Impact of body mass index on post-thyroidectomy morbidity.

Background The impact of obesity on total thyroidectomy (TT) morbidity (recurrent laryngeal nerve palsy and hypocalcaemia) remains largely unknown. Methods In a prospective study (NCT01551914), patients were divided into five groups according to their body mass index (BMI): underweight, normal weight, overweight, obese, and severely obese. Preoperative and postoperative serum calcium was measured. Recurrent laryngeal nerve (RLN) function was evaluated before discharge, and if abnormal, at 6 months. Results In total 1310 patients were included. Baseline characteristics were similar across BMI groups except for age and sex. Postoperative hypocalcaemia was more frequent in underweight compared to obese patients but the difference was not statistically significant in multivariate analysis. There was no difference between groups in terms of definitive hypocalcaemia, transient and definitive RLN palsy, and postoperative pain. Conclusion Obesity does not increase intraoperative and postoperative morbidity of TT, despite a longer duration of the procedure.