Details

Autor(en) / Beteiligte

• MANNING, Patrick J
• SUTERLAND, Wayne H. F
• WALKER, Robert J
• WILLIAMS, Sheila M
• DE JONG, Sylvia A
• RYALLS, Anne R
• BERRY, Elizabeth A

Titel

Effect of High-Dose Vitamin E on Insulin Resistance and Associated Parameters in Overweight Subjects

Ist Teil von

• Diabetes care, 2004-09, Vol.27 (9), p.2166-2171

Ort / Verlag

Alexandria, VA: American Diabetes Association

Erscheinungsjahr

2004

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Effect of High-Dose Vitamin E on Insulin Resistance and Associated Parameters in Overweight Subjects Patrick J. Manning , MMEDSC, FRACP 1 , Wayne H.F. Sutherland , PHD 1 , Robert J. Walker , MD, FRCP 1 , Sheila M. Williams , MSC 2 , Sylvia A. de Jong 1 , Anne R. Ryalls 1 and Elizabeth A. Berry 1 1 Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand 2 Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand Address correspondence and reprint requests to Dr. Patrick J. Manning, Department of Medical and Surgical Sciences, University of Otago, Private bag, Dunedin, New Zealand. E-mail: patrickmanning{at}healthotago.co.nz Abstract OBJECTIVE —Markers of oxidative stress and plasma alanine transferase (ALT) levels are increased and circulating antioxidant concentrations are reduced in individuals with insulin resistance. Vitamin E improves glycemic control in people with diabetes. We tested the hypothesis that vitamin E would decrease markers of oxidative stress and plasma ALT levels and improve insulin sensitivity in overweight individuals. RESEARCH DESIGN AND METHODS —Eighty overweight individuals (BMI >27 kg/m 2 ) were randomly allocated to receive either 800 IU vitamin E per day or a matching placebo for 3 months. The dose of vitamin E was increased to 1,200 IU per day for a further 3 months. RESULTS —Plasma peroxides decreased by 27% at 3 months and by 29% at 6 months in the group that received vitamin E and were positively correlated with plasma vitamin E concentrations at the 6-month time point. At 3 months, fasting plasma glucose and insulin concentrations were significantly reduced and homeostasis model assessment increased. These changes were not apparent at 6 months. Plasma ALT concentrations declined significantly throughout the study period. CONCLUSIONS —In conclusion, these findings indicate that vitamin E improves oxidative stress and hepatocellular function. Although insulin resistance also improves, this effect appears transient. ALT, alanine transferase AST, aspartate aminotransferase CRP, C-reactive protein FFA, free fatty acid GGT, γ-glutamyl transferase HOMA, homeostasis model assessment IL, interleukin ROS, reactive oxygen species TNF, tumor necrosis factor Footnotes A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances. Accepted June 15, 2004. Received April 4, 2004. DIABETES CARE