Prevalence and incidence of hypoparathyroidism in the United States using a large claims database

Prevalence and characteristics of postoperative and nonoperative chronic hypoparathyroidism in Japan: a nationwide retrospective analysis

Hypoparathyroidism is a rare endocrine disorder characterized by low serum calcium and elevated serum phosphorus levels. Patients who do not recover parathyroid function after surgeries or have nonsurgical causes involving congenital and metabolic diseases, require long-term use of active vitamin D and calcium supplementation as conventional therapy in Japan. This study aimed to estimate prevalence of chronic hypoparathyroidism and investigate its disease etiology, patient characteristics, and treatment in Japan, using a health insurance claim database. Individuals who were available in the 4-yr observation period spanning 2015-2018 (2015-2017 for look-back and 2018 for prevalence estimation) were eligible for the denominator. Chronic hypoparathyroidism was defined as individuals who had both a record of prescription of conventional therapy for hypoparathyroidism in 2018 and a record of relevant surgery, radiotherapy, or disease at least 6 mo apart. Among the denominator (N = 2 241 717), 509 patients with chronic hypoparathyroidism were identified (mean age of 49 yr). The standardized prevalence of chronic hypoparathyroidism in 2018 was 38.3 (95% CI: 33.4-43.6) per 100 000 individuals, with 37.0 (32.2-42.3) and 1.2 (0.8-2.0) per 100 000 for postoperative and nonoperative causes, respectively. Six percent of the patients had chronic kidney disease as a comorbidity. Chronic hypoparathyroidism had heterogenous causes, with thyroid malignancy and 22q11.2 deletion syndrome being the most common postoperative and nonoperative causes, respectively. The mean duration of prescribed vitamin D and calcium was 963 and 629 d, respectively, during the 4-yr period. The prevalence of chronic hypoparathyroidism was similar but slightly higher than estimates reported for the United States and Europe, which may be due to the differences in study designs and high healthcare accessibility in Japan. Our study suggests that there is a nonnegligible number of patients, ~48 500 patients, with chronic hypoparathyroidism in Japan.

Bone development in fetuses with intrauterine growth restriction caused by maternal endocrine-metabolic dysfunctions

Intrauterine growth restriction (IUGR) affects a large proportion of infants, particularly in underdeveloped countries. Among the main causes of IUGR, maternal endocrine-metabolic dysfunction is highlighted, either due to its high incidence or due to the severity of the immediate and mediated changes that these dysfunctions cause in the fetus and the mother. Although the effects of endocrine and metabolic disorders have been widely researched, there are still no reviews that bring together and summarize the effects of these conditions on bone development in cases of IUGR. Therefore, the present literature review was conducted with the aim of discussing bone changes observed in fetuses with IUGR caused by maternal endocrine-metabolic dysfunction. The main endocrine dysfunctions that occur with IUGR include maternal hyperthyroidism, hypothyroidism, and hypoparathyroidism. Diabetes mellitus, hypertensive disorders, and obesity are the most important maternal metabolic dysfunctions that compromise fetal growth. The bone changes reported in the fetus are, for the most part, due to damage to cell proliferation and differentiation, as well as failures in the synthesis and mineralization of the extracellular matrix, which results in shortening and fragility of the bones. Some maternal dysfunctions, such as hyperthyroidism, have been widely studied, whereas conditions such as hypoparathyroidism and gestational hypertensive disorders require further study regarding the mechanisms underlying the development of bone changes. Similarly, there is a gap in the literature regarding changes related to intramembranous ossification, as most published articles only describe changes in endochondral bone formation associated with IUGR. Furthermore, there is a need for more research aimed at elucidating the late postnatal changes that occur in the skeletons of individuals affected by IUGR and their possible relationships with adult diseases, such as osteoarthritis and osteoporosis.

Cost-Effectiveness of Parathyroid Cryopreservation and Autotransplantation

Importance

Delayed autotransplantation of cryopreserved parathyroid tissue (DACP) is the only surgical treatment for permanent postoperative hypoparathyroidism. Studies suggest that only a small minority of cryopreserved samples are ultimately autotransplanted with highly variable outcomes. For these reasons, many have questioned the economic utility of the process, although, to the authors' knowledge, this has never been formally studied.

Objective

To report the clinical outcomes of parathyroid cryopreservation and DACP at a large academic institution and to determine the cost-effectiveness of this treatment.

Design, Setting, and Participants

An institutional review board-approved, retrospective review of patients at a single institution who underwent DACP over a 17-year period was conducted with a median follow-up of 48.2 months. A forward-looking cost-utility analysis was then performed to determine the economic utility of cryopreservation/DACP vs usual care (monitoring and supplementation). Patients who had parathyroid tissue in cryopreserved storage between August 2005 to September 2022 at a single-center, academic, quaternary care center were identified.

Exposure

Parathyroid cryopreservation and DACP.

Main Outcomes and Measures

Graft functionality, clinical outcomes, and cost utility using a willingness-to-pay threshold of $100 000 per quality-adjusted life-year (QALY).

Results

A total of 591 patients underwent cryopreservation. Of these, 10 patients (1.7%; mean [SD] age, 45.6 [17.9] years; 6 male [60%]) underwent DACP. A minority of autografts (2 [20%]) were subsequently fully functional, one-half (5 [50%]) were partially functional, and 3 (30%) were not functional. The cost-utility model estimated that at a large academic center over 10 years, the additional cost of 591 patients undergoing cryopreservation and 10 patients undergoing autotransplantation would be $618 791.64 (2022 dollars) and would add 8.75 QALYs, resulting in a cost per marginal QALY of $70 719.04, which is less than the common willingness-to-pay threshold of $100 000/QALY.

Conclusions and Relevance

The reimplantation rate of cryopreserved tissue was low (<2%), but when implanted, autografts were at least partially functional 70% of the time. In the first-ever, to the authors' knowledge, formal cost analysis for this treatment, results of the current model suggest that cryopreservation and autotransplantation were cost-effective compared with the usual care for hypoparathyroidism at a large, academic institution. It is recommended that each surgical center consider whether the economic and logistical commitments necessary for cryopreservation are worthwhile for their individual needs.

Preclinical development of EXT608, an investigational parathyroid hormone derivative with extended half-life for the treatment of hypoparathyroidism

Hypoparathyroidism, a deficiency of parathyroid hormone (PTH), results in hypocalcemia, hyperphosphatemia, and hypercalciuria. The disease is poorly controlled by calcium and vitamin D supplements or native PTH(1-84) replacement therapy. A version of PTH is being developed using D-VITylation technology, whereby vitamin D is conjugated to a therapeutic peptide, which confers a long plasma half-life by virtue of binding to the abundant vitamin D binding protein (DBP). D-VITylation of PTH caused no reduction in activity at the PTHR1 receptor, and resulted in a plasma elimination half-life of 7-15 h in rats and 24-32 h in cynomolgus monkeys. Analysis of steady-state pharmacokinetics as a function of dose showed flat profiles with smaller peak:trough ratios at low doses, indicative of slower subcutaneous absorption. In thyroparathyroidectomized (TPTx) rats, PTH(1-34)-vitamin D conjugates restored serum calcium and phosphate levels into the normal range over the 24 h dosing period, and increased bone turnover markers and reduced bone mineral density. Urinary calcium was initially elevated, but normalized by the end of treatment on day 27. In healthy monkeys, a single dose of PTH(1-34)-vitamin D conjugates elevated serum calcium levels above the normal range for a period of 24-48 h while simultaneously reducing urinary calcium. Therefore, the lead compound, EXT608, is a promising candidate as a therapeutic that can truly mimic the endogenous activity of PTH and warrants further study in patients with hypoparathyroidism.

Economic burden of patients with post-surgical chronic and transient hypoparathyroidism in the United States examined using insurance claims data

BACKGROUND

Hypoparathyroidism (HP) is a rare endocrine disease commonly caused by the removal or damage of parathyroid glands during surgery and resulting in transient (tHP) or chronic (cHP) disease. cHP is associated with multiple complications and comorbid conditions; however, the economic burden has not been well characterized. The objective of this study was to evaluate the healthcare resource utilization (HCRU) and costs associated with post-surgical cHP, using tHP as a reference.

METHODS

This analysis of a US claims database included patients with both an insurance claim for HP and thyroid/neck surgery between October 2014 and December 2019. cHP was defined as an HP claim ≥ 6 months following surgery and tHP was defined as only one HP claim < 6 months following surgery. The cHP index date was the first HP diagnosis claim following their qualifying surgery claim, whereas the tHP index date was the last HP diagnosis claim following the qualifying surgery claim. Patients were continuously enrolled at least 1 year pre- and post-index. Patients' demographic and clinical characteristics, all-cause HCRU, and costs were descriptively analyzed. Total all-cause costs were calculated as the sum of payments for hospitalizations, emergency department, office/clinic visits, and pharmacy.

RESULTS

A total of 1,406 cHP and 773 tHP patients met inclusion criteria. The average age (52.1 years cHP, 53.5 years tHP) and representation of females (83.2% cHP, 81.2% tHP) were similar for both groups. Neck dissection surgery was more prevalent in cHP patients (23.6%) than tHP patients (5.3%). During the 1-2 year follow-up period, cHP patients had a higher prevalence of inpatient admissions (17.4%), and emergency visits (26.0%) than the reference group -tHP patients (14.4% and 21.4% respectively). Among those with a hospitalization, the average number of hospitalizations was 1.5-fold higher for cHP patients. cHP patients also saw more specialists, including endocrinologists (28.7% cHP, 15.8% tHP), cardiologists (16.7% cHP, 9.7% tHP), and nephrologists (4.6% cHP, 3.3% tHP).

CONCLUSION

This study demonstrates the increased healthcare burden of cHP on the healthcare system in contrast to patients with tHP. Effective treatment options are needed to minimize the additional resources utilized by patients whose HP becomes chronic.

[A case of severe hyperparathyroidism in clinical practice. Case report]

Disorders of the mineral balance often determine the symptoms, the severity of the course and the prognosis of many diseases. Primary hyperparathyroidism (PHPT) is a common endocrine disease caused by increased secretion of parathyroid hormone as a result of primary damage to the parathyroid glands. Diagnosis of PHPT is often difficult. Clinical signs of PHPT appear months or years after the onset of the disease, however, the presence of hypercalcemia serves as an early indication of the disease of the thyroid gland. Often, patients are observed for a long time by related specialists (rheumatologists, traumatologists-orthopedists, oncologists), which gives rise to a lot of problems consisting in the lack of adequate treatment and its result, the progression of the disease, disability, and a decrease in the quality of life. Often, patients are observed for a long time by related specialists (rheumatologists, orthopedic traumatologists, oncologists) under the "masks" of various pathologies (osteoporosis, recurrent urolithiasis, etc.), which gives rise to a lot of problems, consisting in an erroneous diagnosis, lack of adequate treatment and its result, progression of the disease, disability, and a decrease in the quality of life. Late diagnosis of PHPT leads to the development of severe complications (osteoporetic fractures, renal failure) and an increased risk of premature death. A clinical case of late diagnosis of PHPT at the stage of pronounced bone complications of the disease, which proceeded under the guise of osteoarthritis, is considered. According to the results of laboratory and instrumental studies, the following were revealed: hypercalcemia, a significant increase in the concentration of PTH, adenoma of the left lower parathyroid gland, hyperparathyroid osteodystrophy, and a decrease in bone mineral density. Surgical treatment was performed - selective parathyroidectomy with the development of hypocalcemia in the early postoperative period, which was stopped by taking calcium supplements and active vitamin D metabolites and is designed to help practitioners of various specialties to understand the issues of diagnosis of PHPT and effective care for patients.

Impact of autofluorescence for detection of parathyroid glands during thyroidectomy on postoperative parathyroid hormone levels: parallel multicentre randomized clinical trial

BACKGROUND

Techniques for autofluorescence have been introduced to visualize the parathyroid glands during surgery and to reduce hypoparathyroidism after thyroidectomy.

METHODS

This parallel multicentre RCT investigated the use of Fluobeam® LX to visualize the parathyroid glands by autofluorescence during total thyroidectomy compared with no use. There was no restriction on the indication for surgery. Patients were randomized 1 : 1 and were blinded to the group allocation. The hypothesis was that autofluorescence enables identification and protection of the parathyroid glands during thyroidectomy. The primary endpoint was the rate of low parathyroid hormone (PTH) levels the day after surgery.

RESULTS

Some 535 patients were randomized, and 486 patients received an intervention according to the study protocol, 246 in the Fluobeam® LX group and 240 in the control group. Some 64 patients (26.0 per cent) in the Fluobeam® LX group and 77 (32.1 per cent) in the control group had low levels of PTH after thyroidectomy (P = 0.141; relative risk (RR) 0.81, 95 per cent c.i. 0.61 to 1.07). Subanalysis of 174 patients undergoing central lymph node clearance showed that 15 of 82 (18 per cent) in the Fluobeam® LX group and 31 of 92 (33 per cent) in the control group had low levels of PTH on postoperative day 1 (P = 0.021; RR 0.54, 0.31 to 0.93). More parathyroid glands were identified during operation in patients who had surgery with Fluobeam® LX, and fewer parathyroid glands in the surgical specimen on definitive histopathology. No specific harm related to the use of Fluobeam® LX was reported.

CONCLUSION

The use of autofluorescence during thyroidectomy did not reduce the rate of low PTH levels on postoperative day 1 in the whole group of patients. It did, however, reduce the rate in a subgroup of patients. Registration number: NCT04509011 (http://www.clinicaltrials.gov).

Impairments in quality of life and predictors of symptom burden in patients with hypoparathyroidism: results from a population-based survey

PURPOSE

To investigate the quality of life (QoL) in patients with hypoparathyroidism (hypoPT) compared to the general population and to identify sociodemographic and clinical factors that are associated with symptom burden.

METHODS

Patients with a diagnosis of hypoPT participated in an online survey. Information regarding the survey was distributed by treating physicians or a self-help organization. Quality of life was assessed using the EORTC QLQ-C30 and symptom burden using the Hypoparathyroid Patient Questionnaire (HPQ28). Multivariate linear regression analysis was used to compare QoL of hypoPT patients with the general population (adjusted for age, sex, education)and to identify factors associated with symptom burden.

RESULTS

Altogether, 264 hypoPT patients provided information on QoL and symptom burden. HypoPT was associated with worse cognitive (β = -15.9; p < 0.01) and emotional functioning (β = -12.3; p = 0.04) compared to the general population. The highest symptom burden in hypoPT patients was observed for the domains loss of vitality (mean: 61.4; SD: 21.9), pain and cramps (mean: 43.7; SD: 26.5), and numbness and tingling sensations (mean: 38.9; SD: 30.0). Female gender was associated with a higher symptom burden across all nine domains of the HPQ28, while longer disease duration was associated with a lower symptom burden in neurovegetative symptoms, loss of vitality, depression and anxiety, and depressive symptoms.

CONCLUSION

HypoPT patients have impaired QoL compared to the general population. Being female is strongly associated with high symptom burden.

Hypoparathyroidism - management, information needs, and impact on daily living from the patients' perspective: results from a population-based survey

PURPOSE

Hypoparathyriodism (hypoPT) is a rare endocrine disorder. It is not known how hypoPT is managed in Germany or whether patients have unmet information needs or impairments in their daily living.

METHODS

HypoPT patients at a minimum of 6 months' post-diagnosis were invited to participate in an online survey through their treating physician or through patient organizations. An extensive questionnaire, which was developed and pilot-tested with hypoPT patients, was administered.

RESULTS

A total of 264 patients with a mean age of 54.5 years (SD: 13.3), 85.2% female and 92% with postsurgical hypoPT, participated in the study. In total, 74% of the patients reported regular monitoring of serum calcium at least every 6 months, with lower control frequencies for phosphate (47%), magnesium (36%), creatinine (54%), and parathyroid hormone (50%), and 24-h urine calcium excretion (36%) on a yearly basis. Information on symptoms of hypo- and hypercalcemia was available in 72 and 45% of the patients. Information needs were related to the disease and its treatment as well as to nutrition, physical activities/sports, and support opportunities. Statistically significant differences for all information needs in association with symptom burden were observed. Hospitalization for hypocalcemia was reported by 32%, nutritional impairments (38%) or impact on work ability (52%) was available among patients with hypoPT.

CONCLUSION

HypoPT patients experience impairments in daily living and report unmet information needs. Patient and physician education regarding hypoPT is one of the key concepts for improving the management of patients with hypoPT.

Effect of intraoperative active exploration of parathyroid glands to reduce the incidence of postoperative hypoparathyroidism, and risk factors of hypoparathyroidism after total thyroidectomy: a single-center study

Background

The risk factors for hypoparathyroidism after thyroid surgery have not been fully identified. This study analyzes the risk factors of hypoparathyroidism before and after total thyroidectomy.

Methods

We retrospectively collected the clinical data of 289 patients who underwent total thyroidectomy at the Thyroid Surgery Center of Lishui Central Hospital from June 2018 to June 2020. For the anatomy and protection of parathyroid glands during the operation, one group of patients used the parathyroid avoidance method, and the other group used the active exploration method. Various risk factors affecting parathyroid dysfunction were studied using logistic regression models.

Results

A total of 289 patients were included in this study. The average age of patients was 47.21 ± 11.78 years, including 57 males (19.7%) and 232 females (80.3%). There were 149 (51.6%) patients with transient hypoparathyroidism and 21 (7.3%) with permanent hypoparathyroidism. The main risk factors of hypoparathyroidism were parathyroid avoidance method (P = 0.005), parathyroid autotransplantation (P = 0.011), bilateral central neck lymph node dissection (CND) (P = 0.001), lymphatic metastasis (P = 0.039), and parathyroid in the specimen (P = 0.029). The main risk factors associated with permanent hypoparathyroidism were bilateral CND (P = 0.038), lymphatic metastasis (P = 0.047), parathyroid hormone (PTH) < 1.2 pg/ml within three days after surgery (P = 0.006).

Conclusion

Hypoparathyroidism is common but mostly transient after bilateral total thyroidectomy. Compared with parathyroid avoidance method, the active exploration method during operation may reduce the incidence of postoperative hypoparathyroidism. PTH <1.2 pg/ml within three days after surgery was predictive in patients with permanent hypoparathyroidism.

A Phase I Randomized Trial of Once-Daily Versus Twice-Daily Recombinant Human Parathyroid Hormone (1-84) for Hypoparathyroidism

Recombinant human parathyroid hormone (1-84), rhPTH(1-84), is an approved adjunctive treatment to oral calcium and active vitamin D for adult patients with hypoparathyroidism; however, there is limited information on the effect of twice daily (BID) dosing of rhPTH(1-84). This was a phase I, open-label, randomized, crossover, multicenter study conducted in adult patients with chronic hypoparathyroidism. The primary objective was to assess the pharmacokinetic profile and pharmacodynamic effects of 1 day of treatment with rhPTH(1-84) administered subcutaneously at 25 μg BID, 50 μg BID, and 100 μg once daily (QD) with or without supplemental oral calcium. Safety and tolerability were evaluated as secondary objectives. In total, 33 patients with chronic hypoparathyroidism completed the study. Treatment with rhPTH(1-84), both BID and QD, over the short-term maintained serum calcium, lowered serum phosphorus, decreased urinary calcium excretion, and increased urinary phosphorus excretion. The decrease in urinary calcium excretion was numerically greater for BID than QD. Generally, baseline-adjusted pharmacokinetic parameters including area under the curve and maximum observed concentration increased with increasing rhPTH(1-84) dose, although this effect was not dose proportional. No new safety findings were observed. Our study revealed no differences thought to be clinically meaningful in pharmacokinetic or pharmacodynamic parameters with BID versus QD rhPTH(1-84) dosing. Future long-term studies are warranted to further elucidate the effects of alternative dosing strategies. © 2023 Takeda Development Center Americas, Inc and The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Recent Trends in Hypoparathyroidism-Related Inpatient and Emergency Department Admissions and Costs in the United States

Hypoparathyroidism (HypoPT) is a rare disease associated with high morbidity. Its economic impact is not well understood. This retrospective, cross-sectional study used data from the United States-based National Inpatient Sample and the Nationwide Emergency Department Sample from 2010 to 2018 to quantify overall trends in number, cost, charges, and length of stay (LOS) for inpatient hospitalizations and number and charges for emergency department (ED) visits for HypoPT-related and for non-HypoPT-related causes. Additionally, the study estimated the marginal effect of HypoPT on total inpatient hospitalization costs and LOS as well as ED visit charges. Over the observed period, a mean of 56.8-66.6 HypoPT-related hospitalizations and 14.6-19.5 HypoPT-related ED visits were recorded per 100 000 visits per year. Over this period, the rate of HypoPT-related inpatient hospitalizations and ED visits increased by 13.5% and 33.6%, respectively. The mean LOS for HypoPT-related hospitalizations was consistently higher than for non-HypoPT-related causes. Total annual HypoPT-related inpatient hospitalization costs increased by 33.6%, and ED visit charges increased by 96.3%. During the same period, the annual costs for non-HypoPT-related hospitalizations and charges for ED visits increased by 5.2% and 80.3%, respectively. In all years, HypoPT-related hospital encounters resulted in higher charges and costs per individual visit than non-HypoPT-related encounters. The marginal effect of HypoPT on inpatient hospitalization costs and LOS, and on ED charges, increased over the period of observation. This study demonstrated that HypoPT was associated with substantial and increasing healthcare utilization in the United States between 2010 and 2018.

Seizures in activating calcium-sensing receptor antibodies positive autoimmune hypoparathyroidism and preponderance of steroids therapy: A case report

A 55-year-old female patient presented with generalized tonic-clonic seizures. Laboratory evaluation revealed low calcium (4.9 mg/dl), low PTH (0.9 pg/ml), and positive activating CaSR antibodies. The condition was diagnosed as autoimmune hypoparathyroidism. Calcium and vitamin D supplements did not correct the patient's hypocalcemia. The addition of prednisone to vitamin supplements showed a better response and corrected the hypocalcemia. The patient remained in seizure-free for one year.

How low is too low? Intraoperative parathyroid hormone decline in normohormonal primary hyperparathyroidism

BACKGROUND

In normohormonal primary hyperparathyroidism, parathyroid hormone levels are normal but inappropriately elevated for the degree of hypercalcemia. The study goals were to determine intraoperative parathyroid hormone parameters predictive of (1) cure and (2) hypocalcemia in this subgroup.

METHODS

We performed a retrospective cohort study comparing patients who underwent parathyroidectomy (2002-2019) for normohormonal and classic primary hyperparathyroidism. The primary outcomes were cure (calcium <10.3 mg/dL) and hypocalcemia (≤8.4 mg/dL) ≥6 months postoperatively.

RESULTS

In the study, 127 of 1,087 patients (11.7%) had normohormonal primary hyperparathyroidism. The groups experienced similar rates of cure (91.3% vs 94.1%, P = .23) and hypocalcemia (3.9% vs 2.9%, P = .53). However, intraoperative parathyroid hormone decline in cured patients was lower in those with normohormonal primary hyperparathyroidism (66.4% vs 84.5%, P < .0001). Receiver operating characteristic curves provided Youden's indices of 52% and 75% (cure) and 75% and 88% (hypocalcemia) for patients with normohormonal and classic primary hyperparathyroidism, respectively. Cure rates with ≥50% intraoperative parathyroid hormone decline were similar (94.1% vs 95.0%, P = .72), but hypocalcemia was more prevalent in patients with normohormonal primary hyperparathyroidism and ≥70% intraoperative parathyroid hormone decline (10.4% vs 3.3%, P = .01).

CONCLUSION

In patients with normohormonal primary hyperparathyroidism, intraoperative parathyroid hormone declines of ≥50% and ≥70% were predictive of postoperative cure and hypocalcemia, respectively. These parameters may inform intraoperative decision making and postoperative management.

Epidemiology and Financial Burden of Adult Chronic Hypoparathyroidism

Chronic hypoparathyroidism is characterized by low serum calcium, increased serum phosphorus, and inappropriately low or decreased serum parathyroid hormone. This rare disorder is associated with a variety of complications. The prevalence, incidence, mortality, financial burden, and epidemiology of complications of this disorder are not well understood. This narrative review summarizes current information on the epidemiology and complications of chronic hypoparathyroidism. The reported prevalence of chronic hypoparathyroidism ranges from 6.4-37/100,000, and the incidence is reported to be 0.8-2.3/100,000/year. Mortality is not increased in studies from Denmark or South Korea but was increased in studies from Scotland and Sweden. The financial burden of this disorder is substantial because of increased health care resource utilization in two studies but not well quantitated. Recognized complications include hypercalciuria, nephrocalcinosis, kidney stones, and chronic kidney disease; low bone turnover and possibly upper extremity fractures; cardiac and vascular calcifications; basal ganglia calcifications, cataracts, infections, neuropsychiatric complications, and difficulties with pregnancy. This review concludes that chronic hypoparathyroidism is a rare disorder associated with significant morbidity that may not increase overall mortality but is associated with a substantial financial burden. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Etiology and Pathophysiology of Hypoparathyroidism: A Narrative Review

The approach utilized a systematic review of the medical literature executed with specifically designed criteria that focused on the etiologies and pathogenesis of hypoparathyroidism. Enhanced attention by endocrine surgeons to new knowledge about parathyroid gland viability are reviewed along with the role of intraoperative parathyroid hormone (ioPTH) monitoring during and after neck surgery. Nonsurgical etiologies account for a significant proportion of cases of hypoparathyroidism (~25%), and among them, genetic etiologies are key. Given the pervasive nature of PTH deficiency across multiple organ systems, a detailed review of the skeletal, renal, neuromuscular, and ocular complications is provided. The burden of illness on affected patients and their caregivers contributes to reduced quality of life and social costs for this chronic endocrinopathy. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Bioactive, full-length parathyroid hormone delivered using an adeno-associated viral vector

Delivering the parathyroid hormone (PTH) gene has been attempted preclinically in a handful of studies, but delivering full-length PTH (1-84) using adeno-associated viral (AAV) vectors has not. Given the difficulty in achieving therapeutic levels of secreted proteins using gene therapy, this study seeks to determine the feasibility of doing so with PTH. An AAV vector was used to deliver human PTH driven by a strong promoter. We demonstrate the ability to secrete full-length PTH from various cell types in vitro. PTH secretion from hepatocytes was measured over time and a fluorescent marker was used to compare the secretion rate of PTH in various cell types. Potency was measured by the ability of PTH to act on the PTH receptors of osteosarcoma cells and induced proliferation. PTH showed potency in vitro by inducing proliferation in two osteosarcoma cell lines. In vivo, AAV was administered systemically in immunocompromised mice which received xenografts of osteosarcoma cells. Animals that received the highest dose of AAV-PTH had higher liver and plasma concentrations of PTH. All dosing groups achieved measurable plasma concentrations of human PTH that were above the normal range. The high-dose group also had significantly larger tumors compared to control groups on the final day of the study. The tumors also showed dose-dependent differences in morphology. When looking at endocrine signaling and endogenous bone turnover, we observed a significant difference in tibial growth plate width in animals that received the high-dose AAV as well as dose-dependent changes in blood biomarkers related to PTH. This proof-of-concept study shows promise for further exploration of an AAV gene therapy to deliver full-length PTH for hypoparathyroidism. Additional investigation will determine efficacy in a disease model, but data shown establish bioactivity in well-established models of osteosarcoma.

UK national chronic hypoparathyroidism audit

OBJECTIVES

Individuals with chronic hypoparathyroidism may experience suboptimal medical care with high frequency of unplanned hospitalisation and iatrogenic harm. In 2015 the European Society for Endocrinology published consensus guidelines on the management of chronic hypoparathyroidism. We set out to audit compliance with these guidelines.

METHODS

Using these recommendations as audit standards we worked with the Society for Endocrinology and Parathyroid UK to conduct a national audit of management of chronic hypoparathyroidism in the United Kingdom. Endocrine leads in 117 endocrine departments were invited to participate in the survey by completing a data collection tool on up to 5 sequential cases of chronic hypoparathyroidism seen in their outpatient clinics in the preceding 12 months. Data were collected on 4 treatment standards and 9 monitoring standards. Data on hospitalisations and Quality of Life monitoring were also collected.

RESULTS

Responses were received from 22 departments giving a response rate of 19%, concerning 80 individual cases. The mean age of subjects was 48.4 years. The main findings were that the commonest cause of hypoparathyroidism was post surgical (66.3%). Treatments taken by the group included activated vitamin D analogues (96.3%), oral calcium salts (66.3%), vitamin D supplements (17.5%), thiazide diuretics (5%) and rhPTH_1-34 (1.3%). Compliance with the audit standards varied between 98.8% and 60% for the treatment standards and between 91.3% and 20% for the monitoring standards. Some of the areas of weakness revealed include low rates of 24 h urinary calcium excretion monitoring, serum magnesium monitoring and low rates of renal imaging where indicated. In addition and importantly, 16.3% of subjects had experienced at least one hospital admission in the preceding 12 months.

CONCLUSION

We conclude that further improvements in the UK national standard of management of chronic hypoparathyroidism should be made and that this will benefit both quality of life, morbidity and potentially mortality in this group of patients.

Kidney Complications and Hospitalization in Patients With Chronic Hypoparathyroidism: A Cohort Study in Sweden

CONTEXT

Kidney complications may be considerably higher in patients with chronic hypoparathyroidism (hypoPT) treated with activated vitamin D and calcium supplementation.

OBJECTIVE

We aimed to investigate the risk of chronic kidney disease (CKD), urolithiasis, and hospitalization in patients with chronic hypoPT.

METHODS

In this population-based cohort study in Sweden, national registries (Swedish National Patient Register, Swedish Prescribed Drug Register, and Total Population Register, 1997-2018) were used to identify patients with chronic hypoPT and controls matched by sex, age, and county of residence. We determined time to CKD and urolithiasis diagnosis, and incidence rates of hospitalization.

RESULTS

A total of 1562 patients with chronic hypoPT without preexisting CKD and 15 620 controls were included. The risk of developing CKD was higher in patients with chronic hypoPT compared with controls (hazard ratio [HR] 4.45; 95% CI, 3.66-5.41). In people without prior urolithiasis (n = 1810 chronic hypoPT and n = 18 100 controls), the risk of developing urolithiasis was higher in patients with chronic hypoPT (HR 3.55; 95% CI, 2.84-4.44) compared with controls. Patients with chronic hypoPT had higher incidence rates for all-cause hospitalization (49.59; 95% CI, 48.50-50.70, per 100 person-years vs 28.43; 95% CI, 28.15-28.71, respectively) and for CKD (3.46; 95% CI, 3.18-3.76, per 100 person-years vs 0.72; 95% CI, 0.68-0.77, respectively), compared with controls. Men with hypoPT appear to have a higher risk of CKD than women.

CONCLUSION

Patients with chronic hypoPT had an increased risk of CKD, urolithiasis, and hospitalization compared with controls.

What are predictors of impaired quality of life in patients with hypoparathyroidism?

CONTEXT

Hypoparathyroidism (hypoPT) is a rare endocrine disorder. Little is known about what factors are associated with potential quality of life (QOL) impairments.

DESIGN

HypoPT patients at a minimum of 6 months' post diagnosis were invited to participate in an online survey through their treating physician or through self-help organisations METHODS: Impairments of clinical importance in QOL were considered present if the score of the respective functioning scale of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 exceeded a pre-defined threshold. Symptom burden was assessed using the HPQ-28. Multivariate logistic regression was used to identify factors associated with impairments in QOL.

RESULTS

Data were available for 264 hypoPT patients. Impairments of clinical importance in QOL were reported for 40.4% in role functioning (RF), 40.6% in social functioning (SF), 60.8% in physical functioning (PF), 65.5% in cognitive functioning (CF) and 76.0% in emotional functioning (EF). Higher odds for reporting impaired QOL were seen for higher symptom burden (for almost all domains) and for being unable to work (for PF, RF and SF). Surgery for thyroid cancer being the cause of hypoPT was associated with lower odds in PF for patients and in PF and CF for patients with surgery for other thyroid-related diseases being the hypoPT cause.

CONCLUSIONS

HypoPT needs to be recognised as a disease which might be associated with impaired QOL and affect daily living. Symptom management is crucial for improving QOL in hypoPT patients but socioeconomic factors like work-ability need to be considered when treating hypoPT patients.

Preoperative supplementation of calcitriol and calcium relieves symptom and extent of hypocalcemia in patients undergoing total thyroidectomy and bilateral central compartment neck dissection: A prospective, randomized, open-label, parallel-controlled clinical study

Background

Hypocalcemia is the most common complication that challenges surgeons performing total thyroidectomy. Conventional postoperative calcium and calcitriol supplement has been reportedly effective; however, a time lag has been reported before taking effect. Therefore, the role of preoperative strategy is yet to be determined.

Study design

In this prospective, randomized, open-label, parallel-controlled phase II clinical study (registration number: ChiCTR2200059815), a short-term preoperative administration of calcitriol and calcium was proposed in 210 patients undergoing total thyroidectomy and bilateral central compartment neck dissection. Patients were recruited and randomized (1:1:1) into three groups: (A) combined (preoperative calcitriol and calcium), (B) calcium only (preoperative calcium only), and (C) control (no preoperative intervention). Finally, a total of 172 patients were qualified for final analysis.

Results

Our data showed that 16 of 63 patients (25.4%) in the combined group had symptomatic hypocalcemia, whereas more patients from the control group (25 of 57 patients, 43.9%, P = 0.033) had symptomatic hypocalcemia. Further, the postoperative calcium level in the combined group is higher than in the control group (2.15 ± 0.15 vs. 2.09 ± 0.15 mmol/L, P = 0.031). Moreover, patients from the combined group showed lower calcium rates of <2.00 mmol/L (12.7% vs. 28.1%, P = 0.036). Remarkably, compared with the control group, patients with transient hypoparathyroidism in the combined group showed fewer rates for both symptomatic and biochemical hypocalcemia (28.6% vs. 61.1% for symptomatic hypocalcemia; 47.6% vs. 75% for biochemical hypocalcemia). Patients without transient hypoparathyroidism in all three groups showed no significant difference in rates for either symptomatic or biochemical hypocalcemia, indicating that this preoperative strategy is only effective for patients with transient hypoparathyroidism. We did not observe such beneficial effects in patients from the calcium group.

Conclusions

Preoperative administration of calcitriol and calcium could reduce symptomatic and biochemical hypocalcemia, especially for those with transient hypoparathyroidism. Moreover, this maneuver could be recommended as a clinical routine in patients undergoing total thyroidectomy and bilateral central compartment neck dissection.

Clinical Trial Registration

http://www.chictr.org.cn/edit.aspx?pid=164316&htm=4, identifier ChiCTR2200059815.

Lower Risk of Cardiovascular Events in Adult Patients with Chronic Hypoparathyroidism Treated with rhPTH(1-84): A Retrospective Cohort Study

Introduction

Patients with chronic hypoparathyroidism are at increased risk of cardiovascular disease. This study evaluated the risk of developing cardiovascular conditions over a period of 5 years in adult patients with chronic hypoparathyroidism treated with recombinant human parathyroid hormone (1–84), rhPTH(1–84), compared with a historical control cohort of patients not treated with rhPTH(1–84).

Methods

This retrospective cohort study comprised patients with chronic hypoparathyroidism treated with rhPTH(1–84) in the REPLACE (NCT00732615), RELAY (NCT01268098), and RACE (NCT01297309) clinical trials, and controls selected from the IBM^® Explorys electronic medical record database (January 2007–August 2019) who did not receive parathyroid hormone but who had enrollment criteria similar to those for the clinical trials. Cardiovascular outcomes were the first diagnosis of cerebrovascular, coronary artery, peripheral vascular disease, or heart failure during the study period.

Results

We evaluated 113 adult patients with chronic hypoparathyroidism treated with rhPTH(1–84) and 618 control patients who did not receive rhPTH(1–84). Over the 5-year follow-up period, 3.5% of patients (n = 4) in the rhPTH(1–84) cohort had a cardiovascular event compared with 16.3% (n = 101) in the control cohort. Kaplan–Meier analysis demonstrated that patients in the rhPTH(1–84) cohort had lower risk of experiencing a cardiovascular event compared with patients in the control cohort (P = 0.005). Multivariable analyses adjusted for baseline variables showed that patients in the rhPTH(1–84) cohort had 75% lower risk for a cardiovascular event compared with patients in the control cohort (adjusted hazard ratio, 0.25 [95% CI 0.08–0.81]; P = 0.020).

Conclusion

Long-term treatment with rhPTH(1–84) was associated with a lower risk of incident cardiovascular conditions compared with conventional therapy in patients with chronic hypoparathyroidism. Previous studies demonstrated that mineral homeostasis was maintained with lower use of calcium and active vitamin D when rhPTH(1–84) was added to conventional therapy. Future studies are needed to understand whether improved regulation of mineral homeostasis conferred by rhPTH(1–84) may provide long-term cardiovascular benefits to patients with chronic hypoparathyroidism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02198-y.

Teriparatide administration by the Omnipod pump: preliminary experience from two cases with refractory hypoparathyroidism

CONTEXT

Hypoparathyroidism (hypoPTH) in adults is mainly due to total thyroidectomy. Conventional therapies (calcium, active vitamin D) can fail to normalize calcemia, expose the patient to hypercalciuria and impact quality-of-life. Human parathormone (PTH) replacement therapy is a suitable option in these cases, although few clinical reports have been published so far.

METHODS

We describe two cases of patients with refractory postsurgical hypoPTH, in whom subcutaneous infusion of recombinant PTH (teriparatide) through the Omnipod® pump was initiated after failure of all other therapeutic options. Besides, we performed a review of literature of hypoPTH cases treated by continuous infusion of teriparatide.

RESULTS

Two women aged 46 and 61 years old failed to normalize calcemia either with conventional treatments (calcium 8 g/day + calcitriol 9 mcg/day and calcium 5 g/day + calcitriol 12 mcg/day) or with thrice daily subcutaneous injections of teriparatide. As a last resort, teriparatide infusion via Omnipod® device normalized their calcemia and allowed calcium/vitamin D withdrawal, with average teriparatide dose of 23 and 32 mcg/day, respectively. The flow of teriparatide was adapted according to a protocol based on measured calcemia, under medical supervision. In the literature, 15 adult cases (13 women, mean age 44.5 ± 5.2 years old) are reported. HypoPTH was consecutive to surgery in all of them. Mean dose of teriparatide administered was 25 ± 6 mcg/day with improvement of calcemia level and quality-of-life in all patients.

CONCLUSIONS

Continuous administration of teriparatide through Omnipod® appears as an efficient therapeutic option in refractory hypoPTH, whose administration to the patient can be assisted by medically-supervised protocol.

Parathyroid Allotransplantation: A Systematic Review

Background: To date, there is no satisfactory treatment for patients with calcium and vitamin D supplementation refractive hypoparathyroidism. Parathyroid allotransplantation by design is a one-time cure through its restoration of the parathyroid function and, therefore, could be the solution. A systematic literature review is conducted in the present paper, with the aim of outlining the possibilities of parathyroid allotransplantation and to calculate its efficacy. Additionally, various transplantation characteristics are linked to success. Methods: This review is carried out according to the PRISMA statement and checklist. Relevant articles were searched for in medical databases with the most recent literature search performed on 9 December 2021. Results: In total, 24 articles involving 22 unique patient cohorts were identified with 203 transplantations performed on 148 patients. Numerous types of (exploratory) interventions were carried out with virtually no protocols that were alike: there was the use of (non-) cryopreserved parathyroid tissue combined with direct transplantation or pretreatment using in vitro techniques, such as culturing cells and macro-/microencapsulation. The variability increased further when considering immunosuppression, graft histology, and donor–recipient compatibility, but this was found to be reported in its entirety by exception. As a result of the large heterogeneity among studies, we constructed our own criterium for transplantation success. With only the studies eligible for our assessment, the pooled success rate for parathyroid allotransplantation emerged to be 46% (13/28 transplantations) with a median follow-up duration of 12 months (Q1–Q3: 8–24 months). Conclusions: Manifold possibilities have been explored around parathyroid allotransplantation but are presented as a double-edged sword due to high clinical diverseness, low expertise in carrying out the procedure, and unsatisfactory study quality. Transplantations carried out with permanent immunosuppression seem to be the most promising, but, in its current state, little could be said about the treatment efficacy with a high quality of evidence. Of foremost importance in pursuing the answer whether parathyroid allotransplantation is a suitable treatment for hypoparathyroidism, a standardized definition of transplantation success must be established with a high-quality trial.

Prolonged ST segment and T-wave alternans with torsade de pointes secondary to hypocalcemia due to hypoparathyroidism: A case report

Hypoparathyroidism predisposes patients to hypocalcemia. Patients with hypoparathyroidism are thus at risk of electrocardiographic abnormalities, including T-wave alternans. T-wave alternans is poorly understood and lacks uniform diagnostic criteria. Its presence suggests myocardial electrical instability, and it has become an important sign for identifying patients at high risk of malignant arrhythmias and sudden cardiac death. We report a rare case of T-wave alternans with torsade de pointes due to hypocalcemia. The etiology of T-wave alternans may easily be overlooked. It should thus be thoroughly investigated to avoid misdiagnosis and poor outcomes.

Assessment of calcium and vitamin D medications adherence in patients with hypoparathyroidism after thyroidectomy

In this study, we found that patients with hypoparathyroidism had a problem with calcium medication compliance, and this problem increased with the duration of the disease. We also showed that patients are concerned about the possible side effects of drugs.

INTRODUCTION

In this study, we aimed to evaluate adherence to active vitamin D and calcium replacement in patients with post-surgical hypoparathyroidism.

METHODS

To elucidate the medication adherence, we performed a questionnaire survey using the six-item "Medication adherence questionnaire"(MAQ). The first, second, and sixth questions reflect the motivation status of the patients whereas the third, fourth, and fifth questions reflect the knowledge about the medication that is received. The responses are scored and patients are classified regarding their motivation to and knowledge about the particular drug.

RESULTS

Totally, 64 patients (male: 12/female: 52; mean age 48.6±11.6 years) who had post-operative hypoparathyroidism were included in our study. Median disease durance was 60 months (min-max: 12-295 months). We found that motivation score of calcium usage was significantly lower compared to vitamin D usage (p<0.001). The calcium motivation score was reversely correlated with disease duration (r= -0.256 and p=0.046). The most common worry about calcium usage was nephrotoxicity, and the most common worries about calcitriol treatment were kidney damage and polyuria. One-third of the patients were taking oral calcium and calcitriol less than the recommended dose.

CONCLUSION

One-third of patients lack motivation to use calcium whereas half of the patients experiences anxiety about drug-related side effects. This is a preliminary study showing that vital calcium and active vitamin D intake may be interrupted due to side effect anxiety.

Low health-related quality of life in hypoparathyroidism and need for PTH analog

OBJECTIVE

Hypoparathyroidism (HypoPT) is a rare endocrine disorder in which insufficient levels of parathyroid hormone (PTH) lead to low serum calcium (S-Ca) levels and muscular cramps. The aim was to study the health-related quality of life (HRQoL) and comorbidities in patients with HypoPT compared with the general population and to estimate the need of treatment with PTH analog.

DESIGN

Patients with HypoPT were identified and compared with a population sample. Short Form-36 (SF-36) and EuroQol-5 Dimensions Visual Analogue Scale questionnaires were used. All patients were followed up at the Sahlgrenska University Hospital outpatient clinic.

METHODS

From the medical records between 2007 and 2020, 203 patients with HypoPT were identified and compared with a population sample (n = 414) from the World Health Organization's (WHO) MONICA project, Gothenburg, Sweden. Of the 203 patients who met the diagnostic criteria, 164 were alive and 65% answered the HRQoL questionnaires.

RESULTS

Patients with HypoPT, 80% postsurgical, and controls had similar age (60 years) and sex distribution (80% women). Patients had lower SF-36 summary component scores for physical (40.0 (interquartile range (IQR): 21) vs 51.2 (IQR: 14.6); P < 0.001) and mental (43.1 (IQR:17.4) vs 56.1(IQR:13.3); P < 0.001) well-being, irrespective of etiology or calcium levels. Individuals with HypoPT had more medications and lower renal function but not higher mortality than controls. Low HRQoL together with low calcium was present in 23% of individuals with HypoPT.

CONCLUSION

HRQoL was markedly lower in patients with HypoPT than in controls and independent of S-Ca levels. Treatment with PTH analog could be considered at least among patients with both low HRQoL and low calcium levels.

Hypoparathyroidism and Fahr's syndrome: case series

Hypoparathyroidism (HP) is a rare metabolic disorder and causes hypocalcemia because parathyroid hormone secretion is inadequate to mobilize calcium from bone and reabsorb calcium from kidney and gut. Anterior neck surgery is the most common cause of acquired HP and autoimmune HP is the next most common form in adults. The duration, severity, and rate of development of hypocalcemia determine the clinical presentation. A variety of organs can be affected by calcification, more frequently kidneys, but also joints, eyes, skin, vasculature, and other organ systems and, although rarely seen, intracerebral calcifications. We report four cases of bilateral basal ganglia calcifications (BGC) also known as Fahr's syndrome related to hypoparathyroidism. Fahr's syndrome is characterized by bilateral symmetrical calcification of areas of the brain that control movements including basal ganglia, thalamus, and others; it is a rare inherited or sporadic neurological disorder with a prevalence of less than 1/1.000.000. Main symptoms related to bilateral BGC include extra-pyramidal and cerebellar disorders, cognitive impairment, epileptic seizures, and psychiatric changes. BGC has been established as a possible outcome of HP. Its prevalence, demonstrated in the HP cohorts, varied significantly from 12 up to 74%. Currently, computed tomography (CT) is the most valuable method for diagnosis. The treatment include symptomatic support and identification of causes, but there is no specific treatment limiting the progression of calcification in the basal ganglia. Especially in HP, an early treatment can prevent calcification and neurophysiological disorders.

The Russian Registry of Chronic Hypoparathyroidism

INTRODUCTION

Chronic hypoparathyroidism is a relatively rare disease associated with multicomponent medical therapy and various complications. The analysis of large databases of patients with chronic hypoparathyroidism is a necessary tool to enhance quality of medical care, as well as to determine the optimal clinical and therapeutic approaches, and prognostic markers of the disease.

THE AIM

of this study is to estimate the clinical and biochemical profile, long-term complications, medical therapy and disease control of the patients with chronic postsurgical and non-surgical hypoparathyroidism.

MATERIALS AND METHODS

the cross-sectional, observational, continuous study was based on the Russian Registry of patients with hypoparathyroidism. 544 patients from 63 regions of the Russian Federation were included in this study.

RESULTS

The majority of cases had postsurgical etiology (88.4%). Postsurgical hypoparathyroidism prevailed in females (р<0.001). About a half of patients had blood calcium and phosphorus targets, 56 and 52% respectively. Nephrolithiasis was confirmed in 32.5%, nephrocalcinosis - in 12.3% of cases. The risk of nephrocalcinosis/nephrolithiasis increased by 1.85 times with disease duration more than 4.5 years. The cataract was found in 9.4%. The cut-off point for the development of cataracts was 9.5 years, with a 6.96-fold increased risk. The longer duration of hypoparathyroidism of any etiology was associated with more frequent cataract (p=0.0018).We found brain calcification in 4%, arrhythmias in 7.2% and neuropsychiatric symptoms in 5.15% of cases. Generally, the BMD in the studied group corresponded to age values, and there was no evidence for the phenomenon of high bone density. TBS was consistent with normal bone microarchitectonics. In our study, the majority of patients (83.5%) was treated with standard therapy of calcium and vitamin D supplements. 5 patients with severe disease course were treated with rhPTH (1-34).

CONCLUSIONS

Analysis of the presented database indicates insufficient diagnosis of the complications associated with chronic hypoparathyroidism. Overall, hypoparathyroidism is associated with higher risks of renal stone formation, decreased GFR, cataract especially in patients with longer duration of disease.

Quantitative investigation of the effect of surgically induced hypoparathyroidism on cataract development

INTRODUCTION

Although cataract formation is known in hypoparathyroidism, lens clarity and its correlation with clinical parameters have not been investigated quantitatively before in patients with hypoparathyroidism. The aim of this study was to compare the crystalline lens clarity of patients with surgically induced hypoparathyroidism and healthy subjects.

MATERIALS AND METHODS

Forty female patients with surgically induced hypoparathyroidism and 38 age-matched healthy female subjects were enrolled in this study. Scheimpflug corneal topography was performed to measure lens density (LD) and thickness (LT). Serum calcium, inorganic phosphorus, parathyroid hormone (PTH) levels, and disease duration were recorded.

RESULTS

No statistically significant difference was observed between the hypoparathyroidism and control groups in the Pentacam densitometry zones 1-2-3, LT, and average and maximum LD (p > 0.05 for all). Nine blue-dot-like, two cortical, and two posterior subcapsular cataracts were detected in the hypoparathyroidism group. The frequency of total and blue-dot-like cataracts was significantly higher in the hypoparathyroidism group than in the control group (p = 0.008 and p = 0.002, respectively). In the hypoparathyroidism group, a significant correlation was observed between the maximum LD and the hypoparathyroidism duration (ß = 0.420, p = 0.017), and the maximum LD and serum PTH level (ß = -0.332, p = 0.049).

CONCLUSION

The clarity of the crystalline lens may decrease in surgically induced hypoparathyroidism patients depending on the disease duration and PTH levels. Additionally, this study detected an increased frequency of blue-dot-like cataract in the patient group, which may be due to the effect of hypoparathyroidism.

The PARADIGHM (physicians advancing disease knowledge in hypoparathyroidism) registry for patients with chronic hypoparathyroidism: study protocol and interim baseline patient characteristics

BACKGROUND

The PARADIGHM registry of adult and pediatric patients with chronic hypoparathyroidism evaluates the long-term safety and effectiveness of treatment with recombinant human parathyroid hormone, rhPTH(1-84), and describes the clinical disease course under conditions of routine clinical practice. In this first report, we detail the registry protocol and describe the baseline characteristics of two adult patient cohorts from an interim database analysis. One cohort after study entry were prescribed rhPTH(1-84), and the other cohort received conventional therapy of calcium and active vitamin D.

METHODS

An observational study of patients with chronic hypoparathyroidism in North America and Europe, collecting data for ≥10 years per patient. Main outcome measures were baseline patient demographics, clinical characteristics, medications, and disease outcome variables of symptoms, biochemical parameters, and health assessments. Baseline is the enrollment assessment for all variables except biochemical measurements in patients treated with rhPTH(1-84); those measurements were the most recent value before the first rhPTH(1-84) dose. Exclusion criteria applied to the analysis of specified outcomes included pediatric patients, patients who initiated rhPTH(1-84) prior to enrollment, and those who received rhPTH(1-34). Clinically implausible biochemical outlier data were excluded.

RESULTS

As of 30 June 2019, data of 737 patients were analyzed from 64 centers; 587 (80%) were women, mean ± SD age 49.1±16.45 years. At enrollment, symptoms reported for patients later prescribed rhPTH(1-84) (n=60) and those who received conventional therapy (n=571), respectively, included fatigue (51.7%, 40.1%), paresthesia (51.7%, 29.6%), muscle twitching (48.3%, 21.9%), and muscle cramping (41.7%, 33.8%). Mean serum total calcium, serum phosphate, creatinine, and estimated glomerular filtration rate were similar between cohorts. Health-related quality of life (HRQoL) 36-item Short Form Health Survey questionnaire scores for those later prescribed rhPTH(1-84) were generally lower than those for patients in the conventional therapy cohort.

CONCLUSIONS

At enrollment, based on symptoms and HRQoL, a greater percentage of patients subsequently prescribed rhPTH(1-84) appeared to have an increased burden of disease than those who received conventional therapy despite having normal biochemistry measurements. PARADIGHM will provide valuable real-world insights on the clinical course of hypoparathyroidism in patients treated with rhPTH(1-84) or conventional therapy in routine clinical practice.

TRIAL REGISTRATION

EUPAS16927, NCT01922440.

Fahr's Syndrome Presenting With Hypocalcemia and Psychotic Features

Fahr's disease is a rare genetic neurodegenerative disorder described as “bilateral striopallidodentate calcinosis” (BSPDC). It is characterized by calcium deposition crossing the blood-brain barrier and calcifying different brain areas. Here, we report a case of a 26-year-old Saudi young lady, known as a case of epilepsy since childhood, a major depressive disorder with psychotic features, and hypocalcemia related to hypoparathyroidism. CT brain showed extensive coarse calcifications involving the infra and supratentorial white matter, predominantly within the basal ganglia, thalami, and dentate nuclei of cerebellar hemispheres. This report will discuss the challenging presentation, clinical symptoms, and the multidisciplinary approach to manage Fahr's syndrome symptoms. In conclusion, this case emphasizes the importance of neuroimaging and metabolic workup when investigating the seizure's etiology. The goal of treatment in Fahr's syndrome is to manage the underlying conditions.

[Review of clinical practice guidelines for hypoparathyroidism]

Hypoparathyroidism is a rare disorder characterized by the absent or inappropriately decreased serum parathyroid hormone in the parathyroid glands, which is accompanied by impaired calcium-phosphorus metabolism.The main etiology of hypoparathyroidism remains damage or removal of the parathyroid glands during neck surgery. In view of the incidence of thyroid cancer, primary hyperparathyroidism and other pathologies of the neck organs, which radical treatment can lead to the parathyroid gland impairment, an increased number of patients with hypoparathyroidism is expected. Autoimmune hypoparathyroidism is the second most common form of the disease, usually occurring as part of type 1 autoimmune polyglandular syndrome. Autoimmune hypoparathyroidism usually occurs in childhood and is characterized by a severe course of the disease, especially in the case of concomitant malabsorption syndrome.Chronic hypoparathyroidism of any etiology requires lifelong multicomponent therapy, as well as careful monitoring and an individual approach to choose the optimal treatment strategy. In the absence of adequate follow-up, the risks of long-term complications significantly increase, particularly in the renal, cardiovascular systems; in the soft tissues and in the brain, it could lead to visual disturbances; pathology of the musculoskeletal system with a decreased bone remodeling and a potential risk of fractures, as well as to the neurocognitive disorders and an impaired health-related quality of life.Timely diagnosis, rational medical therapy and management strategy may reduce the risks of short-term and long-term complications, frequency of hospitalizations and disability of patients, as well as improve the prognosis.This review covers the main issues of Russian guidelines for the management of chronic hypoparathyroidism, approved in 2021, including laboratory and instrumental evaluation, treatment approaches and follow-up. This guidelines also include the recommendations for special groups of patients: with acute hypocalcemia, hypoparathyroidism during pregnancy.

Impact of Permanent Post-thyroidectomy Hypoparathyroidism on Self-evaluation of Quality of Life and Voice: Results from the National QoL-hypopara Study

OBJECTIVE

To compare the quality of life (mental health) and voice in patients with or without permanent hypoparathyroidism after total thyroidectomy.

SUMMARY BACKGROUND DATA

Permanent hypoparathyroidism is an underestimated complication of thyroid surgery owing to suppression of parathormone secretion. Few studies have evaluated the consequences of hypoparathyroidism on quality of life and none has studied its effects on voice.

METHODS

The QoL-hypopara study (ClinicalTrial.gov NCT04053647) was a national observational study. Adult thyroidectomized patients were included between January and June 2020. A Serum parathormone level <15pg/mL more than 6 months after surgery defined permanent hypoparathyroidism. Patients answered the MOS-36-item short-form health (SF-36), the Voice Handicap Index (VHI) surveys, and a list of questions regarding their symptoms.

RESULTS

141 patients were included, 45 with permanent hypoparathyroidism. The median period between thyroid surgery and the questionnaire was 6 [Q1-Q3 4-11] and 4 [4-5] years in hypoparathyroid patients and controls respectively. Hypoparathyroid patients presented a reduced median mental score ratio (SF-36) (0.88 [Q1-Q3 0.63-1.01] versus 1.04 [0.82-1.13], P=0.003) and a lower voice quality (incidence rate ratio for total VHI 1.83-fold higher, P<0.001). In multivariable analysis, hypoparathyroidism (-0.17 [95%CI -0.28--0.07], P=0.002), but not age, female sex, thyroid cancer, or abnormal TSH level, was associated with the reduced mental score ratio. Myalgia, joint pain, paresthesia, tetany, anxiety attack and exhaustion were the most common symptoms among hypoparathyroid patients (>50%).

CONCLUSIONS

Hypoparathyroid patients present significantly impaired quality of life, lower voice quality and frequent symptoms. These results reinforce the importance of preventing this complication.

Burden of illness in patients with chronic hypoparathyroidism not adequately controlled with conventional therapy: a Belgium and the Netherlands survey

PURPOSE

To determine the burden of illness in patients with not adequately controlled chronic hypoparathyroidism receiving conventional therapy in Belgium and the Netherlands.

METHODS

Data were generated from a cross-sectional, two-part online survey where endocrinologists from both countries and nephrologists from Belgium were invited by phone to participate. Part 1 included collecting data on general management of patients with hypoparathyroidism. In Part 2, physicians were requested to provide data on one or two current cases of patients with chronic hypoparathyroidism not adequately controlled on conventional therapy. Data collected included aetiology of hypoparathyroidism, clinical manifestations, comorbidities, results of laboratory and other investigations used for diagnosis and screening for complications, therapy received, and physician's perception of impaired quality of life (QoL).

RESULTS

Thirty-six endocrinologists and 29 nephrologists from Belgium and 28 endocrinologists from the Netherlands participated in the survey. Data included clinical symptoms, biochemical parameters, and QoL for 97 current patients with not adequately controlled chronic hypoparathyroidism on conventional therapy. Median duration of not adequately controlled hypoparathyroidism was 2.2 years, range 0.17-20.0. Most patients had neuromuscular (85%) and/or neurological (67%) symptoms, 71% had abnormal biochemical parameters, 10% were overweight, and physicians perceived that 71% had impaired QoL. Most frequently reported comorbidities included hypertension (25%), renal comorbidity (20%), diabetes mellitus (12%), and dyslipidaemia (11%).

CONCLUSION

Patients with chronic hypoparathyroidism not adequately controlled on conventional therapy experience a substantial burden of illness, mainly due to persistence of symptoms and presence of multiple comorbidities.

Safety and Efficacy of Oral Human Parathyroid Hormone (1-34) in Hypoparathyroidism: An Open-Label Study

The standard treatment of primary hypoparathyroidism (hypoPT) with oral calcium supplementation and calcitriol (or an analog), intended to control hypocalcemia and hyperphosphatemia and avoid hypercalciuria, remains challenging for both patients and clinicians. In 2015, human parathyroid hormone (hPTH) (1-84) administered as a daily subcutaneous injection was approved as an adjunctive treatment in patients who cannot be well controlled on the standard treatments alone. This open-label study aimed to assess the safety and efficacy of an oral hPTH(1-34) formulation as an adjunct to standard treatment in adult subjects with hypoparathyroidism. Oral hPTH(1-34) tablets (0.75 mg human hPTH(1-34) acetate) were administered four times daily for 16 consecutive weeks, and changes in calcium supplementation and alfacalcidol use, albumin-adjusted serum calcium (ACa), serum phosphate, urinary calcium excretion, and quality of life throughout the study were monitored. Of the 19 enrolled subjects, 15 completed the trial per protocol. A median 42% reduction from baseline in exogenous calcium dose was recorded (p = .001), whereas median serum ACa levels remained above the lower target ACa levels for hypoPT patients (>7.5 mg/dL) throughout the study. Median serum phosphate levels rapidly decreased (23%, p = .0003) 2 hours after the first dose and were maintained within the normal range for the duration of the study. A notable, but not statistically significant, median decrease (21%, p = .07) in 24-hour urine calcium excretion was observed between the first and last treatment days. Only four possible drug-related, non-serious adverse events were reported over the 16-week study, all by the same patient. A small but statistically significant increase from baseline quality of life (5%, p = .03) was reported by the end of the treatment period. Oral hPTH(1-34) treatment was generally safe and well tolerated and allowed for a reduction in exogenous calcium supplementation, while maintaining normocalcemia in adult patients with hypoparathyroidism. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The association between hypoparathyroidism and cognitive impairment: a systematic review

CONTEXT AND PURPOSE

Hypocalcemia and low parathyroid hormone levels have been commonly suggested as factors able to induce central nervous system disturbances. However, evidences on the occurrence of cognitive impairment are limited or underestimated. The aim of this review is, therefore, to systematically summarize the available evidence concerning the occurrence of cognitive impairment among subjects suffering from idiopathic or secondary hypoparathyroidism.

METHODS

A systematic selection of the available literature was performed by searching the online databases PubMed, Scopus and Web of Knowledge.

RESULTS

The present systematic review included sixteen case report articles and one cross-sectional controlled study. Case reports were the most representative literature sources and involved ten women and seven men. The presence of cognitive impairment was mostly discussed in association with idiopathic hypoparathyroidism (HPT); five articles described the occurrence of cognitive impairment following postsurgical HPT. The case-controlled study reported a significant presence of peculiar cognitive deficits (e.g. reduced inhibitory control, impairment in visuo-spatial functioning among, and psychomotor retardation) among HPT subjects compared to healthy controls, with serum total calcium and its product with phosphorus as independent predictors of neuropsychological dysfunctions.

CONCLUSION

Even though mostly based on single case reports, the presence of neuropsychological dysfunctions in the context of HPT appears to be a consistent core finding.

Canadian national hypoparathyroidism registry: an overview of hypoparathyroidism in Canada

PURPOSE

To evaluate the epidemiology, presentation and management of hypoparathyroidism in Canada. Hypoparathyroidism is associated with significant morbidity and poor quality of life. We present baseline results from the Canadian National Hypoparathyroidism Registry, a prospective observational study evaluating hypoparathyroidism in Canada.

METHODS

Our study enrolled 130 patients with hypoparathyroidism. Patients were followed every 6 months with clinical and lab assessments. We present baseline data in this manuscript.

RESULTS

Seventy percent (91/130) of patients had postsurgical hypoparathyroidism, 30% (39/130) of patients had nonsurgical hypoparathyroidism due to autoimmune, genetic or idiopathic causes, and a molecular diagnosis was confirmed in 11 of these 39 patients. Pseudohypoparathyroidism was confirmed in 4/39 patients, DiGeorge syndrome in 2/39 patients, Barakat syndrome with a mutation in the GATA3 gene in 1/39, and activating mutations of the CASR gene in 3/39 patients with nonsurgical hypoparathyroidism. Renal complications with nephrocalcinosis or nephrolithiasis were present in 27% (14/52) of patients with postsurgical disease and 17% (4/24) of patients with nonsurgical hypoparathyroidism. Basal ganglia calcification was noted on imaging in 15% (n = 5/34) of patients with postsurgical hypoparathyroidism and 37% (n = 7/19) of patients with nonsurgical hypoparathyroidism.

CONCLUSIONS

Hypercalciuria was more commonly seen in those with renal complications of nephrocalcinosis, nephrolithiasis or CKD, and hyperphosphatemia was more commonly seen in those with basal ganglia calcification. Hospitalization occurred in 28% of those with postsurgical hypoparathyroidism and 46% of those with nonsurgical hypoparathyroidism. Hypoparathyroidism is associated with significant morbidity. Effective strategies to reduce the short-and long-term complications of hypoparathyroidism need to be developed and evaluated.

Risk of Nephrolithiasis and Nephrocalcinosis in Patients with Chronic Hypoparathyroidism: A Retrospective Cohort Study

Introduction

Chronic hypoparathyroidism managed with conventional treatment, comprising oral administration of calcium and active vitamin D, has been associated with renal complications, including nephrolithiasis and nephrocalcinosis. Further larger-scale studies are needed to examine these risks. This study evaluated the risk of nephrolithiasis and nephrocalcinosis in patients with chronic hypoparathyroidism.

Methods

A retrospective cohort study using a managed care claims database in the United States from January 2007 to June 2017. Included patients were those with chronic hypoparathyroidism (excluding those receiving parathyroid hormone) and randomly selected patients without hypoparathyroidism over a maximum of 5-year follow-up. The main outcome measures were nephrolithiasis, identified by diagnosis codes or procedure codes for removing kidney stones, and nephrocalcinosis, identified by diagnosis codes.

Results

The nephrolithiasis analyses included 8097 adult patients with hypoparathyroidism and 40,485 adult patients without hypoparathyroidism. After excluding patients with a diagnosis of nephrocalcinosis at baseline, nephrocalcinosis analyses included 8051 patients with hypoparathyroidism and 40,466 patients without hypoparathyroidism. During 5 years of follow-up, patients with chronic hypoparathyroidism had significantly increased risk of nephrolithiasis and nephrocalcinosis in Kaplan–Meier analysis compared with patients without hypoparathyroidism (both P < 0.001). In the adjusted analyses, chronic hypoparathyroidism was associated with higher risks of nephrolithiasis (hazard ratio [HR], 1.81; 95% confidence interval [CI] 1.60–2.04) and nephrocalcinosis (HR, 6.94; 95% CI 4.41–10.92). A sensitivity analysis restricted to patients with at least one kidney imaging examination showed that 2.6% of patients (n = 59) with hypoparathyroidism and 0.5% of patients (n = 20) without hypoparathyroidism (ratio, 5.5; P < 0.001) developed nephrocalcinosis.

Conclusions

This large retrospective cohort study showed a statistically significant and clinically meaningful increased risk of nephrolithiasis and nephrocalcinosis in patients who have chronic hypoparathyroidism compared with those who do not have chronic hypoparathyroidism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01649-2.

Chronic hypoparathyroidism and treatment with teriparatide

PURPOSE

Chronic hypoparathyroidism is usually treated with calcium and active vitamin D metabolites or analogs, despite the fact that their chronic use can lead to long-term complications. The use of hormone replacement therapy with PTH peptides [teriparatide and rhPTH (1-84)] has therefore been proposed. The main purpose of this study was to investigate the efficacy of teriparatide dose at 20 µg once or twice daily, in order to maintain normocalcemia reducing standard treatment, in adult patients with chronic hypoparathyroidism not well controlled with conventional treatment.

METHODS

The study was a Phase III, open-label, non-comparative, clinical investigation (study period: 3 months), at a tertiary care clinical research center. Thirty patients with chronic hypoparathyroidism were screened, and 12 started teriparatide. After the optimization phase (0-4 weeks), calcium and calcitriol supplements were progressively reduced, while teriparatide 20 µg once daily was administered (5-7 weeks), and then could be titrated up to 20 µg twice daily (7-17 weeks). The main outcome measures included serum and urinary biochemical exams and Rand 36-Item Short Form Health Survey.

RESULTS

This study showed that teriparatide 20 µg once daily was insufficient to discontinue calcium and calcitriol supplements to maintain normal serum calcium concentrations. Conversely, for more than half of patients treated with teriparatide 20 µg twice daily, calcium and calcitriol administration was avoidable, but in some cases at the expense of serum calcium and phosphate oscillations.

CONCLUSIONS

Since intervention trials evaluating the efficacy and safety of teriparatide in hypoparathyroid patients are not yet available, the routine use of this molecule poses some doubts.

Hipopara-Red, Real Life Experience in 322 Patients With Hypoparathyroidism

Context

Hypoparathyroidism is a rare disease and, as such, its natural history, long-term complications, and correct clinical management remain unclear.

Objective

To describe the natural history and clinical characteristics of the disease.

Design and Setting

To present a retrospective observational analysis from 7 specialized centers in Buenos Aires, Argentina.

Patients

Chronic hypoparathyroid patients followed-up between 1985 and December 2018.

Main Outcome Measures

Data on demographics, etiology, clinical complications, biochemical parameters, dual-energy x-ray absorptiometry (DXA) values, and treatment doses were collected.

Results

A total of 322 subjects with chronic hypoparathyroidism were included; 85.7% were female, the mean age was 55.2 ± 16.8 years, and the mean age at diagnosis was 43.8 ± 16.8 years. Prevalence of surgical hypoparathyroidism was 90.7%, with the most common causes being thyroid carcinoma and benign thyroid disease. A history of hypocalcemia requiring hospitalization was present in 25.7% of the whole group and in 4.3% of patients who had a history of seizures. Overall, 40.9% of our patients had reported at least 1 neuromuscular symptom. Renal insufficiency was present in 22.4% of our patients and was significantly associated with age (P < 0.0001). Hyperphosphatemia was present in 42% of patients. A history of severe hypocalcemia, paresthesias, tetany, ganglia calcifications, seizures, and cataracts was significantly higher in nonsurgical patients.

Conclusion

Although these patients were followed-up by experienced physicians, clinical management was heterogeneous and probably insufficient to assess all the potential complications of this chronic disease. Almost 70% of the study’s group of patients met the experts’ indications for considering the use of rhPTH 1–84. Being aware of this fact is the 1^st step in improving our medical management of this disease in the future.

Quality of Life in Patients With Hypoparathyroidism After Treatment for Thyroid Cancer

PURPOSE

Surgical complications such as hypoparathyroidism (HPT) or vocal cord palsy are seldom assessed when the quality of life (QOL) in thyroid cancer patients is investigated. The aim of this study was to measure the QOL difference in thyroid cancer survivors with and without HPT.

METHODS

Participants for this analysis were enrolled in 13 countries from a study that pilot-tested a thyroid cancer-specific QOL instrument. They were included if they had been diagnosed with thyroid cancer at least 9 months previously. QOL was measured using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core (EORTC QLQ-C30) and some items on HPT symptoms (eg, tingling in fingers or toes). HPT status and other clinical data were extracted from the patients' medical charts. Comparisons of QOL domains between patients with and without HPT were performed using Mann-Whitney U test. The occurrence of HPT-related symptoms was compared using chi-square tests. Multiple ordinal regression analysis was performed to evaluate factors that might affect QOL.

RESULTS

Eighty-nine patients participated in this study, 17 of whom were considered to have HPT. Patients in the HPT group reported significantly reduced QOL in 9 of the 15 scales of the EORTC QLQ-C30 compared to patients without HPT. Regression analysis showed that HPT was independently negatively associated with various scales of the QLQ-C30. Both groups showed a high prevalence of typical HPT symptoms.

CONCLUSION

Thyroid cancer patients with HPT report significantly impaired QOL compared to thyroid cancer survivors without HPT. The assessment of HPT should be considered when measuring QOL in thyroid cancer patients.

[Evaluation of chronic hypoparathyroidism course according to the Database of Endocrinology Research Centre]

BACKGRAUND

Currently high frequency of thyroid or parathyroid surgery is associated with significant increased incidence of hypoparathyroidism. Evaluation of the epidemiological and clinical features of chronic hypoparathyroidism is necessary to predict social-significant complications and to improve the quality of medical care.

AIMS

To estimate clinical and demographic features, different regimens and efficacy of conventional therapy in patients with chronic postsurgical and nonsurgical hypoparathyroidism.

MATERIALS AND METHODS

The cross-sectional, observational, continuous study was carried out based on Database of patients with chronic postsurgical and nonsurgical hypoparathyroidism of Endocrinology Research Centre, Moscow. 293 patients from 61 regions of the Russian Federation were included in this study. Statistical analysis was done on June 2020. The descriptive statistics are presented by medians (Ме) and the first and third quartiles (Q1; Q3) and by absolute and relative frequencies.

RESULTS

Hypoparathyroidism was most often recorded in women (85%) at the age of 43 [32; 52] years, after thyroid surgery. Less than a half of the study group had target indicators of serum calcium and phosphate levels (31% and 47%, respectively) despite ongoing treatment. A complex instrumental examination for the disease complications was performed in 58% of cases (n = 169). Among them, kidney disorders were detected in 38%, visual disturbance in 14%, brain calcification in 10%, arrhythmias in 4% and neuropsychiatric symptoms in 6%. Conventional therapy with calcium supplements and activated vitamin D analogues was noted in 75% of patients.

CONCLUSIONS

The analysis of large databases of patients with chronic hypoparathyroidism is a necessary tool for determining of optimal clinical and therapeutic approaches, as well as prognostic markers of disease complications.

Five-year Estimated Glomerular Filtration Rate in Patients With Hypoparathyroidism Treated With and Without rhPTH(1-84)

CONTEXT

Chronic hypoparathyroidism (HypoPT) is conventionally managed with oral calcium and active vitamin D. Recombinant human parathyroid hormone (1-84) (rhPTH[1-84]) is a therapy targeting the pathophysiology of HypoPT by replacing parathyroid hormone.

OBJECTIVE

To compare changes in the estimated glomerular filtration rate (eGFR) in patients with chronic HypoPT receiving or not receiving rhPTH(1-84) during a 5-year period.

DESIGN/SETTING

A retrospective analysis of patients with chronic HypoPT treated with or without rhPTH(1-84).

PATIENTS

Sixty-nine patients with chronic HypoPT from 4 open-label, long-term trials (NCT00732615, NCT01268098, NCT01297309, and NCT02910466) composed the rhPTH(1-84) cohort and 53 patients with chronic HypoPT not receiving rhPTH(1-84) from the Geisinger Healthcare Database (01/2004-06/2016) composed the historical control cohort.

INTERVENTIONS

The rhPTH(1-84) cohort (N = 69) received rhPTH(1-84) therapy; the historical control cohort (N = 53) did not receive rhPTH(1-84).

MAIN OUTCOME MEASURES

Changes in eGFR from baseline during a 5-year follow-up were examined in multivariate regression analyses.

RESULTS

At baseline, demographic characteristics and eGFR were similar between cohorts, though the proportions with diabetes and cardiac disorders were lower in the rhPTH(1-84) cohort. At the end of follow-up, mean eGFR increased by 2.8 mL/min/1.73 m2 in the rhPTH(1-84) cohort, while mean eGFR fell by 8.0 mL/min/1.73 m2 in the control cohort. In the adjusted model, the difference in the annual eGFR change between the rhPTH(1-84) cohort and the control cohort was 1.7 mL/min/1.73 m2 per year (P = 0.009).

CONCLUSIONS

Estimated glomerular filtration rate was preserved for over 5 years among patients with chronic HypoPT receiving rhPTH(1-84) treatment, contrasting with an eGFR decline among those not receiving rhPTH(1-84).

Recent advances in understanding and managing hypoparathyroidism

Hypoparathyroidism is a rare endocrine disorder which leads to hypocalcemia, hypercalciuria, and hyperphosphatemia. Complications include nephrocalcinosis with renal dysfunction, reduced quality of life, and abnormal skeletal properties. Conventional therapy with calcium and vitamin D analogs addresses hypocalcemia but has important limitations. Parathyroid hormone (PTH) therapy is a fundamental advance, although the effects of PTH on long-term complications require additional testing. Continuous PTH therapy is likely to be particularly advantageous for addressing renal, quality of life, and skeletal complications. Overall, much progress has been made, yet more information is needed to improve our understanding and management of hypoparathyroidism.