Hypoparathyroidism After Thyroid Surgery Can Greatly Affect Life Quality

People who develop chronic hypoparathyroidism following surgery to remove the thyroid gland have significantly poorer quality of life than those whose surgery does not permanently damage the neighboring parathyroid glands, a Danish study shows.

Notably, hypoparathyroidism’s negative affect on life was independent of the drop in thyroid-related hormones (hypothyroidism) due to gland removal, patients’ other health conditions, and their calcium levels.

The study, “Postoperative Chronic Hypoparathyroidism and Quality of Life after Total Thyroidectomy,” was published in the journal JBMR Plus/Journal of Bone and Mineral Research Plus.

Surgery to completely remove the thyroid gland, called total thyroidectomy, can lead to the unintentional removal of the neighboring parathyroid glands and to chronic hypoparathyroidism, or low levels of the parathyroid hormone (PTH).

Given that PTH regulates calcium levels in the body, low or no levels of PTH may cause post-surgery calcium deficiency (hypocalcemia).

Hypoparathyroidism may lead to muscle cramps, tingling in the extremities, fatigue, anxiety, headaches, dry skin, and cognitive and psychologic problems — all of which can affect life quality.

People with chronic hypoparathyroidism due to total thyroidectomy also show concurrent hypothyroidism, which was previously shown to independently impact quality of life. However, it is “unclear whether QoL [quality-of-life] impairment in chronic HypoPT [hypoparathyroidism] is due to insufficient production of PTH, thyroid hormones, or a combination,” the researchers wrote.

In an attempt to clarify this, scientists in Denmark evaluated whether quality of life is lower in people with chronic hypoparathyroidism associated with thyroidectomy, independently of simultaneous hypothyroidism.

They analyzed demographic information, clinical and lab data, and quality of life for 14 women who developed chronic hypoparathyroidism (lasting at least six months) after total thyroidectomy, and 28 age-matched women who had intact parathyroid function after surgery.

All these patients had their thyroid removed between 2013 and 2018 at Zealand University Hospital. None of the surgeries were associated with a diagnosis of thyroid cancer.

Quality of life was assessed with the validated, self-reported 36‐Item Short Form Health Survey (SF‐36), which comprises eight domains of physical and mental health: physical functioning, bodily pain, role limitations due to physical problems, energy/fatigue, social functioning, role limitations due to emotional problems, mental health, and general health.

Results showed that women with chronic hypoparathyroidism had lower quality of life scores in all domains of the SF-36, compared with those with unaffected parathyroid function following surgery.

Notably, chronic hypoparathyroidism was associated with significantly lower scores in six of the eight quality-of-life domains even after adjusting for potential influencing factors, including age, simultaneous conditions, and levels of calcium and the thyroid hormone TSH (evaluated to assess hypothyroidism).

Affected domains included physical functioning, bodily pain, role limitations due to physical problems, energy/fatigue, mental health, and general health. They represent clinically important changes in the SF-36 scores, the team said.

These findings suggest that chronic hypoparathyroidism associated with thyroidectomy is linked to significantly poorer quality of life, regardless of hypothyroidism, co-existing conditions, and calcium and TSH levels.

Women with chronic hypoparathyroidism also showed significantly lower scores in the physical problems-related role limitations, energy/fatigue, and general health domains after adjusting for surgical indication.

These associations between chronic hypoparathyroidism and poorer quality of life were observed despite the fact that women without post-surgery hypoparathyroidism were more affected by co-existing conditions, the team noted.

“This indicated a strong importance of HypoPT disease on QoL in this study population,” the researchers wrote.

In addition, women with chronic hypoparathyroidism more often underwent thyroidectomy due to overproduction of thyroid hormones (known as toxic disease) than those with normal parathyroid function (64.3% vs. 25%).

Among those with toxic disease, 87.5% had Graves’ disease, an autoimmune condition that often makes it difficult for surgeons to find the parathyroid glands and preserve their blood supply during thyroidectomy.

While the absence of a group of healthy individuals prevented the assessment of hypothyroidism’s impact on quality of life, the data suggest that a combination of hypoparathyroidism and hypothyroidism “have a greater impact on QoL than HypoPT itself in accordance with comparable studies,” the researchers wrote.

“There is a need for more focus and better treatment of patients experiencing chronic HypoPT after surgery,” the team added.

Future studies in larger patient populations and using health-related quality of life measures more specific to hypoparathyroidism are needed to confirm these findings, the researchers said.