Comparison of grip strength measurements for predicting all-cause mortality among adult aged 20+ years: NHANES 2011-2014

Abstract Background Little is known about the optimal measure of handgrip strength for predicting all-cause mortality and whether this association is modified by age or sex. Methods We used data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES), 9,583 adults aged ≥ 20 years were included. Equal-length grip strength was measured using a digital handheld Takei dynamometer. We defined four measurements of grip strength, i.e., the average of the maximum of both hands (HGS), the maximum of dominant hand (MGS), HGS/BMI, and MGS/weight, and three indicators of low grip strength, namely, low reference grip strength, lowest 20% grip strength, and low grip strength in sarcopenia. Information on deaths were obtained through linkage to National Death Index (NDI). Cox regression was used to assess the association of grip strength with mortality risk. Results HGS, MGS, HGS/BMI, and MGS/weight were all inversely associated with all-cause mortality, with HGS (AUC = 0.714) being the optimal predictor of mortality, followed by MGS (AUC = 0.712). Participants with low grip strength showed increased risk of mortality regardless of which indicator was used, and the highest effect size was seen for lowest 20% grip strength group (HR = 2.20 for men, 2.52 for women). The above-mentioned correlations were consistently found in people of different age and sex. Conclusion This study suggests the simplest measure of absolute grip strength (HGS, MGS) was the optimal index for predicting all-cause mortality. Keep an adequate level of handgrip strength may be beneficial to reduce the risk of mortality.