Study on Hypocalcemia Risk After Thyroidectomy

A significantly greater risk of hypocalcemia after thyroidectomy is observed in patients with a history of bariatric surgery. Patients who have had a bypass procedure had a further heightened risk. These are the results of a new study published in the British Journal of Surgery.

"Surgeons carrying out thyroid surgery should be informed of the increased hypocalcemia risk following thyroidectomy in these patients," Eoin F Cleere, Lambe Institute for Translational Research, National University of Ireland Galway, Galway, Ireland, and colleagues wrote in their study.

After surgical removal of the thyroid gland, hypocalcemia (low calcium levels) is a complication. Weight loss surgery is tied to significant changes in calcium metabolism and is prone to hypocalcemia. Some researchers have identified bariatric surgery as a risk factor for hypocalcemia following thyroidectomy. The article assessed whether a history of bariatric surgery was tied to an increased hypocalcemia risk after thyroidectomy through systematic review and meta-analysis.

The researchers performed a prospectively registered systematic review per PRISMA guidelines. The Mantel–Haenszel method was used to conduct a meta-analysis. The outcomes were reported as ORs.

Twenty studies were involved in the qualitative synthesis. Five studies consisting of 19,547 patients met the inclusion criteria for meta-analysis; out of this, 196 (1.0 percent) had a history of bariatric surgery.

Findings

• Patients with prior bariatric surgery were at higher risk of developing hypocalcemia after thyroidectomy (30.6 versus 13.0 percent; OR 3.90).
• Among those with a history of bariatric surgery, patients who underwent a bypass procedure were more likely to develop hypocalcemia after thyroidectomy than those with a restrictive procedure (38 versus 23 percent; OR 2.12).

In simpler words, previous weight loss surgery in patients was tied to three times increased risk of low calcium levels after thyroid surgery. "Low-calcium management in these patients is more challenging than in patients who have not had weight loss surgery," the authors wrote.

"Surgeons performing thyroid surgery need to be cognizant of whether a patient has previously had weight loss surgery as they have an increased risk of low calcium after thyroidectomy," they concluded.

Reference

Eoin F Cleere, Matthew G Davey, Thomas J Crotty, Orla Young, Aoife J Lowery, Michael J Kerin, Hypocalcaemia following thyroidectomy among patients who have previously undergone bariatric surgery: systematic review and meta-analysis, British Journal of Surgery, 2022;, znac310, https://doi.org/10.1093/bjs/znac310