Prolonged antioxidant vitamin E and /or C supplementation could be effective to improve endothelial function in non-obese T2DM subjects
Controversy exists among trials assessing whether prolonged antioxidant vitamin supplementation improves endothelial function in type 2 diabetes mellitus ( T2DM ) subjects .
The aim of this study was to systematic ally review and quantify the effect of antioxidant vitamin supplementation on endothelial function in T2DM subjects .
Oral antioxidant therapy improves endothelial function in Type 1 but not Type 2 diabetes mellitus.
Oxidative stress decreases the bioavailability of endothelium-derived nitric oxide in diabetic patients . We investigated whether impaired endothelium-dependent vasodilation ( EDV ) in diabetes can be improved by long-term administration of oral antioxidants .  Forty-nine diabetic subjects [ 26 Type 1 ( T1 ) and 23 Type 2 ( T2 ) ] and 45 matched healthy control subjects were r and omized to receive oral vitamin C ( 1,000 mg ) and vitamin E ( 800 IU ) daily or matching placebo for 6 mo . Vascular ultrasonography was used to determine brachial artery EDV and endothelium-independent vasodilation ( EIV ) . EDV was decreased in both T1 ( 4.9 + /- 0.9 % , P = 0.015 ) and T2 ( 4.1 + /- 1.0 % , P < 0.01 ) subjects compared with control subjects ( 7.7 + /- 0.7 % ) . EIV was decreased in T2 ( 15.0 + /- 1.2 % , P < 0.01 ) but not T1 subjects ( 18.5 + /- 2.3 % , P = 0.3 ) compared with controls ( 21.8 + /- 1.8 % ) . Administration of antioxidant vitamins increased EDV in T1 ( by 3.4 + /- 1.4 % , P = 0.023 ) but not T2 subjects ( by 0.5 . + /- 0.4 % , P = 0.3 ) . Antioxidant therapy had no significant affect on EIV .  Oral antioxidant therapy improves EDV in T1 but not T2 diabetes . These results are consistent with the lack of clinical benefit in studies that have included primarily T2 diabetic patients
Prolonged antioxidant vitamin E and /or C supplementation could be effective to improve endothelial function in non-obese T2DM subjects
Controversy exists among trials assessing whether prolonged antioxidant vitamin supplementation improves endothelial function in type 2 diabetes mellitus ( T2DM ) subjects .
The aim of this study was to systematic ally review and quantify the effect of antioxidant vitamin supplementation on endothelial function in T2DM subjects .