Parathyroid hormone (PTH) plays an important role in regulating a number of physiological functions, including control of calcium and phosphate, activating vitamin D, and maintaining normal bone turnover. Patients with low levels of PTH or hypoparathyroidism have a number of irregularities, including low serum calcium, high serum phosphate, increased urinary calcium excretion, decreased urinary phosphorus excretion, and low active vitamin D. PTH deficiency can also disrupt skeletal homeostasis leading to bone abnormalities
These physiological disruptions can have a profound affect on the person’s health and quality life. In the recently published
PARADOX study by Hadker et al in the July issue of Endocrine Practice, the authors asked 374 adults with hypoparathyroidism how the condition has impacted their lives.
The web-based questionnaire focused on demographics, diagnosis perceptions, current attitudes, medical management, current symptoms, acute episodes, comorbidities, personal life, and employment.
Key findings from the study were:
Patients reported visiting a mean of 6 (±8) physicians before and after their diagnosis
56% strongly agreed with feeling unprepared to manage the condition at diagnosis
60% strongly agreed that controlling their hypoparathyroidism was harder than expected
70% strongly agreed and that they were concerned about long-term complications of their current medications
72% had experienced more than 10 symptoms in the preceding 12 months, despite current management regimens
Mean duration of symptoms was 13±9 hours/day
79% required hospital stays or emergency department visits. 45% reported significant interference with their lives
85% reported an inability to perform household activities
20% experienced a disease-associated change in employment status
The most commonly reported physical symptoms were fatigue (82%), muscle pain/cramping (78%), paresthesia (76%), tetany (70%), joint or bone pain (67%) and pain or weakness in the extremities (53%)
Emotional symptoms commonly reported included anxiety (59%) and depression (53%). The most common cognitive symptoms were mental lethargy (72%), inability to concentrate (65%), memory loss (61.5%) and sleep disturbances (57%).
The authors of the study concluded “Patients with hypoparathyroidism have a high burden of illness and experience a broad spectrum of symptoms, with a multidimensional impact on their lives.”
In a press release
announcing the study, NPS Pharmaceutics, who are sponsors of the PARADOX study and who have a hypoparathyroidism treatment in development (Natpara) noted that the “findings also suggest that the burden of illness associated with hypoparathyroidism goes beyond clinical symptoms. The current standard of care for hypoparathyroidism is aimed at short-term symptom management with large doses of oral calcium and active vitamin D. The long-term use of this regime may put patients at risk of complications including soft tissue calcification, kidney stones, nephrocalcinosis, hypercalcemia, hypercalciuria and renal failure. Among patients managed with large doses of calcium and vitamin D, 69% experienced comorbidities including heart arrhythmias (66%) kidney stones (35.5%) and bone fractures (16%). “
Data Confirms What Many Suspected
The sobering results of the study validated what patient advocates of the condition already believed. James Sanders, president of the Hypoparathyroidism Association said, “We have heard from many patients about the challenges of living with the disorder. The PARADOX findings validate this feedback and also provide us with new insights about the impact of Hypoparathyroidism on health, home life and work. We hope that PARADOX can help us all be better advocates for patients living with this rare disorder.”
Presently, there is no approved treatment for hypoparathyroidism and current management seeks to control symptoms with oral calcium and active vitamin D (calcitriol or alphacalcidol). NPS Pharmaceuticals has filed a BLA for Natpara with the U.S. Food and Drug Admininstration (FDA). A review
of the Natpara BLA is scheduled for September 12, 2014 and a PDUFA Date is scheduled for October 24, 2014.
For more information about hypoparathyroidism, visit http://www.hypopara.org
For more information about NPS Pharmaceuticals and Natpara, visit www.NPSP.com
Hadker N, Egan J, Sanders J, Lagast H, Clarke BL. Understanding the burden of illness associated with hypoparathyroidism reported among patients in the Paradox study. Endo Pract.