Skin microvascular function in patients with type 1 diabetes: An observational study from the onset of diabetes

The development of disturbances in skin microcirculation in type 1 diabetes is not well characterised. We assessed skin microcirculation longitudinally from the onset of diabetes up to 29 years of duration to investigate when such disturbances start.

Seventeen adult patients with type 1 diabetes participated. Skin microvascular function in digit IV of the left hand was investigated by laser Doppler fluxmetry (LDF, arbitrary units [AU]). LDF was carried out at rest and following one-min arterial occlusion. Time to peak LDF (s) and percentage increase of LDF (post-occlusive reactive hyperaemia, PRH%) were determined. Retinopathy was assessed from fundus photographs or ophthalmoscopic recordings.

Skin microvascular function remained normal during the first five years. Compared with baseline and a non-diabetic reference group, time to peak LDF was prolonged after 7-9 years of diabetes ( p < 0.01). PRH% was lower than in the reference group after 7-9 years ( p < 0.01), and lower than baseline after 24-29 years of diabetes ( p < 0.05). All but one patient developed retinopathy and the first signs were found after 10 years of diabetes.

Functional disturbances in total skin microcirculation were observed after seven years in patients with type 1 diabetes and preceded diabetic complications such as retinopathy.