A commentary published in Aging Clinical and Experimental Research argues that grip strength, widely used as a marker of healthy aging, may not fully capture the functional determinants of successful aging, and that several methodological choices in a recent multi-cohort analysis deserve closer scrutiny.
The piece, authored by Zebo Kudratova and colleagues as a Matters Arising contribution, responds to a study by Zhuang and Gao that examined the prospective association between cumulative average grip strength and successful aging using three international cohorts.
The authors acknowledge that the multi-cohort design offers valuable cross-population insights, but they identify four main concerns. First, they argue that grip strength may not fully represent the functional dimensions of successful aging, noting that lower-extremity measures, such as chair standing tests, have shown stronger predictive validity.
Second, the commentary highlights the use of self-reported chronic disease, which the authors say introduces misclassification bias that can vary across socioeconomic groups. Because reporting accuracy may differ between populations, comparisons across cohorts could be affected by this measurement issue.
Third, the authors question whether the two-stage temporal design of the original study fully addresses selection bias and cross-cohort comparability. They point to heterogeneous exposure windows across the cohorts as a source of comparability problems that the design does not completely resolve.
Fourth, the commentary criticizes the use of a cohort-relative cognitive threshold, arguing that defining cognitive performance relative to each cohort undermines comparability across populations. A threshold set within each cohort may classify different levels of absolute cognitive function as equivalent, complicating cross-national interpretation.
The authors state that addressing these considerations would strengthen future research on successful aging. They frame their contribution as methodological reflection rather than a rejection of the original findings, suggesting directions for improving multi-cohort studies of functional measures and aging outcomes.
The commentary appears in Volume 38 of the journal as article number 210 and was published on 15 October 2026. According to the data availability statement, no datasets were generated or analysed during the study, consistent with its nature as a methodological commentary.
Subject of Research: Methodological critique of using grip strength to study successful aging across three international cohorts
Article Title: Can grip strength capture what chair standing does? methodological considerations on functional measures and successful aging in three international cohorts
Article References: Kudratova, Z., Karabaev, A., Raxmanova, V., Sadikova, A., Axmadjonova, S., & Bagheri, F. V. (2026). Can grip strength capture what chair standing does? methodological considerations on functional measures and successful aging in three international cohorts. Aging Clinical and Experimental Research, 38(1), Article 210. https://doi.org/10.1007/s40520-026-03523-z
Image Credits: AI Generated
DOI: 10.1007/s40520-026-03523-z
Keywords: grip strength, successful aging, chair standing, functional measures, cohorts, methodology, population aging, cognitive threshold, selection bias, misclassification bias, grip, strength
