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Background: Acromegaly is associated with changes in body composition. Long-term changes following acromegaly treatment and the impact of different treatments have been less investigated., Methods: We performed a retrospective study in 201 patients with acromegaly. Body composition was assessed by dual-energy X-ray absorptiometry. To investigate the specific effects of treatment vs aging, changes in body composition were compared in one group of patients evaluated both at the time of active and controlled disease (active-to-controlled (A>C); n = 31) and in another group of patients evaluated two times while the disease was controlled (controlled-to-controlled (C>C); n = 32)., Results: In the whole cohort, insulin-like growth factor I (IGF-I) was correlated with fat (r = -0.369; P < 0.001) and lean mass (r = 0.383; P < 0.001). Patients from A>C and C>C groups were comparable for age, sex, BMI and follow-up duration (P = n.s.). Reduction in IGF-I levels was associated with an increase in fat mass and a decrease in lean mass in the A>C group, which was four and eight times more pronounced compared to the C>C group (fat mass: +39 ± 34% vs +10 ± 15%, P < 0.001; lean mass: -8 ± 8% vs -0.2 ± 6%, P < 0.001, respectively). Changes in fat mass were negatively associated with IGF-I (r = -0.450; P = 0.011) and independent of the individual therapy. The daily dose of pegvisomant correlated with fat mass (r = 0.421; P = 0.002) and insulin sensitivity index (r = -0.466; P < 0.001)., Conclusions: Treatment of acromegaly strongly impacts body composition until biochemical disease remission, characterized by an increase in fat mass and a decrease in lean mass. These changes are closely associated with the normalization of IGF-I. Thereafter, body composition changes are similar to what is observed with aging.

Background: Detection of high-risk individuals for fractures are needed. This study assessed whether level of physical activity (PA) and a musculoskeletal composite score could be used as fracture predictive tools, and if the score could predict fractures better than areal bone mineral density (aBMD)., Methods: MrOs Sweden is a prospective population-based observational study that at baseline included 3014 men aged 69-81 years. We assessed femoral neck bone mineral content (BMC), bone area, aBMD and total body lean mass by dual energy X-ray absorptiometry, calcaneal speed of sound by quantitative ultrasound and hand grip strength by a handheld dynamometer. PA was assessed by the Physical Activity Scale for the Elderly (PASE) questionnaire. We followed the participants until the date of first fracture, death or relocation (median 9.6 years). A musculoskeletal composite score was calculated as mean Z-score of the five measured traits. A Cox proportional hazards model was used to analyze the association between the musculoskeletal traits, the composite score and incident fractures (yes/no) during the follow-up period. Data are presented as hazard ratios (HR) with 95% confidence intervals (95% CI) for fracture for a + 1 standard deviation (SD) change (+ 1 Z-score) in the various musculoskeletal traits as well as the composite score. We used a linear regression model to estimate the association between level of PA, measured as PASE-score and the different musculoskeletal traits as well as the composite score., Results: A + 1 SD higher composite score was associated with an incident fracture HR of 0.61 (0.54, 0.69), however not being superior to aBMD in fracture prediction. A + 1 SD higher PASE-score was associated with both a higher composite score and lower fracture incidence (HR 0.83 (0.76, 0.90))., Conclusions: The composite score was similar to femoral neck aBMD in predicting fractures, and also low PA predicted fractures. This highlights the need of randomized controlled trials to evaluate if PA could be used as a fracture preventive strategy.

Background: Growth hormone treatment reduces fat mass and insulin sensitivity and increases lean body mass. Data are only available for short-term longitudinal changes after cessation of growth hormone treatment in young adults born small for gestational age. We aimed to assess long-term changes over a 5-year period following cessation of growth hormone treatment., Methods: We did a longitudinal study of young adults born small for gestational age and previously treated with growth hormone. Individuals were followed up for 5 years after attainment of adult height, when growth hormone treatment was discontinued: assessments were done at cessation of growth hormone treatment and at 6 months, 2 years, and 5 years thereafter. Data 5 years after cessation of growth hormone were compared with untreated age-matched controls. We used dual-energy x-ray absorptiometry to assess body composition, and did frequently sampled intravenous glucose tolerance tests to assess insulin sensitivity, acute insulin response, and the disposition index (a measure of β-cell function). This study is registered with ISRCTN, numbers ISRCTN96883876 and ISRCTN65230311., Findings: Between April, 2004, and April, 2016, we followed up 199 young adults born small for gestational age and previously treated with growth hormone, during the 5 years after cessation of growth hormone treatment. Data at 5 years for these individuals were compared with those for 51 untreated adults born small for gestational age with short stature, 92 untreated adults born small for gestational age with spontaneous catch-up growth, and 142 adults born appropriate for gestational age and unexposed to growth hormone treatment. In young adults born small for gestational age and previously treated with growth hormone, 5 years after cessation of growth hormone treatment, there were increases in fat mass (estimated marginal mean 10·73 kg [95% CI 9·95-11·50] at cessation of treatment vs 16·12 kg [14·77-17·46] at 5 years; p<0·0001), trunk fat (5·34 kg [4·94-5·73] vs 7·86 kg [7·12-8·60]; p<0·0001), and limb fat (4·87 kg [4·49-5·25] vs 7·41 kg [6·78-8·05]; p<0·0001); furthermore, lean body mass had decreased (42·41 kg [95% CI 41·09-43·73] at cessation of treatment vs 41·42 kg [40·17-42·66] at 5 years; p=0·0013). Insulin sensitivity increased within 6 months of cessation and was sustained 5 years after treatment cessation (estimated marginal mean 4·14 mU/L [95% CI 3·79-4·53] at cessation of treatment vs 6·15 mU/L [5·21-7·24] at 5 years; p<0·0001), and acute insulin response was diminished at 6 months, which persisted at 5 year follow-up (597·63 mU/L [539·62-661·86] vs 393·69 mU/L [337·56-459·15]; p<0·0001). The disposition index was increased 6 months after treatment but values at 5 years were similar to those at cessation of treatment (2483·94 [95% CI 2233·43-2762·54] at cessation of treatment vs 2367·83 [2033·43-2757·22] at 5 years; p=0·49). 5 years after cessation of growth hormone treatment, adults born small for gestational age and previously treated with growth hormone had fat mass, insulin sensitivity, and disposition index similar to those of untreated adults born small for gestational age with short stature, but lean body mass (adjusted for sex and height) was lower (46·47 kg [44·95-48·00] in those born small for gestational age with short stature vs 44·32 kg [43·35-45·30] in those born small for gestational age and treated with growth hormone; p=0·007). In adults previously treated with growth hormone born small for gestational age, at 5 years after cessation of growth hormone treatment, compared with adults born small for gestational age with spontaneous catch-up growth and adults born appropriate for gestational age, lean body mass was lower and results from frequently sampled intravenous glucose tolerance tests were similar., Interpretation: Significant changes in body composition and insulin sensitivity were recorded 5 years after cessation of growth hormone treatment in adults born small for gestational age, reflecting a loss of pharmacological effects of growth hormone. 5 years after cessation of treatment, fat mass, insulin sensitivity, and β-cell function of previously treated adults were similar to untreated adults born small for gestational age with short stature, indicating that long-term growth hormone treatment in children born small for gestational age has no unfavourable effects on metabolic health in early adulthood., Funding: Novo Nordisk Farma BV (Netherlands)., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The introduction of dual-energy X-ray absorptiometry (DXA) in the 1980s for the assessment of areal bone mineral density (BMD) greatly benefited the field of bone imaging and the ability to diagnose and monitor osteoporosis. The additional capability of DXA to differentiate between bone mineral, fat tissue, and lean tissue has contributed to its emergence as a popular tool to assess body composition. Throughout the past 2 decades, technological advancements such as the transition from the original pencil-beam densitometers to the most recent narrow fan-beam densitometers have allowed for faster scan times and better resolution. The majority of reports that have compared DXA-derived body composition measurements to the gold standard method of body composition appraisal, the four-compartment model, have observed significant differences with this criterion method; however, the extent to which the technological advancements of the DXA have impacted its ability to accurately assess body composition remains unclear. Thus, this paper reviews the evidence regarding the trueness and precision of DXA body composition measurements from the pencil-beam to the narrow fan-beam densitometers.

Dual-energy X-ray absorptiometry (DXA) has been recently used for body composition analysis in dialysis patients. It is based on the principle that X-rays passed through various body tissues have different attenuation and, therefore, can be differentiated. By using X-rays at two different energy levels, better tissue differentiation is possible compared with single energy systems. This article will review the evolution of DXA scanners and the role DXA has in assessing body composition in dialysis patients. Overall, this technique has excellent precision and holds promise for use in the serial evaluation of body composition and nutritional evaluation of dialysis patients.