Endocrine Abstracts

Background: Obesity is one of the most critical problems nowadays, its frequency and consequences. Since the risk of morbidity and mortality increases in obese individuals, lifestyle changes, pharmacotherapy, and bariatric surgery (BS) methods are used for treatment. BS is generally considered the most effective method to treat morbid obesity. However, it is known that thyroid function has a role in weight regulation, the effect of preoperative thyroid function on weight loss after BS is not fully understood. Therefore, we aim to evaluate the impact of thyroid function tests and metabolic variables on weight loss after BS.

Methods: The patients who underwent bariatric surgery between 01.12.2014 and 01.06.2020 in our hospital were retrospectively screened. Patients with a history of thyroid disease treated with thyroid hormone or antithyroid drugs were excluded from the study. A total of 635 patients between 18 and 65 years were included, preoperative and postop 1st-year data were recorded, and the percent of total weight loss (%TWL) was calculated, in our study. Patients were divided into two groups in terms of %TWL. Those with %TWL<35 were defined as Group 1, and those with %TWL<35 were defined as Group 2. All parameters were compared between the groups. Regression analysis was applied to evaluate which factors affected postoperative weight loss contributed more to the outcome.

Results: The mean age of 635 patients (154 male/481 female) was 39.3±10.6 years. Age, pre-and postop fasting plasma glucose (FPG), postop ALT levels were significantly higher in Group 1 than Group 2 (P<0.001, P=0.011, P<0.001, P=0.009, respectively). FT3 level was significantly higher in Group 2 than Group 1 (P=0.005). While there was no significant difference between the two groups regarding gender, DM and HT patients were significantly more frequent in Group 1 (P=0.003, P=0.005, respectively). The regression analysis determined that increasing fT3 levels raised the probability of being in %TWL≥35 group by 1.6-fold (OR=1.577, P=0.027).

Conclusion: Weight loss after BS varies according to individuals. Therefore, predicting patients who will respond better to surgery is essential for the clinical management and follow-up of patients with obesity. In this regard, the present study showed that increasing fT3 levels, even if in the normal range, raised the probability of losing weight adequately.