Endothelium-dependent brachial artery flow-mediated vasodilatation in patients with diabetes mellitus with and without coronary artery disease.

Endothelial function as assessed by brachial artery flow mediated vasodilatation (FMD) has been shown to be impaired in patients with coronary artery disease (CAD). Since diabetes mellitus (DM) has been considered to be CAD risk-equivalent, we sought to determine whether endothelial dysfunction is present in patients with DM independent of presence of CAD.One hundred and ninety eight individuals were included in the study and divided into four groups: Group 1--patients with risk factors for CAD, but no DM or CAD; Group 2--patients with DM but no CAD; Group 3--patients with CAD but no DM and Group 4--patients with both DM and CAD. Brachial artery FMD assessment was performed once in all subjects and FMD was calculated as percentage increase in brachial artery diameter in response to increase in brachial artery flow.Mean FMD was significantly higher in Group 1 (7.03 +/- 2.87%) compared to the other three groups. Mean FMD in Group 2 (5.51 +/- 2.12%) was similar to that in Group 3 (4.56 +/- 2.70%; p value 0.195) but significantly higher than that in Group 4 (4.26 +/- 1.93%; p value 0.038). There was no statistically significant difference in mean FMD in Group 3 and Group 4 (p value 0.65).Endothelial function as assessed by FMD is significantly impaired in diabetics compared to non-diabetics in absence of CAD. In addition, similar degree of impairment in endothelial function is seen in diabetics without CAD and non-diabetic patients having CAD, implying CAD risk-equivalence of diabetes.