Application of SDOC cut points for low muscle strength for recovery of walking speed after hip fracture

Authors: ORWIG, DENISE - University Of Maryland; MAGAZINER, JAY - University Of Maryland; FIELDING, ROGER - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; ZHU, HAO - Hebrew Senior Life; BINDER, ELLEN - Washington University; CAWTHON, PEGGY - California Pacific Medical Center Research Institute; BHASIN, SHALENDER - Brigham & Women'S Hospital; CORREA-DE-ARAUJO, ROSALY - National Institute On Aging (NIA, NIH); MANINI, TODD - University Of Florida; PATEL, SHEENA - California Pacific Medical Center Research Institute; SHARDELL, MICHELLE - National Institute On Aging (NIA, NIH); TRAVISON, THOMAS - Harvard University

Submitted to: Journal of Gerontology Medical Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2020
Publication Date: 4/3/2020
Citation: Orwig, D., Magaziner, J., Fielding, R.A., Zhu, H., Binder, E.F., Cawthon, P., Bhasin, S., Correa-De-Araujo, R., Manini, T., Patel, S., Shardell, M., Travison, T.G. 2020. Application of SDOC cut points for low muscle strength for recovery of walking speed after hip fracture. Journal of Gerontology Medical Science. 75(7):1379-1385. https://doi.org/10.1093/gerona/glaa076.
DOI: https://doi.org/10.1093/gerona/glaa076

Interpretive Summary: Sarcopenia is often considered to occur before the loss of mobility, but the role of sarcopenia status on the recovery of mobility after a hip fracture is unknown. We determined the prevalence of low muscle strength (weakness) after hip fracture using meaures of sarcopenia (absolute grip strength, and grip strength normalized to body mass index, total body fat, arm lean mass, and weight) identified by the Sarcopenia Definitions and Outcomes Consortium (SDOC). Using two well-characterized hip fracture cohorts of community-dwelling older adults from the Baltimore Hip Studies, we found that at two months, 91% women and 78% men exhibited slow walking speed. Grip strength standardized by body weight was the most prevalent measure of weakness in men and women and predicted lack of meaningful change (no improvement) in walking speed at six months. The SDOC cut-points for grip strength standardized to weight provided consistent indication of poor walking speed performance following a hip fracture in older adults.

Technical Abstract: BACKGROUND: Sarcopenia is often conceptualized as a precursor to loss of mobility, but its effect on recovery of mobility after a hip fracture is unknown. We determined the prevalence of low muscle strength (weakness) after hip fracture using putative sarcopenia metrics (absolute grip strength, and grip strength normalized to body mass index, total body fat, arm lean mass, and weight) identified by the Sarcopenia Definitions and Outcomes Consortium (SDOC). METHODS: We examined two well-characterized hip fracture cohorts of community-dwelling older adults from the Baltimore Hip Studies (BHS). The prevalence of muscle weakness was assessed using the SDOC cut-points compared to published definitions at two and six months post-fracture. We assessed associations of two-month weakness with 6-month walking speed <0.6 m/s and calculated the sensitivity and specificity in predicting lack of meaningful change in walking speed (change < 0.1 m/s) at six months. RESULTS: 246 participants (192 women; 54 men) were included; mean (SD) age of 81(8) for women and 78 (7) for men. At two months, 91% women and 78% men exhibited slow walking speed (< 0.6 m/s). SDOC grip strength standardized by weight (<0.34 kg women, <0.45 kg men) was the most prevalent measure of weakness in men (74%) and women (79%) and provided high sensitivity in men (86%) and women (84%) predicting lack of meaningful change in walking speed at six months, although specificity was poor to moderate. CONCLUSIONS: SDOC cut-points for grip strength standardized to weight provided consistent indication of poor walking speed performance post hip fracture.