Total Thyroidectomy and Subsequent Weight Gain in Pediatric Populations

Objective: To evaluate weight gain in children post-thyroidectomy and identify predictors. Methods: Charts from patients at a tertiary health care facility who underwent total thyroidectomy from 2014 to 2020 were reviewed for Body Mass Index z-scores (BMIz) at the time of thyroidectomy and at 1 and 2-year post-operation intervals. Patient demographic information, comorbidities, pre- and postoperative thyroid stimulating hormone, and postoperative free T4 levels were also extracted. Patients with other known endocrine abnormalities, chronic kidney disease, or without sufficient follow-up were excluded. Results: A total of 56 patients (ages 3-17 years old) met the inclusion criteria (n = 17 Graves' disease; n = 39 presumed cancer). Over the first year, average BMIz significantly increased in patients with Graves' disease ( increment BMIz = 0.45 +/- 0.77, p = 0.03), Hispanic ethnicity ( increment BMIz = 0.43 +/- 0.68, p = 0.004), Medicaid/no insurance coverage ( increment BMIz = 0.33 +/- 0.74, p = 0.038), age < 13 years at thyroidectomy ( increment BMIz = 0.35 +/- 0.68, p = 0.016), and persistent postoperative hypothyroidism ( increment BMIz = 0.41 +/- 0.41, p = 0.012). These changes remained significant after the second year. Age at thyroidectomy correlated negatively with increment BMIz only after the first year (r = -0.40, p = 0.002). Regression analysis, controlling for Graves' status, persistent postoperative hypothyroidism, and insurance coverage, identified age at thyroidectomy as a significant predictor of increment BMIz after the first year (b = -0.06, p = 0.004) and Hispanic ethnicity as a significant predictor after the second year (b = 0.60, p = 0.003). Conclusion: A small increase in BMIz post-thyroidectomy was observed across several patient subgroups. Younger age at thyroidectomy and Hispanic ethnicity were associated with increased BMIz in the first 2 years post-thyroidectomy.