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 .
Lack of effect of oral vitamin C on blood pressure, oxidative stress and endothelial function in Type II diabetes.
Type II diabetes is characterized by increased oxidative stress , endothelial dysfunction and hypertension . We investigated whether short-term treatment with oral vitamin C reduces oxidative stress and improves endothelial function and blood pressure in subjects with Type II diabetes . Subjects ( n = 35 ) received vitamin C ( 1.5 g daily in three doses ) or matching placebo for 3 weeks in a r and omized , double-blind , parallel-group design . Plasma concentrations of 8-epi-prostagl and in F(2alpha ) ( 8-epi-PGF(2alpha ) ) , a non-enzymically derived oxidation product of arachidonic acid , were used as a marker of oxidative stress . Endothelial function was assessed by measuring forearm blood flow responses to brachial artery infusion of the endothelium-dependent vasodilator acetylcholine ( with nitroprusside as an endothelium-independent control ) and by the pulse wave responses to systemic albuterol ( endothelium-dependent vasodilator ) and glyceryl trinitrate ( endothelium-independent vasodilator ) . Plasma concentrations of vitamin C  increased from 58+/-6 to 122+/-10 micromol/l after vitamin C , but 8-epi-PGF(2alpha ) levels ( baseline , 95+/-4 pg/l ; after treatment , 99+/-5 pg/l ) , blood pressure ( baseline , 141+/-5/80+/-2 mmHg ; after treatment , 141+/-5/81+/-3 mmHg ) and endothelial function , as assessed by the systemic vasodilator response to albuterol and by the forearm blood flow response to acetylcholine , were not significantly different from baseline or placebo . Thus treatment with vitamin C ( 1.5 g daily ) for 3 weeks does not significantly improve oxidative stress , blood pressure or endothelial function in patients with Type II diabetes
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 .