Resting heart rate is associated with cardiovascular and all-cause mortality after adjusting for inflammatory markers: the Copenhagen City Heart Study

Abstract

Aims: To investigate the association between resting heart rate (RHR) and markers of chronic low-grade inflammation. Also, to examine whether elevated resting heart rate is independently associated with cardiovascular and all-cause mortality in the general population, or whether elevated RHR is merely a marker of chronic low-grade inflammation.

Methods and results: A group of 6518 healthy subjects from the the Danish general population were followed for 18 years during which 1924 deaths occurred. Subjects underwent assessment of baseline RHR, conventional cardiovascular risk factors, high-sensitivity C-reactive protein (hsCRP), and fibrinogen. RHR was associated with hsCRP and fibrinogen in uni- and multivariate models (p < 0.0001). A 10 beats per minute increase in RHR was associated with increased cardiovascular and all-cause mortality in univariate models - HR (95%CI) (1.21 (1.14-1.29) and 1.15 (1.11-1.19); multivariate models adjusted for conventional risk factors - 1.16 (1.09-1.24) and 1.10 (1.06-1.14); multivariate models including hsCRP - 1.14 (1.07-1.22) and 1.09 (1.05-1.14); fibrinogen - 1.15 (1.07-1.22) and 1.09 (1.05-1.14); and both hsCRP and fibrinogen - 1.14 (1.07-1.22) and 1.09 (1.05-1.14).

Conclusion: RHR was associated with markers of chronic low-grade inflammation. However, RHR remained associated with both cardiovascular and all-cause mortality after adjusting for markers of chronic low-grade inflammation. This suggests that RHR is an independent risk factor for cardiovascular and all-cause mortality, and not merely a marker of chronic low-grade inflammation.