Sarcopenia definitions and their association with fracture risk in older Swedish women.

The purpose of this study was to investigate the prevalence of three sarcopenia definitions and their associations with fracture risk in older Swedish women when adjusted for fracture risk assessment (FRAX)-based risk factors; 2,883 women with a mean age of 77.8 years were included. Sarcopenia was defined based on the Sarcopenia Definitions and Outcomes Consortium (SDOC; low handgrip strength [kg] and gait speed (m/s)), revised European Working Group on Sarcopenia in Older People (EWGSOP2; low appendicular lean mass index, appendicular lean mass [ALM]/height; kg/m2], and hand grip strength [kg]), and Asian Working Group for Sarcopenia (AWGS; low ALM (kg), and hand grip strength [kg]) definitions. Femoral neck T-score was obtained from dual-energy X-ray absorptiometry. All fractures, confirmed by X-ray or medical record review, were subsequently categorized as major osteoporotic fractures (MOFs) and hip fractures. Deaths were verified through regional registers. The total follow-up time was 6.4 ± 1.3 (mean ± SD) yr. Cox regression (hazard ratios [HR] and 95% CIs) analyses were performed with adjustment for age, FRAX variables, and femoral neck T-score. Sarcopenia prevalence was 4.5% (n = 129) according to SDOC, 12.5% (n = 360) for EWGSOP2, and 10.3% (n = 296) defined by AWGS. Individuals with sarcopenia defined by SDOC had a higher mortality risk than individuals without sarcopenia (HR: 3.41; 95% CI: 2.51, 4.62) after adjusting for age and FRAX variables. Sarcopenia according to EWGSOP2 and AWGS was not associated with an increased fracture risk after adjusting for age and FRAX variables. Individuals with sarcopenia defined by SDOC had a higher risk for any fractures (HR: 1.48; 95% CI: 1.10, 1.99) and MOF (HR: 1.42; 95% CI: 1.03, 1.98) compared with individuals without sarcopenia after adjusting for clinical risk factors used in FRAX. In conclusion, sarcopenia defined by SDOC, incorporating muscle function/strength, was the only sarcopenia definition associated with fracture risk in older women.

This study aimed to investigate the risk of sarcopenia on fracture risk in older Swedish women. Data were utilized from 2,883 women aged 75­80 yr in the Swedish Sahlgrenska University Hospital Prospective Evaluation of Risk of Bone Fractures cohort. Sarcopenia was defined using three different definitions, including the Sarcopenia Definitions and Outcomes Consortium (SDOC), which includes grip strength and gait speed, while the revised European Working Group on Sarcopenia in Older People (EWGSOP2) and the Asian Working Group for Sarcopenia (AWGS) definitions include appendicular lean mass measured by dual-energy X-ray absorptiometry and grip strength. The results demonstrated that SDOC-defined sarcopenia was associated with a higher mortality risk, with increased risk of any fractures, and major osteoporotic fractures, whereas the EWGSOP2 and AWGS definitions were not associated with fracture risk. In summary, the study demonstrates that sarcopenia defined by SDOC, considering muscle function and strength, rather than lean mass, was the only investigated sarcopenia definition associated with fracture risk.

Effects of Moderate- to High-Impact Exercise Training on Bone Structure Across the Lifespan: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Moderate- to high-impact exercise improves bone mineral density (BMD) across the lifespan, but its effects on bone structure, which predicts fracture independent of areal BMD, are unclear. This systematic review and meta-analysis investigated effects of impact exercise on volumetric BMD (vBMD) and bone structure. Four databases (PubMed, Embase, SPORTDiscus, Web of Science) were searched up to March 2022 for randomized controlled trials (RCTs) investigating the effects of impact exercise, with ground reaction forces equal to or greater than running, compared with sham or habitual activity, on bone vBMD and structure. Bone variables were measured by quantitative computed tomography or magnetic resonance imaging at the tibia, radius, lumbar spine, and femur. Percentage changes in bone variables were compared among groups using mean differences (MD) and 95% confidence intervals (CI) calculated via random effects meta-analyses. Subgroup analyses were performed in children/adolescents (<18 years), adults (18-50 years), postmenopausal women, and older men. Twenty-eight RCTs (n = 2985) were included. Across all studies, impact exercise improved trabecular vBMD at the distal tibia (MD = 0.54% [95% CI 0.17, 0.90%]), total vBMD at the proximal femur (3.11% [1.07, 5.14%]), and cortical thickness at the mid/proximal radius (1.78% [0.21, 3.36%]). There was no effect on vBMD and bone structure at the distal radius, femoral shaft, or lumbar spine across all studies or in any subgroup. In adults, impact exercise decreased mid/proximal tibia cortical vBMD (-0.20% [-0.24, -0.15%]). In postmenopausal women, impact exercise improved distal tibia trabecular vBMD (0.79% [0.32, 1.25%]). There was no effect on bone parameters in children/adolescents in overall analyses, and there were insufficient studies in older men to perform meta-analyses. Impact exercise may have beneficial effects on bone structure and vBMD at various skeletal sites, but additional high-quality RCTs in different age and sex subgroups are needed to identify optimal exercise protocols for improving bone health across the lifespan. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Associations of body mass index, body fat percentage and sarcopenia components with bone health estimated by second-generation high-resolution peripheral quantitative computed tomography in older adults with obesity.

PURPOSE: To investigate associations between body mass index (BMI), body fat percentage, and components of sarcopenia (muscle mass and muscle strength/power), with bone microarchitecture measured by high-resolution peripheral computed tomography (HR-pQCT) in older adults with obesity. METHODS: Seventy-four adults aged ≥ 55 years with body fat percentage ≥ 30 % (men) or ≥40 % (women) were included. Fat mass, lean mass and total hip, femoral neck, and lumbar spine areal bone mineral density (aBMD) were measured by dual-energy X-ray absorptiometry. Appendicular lean mass (ALM) was calculated as the sum of lean mass in the upper- and lower-limbs. BMI was calculated and participants completed physical function assessments including stair climb power test. Distal tibial bone microarchitecture was assessed using HR-pQCT. Linear regression (ß-coefficients and 95 % confidence intervals) analyses were performed with adjustment for confounders including age, sex, smoking status, vitamin D and self-reported moderate to vigorous physical activity. RESULTS: BMI and ALM/height2 were both positively associated with total hip, femoral neck and lumbar spine aBMD and trabecular bone volume fraction after adjusting for confounders (all p < 0.05). Body fat percentage was not associated with aBMD or any trabecular bone parameters but was negatively associated with cortical area (p < 0.05). Stair climb power (indicating better performance) was positively associated with cortical area and negatively associated with bone failure load (both p < 0.05). CONCLUSION: Higher BMI, ALM/height2 and muscle power were associated with more favourable bone microarchitecture, but higher body fat percentage was negatively associated with cortical bone area. These findings suggest that high BMI may be protective for fractures and that this might be attributable to higher muscle mass and/or forces, while higher relative body fat is not associated with better bone health in older adults with obesity.

Vitamin D supplementation and exercise for improving physical function, body composition and metabolic health in overweight or obese older adults with vitamin D deficiency: a pilot randomized, double-blind, placebo-controlled trial.

PURPOSE: Vitamin D supplementation may have non-skeletal health benefits and enhance exercise responsiveness, particularly in those with low vitamin D levels. We determined whether, compared with placebo, vitamin D supplementation taken prior to and during a 12-week exercise program improves physical function, body composition or metabolic health, in overweight and obese older adults with vitamin D deficiency. METHODS: Fifty overweight or obese older adults (mean ± SD age: 60 ± 6 years; BMI 30.6 ± 5.7 kg/m2) with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] < 50 nmol/L) were recruited. Participants were randomly allocated to receive either vitamin D3 (4000 IU/day) or matching placebo for 24 weeks. Between weeks 12 and 24, all participants completed multi-modal exercise three days per week while continuing with vitamin D/placebo. Mean changes in physical function (primary outcome: gait speed), body composition and biochemical parameters at weeks 12 and 24 were compared between groups. RESULTS: Vitamin D supplementation, with or without exercise, had no effect on gait speed. From baseline to week 12, vitamin D supplementation increased serum 25(OH)D levels (placebo: 2.5 ± 14.7 nmol/L; treatment: 43.4 ± 18.4 nmol/L; P < 0.001) and reduced stair climb times (placebo: 0.3 ± 1.0 s; treatment: - 0.2 ± 1.0 s; P = 0.046). From 12 to 24 weeks, vitamin D supplementation combined with exercise decreased waist circumference (placebo: 1.3 ± 7.3 cm; treatment: - 3.0 ± 6.1 cm; P = 0.02) and waist-to-hip ratio (placebo: 0.01 ± 0.05; treatment: - 0.03 ± 0.05; P = 0.01) relative to placebo. Vitamin D supplementation, with or without exercise, had no effect on other physical function, body composition or metabolic health outcomes. CONCLUSION: Vitamin D supplementation had no effect on most physical function, body composition or metabolic health parameters when taken alone, or during exercise, in overweight or obese older adults with vitamin D deficiency. Vitamin D-related improvements in stair climb times and waist circumference suggest that future trials should explore the effects of vitamin D on muscle power, and its effects on body composition when combined with exercise, in populations with moderate or severe vitamin D deficiency.

Sex Differences in Bone Health Among Indian Older Adults with Obesity, Sarcopenia, and Sarcopenic Obesity.

Age-related changes in fat and lean mass contribute to bone health, but these associations may be influenced by sex and ethnicity. This study investigated sex-specific associations of obesity and sarcopenia with bone mineral density (BMD) and bone mineral apparent density (BMAD) among Indian older adults. 1057 adults aged ≥ 50 years were included. Dual-energy X-ray absorptiometry (DXA) measured BMD at the hip, spine and whole-body, and BMAD was calculated as BMD/√bone area. Obesity was defined by body fat percentage (cut points; > 25% for men and > 35% for women), and sarcopenia was defined using the revised Asian Working Group for Sarcopenia classification with low hand grip strength (< 28 kg for men and < 18 kg for women) and appendicular lean mass index (< 7.0 kg/m2 for men and < 5.4 kg/m2 for women). Participants were classified into four groups: controls (no obesity or sarcopenia), obesity, sarcopenia, or sarcopenic obesity. Linear regression (ß-coefficients and 95%CI) analyses were performed with adjustments for age, smoking status, protein intake, and socioeconomic status. Prevalence of sarcopenia (37%) and sarcopenic obesity (6%) were higher in men than women (17% and 4%, respectively). Compared with controls, men with obesity had lower whole-body BMD and BMAD, but women with obesity had higher hip and spine BMD and BMAD (all p < 0.05). Men, but not women, with sarcopenic obesity, had lower hip and whole-body BMD and BMAD (all p < 0.05) than controls. Men with sarcopenia had lower BMD and BMAD at the hip only, whereas women had lower BMD at all three sites and had lower BMAD at the hip and spine (all p < 0.05), compared with controls. Obesity, sarcopenia, and sarcopenic obesity have sex-specific associations with BMD and BMAD in Indian older adults. With the aging population in India, it is important to understand how body composition contributes to poor bone health among older adults.

Associations between socioeconomic status and obesity, sarcopenia, and sarcopenic obesity in community-dwelling older adults: The Tasmanian Older Adult Cohort Study.

BACKGROUND: Social disadvantage may contribute to increased prevalence of sarcopenia and obesity. This study investigated if socioeconomic factors are associated with obesity, sarcopenia, or sarcopenic obesity (SO), in community-dwelling older adults. METHODS: This was a cross-sectional analysis of data from the Tasmanian Older Adult Cohort study. Obesity was defined by body fat percentage (Men: ≥25%; Women: ≥35%) and sarcopenia was defined as the lowest 20% of sex-specific appendicular lean mass (ALM)/height (m2) and handgrip strength. Socioeconomic factors investigated were education (tertiary degree, secondary or no secondary school), occupation (high skilled white-collar, low skilled white-collar, or blue-collar) and residential area (advantaged or disadvantaged area). Multinomial logistic regression analyses yielding odds ratios (95% confidence intervals) were performed and adjusted for potential confounders. Mediation analysis was performed. RESULTS: 1099 older adults (63.0 ± 7.5 years; 51.1% women) participated. Older adults with a tertiary degree were significantly less likely to have obesity (0.68; 0.47, 0.98) and SO (0.48; 0.24, 0.94) compared with those who had no secondary schooling. No associations were found for occupation. Similarly, older adults living in advantaged areas were significantly less likely to have obesity (0.61; 0.39, 0.95). Steps per day mediated the association between residential area and body fat percentage by 51%. CONCLUSION: Lower educational attainment, but not occupation, was associated with increased likelihood for both obesity and SO in community-dwelling older adults. Low physical activity levels in disadvantaged areas substantially contributed to higher obesity prevalence in this population. Further research is necessary to confirm whether similar associations exist in populations with greater levels of social disadvantage and to design effective community-based interventions.

Associations of accelerometer-determined physical activity and sedentary behavior with sarcopenia and incident falls over 12 months in community-dwelling Swedish older adults.

PURPOSE: This study was aimed to determine associations of accelerometer-determined time and bouts of sedentary behavior, light physical activity (LPA), and moderate-to-vigorous PA (MVPA) with sarcopenia and incident falls over 12 months. METHODS: A total of 3334 Swedish 70-year-olds were assessed for sarcopenia, as defined by the revised definition of the European Working Group on Sarcopenia in Older People. Assessments were based on low scores for appendicular lean mass (dual-energy X-ray absorptiometry), hand grip strength, and the Timed Up and Go test. For 7 days after baseline, total time and total number of bouts (≥10 min of continuous activity at a given intensity) of activity performed at sedentary, LPA, and MVPA intensities were assessed by accelerometer. Incident falls were self-reported 6 months and 12 months after baseline. RESULTS: Only 1.8% of participants had probable or confirmed sarcopenia. After multivariable adjustment for other levels of activity, only greater MVPA time was associated with a decreased likelihood of having low appendicular lean mass, low hand grip strength, and slow Timed Up and Go time as defined by the European Working Group on Sarcopenia in Older People criteria (all p < 0.05), and only MVPA time was associated with lower likelihood of probable or confirmed sarcopenia (odds ratio = 0.80, 95% confidence interval: 0.71-0.91 h/week). Similar associations were identified for total number of bouts, with no evidence of threshold effects for longer duration of bouts of MVPA. A total of 14% of participants reported ≥1 fall, but neither total time nor bouts of activity was associated with incident falls (all p > 0.05). CONCLUSION: Higher amounts of accelerometer-determined MVPA are consistently associated with a decreased likelihood of sarcopenia and its components, regardless of the length of bouts or amounts of sedentary behavior.

Falls, fractures, and areal bone mineral density in older adults with sarcopenic obesity: A systematic review and meta-analysis.

Sarcopenia and obesity are common conditions in older adults that may have differing effects on falls and fracture risk. This systematic review and meta-analysis aimed to determine whether older adults with sarcopenic obesity have increased risk of falls and fractures or lower bone mass compared with older adults with sarcopenia, obesity, or neither condition. Twenty-six studies (n = 37,124) were included in the systematic review and 17 (n = 31,540) were included in the meta-analysis. Older adults with sarcopenic obesity had lower femoral neck areal bone mineral density (aBMD) compared with those with obesity alone but had higher femoral neck aBMD compared with counterparts with sarcopenia alone (both P < 0.05). Older adults with sarcopenic obesity had higher nonvertebral fracture rates (incidence rate ratio: 1.88; 95% confidence intervals: 1.09, 3.23; based on two studies), compared with those with sarcopenia alone, and also had higher falls risk compared with controls (risk ratio: 1.30; 95% confidence intervals: 1.10, 1.54) and obesity alone (risk ratio: 1.17; 95% confidence intervals: 1.01, 1.36). In conclusion, this systematic review and meta-analysis has demonstrated that older adults with sarcopenic obesity are at increased risk of adverse musculoskeletal outcomes compared with individuals with obesity, sarcopenia, or neither condition. These data support the need for developing interventions to improve bone health and physical function in this population.

Impact of Protein Intake in Older Adults with Sarcopenia and Obesity: A Gut Microbiota Perspective.

The continuous population increase of older adults with metabolic diseases may contribute to increased prevalence of sarcopenia and obesity and requires advocacy of optimal nutrition treatments to combat their deleterious outcomes. Sarcopenic obesity, characterized by age-induced skeletal-muscle atrophy and increased adiposity, may accelerate functional decline and increase the risk of disability and mortality. In this review, we explore the influence of dietary protein on the gut microbiome and its impact on sarcopenia and obesity. Given the associations between red meat proteins and altered gut microbiota, a combination of plant and animal-based proteins are deemed favorable for gut microbiota eubiosis and muscle-protein synthesis. Additionally, high-protein diets with elevated essential amino-acid concentrations, alongside increased dietary fiber intake, may promote gut microbiota eubiosis, given the metabolic effects derived from short-chain fatty-acid and branched-chain fatty-acid production. In conclusion, a greater abundance of specific gut bacteria associated with increased satiation, protein synthesis, and overall metabolic health may be driven by protein and fiber consumption. This could counteract the development of sarcopenia and obesity and, therefore, represent a novel approach for dietary recommendations based on the gut microbiota profile. However, more human trials utilizing advanced metabolomic techniques to investigate the microbiome and its relationship with macronutrient intake, especially protein, are warranted.

Incidence and predictors of fractures in older adults with and without obesity defined by body mass index versus body fat percentage.

PURPOSE: The aim of this study was to determine and compare risk factors associated with incident fractures in older adults with and without obesity, defined by both body mass index (BMI) and body fat percentage. METHODS: 1,099 older adults (mean ± standard deviation age = 63.0 ± 7.5) years, participated in this prospective cohort study. Obesity status at baseline was defined by BMI (≥30 kg/m2) obtained by anthropometry and body fat percentage (≥30% for men and ≥40% for women) assessed by dual-energy X-ray absorptiometry (DXA). Total hip and lumbar spine areal bone mineral density (aBMD) were assessed by DXA up to five years. Incident fractures were self-reported up to 10 years. RESULTS: Prevalence of obesity was 28% according to BMI and 43% according to body fat percentage. Obese older adults by BMI, but not body fat percentage, had significantly higher aBMD at the total hip and spine compared with non-obese (both p-value<0.05). Obese older adults by body fat percentage had significantly higher likelihood of all incident fractures (OR: 1.71; CI:1.08, 2.71) and non-vertebral fractures (OR: 1.88; CI:1.16, 3.04) compared with non-obese after adjusting for confounders. Conversely, obese older adults by BMI had a significantly lower likelihood (OR: 0.54; CI:0.31, 0.94) of non-vertebral fractures although this was no longer significant after adjustment for total hip aBMD (all p-value > 0.05). Mediation analysis confirmed that aBMD meditated the effects of BMI, but not body fat percentage, on all incident fractures. Higher baseline falls risk score was the only consistent predictor of increased likelihood of incident fracture in obese individuals only, according to both BMI and body fat percentage (both p-value<0.05). CONCLUSIONS: Obesity defined by body fat percentage is associated with increased likelihood of incident fractures in community-dwelling older adults, whereas those who are obese according to BMI have reduced likelihood of incident fracture which appears to be explained by higher aBMD. Falls risk assessment may improve identification of obese older adults at increased risk of incident fractures.

Associations of Health-Related Quality of Life, Fear of Falling and Objective Measures of Physical Function with Bone Health in Postmenopausal Women with Low Bone Mass.

Health-related quality of life (HRQoL) and physical function deteriorate with age and may adversely impact bone health in older adults. We determined associations of objective measures of physical function and HRQoL with bone health in postmenopausal women with low areal bone mineral density (aBMD). Fifty postmenopausal women (64.4 7.7 years old, mean standard deviation) with low spine, hip or femoral neck aBMD (T- or Z-score < -1.0) on dual-energy X-ray absorptiometry (DXA) participated. Femoral surface BMD, trabecular, integral and cortical volumetric BMD (vBMD) measurements were obtained using 3D-SHAPER software on DXA. Distal tibial vBMD and microarchitecture were assessed using high-resolution peripheral quantitative computed tomography (HRpQCT). Participants completed self-administered EuroQol-5D (EQ-5D) and modified falls efficacy scale (MFES) questionnaires, and physical function assessments. Stair climb power was positively associated with bone parameters at the hip, femoral neck, and distal tibia (all p < 0.05) in multivariable linear regression. EQ-5D demonstrated no significant associations with bone parameters and MFES was positively associated only with distal tibial cortical vBMD and cortical von Mises stress (both p < 0.05). Objective measures of physical function, particularly muscle power, are more consistently associated with bone parameters compared with self-administered HRQoL questionnaires.