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This study aims to assess whether older adults with low muscle mass or strength, in the presence of obesity, have an increased risk of knee (TKR) and hip replacement (THR) over 13 years. 1082 community-dwelling older adults (51% women; mean age 62.9 ± 7.5 years) were studied at baseline and multiple time points over 13 years. The incidence of TKR and THR was determined by data linkage to National Joint Replacement Registry. Appendicular lean and fat mass were measured using DXA. Lower-limb muscle strength (LMS) was assessed by dynamometer. Low muscle mass and strength were defined as the lowest sex-specific tertiles for appendicular lean mass (adjusted for height and total body fat mass) and lower-limb strength, respectively. Obesity was defined as the highest sex-specific tertile for total body fat mass. Competing risk regression models were used to estimate the sub-distribution hazard ratio (SHR) for TKR and THR. Over 13 years of follow-up, 6.8% (n = 74/1082) of the participants had a TKR and 4.7% (n = 50/1066) had THR. Participants with the combination of obesity and low muscle strength (SHR   3.36, 95% CI 1.50, 7.53) but low muscle mass (SHR 1.11, 95% CI 0.52, 2.40) had a significantly increased risk of TKR, compared to individuals with neither obesity nor low muscle mass/strength. However, obesity with low muscle strength did not lead to a significantly greater risk of TKR compared to having low muscle strength or obesity alone. There was no evidence for an association between obesity with low muscle mass or strength and THR (all p > 0.05). This finding suggests that combining muscle and fat assessments to predict the future risk of TKR is no better than each condition on its own.

Aim: To determine whether older adults with low muscle mass (sarcopenia) and strength (dynapenia), in the presence of osteoporosis/osteopenia, have an increased risk of fracture and mortality over 10 years, compared to those with low muscle or low bone mass alone or with neither condition., Methods: 1032 participants (52% women; mean age 62.9 ± 7.4 years) were prospectively followed for 10 years. Mortality was ascertained from the death registry and fractures were self-reported. Baseline appendicular lean mass (ALM) was assessed using dual-energy X-ray absorptiometry and normalised to body mass index (BMI). Hand grip strength (HGS) was assessed by dynamometer. Osteosarcopenia and osteodynapenia were defined as having T-scores of the total hip and/or lumbar spine bone mineral density (BMD) < -1 combined with being in the lowest 20% of the sex-specific distribution for ALM/BMI or HGS respectively., Results: Incident fracture risk was significantly higher in participants who were osteodynapenic (RR = 2.07, 95% CI: 1.26-3.39), dynapenic alone (RR = 1.74, 95% CI: 1.05-2.87), and osteopenic alone (RR = 1.63, 95% CI: 1.15-2.31), compared to those without dynapenia or osteopenia. Mortality risk was significantly higher only in participants with osteosarcopenia (RR = 1.49, 95% CI: 1.01-2.21) compared to those without sarcopenia or osteopenia. However, osteosarcopenia and osteodynapenia did not lead to a significantly greater fracture or mortality risk compared to having these conditions on their own., Conclusion: These findings suggest that the combined effect of osteopenia and sarcopenia or dynapenia on fracture and mortality risk, respectively, may not be greater than that of each individual condition., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aims: This study aims to describe the associations of low muscle mass, handgrip (HGS) and lower-limb muscle strength (LMS) with health-related quality of life (HRQoL) over 10 years in community-dwelling older adults., Methods: Participants (N = 1002; 51% women; mean age 63 ± 7.4 years) were prospectively followed for 10 years. HRQoL was measured using the validated assessment of quality of life (AQoL) instrument. Appendicular lean mass (ALM) was assessed using dual energy X-ray absorptiometry and normalized to body mass index (BMI). HGS and LMS were assessed using dynamometers. Low ALM/BMI (ALM/BMI LOW ), LMS (LMS LOW ) and HGS (HGS LOW ) at baseline were defined as the lowest 20% of the sex-specific distribution for each measure. Linear mixed effect regression models, adjusting for confounders, were used to estimate the association between ALM/BMI LOW , LMS LOW , and HGS LOW at baseline and HRQoL over 10 years., Results: Participants with LMS LOW (β = -0.061, 95% CI: -0.089, -0.033) and women (β = -0.089, 95% CI: -0.129, -0.049) but not men (β = -0.023, 95% CI: -0.064, 0.019) with HGS LOW had clinically meaningful reductions in HRQoL over 10 years compared to those with normal strength. There was a weaker but statistically significant association between ALM/BMI LOW and 10-year HRQoL (β = -0.038, 95% CI: -0.068, -0.008)., Conclusions: Lower-limb muscle strength and handgrip strength (in women only), which can be easily measured in clinical practice, appear more important than muscle mass for HRQoL., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objectives: To evaluate the associations between an objective measure of different intensities of physical activity, upper- and lower-limb muscle strength and psychomotor performance and set-shifting domains of cognitive executive function in older adults., Design: A cross-sectional study., Methods: From the Tasmanian Older Adult Cohort Study, 188 community-dwelling older adults (53.7% female; mean age±SD 63.98±7.3 years) undertook 7-day physical activity behaviour monitoring using an accelerometer. Dynamometers were used to assess leg extension strength. The Trail Maker Tests were used to measure psychomotor processing speed and set-shifting performance., Results: When controlling for age, smoking history, alcohol intake, educational achievement and neuropsychological functioning, higher levels of light physical activity, but not sedentary behaviour or moderate or vigorous physical activity, was found to be associated with better set-shifting performance. Neither physical activity behaviour or muscle strength were found to be associated with psychomotor performance. In addition, older age, greater alcohol intake, and lower levels of educational attainment, verbal learning and memory performance were significantly associated with lower scores on the set-shifting task; whereas older age and reduced neuropsychological functioning were associated with lower psychomotor processing speed scores., Conclusions: Light physical activity is associated with higher executive functioning in community-dwelling older adults and this strengthens the evidence supporting exercise as a neuroprotective agent. Further studies are needed to understand why light physical activity behaviour positively influences executive functioning, and how such physical activity can be implemented into the daily routine of older adults., (Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Studies examining the association between muscle size, muscle strength, and bone mineral density (BMD) are limited. Thus, this study aimed to describe the association between hip muscles cross-sectional area (CSA), muscle strength, and BMD of the hip and spine. A total of 321 subjects from the Tasmanian Older Adult Cohort study with a right hip MRI scan conducted between 2004 and 2006 were included. Hip muscles were measured on MR images by OsiriX (Geneva) software measuring maximum muscle CSA (cm(2)) of gluteus maximus, obturator externus, gemelli, quadratus femoris, piriformis, pectineus, sartorius, and iliopsoas. Dual-energy X-ray absorptiometry measured total hip, femoral neck, and spine BMD, and lower limb muscle strength was assessed by dynamometer. Muscle CSA of the hip flexors (pectineus, sartorius, and iliopsoas) and the hip rotators, obturator externus, and quadratus femoris were associated with both total hip and femoral neck BMD (all p < 0.05). The associations between CSA of pectineus and sartorius and BMD were stronger in women (p = 0.01-0.001) compared to men (p = 0.12-0.54). Additionally, only gemelli CSA was associated with BMD of the spine (p = 0.002). Gluteus maximus and piriformis showed no relationship with BMD. CSA of most hip muscles (except gluteus maximus and gemelli) were positively associated with leg strength (p = 0.02 to <0.001). Lastly, leg strength was weakly associated with BMD (p = 0.11-0.007). Hip muscle CSA, and to a lesser extent muscle strength, were positively associated with hip BMD. These data suggest that both higher muscle mass and strength may contribute to the maintenance of bone mass and prevention of disease progression in older adults.

Objectives: To determine whether obesity concurrent with sarcopenia (low muscle mass) or dynapenia (low muscle strength) is associated with increased falls risk in middle-aged and older adults., Methods: 5-year prospective cohort study including 674 community-dwelling volunteers (mean ± SD age 61.4 ± 7.0 years; 48% female). Sarcopenia and dynapenia were defined as lowest sex-specific tertiles for dual-energy X-ray (DXA)-assessed appendicular lean mass (adjusted for height and fat mass) or lower-limb strength, respectively. Obesity was defined as the highest tertiles of DXA-assessed total or trunk fat mass. Change in falls risk was calculated using the Physiological Profile Assessment (z-scores: 0-1 = mild increased risk; 1-2 = moderate increased risk; >2 = marked increased risk)., Results: Multivariable linear regression analyses revealed mild but significantly increased falls risk scores for dynapenic obesity (change in mean z-score compared to non-dynapenic, non-obese group: 0.33, 95% CI 0.06-0.59 [men] and 0.46, 95% CI 0.21-0.72 [women]) and dynapenia (0.25, 95% CI 0.05-0.46 [women only])., Conclusions: Dynapenic obesity, but not sarcopenic obesity, is predictive of increased falls risk score in middle-aged and older adults. In clinical settings, muscle function assessments may be useful for predicting falls risk in obese patients., (Copyright © 2014 The Obesity Society.)

Osteoarthritis (OA) is a common joint disorder for which there is no cure. Current treatments are suboptimal. Exercise is a core treatment for knee OA, with muscle strengthening exercise commonly recommended. Yoga is a mind-body exercise intervention that can improve flexibility, muscle strength, balance, and fitness and potentially reduce symptoms of OA. However, there is a scarcity of robust, high-quality conclusive evidence on the efficacy of yoga in knee OA. We are currently conducting the first randomised comparative effectiveness and cost-effectiveness trial of a yoga program compared with a strengthening exercise program in patients with symptomatic knee OA. This study protocol describes the design and conduct of this trial. The YOGA study is a phase III, single-centre, parallel, superiority, randomised, active-controlled trial which will be conducted in Hobart, Australia. One hundred and twenty-six participants (63 in each arm) aged over 40 years with symptomatic knee OA will be recruited from the community and randomly allocated to receive either a 24-week yoga program (3×/week) or a strengthening exercise program (3×/week). The primary outcome will be change in knee pain over 12 weeks, assessed using a 100 mm visual analogue scale (VAS). The secondary outcomes include change in knee pain, patient global assessment, physical function, quality of life, gait speed, biomarkers, and others over 12 and 24 weeks. We will also assess whether the presence of neuropathic pain moderates the effects of yoga compared to strengthening exercise. Additional data, such as cost and resource utilization, will be collected for the cost-effectiveness analysis. The primary analysis will be conducted using an intention-to-treat approach. Adverse events will be monitored throughout the study. Once completed, this trial will contribute to the knowledge of whether yoga can be used as a simple, effective, low-cost option for the management of knee OA, thus saving economic costs in the healthcare system. [ABSTRACT FROM AUTHOR]

Background: Skeletal muscles are essential components of the neuromuscular skeletal system that have an integral role in the structure and function of the synovial joints which are often affected by osteoarthritis (OA). The aim of this study was to identify the baseline metabolomic signatures for the longitudinal reduction of muscle strength over 10 years in the well-established community-based Tasmanian Older Adult Cohort (TASOAC). Methods: Study participants were 50–79 year old individuals from the TASOAC. Hand grip, knee extension, and leg strength were measured at baseline, 2.6-, 5-, and 10-year follow-up points. Fasting serum samples were collected at 2.6-year follow-up point, and metabolomic profiling was performed using the TMIC Prime Metabolomics Profiling Assay. Generalized linear mixed effects model was used to identify metabolites that were associated with the reduction in muscle strength over 10 years after controlling for age, sex, and BMI. Significance level was defined at α=0.0004 after correction of multiple testing of 129 metabolites with Bonferroni method. Further, a genome-wide association study (GWAS) analysis was performed to explore if genetic factors account for the association between the identified metabolomic markers and the longitudinal reduction of muscle strength over 10 years. Results: A total of 409 older adults (50% of them females) were included. The mean age was 60.93±6.50 years, and mean BMI was 27.12±4.18 kg/m2 at baseline. Muscle strength declined by 0.09 psi, 0.02 kg, and 2.57 kg per year for hand grip, knee extension, and leg strength, respectively. Among the 143 metabolites measured, 129 passed the quality checks and were included in the analysis. We found that the elevated blood level of asymmetric dimethylarginine (ADMA) was associated with the reduction in hand grip (p=0.0003) and knee extension strength (p=0.008) over 10 years. GWAS analysis found that a SNP rs1125718 adjacent to WISP1gene was associated with ADMA levels (p=4.39*10-8). Further, we found that the increased serum concentration of uric acid was significantly associated with the decline in leg strength over 10 years (p=0.0001). Conclusion: Our results demonstrated that elevated serum ADMA and uric acid at baseline were associated with age-dependent muscle strength reduction. They might be novel targets to prevent muscle strength loss over time. [ABSTRACT FROM AUTHOR]

Background: This study aims to describe the relationships between physical activity (PA), body composition, and multimorbidity over 10 years.Method: Participants (N = 373; 49% women; average age 61.3 ± 6.7 years) were followed for 10 years. Multimorbidity was defined by self-report as the presence of 2 or more of 12 listed chronic conditions. PA (steps per day) at baseline was assessed by pedometer, handgrip strength (HGS) by dynamometer, and appendicular lean mass (ALM) and total body fat mass by dual-energy x-ray absorptiometry. Relative HGS and ALM were calculated by dividing each body mass index (BMI). Regression cubic splines were used to assess evidence for a nonlinear relationship.Results: After 10 years, 45% participants had multimorbidity. There was a nonlinear relationship between PA and multimorbidity-PA was associated with lower multimorbidity risk among individuals who engaged in <10 000 steps/d (relative risk [RR] = 0.91, 95% CI: 0.85, 0.97, per 1 000 steps/d), but not among those who participated in ≥10 000 steps/d (RR = 1.04, 95% CI: 0.93, 1.09, per 1 000 steps/d). Higher BMI (RR = 1.05, 95% CI: 1.02, 1.08, per kg/m2) and fat mass (RR = 1.03, 95% CI: 1.01, 1.04, per kg), and lower relative HGS (RR = 0.85, 95% CI: 0.77, 0.94, per 0.1 psi/kg/m2) and ALM (RR = 0.93, 95% CI: 0.88, 0.98, per 0.1 kg/kg/m2) were linearly associated with a higher risk of multimorbidity. Absolute HGS and ALM were not significantly associated with multimorbidity.Discussion: These findings highlight the potential clinical importance of maintaining adequate levels of PA and of reducing adiposity and maintaining muscle function for minimizing the risk of multimorbidity in older adults. [ABSTRACT FROM AUTHOR]

Aim: To describe the associations of between-person and within-person variability in serum 25-hydroxyvitamin D (25(OH)D), physical activity (PA), and knee pain and dysfunction with muscle mass, strength, and muscle quality over 10 years in community-dwelling older adults.Method: Participants (N = 1033; 51% women; mean age 63 ± 7.4 years) were measured at baseline, 2.5, 5, and 10 years. Lower limb lean mass (LLM) was assessed using dual energy X-ray absorptiometry, lower limb muscle strength (LMS) using a dynamometer, and lower limb muscle quality (LMQ) calculated as LMS/LLM. Knee pain and dysfunction were assessed using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index. PA was measured using pedometers. Linear-mixed effect regression models, with adjustment for confounders, were used to estimate the association of within-person and between-person variability in PA, 25(OH)D, and WOMAC scores with muscle mass, strength, and muscle quality.Results: Both between-person and within-person increases in PA were associated with LLM, LMS, and LMQ (all P < 0.05). Within-person and between-person increases in knee pain and dysfunction were associated with LLS and LMQ, but not with LLM (all P < 0.05). Between-person effects showed that higher average 25(OH)D was associated with a higher 10-year average LLM, LMS, and LMQ (all P < 0.05), whereas within-person increases in average 25(OH)D were associated with a higher LMS and LMQ, but not with LLM.Conclusions: Variability in 25(OH)D, pain, and dysfunction within an individual over time is related to muscle changes in that individual. Increasing one's own PA level further increases muscle mass, strength, and quality supporting the clinical recommendation of promoting PA to reduce age-related muscle loss. [ABSTRACT FROM AUTHOR]

Objective: Hip morphology plays a significant role in the incidence and progression of hip osteoarthritis (OA). We hypothesized that hip shape would also be associated with other key factors and tested this in a longitudinal community-based cohort combining radiographic, magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and clinical data.Methods: Baseline DXA images of the left hip of 831 subjects from the Tasmanian Older Adult Cohort were analyzed using an 85-point statistical shape model. Hip pain was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index, and muscle strength was measured using a dynamometer. Hip structural changes were assessed using MRI and radiographic OA using plain radiographs.Results: Six shape modes accounted for 68% of shape variation. At baseline, modes 1, 2, 4, and 6 were associated with radiographic hip OA; modes 1, 3, 4, and 6 were correlated with hip cartilage volume; and all except mode 2 were correlated with muscle strength. Higher mode 1 and lower mode 3 and mode 6 scores at baseline predicted hip pain at followup and higher mode 1 and mode 2 scores were associated with hip effusion-synovitis. Higher scores for mode 2 (decreasing acetabular coverage) and lower scores for mode 4 (nonspherical femoral head) at baseline predicted 10-year total hip replacement (THR), while mode 4 alone was correlated with bone marrow lesions (BMLs), effusion-synovitis, and increased cartilage signal.Conclusion: Hip shape is associated with radiographic OA, THR, hip pain, effusion-synovitis, BMLs, muscle strength, and hip structural changes. These data suggest that different shape modes reflect multiple facets of hip OA. [ABSTRACT FROM AUTHOR]