Effects of antioxidant supplementation on insulin sensitivity, endothelial adhesion molecules, and oxidative stress in normal-weight and overweight young adults

Abstract

The objective of the study was to determine whether short-term antioxidant (AOX) supplementation affects insulin sensitivity, endothelial adhesion molecule levels, and oxidative stress in overweight young adults. A randomized, double-blind, controlled study tested the effects of AOXs on measures of insulin sensitivity (homeostasis model assessment [HOMA]) and quantitative insulin sensitivity check index), endothelial adhesion molecules (soluble intercellular adhesion molecule-1, vascular adhesion molecule, and endothelial-leukocyte adhesion molecule-1), adiponectin, and oxidative stress (lipid hydroperoxides) in overweight and normal-weight individuals (N = 48, 18-30 years). Participants received either AOX (vitamin E, 800 IU; vitamin C, 500 mg; beta-carotene, 10 mg) or placebo for 8 weeks. The HOMA values were initially higher in the overweight subjects and were lowered with AOX by week 8 (15% reduction, P = .02). Adiponectin increased in both AOX groups. Soluble intercellular adhesion molecule-1 and endothelial-leukocyte adhesion molecule-1 decreased in overweight AOX-treated groups by 6% and 13%, respectively (P < .05). Plasma lipid hydroperoxides were reduced by 0.31 and 0.70 nmol/mL in the normal-weight and overweight AOX-treated groups, respectively, by week 8 (P < .05). Antioxidant supplementation moderately lowers HOMA and endothelial adhesion molecule levels in overweight young adults. A potential mechanism to explain this finding is the reduction in oxidative stress by AOX. Long-term studies are needed to determine whether AOXs are effective in suppressing diabetes or vascular activation over time.

Figures

Figure 1a

Fasting insulin values for normal weight and overweight young adults treated with antioxidants (AOX, vitamins E, C and β-carotene) or placebo (PL) at baseline and 8 weeks. Values are means ± SE.

Figure 1b

HOMA values for normal weight and overweight young adults treated with antioxidants (AOX, vitamins E, C and β-carotene) or placebo (PL) at baseline and 8 weeks. Values are means ± SE.

Figure 1c

Fasting plasma glucose concentrations for normal weight and overweight young adults treated with antioxidants (AOX, vitamins E, C and β-carotene) or placebo (PL) at baseline and 8 weeks. Values are means ± SE.