Search

OBJECTIVE: To evaluate the associations between definitions of sarcopenia and clinical outcomes and the ability of the definitions to discriminate those with a high likelihood of having these outcomes from those with a low likelihood. DESIGN: Osteoporotic Fractures in Men Study. SETTING: Six clinical centers. PARTICIPANTS: Community-dwelling men aged 65 and older (N = 5,934). MEASUREMENTS: Sarcopenia definitions from the International Working Group, European Working Group on Sarcopenia in Older Persons, Foundation for the National Institutes of Health Sarcopenia Project, Baumgartner, and Newman were evaluated. Recurrent falls were defined as two or more self-reported falls in the year after baseline (n = 694, 11.9%). Incident hip fractures (n = 207, 3.5%) and deaths (n = 2,003, 34.1%) were confirmed according to central review of medical records over 9.8 years. Self-reported functional limitations were assessed at baseline and 4.6 years later. Logistic regression or proportional hazards models were used to estimate associations between sarcopenia and falls, hip fractures, and death. The discriminative ability of the sarcopenia definitions (vs reference models) for these outcomes was evaluated using area under the receiver operating characteristic curve or C-statistics. Referent models included age alone for falls, functional limitations and mortality, and age and bone mineral density for hip fractures. RESULTS: The association between sarcopenia according to the various definitions and risk of falls, functional limitations, and hip fractures was variable; all definitions were associated with greater risk of death, but none of the definitions materially changed discrimination based on the AUC and C-statistic when compared with reference models (change <1% in all models). CONCLUSION: Sarcopenia definitions as currently constructed did not consistently improve prediction of clinical outcomes in relatively healthy older men. [ABSTRACT FROM AUTHOR]

Objectives To determine whether older women with diabetes mellitus have a greater longitudinal decline in physical performance than those without and whether any decline differs according to insulin sensitizer use. Design Prospective cohort study. Setting Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; and the Monongahela, Pennsylvania. Participants Community-dwelling women (mean age 78.5 ± 3.6) enrolled in the Study of Osteoporotic Fractures in 1997-98 and restudied 4.9 ± 0.6 years later (N = 2,864). Measurements Women were categorized as having no diabetes mellitus (n = 2,680) or having diabetes mellitus (n = 184). A prescription medication inventory was used to determine use of insulin sensitizers (metformin and thiazolidinedione). The outcomes were longitudinal changes in physical performance measures, including grip strength, usual walk speed, and rapid walk speed. Results Estimates from fully adjusted models showed that women with diabetes mellitus had greater declines in usual walk speed (−0.16 m/s, 95% confidence interval ( CI) = −0.19 to −0.14) and rapid walk speed (−0.21 m/s, 95% CI = −0.24 to −0.17) than those without (usual walk speed −0.11 m/s, 95% CI = −0.12 to −0.11, P < .001; rapid walk speed −0.15 m/s, 95% CI = −0.16 to −0.14; P = .005). Women with diabetes mellitus taking insulin sensitizers had less decline in usual walk speed than those not taking insulin sensitizers ( P < .001). Declines in grip strength did not differ significantly by diabetes mellitus status or insulin sensitizer use. Conclusion Older women with diabetes mellitus have a greater decline in walk speed, but not grip strength, than older women without diabetes mellitus. Clinical studies in older adults to determine whether diabetes mellitus treatments such as insulin sensitizers can prevent loss in walk speed and mobility are needed. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To examine the associations between insulin resistance and changes in body composition in older men without diabetes mellitus. DESIGN: Longitudinal cohort study of older men participating in the Osteoporotic Fractures in Men (MrOS) study. SETTING: Six U.S. clinical centers. PARTICIPANTS: Three thousand one hundred thirty-two ambulatory men aged 65 and older at baseline. MEASUREMENTS: Baseline insulin resistance was calculated for men without diabetes mellitus using the homeostasis model assessment of insulin resistance (HOMA-IR). Total lean, appendicular lean, total fat, and truncal fat mass were measured using dual energy X-ray absorptiometry scans at baseline and 4.6 ±0.3 years later in 3,132 men with HOMA-IR measurements. RESULTS: There was greater loss of weight, total lean mass, and appendicular lean mass and less gain in total fat mass and truncal fat mass with increasing quartiles of HOMA-IR (P<.001 for trend). Insulin-resistant men in the highest quartile had higher odds of 5% or more loss of weight (odds ratio (OR)=1.88, 95% confidence interval (CI)=1.46–2.43), total lean mass (OR=2.09, 95% CI=1.60–2.73) and appendicular lean mass (OR=1.57, 95% CI=1.27–1.95) and lower odds of 5% or more gain in total fat mass (OR=0.56, 95% CI=0.45–0.68) and truncal fat mass (OR=0.52, 95% CI=0.42–0.64) than those in the lowest quartile. These findings remained significant after accounting for age, site, baseline weight, physical activity, and change in physical activity. These associations were also independent of other metabolic syndrome features and medications. CONCLUSION: Greater lean mass loss and lower fat mass gain occurred in insulin-resistant men without diabetes mellitus than in insulin-sensitive men. Insulin resistance may accelerate age-related sarcopenia. [ABSTRACT FROM AUTHOR]

To evaluate risk of all-cause mortality associated with changes in body weight, total lean mass, and total fat mass in older men. Longitudinal cohort study. Six U.S. clinical centers. Four thousand three hundred thirty-one ambulatory men aged 65 to 93 at baseline. Repeated measurements of body weight and total lean and fat mass were taken using dual-energy X-ray absorptiometry 4.6 ± 0.4 years apart. Percentage changes in these measures were categorized as gain (+5%), loss (-5%), or stable (−5% to +5%). Deaths were verified centrally according to death certificate reviews, and proportional hazard models were used to estimate the risk of mortality. After accounting for baseline lifestyle factors and medical conditions, a higher risk of mortality was found for men with weight loss (hazard rat (HR)=1.84, 95% confidence interval (CI)=1.50-2.26), total lean mass loss (HR=1.78, 95% CI=1.45-2.19), and total fat mass loss (HR=1.72, 95% CI=1.34-2.20) than for men who were stable for each body composition measure. Men with total fat mass gain had a slightly greater mortality risk (HR=1.29, 95% CI=0.99-1.67) than those who remained stable. These associations did not differ according to baseline age, obesity, or self-reported health status ( P for interactions >.10), although self-reported weight loss intent altered mortality risks with total fat mass ( P for interaction=.04) and total lean mass ( P for interaction=.09) change. Older men who lost weight, total lean mass, or total fat mass had a higher risk of mortality than men who remained stable. [ABSTRACT FROM AUTHOR]