Low relative muscle mass and left ventricular diastolic dysfunction in middle-aged adults

Objectives: The association between low skeletal muscle mass and left ventricular diastolic dysfunction (LVDD), a predictor of future heart failure, is largely unexplored. We investigated the relationship between relative muscle mass and LVDD. Methods: We conducted a cross-sectional study in 67,106 Koreans who underwent an echocardiography as part of a comprehensive health examination between January 2012 and December 2014. Skeletal muscle mass index (SMI) [SMI (%) = total skeletal muscle mass (kg) / body weight (kg) × 100] was estimated using a bioelectrical impedance analyzer. The presence of LVDD was determined using echocardiographic findings. Results: In 67,106 participants, 19,232 subjects (28.7%) and 1553 subjects (2.3%) had LVDD and left ventricular (LV) hypertrophy, respectively. SMI was positively associated with E/A ratio and septal E′, whereas E/E′ ratio and LV mass index were negatively associated with SMI. Lower SMI was associated with increased presence of LVDD. In a multivariable-adjusted model controlling for potential confounders including physical activity, insulin resistance, and LV mass, the odds ratios for LVDD in SMI quartiles 1, 2, and 3 compared with quartile 4 were 2.11 (1.97–2.25), 1.79 (1.68–1.90), and 1.45 (1.36–1.55), respectively (P for trend < 0.001). Conclusions: In a large sample of young and middle-aged Korean adults, low relative muscle mass was independently associated with increased risk of LVDD, indicating an independent role of skeletal muscle mass in the pathogenesis of LVDD.