Weight change in patients with differentiated thyroid carcinoma after total thyroidectomy versus lobectomy

Thyroid hormone is an important hormone in maintaining metabolism and homeostasis in the body. There exists a common perception among patients that thyroid surgery will cause weight gain. Prevention of any undesired weight gain could be important for the maintenance of well-being in most patients. Our study compares changes in body mass index (BMI) and weight after total thyroidectomy or lobectomy in thyroid cancer patients.

A total of 967 patients with differentiated thyroid carcinoma were enrolled in the study, from March 2011 to July 2016 at Chung-Ang University Hospital. Exclusion criteria were less than lobectomy, modified radical neck dissection, recurred operation, and combined operation for other causes. Primary endpoints were change in body weight and BMI at 2 years after surgery. A subgroup analysis was performed for patients with significant weight change.

There were no differences between both groups in BMI after 2 years of thyroid operation. Thyroid stimulating hormone (TSH) levels were not significantly different. Fifteen percent of patients showed significant change in body weight after 2 years of operation. The subgroup analysis of these patients showed no significant differences in gender, age, or extent of operation between those who had gained weight compared to those who had lost weight. There were also no differences in postoperative TSH levels, levothyroxine supplementation, or radioactive iodine treatment.

There was a minimal postoperative increase in mean BMI over the years in patients undergoing thyroidectomy for differentiated thyroid cancer. However, weight change did not differ in those undergoing thyroid lobectomy or total thyroidectomy.