Abstract
Obesity is an independent risk factor for recurrent events among patients with established coronary heart disease (CHD). The goal of the present study was to identify potential mechanisms underlying this association. We measured the waist-to-hip ratio and body mass index in 979 outpatients with stable CHD and followed them for a mean of 4.9 years. We used proportional hazards models to evaluate the extent to which the association of obesity with subsequent heart failure (HF) hospitalization or cardiovascular (CV) events (myocardial infarction, stroke, or CHD death) was explained by baseline co-morbidities, cardiac disease severity, inflammation, insulin resistance, neurohormones and adipokines. Of the 979 participants, 128 (13%) were hospitalized for HF and 152 (16%) developed a CV event. Each standard deviation (SD) increase in the waist-to-hip ratio was associated with a 30% increased risk of HF hospitalization (unadjusted hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.1 to 1.6). This association was not attenuated after adjustment for potential mediators (HR 1.6, 95% CI 1.2 to 2.1). Likewise, each SD increase in the waist-to-hip ratio was associated with a 20% greater risk of CV events (unadjusted HR 1.2, 95% CI 1.0 to 1.4), and this remained unchanged after adjustment for potential mediators (adjusted HR 1.3, 95% CI 1.0 to 1.5). The body mass index was not associated with the risk of HF or CV events. In conclusion, abdominal obesity is an independent predictor of HF hospitalization and recurrent CV events in patients with stable CHD. This association does not appear to be mediated by co-morbid conditions, cardiac disease severity, insulin resistance, inflammation, neurohormones, or adipokines.