The Association Between Handgrip Strength Asymmetry Severity and Future Morbidity Accumulation: Results from the Health and Retirement Study.

Analyzing the severity of handgrip strength (HGS) asymmetry in aging populations may help to screen for morbidities and add utility to handgrip dynamometer testing. Our study sought to determine the relationships between HGS asymmetry severity and future accumulating morbidities in older Americans. Secondary analyses from the 2006-2016 waves of the Health and Retirement Study included 18,506 adults ≥ 50 years old. The highest recorded HGS values from each hand were used to calculate HGS asymmetry ratio (non-dominant HGS/dominant HGS). If the HGS asymmetry ratio < 1.0, it was inversed to make all asymmetry ratios ≥ 1.0. Participants were categorized into groups based on the severity of their HGS asymmetry ratio: 1) 0.0% - 10.0%, 2) 10.1% - 20.0%, 3) 20.1% - 30.0%, and 4) > 30.0%. Healthcare provider-diagnosed morbidities (hypertension, diabetes, cancer, chronic lung disease, cardiovascular disease, stroke, arthritis, and psychiatric problems) were self-reported. Covariate-adjusted ordinal generalized estimating equations evaluated the relationships between HGS asymmetry severity on future accumulating morbidities. Results showed 8,936 (48.3%) participants had HGS asymmetry 0.0%-10.0%, 6,105 (33.0%) participants had HGS asymmetry 10.1%-20.0%, 2,411 (13.0%) participants had HGS asymmetry 20.1%-30.0%, and 1,054 (5.7%) participants had HGS asymmetry > 30.0%. Overall, every 10% increase in HGS asymmetry was associated with a 1.17 (CI: 1.05, 1.32) greater odds of future morbidity accumulation. Additionally, asymmetry between 10.1% - 20.0%, 20.1% - 30.0%, and > 30.0% was associated with a 1.10 (CI: 1.05, 1.15), 1.11 (CI: 1.04, 1.18), and 1.20 (CI: 1.09, 1.33) greater odds for morbidity accumulation during aging. These findings suggest that severe functional asymmetries may elevate the odds for accumulating morbidities.