Increased Body Mass Index is Associated With Lower Risk of Hypocalcemia in Total Thyroidectomy Patients.

INTRODUCTION: Hypocalcemia following total thyroidectomy is common due to postoperative parathyroid dysfunction. We sought to identify the impact of obesity on postthyroidectomy hypocalcemia. METHODS: We performed a single-center retrospective study of all total thyroidectomies performed from 2016 to 2019 after implementation of an updated calcium supplementation protocol. Patient characteristics and outcomes were measured including body mass index (BMI), postoperative hypocalcemia (Ca <8.3), and hypocalcemic symptoms. RESULTS: Overall, 559 total thyroidectomies were performed. A total of 146 patients (26.2%) developed hypocalcemia requiring supplementation adjustment and 116 patients (20.8%) developed mild hypocalcemia symptoms. On multivariable analysis, younger patients, patients with lower preoperative calcium, and lower BMI were more likely to develop postoperative hypocalcemia (all P < 0.05). Similarly, younger patients and patients with BMI <25 were more likely to develop hypocalcemic symptoms (all P < 0.05). CONCLUSIONS: Younger age and lower BMI were associated with increased risk of hypocalcemia after total thyroidectomy. These patients may benefit from preoperative and/or increased postoperative supplementation.