Weight loss outcomes in obese patients undergoing Laparoscopic Sleeve Gastrectomy

This study is an observational cohort study of weight loss outcomes in patients undergoing Laparoscopic Sleeve Gastrectomy (LSG) procedure at the Gold Coast Private Hospital. Participants will undertake baseline testing approximately 4 weeks prior to their scheduled LSG procedure. This data will represent the patients baseline before weight loss. Two weeks prior to the LSG procedure, all participants (regardless of their involvement in the present study) will begin a pre-operative weight loss intervention as required by Dr Victor Liew. This period involves a very low calorie diet (VLCD) which helps patients lose visceral fat and reduce the size of the fatty liver, making surgery safer and often leads to a better surgical outcome. A second baseline analysis will occur approximately one week prior to the LSG procedure, to account for any changes which may have occurred between baseline testing and the VLCD. Three months post-LSG procedure, participants will undergo all testing, as they did at baseline. These tests will be repeated at 6, 12, 24 months post-operative and each year up to 5 years post-surgery. The information gained on percentage of weight loss during the initial 2-3 months post-surgery will inform the research team as to which participants are high or low responders (known as the responder identification period). We will use retrospective data from previous patients who underwent LSG by same surgical team in 2017-2018 to generate weight loss patterns. We will use these patterns to estimate weight loss outcomes of patients and selection for low and high responders to LSG early post-surgery. All participants that are within the top or bottom 10th percentile for percentage of total weight loss will be invited to continue with comprehensive testing and tissue biopsies at the 6, 12 and 24 month post-operative point, and every year thereafter for up to 5 years. All other participants will continue to track weight, changes in medication use, blood pathology for characterisation of presence or absence/resolution of comorbidities (impaired glucose tolerance, diabetes, dyslipidemia, hypertension).