Relation of serum uric acid and body mass index to mortality in high-risk patients with established coronary artery disease: A report from the ET-CHD registry, 1997–2006

Abstract

BackgroundHyperuricemia is associated with a higher risk of death in patients with coronary artery disease (CAD). In contrast, overweight or obesity was associated with survival benefits in this population. However, the relation of body mass index (BMI) and serum uric acid (SUA) to mortality has not been clarified in this population. MethodsWe studied a cohort of 1202 patients with angiographic CAD from the ET-CHD registry during 1997–2003 in Taiwan. To evaluate the relation of BMI and SUA on mortality, the subjects were categorized into 4 groups by BMI≧25kg/m2 (overweight or obesity) or BMI<25kg/m2 (normal- or under-weight), and SUA levels higher or lower than the median of 6.6mg/dl. At a median follow-up of 5.4 years, cardiac and all-cause deaths were the primary end points. ResultsMultivariate analyses demonstrated that high SUA group had a significantly higher cardiac mortality [hazard ratio (HR): 1.79, 95% confidence interval (CI): 1.14–2.82, p=0.023] and overall mortality (HR: 1.68, 95% CI: 1.19–2.36, p=0.003) than low SUA group only in overweight or obese patients. Additionally, high BMI was associated with a significantly lower cardiac mortality (HR: 0.58, 95% CI: 0.38–0.99, p=0.023) and overall mortality (HR: 0.62, 95% CI: 0.41–0.82, p=0.003) than low BMI in patients with low SUA levels. Furthermore, normal-low weight and underweight patients (BMI<21kg/m2) were found to have a higher risk of mortality regardless of SUA levels. ConclusionsAmong patients with established CAD, SUA may be a potent predictor to mortality in overweight or obese patients. Moreover, the obesity-mortality paradox phenomenon was mainly driven by higher mortality risk in underweight patients and lower mortality risk in overweight and obese patients with low SUA.