Weight Gain After Thyroidectomy: A Systematic Review and Meta-Analysis

Abstract

Context: Weight gain is a major driver of dissatisfaction and decreased quality of life in patients with hypothyroidism. Data on the changes in body weight following thyroidectomy are conflicting.

Objective: To perform a systematic review of the literature and a meta-analysis of weight changes following total thyroidectomy.

Data sources: Literature search on PubMed.

Study selection: Studies in English published between September 1998 and May 2018 reporting post-thyroidectomy weight changes.

Data extraction: Data were reviewed and compared by 3 investigators; discrepancies were resolved by consensus. Meta-analyses were performed using fixed and random effect models. Univariable and multivariable meta-regression models for weight change were implemented against study follow-up, gender, and age. Exploratory subgroup analyses were performed for indication for surgery.

Data synthesis: Seventeen studies (3164 patients) with 23.8 ± 23.6 months follow-up were included. Severe heterogeneity across studies was observed. Using a random effect model, the estimated overall weight change was a gain of 2.13 kg, 95% confidence interval (CI; 0.95, 3.30). Age was negatively associated with weight change (β = -0.238, P < 0.001). In subgroup analyses, weight gain was more evident in patients undergoing thyroidectomy for hyperthyroidism: 5.19 kg, 95% CI (3.21, 7.17) vs goiter or malignancy 1.55 kg, 95% CI (0.82, 2.27) and 1.30 kg, 95% CI (0.45, 2.15), respectively.

Conclusions: Patients undergoing thyroidectomy experience possible mild weight gain, particularly younger individuals and those with hyperthyroidism as the indication for surgery. Prospective studies directed to assess the pathophysiology of weight gain post-thyroidectomy, and to test novel treatment modalities, are needed to better characterize post-thyroidectomy weight changes.

Keywords: hypothyroidism; levothyroxine; meta-analysis; systematic review; thyroidectomy; weight gain.