Bone Status Among Patients With Nonsurgical Hypoparathyroidism, Autosomal Dominant Hypocalcaemia, and Pseudohypoparathyroidism: A Cohort Study

Bone Microstructure and Bone Strength Among Patients with Pseudohypoparathyroidism

The present study aimed to assess bone strength and microstructure in patients with pseudohypoparathyroidism (PHP), nonsurgical HP (NS-HP), and healthy controls. A total of 54 PHP1 patients (14 PHP1a, 40 PHP1b), 54 age-/sex- matched NS-HP patients and 27 age-/sex-matched controls were enrolled. Clinical characteristics, biochemical indices and HR-pQCT indices were respectively collected. PHP1 patients had higher serum Ca and PTH level than NS-HP patients at the time of both diagnosis and HR-pQCT measurement. A higher BMI and lower serum P level were observed in PHP1 patients than NS-HP patients at the time of HR-pQCT measurement. Bone microstructure analysis showed PHP1 patients had decreased Tb.N, increased Tb.Sp, and increased Tb.1/N.SD at tibia compared to NS-HP patients. Subgroup analysis showed no significant difference in Tb.N and Tb.Sp in PHP1b patients compared to NS-HP patients. Multiple linear regression analysis showed increased Tb.N and decreased Tb.Sp at tibia were associated with longer treatment duration in PHP1b patients. The microarchitecture evaluated by HR-pQCT in this study further supported that bone tissue had a preserved sensitivity to PTH in PHP1 patients and trabecular bone was more susceptible. Moreover, at least, bone status in PHP1b patients might benefit from regular treatment.

Hypoparathyroidism: Musculoskeletal Manifestations Related to Parathormone Deficiency

BACKGROUND

Hypoparathyroidism is a rare metabolic disorder that can be responsible for musculoskeletal manifestations.

AIM

We present a systematic review of musculoskeletal manifestations of adult-onset nonsurgical nongenetic hypoparathyroidism.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline using the MEDLINE database, including manuscripts describing musculoskeletal manifestations of adult-onset nonsurgical nongenetic hypoparathyroidism.

RESULTS

Musculoskeletal manifestations included myopathy, shoulder disorder, immune-negative non-erosive peripheral arthritis, axial involvement simulating spondylarthritis, and diffuse ligamentous ossifications. An association between hypoparathyroidism and spondyloarthritis or autoimmune diseases is possible. T-cell activation, seen in patients with hypoparathyroidism, may explain the co-occurrence of hypoparathyroidism with other autoimmune diseases. The treatment of these manifestations is based on calcium and active vitamin D supplementation. Parathyroid hormone may have an anabolic effect on muscle atrophy and muscle weakness. Parathyroid hormone can also promote bone formation and bone resorption by stimulating osteoclast differentiation by increasing RANKL (receptor activator for nuclear factor kappa-B ligand) expression. Therefore, hypoparathyroidism can be responsible for an increase in bone mineral density. However, the risk of fractures does not appear to be reduced due to changes in bone microarchitecture and the high risk of falls. Treatment with parathyroid hormone has been shown to improve bone microarchitecture.

CONCLUSION

Our review showed that musculoskeletal manifestations are frequent in patients with hypoparathyroidism, including muscular, axial, peripheral articular, and entheseal manifestations.

C-Cell Hyperplasia and Cystic Papillary Thyroid Carcinoma in a Patient with Type 1B Pseudohypoparathyroidism and Hypercalcitoninaemia: Case Report and Review of the Literature

Hypercalcitoninaemia has been described in patients with pseudohypoparathyroidism (PHP) type 1A and 1B. Elevated calcitonin levels are thought to result from impaired Gsα receptor signaling, leading to multiple hormone resistance. Evidence on the risk of medullary thyroid carcinoma (MTC) or C-cell hyperplasia in PHP patients with hypercalcitoninaemia is lacking. A 43-year-old Caucasian man was referred to our endocrinology clinic for chronic hypocalcemia associated with elevated serum parathormone levels and a single cystic thyroid nodule. The patient did not show skeletal deformities, and screening for concomitant hormone resistances was negative, except for the presence of elevated serum calcitonin levels. The workup led to a molecular diagnosis of sporadic PHP1B. Fine needle aspiration of the thyroid nodule was not diagnostic. The calcium stimulation test yielded an abnormal calcitonin response. Given the scarcity of data on the risk of thyroid malignancy in PHP and calcium stimulation test results, total thyroidectomy was performed. Histological examination revealed cystic papillary thyroid cancer in a background of diffuse C-cell hyperplasia. To our knowledge, we are the first to describe a rare form of thyroid cancer combined with C-cell hyperplasia in a patient with PHP and hypercalcitoninaemia. In the present case, a mere receptor resistance might not fully explain the elevated calcitonin levels, suggesting that hypercalcitoninaemia should be carefully evaluated in PHP patients, especially in the case of concomitant thyroid nodules. Further studies on larger cohorts are needed to elucidate this topic.

Bone turnover markers are associated with the PTH levels in different subtypes of pseudohypoparathyroidism type 1 patients

OBJECTIVE

Bone responsiveness to parathyroid hormone (PTH) in different subtypes of pseudohypoparathyroidism type 1 (PHP1) remains controversial. We aimed to investigate this phenomenon using bone turnover markers (BTMs) in a large cohort of PHP1 patients.

DESIGN

Retrospective study.

PATIENTS

Sixty-three PHP1 patients diagnosed by molecular analysis were used as subjects, and 48 sex- and age-matched patients with nonsurgical hypoparathyroidism (NS-HP) were used for comparison.

MEASUREMENTS

Bone turnover markers, alkaline phosphatase (ALP), C-terminal telopeptide of type I collagen (β-CTX) and related parameters in PHP1 were compared among different subtypes and with NS-HP.

RESULTS

Among all the PHP1 patients (15 PHP1A, 14 familial 1B and 34 sporadic 1B), 23.8% had elevated baseline BTM levels. No significant difference was found in the β-CTX levels among different subtypes. The β-CTX level was positively correlated with the PTH level for all PHP1, PHP1B and PHP1A patients (B = 0.001, 0.001 and 0.004, respectively; all p < .05). The BTM levels of PHP1 patients were significantly higher than those of NS-HP patients (β-CTX: 0.56 ng/ml vs. 0.20 ng/ml, p = .001; ALP: 105 U/L vs. 72 U/L, p = .001). The serum β-CTX levels in different PHP1 subtypes were all significantly higher than those in NS-HP patients in adults. Among the 22 followed up patients, changes in BTMs were associated with changes in PTH (β-CTX: r = .507, p = .023; ALP: r = .475, p = .034).

CONCLUSIONS

Bone tissues respond to PTH in different PHP1 subtypes, and it is reasonable to monitor and normalize PTH and BTMs in addition to the serum and urinary calcium levels in the follow-up of PHP1 patients.

Lower Leg Arterial Calcifications Assessed by High-Resolution Peripheral Quantitative Computed Tomography in Hypoparathyroid and Pseudohypoparathyroid Patients

Hypoparathyroidism (HypoPT) and pseudohypoparathyroidism (PHP) are diseases with abnormal calcium and phosphate homeostasis and low and high PTH levels, respectively. It has been hypothesized that this could dispose to vascular calcifications and thereby perhaps also cardiovascular morbidity. The aim of this study was to assess lower leg arterial calcifications (LLAC) in patients with HypoPT or PHP. Using a cross-sectional design, we measured the LLAC using a high-resolution peripheral quantitative computed tomography (HR-pQCT) scanner in 72 patients with HypoPT and 25 patients with PHP and compared them with findings in 61 controls. LLAC were found in only two (3%) of the controls. Compared to the controls, LLAC were significantly more prevalent in patients with HypoPT (N = 12, [17%], p < 0.01) and PHP (N = 4, [16%], p < 0.04). Compared to the patients without calcifications, patients with calcifications had higher plasma calcium levels and a lower eGFR, as well as they were older and more often males. Plasma phosphate levels and the calcium-phosphate product were not associated with LLAC. In conclusion, we found that HypoPT and PHP are associated with an increased prevalence of vascular calcifications.

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.

Parathyroid hormone

Parathyroid hormone is an essential regulator of extracellular calcium and phosphate. PTH enhances calcium reabsorption while inhibiting phosphate reabsorption in the kidneys, increases the synthesis of 1,25-dihydroxyvitamin D, which then increases gastrointestinal absorption of calcium, and increases bone resorption to increase calcium and phosphate. Parathyroid disease can be an isolated endocrine disorder or part of a complex syndrome. Genetic mutations can account for diseases of parathyroid gland formulation, dysregulation of parathyroid hormone synthesis or secretion, and destruction of the parathyroid glands. Over the years, a number of different options are available for the treatment of different types of parathyroid disease. Therapeutic options include surgical removal of hypersecreting parathyroid tissue, administration of parathyroid hormone, vitamin D, activated vitamin D, calcium, phosphate binders, calcium-sensing receptor, and vitamin D receptor activators to name a few. The accurate assessment of parathyroid hormone also provides essential biochemical information to properly diagnose parathyroid disease. Currently available immunoassays may overestimate or underestimate bioactive parathyroid hormone because of interferences from truncated parathyroid hormone fragments, phosphorylation of parathyroid hormone, and oxidation of amino acids of parathyroid hormone.

A paternally inherited non-sense variant c.424G>T (p.G142*) in the first exon of XLαs in an adult patient with hypophosphatemia and osteopetrosis

XLαs, the extra-large isoform of alpha-subunit of the stimulatory guanine nucleotide-binding protein (Gsα), is paternally expressed. The significance of XLαs in humans remains largely unknown. Here, we report a patient who presented with increased bone mass, hypophosphatemia, and elevated parathyroid hormone (PTH) levels. His serum calcium was in the lower limit of the normal range. Whole exome sequencing of this subject found a novel non-sense variant c.424G>T (p. G142*) in the first exon of XLαs, which was inherited from his father and transmitted to his daughter. This variant was predicted to exclusively influence the expression of XLαs, while possibly having no significant effects on other gene products of this locus. Ellsworth-Howard test revealed normal renal response to PTH in proband. Human SaOS2 cells transfected with mutant XLαs failed to generate cyclic adenosine monophosphate under PTH stimulation, indicating skeletal resistance to this hormone. This subject showed higher circulating sclerostin, dickkopf1, and osteoprotegerin (OPG) levels, while lower receptor activator of nuclear factor kappa-B ligand/OPG ratio, leading to reduced bone resorption. Our findings indicate that XLαs plays a critical role in bone metabolism and GNAS locus should be considered as a candidate gene for high bone mass.

Recommendations for Diagnosis and Treatment of Pseudohypoparathyroidism and Related Disorders: An Updated Practical Tool for Physicians and Patients

Patients affected by pseudohypoparathyroidism (PHP) or related disorders are characterized by physical findings that may include brachydactyly, a short stature, a stocky build, early-onset obesity, ectopic ossifications, and neurodevelopmental deficits, as well as hormonal resistance most prominently to parathyroid hormone (PTH). In addition to these alterations, patients may develop other hormonal resistances, leading to overt or subclinical hypothyroidism, hypogonadism and growth hormone (GH) deficiency, impaired growth without measurable evidence for hormonal abnormalities, type 2 diabetes, and skeletal issues with potentially severe limitation of mobility. PHP and related disorders are primarily clinical diagnoses. Given the variability of the clinical, radiological, and biochemical presentation, establishment of the molecular diagnosis is of critical importance for patients. It facilitates management, including prevention of complications, screening and treatment of endocrine deficits, supportive measures, and appropriate genetic counselling. Based on the first international consensus statement for these disorders, this article provides an updated and ready-to-use tool to help physicians and patients outlining relevant interventions and their timing. A life-long coordinated and multidisciplinary approach is recommended, starting as far as possible in early infancy and continuing throughout adulthood with an appropriate and timely transition from pediatric to adult care.

Dental anomalies and orthodontic characteristics in patients with pseudohypoparathyroidism

Background

Pseudohypoparathyroidism (PHP) is a rare and inherited disease caused by mutations in the GNAS-gene or upstream of the GNAS complex locus. It is characterized by end-organ resistance to PTH, resulting in hypocalcemia and hyperphosphatemia. We aimed to investigate the dental anomalies according to tooth types and the orthodontic characteristics of patients with PHP.

Methods

Using a cross-sectional design, 29 patients (23 females) with PHP, living in Denmark, were included, and their clinical intraoral photos and radiographs were examined.

Results

Pulp calcification was found in 76% of the patients. Blunting of root apex was present in 55% and shortening of root in 48% of the examined patients. Blunting and shortening of roots were seen more often in premolars than in other tooth types (p_both < 0.01). Crowding of lower anterior teeth was frequently observed (36%) as well as diastema in the upper arch (25%), midline diastema (18%), and Class III malocclusion (11%).

Conclusion

In the present study population, the teeth were frequently affected by pulp calcification and/or deviation of the root morphology. Blunting and shortening of root(s) were more often seen in premolars than in other tooth types. Class III malocclusion was relatively prevalent. It is important to pay attention to dental anomalies and occlusion in order to provide adequate care for patients with PHP.

Cardiovascular findings in patients with nonsurgical hypoparathyroidism and pseudohypoparathyroidism: A cohort study

OBJECTIVE

As only sparse data are available on indices of cardiovascular health among patients with nonsurgical hypoparathyroidism (Ns-HypoPT) and pseudohypoparathyroidism (PHP), we aimed to compare the cardiovascular profile between these groups of patients.

METHODS

A total of 56 patients with Ns-HypoPT and 30 with PHP were included and underwent a clinical examination including blood sampling and measurements of arterial stiffness, pulse wave velocity (PWV) and blood pressure (BP). Arterial stiffness and PWV were measured using AtCor SphygmoCor-XCEL (Atcor Medical Pty Ltd, Sydney, NSW, Australia).

RESULTS

Patients with Ns-HypoPT had an average age of 47 ± 17 years (68% females) and PHP patients 36 ± 13 years (80% females). Over 70% in both groups were genetically screened. Groups did not differ in terms of a history of cardiovascular disease, smoking status, use of calcium and vitamin D supplements or treatment with cholesterol-lowering or antihypertensive drugs. Compared with Ns-HypoPT, PHP patients had significantly lower levels of high-density lipoproteins (HDL) cholesterol and average glucose from HbA1c (P_both  = 0.01). PWV was significantly higher among patients with Ns-HypoPT (P_crude  = 0.02), even after adjustment for mean arterial pressure, body mass index, age and gender (P_adjusted  < 0.01). Heart rate was significantly higher in Ns-HypoPT compared with PHP (P = 0.03). Office BP and 24-hour ambulatory BP did not differ between groups (P > 0.05).

CONCLUSION

Patients with Ns-HypoPT have compared with PHP a higher arterial stiffness and heart rate. This has been associated with an increased risk of cardiovascular disease. Our data suggest that resistance to PTH is present in the cardiovascular system in PHP.

Hypocalcemic disorders

Calcium is vital for life, and extracellular calcium concentrations must constantly be maintained within a precise concentration range. Low serum calcium (hypocalcemia) occurs in conjunction with multiple disorders and can be life-threatening if severe. Symptoms of acute hypocalcemia include neuromuscular irritability, tetany, and seizures, which are rapidly resolved with intravenous administration of calcium gluconate. However, disorders that lead to chronic hypocalcemia often have more subtle manifestations. Hypoparathyroidism, characterized by impaired secretion of parathyroid hormone (PTH), a key regulatory hormone for maintaining calcium homeostasis, is a classic cause of chronic hypocalcemia. Disorders that disrupt the metabolism of vitamin D can also lead to chronic hypocalcemia, as vitamin D is responsible for increasing the gut absorption of dietary calcium. Treatment and management options for chronic hypocalcemia vary depending on the underlying disorder. For example, in patients with hypoparathyroidism, calcium and vitamin D supplementation must be carefully titrated to avoid symptoms of hypocalcemia while keeping serum calcium in the low-normal range to minimize hypercalciuria, which can lead to renal dysfunction. Management of chronic hypocalcemia requires knowledge of the factors that influence the complex regulatory axes of calcium homeostasis in a given disorder. This chapter discusses common and rare disorders of hypocalcemia, symptoms and workup, and management options including replacement of PTH in hypoparathyroidism.

Health-related quality of life in patients with nonsurgical hypoparathyroidism and pseudohypoparathyroidism

OBJECTIVE

Nonsurgical hypoparathyroidism (NS-HypoPT) and pseudohypoparathyroidism (PHP) are rare diseases, with a prevalence of 2/100.000 and 1/100.000, respectively. Only few studies on Quality of Life (QoL) among patients with Ns-HypoPT and PHP are available. We aimed to investigate the QoL among patients with Ns-HypoPT and PHP including information about education.

DESIGN

A cohort study with patients identified from a previously epidemiological study.

PATIENTS

Fifty seven patients with Ns-HypoPT and 30 patients with PHP.

MEASUREMENTS

The well-validated questionnaires SF-36v2 and WHO-5 Well Being Index. Results compared to norm-based material, disease-specific norm-based material and patients with postsurgical HypoPT RESULTS: SF36v2 showed a significantly reduced score in all eight subdomains in patients with NS-HypoPT compared with a norm-based population. PHP patients scored lower in five subdomains. Females were more affected than males. Compared with postsurgical HypoPT, Ns-HypoPT and PHP are compatible at most domains. At the domains Physical Function, Social Function and Mental Health, Ns-HypoPT and PHP patients scored significantly lower (P_all  < .05). At the Mental Component Score, patients with Ns-HypoPT had a lower score compared with postsurgical HypoPT (P < .01). The overall WHO-5 Well Being Index score was comparable between groups (P = .45). No differences were seen comparing patients with postsurgical HypoPT and Ns-HypoPT (P = .68) or postsurgical HypoPT and PHP (P = .67). A WHO-5 score below 28 indicates depression (NS-HypoPT=7; PHP=3, P = .71), whereas a score between 28-50 suggesting poor emotional well-being (NS-HypoPT=19; PHP=5, P = .13). The remaining patients scored above 50 suggesting well-being.

CONCLUSION

QoL is impaired equally among patients with Ns-HypoPT and PHP.