Hypoparathyroidism Linked to Reduced Health-related Quality of Life
Patients with hypoparathyroidism experience reduced health-related quality of life, as compared to those without the disease, regardless of blood calcium levels, according to a new study.
The authors of the study suggest that some of these health-related quality of life issues may be amended with the use of PTH analogs — a replacement for the parathyroid hormone (PTH) that is decreased in patients with hypoparathyroidism — particularly in patients with low blood calcium levels.
The study, “Low health-related quality of life in hypoparathyroidism and need for PTH-analogue,” was published in the journal Endocrine Connections.
Hypoparathyroidism is a disorder characterized by insufficient levels of PTH, which leads to low levels of calcium and high levels of phosphate in the bloodstream. These imbalances can lead to calcifications in the body, namely in the kidneys, parts of the brain, and the lenses of the eyes.
Additionally, patients with hypoparathyroidism may experience physical and cognitive symptoms leading to a decrease in their health-related quality of life (HRQoL).
To shed more light on this matter, researchers in Sweden investigated the prevalence of hypoparathyroidism, and the HRQoL and mortality rates of those diagnosed with the disease.
Researchers hypothesized “that patients with HypoPT [hypoparathyroidism] have impaired HRQoL, higher morbidity and mortality, compared to the general population.”
The study involved 203 patients with hypoparathyroidism followed at the Sahlgrenska University Hospital in Gothenburg between 2007 and 2020, and compared them to 414 healthy individuals from the same region (control group).
The calculated prevalence of hypoparathyroidism was about 20.5 cases per 100,000 people across all causes, including post-surgical causes and genetic mutations. Most patients (80%) were women, with a median age of 58 years.
The main cause of the disorder in the group analyzed was neck surgery (80%, in 163 out of 203 patients), and 77% of the surgeries performed were for benign reasons, such as Grave’s disease (an immune disorder resulting in an overproduction of thyroid hormones) and non-toxic goiters (growths of the thyroid).
Nearly three-quarters (74%) of the patients required daily calcium and active vitamin D supplementation (an important vitamin for calcium absorption) to maintain calcium balance within the body and avoid issues associated with low calcium levels.
The 163 patients with hypoparathyroidism caused by surgery were older, tended to use higher doses of daily calcium supplementation, and used levothyroxine — a prescription for hypothyroidism (low thyroid hormone) — than those with hypoparathyroidism caused by other factors.
There were no other significant differences seen between those with post-operative hypoparathyroidism and those with the condition associated with other causes.
When comparing those with hypoparathyroidism to healthy individuals, the researchers found that creatinine (a byproduct of various cellular processes) and free T4 (thyroid hormone) were present in higher levels in those with hypoparathyroidism, while blood pressure was lower.
Total calcium, thyroid stimulating hormone (TSH), and PTH were also lower in those with hypoparathyroidism.
Additionally, the total number of medications used was higher in those with hypoparathyroidism — six per patient versus two in the control group — including calcium and vitamin D supplements. Furthermore, there was a slight increase in kidney dysfunction in patients with hypoparathyroidism.
In turn, there were fewer fractures and no increase in mortality over the 2007–2020 time period in patients with hypoparathyroidism, as compared to the general population.
The participants’ health-related quality of life was then assessed using the SF-36 and the EQ5D-VAS, which are different self-reported assessments of patient health and quality of life.
Those with hypoparathyroidism reported lower HRQoL as compared to the general population based on both the physical component of the assessments (40.0 versus 51.2 in the general population) and the mental component (43.1 versus 56.1), regardless of the disease cause.
When patients were categorized based on calcium levels and HRQoL, 71% had impaired health-related quality of life independent of their calcium levels, and 48% had decreased HRQoL despite having the recommended calcium levels.
Only 22% of the patients with recommended calcium levels scored above the high well-being threshold using the EQ5D-VAS (a score greater than 80).
Meanwhile, low calcium levels and a high sense of well-being were present in 7% of the patients, and low calcium levels and a low sense of well-being were present in 23%.
The team suggested that those with low calcium levels and a low sense of well-being were the most likely candidates to benefit from treatment with PTH analogs. Similar assessments, combining calcium levels and sense of well-being, have been used in previous studies to estimate the need for PTH analogs.
Overall, “HRQoL was markedly lower in patients with HypoPT than in controls and independent of serum calcium levels,” the researchers wrote, adding that “HRQoL, together with laboratory findings, seems to be an important variable to take into consideration when the treatment approach is to be decided.”
PTH analogs “could be considered at least among patients with both low HRQoL and low calcium levels,” the researchers wrote.