Association of absolute and relative hand grip strength with all-cause mortality among middle-aged and old-aged people

OBJECTIVES: This study aimed to examine the association of absolute and relative hand grip strength (HGS) with the risk of all-cause mortality among middle-aged and old-aged people in South Korea. Considering that both absolute HGS and relative HGS could be effective measures, an in-depth investigation is necessary to compare the effects of both measures on mortality. METHODS: Data of 9,102 participants, derived from the Korean Longitudinal Study of Aging from 2006 to 2018, were examined. HGS was divided into two categories: absolute HGS and relative HGS (defined as HGS divided by body mass index). The risk of all-cause mortality was the dependent variable. Cox proportional hazard regression was used to analyze the association between HGS and all-cause mortality. RESULTS: The average of absolute and relative HGS were 25.6 ± 8.7 kg and 1.1 ± 0.4 kg/BMI, respectively. The all-cause mortality rate decreased by 3.2% as absolute HGS increased by 1 kg (adjusted hazard ratio [HR] = 0.968, 95% CI = 0.958–0.978). An increase in relative HGS by 1 kg/BMI was associated with a 22% reduction in risk of all-cause mortality (adjusted HR = 0.780, 95% CI = 0.634–0.960). Individuals with more than two chronic diseases, there was a decrease in all-cause mortality as absolute HGS increased by 1 kg and relative HGS by 1 kg/BMI (absolute HGS; adjusted HR = 0.97, 95% CI = 0.959–0.982, relative HGS; adjusted HR = 0.483, 95% CI = 0.325–0.718). CONCLUSIONS: Our study findings showed that both absolute and relative HGS were inversely associated with the risk of all-cause mortality; a higher absolute/relative HGS was associated with a lower risk of all-cause mortality. Moreover, these findings highlight the importance of improving HGS to alleviate the burden of adverse health problems. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-023-04008-8.