Background: Women may have atypical clinical presentations and atypical risk factors of coronary artery disease. Adiponectin has anti-insulin-resistant properties and antiatherogenic effects. We investigated the association between serum adiponectin levels and coronary flow reserve (CFR) in women with normal coronary arteries.
Methods: CFR was assessed in 45 consecutive women (mean age 54.2+/-9.2 years) with normal epicardial coronary arteries by coronary angiography. Serum adiponectin, C-reactive protein, insulin, and glucose levels were examined and Homeostasis Model Assessment for Insulin Resistance index was calculated. Peak diastolic coronary flow velocities were measured in distal left anterior descending artery at baseline and after dipyridamole infusion by transthoracic pulsed wave Doppler echocardiography. CFR was calculated as the ratio of hyperemic to baseline peak diastolic velocities. A CFR value > or =2 was accepted as normal.
Results: Adiponectin levels were lower in patients with impaired CFR than those with normal CFR (7.1+/-2.3 vs. 13.8+/-6.7 microg/ml P<0.001). Adiponectin levels were correlated with CFR (r=0.531, P<0.001) and inversely correlated with C-reactive protein (r=-0.308, P=0.047), insulin (r=-0.426, P=0.008), and Homeostasis Model Assessment for Insulin Resistance index (r=-0.442, P=0.004). Adiponectin levels of < or =8.5 muU/ml had 83% sensitivity and 93% specificity [receiver operating characteristic area 0.084, P<0.001, 95% confidence interval (0.56-1.08)] for predicting impaired CFR.
Conclusion: Decreased adiponectin levels are associated with impaired CFR in women with normal epicardial coronary arteries and hypoadiponectinemia may be a risk factor for impaired CFR in women.