Bariatric surgery may induce weight loss and improve Thyroid Functions: Study

In a groundbreaking study, researchers have uncovered the intricate relationship between bariatric surgery, thyroid function, and postoperative weight loss. This study, conducted on euthyroid patients with obesity offers unprecedented insights into the dynamics of this relationship. The study results were published in the journal Frontiers in Endocrinology.

Bariatric surgery, renowned for its effectiveness in weight reduction, has long been associated with potential alterations in thyroid-stimulating hormone (TSH) and thyroid hormones. Hence researchers conducted a study to understand the relationship between thyroid function and bariatric surgery on euthyroid obese patients who underwent sleeve gastrectomy and Roux-en-Y gastric bypass between 2017 and 2022. The primary focus of the investigation was the assessment of alterations in key thyroid hormones, namely free thyroxine (FT4), free triiodothyronine (FT3), total thyroxine (TT4), total triiodothyronine (TT3), and thyroid-stimulating hormone (TSH). These assessments were conducted one-year post-surgery to discern any notable changes in thyroid function resulting from the weight loss interventions.

Findings:

• The research, involving 256 patients, revealed a remarkable mean total weight loss (%TWL) of 28.29% one year after surgery.
• Strikingly, postoperative analyses demonstrated significant decreases in TSH, free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3), and total thyroxine (TT4). Interestingly, the study categorized %TWL into three groups for a more nuanced analysis—%TWL ≤ 25%, 25% < %TWL ≤ 35%, and %TWL > 35%.
• Pearson correlation analysis established a substantial association between the percentage of total weight loss and the change in TSH (ΔTSH), revealing that as weight loss increased, TSH levels decreased.
• Further validating this connection, multivariable linear regression demonstrated that %TWL was independently linked to ΔTSH.
• The results remained consistent, confirming that %TWL independently predicted ΔTSH even after accounting for various covariates.

In conclusion, this study sheds light on the transformative effects of bariatric surgery, not only as a powerful weight-loss tool but also as a modulator of thyroid function. The observed declines in TSH, FT4, FT3, TT4, and TT3 signify a complex interplay, with weight loss emerging as a key determinant. These findings not only contribute to our understanding of the post-bariatric surgery landscape but also pave the way for personalized approaches to weight loss with considerations for thyroid function. The implications of this research stretch beyond the realm of obesity management, offering hope for those navigating the intricate relationship between weight loss, thyroid health, and surgical interventions.

Further reading: Total weight loss induces the alteration in thyroid function after bariatric surgery. Doi:  https://doi.org/10.3389/fendo.2024.1333033