Hypertension Characterizes Impairment of Coronary Flow Reserve in Patients with Diabetes

The aim of this study is to assess the differences in coronary flow reserve (CFR) in diabetic patients with and without mild hypertension, using non-invasive transthoracic Doppler echocardiography. This study included 12 healthy controls and 28 relatively controlled diabetic patients (13 with and 15 without hypertension). No patients had evidence of coronary artery diseases and left ventricular hypertrophy. We evaluated diastolic blood flow velocity in the left anterior descending coronary artery (LAD) at rest and after maximal vasodilation by adenosine infusion, using high resolution transthoracic Doppler Echocardiography. CFR was defined as the ratio of peak hyperemic to basal averaged peak velocity in the LAD. There was no difference in age, HbA1C and LV mass index between diabetic patients with and without hypertension. Compared to the normotensive group (3.0 ± 0.6), CFR was significantly decreased in diabetic patients with hypertension (2.4 ± 0.3). However, CFR of diabetic patients without hypertension (2.9 ± 0.6) did not decrease, significantly. According to our previous study, impairment of CFR could be also found in hypertensive patients without left ventricular hypertrophy. We conclude that hypertension should characterize impairment of CFR in patients with relatively controlled diabetic mellitus.