Exercise training but not rosiglitazone improves endothelial function in prediabetic patients with coronary disease

Impaired glucose tolerance (IGT) is associated with endothelial dysfunction and upregulation of inflammatory markers, which is potentially reversible by adequate treatment. It was our aim to compare the impact of exercise training with that of rosiglitazone on endothelial function and inflammatory markers in patients with IGT and coronary artery disease (CAD).

Patients with IGT and CAD were randomly assigned to either exercise training (n=13), rosiglitazone (8 mg; n=11), or a control group (n=10). During the first week, exercise training consisted of 6 x 15 min/d followed by three weeks of 30 min/d submaximal ergometer exercise. In addition, group exercise training of 1 h was performed twice per week.

After 4 weeks, triglycerides and uric acid were significantly lower in the exercise group whereas fasting glucose, HbA1c, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, C-reactive protein, fibrinogen, and body mass index did not differ between groups. In the exercise group, exercise capacity (123+/-33 vs. 144+/-31 W; P=0.006) and endothelium-dependent, flow-mediated vasodilatation (P<0.01) increased significantly, whereas in the rosiglitazone group and in the control group (P=n.s.) no changes were seen.

In patients with IGT and CAD, 4 weeks of exercise training exert significant and superior improvement of endothelium-dependent vasodilatation as compared with rosiglitazone therapy or usual care. This finding should be seen as an even further encouragement to recommend and, where available, prescribe exercise training to our patients.