Haemodialysis is associated with changes in cutaneous microcirculation in diabetes mellitus

Aims To examine the cutaneous microcirculation on the dorsum of the foot before, during and after haemodialysis in diabetic and non‐diabetic patients. Methods Fourteen age‐matched patients (seven diabetic, seven non‐diabetic) without active foot ulceration were studied. Cutaneous microcirculation was assessed using a micro‐lightguide spectrophotometer to measure venous oxygen saturation and relative blood flow determined at two tissue depths: 2 and 6 mm. Cumulative relative changes of each parameter during haemodialysis were calculated as area under the curve. Differences between and within the groups were calculated by Mann–Whitney U‐test and anova following post hoc testing, respectively. Results At baseline, relative blood flow at 6 mm tissue depth was significantly greater in diabetic patients (P = 0.048). Thirty minutes after the end of dialysis, relative blood flow at 2 and 6 mm tissue depth was significantly higher in non‐diabetic patients (P = 0.048 and P = 0.001). Mean cumulative relative changes in venous oxygen saturation and relative blood flow at 2 mm as well as 6 mm tissue depth were positive for non‐diabetic subjects and negative for diabetic patients. Conclusions Haemodialysis is associated with changes in cutaneous microcirculation, which differ between people with and without diabetes. In those without diabetes, we found an increase in blood flow during haemodialysis, whereas blood flow was reduced in diabetic patients. This may be the result of abnormal vasomotor regulation due to distal neuropathy.