Endothelin-1 levels are elevated in patients with type 2 diabetes mellitus and may contribute to impaired microvascular function. We investigated the effect of selective endothelin-A (ETA) receptor blockade (BQ123) on skin microcirculation in patients with type 2 diabetes and albuminuria.Methods
Ten type 2 diabetes patients and 8 non-diabetic controls were investigated. Nutritive skin capillary circulation, investigated by videophotometric capillaroscopy, and total skin microcirculation, assessed by laser Doppler fluxmetry (LDF), were studied during intra-arterial infusion of saline for 15 min, followed by BQ123 infusion for 60 min.Results
Following BQ123 infusion there was a significant increase in resting capillary blood cell velocity (CBV) in patients with type 2 diabetes from 0.24 (0.20–0.34) mm/s at baseline to 0.61 (0.46–0.88) mm/s at 60 min, but no significant change in the control subjects [0.55 (0.10–0.68) vs. 0.38 (0.13–0.88) mm/s; p < 0.005 for difference between groups]. Peak CBV following arterial occlusion and skin temperature increased significantly in the type 2 diabetes group but not in the control group during BQ123 infusion. There were no significant changes in LDF parameters during infusion of BQ123 in either group.Conclusion
ETA receptor blockade improves nutritive skin capillary circulation in patients with type 2 diabetes and microangiopathy.