Metformin is effective in achieving biochemical response in patients with nonalcoholic fatty liver disease (NAFLD) not responding to lifestyle interventions

Background: Insulin resistance plays an important role in the pathogenesis of NAFLD. Pharmacological treatment of patients with NAFLD is still evolving. Insulin sensitizing drugs like metformin may be effective in these patients. Twenty five adult patients with NAFLD who did not achieve normalization of alanine transaminases (ALT) after 6 months of lifestyle interventions and UDCA were treated with metformin 500mg tid for 6 months. Insulin resistance was determined by HOMA- IR. Liver function tests were done monthly and patients were defined having no response, partial response or complete biochemical response depending on the change in ALT. Results were compared with 25 patients with NAFLD from the same cohort treated only with lifestyle interventions (disease controls). Results: Thirteen (52%) patients had class III (n = 5) or class IV (n = 8) disease amounting to histological NASH. Of these 13 patients none had severe inflammation and none had stage 4 fibrosis (cirrhosis). All 25 patients with NAFLD had insulin resistance in comparison to healthy controls. In comparison to disease controls (127.5 +/- 41.8 vs. 118 +/- 21.6 p = NS), all patients treated with metformin had partial biochemical response (mean ALT 122.2 +/- 26.8 vs 74.3 +/- 4.2 p < 0.01) and 14 (56%) of them achieved complete normalization of ALT. Conclusions: Metformin is effective to achieve biochemical response in patients with NAFLD who do not respond to lifestyle interventions and UDCA.