Effects of a short‐term improvement in glycaemic control on skin microvascular dysfunction in Type 1 and Type 2 diabetic patients

Aims To investigate whether Type 1 and Type 2 diabetic patients differ in the effects of short‐term improvement in glycaemic control on skin microvascular dysfunction. Methods Fourteen Type 1 and 14 Type 2 diabetic patients admitted to hospital to improve glycaemic control were investigated. Two age‐ and sex‐matched groups of non‐diabetic subjects served as controls. Capillary blood cell velocity (CBV) was assessed at the dorsal middle phalangeal area of the ring finger at rest and after 3‐min arterial occlusion using laser Doppler anemometry. Results Comparing the measurements before and after improvement in glycaemic control, there were no significant changes in peak CBV, time to peak CBV and vasomotion amplitudes in Type 1 and Type 2 diabetic patients. On admission to hospital, time to peak CBV was prolonged in Type 1 (20.9 ± 2.9 vs. 12.3 ± 1.6 s, P = 0.003) and Type 2 diabetic patients (20.6 ± 2.6 vs. 11.9 ± 1.3 s, P = 0.021) compared with control subjects. After improvement in glycaemic control, there was no significant difference in time to peak CBV between Type 1 diabetic patients and their control subjects (17.8 ± 4.2 vs. 12.3 ± 1.6 s, P = 0.535). In Type 2 diabetic patients, the time to peak CBV increased non‐significantly. Conclusions Short‐term improvement in glycaemic control did not appear to reverse microcirculatory dysfunction in Type 1 and Type 2 diabetes. However, there was an improvement of the delayed reactive hyperaemia in Type 1 diabetic patients.