Postoperative hypothyroidism and body weight dynamics in patients operated on for diffuse toxic goiter

Abstract

Postoperative hypothyroidism is a consequence of thyroidectomy. However, observation of patients with diffuse toxic goiter (DTG) after thyroidectomy shows that achieving euthyroidism while taking L-thyroxine, as well as maintaining weight in some cases, is difficult or not possible at all. Thus, the study of thyroid function and body weight dynamics in the first year after thyroidectomy remains an urgent task of clinical thyroidology.Aim. To study thyroid function and body weight dynamics in patients with DTG after various types of surgical treatment.Material and methods. The study included 310 patients with DTG (234 women — 75,5% and 76 men — 24,5%), the average age was 46,46±0,99 years. In all patients with DTG before surgery, after 1 month and 1 year after the operation, the results of hormonal examination (levels of thyroid-stimulating hormone (TSH), free T4), body weight dynamics were evaluated. Levels of TSH and free T4 was determined by enzyme immunoassay. To assess the dynamics of body weight one year after the operation, depending on the change in weight, the patients were divided into 3 groups: group 1 — body weight decreased by more than 5%; group 2 — body weight did not change; group 3 — body weight increased by more than 5%. Statistical analysis of the study results was performed using the SPSS 16.0 program (SPSS Inc., USA).Results. Before surgical treatment, blood TSH levels were normal in all patients, and there were no differences between the groups (p=0,94). In patients after subtotal resection, the average level of TSH in the blood after 1 month. after surgery was significantly higher (p=0,02) than in patients who underwent extirpation of the thyroid gland (TG). Blood TSH was monitored in all patients 1 year after surgery. In patients with thyroid extirpation, the level of TSH in the blood was significantly higher compared to patients who underwent organ-preserving surgery (p=0,01).Next, the body mass index (BMI) was analyzed in the examined groups of patients. When analyzing the BMI of patients before and after surgery, there were no significant differences in both groups: group 1 — before surgery BMI 25,67±0,57 kg/m2, after surgery 25,87±0,60 kg/m2; group 2 — before surgery BMI 25,13±0,40 kg/m2, after surgery 25,67±0,46 kg/m2. In group 1, there was a decrease in weight after surgery during the first year in 14,9% of patients, while in group 2 only in 7,2% of patients (p=0,01). Weight gain was high in both groups: in group 1 — 20,7%, in group 2 — 29,0%, but in the group after thyroidectomy was significantly higher (p=0,04). In patients with weight gain, a positive correlation was found between weight gain during the year and blood TSH 1 year after surgery (p=0,02, r=0,247).Conclusion. The obtained results suggest that after thyroidectomy performed for DTG, patients have a significantly greater increase in BMI and uncompensated hypothyroidism is more common than in patients after subtotal resection of the thyroid gland.