Associations between the severity of metabolic syndrome and cardiovascular autonomic function in a Chinese population.

BACKGROUND: The purpose of this study was to evaluate associations between the severity of metabolic syndrome (MetS) and cardiovascular autonomic function (CAF) in a Chinese population. METHODS AND MATERIALS: We conducted a large-scale community-based cross-sectional study to estimate associations between MetS and CAF in a Chinese population. The study included 2119 subjects. MetS was defined in accordance with the criteria published by the International Diabetes Federation. CAF was assessed via heart rate variability (HRV) and baroreflex sensitivity (BRS). Univariate and multivariate linear regression (MLR) analyses were undertaken to evaluate the statistical significance of the associations investigated. RESULTS: Three HRV components differed significantly between the groups with regard to MetS severity scores; total power (TP), low frequency power (LF), and high frequency power (HF), and BRS components also differed significantly between the groups (p<0.05 for each component). Univariate and MLR analysis revealed that MetS severity and insulin resistance (IR) were significantly associated with HRV and BRS components (β=-0.08~-0.16, p<0.05 for both). Fasting plasma glucose (FPG) and blood pressure (BP) were also negatively correlated with favorable outcomes (β=-0.042~-0.119, p<0.05 for both). CONCLUSIONS: In this study, MetS and IR were each significantly and independently negatively associated with CAF. Two MetS components, FPG and BP, were negatively correlated with CAF. Also, decreased HRV and BRS components were associated with increased MetS severity scores.