Impaired skin microvascular function in children, adolescents, and young adults with type 1 diabetes

OBJECTIVE - Vascular disease in type 1 diabetes is a complex and multifacto rial process, which probably begins in childhood in association with the on set of diabetes. To determine the possible factors involved, we measured mi crovascular responses to endothelium-dependent (acetylcholine) and endothel ium-independent (sodium nitroprusside) vasodilators in 56 patients with typ e 1 diabetes (aged 9-22 years) and 22 control subjects. RESEARCH DESIGN AND METHODS - skin perfusion was measured at the dorsum of the foot using laser Doppler flowmetry during low-current iontophoresis of acetylcholine and sodium nitroprusside. Maximum vasodilator function was me asured during local 44 degrees C skin heating. RESULTS - Vascular responses were significantly reduced in patients with ty pe 1 diabetes compared with responses in control subjects: acetylcholine (P < 0.01, analysis of variance [ANOVA]), sodium nitroprusside (P < 0.01, ANO VA), and local heating (P < 0.02. Mann-Whitney U lest). Endothelium-depende nt responses were related to duration of diabetes (r = -0.38, P < 0.01) and to glycemic control (r = -0.37, P < 0.01). significant correlations were f ound in the patient group between responses to acetylcholine and sodium nit roprusside (r = 0.28, P < 0.05) bur not to heating, suggesting that a commo n factor (e.g., nitric oxide activity) may be responsible for the abnormal vascular responses to these chemicals. CONCLUSIONS - Early changes in microvascular function are present in young patients with type 1 diabetes, long before the initial clinical presentatio n. These abnormalities may be related to complex interactions between struc tural abnormalities and functional changes in the endothelium, smooth muscl e, and nitric oxide activity.