Effects of Ursodeoxycholic Acid on Hepatobiliary Detoxification/Elimination Mechanisms and Hepatic Fatty Acid/Triglyceride Metabolism in Morbidly Obese Patients.

In an open-label trial, 20 otherwise healthy morbidly obese patients scheduled for bariatric surgery will be administered 20 mg/kg/day ursodeoxycholic acid for three weeks until the day before surgery. The maximum dose will be 3 g/day. Twenty other patients will serve as controls. Serum from days 1 and 21 will be analyzed for routine liver tests, bile acids, a complete lipid profile including FA and in addition for 7α-hydroxy-4-cholesten-3-one and fibroblast growth factor 19 (FGF-19), markers for bile acid synthesis its intestinal stimulation. For the evaluation of insulin resistance and possible pre-diabetes, plasma will be taken for the estimation of homeostasis model assessment (HOMA) index and oral glucose tolerance test (OGTT) will be performed at days 1 and 21. At surgery, a liver biopsy (0.5-1 g) and a white adipose tissue (WAT) specimen (1 cm2) will be taken and immediately frozen in liquid nitrogen for messenger ribonucleic acid (mRNA) and protein preparation for quantitative real-time polymerase chain reaction (RT-PCR) and Western analysis, respectively, histopathological Non-alcoholic fatty liver disease (NAFLD) grading, and measuring of hepatic and white adipose tissue (WAT) lipase activity. In all patients at randomization, abdominal ultrasound will be performed for the detection of NAFLD and gallstones and a blood sample will be taken for the analysis of polymorphisms of hepatic lipid synthesis, storage, fatty acid (FA) oxidation and export genes. Six month after operation, HOMA, OGTT and abdominal ultrasound will be repeated.