Abstract 13567: Resting Heart Rate is Associated with C-Reactive Protein in the Multi-Ethnic Study of Atherosclerosis (MESA)
Background: Resting heart rate (HR) is an independent predictor of all-cause and cardiovascular disease (CVD) mortality among individuals with and without prior CVD. The mechanism by which elevated HR increases mortality is unclear. One hypothesis is that it is a marker of autonomic imbalance favoring sympathetic predominance, which could increase inflammation via innervation of the bone marrow and lymphoreticular system. We investigated the association between HR and the inflammatory biomarker high-sensitivity C-reactive protein (CRP).
Methods: MESA is a prospective cohort of 6814 men and women aged 45-84 free of clinical CVD at enrollment from 4 races/ethnicities. We analyzed baseline data from those with complete covariate data, including HR, CVD risk factors, and CRP (n=5949). HR was measured three times at 2 minute intervals by an automatic oscillometric device after a 5 minute rest, and the average of the 2nd and 3rd readings was used. Multivariable-adjusted linear regression was used to assess the association between HR and log-transformed CRP. Multivariable-adjusted logistic regression was used to study the association between HR and significant inflammation defined by CRP≥2 mg/L.
Results: Median CRP increased across HR quartiles. 2848 (48%) had an elevated CRP. Increasing HR and HR quartiles were significantly associated with increasing CRP and odds of high CRP even after covariate adjustment (Table). Metabolic syndrome defined by Adult Treatment Panel III was also strongly associated with high CRP. However, the association of HR with CRP was still significant and essentially unchanged even after adjustment for metabolic syndrome.
Conclusion: Among adults free of clinical CVD, resting HR was associated with significant subclinical inflammation and adds information to the metabolic syndrome construct. As with all cross-sectional studies, the direction of association is unclear, and prospective studies are warranted to elucidate this mechanism.
- © 2011 by American Heart Association, Inc.