Why Weight Gain After Thyroid Surgery?

A new study has revealed that it is not thyroid hormones that are responsible for weight gain after thyroid surgery, but the lack of 'calcitonin' hormone in the thyroid gland. Endocrine Surgery Specialist Prof. Dr. Erhan Ayşan emphasized that in the light of these findings, surgical techniques should be re-evaluated and healthy parts of the thyroid gland should be preserved as much as possible.  Prof. Dr. Ayşan said, “The thyroid gland is the orchestra conductor of the body. We now know that this conductor has another task: Releasing calcitonin. Recent findings have once again shown that we need to be much more meticulous in thyroid surgeries.”.
Weight gain is one of the most common complaints of patients undergoing thyroid surgery. Yeditepe University, Kosuyolu Hospital Endocrine Surgery Specialist shared the findings of his new research on the subject, published in Endocrinology and Metabolism, an internationally respected journal. Stating that this situation has been generally attributed to the lack of thyroid hormones until today, but this view does not reflect the truth, our specialist said, “Patients often think ‘I had my thyroid removed, my hormones were deficient and that is why I gained weight’. However, recent studies show that the cause of weight gain is not thyroid hormones, but calcitonin hormone deficiency secreted from the thyroid gland.”.

What are the Functions of Calcitonin Hormone?

Our Endocrine Surgery Specialist said about the hormone calcitonin, “For many years, calcitonin was only known as a hormone related to bone health. However, new research has revealed that this hormone plays an important role in providing a feeling of satiety, slowing stomach emptying and increasing insulin sensitivity. Calcitonin is actually critical not only for bones but also for metabolism. In surgeries where the entire thyroid is removed, we lose not only thyroid hormones but also calcitonin. This leads to weight gain.”.

Thyroid Surgery May Preserve Calcitonin-Secreting Cells

Our specialist drew attention to the importance of surgical methods that protect healthy thyroid tissue in thyroid surgeries and gave the following information about protection: “In thyroid surgeries, it would be a more accurate approach to remove only the diseased part of the thyroid gland, not the entire thyroid gland. In this way, the cells that secrete the hormone calcitonin can be preserved and the risk of postoperative weight gain can be reduced.” Stating that calcitonin hormone is secreted from a different organ called 'ultimobrankial organ' outside the thyroid gland in all mammals other than humans, our specialist said, “This organ is not only present in humans and interestingly, the cells that make up this organ are spread in the thyroid gland in humans. In other words, the thyroid gland actually consists of two organs, not one. When we remove the entire thyroid gland with surgery, we also remove this organ. However, when part of the thyroid gland is left, a sufficient amount of calcitonin may remain in the body and this may prevent weight gain.”

Is There Treatment for Calcitonin Hormone Deficiency?

Emphasizing that it is not currently possible to take calcitonin hormone as an external drug, our expert said, “In the past, calcitonin drugs were available, but their sale was banned due to side effects. Therefore, taking calcitonin externally, such as thyroid hormones, is currently not an option. Therefore, the most effective way to maintain the metabolic balance of patients after surgery is to leave healthy thyroid tissue in place as much as possible.”.

Whole Thyroid Can Be Removed in Case of Cancer

Stating that it may be mandatory to remove the entire thyroid gland in cases of thyroid cancer or in the presence of severe and large nodules, our specialist emphasized that the priority of patients in these cases should be to treat cancer. Our Endocrine Surgeon said: “In the case of a serious condition such as cancer, it may be vital to remove the entire thyroid gland. However, in small tumors and less risky cases, removing only the diseased part and preserving the healthy tissue will be more advantageous for the patient's general health and weight control.

One of the Functions of the Thyroid Gland is to Secrete Calcitonin

Finally, our expert stated that the thyroid gland is already defined as an 'orchestra conductor' in the body and with new findings, the duties of this orchestra conductor have become even more important, “Physicians always say that ‘the thyroid gland is the orchestra conductor of the body’. The thyroid manages the body with its hormones. But now we see that this conductor has another task: To secrete calcitonin. Now, with these data, we have increased the value of the thyroid gland one more time. Therefore, we have learned once again that we need to be much more meticulous and protective in thyroid surgeries. Modern surgical approach will both protect the health and improve the quality of life of our patients.”.