Hypoparathyroidism in children often temporary after surgery
Study included data from 121 children who had thyroid removed due to cancer
Hypoparathyroidism is often temporary in children who undergo surgical removal of the thyroid, or thyroidectomy, with most recovering normal parathyroid function within six months, a study in China shows.
The time needed to recover from hypoparathyroidism was found to be closely related to the levels of parathyroid hormone (PTH) on the day after surgery. Children included in the study underwent thyroidectomy due to thyroid cancer.
“Children with thyroid cancer are in the period of growth and development, with a long survival time, and the influence of [hypoparathyroidism] is more serious and long-term,” which should be widely concerning, according to researchers.
The study, “Influencing Factors of Hypoparathyroidism After Thyroidectomy in Children,” was published in the Ear, Nose & Throat Journal.
Hypoparathyroidism is characterized by low levels of PTH, a key regulator of blood levels of calcium and phosphorus. Low PTH levels result in low calcium and high phosphorus, which can cause a wide range of symptoms.
Damage to parathyroid glands can happen during thyroidectomy
The disease is often caused by accidental damage to the parathyroid glands, four small glands in the neck that produce PTH, during surgery to remove the thyroid gland. This procedure is typically the first treatment choice for children with thyroid cancer.
In such cases, hypoparathyroidism is commonly temporary, and the levels of PTH gradually normalize. However, “there is no report on the recovery of [hypoparathyroidism] after total thyroidectomy in children,” the researchers wrote.
To know more, researchers at Beijing Children’s Hospital retrospectively analyzed data from 121 children who underwent total thyroidectomy due to thyroid cancer at their hospital, from June 2016 to December 2020. Children were an average age of 10.3 years, ranging from 3 to 15 years. Most were girls (64.7%).
Overall, 34 children (28.1%) developed hypoparathyroidism after surgery, which also removed lymph nodes in one (5.9%) or both sides (94.1%) of the neck due to cancer spreading.
“Due to the wide range of invasion and high rate of lymph node metastasis in pediatric thyroid cancer, it is difficult to identify the parathyroid glands, and more meticulous protection is needed,” the researchers wrote.
PTH levels returned to normal within one month in more than half of the patients (52.9%). Within six months, 25 children (73.5%) had normal PTH levels, and nearly all (88.2%) achieved normal levels within one year. Two patients recovered normal PTH levels after more than one year post-surgery.
2 children with long-term low PTH levels had cancer metastases
In the two remaining cases, PTH levels had still not returned to normal at the last follow-up, which in one case was five years. Both had extensive cancer spreading outside the thyroid and multiple metastases into the lymph nodes. Also, their PTH level was lower than 1 picogram/mL (pg/mL) on the first day following surgery.
Statistical analysis indicated PTH levels of 1 pg/mL or lower on the day after surgery significantly impacted the recovery of PTH levels.
Previous studies had indicated that determining PTH levels shortly after surgery may help predict patients who are at risk of hypoparathyroidism. “PTH assay is a reliable early predictor, as it may allow earlier identification of patients requiring treatment for postthyroidectomy hypocalcemia [low calcium levels] and should be routinely monitored after thyroid surgery,” the scientists wrote.
Overall, the study suggested “it is necessary to be cautious about the diagnosis of permanent [hypoparathyroidism] in children because [it] may recover after 1 year,” the researchers noted. “The diagnosis of permanent [hypoparathyroidism] implies lifelong medical care, increases the economic burden, and affects the quality of life of the child.”
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