Exercise training improves physical fitness and vascular function in children with type 1 diabetes.

Children with type 1 diabetes mellitus (DM1) show endothelial dysfunction and mild artery wall thickening compared to their age-matched healthy peers. In this study, we examined the effect of 18-week exercise training on physical fitness and vascular function and structure in children with DM1. We examined physical fitness, brachial artery endothelial function [flow-mediated dilation (FMD)], common carotid artery diameter, wall thickness and wall-to-lumen ratio before and after 18-week exercise training in children with DM1 (n = 7). Physical fitness, measured as maximal oxygen consumption, improved after training (p = 0.039). Brachial artery FMD improved from 7.5 ± 4.2 to 12.4 ± 5.2 (p = 0.038). Carotid artery diameter, wall thickness and wall-to-lumen ratio did not change significantly (p = 0.26, 0.53 and 0.27, respectively). We showed that exercise training in children with DM1 effectively reverses endothelial dysfunction and improves physical fitness. These data emphasize the important role for physical activity in the management of DM1.