Turk Kardiyol Dern Ars. 2009; 37(6): 391-396

Decreased coronary flow reserve in obese women

Serpil Eroğlu, Leyla Elif Sade, Hüseyin Bozbaş, Haldun Müderrisoğlu
Department of Cardiology, Medicine Faculty of Başkent University, Ankara

OBJECTIVES
Obesity is associated with an increased rate of cardiovascular disease and risk factors. It is a common problem in apparently healthy women. We aimed to investigate the association between obesity and coronary flow reserve (CFR) in obese women.

STUDY DESIGN
The study included 80 consecutive women (mean age 55.6±10.2 years) without diabetes mellitus and clinical coronary artery disease. Body mass index (BMI) was calculated and obesity was defined as BMI ≥30 kg/m2. Based on BMI, the patients were grouped as normal weight (n=13; 18.5-24.9 kg/m2), overweight (n=32; 25-29.9 kg/m2), obese (n=32; ≥30-39.9 kg/m2), and morbid obese (n=3; ≥40 kg/m2). Peak diastolic coronary flow velocities were measured in the distal left anterior descending artery by transthoracic pulsed wave Doppler echocardiography at baseline and after dipyridamole infusion and CFR was calculated as the ratio of hyperemic to baseline peak diastolic velocities.

RESULTS
There were 35 obese women (43.8%). Coronary flow reserve was significantly lower in obese women than in nonobese subjects (2.2±0.5 vs. 2.5±0.4; p=0.022). The lowest CFR was seen in patients with a BMI of ≥40 kg/m2; overweight women did not differ significantly from women of normal weight. Coronary flow reserve was correlated with BMI (r=-0.314, p=0.005), waist circumference (r=-0.316, p=0.005), C-reactive protein (CRP) (r=-0.342, p=0.011), and adiponectin level (r=0.410, p=0.011). In regression analysis, BMI (p=0.017), waist circumference (p=0.048), systolic blood pressure (p=0.025), fasting glucose (p=0.035), and adiponectin level (p=0.037) were found to be independent predictors for impaired CFR. In ROC analysis, the cut-off value for BMI to predict impaired CFR was ≥30 kg/m2, with 76% sensitivity and 72% specificity (ROC area 0.805, p<0.001, 95% CI 0.669-0.96).

CONCLUSION
Impaired CFR in obese women suggests the presence of microvascular dysfunction. Treatment of obesity is important for the prevention of atherosclerosis.

Keywords: Blood flow velocity, body mass index, coronary circulation, echocardiography; female; obesity/complications; risk factors; vascular resistance.

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