Functional and structural vascular adaptations following 8 weeks of low volume high intensity interval training in lower leg of type 2 diabetes patients and individuals at high risk of metabolic syndrome

We wished to investigate the effects of 8 weeks of low volume high intensity interval training (HIIT) on endothelial function of popliteal artery and circulating cell adhesion molecules in type 2 diabetes (T2D) patients and matched controls (CON). Methods: Over 8 weeks, non-active T2D patients and CONs cycled three times per week (10x60sec HIIT). Pre- and post-HIIT measurements of endothelial function were conducted by applying flow-mediated dilation (FMD) along with taking venous blood samples. Results: Baseline diameter of popliteal artery increased significantly from an average of 5.53mm to 5.97mm (approximate to 8%) in the CON-group (p=0.006) and 5.32mm to 5.61mm (approximate to 6%) in the T2D-group (p=0.009). Peak diameter increased significantly from 5.82mm to 6.36mm (approximate to 9%) in the CON-group (p=0.001) and 5.57mm to 5.93mm (approximate to 7%) in the T2D-group (p=0.004). FMD% increased significantly from 5.12% to 6.58% in the CON-group (p=0.004) and 4.84% to 5.66% in the T2D-group: (p=0.045). The shear rate reduced significantly in both groups (CON-group: p=0.04; T2D-group: p=0.002). Circulating cell adhesion molecules remained unchanged (p>0.05). Conclusion: HIIT induced an improvement of endothelium-dependent FMD and significant outwards artery modelling. No changes in circulating cell adhesion molecules were observed.