Changes in vascular structure in diabetic patients after 8 weeks aerobic physical exercise: a randomized controlled trial

Diabetes is a highly prevalent metabolic disease with macrovascular and microvascular complications. Insulin resistance plays a major role in the pathogenesis of atherosclerosis in type 2 diabetes patients. The risk of atherosclerosis progress in diabetes is of 2-4 orders of magnitude. Early atherosclerosis can be detected by carotid intima-media thickness (cIMT) ultrasonography. There is an inverse relationship between intima-media thickness and physical activity. The aim of this study was to investigate the effects of an 8-week aerobic exercise program on the vascular structure in different segments of the carotid artery. This study was a randomized control trial. Thirty individuals were selected out of 642 volunteers who fulfilled the inclusion criteria. They were randomly divided into aerobic exercise and control groups by a block randomization method. This study was carried out during May-October 2016 in Iran. The aerobic protocol comprised of 24 sessions of aerobic exercise on a treadmill for 30 min per session, 3 days a week. The intensity of the training protocol was 50-70% of the patient's max heart rate. Measurements of vascular parameters were evaluated by the same person, before and after the 24-session intervention. There were no significant differences between anthropometric, sex, age, diabetic history, and cardiac ejection fraction, compared to baseline characteristics. Intima-media thickness (0.52 +/- 0.12), intima-media/lumen (0.07 +/- 0.02) in bulb carotid, common carotid, and internal carotid, as well as bulb wall, were reduced significantly in the training group compared to the control group after 8 weeks (p < 0.05). Twenty-four sessions of aerobic exercise improved vascular parameters in type 2 diabetics.