THYROID FUNCTION BEFORE AND AFTER ROUX-EN-Y GASTRIC BYPASS OBSERVATIONAL STUDY

Abstract Background Population studies have shown a positive association between TSH and BMI. Recent studies have shown a significant increase in the prevalence of subclinical hypothyroidism (SCH) in obesity. Weight reduction after Roux-en-Y gastric bypass (RYGB) seems to significantly decrease TSH levels Objectives The purpose of this study was to evaluate the prevalence of SCH in obese patients (class II and III) and to observe the behavior of thyroid hormones (TSH, T3, T4, FT4) with significant weight loss after RYGB Setting Hospital Nossa Senhora das Gracas, Curitiba, Parana, Brazil Methods We retrospectively reviewed the medical records of 215 obese patients who underwent RYGB between 2005 and 2012 with a follow-up of at least 2 years. The study was observational and descriptive. The selected times for clinical and laboratory evaluations were: preoperative, 3, 6, 12, and 24 months after the procedure. Association, correlation and variance analyses were performed Results The prevalence of SCH preoperatively was 9.3%. SCH was corrected in 89.5% of patients 12 months after RYGB. We did not find an association between TSH and BMI (r = 0.002, p = 0.971). There was a positive impact of bariatric surgery on all metabolic variables. We showed that serum TSH level had no positive correlation with the presence or absence of metabolic syndrome Conclusions Weight loss after bariatric surgery leads to normalization of TSH levels in most patients and none developed overt hypothyroidism. Obese patients with SCH should not be treated with thyroid hormone replacement. Serial monitoring of thyroid function after obesity therapy seems to be a reasonable approach.