Influence of puberty on endothelial dysfunction and oxidative stress in young patients with type 1 diabetes

OBJECTIVE - To examine the influence of puberty on endothelial dysfunction and oxidative stress in children and young people with type 1 diabetes. RESEARCH DESIGN AND METHODS - There were 51 young patients with type 1 diabetes, including 12 prepubertal children, 16 adolescents, and 23 young adults who had no clinical diabetic angiopathy, studied; none had microalbuminuria. The three groups were marched for glycemic control, and systolic and diastolic blood pressures and cholesterol levels were not significantly different between the groups. Endothelium-dependent vasodilatation was assessed by laser Doppler flowmetry after iontophoresis of acetylcholine (ACh) to the skin of the dorsum of the right foot. Soluble E-selectin, intercellular cell adhesion molecule-1 (ICAM-1), von Willebrand factor (vWF), plasma thiol (PSH), red cell glutathione (GSH), and red cell superoxide dismutase (SOD) were measured in blood samples obtained in the early morning. RESULTS - Skin vascular responses to ACh were significantly reduced in the young adult group compared with the prepubertal group (P < 0.05, analysis of variance). The levels of soluble ICAM-1 and E-selectin were significantly higher in the adolescent group compared with the young adult group: 338 (267-415) and 89 (64-106) ng/ml (median [interquartile range]), respectively, versus 255 (222-284) and 58 (54-71) ng/ml (P < 0.01 and P < 0.005, Mann-Whitney U test). SOD levels were significantly higher in the prepubertal group at 250 (238-282) mu/ml, when compared with the adolescent, 217 (171-249) mu/ml (P < 0.04), and young adult, 217 (157-244) mu/ml (P < 0.02), groups. GSH tended to be lower in the adolescent group, 1,192 (1,047-1,367) mu mol/l, when compared with the young adults, 1,286 (1,145-1,525) mu mol/l, and levels of VWF tended to be higher in the adolescent group, bur these failed to reach statistical significance (both P = 0.09). PSH was not different between the three groups. CONCLUSIONS - These results suggest that puberty modulates endothelial function and antioxidant mechanisms in childhood diabetes, which may have implications for therapy and intervention.