The Association of Body Mass Index and 20-Year All-Cause Mortality Among Patients With Stable Coronary Artery Disease

Background: Limited data exist regarding the long-term association of body mass index (BMI) and all-cause mortality among patients with stable coronary artery disease (CAD). Accordingly, the aim of this study is to explore the association between BMI and long-term all-cause mortality among patients with stable CAD. Methods: Our study included 15,357 patients with stable CAD who were enrolled in the Bezafibrate Infarction Prevention (BIP) registry between February, 1990 and October1992, and subsequently followed-up through December 2014. Results: 5,051 (33%) patients were classified as normal weight (BMI 18.5–24.99 kg/m ² ), while 7,841 (51%) patients were classified as overweight (BMI 25–29.99 kg/m ² ), and 2,465 (16%) as obese (BMI≥30). Kaplan-Meier survival analysis showed that at 20 years of follow-up the rate of all-cause mortality was significantly higher among obese patients (67%) compared to overweight (61%) and normal weight (61%); log rank p-value for the overall difference <0.001. Multivariable analysis showed that obese patients had an independently 12% greater mortality risk compared to normal weight patients (HR = 1.12; 95% CI 1.02–1.23; p = 0.02), whereas, overweight patients experienced a similar mortality risk as normal weight patients (HR = 0.99; 95% CI 0.92–1.06; p = 0.76). The mortality risk associated with obesity was pronounced among patients younger than 65 years (p-value for interaction<0.05). Conclusions: Our findings indicate that obesity is independently associated with increased risk for long-term mortality among patients with stable coronary artery disease, whereas overweight does not appear to confer an additional risk in this population.