A pilot study of a 48-week course of pioglitazone demonstrated significant improvements in the biochemical and histological features of nonalcoholic steatohepatitis (NASH). The aim of the study was to assess the effects of stopping pioglitazone. Twenty-one patients with NASH were treated with pioglitazone (30 mg/day) for 48 weeks and underwent baseline and end-of-treatment evaluation including liver biopsy. Thirteen patients were followed for at least 48 weeks after stopping therapy and 9 underwent repeat liver biopsy. Statistical comparisons were made to evaluate whether discontinuation of pioglitazone resulted in a reversal of improvements seen on therapy. Stopping pioglitazone was associated with subsequent elevation in serum alanine aminotransferase levels (from 34 +/- 13 to 70 +/- 39 IU/l), decrease in adiponectin (from 9.7 +/- 9.1 to 5.1 +/- 4.5 microg/ml), worsening insulin sensitivity (HOMA Index: from 2.9 +/- 1.8 to 5.5 +/- 5.4), and increase in total hepatic fat (from 30% +/- 32% to 71% +/- 33%) despite no change in average body weight compared to the end of treatment. Repeat liver biopsy in 9 patients revealed significant worsening of parenchymal inflammation (from 1.2 +/- 0.7 to 2.9 +/- 1.1) and steatosis (from 0.9 +/- 0.6 to 2.1 +/- 1.3) but no change in fibrosis (from 1.1 +/- 1.2 to 1.2 +/- 1.3). NASH was again present on liver biopsy in 7 patients.
Conclusion: These findings suggest that long-term therapy with pioglitazone may be necessary to maintain improvements in disease activity in patients with NASH, although weight gain during treatment may ultimately limit its beneficial effects.