Postoperative symptomatic hypocalcemia linked to preoperative vitamin D deficiency in thyroid cancer

CORONADO, Calif. — Patients with thyroid cancer who also have preoperative vitamin D deficiency are at increased risk of postoperative symptomatic hypocalcemia, according to study findings presented here.

Kee-Hyun Nam, MD, PhD, and colleagues from the department of surgery at Yonsei University College of Medicine, evaluated 267 thyroid cancer patients who underwent total thyroidectomy with central compartment neck dissection to determine if preoperative vitamin D deficiency is associated with postoperative symptomatic hypocalcemia.

Patients were divided into two groups based on preoperative vitamin D levels: vitamin D deficiency (<10 ng/ml; group 1) and no vitamin D deficiency (≥10 ng/ml; group 2). Symptomatic hypocalcemia was defined as the presence of any signs or symptoms of hypocalcemia and serum calcium <8.2 mg/dL.

Group 2 had lower rates of postoperative symptomatic hypocalcemia (30.4%) compared with group 1 (43.8%; P=.043). A preoperative vitamin D level of <10 ng/ml was predictive of postoperative symptomatic hypocalcemia.

When postoperative intact parathyroid hormone levels were <15 pg/ml, group 1 had higher rates of symptomatic hypocalcemia (77.5%) compared with group 2 (53.2%; P=.008).

Compared with vitamin D deficiency, the risk of symptomatic hypocalcemia was reduced by 72% when preoperative levels vitamin D levels were >20 ng/ml (P=.003).

“[Vitamin D deficiency] is significantly associated with postoperative symptomatic hypocalcemia in thyroid cancer patients undergoing [total thyroidectomy] plus (central compartment neck dissection],” the researchers wrote. “[Vitamin D deficiency could predict symptomatic hypocalcemia in cases of postoperative serum [intact PTH] levels <15 pg/nl.”

For more information:

Kim W. Oral #14. Presented at: American Thyroid Association Annual Meeting; Oct. 29-Nov. 2, 2014; Coronado, Calif.

Disclosure: The researchers report no relevant financial disclosures.