Conditions: Nonalcoholic Steatohepatitis Nonalcoholic Fatty Liver Disease Type 2 Diabetes Mellitus
Keywords: Additional relevant MeSH terms: Hypoglycemic Agents Physiological Effects of Drugs Pharmacologic Actions Pioglitazone
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 176
Healthy volunteers: yes

Brief summary:
Obesity and Type 2 diabetes are creating a silent epidemic, Non-alcoholic fatty liver disease, which is a chronic liver disease associated with insulin resistance, impaired glucose intolerance, and hepatic fat accumulation. The thiazolidinedione pioglitazone improves glucose/lipid metabolism and histology in NASH by improving insulin resistance in the liver/peripheral/adipose tissues and reducing subclinical inflammation. The aim of this study is to assess the underlying mechanisms at the clinical and molecular level and the long-term efficacy and safety of pioglitazone in NASH in a multiethnic cohort of subjects (predominantly Hispanics, Caucasians and African-Americans - the most common ethnic groups locally) and examine the response including patients with normal glucose tolerance, impaired glucose tolerance or established type 2 diabetes mellitus (T2DM).

Detailed description:
NASH is a disease characterized by elevated plasma aminotransferases and histopathological changes in liver characterized by hepatocellular steatosis, chronic inflammation and perisinusoidal fibrosis. NASH affects (\~30-40%) of obese and type 2 diabetic subjects. While the pathogenesis of NASH is poorly understood, there is consensus that insulin resistance and its associated abnormalities in lipid metabolism play a key role in the development of liver fat accumulation. Insulin resistance in nonalcoholic steatohepatitis is frequently associated with chronic hyperinsulinemia, hyperglycemia, and an excessive supply of plasma free fatty acids to the liver. This in turn promotes hepatic lipogenesis. Pioglitazone, a thiazolidinedione (TZD), reverses these abnormalities by ameliorating insulin resistance in adipose tissue, liver and muscle. TZDs decrease excessive ectopic triglyceride accumulation in liver and muscle, reduce visceral fat, and redistribute fat to subcutaneous adipose stores. We have shown in a proof-of-concept 6-month study that pioglitazone is safe and effective for the treatment of T2DM. Patients with nonalcoholic steatohepatitis are also characterized by a low plasma adiponectin level. Thiazolidinediones increase plasma adiponectin levels, may activate AMP-activated protein kinase, stimulate hepatic/muscle fatty acid oxidation, and inhibit hepatic fatty acid synthesis in NASH nonalcoholic steatohepatitis. Thiazolidinediones also have antiinflammatory effects which are believed to be of value for therapy for NASH.

In order to evaluate this hypothesis, the investigators will treat for up to 36 months a group of patients with impaired (IGT) glucose tolerance and T2DM patients recruited from the University Hospital and medical school clinics and by newspaper add targeting the San Antonio and South Texas geographical area, with pioglitazone in a randomized, double-blinded, placebo-controlled trial. The primary endpoint will be liver histologic response assessed by liver biopsy performed at 18 and at 36 months of treatment.

Arms:
arm 1: After all patients receive dietary counseling at the research unit (CTSA), patients with prediabetes or type 2 diabetes mellitus (T2DM) and NASH will be started on pioglitazone (or placebo) in a randomized, double-blind,placebo-controlled study design. Pioglitazone will be given at 30 mg/day for the first 2 months and titrated to 45 mg/day thereafter (if well tolerated). arm 2: After dietary counseling to all patients at the research unit (CTSA), patients with prediabetes or type 2 diabetes mellitus (T2DM) and NASH will be started on pioglitazone (or placebo) in a randomized, double-blind,placebo-controlled study design. Pioglitazone will be given at 30 mg/day for the first 2 months and titrated to 45 mg/day thereafter (if well tolerated).

Interventions: intervention 1: Pioglitazone study drug intervention 2: Placebo intervention 3: Pioglitazone Open Label
Intervention descriptions: intervention 1: 30 mg per day orally for 8 weeks, and if well tolerated, titrated to 45 mg per day until the end of 18 months intervention 2: An oral tablet identical to pioglitazone will be given once daily but without active drug for 18 months. intervention 3: Patients in both arms were placed open label pioglitazone for an additional 18 months after successfully completing the double-blind, placebo-controlled portion of the study design.

Protocol document: