Effects of vitamin C supplementation on antioxidants and lipid peroxidation markers in elderly subjects with type 2 diabetes.
The objective of our study was to evaluate the effects of the administration of two dosages of vitamin C (Vit-C) (0.5 and 1g/day, vs. placebo) in elderly patients with type 2 diabetes mellitus on the intracellular levels of Vit-C and glutathione, and on the lipid peroxidation markers and vitamin E (Vit-E) content of low-density lipoprotein (LDL) and on LDL susceptibility to gamma radiolysis-induced peroxidation. Thirty-six patients were randomized into three groups. In patients on 0.5 g Vit-C/day versus the placebo group, a significant increase in cellular reduced glutathione level was observed (0.60+/-0.26 vs. 0.33+/-0.27). In patients on 1 g Vit-C/day versus placebo, a significant increase was also observed in cellular reduced glutathione (0.93+/-0.70 vs. 0.33+/-0.27), in Vit-C (5.66+/-2.00 vs. 2.72+/-1.88) and in vitamin E content of LDL (1.98+/-0.38 vs. 1.48+/-0.40). No change was observed in either group in basal levels of lipid peroxidation markers and in the susceptibility of LDL to peroxidation provoked by gamma-radiolysis. In conclusion, Vit-C has a dose-dependent effect on the cellular contents of antioxidants and on vitamin E content of LDL in elderly patients with type 2 DM. These changes are not sufficient to decrease the LDL susceptibility to peroxidation.
Tessier
Daniel M
DM
Biogerontology Laboratory, Research Center on Aging, Sherbrooke Geriatric University Institute, 375 Rue Argyll, Sherbrooke, QC J1J 3H5, Canada. dtessier.csss-iugs@ssss.gouv.qc.ca
Khalil
Abdelouahed
A
Trottier
Lise
L
Fülöp
Tamas
T
D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D018384:Oxidative Stress / Q000502:physiology; D016896:Treatment Outcome; D014815:Vitamins / Q000008:administration & dosage*
D000975:Antioxidants; D015415:Biomarkers; D008074:Lipoproteins; D014815:Vitamins; D001205:Ascorbic Acid