Michael Zhou, BA, Jordan Grubbs, MD, David Berler, MD, Benjamin E Schneider, MD, Sara A Hennessy, MD. University of Texas Southwestern Medical Center
Introduction: Thyroid dysfunction and obesity are intricately connected with a positive correlation between BMI and TSH. Bariatric surgery is one of the most effective long-term treatments of obesity and its co-morbidities. Likewise, changes in thyroid function, correlating decrease of medication dosage, and even resolution of hypothyroidism have been reported in post-operative patients. However, the literature is sparse on the long-term effects of bariatric surgery on hypothyroidism. In this study, we aimed to review the effects of bariatric surgery on hypothyroidism over 2 years.
Methods and Procedures: A retrospective review was conducted of patients undergoing sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RNYGB) procedures at a university-affiliated academic institution from 2014 to 2016. Patients with hypothyroidism were evaluated for changes in thyroid stimulating hormone (TSH) and dose of hypothyroid medication over follow up periods of 6, 12, and 24 months were evaluated. Patients were compared by comorbidities, type of surgery, BMI change and outcomes.
Results: Of the 401 bariatric surgery patients, 63 patients had preoperative diagnosis of hypothyroidism. Of the patients with hypothyroidism, 24 patients had adequate TSH follow up. Preoperative mean TSH was 2.15 with a BMI of 43.6. At 24 months there was a decrease to a TSH of 1.33 and a BMI of 33.2 (Table1). Of these patients, 4 (16.7%) had a dose decrease in their thyroid replacement medication postoperatively with an average of reduction in dose by 31.2%.
When comparing SG and RNYGB in hypothyroid patients, there was a significant difference in BMI change of 7.97 and 13.5, respectively (p=0.03), and TSH decreased by 0.21 and 0.64, respectively (p=0.04).
Table 1. TSH and BMI changes over follow up periods.*: Statistical significant decrease in BMI occurred post-operatively (p < 0.01). There was no statistically significant decline in TSH and no correlation between BMI and TSH changes.
Conclusion: Bariatric patients with well-controlled preoperative hypothyroidism are safe to undergo either sleeve gastrectomy or Roux-en-Y gastric bypass surgery. They can continue to achieve adequate control of their hypothyroidism without a negative impact on absorption of hypothyroid medications. There is a trend towards improvement in hypothyroidism with decreases in thyroid medication doses. Roux-en-Y gastric bypass is potentially superior to gastric sleeves in treatment of hypothyroidism, with significant improvement in thyroid function. A prospective study is necessary to understand the true impact of bariatric surgery on hypothyroidism.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 94189
Program Number: P097
Presentation Session: Poster Session (Non CME)
Presentation Type: Poster
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