Low relative skeletal muscle mass predicts incident hypertension in Korean men: a prospective cohort study

Objective: Previous cross-sectional studies suggest an association between low muscle mass and hypertension. However, whether low muscle mass predicts the development of hypertension is unknown. The aim of this study is to investigate the relationship between relative muscle mass and incident hypertension in a large prospective cohort of Korean adults. Methods: In this prospective cohort study, we analyzed 132 324 participants without hypertension at baseline who underwent two health check-ups in 2012 and 2016 or in 2013 and 2017 with a 4-year interval. The participants were divided according to skeletal muscle mass index quartiles (Q1--Q4) according to their baseline skeletal muscle mass index [skeletal muscle mass index (%) = total skeletal muscle mass (kg)/body weight (kg) × 100). Multivariate logistic regression was used to estimate the odds ratio and 95% confidence interval for the development of hypertension after 4 years. Results: After 4 years, 7180 (5.43%) participants developed hypertension. The incidence rates of hypertension were 12.11, 8.58, 6.93, and 4.37% in men and 4.02, 2.29, 1.73, and 1.18% in women in Q1, Q2, Q3, and Q4, respectively. The multivariate adjusted odds ratios (95% confidence intervals) for incident hypertension in Q1, Q2, and Q3, in comparison with Q4, were 1.46 (1.3–1.63), 1.31 (1.19–1.46), and 1.26 (1.14–1.40) in men and 0.97 (0.76–1.23), 1.12 (0.90–1.38), and 1.14 (0.92–1.42) in women, respectively. Conclusion: Low relative skeletal muscle mass was independently and significantly associated with the incidence of hypertension only in Korean men. Further research is required to understand the underlying mechanisms of this relationship.