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 0.921.06; 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.