Putative cut-points in sarcopenia components and incident adverse health outcomes: an SDOC analysis

Authors: CAWTHON, PEGGY - CALIFORNIA PACIFIC MEDICAL CENTER RESEARCH INSTITUTE; MANINI, TODD - UNIVERSITY OF FLORIDA; PATEL, SHEENA - CALIFORNIA PACIFIC MEDICAL CENTER RESEARCH INSTITUTE; NEWMAN, ANNE - UNIVERSITY OF PITTSBURGH; TRAVISON, THOMAS - HEBREW SENIOR LIFE; KIEL, DOUGLAS - HEBREW SENIOR LIFE; SANTANASTO, ADAM - UNIVERSITY OF PITTSBURGH; ENSRUD, KRISTINE - UNIVERSITY OF MINNESOTA; XUE, QIAN-LI - JOHNS HOPKINS UNIVERSITY SCHOOL OF MEDICINE; SHARDELL, MICHELLE - NATIONAL INSTITUTE ON AGING (NIA, NIH); DUCHOWNY, KATE - UNIVERSITY OF CALIFORNIA; ERLANDSON, KRISTINE - UNIVERSITY OF COLORADO; PENCINA, KAROL - UNIVERSITY OF PITTSBURGH; FIELDING, ROGER - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY; MAGAZINER, JAY - UNIVERSITY OF MARYLAND; KWOK, TIMOTHY - THE CHINESE UNIVERSITY OF HONG KONG (CUHK); KARLSSON, MAGNUS - LUND UNIVERSITY; OHLSSON, CLAES - UNIVERSITY OF GOTHENBURG; MELLSTROM, DAN - UNIVERSITY OF GOTHENBURG; HIRANI, VASANT - UNIVERSITY OF SYDNEY; RIBOM, EVA - UPPSALA UNIVERSITY; CORREA-DE-ARAUJO, ROSALY - NATIONAL INSTITUTE ON AGING (NIA, NIH); BHASIN, SHALENDER - HARVARD UNIVERSITY

Submitted to: Journal of the American Geriatrics Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2020
Publication Date: 7/7/2020
Citation: Cawthon, P.M., Manini, T., Patel, S.M., Newman, A., Travison, T., Kiel, D.P., Santanasto, A.J., Ensrud, K.E., Xue, Q., Shardell, M., Duchowny, K., Erlandson, K.M., Pencina, K.M., Fielding, R.A., Magaziner, J., Kwok, T., Karlsson, M., Ohlsson, C., Mellstrom, D., Hirani, V., Ribom, E., Correa-De-Araujo, R., Bhasin, S. 2020. Putative cut-points in sarcopenia components and incident adverse health outcomes: an SDOC analysis. Journal of the American Geriatrics Society. 68:1429-1437. https://doi.org/10.1111/jgs.16517.
DOI: https://doi.org/10.1111/jgs.16517

Interpretive Summary: Analyses performed by the Sarcopenia Definitions and Outcomes Consortium (SDOC) identified cut-points for measure of muscle weakness using handgrip strength for consideration in a definition of sarcopenia. This paper describes the possible measures of sarcopenia including muscle weakness by handgrip strength, low muscle mass (another possible measure of sarcopenia), and slow walking speed (less than 0.8 meters per second) and their relationship to well documented adverse clinical outcomes (eg: falls, hip fractures, mobility limitation, mortality(death)). Using 8 prospective observational cohort studies with 13,421 older men and 4,828 women, we found that low handgrip strength was associated with falls, hip fractures, mobility limitation, and mortality (death). These association appeared to be independent of whether people walked slowly or not. Our measure of muscle mass was not consistently associated with falls, hip fractures, mobility limitation, or mortality (death). When considered together, those participants who had both muscle weakness and walked slowly were more likely to have a fall, hip fracture, mobility limitation or die than those without either slowness or muscle weakness. These results support the inclusion of grip strength and slow walking speed as components in a summary definition of sarcopenia.

Technical Abstract: OBJECTIVES: Analyses performed by the Sarcopenia Definitions and Outcomes Consortium (SDOC) identified cutpoints in several metrics of grip strength for consideration in a definition of sarcopenia. We describe the associations between the SDOC-identified metrics of low grip strength (absolute or standardized to body size/composition); low dual-energy x-ray absorptiometry (DXA) lean mass as previously defined in the literature (appendicular lean mass [ALM]/ht2); and slowness (walking speed <.8 m/s) with subsequent adverse outcomes (falls, hip fractures, mobility limitation, and mortality). DESIGN: Individual-level, sex-stratified pooled analysis. We calculated odds ratios (ORs) or hazard ratios (HRs) for incident falls, mobility limitation, hip fractures, and mortality. Follow-up time ranged from 1 year for falls to 8.8 +/- 2.3 years for mortality. SETTING: Eight prospective observational cohort studies. PARTICIPANTS: A total of 13,421 community-dwelling men and 4,828 community-dwelling women. MEASUREMENTS: Grip strength by hand dynamometry, gait speed, and lean mass by DXA. RESULTS: Low grip strength (absolute or standardized to body size/composition) was associated with incident outcomes, usually independently of slowness, in both men and women. ORs and HRs generally ranged from 1.2 to 3.0 for those below vs above the cut-point. DXA lean mass was not consistently associated with these outcomes. When considered together, those who had both muscle weakness by absolute grip strength (<35.5 kg in men and <20 kg in women) and slowness were consistently more likely to have a fall, hip fracture, mobility limitation, or die than those without either slowness or muscle weakness. CONCLUSION: Older men and women with both muscle weakness and slowness have a higher likelihood of adverse health outcomes. These results support the inclusion of grip strength and walking speed as components in a summary definition of sarcopenia.