Clinical trial NCT00063232
Conditions: Hepatitis
Keywords: Insulin Obesity Fatty Liver Diabetes Cirrhosis Metformin Insulin Resistance Nonalcoholic Steatohepatitis Hepatitis NASH
Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Start date: 2003-06-01; Completion date: 2008-03-01
Enrollment: 28 participants; Allocation: ; Intervention model: 

Brief summary:
Nonalcoholic Steatohepatitis (NASH) is associated with progressive liver disease, fibrosis, and cirrhosis. Although the cause of NASH is unknown, it is often associated with obesity, type 2 diabetes, and insulin resistance. At present, there are no approved treatments for NASH patients, but an experimental approach has focused on improving their insulin sensitivity. Metformin is one of the most commonly used medications for the treatment of diabetes.

The purpose of this study is to determine whether the medical problems of NASH patients, specifically liver damage, improves when their insulin sensitivity is enhanced with metformin.

The study will last 3 to 5 years and will enroll up to 30 patients. Participants will undergo a complete medical examination, a series of lab tests, and a liver biopsy. They will then start taking a single 500-mg tablet of metformin once a day for 2 weeks, then the same dosage twice a day for 2 more weeks, if they tolerate the first dosage. The dosage will increase to 1,000 mg twice a day for the remaining 44 weeks of the study. After 1 year, participants will undergo a repeat medical examination and liver biopsy.

Detailed description:
Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of diseases ranging from simple fatty liver (steatosis) to steatosis with inflammation and necrosis to cirrhosis, that occurs in persons who drink little or no alcohol. Nonalcoholic steatohepatitis (NASH) represents the more severe end of this spectrum and is associated with progressive liver disease, fibrosis and cirrhosis. The etiology of NASH is unclear, but it is often associated with obesity, type 2 diabetes, hyperlipidemia and insulin resistance. We have recently conducted a study of a 48-week course of pioglitazone in 21 non-diabetic patients with NASH. Serum aminotransferase levels and liver histology improved in most patients and the improvements correlated with changes in insulin sensitivity. These results are promising, but pioglitazone is associated with significant weight gain, is quite expensive, and its long-term safety is yet to be proven. In contrast, metformin is inexpensive, extremely well tolerated, and of proven long-term safety in patients with diabetes and pre-diabetes.

In this study, we propose to treat 20 non-diabetic patients with NASH with metformin for 48-weeks. After an initial evaluation for insulin sensitivity, fat distribution and liver biopsy, patients will receive gradually increasing doses of metformin orally to a maximum of 2000 mg daily. Patients will be monitored at regular intervals for symptoms of liver disease, side effects of metformin and serum biochemical and metabolic indices. At the end of 48-weeks, patients will have a repeat medical evaluation and liver biopsy. Pre and post treatment liver histology, fat distribution and insulin sensitivity will be compared. The primary end point of successful therapy will be improvement in hepatic histology as determined by reduction of at least three points in NASH activity score. Secondary end points will be improvement in insulin sensitivity, body fat distribution, and liver biochemistry.

Interventions: intervention 1: Metformin
Intervention descriptions: intervention 1: After complete medical evaluation and liver biopsy, patients who qualified for therapy were started on metformin in an initial dose of 500 mg once daily. After 2 weeks, the dose was increased to 500 mg twice daily and after 4 weeks to the full dose of 1000 mg twice daily. Subsequent dose reductions were carried out based on tolerance, with particular attention to gastrointestinal upset and abdominal bloating. Patients were seen in the out-patient clinic, had a brief medical history and examination and routine blood tests at 2 and 4 weeks after enrolment and every 4 weeks thereafter. The oral and intravenous glucose tolerance tests were repeated after 40 and 44 weeks respectively and liver biopsy and imaging tests at 48 weeks. Metformin was discontinued after 48 weeks in patients without diabetes on the pre-treatment evaluation.

Protocol documents: