Effects of exercise training on carotid intima-media thickness in patients with type 2 diabetes and coronary artery disease. Influence of carotid plaques

Background: Carotid intima-media thickness (cIMT) holds prognostic information for future cardiovascular disease and is associated with the extent of coronary atherosclerosis. We investigated the effect of exercise on cIMT progression in patients with both type 2 diabetes and coronary artery disease (CAD). Methods: Patients with type 2 diabetes and CAD (n = 137) were randomized to exercise training or standard followup. The 12 month exercise program contained 150 min weekly of combined aerobic and resistance training. High-resolution ultrasonography of the distal part of the common carotid artery (CCA) was performed to measure cIMT before and after the intervention. The CCA and the carotid bulb were scanned for the presence of atherosclerotic plaques. Differences in changes between the randomized groups were calculated by one-way ANCOVA. Results: In the total population no difference in changes of cIMT from baseline to 12 months was observed between the exercise group and controls [-0.016 mm (95 % CI -0.037 to 0.006) vs. -0.007 mm (95 % CI -0.029 to 0.015), p = 0.57]. However, there was a significant interaction between the effect of exercise training and the presence of carotid plaques (p = 0.013), and significant reduced cIMT was demonstrated in the exercise group compared with controls in patients without identified carotid plaques (n = 65) [-0.034 mm (95 % CI -0.060 to 0.008) vs. 0.013 mm (95 % CI -0.011 to 0.038), p = 0.010]. Conclusion: One year of exercise training in patients with type 2 diabetes and CAD did not significantly change cIMT progression. However, in patients without identified carotid plaques, beneficial effect of exercise training on cIMT progression was demonstrated.