[Erythrocyte and plasma antioxidant activity in diabetes mellitus type I].
OBJECTIVE
Some biologic parameters involved in cell defence against oxygen radicals (plasmatic vitamins C and E, erythrocyte glutathione peroxidase, glutathione reductase and superoxide dismutase) were measured in single blood samples from 119 diabetic infants, adolescents and young adults.


METHODS
Data were studied in relation to residual insulin secretion determined by C peptide, level of metabolic control appreciated by glycosylated haemoglobin, lipid abnormalities and subclinical complications (retinopathy, neuropathy and nephropathy).


RESULTS
There was no change in antioxidant parameters with insulin secretion. Patients with poor glycaemic control and high plasma lipids had higher levels of plasma vitamin E. Patients with nephropathy had lower plasma vitamin C levels and those with neuropathy showed lower erythrocyte glutathione peroxidase activity. Plasma vitamin C concentrations and erythrocyte glutathione reductase activities were negatively correlated with the age of the patients and the duration of the disease.


CONCLUSIONS
Higher transport capacity of vitamin E probably explains the elevated levels of vitamin E observed in patients with high lipid levels and long lasting illness. The lower levels of vitamin C in the presence of nephropathy may be due to an increased renal excretion of this vitamin. The reduction of glutathione peroxidase, glutathione reductase activities and vitamin C levels confirms the existence of an oxidative stress in type I diabetes.
Ndahimana
J
J
Service de Chimie médicale, Université Libre de Bruxelles, Belgique.
Dorchy
H
H
Vertongen
F
F
D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D003928:Diabetic Nephropathies / Q000097:blood; D003929:Diabetic Neuropathies / Q000097:blood; D003930:Diabetic Retinopathy / Q000097:blood; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male
D000975:Antioxidants
Activité anti-oxydante érythrocytaire et plasmatique dans le diabète de type I.