Greater pQCT calf muscle density is associated with lower fracture risk, independent of FRAX, falls and BMD: a meta-analysis in the osteoporotic fractures in men (MrOS) study

We investigated the predictive performance of peripheral quantitative computed tomography (pQCT) measures of both calf muscle density (an established surrogate for muscle adiposity, with higher values indicating lower muscle adiposity and higher muscle quality) and size (cross-sectional area [CSA]) for incident fracture. pQCT (Stratec XCT2000/3000) measurements at the tibia were undertaken in Osteoporotic Fractures in Men (MrOS) United States (US), Hong Kong (HK), and Swedish (SW) cohorts. Analyses were by cohort and synthesized by meta-analysis. The predictive value for incident fracture outcomes, illustrated here for hip fracture (HF), using an extension of Poisson regression adjusted for age and follow-up time, was expressed as hazard ratio (HR) per standard deviation (SD) increase in exposure (HR/SD). Further analyses adjusted for femoral neck (fn) bone mineral density (BMD) T-score, Fracture Risk Assessment Tool (FRAX) 10-year fracture probability (major osteoporotic fracture) and prior falls. We studied 991 (US), 1662 (HK), and 1521 (SW) men, mean ± SD age 77.0 ± 5.1, 73.9 ± 4.9, 80 ± 3.4 years, followed for a mean ± SD 7.8 ± 2.2, 8.1 ± 2.3, 5.3 ± 2.0 years, with 31, 47, and 78 incident HFs, respectively. Both greater muscle CSA and greater muscle density were associated with a lower risk of incident HF [HR/SD: 0.84; 95% confidence interval [CI], 0.72–1.0 and 0.78; 95% CI, 0.66–0.91, respectively]. The pattern of associations was not materially changed by adjustment for prior falls or FRAX probability. In contrast, after inclusion of fn BMD T-score, the association for muscle CSA was no longer apparent (1.04; 95% CI, 0.88–1.24), whereas that for muscle density was not materially changed (0.69; 95% CI, 0.59–0.82). Findings were similar for osteoporotic fractures. pQCT measures of greater calf muscle density and CSA were both associated with lower incidence of fractures in older men, but only muscle density remained an independent risk factor for fracture after accounting for fn BMD. These findings demonstrate a complex interplay between measures of bone, muscle size, and quality, in determining fracture risk. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

Determinants of Change in Objectively Assessed Sleep Duration among Older Men

10.1093/aje/kwx014American Journal of Epidemiology18510933-94

A higher protein intake is not associated with 5-year change in mid-thigh muscle cross-sectional area by computed tomography in older adults: the health, aging, and body composition (Health ABC) study

Rationale: A higher protein intake is suggested to preserve muscle mass during aging, and may therefore reduce the risk for sarcopenia. We explored whether the amount, type (animal/vegetable) and essential amino acid (EAA) composition of protein intake were associated with 5-year change in mid-thigh muscle cross-sectional area (CSA) in older adults. Methods: Protein intake was assessed at year 2 by a Block food frequency questionnaire in 2,597 participants of the Health ABC study, aged 70–79 y. At year 1 and year 6 mid-thigh muscle CSA (cm2) was measured by computed tomography. Multiple linear regression analysis was used to examine the association between energy adjusted protein residuals (total, animal and vegetable protein) and muscle CSA at year 6, adjusted for muscle CSA at year 1 and potential confounders including prevalent health conditions, physical activity and 5-year change in fat mass. EAA intake was expressed as percentage of total protein intake. Results: Mean protein intake was 0.90 (SD 0.36) g/kg/d and mean 5-year change in muscle CSA was −9.8 (17.0) cm2 (n = 1,561). No association was observed between energy adjusted total (β = −0.00 cm2 ; SE = 0.03; P = 0.98), animal (β = −0.00 cm2; SE = 0.03; P = 0.92), and plant (β = +0.07 cm2; SE = 0.07; P = 0.291) protein intake and muscle CSA at year 6, adjusted for baseline mid-thigh muscle area and potential confounders. No associations were observed for the EAAs. Conclusion: A higher total, animal or vegetable protein intake was not associated with 5 year change in mid-thigh cross sectional area in older adults. This conclusion contradicts some, but not all previous research, therefore optimal protein intake for older adults is currently not known

Transition to Sarcopenia and Determinants of Transitions in Older Adults: A Population-Based Study

Background. Diagnostic criteria for sarcopenia from appendicular lean mass (ALM), strength, and performance have been proposed, but little is known regarding the progression of sarcopenia. We examined the time course of sarcopenia and determinants of transitioning toward and away from sarcopenia. Methods. ALM, gait speed, and grip strength were assessed seven times over 9 years in 2,928 initially well-functioning adults aged 70-79. Low ALM was defined as less than 7.95 kg/

Comparison of 2 frailty indexes for prediction of falls, disability, fractures, and death in older women.

BACKGROUND: Frailty, as defined by the index derived from the Cardiovascular Health Study (CHS index), predicts risk of adverse outcomes in older adults. Use of this index, however, is impractical in clinical practice. METHODS: We conducted a prospective cohort study in 6701 women 69 years or older to compare the predictive validity of a simple frailty index with the components of weight loss, inability to rise from a chair 5 times without using arms, and reduced energy level (Study of Osteoporotic Fractures [SOF index]) with that of the CHS index with the components of unintentional weight loss, poor grip strength, reduced energy level, slow walking speed, and low level of physical activity. Women were classified as robust, of intermediate status, or frail using each index. Falls were reported every 4 months for 1 year. Disability (> or =1 new impairment in performing instrumental activities of daily living) was ascertained at 4(1/2) years, and fractures and deaths were ascertained during 9 years of follow-up. Area under the curve (AUC) statistics from receiver operating characteristic curve analysis and -2 log likelihood statistics were compared for models containing the CHS index vs the SOF index. RESULTS: Increasing evidence of frailty as defined by either the CHS index or the SOF index was similarly associated with an increased risk of adverse outcomes. Frail women had a higher age-adjusted risk of recurrent falls (odds ratio, 2.4), disability (odds ratio, 2.2-2.8), nonspine fracture (hazard ratio, 1.4-1.5), hip fracture (hazard ratio, 1.7-1.8), and death (hazard ratio, 2.4-2.7) (P < .001 for all models). The AUC comparisons revealed no differences between models with the CHS index vs the SOF index in discriminating falls (AUC = 0.61 for both models; P = .66), disability (AUC = 0.64; P = .23), nonspine fracture (AUC = 0.55; P = .80), hip fracture (AUC = 0.63; P = .64), or death (AUC = 0.72; P = .10). Results were similar when -2 log likelihood statistics were compared. CONCLUSION: The simple SOF index predicts risk of falls, disability, fracture, and death as well as the more complex CHS index and may provide a useful definition of frailty to identify older women at risk of adverse health outcomes in clinical practice

Weight Change, Body Composition, and Risk of Mobility Disability and Mortality in Older Adults: a Population-Based Cohort Study

OBJECTIVES: To examine associations between weight change, body composition, risk of mobility disability, and mortality in older adults. DESIGN: Prospective, longitudinal, population-based cohort. SETTING: The Health, Aging, and Body Composition Study. PARTICIPANTS: Women (n = 1,044) and men (n = 931) aged 70 to 79. MEASUREMENTS: Weight and lean and fat mass from dual-energy X-ray absorptiometry measured annually over 5 years. Weight was defined as stable (n = 664, reference), loss (n = 662), gain (n = 321), or cycling (gain and loss, n = 328) using change of 5% from year to year or from Year 1 to 6. Mobility disability (two consecutive reports of difficulty walking one-quarter mile or climbing 10 steps) and mortality were determined for 8 years after the weight change period. Associations were analyzed using Cox proportional hazards regression adjusted for covariates. RESULTS: During follow-up, 313 women and 375 men developed mobility disability, and 322 women and 378 men died. There was no risk of mobility disability or mortality with weight gain. Weight loss (hazard ratio (HR) = 1.88, 95% confidence interval (CI) = 1.40-2.53) and weight cycling (HR = 1.59, 95% CI = 1.11-2.29) were associated with mobility disability in women, and weight loss was associated with mobility disability in men (HR = 1.30, 95% CI = 1.01-1.69). Weight loss and weight cycling were associated with mortality risk in women (weight loss: HR = 1.47, 95% CI = 1.07-2.01; weight cycling: HR = 1.62, 95% CI = 1.15-2.30) and in men (weight loss: HR = 1.41, 95% CI = 1.09-1.83; weight cycling: HR = 1.50, 95% CI = 1.08-2.08). Adjustment for lean and fat mass and change in lean and fat mass from Year 1 to 6 attenuated the relationships between weight loss and mobility disability in men and between weight loss and mortality in men and women. CONCLUSION: Weight cycling and weight loss predict impending mobility disability and mortality in old age, underscoring the prognostic importance of weight history

Predicting slow walking speed from a pooled cohort analysis: sarcopenia definitions, agreement and prevalence in Australia and New Zealand

OnlinePublBackground: Recent operational definitions of sarcopenia have not been replicated and compared in Australia and New Zealand (ANZ) populations. We aimed to identify sarcopenia measures that discriminate ANZ adults with slow walking speed (<0.8 m/s) and determine the agreement between the Sarcopenia Definitions and Outcomes Consortium (SDOC) and revised European Working Group for Sarcopenia in Older People (EWGSOP2) operational definitions of sarcopenia. Methods: Eight studies comprising 8 100 ANZ community-dwelling adults (mean age ± standard deviation, 62.0 ± 14.4 years) with walking speed, grip strength (GR), and lean mass data were combined. Replicating the SDOC methodology, 15 candidate variables were included in sex-stratified classification and regression tree models and receiver operating characteristic curves on a pooled cohort with complete data to identify variables and cut points discriminating slow walking speed (<0.8 m/s). Agreement and prevalence estimates were compared using Cohen’s Kappa (CK). Results: Receiver operating characteristic curves identified GR as the strongest variable for discriminating slow from normal walking speed in women (GR <20.50 kg, area under curve [AUC] = 0.68) and men (GR <31.05 kg, AUC = 0.64). Near-perfect agreement was found between the derived ANZ cut points and SDOC cut points (CK 0.8–1.0). Sarcopenia prevalence ranged from 1.5% (EWGSOP2) to 37.2% (SDOC) in women and 1.0% (EWGSOP2) to 9.1% (SDOC) in men, with no agreement (CK <0.2) between EWGSOP2 and SDOC. Conclusions: Grip strength is the primary discriminating characteristic for slow walking speed in ANZ women and men, consistent with findings from the SDOC. Sarcopenia Definitions and Outcomes Consortium and EWGSOP2 definitions showed no agreement suggesting these proposed definitions measure different characteristics and identify people with sarcopenia differently.Jesse Zanker, David Scott, Cassandra Szoeke, Sara Vogrin, Sheena Patel, Terri Blackwell, Stefanie Bird, Ben Kirk, Jacqueline Center, Dima A. Alajlouni, Tiffany Gill, Graeme Jones, Julie A. Pasco, Debra L. Waters, Peggy M. Cawthon, and Gustavo Duqu

Sarcopenia definitions as predictors of fracture risk independent of FRAX®, falls, and BMD in the osteoporotic fractures in men (MrOS) study: a meta‐analysis

Dual‐energy X‐ray absorptiometry (DXA)‐derived appendicular lean mass/height2 (ALM/ht2) is the most commonly used estimate of muscle mass in the assessment of sarcopenia, but its predictive value for fracture is substantially attenuated by femoral neck (fn) bone mineral density (BMD). We investigated predictive value of 11 sarcopenia definitions for incident fracture, independent of fnBMD, fracture risk assessment tool (FRAX®) probability, and prior falls, using an extension of Poisson regression in US, Sweden, and Hong Kong Osteoporois Fractures in Men Study (MrOS) cohorts. Definitions tested were those of Baumgartner and Delmonico (ALM/ht2 only), Morley, the International Working Group on Sarcopenia, European Working Group on Sarcopenia in Older People (EWGSOP1 and 2), Asian Working Group on Sarcopenia, Foundation for the National Institutes of Health (FNIH) 1 and 2 (using ALM/body mass index [BMI], incorporating muscle strength and/or physical performance measures plus ALM/ht2), and Sarcopenia Definitions and Outcomes Consortium (gait speed and grip strength). Associations were adjusted for age and time since baseline and reported as hazard ratio (HR) for first incident fracture, here major osteoporotic fracture (MOF; clinical vertebral, hip, distal forearm, proximal humerus). Further analyses adjusted additionally for FRAX‐MOF probability (n = 7531; calculated ± fnBMD), prior falls (y/n), or fnBMD T‐score. Results were synthesized by meta‐analysis. In 5660 men in USA, 2764 Sweden and 1987 Hong Kong (mean ages 73.5, 75.4, and 72.4 years, respectively), sarcopenia prevalence ranged from 0.5% to 35%. Sarcopenia status, by all definitions except those of FNIH, was associated with incident MOF (HR = 1.39 to 2.07). Associations were robust to adjustment for prior falls or FRAX probability (without fnBMD); adjustment for fnBMD T‐score attenuated associations. EWGSOP2 severe sarcopenia (incorporating chair stand time, gait speed, and grip strength plus ALM) was most predictive, albeit at low prevalence, and appeared only modestly influenced by inclusion of fnBMD. In conclusion, the predictive value for fracture of sarcopenia definitions based on ALM is reduced by adjustment for fnBMD but strengthened by additional inclusion of physical performance measures