Endocrine Abstracts

Objective: Euthyroid patients undergoing thyroidectomy were reported to gain weight than their matched counterparts. The etiology is still unknown. Serum adiponectin and leptin levels are related to fat mass and thyroid hormones. We aimed to evaluate the influence of thyroidectomy on body composition, serum adiponectin, leptin levels in euthyroid obese and non-obese patients who underwent total thyroidectomy for goiter.

Methods: We conducted a prospective observational study in a training hospital. Twenty-one euthyroid normal-weight patients (16F/5 M, mean age 43.5±8.4 y), 19 obese patients (17F/2 M, mean age 44.3±8.7 y) and 22 healthy controls (21F/1 M mean age 40.4±10.2) were included in the study. Main anthropometric measures, body fat distribution by bioelectrical impedance analysis, preperitoneal fat thickness, plasma glucose (FPG), insulin, lipids, thyroid hormones, leptin, and adiponectin levels were evaluated before and after surgery. L-thyroxine treatment was started immediately. All patients were maintained in a euthyroid status throughout the study, and patients were re-evaluated three months after the achievement of euthyroidism.

Results: At baseline, obese patients had significantly higher BMI, waist circumference (WC), total fat mass, lean body mass, and SC fat thickness than normal-weight subjects and healthy controls (P<0.001 for all). Obese patients had higher visceral fat mass than normal-weight patients at a Plevel of 0.051 (11.0±4.5% vs. 8.4±3.9%). Serum fasting insulin and leptin levels and HOMA-IR values were significantly higher in obese patients (P<0.05 for all). In contrast, all groups had comparable FPG and adiponectin levels (P>0.05 for both). Mean TSH and free T4 levels were also similar. Although BMI and WC remain unchanged (P>0.05), the visceral fat mass increased significantly after surgery (8.4±3.9 vs. 10.0±4.1 in normal-weight; 11.0±4.5 vs. 15.5±6.0 in obese; P<0.05). Despite a significant increase in TSH levels, the values remained normal in both groups. Both groups did not show any significant change in serum FPG, insulin, leptin, and adiponectin levels (P>0.05 for all).

Conclusions: Total thyroidectomy caused increased visceral fat mass despite no change in clinical anthropometric measures in patients who had a thyroidectomy due to goitre. This change was unrelated to serum adiponectin and leptin levels.