The effects of lipoic acid and α-tocopherol supplementation on the lipid profile and insulin sensitivity of patients with type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled trial

• Published in: Diabetes research and clinical practice 2011-05, Vol.92 (2), p.253-260
• Main Authors: de Oliveira, Andreia Madruga, Rondó, Patrícia Helen Carvalho, Luzia, Liania Alves, D’Abronzo, Francisco Homero, Illison, Vanessa Kristine
• Format: Article
• Language: English
• Subjects: Adult; Aged; alpha-Tocopherol - therapeutic use; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - drug therapy; Dietary Supplements; Double-Blind Method; Endocrinology & Metabolism; Female; Humans; Insulin - blood; Insulin resistance; Lipids - blood; Lipoic acid; Male; Metabolic syndrome; Middle Aged; Thioctic Acid - therapeutic use; Type 2 diabetes mellitus; Vitamin E
• ISSN: 0168-8227; 1872-8227
• DOI: 10.1016/j.diabres.2011.02.010

Abstract Antioxidants probably play an important role in the etiology of type 2 diabetes (DM2). This study evaluated the effects of supplementation with lipoic acid (LA) and α-tocopherol on the lipid profile and insulin sensitivity of DM2 patients. A randomized, double-blind, placebo-controlled trial involving 102 DM2 patients divided into four groups to receive daily supplementation for 4 months with: 600 mg LA ( n = 26); 800 mg α-tocopherol ( n = 25); 800 mg α-tocopherol + 600 mg LA ( n = 25); placebo ( n = 26). Plasma α-tocopherol, lipid profile, glucose, insulin, and the HOMA index were determined before and after supplementation. Differences within and between groups were compared by ANOVA using Bonferroni correction. Student's t -test was used to compare means of two independent variables. The vitamin E/total cholesterol ratio improved significantly in patients supplemented with vitamin E + LA and vitamin E alone ( p ≤ 0.001). There were improvements of the lipid fractions in the groups receiving LA and vitamin E alone or in combination, and on the HOMA index in the LA group, but not significant. The results suggest that LA and vitamin E supplementation alone or in combination did not affect the lipid profile or insulin sensitivity of DM2 patients.