Obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries

OBJECTIVES This study evaluates the impact of obesity on coronary endothelial function in patients with normal or mild coronary artery disease. BACKGROUND The American Heart Association (AHA) has recently classified obesity as a modifiable risk factor for coronary heart disease. METHODS A total of 397 consecutive patients with normal or mildly diseased coronary arteries at angiography underwent coronary vascular reactivity evaluation using intracoronary adenosine, acetylcholine and nitroglycerin. Patients were divided into three groups based on the body mass index (BMI): Group 1, patients with a BMI <25 (n = 117, normal weight); Group 2, patients with a BMI 25–30 (n = 149, overweight) and Group 3, patients with a BMI >30 (n = 131, obese). RESULTS There were no significant differences among the groups in regard to other cardiovascular risk factors, except that overweight but not obese patients were significantly older than normal-weight patients (47 ± 1 years in Group 1, 53 ± 1 years in Group 2 and 50 ± 1 years in Group 3, p < 0.001). The percent change of coronary blood flow to acetylcholine (%Δ CBF Ach) was significantly lower in the obese patients than in the normal-weight group (85.2 ± 12.0% in Group 1, 63.7 ± 10.0% in Group 2 and 38.1 ± 9.6% in Group 3, P = 0.009). By multivariate analysis, overweight (odds ratio, 1.55; 95% confidence interval, 1.2–2.0) and obesity (odds ratio, 2.41; 95% confidence interval, 1.5–4.0) status were independently associated with impaired coronary endothelial function. CONCLUSIONS The study demonstrates that obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries.