Effect of vitamin E on aminotransferase levels and insulin resistance in children with non-alcoholic fatty liver disease

Background Few data are available on the effect of antioxidants in paediatric nonalcoholic fatty liver disease (NAFLD). Aim To compare the effect of a nutritional programme alone or combined with alpha-tocopherol and ascorbic acid on alanine aminotransferase (ALT) levels, and insulin resistance (IR) in biopsy-proven NAFLD children. Methods In a 12-month double-blind placebo study, 90 patients were prescribed a balanced calorie diet (25-30 cal/kg/d), physical exercise, and placebo (group A) or alpha-tocopherol 600 IU/day plus ascorbic acid 500 mg/ day (group B). IR was estimated by the homeostasis model assessment (HOMA-IR). Results At month 12, ALT (32.67 +/- 8.09 vs. 32.18 +/- 11.39 IU/L; P=NS), HOMA-IR (1.52 +/- 0.66 vs. 1.84 +/- 0.95 IU/L; P=NS), and weight loss (32% vs. 35% of excessive body weight; P=NS) did not differ between the two arms. Among subjects who lost >= 20% of their excessive weight, ALT and body weight percentage changes were significantly related (r(o)=0.260; P=0.03). In subjects, who lost more than 1.0 kg, HOMA-IR significantly decreased (2.20 +/- 0.21 to 1.57 +/- 0.13 in group A (P <= 0.01;-8%); 2.91 +/- 0.24 to 1.88 +/- 0.16 in group B (-32%; P <= 0.0001)). ALT decreased by 36% (59.13 +/- 4.11 vs. 30.27 +/- 1.46 IU/L; P <= 0.001), and 42% (68.19 +/- 5.68 vs. 31.92 +/- 1.92 IU/L; P <= 0.0001). In a multivariate analysis, fasting insulin changes in group A (P=0.012; F=7.150). Conclusions Diet and physical exercise in NAFLD children seem to lead to a significant improvement of liver function and glucose metabolism beyond any antioxidant therapy.