The Impact of Preoperative BMI (Obesity Class I, II, and III) on the 12-Month Evolution of Patients Undergoing Laparoscopic Gastric Bypass

Abstract

Whether or not the initial body mass index (BMI) influences weight loss and comorbidities improvement after bariatric surgery continues to be a matter of debate. The main reason for this is a lack of studies including obesity class I. Retrospective study with patients submitted to gastric bypass at a single institution. They were classified based on initial BMI (obesity class I, II, and III), and a comparative analysis of their metabolic profile (glucose, HbA1c%, C-peptide, insulin and diabetes medication), lipid profile (triglycerides, total cholesterol, HDL, LDL), and clinical data (systolic/diastolic blood pressure and cardiovascular risk) was performed at 0 and 12months. Diabetes remission and weight loss were also analyzed. Two-hundred and twenty patients were included (23 in group 1, 113 in group 2, and 84 in group 3). Initial weight, BMI, and number of patients with T2DM were statistically different in group 1; other parameters were homogenous. At 12months, every group had similar improvement of the metabolic profile, excepting serum insulin. Diabetes remission was 57.9, 61.1, and 60% for group 1, 2, and 3. For weight loss, there were differences between groups when using BMI and percentage of excess weight loss, but not with percentage of total weight loss. The non-metabolic and clinical data improved without differences, except for total cholesterol and LDL. The metabolic, lipid, and clinical profiles associated with obesity present similar improvement 1year after laparoscopic gastric bypass, despite different baseline BMI. Diabetes remission and percentage of total weight loss were also similar.