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
Article first published online: 27 MAR 2007
2007 Royal Australasian College of Physicians
Internal Medicine Journal
Volume 37, Issue 4, pages 229–235, April 2007
How to Cite
Yakaryilmaz, F., Guliter, S., Savas, B., Erdem, O., Ersoy, R., Erden, E., Akyol, G., Bozkaya, H. and Ozenirler, S. (2007), 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. Internal Medicine Journal, 37: 229–235. doi: 10.1111/j.1445-5994.2006.01295.x
Potential conflicts of interest: None
- Issue published online: 27 MAR 2007
- Article first published online: 27 MAR 2007
- Received 16 March 2006; accepted 14 June 2006.
- non-alcoholic steatohepatitis;
- insulin resistance;
- peroxisome proliferator-activated receptor-α;
- vitamin E
Background: 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.