Discrepancy in skin capillary circulation between fingers and toes in patients with type 1 diabetes.

The aim of the present study was to investigate skin microcirculation in patients with diabetes to see if any differences in microvascular reactivity could be found between a skin area with low (fingers) or high risk (toes) of complications. Twelve male patients with type 1 diabetes were investigated, the age was 34.7 +/- 8.5 years, and diabetes duration 12.8 +/- 7.7 years (mean +/- SD). Twelve healthy male subjects served as controls. Capillary blood cell velocity (CBV) in the nailfolds of the great toe and left fourth finger was investigated with videophotometric capillaroscopy, and total skin microcirculation with laser Doppler fluxmetry (LDF). CBV and LDF were studied during rest, and following a 1-min arterial occlusion at the proximal phalanx of the digit. Skin temperature was similar in patients and controls. The diabetic patients showed normal CBV and LDF values in skin microcirculation of the fingers, while a reduced (p < 0.01) CBV was found during reactive hyperemia in the toes. The ratio between CBV and LDF was decreased (p < 0.01), indicating a maldistribution of blood between skin capillaries and subpapillary vessels in the toes of diabetic patients. These disturbances may be of importance for the development of foot complications in diabetic patients.