Differential associations of resting heart rate and heart rate variability indices with cardiovascular and coronary heart disease mortality risk: the prospective KORA study.

Limited data exist on the relationship of resting heart rate (RHR) and heart rate variability (HRV) indices with cardiovascular (CVD) and coronary heart disease (CHD) mortality in individuals with and without (pre)diabetes. We investigated overall and glucose tolerance status-specific association of RHR and a large number of HRV indices with incident long-term CVD and CHD mortality. RHR and 66 HRV indices were obtained from five-minute electrocardiogram performed at baseline (KORA S4; 1999-2001) in 1390 adults from the prospective Cooperative Health Research in the Region of Augsburg (KORA). CVD and CHD mortality were ascertained over a 22-year follow-up. Linear and non-linear association of RHR and indices with mortality in the overall sample and normal glucose tolerance (NGT), prediabetes and type 2 diabetes subsamples were determined using Cox models. Independent of covariates, RHR was directly associated with CVD (1.20 [1.04, 1.39], P = 0.013) and CHD (1.32 [1.08, 1.62], P = 0.007) mortality in the overall study sample. Additionally, very-low frequency power (VLF) was directly associated with CVD mortality (1.17 [1.01, 1.37]; P = 0.038) in NGT. Square root of the mean squared differences of successive NN intervals (RMSSD) showed non-linear association with CVD mortality in type 2 diabetes. Number of data points in the 8th column of a 12 × 12 matrix (SPPA_c_8) was inversely associated with CVD mortality (0.54 [0.32, 0.93], P = 0.025) in prediabetes. These findings suggest that RHR and HRV indices provide differential and complementary insights into long-term CVD mortality risk in the general population.