The association between aortic distensibility and coronary flow reserve in newly diagnosed diabetic patients

Aortic distensibility (AD) is an important parameter affecting coronary hemodynamics. Coronary flow velocity reserve (CFVR) is a reliable marker of coronary endothelial function in diabetic patients. The aim of this study was to investigate the association between AD and CFVR in newly diagnosed diabetic patients.

We studied 77 patients with newly diagnosed diabetes mellitus (DM) and 30 age- and sex-matched healthy control subjects. CFVR was calculated as the hyperemic to resting coronary diastolic velocities ratio by using transthoracic echocardiography. Pulse pressure (PP) and AD were calculated.

Fasting blood glucose, HbA1c and PP were significantly higher in patients with diabetes (P < 0.001, P < 0.001 and P = 0.009, respectively). Other clinical and demographical characteristics, laboratory findings and echocardiographic findings were similar in both groups (P > 0.05, for all). The measurement of CFVR and AD in patients with diabetes were significantly lower compared with the controls (P < 0.001 and P = 0.001, respectively). CFVR was significantly negatively correlated with age, body mass index, HbA1c, systolic blood pressure, and PP, while significantly positively correlated with AD (P < 0.05, for all). Multivariate regression analysis showed that only AD (β = 0.485, P < 0.0001) and HbA1c (β = -0.362, P < 0.0001) were independently associated with CFVR. The cutoff value of AD obtained by the receiver operator characteristic (ROC) curve analysis was 2.44 for the prediction of impaired CFVR.

Aortic distensibility and HbA1c were independently associated with CFVR. The decrease in AD may be used as a marker of impaired coronary microcirculation in asymptomatic diabetic patients.