Dutch Study Finds High Rate of Hypoparathyroidism After Thyroid Surgery
A new study out of the Netherlands has found a high incidence — 15% — of long-term hypoparathyroidism in patients after surgery on the thyroid gland.
“These data provide a better understanding of the magnitude of this postoperative complication and enable more realistic information for patients who are undergoing extensive and complex thyroid surgery,” its researchers wrote.
“Efforts should be made to reduce this complication rate and use national uniform treatment guidelines to enable comparison of interventions,” they added.
The study, “Persistent Postthyroidectomy Hypoparathyroidism in the Netherlands,” was published in JAMA Otolaryngology – Head & Neck Surgery.
Hypoparathyroidism is a rare disease characterized by low levels of parathyroid hormone (PTH). This hormone is made by the parathyroid glands, four small structures that sit beside the thyroid gland in the throat.
During thyroidectomy — a surgery to remove all or part of the thyroid gland — the parathyroid glands can be damaged, which may lead to hypoparathyroidism. However, it is not clear how common this post-surgical complication is. Estimates vary markedly across studies, and many published studies use only data from a single center, limiting generalizability.
Now, researchers reported the rate of hypoparathyroidism among 200 patients who underwent thyroid surgery at one of seven university hospitals in the Netherlands in 2016. Among these patients, the median age was 49 years, about three-quarters were female, and the most common reason for undergoing thyroid surgery was cancer in the thyroid.
Of the 200 patients, 30 (15%) developed persistent hypoparathyroidism, which was defined as the need for vitamin D with or without calcium supplementation for at least one year after surgery.
Among the seven different hospitals included in the study, rates of persistent post-surgery hypoparathyroidism ranged from 5.6% to 26.9%. “No meaningful difference” in rates was found among the seven institutions, the researchers wrote.
The team noted that there is no single agreed-upon definition for what constitutes “persistent hypoparathyroidism.” Different studies have used different definitions, including varying requirements about nutritional supplements, as well as different lengths of time deemed “long-term.”
Among these 200 patients, the incidence of persistent hypoparathyroidism ranged from 14.5% to 28.5% with different definitions used.
“Despite persistent hypoPT [hypoparathyroidism] being such a common complication, we lacked uniformity in definition and treatment,” the researchers wrote.
“An international consensus for the definition of persistent hypoPT after thyroid surgery and the development of reliable registration systems can serve national and international benchmarking purposes that aim for improved quality for patients who are treated with total or completion thyroidectomy,” they added. “Furthermore, new techniques that aim to decrease hypoPT after thyroid surgery should be investigated and implemented.”