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).
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
176
30 mg per day orally for 8 weeks, and if well tolerated, titrated to 45 mg per day until the end of 18 months
An oral tablet identical to pioglitazone will be given once daily but without active drug for 18 months.
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.
Bartter Research Unit, Audie L Murphy VA Hospital
San Antonio, Texas, United States
Liver Histology (Using Kleiner et al Criteria, Hepatology 2005)
Number of patients with reduction of at least 2 points in the nonalcoholic fatty liver disease activity score (NAS) (with reduction in at least 2 different histological categories) without worsening of fibrosis. NAS is the sum of the separate scores for steatosis (0-3), hepatocellular ballooning (0-2) and lobular inflammation (0-3), and ranges from 0-8 . The scoring system is based on the following grading: Steatosis: 0 = \<5%; 1 = 5-33%; 2 = \>33-66%; 3 = \>66%. Lobular Inflammation: 0 = No foci 1 = \<2 foci/200x; 2 = 2-4 foci/200x, 3 = \>4 foci/200x. Hepatocyte Ballooning: 0 = None; 1 = Few balloon cells; 2 = Many cells/prominent ballooning. Fibrosis: 0 = None; 1 = Perisinusoidal or periportal; 2 = Perisinusoidal and portal/periportal; 3 = Bridging fibrosis, 4 = Cirrhosis.
Time frame: At 18 months
Number of Participants With Resolution of NASH
Resolution of NASH was defined as absence of NASH after 18 months of therapy in patients with definite NASH (presence of zone 3 accentuation of macrovesicular steatosis of any grade, hepatocellular ballooning of any degree, and lobular inflammatory infiltrates of any amount) at baseline.
Time frame: Month 18
Mean Individual Histological Scores
Mean change in individual scores compared to baseline. Steatosis: 0 = \<5%; 1 = 5-33%; 2 = \>33-66%; 3 = \>66%. Lobular Inflammation: 0 = No foci 1 = \<2 foci/200x; 2 = 2-4 foci/200x, 3 = \>4 foci/200x. Hepatocyte Ballooning: 0 = None; 1 = Few balloon cells; 2 = Many cells/prominent ballooning. Fibrosis: 0 = None; 1 = Perisinusoidal or periportal; 2 = Perisinusoidal and portal/periportal; 3 = Bridging fibrosis, 4 = Cirrhosis
Time frame: Baseline and Month 18
Individual Histological Scores
Number of patients with improvement of at least 1 grade in each of the histological parameters. Steatosis: 0 = \<5%; 1 = 5-33%; 2 = \>33-66%; 3 = \>66%. Lobular Inflammation: 0 = No foci 1 = \<2 foci/200x; 2 = 2-4 foci/200x, 3 = \>4 foci/200x. Hepatocyte Ballooning: 0 = None; 1 = Few balloon cells; 2 = Many cells/prominent ballooning. Fibrosis: 0 = None; 1 = Perisinusoidal or periportal, 1A = Mild, zone 3, perisinusoidal "delicate" fibrosis; 1B = Moderate, zone 3, perisinusoidal "dense" fibrosis; 1C = Portal/periportal; 2 = Perisinusoidal and portal/periportal; 3 = Bridging fibrosis, 4 = Cirrhosis
Time frame: Month 18
Mean Individual Histological Scores
Steatosis: 0 = \<5%; 1 = 5-33%; 2 = \>33-66%; 3 = \>66%. Lobular Inflammation: 0 = No foci 1 = \<2 foci/200x; 2 = 2-4 foci/200x, 3 = \>4 foci/200x. Hepatocyte Ballooning: 0 = None; 1 = Few balloon cells; 2 = Many cells/prominent ballooning. Fibrosis: 0 = None; 1 = Perisinusoidal or periportal; 2 = Perisinusoidal and portal/periportal; 3 = Bridging fibrosis, 4 = Cirrhosis
Time frame: Month 36
Liver Transaminases (AST and ALT).
Time frame: 18 and 36 months
Liver Fat by Magnetic Resonance and Spectroscopy (MRS).
Liver fat content was calculated as the fat fraction: 100\*(area under the curve \[AUC\] of fat peak / \[AUC of fat peak + AUC of water peak\]).
Time frame: 18 months
Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)
Homeostatic model assessment of insulin resistance (HOMA-IR) is a method for assessing insulin resistance (IR) from basal fasting plasma glucose (FPG) and fasting plasma insulin (FPI). It is calculated as (FPG x FPI)/405.
Time frame: 18 and 36 months
Hepatic Insulin Sensitivity
Suppression of endogenous glucose production (Supp EGP) by low dose insulin (i.e., percentage of reduction of EGP with low dose insulin infusion compared to the baseline state). This was calculated as: 100\*((EGP without insulin - EGP with insulin infusion)/EGP without insulin). All measurements are obtained at the same time point during an euglycemic insulin clamp.
Time frame: 18 months
Adipose Tissue Insulin Sensitivity
Suppression of free fatty acids by low dose insulin (i.e., percentage of reduction of plasma FFA with low dose insulin infusion compared to the baseline state). This was calculated as: 100\*((plasma FFA without insulin - plasma FFA with insulin infusion)/plasma FFA without insulin). All measurements are obtained at the same time point during an euglycemic insulin clamp.
Time frame: 18 months
Skeletal Muscle Insulin Sensitivity
Rate of glucose disappearance (Rd) during high-dose insulin infusion. The rate of plasma glucose disappearance was calculated using Steele's non-steady-state equation.
Time frame: 18 months
Body Mass Index (BMI)
Time frame: Months 18 and 36
Total Body Fat
Total body fat measured by dual-energy x-ray absorptiometry (DXA)
Time frame: Months 18
Plasma Biomarkers Relevant to Hepatic Inflammation, Apoptosis and Fibrosis (Adiponectin).
Time frame: 18 and 36 months
Plasma Biomarkers Relevant to Hepatic Inflammation, Apoptosis and Fibrosis (CK-18).
Time frame: 18 and 36 months
Prevention of the Onset of T2DM and/or Reversal From IFG/IGT to NGT in Non-diabetics.
Number of patients developing T2DM and number of patients regressing to NGT among patients with prediabetes (IFG/IGT).
Time frame: 18 months
Osteoporotic Fractures
Number of patients with osteoporotic fractures
Time frame: 18 and 36 months
Molecular Pathways of Liver Glucose and Lipid Signaling; Inflammatory Pathways; Oxidative Stress; Other.
Time frame: At 18 (2nd liver biopsy) and 36 (3rd liver biopsy) months.
Bone Mineral Density
Bone mineral density measured at the levels of spine, femoral neck, hip, and wrist by DXA.
Time frame: 18 and 36 months
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