Hypocalcemia after thyroidectomy in patients with a history of bariatric surgery

Hypocalcemia is a common complication after total thyroidectomy. Previous bariatric surgery could be a higher factor risk for hypocalcemia due to alterations in calcium absorption and vitamin D deficiency.

To evaluate incidence and factors involved in the risk of hypocalcemia (transient and permanent) and the postoperative outcomes of these patients after total thyroidectomy.

University hospital in Paris, France.

All patients who had previously undergone obesity surgery (i.e., Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric band) who had a total thyroidectomy from 2006 to 2015 were included. No patient was lost to follow-up. Each patient was matched 1:1 with a patient who had no previous bariatric surgery for age, gender, body mass index, and year of surgery.

Forty-eight patients were identified (43 female; mean age 48.9±9.2 yr). Nineteen patients (40%) had a postoperative hypocalcemia: transient in 14 patients (29.2%) and permanent in 5 patients (10.4%). No significant predictive clinical or biochemical factors were found for hypocalcemia risk, except for the type of bariatric procedure: Bypass surgery had a 2-fold increased risk of hypocalcemia compared to others procedures (60% versus 30%, P = .05). In the matched pair analysis, the risk of hypocalcemia was significantly higher in patients with previous bariatric surgery than in the matched cohort (40% versus 15%, P = .006).

Patients with previous bariatric surgery have an increased risk for hypocalcemia after total thyroidectomy, especially after Roux-en-Y gastric bypass. Careful and prolonged follow-up of calcium, vitamin D, and parathyroid hormone levels should be suggested for these patients.