Impaired hyperemic response of brachial artery with the presence of diabetes mellitus in patients with coronary artery disease: a preliminary study.

Microvascular reactivity was assessed in reactive hyperemic response of brachial artery in 10 patients with non-insulin-dependent diabetes mellitus and 34 non-diabetic patients. Each subject was diagnosed clinically as having angina pectoris and was examined by coronary angiography. Brachial arterial flow was determined by a pulsed Doppler velocity measurement, guided by a high-resolution B-mode imaging of the forearm. Peak systolic velocity at the basal state in diabetic and non-diabetic patients was comparable (0.53 +/- 0.03 versus 0.61 +/- 0.04 m/s, respectively; P = NS). The velocity ratio of the peak systolic flow at the basal state to the maximum velocity during hyperemia of 2 min arterial occlusion tended to be less in diabetic than in non-diabetic patients (1.76 +/- 0.14 versus 2.15 +/- 0.13, respectively; P = NS). The duration of hyperemic flow was less in diabetic than in non-diabetic patients (6.7 +/- 0.7 versus 9.9 +/- 0.6 s, respectively; P < 0.02). Such alterations in reactive hyperemia may be relevant to the microvascular disorder of the peripheral vessel in the presence of diabetes mellitus.