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

To examine the influence of puberty on endothelial dysfunction and oxidative stress in children and young people with type 1 diabetes.

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 matched 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.

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) micro/ml, when compared with the adolescent, 217 (171-249) micro/ml (P < 0.04), and young adult, 217 (157-244) micro/ml (P < 0.02), groups. GSH tended to be lower in the adolescent group, 1,192 (1,047-1,367) micromol/l, when compared with the young adults, 1,286 (1,145-1,525) pmol/l, and levels of vWF tended to be higher in the adolescent group, but these failed to reach statistical significance (both P = 0.09). PSH was not different between the three groups.

These results suggest that puberty modulates endothelial function and antioxidant mechanisms in childhood diabetes, which may have implications for therapy and intervention.