Handgrip strength, dynapenia, and health-related quality of life in older Korean adults.

BACKGROUND

Handgrip strength (HGS) is a critical determinant of muscle function and has been strongly associated with various health outcomes, including health-related quality of life (HRQoL) in older adults. Although previous studies have explored the relationship between HGS and HRQoL, there is limited research on multiple muscle strength indicators in older Korean adults. In this study, we aimed to investigate the associations between multiple muscle strength indicators-maximal and relative HGS, dynapenia, and HGS asymmetry-and HRQoL in older Korean adults.

METHODS

In this cross-sectional study, we utilized data of 4,260 community-dwelling individuals aged ≥ 65 years who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) 2016-2018. We assessed muscle strength using a digital dynamometer and defined dynapenia according to the criteria established by the Asian Working Group for Sarcopenia. HGS asymmetry was characterized by an interlimb difference of > 10%. HRQoL was evaluated using the EuroQol 5-Dimension (EQ-5D) index. Multivariable logistic regression models were employed to assess the associations between muscle strength indices and the high-risk group for low HRQoL (EQ-5D index ≤ 0.677), adjusting for potential confounders.

RESULTS

Of the 4,260 participants, 56.5% were female; 17.4% aged ≥ 80 years. A total of 8.3% of the participants were categorized as being at high risk for low HRQoL. Lower maximal HGS (adjusted odds ratio [aOR] = 1.065, 95% confidence interval [CI] = 1.023-1.108) and lower relative HGS (aOR = 1.136, 95% CI = 1.026-1.257) were significantly associated with poor HRQoL in women. Furthermore, dynapenia was independently correlated with a higher risk of impaired HRQoL in women (aOR = 1.497, 95% CI = 1.064-2.106), whereas no significant association was observed in men. HGS asymmetry was not significantly associated with HRQoL in either sex after adjusting for confounders.

CONCLUSIONS

Reduced HGS and the presence of dynapenia were significantly associated with lower HRQoL, particularly among women. These findings highlight the critical role of muscle strength in maintaining the well-being of aging populations. Further longitudinal studies are warranted to validate these associations and elucidate potential causal mechanisms.