Serum alpha-tocopherol and ascorbic acid concentrations in Type 1 and Type 2 diabetic patients with and without angiopathy.
BACKGROUND
Alpha-tocopherol and ascorbic acid form a part of scavenger system influencing the level of oxidative stress in diabetes mellitus. The aim of this study was to evaluate serum concentrations of alpha-tocopherol and ascorbic acid in Type 1 and Type 2 diabetes mellitus and to compare them with the presence of vascular complications as well as with oxidative stress and endothelial dysfunction.


METHODS
A total of 38 Type 1 and 62 Type 2 diabetic patients were subdivided into those with and without angiopathy. Serum alpha-tocopherol and ascorbic acid concentrations were estimated in all patients and in 38 healthy persons. Their results were compared with diabetes control, with oxidative stress measured by plasma malondialdehyde and with endothelial dysfunction estimated by serum N-acetyl-beta-glucosaminidase activity. In addition, the differences in biochemical variables were compared between patients with and without angiopathy.


RESULTS
Serum alpha-tocopherol related to the sum of cholesterol and triglyceride concentrations (AT/CHT ratio) was significantly lower in diabetic patients with macroangiopathy than in those without vascular changes (p<0.05). Serum ascorbic acid levels were significantly lower only in Type 2 diabetic patients with macroangiopathy as compared with healthy controls as well as with patients without vascular disease (p<0.01). Positive relationship was observed between serum alpha-tocopherol and cholesterol or triglyceride concentrations in both Type 1 and Type 2 diabetic patients. The presence of oxidative stress together with endothelial dysfunction measured by N-acetyl-beta-glucosaminidase activity was accompanied by lower AT/CHT ratio (p<0.005) in Type 2 diabetic patients.


CONCLUSIONS
Diabetic patients with proven angiopathy or with advanced oxidative stress and endothelial dysfunction have significantly lower AT/CHT ratio and ascorbic acid concentration in serum. Their low concentrations may participate at the increased level of oxidative stress in these individuals.
Skrha
Jan
J
Laboratory for Endocrinology and Metabolism, Department of Internal Medicine 3, Faculty of Medicine 1, Charles University, Prague, Czech Republic. jan.skrha@lfl.cuni.cz
Prázný
Martin
M
Hilgertová
Jirina
J
Weiserová
Hana
H
D000117:Acetylglucosamine / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood*; D002784:Cholesterol / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D003925:Diabetic Angiopathies / Q000097:blood*; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress / Q000502:physiology; D012709:Serum Albumin / Q000032:analysis / Q000378:metabolism; D014280:Triglycerides / Q000097:blood; D014810:Vitamin E / Q000097:blood*
D000975:Antioxidants; D008055:Lipids; D012709:Serum Albumin; D014280:Triglycerides; D014810:Vitamin E; D008315:Malondialdehyde; D002784:Cholesterol; D001205:Ascorbic Acid; D000117:Acetylglucosamine