Association between relative handgrip strength and cardiovascular disease among Korean adults aged 45 years and older

Abstract

BACKGROUND: Aging causes both structural and functional changes in the skeletal muscle, and is associated with changes in body composition form, which results in an increased incidence of cardiovascular death. Sarcopenia is the age-related decline in skeletal muscle mass, which is accompanied by decreased muscle strength and function. Handgrip strength (HGS) is a simple, fast, reliable, and cost-effective tool for measuring muscle strength. However, previous studies have shown inconsistent results when they have used other criteria to identify muscle weakness, or they have used various indicators to determine handgrip strength. OBJECTIVE: We aimed to investigate which index was most suitable for predicting cardiovascular disease (CVD), and suggested the optimal cut-off points based on the handgrip strength index. In addition, we aimed to identify the effects of weak HGS, as determined by applying the optimal cut point on the development of CVD. METHOD: A total of 8,494 older men and women aged over 45 years from the Korean Longitudinal Study of Aging (KLoSA) were included in this study at baseline. We performed a generalized estimating equation (GEE) regression model in order to explore whether the probability of CVD has changed over time, and compared the best fit among three different HGS indices using the Quasi-Akaike Information Criterion (QIC). RESULTS: The relative HGS was strongly associated with CVD in both sexes, and the best fit model was in that in comparison to dominant HGS and absolute HGS (men: OR [odds ratio] per 1 SD increase in relative HGS = 0.839; 95% CI, 0.783–0.898; p < 0.0001; and women: OR per 1 SD increase in relative HGS = 0.795; 95% CI, 0.726–0.870; p < 0.0001). In addition, we calculated the optimal cut point for CVD based on the relative HGS in this study (men: < 2.52 and women: < 1.55, respectively), and demonstrated that low HGS, as determined by applying relative HGS cut points, was associated with a higher OR for CVD compared to normal HGS; the associations observed were consistent between the sexes (men: OR = 1.202; 95% CI, 1.112–1.300; p < 0.0001; and women: OR = 1.211; 95% CI, 1.124– 1.305; p < 0.0001). CONCLUSIONS: Our findings suggest that HGS has the potential to be a valuable screening tool for cardiovascular risk in clinical settings; this is advantageous in situations where blood sampling is not possible since HGS is easily measured and highly reproducible. It is necessary to pay attention to weak grip strength against body size in the elderly population.