Obesity is associated with impaired human coronary endothelial function

Obesity is an independent risk factor for cardiovascular disease. Endothelial dysfunction assessed in the peripheral circulation is associated with obesity, however, little is known if this association also exists in the coronary circulation.

Stable patients with coronary artery disease were evaluated. Baseline characteristics were evaluated, including assessment of body mass index [(BMI), kg/m(2)]. Coronary diameter (quantitative coronary angiography) and blood flow (0.014 in. Doppler Flo-wire) were measured at baseline and in response to intracoronary acetylcholine (10(-7) and 10(-6) M) to evaluate endothelial dependent effects with endothelial independent effects evaluated in response to intracoronary nitroglycerin and adenosine. The cohort was divided into tertiles around BMI values, i.e. normal weight (BMI < 25), overweight (BMI 25-29.9) and obese (BMI ≥ 30) groups.

83 patients were evaluated, with 20 patients in the normal weight (BMI 22.6 ± 0.3 kg/m(2)), 40 subjects in the overweight (BMI 27.3 ± 0.2 kg/m(2)) and 23 in the obese (BMI 34.3 ± 0.3 kg/m(2)) groups. A significant difference was seen in the primary endpoint of Ach mediated % change in coronary blood flow between the normal (101 ± 28%) and the obese (37 ± 15%) groups (p = 0.04). No significant difference was observed in epicardial constrictor response to acetylcholine across these three groups of patients.

In a cohort of subjects with coronary artery disease, patients with a high BMI had associated impaired microvascular coronary endothelial dependent function.