Obesity and Subtypes of Incident Cardiovascular Disease

TLDR

Obesity is a known risk factor for coronary heart disease, heart failure, and stroke, yet comparative associations across these subtypes and the extent to which they are independent of traditional mediators remain unclear. In the ARIC cohort of 13,730 adults without baseline CVD, researchers examined how higher BMI related to incident heart failure, coronary heart disease, and stroke, before and after adjusting for traditional cardiovascular mediators such as blood pressure, diabetes, and lipids. Over 23 years, severe obesity was most strongly linked to heart failure (HR 3.74) versus coronary heart disease (HR 2.00) and stroke (HR 1.75); adjustment for mediators eliminated the associations with coronary heart disease and stroke but not heart failure (HR 2.27), indicating an unexplained, stronger obesity–heart failure link that underscores the importance of weight management.

Abstract

Obesity is a risk factor for various subtypes of cardiovascular disease (CVD), including coronary heart disease (CHD), heart failure (HF), and stroke. Nevertheless, there are limited comparisons of the associations of obesity with each of these CVD subtypes, particularly regarding the extent to which they are unexplained by traditional CVD mediators. We followed 13 730 participants in the Atherosclerosis Risk in Communities (ARIC) study who had a body mass index ≥18.5 and no CVD at baseline (visit 1, 1987-1989). We compared the association of higher body mass index with incident HF, CHD, and stroke before and after adjusting for traditional CVD mediators (including systolic blood pressure, diabetes mellitus, and lipid measures). Over a median follow-up of 23 years, there were 2235 HF events, 1653 CHD events, and 986 strokes. After adjustment for demographics, smoking, physical activity, and alcohol intake, higher body mass index had the strongest association with incident HF among CVD subtypes, with hazard ratios for severe obesity (body mass index ≥35 versus normal weight) of 3.74 (95% CI 3.24-4.31) for HF, 2.00 (95% CI 1.67-2.40) for CHD, and 1.75 (95% CI 1.40-2.20) for stroke (P<0.0001 for comparisons of HF versus CHD or stroke). Further adjustment for traditional mediators fully explained the association of higher body mass index with CHD and stroke but not with HF (hazard ratio 2.27, 95% CI 1.94-2.64). The link between obesity and HF was stronger than those for other CVD subtypes and was uniquely unexplained by traditional risk factors. Weight management is likely critical for optimal HF prevention, and nontraditional pathways linking obesity to HF need to be elucidated.