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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
Author(s) -
Yakaryilmaz F,
Guliter S,
Savas B,
Erdem O,
Ersoy R,
Erden E,
Akyol G,
Bozkaya H,
Ozenirler S
Publication year - 2007
Publication title -
internal medicine journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.596
H-Index - 70
eISSN - 1445-5994
pISSN - 1444-0903
DOI - 10.1111/j.1445-5994.2006.01295.x
Subject(s) - steatohepatitis , medicine , insulin resistance , endocrinology , triglyceride , liver biopsy , fatty liver , steatosis , homeostatic model assessment , biopsy , insulin , cholesterol , disease
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.