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 18.5-24.99kg/m), while 7,841 (51%) patients were classified as overweight (BMI 25-29.99kg/m), 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.