Reduced lung function, C-reactive protein, and increased risk of cardiovascular mortality

Abstract

Background: We explored whether reduced lung function is a predictor of mortality due to cardiovascular or coronary artery disease (CVD or CAD), and, if this hypothesis is correct, whether C-reactive protein (CRP), a systemic inflammatory marker, is responsible for this association in a general population-based cohort. Methods and Results: We used the Third Nutrition and Health Examination Survey (NHANES III) database and the NHANES III Linked Mortality File. A total of 13,310 participants ≥20 years of age who completed a spirometric test at baseline examination were included. On comparison of the participants in the lowest forced vital capacity percent predicted (FVC% pred) quartile with those in the highest quartile, the hazard ratio (HR) was 2.1 (95% CI: 1.7–2.6) for cardiovascular mortality and 2.2 (95% CI: 1.6–3.2) for coronary mortality. A similar association was observed for forced expiratory volume in 1 s percent predicted (FEV1% pred). When the participants with the highest FVC% pred or FEV1% pred (Q4) and low CRP (≤0.22 mg/dl) were defined as the reference group, the adjusted HR for cardiovascular mortality was significantly increased in the individuals with the lowest spirometric volume (Q1), and the risk was prominent in individuals with high CRP (>0.22 mg/dl). Conclusions: There is a significant association between lung function parameters and death from CVD and CAD in the general population.