Change of Adipose Tissues and Triglyceride in Obese Patients With Non-alcoholic Fatty Liver Disease After Bariatric Surgery or Life-style Intervention

Obesity is associated with different chronic disorders such as metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and diabetes mellitus type 2 (DM2). It can be classified into mild, moderate and severe using different cut-off values of body mass index (BMI). Many interventions and treatments against obesity have been proposed. Patients with mild to moderate obesity are suggested to undergo lifestyle monitoring or intervention programs while patients with severe or morbid obesity may be suggested to undergo bariatric surgery. Brown adipose tissue (BAT) is a specific type of adipose tissue with unique ability to produce heat by non-shivering thermogenesis. It increases energy expenditure and lower blood glucose levels and therefore it is suggested to be a potential therapy against obesity, NAFLD, DM2 etc.

Research studies demonstrated that obesity is strongly associated with NAFLD. From our previous observation, most obese individuals suffer from NAFLD. Nevertheless, a small portion of them are protected from NAFLD. We try to understand why and how this small portion of severe obese patients can keep themselves protected from NAFLD while some lean individual suffers from it. We would also like to test whether the amount of BAT is a biomarker for NAFLD. Besides, we would like to validate the accuracy of liver inflammation and fibrosis (LIF) scores with liver biopsy results.

The change of adipose tissues (i.e. brown, subcutaneous, visceral), triglyceride in liver and pancreas and cholesterol (i.e. HDL and LDL) in bloodstream would be measured in patients with NAFLD who undergo either bariatric surgery or lifestyle intervention. 40 subjects will be recruited. Half of them for the lifestyle intervention group while half for the bariatric group. Baseline MRI and blood test will be performed before the start of their treatments and two follow-up scans as well as blood tests in six-month and twelve-month intervals.

This study allows objective measurement to evaluate efficacy of different treatments against obesity and the response of NAFLD after weight loss. Furthermore, this study provides quantitative measurement of BAT and tests whether BAT is associated with NAFLD or other metabolites disorders such as DM2 and hyperlipidemia.

b) Research plan and methodology Subjects Eighty volunteers will be recruited for this project. 40 of them with mild-moderate obesity and the other 40 subjects with morbid obesity.