nutritional intake of these patients, their intestinal absorption of D-Xylosc and 48-h stool fat content in relation to their body mass index, subcutaneous 'at thickness and mid-arm circumference (studies 4,5,9). Their defective linear growth urged us to investigate their growth hormone (GH) secretion (spontaneous nocturnal as well as after provocation) and insulin-like growth factor-I (IGF-I) and IGK-binding protein-3 (IGKBl'3) concentrations. Our findings demonstrated high prevalence of defective GH secretion in these children that necessitated imaging of their hypothalamic pituitary area. Imaging studies revealed original data about structural abnormalities in the anterior pituitary gland, different degrees of pituitary atrophy and empty sella and infiltration the gland as well as the mid-brain by hacniosidrin in thalassaemic children, the mechanism of these findings was explained (studies 4-6,10). Because of their slow growth, the presence of abnormal GH/IGF-I/BP3 axis, and structural abnormalities of the pituitary gland, the next step dealt with the response of IGF-I to exogenous GH and the clinical response of their linear growth to GH therapy for a year or more (studies 4,9). Based on the fact that these patients have high prevalence of bone pains and osteoporosis during late childhood and have high risk of spontaneous fracture thereafter, we measured their bone mass density to investigate the relation between the former and the degree of iron load, growth parameters, and different anabolic hormone concentrations in these patients (studies 11,12).

Osteoporosis is a major phenomenon, impacting a large proportion of the population of the United States. Effective prevention and mitigation strategies for this condition and its related complications are necessary to promote health and well-being for the aging population. Current pharmacologic agents used to combat osteoporosis bring the risk of adverse effects, resulting in poor patient adherence. Nonpharmacologic methodologies, specifically weight-bearing exercise, targeted nutrition, and whole-body vibration, have proven to be successful in increasing bone mineral density and mitigating the risk of osteoporosis and its related complications. Implementing these methodologies results in increasing bone mineral density, strength, and well-being.

Musculoskeletal injuries account for the majority of career-ending health concerns in Thoroughbred racehorses. A small but very serious subset of these can be life-threatening and usually involve fractures of the bones in the lower limb that occur during high-speed exercise or racing competitions. Understanding the etiopathogenesis of lower forelimb bone fractures leading to catastrophic musculoskeletal injuries (CMI) is the highest safety and welfare priority in horse racing. This thesis conducted two studies utilizing computed tomography (CT) images of Thoroughbred lower limbs. The first examined bone lesion annotations in 134 horses (268 forelimbs) across 105 anatomical sites to assess the concordance of lesion profiles. A series of pairwise comparisons were conducted utilizing a Hamming similarity metric to test the hypothesis that contralateral forelimbs exhibit high bone lesion concordance. The results strongly supported the hypothesis. Contralateral forelimbs displayed the highest level of lesion concordance in 101 instances, accounting for 37.69% of forelimbs within the population. While over half of the contralateral forelimbs (63.43% or 170 forelimbs) ranked within the top five positions based on Hamming similarity score rank. The second study assessed the degree of bone mineral density (BMD) adaptation of bones in the metacarpophalangeal (MCP) joint in response to the predictor variables age, gender, body weight, skeletal health, and recorded race starts. Samples used were categorized into four skeletal health groups corresponding to race training experience and primary cause of death. The hypothesis tested was that bones within the MCP joint of Thoroughbred racehorses exhibit concordant BMD changes in response to physiological modeling and remodeling. The results supported the hypothesis, but also identified interesting differences between bones that may be associated with disproportionate patterns of load and force distribution. Taken together, these studies contribute to the continuing efforts aimed at improving the safety and welfare of Thoroughbred racehorses and their riders.

Type 2 diabetes (T2D) is an increasingly prevalent condition that is associated with numerous complications, including poor bone health. However, the phenotype of skeletal fragility in T2D is not well defined: fracture risk in T2D is not uniform and the independent risk factors for fracture in T2D are unclear. Since fragility fractures result in significant morbidity and mortality, fractures in T2D could represent a substantial health burden in this already vulnerable group. Currently a key limitation in understanding skeletal fragility in T2D is the relative separation of bone and diabetes. There are no prospective studies in which both detailed bone and diabetes-related characteristics have been collected simultaneously. Therefore, characterising the unique effects of a clinically variable condition such as T2D, and, identifying the independent metabolic contributors to skeletal fragility, have not been possible. This thesis comprises three studies that explore the bone-metabolic relationship by examining novel bone-related outcomes in two unique cohorts with extensive patient metabolic characterisation. First, the risk of fracture and post-fracture mortality following any fragility fracture in T2D was determined in the Dubbo Osteoporosis Epidemiology Study (DOES). Despite higher bone mineral density (BMD), there was no difference in fracture risk in T2D. However, the combination of T2D and any fracture conferred excess mortality (2.6-fold). Mortality was increased following fractures at all skeletal sites, including non-hip non-vertebral fractures, which constituted half of the fractures. T2D-related characteristics associated with increased post-fracture mortality were T2D duration >5 years and possibly insulin treatment. Second, in a post hoc analysis of the randomised controlled trial Fenofibrate Intervention and Event Lowering in Diabetes (FIELD), incident fracture at any site was associated with baseline vascular complications (macrovascular disease in men, peripheral neuropathy in women), HDL-cholesterol in men, and insulin use in both sexes. Risk factors varied according to the skeletal site of fracture, suggesting differing underlying pathophysiological contributors. Third, in a cross-sectional analysis of a subset of DOES, I dissected the relative contributions of obesity, body composition, insulin resistance, and T2D on comprehensive bone parameters. T2D was associated with low bone turnover markers, independent of body weight and visceral adipose tissue (VAT). BMD and advanced hip analysis were predominantly associated with age and body size, however VAT was also independently associated with impaired bone geometry. This thesis illustrates the heterogeneity of diabetic osteopathy. Metabolic dysfunction is associated with, and may contribute to, poorer skeletal outcomes. Using a bone-centric approach in assessing skeletal health in T2D reveals gaps relating to patient management. Instead, a T2D-centric approach highlights the role of metabolic factors in risk assessment and clarifies potential underlying pathophysiological mechanisms. Unifying the bone and metabolic phenotypes is critical to refining skeletal assessment in T2D and directing interventional studies that may optimise the clinical management of these patients and reduce the overall burden of diabetic osteopathy.

El tabaco es una de las principales causas evitables de muerte y discapacidad [1]. Se estima que causa una media de 51.870 muertes al año en España [2], con una evolución diferente en los hombres en los que tiende a disminuir, frente a las mujeres donde han aumentado. A pesar de una aparente disminución de la prevalencia del tabaquismo, el porcentaje de personas que consume productos derivados del tabaco continúa aumentando con el crecimiento de la población. Se estima que existen unos 967 millones de fumadores activos en todo el mundo [3], situándose aproximadamente unos 42,1 millones de ellos en Norte América [4]. La prevalencia de consumo de tabaco en España es aún elevada, con un 24,4% de fumadores actuales (diarios y ocasionales) de entre 15 y más años (28,2% en hombres y 20,8% en mujeres) según los últimos datos de la encuesta nacional de salud de España de 2017 (ENSE2017) [5].

The purpose of this study was to quantify and compare the degree of bone erosion of middle ear bone structures in response to middle ear cholesteatoma (CHST); and to measure the recovery of bone integrity post oncolytic herpes simplex virus (oHSV) treatment for CHST in the gerbil model. Data was collected from previously acquired micro-computed tomography (CT) scans of 12 total Mongolian gerbils (Samy et al., 2019a). 10 experimental gerbils (n = 20 ears) received Pseudomonas aeruginosa (PA) inoculations plus double ligation of the external auditory canal to expedite CHST growth. Two weeks post PA inoculation, the 10 gerbils (n = 20 ears) received intrabullar injections of oHSV. Of those animals, five (n = 10 ears) received a second intrabullar oHSV injection. And of those animals, two (n = 4 ears) received a third injection. All oHSV treatments were administered biweekly. Micro-CT scans were obtained two weeks post CHST induction and 2-4 weeks after each oHSV treatment. Micro-CT scans of two unoperated gerbils were included as controls. Micro-CT analyses included two regions of interest (ROIs): a cross section of the auditory bulla, and the ossicular chain. ROIs were manually traced and filtered (based on Hounsfield units, HU) using a voxel labeling tool from Siemens Inveon Research Workplace software. Micro-CT analyses included volumetric measurements of the ossicle ROIs (measured in mm3), the perimeter of the auditory bulla ROIs (measured in mm), and bone mineral density (BMD) estimations of the ossicle and bulla ROIs (measured as the average HU-per-voxel).At two weeks post CHST induction, the mean bullar perimeter of experimental animals was significantly lower than the control animals (p = 0.044), indicating bone erosion of the auditory bulla. There were no significant differences in volume and estimated BMD for any of the ossicle ROIs. When treated with oHSV, animals exhibited a significant increase in estimated BMD of the bulla after the first two injections (p < 0.001). Post third oHSV injection, the bullar BMD was significantly higher compared to the control group (p < 0.001) and the bullar perimeter significantly increased from pre oHSV treatment to post third oHSV injection (p = 0.017) with no statistically significant difference in mean perimeter between animals that received three oHSV injections and the control group. Of the three ossicle bones (malleus, incus, and stapes), the malleus was the only structure that significantly decreased in volume after each oHSV injection (p = 0.021), indicating that bone erosion occurs at this site even during oHSV treatment. However, a significant increase in estimated BMD of the malleus was noted from pre oHSV treatment to post third oHSV injection (p < 0.004). The ossicular chain ROIs were refiltered at HU ranges of 3000-8000 HU, 4000-8000 HU, and 5000-8000 HU to account for variations in BMD across different bone regions. When refiltered at 5000-8000 HU, the mean volume of the ossicular chain ROIs significantly increased from the second oHSV treatment to the third oHSV treatment (p < 0.003). Findings suggest that the gerbil auditory bulla is more prone than the ossicular chain to resorption two weeks after CHST induction. Bone erosion recovery was indicated at the level of the auditory bulla following oHSV treatment, however, there was a significant increase in estimated BMD post treatment compared to controls. The malleus exhibited a significant reduction in volume while the estimated BMD increased throughout oHSV treatment. Further investigation detected a significant increase in volume within the densest region of the bone. This suggests that different regions of the ossicular chain are responding differently to oHSV. These results support further investigation to determine if changes in bullar density are permanent, and if recovery of integrity of the ossicular chain requires a longer time course.

Sports participation is associated with adaptations in bone strength that reflects positively on bone mineral density (BMD). Although this participation has been positively associated with increased BMD, there is substantial heterogeneity in the osteogenic response from the various types of physical loading (e.g., gravitational loading, muscle loading) that are within sports. Therefore, the purpose of the current investigation is to determine the most influential predictive factors of BMD using anthropometric and performance-based assessments, as well as to compare BMD values between sports containing components of gravitational loading (GL) and muscle loading (ML) in Division-I female collegiate athletes. The results of this study suggest that the influence of various anthropometric and performance-based factors on BMD in female collegiate athletes, depends on the type mechanical loading that is performed during sport participation. While weight was reported to be the most influential factor for BMD in GL sports, extracellular fluid was the most influential factor for ML sports.

Background: In 2014, the International Olympic Committee (IOC) introduced the term “Relative Energy Deficiency in Sport” (RED-S), which expands on the prior Female Athlete Triad. RED-S is a more comprehensive term that emphasizes additional impaired physiological functions due to low energy availability (EA). Health consequences associated with RED-S can negatively affect sports performance in young adult female distance runners.Objective: Describe the characteristics of RED-S; EA, menstrual/bone health, body composition, and nutritional, hematological, and psychological factors in young adult competitive female distance runners.Methods: The cross-sectional study recruited 11 young adult (22.8 +/-2.0 years) female distance runners. Measures were collected via laboratory visit; anthropometric measurement, dual x-ray absorptiometry (iDXA), and blood analysis, and questionnaires; injury history, menstrual health questions, modified activity questionnaire (MAQ), eating disorder examination questionnaire (EDE-Q), perceived stress scale (PSS), and VioScreen food frequency questionnaire (FFQ). Results: EA: Mean EA was 33.8 +/- 10.8kcal/kg FFM/day. Two participants had optimal (EA >45), five participants had adequate (EA 30-45), and four participants had low EA (EA < 30). Menstrual health: Eight participants were eumenorrheic (>9 menses/yr) and three participants were oligomenorrheic (6-9 menses/yr). Bone health according to lowest site: Five participants had optimal (z-score >-1.0), five participants had low (z-score -1.0 to -2.0), and one participant had osteoporosis (z-score

Bone is often regarded as a mostly inorganic tissue. Osteoporosis, a skeletal metabolic disorder characterized by increased bone fragility and fracture risk, is currently diagnosed by Dual X-Ray Absorptiometry (DXA) scan. However, DXA scanning is a poor predictor of fracture risk and bone quality, as it only assesses the mineral content of bone. Recent research increasingly suggests that other nonmineral parameters contribute to bone strength, such as size, geometry, and organic collagen. As a result, it is imperative to find a better diagnostic tool that more accurately encapsulates these other factors. One potential solution is Cortical Bone Mechanics Technology (CBMT), a novel technology being developed at Ohio University that uses noninvasive, radiation-free three point mechanical loading test to assess bone flexural rigidity (EI). Because CBMT is a mechanical test, it is believed to better detect changes in nonmineral factors. To assess this, compromising of the organic collagen matrix was induced using potassium hydroxide (KOH), which does not affect bone mineral. Paired cadaveric human forearms (n=16) were treated with either saline (n=8) or KOH (n=8). No statistically significant difference was present between the right and left T-scores of excised ulnas prior to chemical incubation (p= 0.40). No statistically significant difference between the KOH and saline cohorts prior to chemical incubation (p=0.27). Arms were assessed with DXA and CBMT both before and after treatment. Saline immersion did not reduce EIQMT (+0.9±1.2%, p= 0.76) or EICBMT (-0.6±2.3%, p=0.40). By contrast, KOH immersion reduced both EIQMT (-27.2±3.2%, p

Currently, there is no way to measure bone strength in living people. In the absence of such a measure, areal bone mineral density (aBMD) by dual energy x-ray absorptiometry (DXA) has become the standard used to assess bone health. DXA does not measure bone mechanics and aBMD does not predict fracture risk well. Cortical Bone Mechanics Technology (CBMT) is a device capable of measuring ulna bending stiffness in living people and has been shown to predict bone strength. Previously, Wynnyckyj and colleagues found 14 days of 1 M potassium hydroxide (KOH) treatment on the endocortical surface of emu tibias reduced elastic modulus values by 17% through bone collagen degradation. DXA measurements of aBMD did not change after KOH treatment. The purpose of this study was to determine the accuracy of CBMT in measuring excised human ulna flexural rigidity (EI) and estimating cortical bending strength with potassium hydroxide (KOH) induced collagen degradation by comparing measurements made by quasi-static mechanical testing (QMT). DXA measurements of the ulna were made to test DXA’s ability to detect changes in the bone. An additional goal of this study was to compare periosteal (immersion) KOH treatment to the endosteal (endocortical) treatment used in the study performed by Wynnyckyj and colleagues. A randomized experimental design was used in which eight pairs of ulna bones excised from cadaveric human arms were immersed in 1 M potassium hydroxide (KOH) solution or a 0.9% calcium-buffered saline solution. For each pair of arms, the saline solution served as the control for the KOH solution. DXA measurement of ulna area (cm2), BMC (g) and aBMD (g/cm2) at the 1/3 region of the ulna and CBMT and QMT measurement of ulna EI (Nm2) were made before and after immersion. QMT measurements of bone bending strength are destructive and could only be made after immersion. The maximum moment (Mmax, Nm) was used to indicate bone strength. Effect of KOH on bone strength was detected by comparison to the contralateral ulna immersed in saline.The average percent change in nondestructive EI of the eight saline immersed specimens measured with QMT displayed no decrease in EI (p=0.77) but EI declined by 27.2 ± 3.2% after 39 hours of immersion in 1 M KOH (p

Information regarding bone health and body composition can provide insight into the risk factors for fracture and other bone related disease. Peak bone development is thought to be achieved in the young adult years of an individual’s life and can be indicative of risk of osteoporosis later in life. This study aims to explore the relationship between bone mineral density (BMD) and body composition measurements from a college aged non-student athlete population (n = 61) to that of a student-athlete population (n = 39). Furthermore, sex specific differences between and within the subgroups were evaluated. No statistical difference was found for BMD, weight, lean mass, and bone mineral content between subgroups. However, sex-specific differences were present for all variables of interest. Pearson’s correlation coefficient results indicate that there was a moderate to strong relationship between BMD and lean mass for all groups.

Purpose: The aim of this study was to analyze the relationship between anthropometrics, sport-specific training history, and bone mineral density (BMD) in female Olympic weightlifters (OL) (n=8), power lifters (PL) (n=8), soccer players (SP) (n=10), and recreationally active participants (RA) (n=11). Methods: Certain anthropometrics and BMD in the femoral neck, lumbar, and total body were measured by dual-energy x-ray absorptiometry and other standard methods. BMD measurements, anthropometrics, and training history were compared using one-way ANOVA. Significance for ANOVA was set at p ˂ 0.05. Results: OL had significantly denser L2 (p = 0.013), L3 (p = 0.006), L4 (p = 0.002), and L1-L4 (p = 0.004) vertebrae than RA. PL also showed a significantly higher L4 BMD than RA (p = 0.025). All three athletic groups were significantly denser than RA (p ˂ 0.01) in total body BMD. OL were also shown to be significantly denser than PL (p = 0.021) in total body BMD, but there was no significant difference between OL and SP. At the femoral neck, both OL (p = 0.03) and SP (p ˂ 0.001) were shown to have a significantly higher BMD than RA. Conclusion: All three sports will improve total body BMD. However, Olympic weightlifting is clearly superior to power lifting in building BMD in the lumbar spine, femoral neck, and the total body. Power lifting also provides limited significant improvement in the lumbar spine as well. Soccer also has great benefits for the femoral neck, but not the lumbar spine.

Background: Children with congenital adrenal hyperplasia (CAH) are exposed to fluctuating cortisol and androgen levels. The effects these hormonal states have on bone mineral density (BMD) and body composition are not well studied. Objective: Compare BMD and body composition in children with CAH vs. healthy age-, sex-, and BMI-matched controls. Methods: Forty-two cases with CAH and 101 controls underwent a dual-energy X-ray absorptiometry scan. Bone age Z-scores were used as a surrogate for long-term androgen exposure in cases. Results: Children with CAH had lower BMD Z-scores than controls. In CAH cases, BMD Z-scores were positively correlated with bone age Z-scores. Body composition markers did not differ between children with CAH and controls. Conclusion: Lower BMD was observed in CAH cases, but no differences in body composition were identified. Among CAH cases, increased chronic androgen exposure, as measured by bone age Z-scores, was associated with higher BMD.

Osteoporosis is a silent disease as patients are often unaware of their condition until a fracture occurs. Thus, early detection and identification of at-risk individuals are essential. Although bone mineral density (BMD) testing is the “gold standard” for fracture risk assessment, a substantial proportion of fracture cases remain unexplained by BMD. Quantitative ultrasound (QUS) with its potential to measure both bone density and structure may offer additional information in identifying at-risk individuals. Meanwhile, both osteoarthritis (OA) and obesity are associated with high BMD, but their relationships with fracture risk are still unclear. Therefore, the primary aims of this thesis are: (1) to evaluate the contribution of QUS to fracture risk assessment, with particular emphasis on individuals without low BMD; and (2) to determine the association between OA or body mass index (BMI) and fracture risk in relation to BMD. Using prospective data from the Dubbo Osteoporosis Epidemiology Study (DOES), it was found that calcaneal QUS was significantly associated with fracture risk, independent of BMD in women with or without osteoporotic BMD. More importantly, a combination of broadband ultrasound attenuation (BUA) and BMD can improve the prediction of fracture risk by 7.3% in women. However, the fracture predictability of QUS seems to be device-specific, as QUS measured by a multisite device was not predictive of fracture risk in both men and women. Although higher BMI was found to be associated with lower fracture risk, its protective effect against fracture was largely mediated by BMD. The overall mediated effect estimates were -0.048 (95% CI, -0.059 to -0.036; p

Background: The female athlete triad is defined as “a spectrum of abnormalities in energyavailability, menstrual function, and bone mineral density”. This spectrum of abnormalitiesrefers to a range of severity from normal to varying degrees of pathology for each component ofthe triad. The female athlete triad has been studied extensively in adult women, but few studieshave evaluated the triad and its associated conditions, namely suppressed resting metabolic rate,among adolescent female athletes.Objectives: To describe the components of the female athlete triad and resting metabolic rateamong a cohort of middle-to-upper class adolescent female athletes.Methods: A convenience sample of adolescent female participants ages 14-18 was recruited froma middle-to-upper class suburban high school in Ohio. Each participant attended one, individualone-hour laboratory visit. During this visit, bone mineral density measurements were conductedfor total body, femoral neck, lumbar spine, and ultra-distal radius using a General Electric LunariDXA. Resting metabolic rate was estimated using a Korr Medical Technologies ReeVue IndirectCalorimeter. Prior to the laboratory visit, each participant received a VioScreen Food FrequencyQuestionnaire® to estimate caloric energy intake and a compendium of questionnaires generatedusing the Research Electronic Data Capture (REDCap) application to self-report and estimatephysical activity and menstrual function.2 Energy availability was estimated using estimates ofenergy intake and exercise energy expenditure derived from the questionnaires, as well asmeasured kilograms of lean body mass. Participants were categorized into one of two menstrualfunction categories: dysmenorrheic and eumenorrheic. Bone mineral density z-scores werereported for total body less head (TBLH) and lumbar spine. The Cunningham equation and theHarris-Benedict equation were used to produce two estimated RMR values for each participant.These estimated rates were compared to the measured RMR to determine if there were significantdifferences between predicted and measured RMR among this sample of adolescent femaleathletes. Descriptive statistical analysis was performed to describe the components of the femaleathlete triad and resting metabolic rate. Spearman’s correlation was used to describe the potentialcorrelations between variables; correlations were significant if p=0.05. The Mann-Whitney U testwas used to assess differences between menstrual function categories. The Related-SamplesWilcoxon Signed Rank Test was used to compare median differences between RMR measured byindirect calorimetry and RMR predicted from the Cunningham equation and the Harris-Benedictequation individually.Results: Nineteen participants were recruited; 17 participants provided complete data sets. Nineparticipants (56.3%) exhibited low energy availability (less than 30 kcal/kg LBM/day), 2participants (14.3%) exhibited menstrual dysfunction, and 4 participants (21.1%) exhibited lowlumbar spine BMD z-scores. One participant exhibited all three components of the female athletetriad. Based on the 2007 diagnostic criteria, 11 participants exhibited one or more pathologic triadcomponents and would therefore be diagnosed with the female athlete triad. Data analysisrevealed a significant correlation between TBLH BMD z-score and lumbar spine BMD z-score.Both total mass and lean body mass were significantly correlated with TBLH z-score and lumbarspine z-score. A significant correlation was observed between lumbar spine BMD z-score andosteogenic potential (Ost score). Dysmenorrheic participants trended toward lower energyavailability than eumenorrheic participants, however this trend was not significant. A significantcorrelation was observed between energy availability and daily energy intake. Though nosignificant correlations were observed between RMR and other variables, the median ofdifferences between measured RMR and HB-predicted RMR was significantly different. Thisdifference was not observed between measured RMR and Cunningham-predicted RMR.Conclusion: Each component of the female athlete triad was present among this cohort ofadolescent female athletes. Additional research is needed to more thoroughly describe theprevalence and severity of the components of the female athlete triad and resting metabolic rate inthe adolescent population. This additional research will aid in the development of educationalcurricula and protocols to address screening, prevention, and treatment of the triad. Theseresources and tools are necessary to protect the present and future health of the adolescent femaleathlete.

Bone mineral density (BMD) is an important aspect of bone health in endurance runners. Musculoskeletal overuse injuries to the bone, such as stress reactions and stress fractures, are of major concern to endurance runners and coaches because of the debilitating nature they have on training and performance. It is possible that a greater understanding of BMD in these athletes can lead to a reduction in stress injuries to bone. The purpose of this study was to determine if BMD in certain anatomical regions, especially that of the lower appendicular skeleton, changed over the course of an indoor track season and if there was any significant difference between middle distance and distance runners. Participants were scanned for BMD estimates before the start of the indoor track and field season and after the indoor track and field season. On both testing days they were asked to complete a questionnaire through which they self-identified into either a middle distance or long distance group and also through which they provided any recent history of musculoskeletal injuries. Among the BMD measure comparisons, it was found that a statistically significant difference (p < 0.05) existed between middle distance and long distance runners when comparing pre-season to post-season changes of BMD in the legs. Additionally, the difference between pre-season and post-season values of total body BMD for male middle distance runners (p < 0.01) and the difference between pre-season and post-season values of leg BMD for male middle distance runners (p < 0.05) were both significant. Finally, statistically significant differences were found (p < 0.05) between the pre-season and post-season total body BMD values for female middle distance runners and statistically significant differences were found (p < 0.05) between the pre-season and post-season pelvis BMD values for female long distance runners. These statistical findings may not translate directly into practical application, but given the nature of the potentially precarious balance between the microstrain placed on bone and bone remodeling during a following endurance running, these results should at least be scrutinized closely.

Osteopenia and/or Osteoporosis (OOS) is becoming an increasingly prevalent chronic disease among Beta Thalassemia Major (BTM) patients, especially now that life expectancy in these patients has considerably improved through regular blood transfusions and iron chelation therapy. With several, complex genetic and acquired factors involved in its pathogenesis, coupled with the heterogeneity in the clinical response of BTM patients to different pharmacological agents, OOS has proven to be particularly difficult to treat. The great majority of treatment options currently available are not curative, but instead are aimed towards managing the symptoms and progression of the disease in patients. General preventative measures, such as iron chelation therapy and hormonal replacement therapy (HRT), are instrumental aspects of the treatment plan; however, the incredible complexity of OOS necessitates an individualized, multidisciplinary approach to management, with a principal therapy that is safe and effective in patients, and that is accompanied by these other supportive measures. This review, through a comprehensive analysis of current literature, includes data from randomized, placebo-controlled trials, double blind and observational clinical studies, and suggests optimal therapeutic interventions for first-line management of OOS. It also addresses treatment options for BTM patients in whom resistance to the recommended first-line therapy develops, or who display secondary endocrine conditions contributing to OOS. In addition to providing a current synopsis of OOS management and the potential of emerging treatment options, this analysis highlights some of the limitations of traditional therapies. In this way, the paper effectively illustrates the current status of TM-induced OOS; it describes what is or isn’t working, as well as underscores the diagnostic and therapeutic challenges continually faced by patients, researchers and clinicians.

Background: Trabecular bone score (TBS), which has been proposed to be used in complementary with bone mineral density (BMD) to improve the assessment of fracture risk, is negatively associated with body mass index (BMI). The effect of soft tissue, which is expected to be thicker in subjects with high BMI, on TBS was studied using three scan types: Hologic with fast array mode (Hfa), Hologic with high definition mode (Hhd), and GE-Lunar iDXA. Methods: A spine phantom provided by Hologic for routine quality control procedure was scanned using three scan types: Hfa, Hhd, and iDXA. The phantom was scanned with an overlying soft tissue equivalent material (bolus used in radiotherapy) of 0 (without), 1, 2.5, 3.5, 5 and 7.5 cm thick. For each setting, 30 acquisitions were performed in the same way as for the quality control procedure. TBS was calculated using TBS iNsight® software version 2.1 on the same regions of interest as those used for lumbar spine BMD. Results: Mean ± SD TBS of the phantom (without overlying soft tissue) were 1.379 ± 0.018, 1.430 ± 0.009, and 1.423 ± 0.005 using Hfa, Hhd, and iDXA, respectively. A one-way repeated measures ANOVA showed that there were statistically differences in TBS due to different thicknesses of soft tissue equivalent materials for all three scan types (p < 0.001). A Tukey post-hoc test revealed that the decrease in TBS was statistically significant (p < 0.001) when the soft tissue thickness was 1 cm (−0.0246 ± 0.0044, −0.0319 ± 0.0036, and −0.0552 ± 0.0015 for Hfa, Hhd, and iDXA, respectively). Although to a lesser degree, the effects were also statistically significant for BMD (p < 0.05): an increase for Hfa and Hhd but a decrease for iDXA. However, these changes did not exceed the least significant change (LSC) derived from patients. Conclusions: Increased soft tissue thickness results in lower TBS value. Although BMD is also affected, it is unlikely to pose a clinical problem because the change is unlikely to exceed the patient-derived LSC.

There is no quantitative method for evaluating infant bone quality that is non-invasive, portable, brief in scan duration, and does not use ionizing radiation. This study investigates the relationship between components of infant bone quality and a measure of quantitative ultrasound (QUS), speed of sound (SOS), to provide insight into the validity of QUS as a diagnostic tool for evaluating infant bone quality. The study sample was comprised of 78 infants between the age of 30 weeks estimated gestational age and 12 postnatal months receiving an autopsy at the Harris County Institute of Forensic Sciences and Texas Children’s Hospital. Bone SOS measurements, costochondral rib and iliac crest samples, and radiographs of the forearm and leg were prospectively collected over a 9-month period. Demographic information, medical history, autopsy findings, and investigator reports were collected and used to identify chronic illness. Qualitative radiographic evaluation, bone mineral density (BMD), and tibial measurements were obtained from radiographs. Results indicated that SOS measures aspects of bone quality related to bone macrostructure. Prematurity and chronic illness were significantly associated in the current study sample and their detrimental effects could not be separated. Prematurity and, possibly, chronic illness significantly influenced SOS through their adverse effects on growth and bone health. BMD was not significantly associated with tibial or body size measurements, but this may have been due to the small area of bone used to estimate BMD. Although SOS and BMD were not significantly correlated, both showed a postnatal decline and subsequent increase at greater ages. Chronically ill infants had significantly lower BMD and greater qualitative radiographic evaluation scores than infants without chronic illness. Assessing bone quality is complex due to the multitude of factors which compose it. QUS remains a highly promising technology for evaluating infant bone quality, but it cannot be definitively concluded that QUS is a valid technique for evaluating infant bone quality based on this research alone. Research comparing SOS to finer-grained measurements of aspects of bone quality are necessary before the validity of QUS as a diagnostic tool for evaluating infant bone quality and strength can be determined.

Cystic fibrosis (CF) is one of the most common genetic disorders in the United States. As there have been advancements in medical care, individuals with CF are living longer. There has been an increase in the comorbidities associated with CF because individuals have increased lifespan. Particularly cystic fibrosis related diabetes (CFRD) is one of the most common comorbidities, and it is associated with a decline in clinical status. Low vitamin D levels are a common occurrence in the CF population due to fat malabsorption. Non-CF populations with type 1 or type 2 diabetes mellitus have been found to have an association with low vitamin D levels. Vitamin D has not been well studied in association to CFRD. A retrospective chart review was conducted to determine the relationships between vitamin D status and glucose tolerance, vitamin D status and other health indicators, and vitamin D status and bone mineral density. Subjects that were included demonstrated diagnosis of classic CF (pancreatic insufficiency, sweat chloride >60 mmol/L, two disease causing gene mutations), age 10 or older in 2009, and had complete data for the year 2011. Results showed statistically significant positive correlations between glucose tolerance and vitamin D status, BMI and percent-predicted FEV1, glucose tolerance and bone mineral density, and vitamin D status and bone mineral density. Results also showed mean vitamin D levels in the insufficient range in the three years leading to CFRD diagnosis. The findings indicate that low vitamin D may be a risk factor for the development of CFRD, and insufficient vitamin D levels may have a greater impact on health than was previously believed. CF care providers should advocate for individuals with CF to have adequate vitamin D status, as it is associated with better health outcomes.

The Female Athlete Triad, consisting of the interrelated conditions of low energy availability, leading to menstrual disturbances and low bone mineral density, is commonly diagnosed amongst excessively exercising women. The American College of Sports Medicine emphasizes that the underlying factor of the Triad is a discrepancy between dietary energy intake and the energy requirements needed to support high levels of physical activity in addition to other homeostatic and physiological bodily processes. Although low energy availability is largely recognized as a causative factor for amenorrhea and low bone density, no studies to date have examined specific macro- and micro-nutrient intake relating to bone mineral density in the female athlete population. The hypothesis to be tested was that a difference in the intake of specific nutrients between athletes with menstrual disturbances (amenorrheic) and regularly menstruating (eumenorrheic) athletes contributes to low bone mineral density in female athletes exhibiting symptoms of the Triad. Methods: 4-day food records were collected from 118 females, ages 14-23 years, who exhibited weight within the normal range. 68 participants were amenorrheic athletes (AA), 24 participants were eumenorrheic athletes (EUM), and 26 participants were non-exercising females within the same age group (non-athletes: NA). Serum levels of vitamin D, phosphorus, calcium, and estradiol were also collected. Results: In contrast to previous studies, there was no difference in energy availability between the AA, EUM, and NA groups. The groups did differ in their intake of several macro-and micro-nutrients, and many of these nutrients correlated significantly with lumbar spine BMD. In a multivariate model that included vegetable and total proteins, soluble, insoluble and total dietary fiber, pectins, phytic acid, natural folate, calcium intake, vitamin D intake, serum vitamin D levels, and % calories from saturated fatty acids (SFA), only dietary fiber remained negatively associated and % calories from SFA positively associated with lumbar spine BMD. Conclusions: Dietary fiber has a significant inverse association and % calories from SFA a positive association with lumbar spine BMD, even after controlling for other nutrient intake and serum levels and intake of Vitamin D and calcium. Therefore, fiber and saturated fat may exert effects unrelated to vitamin D status and overall energy availability to impact bone density. Nutrition guidelines for female athlete triad patients need to be reassessed.

Background: Daily nutrient/energy intakes are typically evaluated as a total 24-hour intake rather than as the amounts consumed per eating opportunity. Evidence suggests that smaller, frequent meals containing persistent levels of energy and protein may be more beneficial for achieving a lower body fat and higher fat-free mass than equal intakes consumed in larger and less frequent amounts. This may be due to a better-maintained energy balance (EB) that is achieved with smaller and more frequent intakes. Objective: The objective of this study was to determine the relationship between hourly EB and protein intake with body composition. Methods: Using a software program that provides hourly and 24-hour energy and nutrient intakes and hourly energy expenditures, a secondary analysis of previously collected 3-day food diaries was used to examine the relationship between hourly EB and body composition. The food and activity diaries provided information on time of food/beverage consumption and hourly energy expenditure, enabling an hourly analysis of EB. Body composition, including fat mass, fat-free mass, and bone density were examined via dual-energy x-ray absorptiometry. SPSS was used for statistical analysis, and included descriptive statistics, correlational analyses, t-tests, and regression analyses. Results: Existing data from elite female gymnasts (N=40) were assessed using an IRB-approved protocol. Higher protein consumption was significantly associated with lower bone mineral density (BMD) in the gymnasts at the arms (r= -0.535; p< 0.001), legs (r= 0.0523; p= 0.001), trunk(r= -0.517; p=0.001), spine (r= -0.472; p=0.002), and pelvis (r= -0.539; p< 0.001). Other dietary factors assessing energy and protein intakes were not significantly associated with body composition. The assessed gymnasts spent the majority of the day in hourly energy balance deficits exceeding -400 kcal. A t-test comparing subjects with higher (n=22) vs. lower (n=18) fat-free mass (FFM), using the statistical mean as the cut point, found that higher protein intakes were significantly associated with lower FFM (p=.007). Subjects with more hours spent in an EB surplus had significantly higher FFM/kg (p=.008) and lower body fat % (p=.008). Conclusion: These findings suggest that higher protein intakes may compromise BMD, a finding likely exacerbated by the long periods of time spent in EB deficits. More hours in an EB surplus was associated with positive outcomes, including higher FFM/kg and lower body fat percent. These data suggest that higher protein intakes may be consumed by gymnasts with the greatest EB deficits, perhaps as a way of minimizing (unsuccessfully) weight and fat-mass. As virtually all hours of the assessed groups were in an EB deficit, it is possible that consumed protein was used to satisfy energy needs rather than being used anabolically to support or enlarge the muscle mass. Future studies should consider addressing this issue, perhaps by assessing more heterogeneous groups where at least a proportion of the population sustains a reasonably good EB during the assessment period.

Diabetes mellitus is one of the most prevalent and significant metabolic diseases impacting modern human populations. The goal of this research is to explore several analytical methods to better appreciate how diabetes impacts the skeleton, and to determine if this effect can be recognized in postmortem remains. Anthropologists are tasked with elucidating the relationship between nutrition, metabolism, growth, development, and skeletal health. Diabetes represents a crucial point of interface between these factors. Furthermore, as the percentage of diabetics increases in the general population, so will their representation in forensic cases. This study will provide tools for identifying characteristics of diabetes in the postmortem material available to anthropologists. Diabetes is a disease process that can alter the function of many tissues and systems. For these reasons, three analytical approaches were conducted including: blood serum protein analysis using ELISA, bone mineral density (BMD) scans with a dual-energy x-ray absorptiometry (DXA) scanner, and macroscopic osteological analysis. This study was completed employing a sample of 80 known skeletal donations and 20 blood samples from the William M. Bass Donated Skeletal Collection at the University of Tennessee, Knoxville. Results indicated that pro-inflammatory biomarkers may be quantified in postmortem blood samples, and that diabetics showed slightly higher average concentrations of cytokines associated with diabetes and lower concentrations of those related to insulin sensitivity. Bone density analysis revealed that diabetics and non-diabetics significantly differ in BMD, but this relationship varies between the sexes. Female diabetics had consistently denser bones in all measured variables of the lower limb, and one-third of forearm variables. Results based on male data did not display a similar outcome, with little difference observed between male diabetics and non-diabetics. Analysis of skeletal pathologies identified a set of three osteological variables, concentrated in the feet, as having the highest discriminatory potential. An accuracy rate of 83% was achieved in classifying individuals into diabetic versus non-diabetic categories.

Bone loss and fractures are more common in HIV‐infected than HIV-uninfected adults. This thesis examined bone disease measures and related factors among HIV-infected adults who participated in two clinical trials of combination antiretroviral therapy. Three sub-studies in the STEAL trial investigated different aspects of bone health in virologically-suppressed adults randomised to either tenofovir/emtricitabine (TDF/FTC) or abacavir/lamivudine (ABC/3TC). The first study compared bone metabolism between arms and identified predictors of bone loss over 96 weeks. The second study evaluated bone structural parameters. The third study explored possible links between human leukocyte antigens (HLA) and BMD. Bone loss over 96 weeks was also examined in a sub-study of Second-Line, a study in adults from middle-income countries virologically failing standard first-line therapy, randomised to raltegravir+lopinavir/ritonavir or conventional 2-3 nucleoside/nucleotide reverse transcriptase inhibitor (N(t)RTIs)+lopinavir/ritonavir therapy. STEAL participants randomised to TDF/FTC experienced significantly greater BMD decrease compared to ABC/3TC. Bone markers also increased with TDF/FTC, but early changes in markers did not predict bone loss. Independent predictors of reduced BMD included randomisation to TDF/FTC, lower fat mass, lower bone formation, and PI use. Tenofovir use at the time of randomisation was associated with reduced bone structure measures, but no structural parameter changed significantly over 96 weeks. A possible association was found between BMD and HLA supertypes, particularly HLA-DQ3. In Second-Line, there were greater BMD decreases among N(t)RTI-recipients compared with raltegravir. Most of the BMD decrease occurred in the first 48 weeks of treatment with little change thereafter. Independent predictors for BMD decrease included lower baseline body mass index, longer tenofovir exposure, greater change in CD4+ from baseline to week 12, and higher baseline plasma HIV-RNA. Taken together, these studies contribute additional evidence regarding the complex relationship between HIV-infection, traditional risk factors, viral and immune mediators, antiretroviral therapy (particularly tenofovir) and bone quality. Further research might allow for more effective clinical management of HIV-infected patients at risk of bone disease and fractures.

Background: Despite the success of antiretroviral treatment (ART) in human immunodeficiency virus (HIV), the associated toxicities are complex to manage and compromise treatment benefits. Prevention and treatment of chronic toxicities such as cardiovascular disease (CVD), metabolic disorders, lipodystrophy, and osteoporosis are essential to ensure patient well being. This thesis aimed to provide more information on these toxicities in two clinical trial settings. Methods: Three sub-studies of the STEAL clinical trial examined the toxicities associated with ABC/3TC and TDF/FTC. The first study compared cardiovascular safety profiles of the two ART by examining CVD biomarkers. The second identified baseline predictors of limb fat recovery. A final study identified specific HLA genotypes associated with body composition changes. The final chapters of the thesis examined ART toxicities in HIV participants failing their first-line therapy in the SECONDLINE study. Lipodystrophy, metabolic disturbances, cardiovascular risk and bone mineral density were examined in participants randomised to either 2-3 nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) plus lopinavir/ritonavir (LPV/r) or to raltegravir plus LPV/r. Results: The primary STEAL study was the first randomised controlled trial to support the finding that ABC was associated with adverse cardiovascular affects. We found there were no consistent differences in biomarker levels of immune activation, coagulopathic disorders or endothelial dysfunction as a biological explanation for this adverse effect. Limb fat gain was similar with both ABC/3TC and TDF/FTC treatment and the baseline predictors of greater limb fat gain were thymidine N(t)RTI use, high glucose, high interleukin 6 and low limb fat. The HLA analysis demonstrated that participants carrying one or more of the HLA supertypes A01, B08 and DQ2 may be resistant to thymidine analogue-induced lipoatrophy. SECONDLINE study participants switching to LPV/r plus raltegravir improved limb fat similar to the N(t)RTI plus LPV/r regimen, but worsened total:HDL cholesterol ratio over 48 weeks. In addition, LPV/r plus raltegravir was associated with less bone loss that the LPV/r plus 2-3 N(t)RTI. Thereby demonstrating that raltegravir may be a safe alternative to standard second-line therapy. Conclusion: Endeavours to understand treatment-related toxicities are important initiatives to assist with long-term, effective use of ART in HIV infected individuals.

In 2011 greater than 518,000 marathon finishing times were recorded in the USA, nearly 60% were male. It is commonly accepted that regular weight-bearing physical activity can promote bone health throughout the lifespan. However, available literature suggests male runners may have a decreased bone mineral density (BMD), specifically in the lumbar spine and radius. Researchers speculate a decrease in BMD may be the result of several factors including inadequate diet, low testosterone, and/or genetic predisposition. Decreased testosterone levels are present in males engaged in prolonged endurance activities such as running. Energy availability (EA) is the amount of dietary energy remaining for other body functions after exercise training. Low EA may be the underpinning factor for decreases BMD, and is the outcome of inadequate dietary intake and/or increasing exercise energy expenditure. PURPOSE: To explore the relationship between EA, testosterone level, blood lipids and BMD in male athletes. METHODS: Dual-Energy X-Ray Absorptiometry (DXA) bone density scans were completed for total body, non-dominant hip, lumbar spine, non-dominant forearm, and body composition. Additionally, blood samples, three-day food and activity records, and three-day accelerometry data were collected and analyzed. RESULTS: A total of 41 subjects completed the study. Bone density results revealed that 5 of 41 subjects had bone insufficiency (BMD Z-score less than or equal to -1) in the femoral neck, 13 in the lumbar spine (L1-L4) and 18 in the ultra-distal radius. Ten of 41 subjects presented with low testosterone and 24 subjects had a suboptimal blood lipid profile. Energy availability results revealed that mean EA was 32.1 kcals per kg FFM and 19 of 40 subjects consumed less than 30 kcals per kg FFM. CONCLUSION: The detriments of low bone density can be severe and irreversible and male endurance runners are practicing habits that may support low BMD. Consequently, it is important to gain more insight into the nutrition attitudes and behaviors of male distance runners that possibly elicit negative consequences to help future prevention and education efforts

Abstract: Background The adjacent vertebrae and endplates are important to maintaining the integrity and functions of the intervertebral disc. Yet, they have received relatively little attention and their roles in disc degeneration (DD) and back pain remain unclear. Purpose The purpose of this doctoral research was to describe the morphometrics of the lumbar vertebral endplate, characterise endplate lesions, and explore the roles of morphological and pathological findings of the adjacent vertebrae and vertebral endplates in the pathogenesis of DD. Materials and Methods Studies were extended from a cadaveric lumbar spine archive of 157 Caucasian men (mean age 51.2 years). Using discography, DD was rated as absent, slight, moderate or severe. A sample of 150 vertebrae was scanned with micro-CT to explore the relationship between vertebral bone mineral density (BMD) and DD, BMD and thickness of the vertebral endplate and DD. Using a laser digitizer, morphological measurements of 591 vertebral endplates were quantified to determine their associations with DD. In addition, a total of 1148 vertebral endplates were visually examined to determine the prevalence rate, pathological classification, and distribution patterns of lumbar endplate lesions, as well as their associations with age, DD and back pain history. Results and Conclusions Higher BMD of the vertebral body, but not that of the whole vertebra, was associated with more severe adjacent DD. Among the endplate morphological measurements measured, including size, thickness, circularity, concavity and BMD, only greater endplate thickness and size were found to associate with more DD. Yet, the associations observed were relatively weak, suggesting a modest role of endplate morphometrics in DD. In contrast, endplate lesions were common findings in the lumbar spine of mid-aged men and were strongly associated with DD. Furthermore, four types of endplate lesions were identified, including Schmorl’s nodes, fracture, erosion and calcification. These lesions had distinct morphological features, different distribution patterns and varying degrees of association with adjacent DD. Lumbar endplate lesions tended to affect both adjacent endplates of a disc together and appear to play an important role in DD. Findings also suggest endplate lesions may be a source of back pain.

Background: Osteoporosis becomes a major health problem in aging populations, and this disease increases the risk of bone fractures, leading to disability and mortality. Cissus quadrangularis L. (CQ) has been reported to have beneficial effects on bone metabolism; however, there has been no investigation to identify the active compounds responsible for this activity. Objective: Sequential extracts (hexane, dichloromethane, ethanol, and water) and freeze-dried CQ juice were investigated to determine their effects on bone metabolism in an ovariectomized (ovx) mouse model. Methods: Six-week-old ICR mice were divided into eight groups: sham-operated, ovx-control, estradiol (E2)- treated and five CQ-treated ovx-mouse groups (n = 3). The CQ extracts were orally administered at a dose equivalent to 5g of crude powder/kg/day for 8 weeks. Bone mineral densities (BMD) of the femur and tibia, serum levels of osteocalcin (bone formation marker) and TRAP5b (bone resorption marker), and histomorphological change of lumbar spine were determined at the end of the experiment. Results: The BMD of the femur and tibia in the hexane-treated group were elevated to the same level as those of sham-operated group. This BMDs correlated with restoration of the trabecular bone of the lumbar spine, which was only observed in the hexane-treated group. These results were also supported by the lowest serum levels of osteocalcin and TRAP5b observed in this group, compared to the ovx-control and E2-treated groups, representing a decrease in the bone turnover rate. Neither signs of abnormality nor pathological changes of internal organs were observed after the experiment. Conclusion: The hexane extract possessed antiosteoporotic activity in ovariectomized mice without any toxicity throughout the experiment. Therefore, the hexane extract is the most interesting for further bioassay-guided purification of pharmacologically active compounds.

Bone mass and strength changes proceeding weight loss in obese individuals are important for determining risk for skeletal fragility. Understanding the relationship between obesity and bone strength is significant for describing bone's response to changes in body composition. The three manuscripts presented in this dissertation focus on obese adult populations (aged 18 - 64 years). Peripheral quantitative computed tomography (pQCT) was used to assess volumetric bone mineral density, bone geometry, indices of bone strength, and muscle cross-sectional area. Manuscript I reviews the association between bariatric surgery, changes in bone mineral density, and osteoporosis. The review demonstrated significant loss of bone density at hip and spine sites in the first year following bariatric procedures. However, existing research fails to support the concern over risk of osteoporosis in these individuals. Manuscript II of this dissertation, a cross-sectional study, demonstrated that despite greater absolute bone strength observed in obese women compared to their healthy-weight counterparts, bone strength was low relative to their high body weight. Manuscript III was a prospective observational pilot study to examine changes in bone strength and body composition in morbidly obese adults submitted for bariatric surgery. The results showed that bariatric surgery produced significant weight loss that was predominately due to reduction in fat mass, rather that fat-free mass. Despite significant weight loss bone strength indices were not compromised, suggesting that maintenance of lean mass may preserve bone strength. This dissertation contributes to the knowledge base in several ways. First, it provides a comprehensive summary of bariatric surgery and bone density research, while providing an alternative perspective for interpreting dual x-ray absorptiometry-based bone outcomes. Second, bone strength was assessed using pQCT, which provides an understanding of bone from a mechanical perspective that has not been used when interpreting bone outcomes in severely obese populations. Finally, this dissertation includes the first known study to examine changes in bone strength following bariatric surgery in morbidly obese individuals.

Total parenteral nutrition (TPN) dependent infants and children with intestinal failure (IF) are at risk for reduced bone mineral content and density owing to inflammation, disturbances in the growth hormone-insulin-like growth factor (IGF)-1 axis or vitamin D and Ca metabolism, and/or aluminum toxicity. We performed a cross sectional study comparing infants and children with intestinal failure with duos of age, sex, and race matched controls. Bone mineral content (BMC) and density (BMD) of the lumbar spine was measured by dual x-ray absorptiometry, and serum cytokines, aluminum, IGF-1 and IGF-BP3, parathyroid hormone (PTH), 25(OH) Vitamin D, and 1, 25(OH)2 Vitamin D were measured. Generalized estimating equation models accounting for matching were used for comparisons. BMC and BMD were lower (15% and 12%) in IF participants than controls (p=0.0009 and p=0.004). However, group differences were attenuated (to 3% and 7%, respectfully) and did not differ (p=0.40 and p=0.07) when adjusted for length and weight. Length and weight percentiles were significantly lower in IF versus control participants (12.5% vs. 63%, p

STUDY 1 Aim: To compare the effects of Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) on changes in bone mineral density (BMD), weight loss and blood biomarkers related to bone turnover, hormonal, and nutrient status. Subjects: Nine bariatric surgery patients. Methods: Patients had a DXA bone scan and fasting blood draw at baseline, three, and six months following surgery. Results: RYGB patients had greater weight loss vs. LAGB at both three (mean loss: 19 vs. 9%) and six months (26 vs. 11%), p

MOTIVATION: Previous research has been focused on the potentially harmful aspects of excess protein on bone health, largely based on the calciuria induced by particular amino acids. However, recent studies are showing no deleterious effects on actual whole-body bone mineral density (BMD). Examining specific skeletal sites that are commonly used to assess BMD may reduce some of the limitations of whole-body DEXA scans (e.g. large individuals) and provide more information. HYPOTHESIS: Our hypothesis is that protein-seeking Caucasian male resistance trainers will not differ from non-protein-seeking peers in site-specific BMD. METHODOLOGY: Eighteen resistance athletes (training > 3y) will be studied using dual x-ray absorptiometry (DEXA) scans of the femoral neck and lumbar spine, as well as self-reported 7-day diet and exercise logs. Group differences will be analyzed using unpaired t-tests (Statistica, Statsoft, Inc.).

Introduction: The benefits of regular exercise on skeletal health have been well-documented in terms of stimulation of bone accrual and bone maintenance. Medium-impact sports activities such as running have been demonstrated to exert site-specific enhancement of bone mass in the lower appendicular skeleton. However, elite female runners engaged in high intensity training and sports activity may also be at risk of amenorrhea and low bone mineral density (BMD) resulting from inadequate caloric intake. Purpose: To investigate the effect of intensive exercise and maintenance of adequate caloric intake on BMD in a group of elite female runners. Methods: This study represents a secondary assessment of existing data that were obtained between 1994 and 2009. Using dual-energy X-ray absorptiometry, a group of elite runners (n=11) in this study was screened in the Laboratory for Elite Athlete Performance at Georgia State University. This was a longitudinal study in which three sequential measurements of BMD, as well as fat and lean tissue body composition of each athlete took place. The average interval between measurements was 1.1 years and 2.6 years respectively. Regional BMD measurements for head, arms, legs, trunk, ribs, pelvis, and spine were assessed, as well as the value for total body BMD. The study participants also received dietary counseling emphasizing daily caloric balance and adequate calcium intake. Results: The average age of the runners increased from 24.59 (±4.41) to 28.14 (±5.94) years over the study. This was accompanied by an increase in body mass (54.98±3.54 to 56.11±4.07 kg), while height remained constant. The average body mass index (BMI) of the subjects increased from 19.34 to 19.71 kg/m2, largely due to an increase in total per cent body fat (13.97±2.96% to 16.01±4.28%). Average regional and total BMD values increased over the study period and increases were between 2 and 4%. A majority of subjects (n=7) had a BMI>19 kg/m2, while a sub-group of runners (n=4) had a BMI˂19 kg/m2. Mean trunk, pelvis and spine BMD parameters for the two BMI groups were significantly different (p˂0.05), with reduced BMD values in the lower BMI sub-group. The average T-scores associated with arm BMD were considerably lower than T-scores associated with leg BMD values in the runners. The average T-scores for leg BMD values were almost two standard deviations higher than leg BMD values for a reference population at peak bone mass. Two subjects were osteopenic, resulting in an 18% prevalence rate of osteopenia in the group of runners. Conclusions: The majority of elite runners in this study exhibited a positive trend in BMD parameters. This was reflected as increased total as well as regional BMD values. Increased body mass in addition to the activity of running positively contributed to bone mass via a weight-bearing effect. Increased adipose tissue may also have been a source of endocrine hormones such as estrogen and leptin, which exert a positive effect on bone accrual.

Osteoporosis is a health issue that is becoming more prominent in today's society. Bone mineral density (BMD) tests have the ability to: detect low bone density before a fracture occurs and predict the chances of future fractures occurring and determine an individual's rate of bone loss. Purpose: (1) Determine the relationship between BMD t-scores measured by the QUS and RA devices, compared to the DXA measurement, the gold standard. (2) Examine the agreement between osteoporosis classifications produced by the QUS and RA devices, compared to those produced by the DXA, the gold standard. Methods: 132 subjects reported to the Human Performance lab in Hanner Field house to complete a university approved informed consent, a short questionnaire and data collection. The subjects were volunteers from the Georgia Southern Community. All subjects were 18 years of age or older and were not pregnant. The Metriscan applied radiographic absorptiometry to estimate an individual's relative phalangeal bone density of the three middle fingers. The GE Lunar DEXA device provided a total body non-invasive and precise method of measuring BMD. The device used x-ray densitometry techniques to obtain these measurements. The Hologic Sahara UBA575 applied ultrasound to obtain BMD at the heel. Results: The only significant agreement between T-scores was seen with the DXA and RA (r=.624, p

Introduction: The incidence of hip fracture is increasing and the associated costs to individuals and the community needs to be vigorously addressed. This study was a randomized controlled intervention designed to examine the effects of a simple-to-do, easy-to-implement exercise programme on the elements of hip fracture risk which are known to be amenable to exercise therapy. Methods: Forty-five volunteers were randomly assigned to one of three groups. All groups attended one line dance class per week. Two groups additionally performed progressively loaded squats five times a week. One group also performed four foot stomps twice daily five times per week. Hip fracture risk (HFR), broadband ultrasound attenuation (BUA), proximal femoral (PF) and lumbar spine (LS) bone mineral density (BMD), squats number, and balance variables were measured. Results: There were no changes in HFR, BUA, PF or LS BMD, however, a strong positive stomps compliance effect was noted for BUA (r = 0.73, p = 0.003) and for PF BMD (r = 0.79, p = 0.002). Squats number increased in all participants, especially in those performing all three activities (p = 0.001). Single Leg Stance (SLS) times increased (p &lt 0.01), and Timed Up and Go (TUG) times decreased (p &lt 0.01) in all participants who complied with the protocol of squatting and stomping. Forward and lateral step velocities did not change. Conclusions: Our novel intervention conferred positive benefits on the skeletons of independent living, postmenopausal women. Other indices of fall and fracture risk, including muscle strength and balance, improved in all participants suggesting a beneficial effect of line dancing on these factors.

The purpose of the study was to examine the relationship and comparisons of athletic amenorrhea and bone mineral density in adolescent, cross-country runners. Subjects: Twenty-eight female adolescent cross-country runners (Mean Age + SD = 15.0 + 1.3 years); consisting of seventeen eumenorrheics & eleven amenorrheics. Design: The design consisted of a sixmonth longitudinal design in which the subjects were measured before and after cross-country season for height, weight, and lean tissue (LT), body fat (BF), bone mineral content (BMC), and bone mineral density (BMD) using whole-body scan densitiometry with a Lunar Dual-energy X-ray Absorptiometer (DXA). Run performance, weekly training volumes, menstrual dysfunction, menarchal age, nutritional information, and stress fractures were reported by the subjects. Statistical analyses consisted of Pearson product-moment and partial correlations to examine the associations of the variables, paired t-tests to measure seasonal body composition changes, multivariate analysis (MANOVA & MANCOVA) to investigate the subgroup differences of variables, and simple linear regression to determine the best body composition predictor variable for BMD. Results: The eumenorrheic subgroup's BMD was significantly greater than the amenorrheic subgroup's BMD (F(1, 54) = 16.22, p

The main hypotheses tested within this research focussed on the identification of polymorphisms within Runx2, and the classification of these with respect to bone mineral density (BMD). A separate set of hypotheses focussed upon the effects of calcium treatment in an elderly population, to identify any differences in BMD, bone mineral content (BMC) and bone area between the specific genotypes identified. The initial research strategy included taking subjects’ from the extremes of a population to identify alleles specifically related to the bone mineral density trait. The idea was tested using Runx2, the well known osteoblast transcription factor. From a population of 1300 subjects (from the Geelong Osteoporosis Study: the GOS) the age-weight adjusted femoral neck BMD was ranked and the upper and lower deciles taken to represent the adjusted extremes. After adjusting and ranking, the two groups (n=130 each) were not significantly different for age or weight. In these 260 subjects, we identified 16 allelic variations within the Runx2 gene and gene promoters (P1 and P2), and characterized these novel variations with respect to BMD strata by genotype using DHPLC.

High body weight seems protective of bone mass, specifically bone mineral content (BMC) and bone mineral density (BMD), thereby reducing the risk of osteoporosis. Cognitive eating restraint (CER), diet composition, and the satiety hormone, leptin, produced by adipocytes, are associated with body mass and may also influence bone mass. Few studies have examined these relationships. To investigate the relationship between leptin and CER score, 36 premenopausal, healthy weight women, as defined by body mass index (BMI) of 18-25 kg/m2, aged 18-25 years were studied. Women were categorized by baseline Eating Inventory questionnaire scores into either the high CER group (score > 9, n = 20) or low CER group (score < 9, n = 16). Serum leptin concentration was significantly lower in the low CER group versus high CER group at baseline. A positive relationship between serum leptin concentration and body fat mass and body fat % in normal weight women despite differences in CER scores was observed. In a separate study, overweight and obese women, (BMI > 25 to < 43 kg/m2), aged 32-45 years, were randomly assigned to either a low-carbohydrate, high-protein (LCHP) or low-fat, high-carbohydrate (LFHC) diet for 12 weeks. Serum leptin concentration was significantly greater in the LCHP versus the LFHC diet group at 12 weeks (p < 0.05). Over time, significant decreases in serum leptin concentration, BMI, body weight, total lean mass, total fat mass, and body fat % were observed in both diet groups. Serum leptin concentration was positively associated with body weight, fat mass, and body fat % regardless of diet consumed. Both studies are novel in their respective populations and show no direct link between leptin and bone mass when considered in the context of CER or diet composition.

Low bone mineral density (BMD) is a key risk factor for osteoporosis and related fractures, which are prevalent worldwide and result in significant morbidity, mortality and economic consequences. Most epidemiological studies of bone loss focus on post-menopausal women, yet several recent studies suggest bone loss commences immediately after bone mass peaks, well prior to menopause. This dissertation examined the relationship between pre- and peri-menopausal variation in BMD and hallmarks of menopausal transition, including greater fluctuation in endogenous hormone levels, increased anovulatory cycles and shorter luteal phases. The analyses employed data from two large population-based studies of pre- and peri-menopausal women: the Michigan Bone Health Study (MBHS) [N=660] and the Daily Hormone Study (DHS), a sub-study of the Study of Women Across the Nation [N=643]. Chapter 2, a longitudinal analysis of MBHS data, found that bone loss at the femoral neck and lumbar spine was significantly associated with decreased serum estradiol concentrations and increased serum FSH concentrations. Also, women experience bone loss at the femoral neck as early as 24 years of age. Chapter 3, the first study to evaluate the association between BMD and ovulatory function in a multi-ethnic, community-based cohort of pre- and peri-menopausal women, offered no evidence that changes in ovulatory function, as characterized by menstrual cycle length or evidence of a single anovulatory event, were linked to BMD. However, lower BMD was significantly associated with direct measures of the variation in endogenous hormones (lower uE1c, higher uFSH) prior to the final menstrual period. Finally, Chapter 4 used DHS data to evaluate whether urinary sex steroid and gonadotropin hormone profiles across a single menstrual cycle varied by BMD level. This novel analysis concluded that the hormone profiles of pre- and peri-menopausal women with low BMD did not differ significantly from those without low BMD. Instead, the probability of low BMD was significantly associated with cumulative hormone exposure. These findings, by advancing understanding of the association between variation in menstrual cycle characteristics and endogenous hormone levels and pre- and peri-menopausal BMD, inform public health interventions aimed at minimizing bone loss during the menopausal transition.

Low-carbohydrate, high-protein (LCHP) diets have been shown to induce weight loss and beneficial changes in blood lipids that suggest cardiovascular disease risk reduction; however, LCHP diets have not been adequately investigated for health effects on the skeleton. A randomized trial to determine the effects of a LCHP diet on bone mineral status, biomarkers of bone turnover, indicators of acid-base balance, calcium homeostasis and fasting lipids in healthy pre-menopausal women was conducted. Women, aged 32 - 45 y, with a body mass index between 25-41 kg/m2 were randomized into one of two diet groups: LCHP (n = 13) or high-carbohydrate, low-fat (HCLF) (n = 12). Anthropometric (body weight, lean mass, fat mass) and bone mineral density (BMD) and content (BMC) measures and markers of lipid metabolism were taken at weeks 0, 6, and 12. Measures of acid-base balance, protein metabolism, and calcium homeostasis were conducted at weeks 0, 1-4, 6, and 12. Serum osteocalcin was analyzed at weeks 0, 1, 2, 6, and 12, while urinary NTx was analyzed at weeks 0, 1 and 2. Weight loss was significant at the end of 12 weeks in both diet groups (P < 0.05) but there was no Diet x Time interaction. Total proximal femur BMD was lower in the LCHP group (P < 0.05) compared to the HCLF group by week 12. Femoral neck BMC decreased in the LCHP diet group (P < 0.05), whereas total forearm BMC increased (P < 0.05) in the HCLF diet group by week 12 of the study. Serum osteocalcin showed significant main effects of diet (P < 0.05) and time (P < 0.0001), but a Diet x Time interaction was not observed. Urinary NTx exhibited no main diet effect, time effect or Diet x Time interaction at weeks 1 or 2. Urinary pH was lower in the LCHP group compared to the HCLF group throughout the study (P < 0.0001). Urinary calcium excretion was higher in the LCHP group and lower in the HCLF group (P < 0.0001) compared to baseline values at all intervals of the study. Urinary phosphorus excretion exhibited a significant diet effect (P < 0.001) and time effect (P < 0.002), while no Diet x Time interaction was observed. Total cholesterol, high-density and low-density lipoprotein cholesterol, and triacylglycerol concentrations did not differ between diets during the study. In conclusion, a LCHP diet appears to stimulate bone loss, while a HCLF diet appears to attenuate bone loss in healthy pre-menopausal women undergoing 12 weeks of weight loss.

Osteoporosis is caused by a multitude of factors. An individual’s risk for experiencing a bone fracture as a senior citizen increases without early intervention. Healthcare professionals do not have access to validated survey tools to identify young adults in need of osteoporosis prevention education, although survey tools to identify postmenopausal women at high risk for low bone mass are available. The purposes of this study were to evaluate three of these survey tools for use in a younger population, and to determine if young adults with osteoporosis risk factors received bone health education from a health professional. Forty-two men and 41 women completed surveys and health questionnaires; responses were compared to bone mineral density (BMD) and content (BMC) measurements. Healthcare professionals discussed bone health with only 13% of participants. Chi-square analysis revealed that health professionals were not more likely to discuss osteoporosis with subjects based on age or gender. Participants with T-scores ≤ -1.0 were not more likely to receive bone health education. Area under the receiving operating characteristic (AUROC) curves analysis revealed that no survey tools were able to identify moderate-risk participants at T-scores ≤ -1.0, and AUROC curves for all surveys did not exceed 0.525 at this level. Two surveys detected participants at high risk for bone disease with identical AUROC curves of 0.821 at a T-score ≤ -2.0, and 0.813 at a T-score ≤ -2.5. The AUROC curves indicate that current tools designed for older women do not detect young adults with moderately low T-scores.

Bone mineral content (BMC) and bone mineral density (BMD), measured by dual x-ray absorptiometry are used clinically to diagnose osteoporosis and estimate risk for fragility fractures. Bone mineral explains up to 70% of bone strength; however, it does not take into account bone geometry. Mechanical Response Tissue Analysis is a method of non-invasively measuring the bending stiffness (EI) of bone which is determined by the product of Young's modulus of elasticity (E) and the areal cross sectional moment of inertia (I). The aim of the current study was to determine if high intensity strength training will increase ulnar bending stiffness in young women. Forty-nine women aged 19.9 ± 1.7 yrs, trained their nondominant arm either concentrically or eccentrically in the Isokinetic modality on the Biodex® system III 3d/wk for 32 wks. The dominant arm served as the control limb (untrained). Analysis of all subjects regardless of training mode demonstrated a significant increase in ulnar EI (22% ↑, P=0.01) with no significant difference in the untrained arm. When EI results were assessed by training mode, subjects who trained eccentrically showed a significant increase for ulnar EI in the trained limb (40% ↑, P=0.01) with no significant effect on the untrained limb while concentric training demonstrated no significant gain in either the trained or untrained arm. There was no effect of time x mode of training interaction for either the trained or untrained limb. Bone mineral density and bone mineral content of the ulna increased significantly in the trained arm in both concentric and eccentric training modes (P

In summary, this study investigated the role of novel polymorphisms and rare variants of the RUNX2 gene in influencing BMD, fracture and markers of bone turnover. Two common polymorphisms were identified within the polyA repeat: an 18 base pair deletion and a synonymous alanine codon polymorphism with alleles, A and G. The A allele was associated with increased BMD and was protective against a common form of osteoporotic fracture within a Geelong population. To verify these findings the RUNX2 alleles were genotyped in 992 women from a Scottish cohort. The magnitude and the direction of the effect of the A allele was maintained in the Scottish cohort. Interestingly, the A allele was shown to exert a menopause specific effect, with postmenopausal women showing the strongest effect. On re-analysis of the GOS data the post-menopausal women were found to drive the significance identified in the cohort. The magnitude of the effect of the A allele on BMD was greater in overweight/obese postmenopausal women indicating a gene-weight interaction for RUNX2. The RUNX2 11Ala allele showed a significant relationship with decreased LS BMD in overweight/obese Scottish women. The 11Ala allele was also associated with higher levels of urinary PYD and DPD in women treated with HRT, indicating higher levels of bone turnover in carriers of the 11Ala allele. In contrast to the Scottish cohort, no significant association with heterozygous carriers of 11Ala was observed in GOS, although a significant association was detected for homozygous carriers and LS BMAD. The 11 Ala RUNX2 allele was significantly associated with decreased serum osteocalcin levels and the A allele was significantly associated with TNF in OA patients. Glutamine variants and an alanine insertion were identified within Geelong and Scottish cohorts, which showed low Z and T scores suggesting that RUNX2 variants may be related to genetic effects on BMD and osteoporosis. Polymorphism of the polyQ/polyA region of RUNX2 were identified within this study were shown to associate with significant differences in BMD. The A allele showed a significant association with increased BMD in postmenopausal women from a Geelong and Scottish cohort, with a decreased frequency of the A allele observed in Colles’ fracture patients from Geelong. The 11Ala deletion allele was significantly associated with decreased LS BMD and increases in markers of bone turnover in the Scottish cohort. A significant decrease in OC serum levels was observed in OA patients suggesting a direct effect of the allele on the transactivation of the RUNX2 gene. Rare variants of RUNX2 were identified which showed low BMD. These studies have provided insight into the role of RUNX2 in influencing BMD, further studies are required to verify the role of the A allele on BMD and fracture, the role of the rare variants and to identify the precise mechanisms behind the observed changes in BMD.