The Effect of Laparoscopic Sleeve Gastrectomy on Serum Thyroid-Stimulating Hormone Levels in Obese Patients with Overt and Subclinical Hypothyroidism: a 7-Year Retrospective Study

Background Inconsistent results were reported by several studies that evaluated the effect of weight loss induced by bariatric surgery on thyroid function panel. This study is aimed at evaluating this effect on thyroid-stimulating hormone (TSH) and thyroid hormone replacement dosages in obese population with overt and subclinical hypothyroidism (SH). Methods A retrospective study was performed on all morbidly obese patients with previous diagnosis of overt and subclinical hypothyroidism who underwent laparoscopic sleeve gastrectomy from October 2009 to January 2017. The correlation between TSH and body mass index (BMI) and the effect of weight loss induced by bariatric surgery on TSH were investigated. Results The prevalence of overt and SH in morbidly obese patients was 10.8% and 7.2%, respectively. Thirty-six hypothyroid patients and 67 subclinically hypothyroid patients were included in the study. Hypothyroidism improved in 44.5% of patients and completely resolved in 22.2%, and 33.3% experienced no change. Ninety-one percent of SH patients completely resolved, 6% improved, but 3% worsened, with one patient developed hypothyroidism. Both groups achieved a significant decrease in postoperative BMI. A positively statistically significant association was found between BMI and TSH (p < 0.005). Conclusions Our results favor the effect of laparoscopic sleeve gastrectomy in the obese population with overt and SH as shown by the majority of SH resolution and overt hypothyroidism improvement.