The effect of rowing on endothelial function and insulin action in healthy controls and in patients with type 2 diabetes

Patients with type 2 diabetes (T2DM) have an increased risk for cardiovascular disease. We examined the effects of 8 weeks of home-based rowing training (heart rate corresponding to 65-70% of VO2 peak) on endothelial function and glucose clearance (local and systemic effects) in male subjects with T2DM (n=9) and matched controls (n=8). Before and after training (30 min every other day), all subjects underwent sequential graded brachial artery infusions of non-insulin vasodilators (acetylcholine; sodium nitroprusside; adenosine). Forearm blood flow was improved by training in controls (without and with insulin: P=0.003 and 0.05, respectively) but not in subjects with T2DM. Likewise, whole body glucose clearance increased in response to training in controls (P=0.05) but not in T2DM. However, in both groups, the capacity for local forearm glucose extraction (controls: P=0.001; T2DM: P=0.002) and clearance (controls: P < 0.001; T2DM: P=0.01) were positively affected by exercise. While the subjects with T2DM did not respond to the same degree as controls to 8 weeks of home-based exercise, there are clear benefits as illustrated by improvements in local glucose disposal. Training of higher intensity or duration may be required in order to elicit a response similar to controls.