Magnesemia: an independent risk factor of hypocalcemia after thyroidectomy

Wenlong Wang*, Chaoyang Meng*, Qianhui Ouyang, Jing Xie, Xinying Li Division of Thyroid, General Surgery Department, Xiangya Hospital, Central South University, Changsha 410008, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xinying LiDivision of Thyroid, General Surgery Department, Xiangya Hospital, Central South University, No.87 Xiangya Road, Changsha 410008, People’s Republic of ChinaTel +86 07 318 975 3710Email lixinyingcn@126.comBackground: This study was designed to investigate the impact of serum magnesium (Mg) levels on hypocalcemia after thyroidectomy.Patients and methods: In total, 242 patients with differentiated thyroid cancer were retrospectively analyzed.Results: Multivariate regression analysis showed hypomagnesemia was an independent risk factor for hypocalcemia (P0.05). In patients with normal Po-Ca levels, hypomagnesemia increased the risk of symptoms related to hypocalcemia by 4.478 times (OR =5.478, 95% CI 1.724–17.403).Conclusion: Hypomagnesemia, or even a low serum Mg level within the normal range, can increase the risk of hypocalcemia. After excluding the potential effects of PTH on serum magnesium and calcium, serum Mg reduction is one of the most important factors that influences postoperative serum Ca reduction. What’s more, hypomagnesemia is closely linked with symptoms.Keywords: hypocalcemia, hypomagnesemia, thyroidectomy, magnesium, calcium