We have previously reported insignificant changes in HbA1c after exercise in patients with both type 2 diabetes and coronary artery disease. In this study, we investigated the effect of exercise on endothelial function and possible associations between changes in endothelial function and HbA1c.
Patients with type 2 diabetes and coronary artery disease (n = 137) were randomised to 12 months exercise or standard follow-up. Endothelial function was assessed by circulating biomarkers (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, von Willebrand factor, tissue plasminogen activator antigen, asymmetric dimethylarginine and L-arginine/asymmetric dimethylarginine ratio). Differences between the randomised groups were analysed by analysis of covariance and correlations by Spearman’s rho or Pearson’s correlation.
No effect of exercise on endothelial function was demonstrated. The changes in HbA1c in the exercise group correlated with changes in E-selectin (r = 0.56, p < 0.001), intercellular adhesion molecule-1 (r = 0.27, p = 0.052), vascular cell adhesion molecule-1 (r = 0.32, p = 0.022) and tissue plasminogen activator antigen (r = 0.35, p = 0.011). HbA1c decreased significantly more in patients with versus without a concomitant reduction in E-selectin (p = 0.002), intercellular adhesion molecule-1 (p = 0.011), vascular cell adhesion molecule-1 (p = 0.028) and tissue plasminogen activator antigen (p = 0.009).
Exercise did not affect biomarkers of endothelial function in patients with both type 2 diabetes and coronary artery disease. However, changes in biomarkers of endothelial activation correlated with changes in HbA1c, and reduced endothelial activation was associated with improved HbA1c after exercise.