Effects of vitamin E treatment on peroxisome proliferator-activated receptor-α expression and insulin resistance in patients with non-alcoholic steatohepatitis: results of a pilot study
Insulin resistance (IR) is commonly associated with non-alcoholic steatohepatitis (NASH). Peroxisome proliferator-activated receptor-α (PPAR-α) may also play a role in the pathogenesis of NASH. A pivotal role in NASH pathogenesis depends on the hypothesis of increased oxidative stress. The aim of our study was to evaluate the effects of supplemental oral vitamin E, a potent antioxidant, on liver functions, PPAR-α expression and IR in patients with NASH. Methods:
Nine patients with biopsy-proven NASH were given oral vitamin E 800 mg daily for 24 weeks. Liver functions, lipid parameters, IR index with homeostatic metabolic assessment and liver histology and PPAR-α staining index in biopsy specimens were detected before and after the treatment. Results:
Seven patients (78%) had IR initially. After 6 months of therapy in nine patients, fasting insulin improved (P = 0.01), but serum cholesterol, triglyceride, fasting blood glucose levels and body mass index remained unchanged. Aspartate aminotransferase and alanine aminotransferase levels decreased (P = 0.01 and P = 0.01, respectively). IR index with homeostatic metabolic assessment resistance improved (P = 0.01), but PPAR-α staining index did not change (P = 0.37). Although the histological grade of steatosis decreased (P = 0.01), necroinflammation and fibrosis remained unchanged. In seven patients with IR, however, necroinflammation and PPAR-α staining index were improved (P = 0.04 and P = 0.02). Conclusion:
Vitamin E treatment, in addition to its previously shown beneficial effect by suppressing oxidative stress, may also achieve improvement by reducing IR and PPAR-α expression in NASH.
Document Type: Research Article
Affiliations: 1: Department of Internal Medicine, Division of Gastroenterology, University of Kirikkale, School of Medicine, Kirikkale 2: Departments of Pathology 3: Division of Endocrinology and Metabolism, Ministry of Health, Ankara Atatürk Education and Research Hospital, Ankara, Turkey 4: Internal Medicine, Division of Gastroenterology, University of Ankara, School of Medicine 5: Internal Medicine, Division of Gastroenterology, Gazi University, School of Medicine
Publication date: 2007-04-01