Cycle Training improves vascular function and neuropathic symptoms in patients with type 2 diabetes and peripheral neuropathy: A randomized controlled trial

Diabetic peripheral neuropathy (DPN) is associated with peripheral arterial disease and endothelial dysfunction. We investigated the effect of exercise training on the measures of superficial femoral artery (SFA) and neuropathic symptoms in patients with DPN. In a randomized-controlled trial, 31 volunteers with established DPN were randomly assigned to experimental or control groups. Experimental group performed cycling exercise training (50%-70% of heart rate reserve, 30-45 min, 3 sessions/week) over 12 weeks. Before and 48 h after the experimental period a 5-min flow mediated dilation (FMD) response in SFA using Color Doppler Ultrasonography, fasting glucose level, HbA1c and neuropathic score were assessed. FMD% significantly increased in the experimental group (from 3.2 ± 1.1% to 5.7 ± 1.2%) compared to the control condition (P = 0.0001). However, no significant alteration occurred in baseline membrane diameter and intima media thickness (P > 0.05). We also observed a significant improvement in fasting glucose, HbA1c and Michigan Diabetic Neuropathy Score (MDNS) following exercise intervention (all P < 0.05). Linear regression analysis indicated that the change in MDNS was significantly associated with the change in HbA1c (R Square = 0.34, standardized coefficients Beta = -0.58, P = .001) and FMD (R Square = 0.37, standardized coefficients Beta = 0.61, P = .001). This finding may be clinically of considerable importance as metabolic and vascular factors have been indicated to be involved in the development of DPN.