title: Abnormalities of ascorbic acid metabolism and diabetic control: differences between diabetic patients and diabetic rats.
abstract: Ascorbic acid is required in the synthesis of collagen and is also an important anti-oxidant. In a previous study, plasma ascorbic acid concentration was found to be decreased in diabetic patients but there was no relationship with blood glucose level. In the current study of diabetic patients, both plasma ascorbic acid and its urinary excretion correlated inversely with glycosylated hemoglobin level. Plasma ascorbic acid was also lower in diabetic rats but urinary ascorbic acid was elevated. The divergent trend in urinary ascorbic acid excretion observed in diabetic patients and diabetic rats may be due to difference in the ability of these two species to synthesize ascorbic acid. Difference in renal reabsorption of ascorbic acid may also be a relevant factor. The lower plasma and urinary ascorbic acid levels in diabetic patients with more severe hyperglycaemia indicates that this group of patients is particularly at risk of developing deficiency of this vitamin. As ascorbic acid has many important functions in the body, it may be necessary to supplement this vitamin in patients with chronically poorly controlled diabetes.
authors.affiliation: Department of Medicine, University of Sydney, NSW, Australia.
authors.forename: D K
authors.initials: DK
authors.lastname: Yue
authors.forename: S
authors.initials: S
authors.lastname: McLennan
authors.forename: M
authors.initials: M
authors.lastname: McGill
authors.forename: E
authors.initials: E
authors.lastname: Fisher
authors.forename: S
authors.initials: S
authors.lastname: Heffernan
authors.forename: C
authors.initials: C
authors.lastname: Capogreco
authors.forename: J R
authors.initials: JR
authors.lastname: Turtle
mesh_terms: D000328:Adult; D000818:Animals; D001205:Ascorbic Acid / Q000097:blood / Q000378:metabolism* / Q000652:urine; D003920:Diabetes Mellitus / Q000097:blood / Q000378:metabolism* / Q000652:urine; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism* / Q000652:urine; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D008875:Middle Aged; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001205:Ascorbic Acid