Across 8,924 Chinese adults aged 45+ followed for a median of 5.4 years, two distinct grip-strength markers predicted all-cause mortality differently. Persistent low handgrip strength (abnormal at both 2011 and 2013 assessments) carried the highest risk — a 2.35-fold increase in mortality hazard. Even newly developed low grip strength by 2013 raised risk by 91%, and participants who temporarily normalized still faced 54% excess mortality. Persistent handgrip strength asymmetry (imbalance between dominant and non-dominant hands) raised mortality risk by 32%, but only when abnormal at both time points — a weaker and more conditional signal than absolute weakness.
Grip strength has emerged as one of the most practical, low-cost biomarkers of systemic aging, correlating with cardiovascular disease, sarcopenia, and frailty trajectories. This study adds nuance: bilateral imbalance is a real but secondary signal, while absolute weakness — even transiently experienced — leaves a mortality footprint that normalization does not fully erase. That residual risk after normalization suggests grip strength captures cumulative muscle-health history, not just a snapshot. Limitations include the observational design, a single Chinese cohort limiting generalizability, and a relatively short follow-up window. Still, the finding that even recovered low grip strength predicts elevated mortality is clinically meaningful: it supports routine bilateral grip testing from midlife onward and argues against treating a single normal reading as reassuring after prior weakness.
