Sarcopenia definition & outcomes consortium defined low grip strength in two cross-sectional, population-based cohorts

Authors: PATEL, SHEENA - California Pacific Medical Center Research Institute; DUCHOWNY, KATE - California Pacific Medical Center Research Institute; KIEL, DOUGLAS - Hebrew Senior Life; CORREA-DE-ARAUJO, ROSALY - National Institute On Aging (NIA, NIH); FIELDING, ROGER - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; TRAVISON, THOMAS - Hebrew Senior Life; MAGAZINER, JAY - University Of Maryland; MANINI, TODD - University Of Florida; XUE, QIAN-LI - Johns Hopkins University; NEWMAN, ANNE - University Of Pittsburgh; PENCINA, KAROL - Harvard University; SANTANASTO, ADAM - University Of Pittsburgh; BHASIN, SHALENDAR - Harvard University; CAWTHON, PEGGY - California Pacific Medical Center Research Institute

Submitted to: Journal of the American Geriatrics Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2020
Publication Date: 7/7/2020
Citation: Patel, S.M., Duchowny, K.A., Kiel, D.P., Correa-de-Araujo, R., Fielding, R.A., Travison, T., Magaziner, J., Manini, T., Xue, Q., Newman, A.B., Pencina, K.M., Santanasto, A., Bhasin, S., Cawthon, P.M. 2020. Sarcopenia definition & outcomes consortium defined low grip strength in two cross-sectional, population-based cohorts. Journal of the American Geriatrics Society. https://doi.org/10.1111/jgs.16419.
DOI: https://doi.org/10.1111/jgs.16419

Interpretive Summary: For the first time, the extent to which the prevalence of muscle weakness using a measure of handgrip strength in the United States population varies has been described by the Sarcopenia Definitions and Outcomes Consortium (SDOC). Using two nationally representative studies: Health and Retirement Survey and the National Health and Aging Trends Survey, investigators studied 12,984 adults aged 65 and older. We analyzed three different measures of muscle weakness developed by the SDOC and found absolute grip strength, grip strength standardized to body mass index, and grip strength standardized to body weight, respectively, to be associated with mobility disability for men and women. We estimated the prevalence of muscle weakness defined by each of these individual measures in the overall older U.S. population, and by age, sex, race and ethnicity. The prevalence of muscle weakness ranged from 23-61% for men and 30-66% for women depending on the measure of grip strength used. There was substantial variation in the prevalence of muscle weakness by race and ethnicity. The prevalence of muscle weakness, defined by the SDOC grip strength cut-points, varies depending on the measure selected. These values have significance for evaluating muscle weakness in older adults.

Technical Abstract: BACKGROUND/OBJECTIVES: The extent to which the prevalence of muscle weakness in the US population varies by different putative grip strength constructs developed by the Sarcopenia Definitions and Outcomes Consortium (SDOC) has not been described. DESIGN: Cross-sectional analysis. SETTING: Two nationally representative cohorts-2010 and 2012 waves of the Health and Retirement Survey and round 1 (2011) of the National Health and Aging Trends Survey. PARTICIPANTS: Adults aged 65 years and older (n = 12,984) were included in these analyses. MEASUREMENTS: We analyzed three constructs of muscle weakness developed by the SDOC, and found to be associated with mobility disability for men and women, respectively: absolute grip strength (<35.5 kg and 20 kg); grip strength standardized to body mass index (<1.05 kg/kg/m2 and 0.79 kg/kg/m2); and grip strength standardized to weight (<0.45 kg/kg and 0.337 kg/kg). We estimated the prevalence of muscle weakness defined by each of these constructs in the overall older US population, and by age, sex, race, and ethnicity. We also estimated the sensitivity and specificity of each of the grip strength constructs to discriminate slowness (gait speed <0.8 m/s) in these samples. RESULTS: The prevalence of muscle weakness ranged from 23% to 61% for men and from 30% to 66% for women, depending on the construct used. There was substantial variation in the prevalence of muscle weakness by race and ethnicity. The sensitivity and specificity of these measures for discriminating slowness varied widely, ranging from 0.30 to 0.92 (sensitivity) and from 0.17 to 0.88 (specificity). CONCLUSIONS: The prevalence of muscle weakness, defined by the putative SDOC grip strength constructs, depends on the construct of weakness used.