Renal complications and quality of life in postsurgical hypoparathyroidism: a case-control study

PURPOSE

Conventional therapy (calcium and activated vitamin D) does not restore calcium homeostasis in patients with chronic hypoparathyroidism (HypoPT) and is associated with renal complications and reduced quality of life (QoL). The aim of this study was to evaluate in a case-control, cross-sectional study, the rate of renal complications and QoL in two sex- and age-matched cohort of patients with differentiated thyroid cancer with (n = 89) and without (n = 89) chronic post-operative HypoPT (PoHypoPT) and their relationship with the biochemical control of the disease.

METHODS

Serum and urinary parameters, renal ultrasound and QoL were assessed by SF-36 and WHO-5 questionnaires.

RESULTS

Forty-three (48.3%) PoHypoPT patients reported symptoms of hypocalcemia. Twenty-six (29.2%) patients were at target for all 6 parameters, 46 (51.6%) for 5. The most frequently unmet targets were gender-specific 24-h urinary calcium (44.9%) and serum calcium (37.1%). Serum phosphate, magnesium and 25(OH)D were in the normal range in > 90% of patients. Renal calcifications were found in 26 (29.2%) patients, with no correlation with 24-h urinary calcium. eGFR did not differ between patients and controls. Conversely, patients had a significant higher rate of renal calcifications and a lower SF-36, but not WHO-5, scores. SF-36 scores did not differ between PoHypoPT patients who were, or not, hypocalcemic.

CONCLUSIONS

Our study shows that the rate of renal calcifications was higher in patients with PoHypoPT than in those without. This finding, together with the reduced QoL and the presence of hypocalcemic symptoms in about half patients, underscores that the treatment of chronic HypoPT with conventional therapy is suboptimal.

Novel Glial Cells Missing-2 (GCM2) variants in parathyroid disorders

OBJECTIVE

The aim of this study was to analyze variants of the gene glial cells missing-2 (GCM2), encoding a parathyroid cell-specific transcription factor, in familial hypoparathyroidism and in familial isolated hyperparathyroidism (FIHP) without and with parathyroid carcinoma.

DESIGN

We characterized 2 families with hypoparathyroidism and 19 with FIHP in which we examined the mechanism of action of GCM2 variants.

METHODS

Leukocyte DNA of hypoparathyroid individuals was Sanger sequenced for CASR, PTH, GNA11 and GCM2 mutations. DNA of hyperparathyroid individuals underwent MEN1, CDKN1B, CDC73, CASR, RET and GCM2 sequencing. The actions of identified GCM2 variants were evaluated by in vitro functional analyses.

RESULTS

A novel homozygous p.R67C GCM2 mutation which failed to stimulate transcriptional activity in a luciferase assay was identified in affected members of two hypoparathyroid families. Oligonucleotide pull-down assay and in silico structural modeling indicated that this mutant had lost the ability to bind the consensus GCM recognition sequence of DNA. Two novel (p.I383M and p.T386S) and one previously reported (p.Y394S) heterozygous GCM2 variants that lie within a C-terminal conserved inhibitory domain were identified in three affected individuals of the hyperparathyroid families. One family member, heterozygous for p.I138M, had parathyroid carcinoma (PC), and a heterozygous p.V382M variant was found in another patient affected by sporadic PC. These variants exerted significantly enhanced in vitrotranscriptional activity, including increased stimulation of the PTH promoter.

CONCLUSIONS

We provide evidence that two novel GCM2 R67C inactivating mutations with an inability to bind DNA are causative of hypoparathyroidism. Additionally, we provide evidence that two novel GCM2 variants increased transactivation of the PTH promoter in vitro and are associated with FIHP. Furthermore, our studies suggest that activating GCM2 variants may contribute to facilitating more aggressive parathyroid disease.

Novel Glial Cells Missing-2 (GCM2) variants in parathyroid disorders

OBJECTIVE

The aim of this study was to analyze variants of the gene glial cells missing-2 (GCM2), encoding a parathyroid cell-specific transcription factor, in familial hypoparathyroidism and in familial isolated hyperparathyroidism (FIHP) without and with parathyroid carcinoma.

DESIGN

We characterized 2 families with hypoparathyroidism and 19 with FIHP in which we examined the mechanism of action of GCM2 variants.

METHODS

Leukocyte DNA of hypoparathyroid individuals was Sanger sequenced for CASR, PTH, GNA11 and GCM2 mutations. DNA of hyperparathyroid individuals underwent MEN1, CDKN1B, CDC73, CASR, RET and GCM2 sequencing. The actions of identified GCM2 variants were evaluated by in vitro functional analyses.

RESULTS

A novel homozygous p.R67C GCM2 mutation which failed to stimulate transcriptional activity in a luciferase assay was identified in affected members of two hypoparathyroid families. Oligonucleotide pull-down assay and in silico structural modeling indicated that this mutant had lost the ability to bind the consensus GCM recognition sequence of DNA. Two novel (p.I383M and p.T386S) and one previously reported (p.Y394S) heterozygous GCM2 variants that lie within a C-terminal conserved inhibitory domain were identified in three affected individuals of the hyperparathyroid families. One family member, heterozygous for p.I138M, had parathyroid carcinoma (PC), and a heterozygous p.V382M variant was found in another patient affected by sporadic PC. These variants exerted significantly enhanced in vitrotranscriptional activity, including increased stimulation of the PTH promoter.

CONCLUSIONS

We provide evidence that two novel GCM2 R67C inactivating mutations with an inability to bind DNA are causative of hypoparathyroidism. Additionally, we provide evidence that two novel GCM2 variants increased transactivation of the PTH promoter in vitro and are associated with FIHP. Furthermore, our studies suggest that activating GCM2 variants may contribute to facilitating more aggressive parathyroid disease.

PaTH Forward: A Randomized, Double-Blind, Placebo-Controlled Phase 2 Trial of TransCon PTH in Adult Hypoparathyroidism

CONTEXT

Hypoparathyroidism is characterized by insufficient levels of parathyroid hormone (PTH). TransCon PTH is an investigational long-acting prodrug of PTH(1-34) for the treatment of hypoparathyroidism.

OBJECTIVE

This work aimed to investigate the safety, tolerability, and efficacy of daily TransCon PTH in adults with hypoparathyroidism.

METHODS

This phase 2, randomized, double-blind, placebo-controlled 4-week trial with open-label extension enrolled 59 individuals with hypoparathyroidism. Interventions included TransCon PTH 15, 18, or 21 µg PTH(1-34)/day or placebo for 4 weeks, followed by a 22-week extension during which TransCon PTH dose was titrated (6-60 µg PTH[1-34]/day).

RESULTS

By Week 26, 91% of participants treated with TransCon PTH achieved independence from standard of care (SoC, defined as active vitamin D = 0 μg/day and calcium [Ca] ≤ 500 mg/day). Mean 24-hour urine Ca (uCa) decreased from a baseline mean of 415 mg/24h to 178 mg/24h by Week 26 (n = 44) while normal serum Ca (sCa) was maintained and serum phosphate and serum calcium-phosphate product fell within the normal range. By Week 26, mean scores on the generic 36-Item Short Form Health Survey domains increased from below normal at baseline to within the normal range. The Hypoparathyroidism Patient Experience Scale symptom and impact scores improved through 26 weeks. TransCon PTH was well tolerated with no treatment-related serious or severe adverse events.

CONCLUSION

TransCon PTH enabled independence from oral active vitamin D and reduced Ca supplements (≤ 500 mg/day) for most participants, achieving normal sCa, serum phosphate, uCa, serum calcium-phosphate product, and demonstrating improved health-related quality of life. These results support TransCon PTH as a potential hormone replacement therapy for adults with hypoparathyroidism.

Changes in Serum Calcium and Treatment of Hypoparathyroidism During Pregnancy and Lactation: A Single-center Case Series

BACKGROUND

Hypoparathyroidism (hypo-PT) is rare, and studies on hypo-PT, especially during pregnancy and lactation, are limited.

DESIGN AND SETTING

This was a retrospective study on a relatively large case series in a single center from mainland China.

METHODS

A total of 19 patients with 25 pregnancies, diagnosed with hypo-PT before pregnancy, were enrolled. Data on clinical characteristics and treatment strategies at onset time and around pregnancy period were collected.

RESULTS

During pregnancy, except for 2 patients with missing data, 5 patients with 6 pregnancies (6/23, 26.1%) experienced improved hypo-PT condition, defined as an increased serum calcium level; 4 patients with 4 pregnancies (4/23, 17.4%) experienced worsened hypo-PT condition, defined as a more than 0.2 mmol/L decline in the serum calcium level; and 3 patients with 3 pregnancies (3/23, 13.0%) remained in stable hypo-PT condition. The prevalence of adverse pregnancy outcomes was 30.4% (4/23 for preterm delivery; 3/23 for miscarriage). The serum calcium and 24-hour urine calcium levels significantly increased during lactation compared with pregnancy (2.57 ± 0.34 vs 1.99 ± 0.11 mmol/L, P < 0.001; 12.28 ± 5.41 vs 8.63 ± 3.22 mmol/L, P = 0.013), and 5 patients with 5 lactations (5/12, 41.7%) developed hypercalcemia in the first 2 months after delivery.

CONCLUSIONS

Female patients with hypo-PT had different changes in calcium homeostasis and a high prevalence of adverse outcomes during pregnancy. Thus, they should be monitored closely to maintain the optimal serum calcium level. Decreasing drug dosage during the lactation period should be considered to avoid hypercalcemia.

A prospective study of Salvia miltiorrhiza and Rhizoma chuanxiong preparation in the treatment of hypoparathyroidism after total thyroidectomy

This study aimed to investigate the clinical efficacy of Salvia miltiorrhiza and Rhizoma chuanxiong preparation on hypoparathyroidism. A total of 100 patients with hypoparathyroidism after total thyroidectomy were erolled, they were divided into the observation group (n=50), Salvia miltiorrhiza and Rhizoma chuanxiong preparation were added on the basis of traditional treatment. The control group (n=50), were treated with traditional treatment. To analyze the therapeutic effect of Salvia miltiorrhiza and Rhizoma chuanxiong preparation on hypoparathyroidism. After follow-up, the recovery time of parathyroid function in the observation group was significantly shorter than the control (P<0.05). No permanent hypoparathyroidism in the observation group and 4 cases in the control, which was statistically significant (P<0.05). The serum PTH in the observation group was significantly higher than the control on the 7th, 30th day, 3rd and 6th month. The level of serum calcium in the observation group was significantly higher than the control on the 3rd, 7th and 30th day (P<0.05). Salvia miltiorrhiza and Rhizoma chuanxiong preparation has obvious effects on the treatment of hypoparathyroidism and has low adverse reactions, which is worthy of clinical application.

Near-Infrared Autofluorescence Imaging May Reduce Temporary Hypoparathyroidism in Patients Undergoing Total Thyroidectomy and Central Neck Dissection

Background: Near-infrared autofluorescence (NIRAF) imaging is known to reduce the incidence of post-thyroidectomy hypocalcemia. However, there are no studies on how much NIRAF imaging affects the serum parathyroid hormone (PTH) level after surgery. We investigated the changes of the serum PTH level and ionized calcium (iCa.) in patients undergoing total thyroidectomy with central neck dissection (CND). Materials and Methods: This retrospective study with historical control enrolled 542 patients who underwent total thyroidectomy with CND. Patients were divided into two groups: the NIRAF group (261 patients) and the control group (281 patients). PTH and iCa. levels were measured at the hospital stay, 1, 3, and 6 months after surgery. In addition, the number of identified parathyroid glands (PGs), autotransplanted PGs, and the inadvertent resection rate of PGs was evaluated. Results: The incidence of postoperative hypoparathyroidism (PTH <15 pg/mL) was significantly lower in the NIRAF group during the hospitalization (88 patients: 33.7% vs. 131 patients: 46.6%; p = 0.002) and at 1 month postoperatively (23 patients: 8.8% vs. 53 patients: 18.9%; p = 0.001). There was no difference in the permanent hypoparathyroidism rate (6 months after surgery) between the NIRAF group and the control group (4.2% vs. 4.6%; p = 0.816). There was no difference in the incidence of hypocalcemia (iCa. <1.09 mmol/L) (during hospitalization: 6.5% vs. 10.0%; 1 month: 2.3% vs. 2.5%; 3 months: 0.8% vs. 0.7%; 6 months after surgery: 1.1% vs. 1.1%) between the two groups. The number of inadvertently resected PGs was significantly lower in the NIRAF group (18:6.9% vs. 36:12.8%; p = 0.021). Conclusions: These results suggest that NIRAF imaging may reduce temporary hypoparathyroidism and the risk of inadvertent resection of PGs in patients undergoing total thyroidectomy with CND.

Identification of p.Arg205Cys in CASR in an autosomal dominant hypocalcaemia type 1 pedigree: A case report

RATIONALE

Autosomal dominant hypocalcaemia type 1 (ADH1) is a genetic disease characterized by benign hypocalcemia, inappropriately low parathyroid hormone levels and mostly hypercalciuria. It is caused by the activating mutations of the calcium-sensing receptor gene (CASR), which produces a left-shift in the set point for extracellular calcium.

PATIENT CONCERNS

A 50-year-old man presenting with muscle spasms was admitted into the hospital. He has a positive familial history for hypocalcemia. Auxiliary examinations demonstrated hypocalcemia, hyperphosphatemia, normal parathyroid hormone level and nephrolithiasis. A missense heterozygous variant in CASR, c 613C > T (p. Arg205Cys) which has been reported in a familial hypocalciuric hypercalcemia type 1 patient was found in the patient's genotype. It is the first time that this variant is found associating with ADH1. The variant is predicted vicious by softwares and cosegregates with ADH1 in this pedigree. CASR Arg205Cys was deduced to be the genetic cause of ADH1 in the family.

DIAGNOSIS

The patient was diagnosed with ADH1 clinically and genetically.

INTERVENTIONS

Oral calcitriol, calcium and hydrochlorothiazide were prescribed to the patient.

OUTCOMES

After the treatments for 1 week, the patient's symptom was improved and the re-examination revealed serum calcium in the normal range. A 3-month follow-up showed his symptom was mostly relieved.

LESSONS

The variant of CASR Arg205Cys, responsible for ADH1 in this family, broadened the genetic spectrum of ADH1. Further and more studies are required to evaluate the correlation between genotype and phenotype in ADH1 patients.

Basal Ganglia Calcification Is Associated With Local and Systemic Metabolic Mechanisms in Adult Hypoparathyroidism

CONTEXT

Hypoparathyroidism is characterized by low serum calcium, increased serum phosphorus, and inappropriately low or decreased serum parathyroid hormone, which may be associated with soft tissue calcification in the basal ganglia of the brain.

OBJECTIVE

To assess the prevalence and factors involved in the pathophysiology of basal ganglia calcification (BGC) in the brain in chronic hypoparathyroidism and to evaluate proposed pathophysiologic mechanisms.

DESIGN

Case-control study with retrospective review of medical records over 20 years.

SETTING

Single academic medical center.

PATIENTS

142 patients with chronic hypoparathyroidism and computed tomography (CT) head scans followed between January 1, 2000 and July 9, 2020, and 426 age- and sex-matched controls with CT head scans over the same interval.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Demographic, biochemical, and CT head imaging findings, with semiquantitative assessment of volumetric BGC.

RESULTS

The study found that 25.4% of 142 patients followed for a median of 17 years after diagnosis of chronic hypoparathyroidism had BGC, which developed at a younger age than in controls. BGC was 5.1-fold more common in nonsurgical patients and less common in postsurgical patients. Low serum calcium and low calcium/phosphate ratio correlated with BGC. Neither serum phosphorus nor calcium × phosphate product predicted BGC. Lower serum calcium was associated with greater volume of BGC. The extent of BGC varied widely, with nonsurgical patients generally having a greater volume and distribution of calcification.

CONCLUSIONS

BGC is associated with low serum calcium and low serum calcium/phosphate ratio, which may be related to severity of the disease, its etiology, or duration of treatment.

Alfacalcidol vs Calcitriol in the Management of Patient With Hypoparathyroidism: A Randomized Controlled Trial

CONTEXT

Alfacalcidol and calcitriol are commonly used for managing hypoparathyroidism. Their relative merits have not been systematically assessed.

OBJECTIVE

We compared the effect of alfacalcidol and calcitriol on phosphatemic control, hypercalciuria, and associated factors in idiopathic-hypoparathyroidism (IH).

DESIGN AND SETTING

Open-label randomized controlled trial, tertiary care center.

SUBJECTS AND METHODS

IH patients with optimal calcemic control on alfacalcidol were continued on the same (n = 20) or switched to calcitriol (n = 25) at half of the ongoing alfacalcidol dose. The dose was adjusted during follow-up to maintain serum total calcium between 8.0 and 9.5 mg/dL. Serum calcium, phosphorus, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, 24-h urine calcium-to-creatinine ratio, and fractional excretion of phosphorus (FEPh) were measured at baseline and 6 months. Plasma intact-FGF23 was measured at final follow-up.

RESULT

Patients receiving alfacalcidol and calcitriol had comparable serum calcium at 6 months (8.7 ± 0.4 vs 8.9 ± 0.4 mg/dL, P = 0.13). Their median [interquartile range (IQR)] dose at 6 months was 2.0 (1.0-2.5) and 0.75 (0.5-1.0) µg/d, respectively. Serum 1,25(OH)2D levels were physiological in both (35.3 ± 11.6 and 32.3 ± 16.9 pg/mL). Serum phosphate and calcium excretion were comparable in 2 arms. A majority had hyperphosphatemia (75% vs 76%), hypercalciuria (75% vs 72%), and elevated FGF23 (116 ± 68 and 113 ± 57 pg/mL). Age showed significant independent association with plasma FGF23 (β = 1.9, P = 0.001). Average FEPh was low despite high FGF23.

CONCLUSION

At optimal calcium control, both alfacalcidol and calcitriol lead to comparable but high serum phosphate levels, hypercalciuria, physiological circulating 1,25(OH)2D, and elevated FGF23. Further studies are required to systematically investigate other treatment options.

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.

Impaired Immune Function in Patients With Chronic Postsurgical Hypoparathyroidism: Results of the EMPATHY Study

CONTEXT

Despite the pivotal role of calcium signaling in immune response, little is known about immune function in patients affected by hypoparathyroidism.

OBJECTIVE

This work aimed to evaluate immune function in hypoparathyroidism.

METHODS

The Evaluation of iMmune function in Postsurgical and AuToimmune HYpoparathyroidism (NCT04059380) is a case-control, cross-sectional study set in an Italian referral center. Participants included 20 patients with postsurgical hypoparathyroidism (12 females) and 20 age- and sex-matched controls. Main outcome measures included calcium metabolism assessment, peripheral blood mononuclear cells (PBMC) profiling via flow cytometry, parathyroid hormone receptor 1 (PTHr1) expression analysis using immunofluorescence and PrimeFlow RNA assay, gene expression analysis via real-time polymerase chain reaction, cytokine measurement, and evaluation of infectious disease frequency and severity.

RESULTS

Immune cell profiling revealed decreased monocytes, regulatory, naive, and total CD4+ T lymphocytes, which correlated with total calcium, ionized calcium, and PTH levels, in patients with hypoparathyroidism. Patients with hypoparathyroidism had a higher CD3-CD56+ natural killer (NK) cell count, which inversely correlated with calcium, PTH, and vitamin D levels. Furthermore, they exhibited decreased tumor necrosis factor (TNF) and granulocyte-macrophage colony-stimulating factor gene expression and decreased circulating TNF levels. Gene expression and immunofluorescence analysis confirmed PTHr1 expression in all PBMC lineages; however, the percentage of cells expressing PTHr1 was lower, whereas the intensity of PTHr1 expression in monocytes, total T lymphocytes, CD8+CD4+ and CD4+ T lymphocytes, and total NK cells was higher in patients with hypoparathyroidism.

CONCLUSIONS

This study describes for the first time the immune alterations in patients with hypoparathyroidism receiving conventional therapies, supporting the immunoregulatory role of PTH and proposing an explanation for the increased susceptibility to infections observed in epidemiological studies.

Combined Effects of Vitamin D Status, Renal Function and Age on Serum Parathyroid Hormone Levels

BACKGROUND

Vitamin D status and renal function are well-known independent predictors of serum parathyroid hormone (PTH) levels. We aimed to describe the combined effects of 25-hydroxy vitamin D (25(OH)D), glomerular filtration rate (GFR) and age on serum PTH levels across the whole clinical spectrum.

METHODS

We retrieved from our endocrinology center database all PTH measurement between 2012 and 2020 for which a simultaneous measurement of serum 25(OH)D, calcium and creatinine was available. Age, sex and diagnosis were available for all subjects. Intact PTH was measured using the same electrochemiluminescence assay.

RESULTS

There were 6,444 adults and 701 children without a diagnosis of hyper- or hypoparathyroidism or abnormal serum calcium levels. In adults with 25(OH)D≥12 ng/mL multiple regression models showed that serum PTH was negatively correlated with both 25(OH)D and GFR. Regression (-0.68 and -1.59 vs. -0.45 and -0.22 respectively), partial correlation (-0.16 and -0.35 vs. -0.12 and -0.10 respectively) and determination coefficients (0.14 vs. 0.031) were higher in CKD than in normal renal function. In subjects with 25(OH)D<12 ng/mL, GFR was the only significant predictor in those with CKD (β-coefficient=-2.5, r=-0.55) and 25(OH)D was the only significant predictor in those with normal renal function (β-coefficient=-2.05, r=-0.11). Increasing age was associated with higher PTH levels only in those with normal renal function and 25(OH)D≥12 ng/mL.

CONCLUSIONS

We showed that declining vitamin D and renal function have additive effects on serum PTH in subjects without vitamin D deficiency. In vitamin D deficient subjects this dependency is stronger but is not additive anymore.

Idiopathic Hypoparathyroidism: Still a Diagnostic Conundrum - A Tertiary Centre Experience

Idiopathic hypoparathyroidism leads to hypocalcemia and hyperphosphatasemia and usually has a genetic aetiology. The variable but often subtle signs and symptoms usually lead to a misdiagnosis of hypoparathyroidism. Case records of 32 patients of idiopathic hypoparathyroidism admitted over a period of five years were analysed. There was a lag period of 5.94 years from the onset of symptoms to the diagnosis. Carpopedal spasm was the most common indication for admission to the hospital. Trivial symptoms such as fatigue (84%) and paresthesia (62.5%) were the most common reported symptoms. A sum of 46.5% of the patients were on antiepileptic drugs before the correct diagnosis of hypoparathyroidism was made. This observation emphasized that Calcium profile should be obtained in patients with history of paresthesia and seizure to avoid the long delay in diagnosis of hypoparathyroidism.

Hypocalcemia After Thyroidectomy and Parathyroidectomy in a Pregnant Woman

Hypoparathyroidism during pregnancy is a very rare endocrine disorder. The majority of cases are postsurgical (75%). Managing pregnant or nursing women with hypoparathyroidism is challenging due to complications arising from either under- or overtreatment, including premature delivery or fetal death, abortion, stillbirth, perinatal death, and neonatal tetany. Specific adaptations are needed within each time period to meet the fetal, neonatal, and maternal calcium requirements. A systematic search was performed on PubMed using the search terms "pregnancy" and "hypoparathyroidism." Included were articles published in English between January 1, 1966, and January 1, 2018. We provide an overview of all published cases (n = 43) of hypoparathyroidism in pregnancy, including a case report of a 29-year-old pregnant woman who underwent a total thyroidectomy before her current pregnancy because of a therapy-resistantant Graves' disease. The procedure was complicated by postsurgical hypoparathyroidism. She carried out the pregnancy to term with minor complaints of paresthesia and muscle cramps. Furthermore, we discuss treatment, complications, and follow-up of hypoparathyroidism in pregnancy. Treatment of hypoparathyroidism in pregnancy should still be individualized, depending on the patient's complaints and serum levels of calcium, which should be maintained in the lower normal range of 2.15 to 2.55 mmol/l, according to the literature. We recommend monitoring calcium levels every 3 to 4 weeks throughout the pregnancy, within 1 week postpartum, and monthly during lactation to ensure normocalcemia.

Congenital Hypoparathyroidism Associated With Elevated Circulating Nonfunctional Parathyroid Hormone Due to Novel PTH Mutation

CONTEXT

Familial hypoparathyroidism has a heterogeneous presentation where patients usually have low parathyroid hormone (PTH) levels due to impaired production or secretion. This contrasts with pseudohypoparathyroidism, in which PTH resistance is usually associated with an elevated serum PTH. High levels of circulating PTH can also be due to bioinactive PTH, which is difficult to distinguish from pseudohypoparathyroidism on biochemical grounds.

CASE DESCRIPTION

We report on 2 sisters from consanguineous parents who presented with tetany at birth and were diagnosed with congenital hypocalcemia. Serum PTH levels were normal for many years, but progressively increased in midadulthood to greater than 100x the upper limit of normal on multiple assays. Homozygosity mapping was performed on 1 sister that demonstrated loss of heterozygosity (LOH) around PTH. Sequencing revealed a previously unreported variant, c.94T>C, predicting a codon change of p.Ser32Pro that is biologically inactive.

CONCLUSIONS

This case report shows a previously unreported unusual biochemical phenotype of a rising PTH in the context of a novel PTH mutation. This expands the evolving genotypes associated with hypoparathyroidism without established gene mutations.

Alternate-day calcium dosing may be an effective treatment option for chronic hypoparathyroidism

PURPOSE

Conventional treatment of chronic hypoparathyroidism consists of oral calcium supplements and active vitamin D analogs; however, some patients are unable to meet treatment goals despite the high dosage of oral calcium supplementation. We aimed to investigate the effectiveness of alternate-day oral calcium intake in patients with uncontrolled chronic hypoparathyroidism.

METHODS

In this retrospective cohort study, we evaluated 66 patients with chronic hypoparathyroidism who were admitted to our hospital between January 2017 and January 2019. Fourteen patients receiving ≥ 2000 mg/day oral elemental calcium and who were admitted to emergency department or our outpatient clinic at least once in the last 3 months for hypocalcemia requiring intravenous calcium replacement were switched to the alternate-day dosing regimen in which patients took calcium orally every other day. We collected and analyzed patients' medical history information, serum and urinary parameters over a 3-month period prior to and following the treatment.

RESULTS

Before alternate-day dosing regimen, median oral calcium intake was 3750 mg/day, oral calcitriol intake was 0.88 mcg/day, serum calcium levels were 7.71 mg/dL, serum phosphate levels were 5.35 mg/dL, and 24-h urine calcium levels were 165 mg/day. Following alternate-day dosing regimen, median oral calcium intake was 1500 mg/day, oral calcitriol intake was 0.88 mcg/day, serum calcium levels were 8.25 mg/dL, serum phosphate levels were 5 mg/dL, and 24-h urine calcium levels were 210.5 mg/day. After alternate-day dosing regimen, oral calcium intake decreased and serum calcium levels increased. The number of emergency visits dropped from 21 to 3 after alternate-day dosing regimen.

CONCLUSION

Patients with uncontrolled chronic hypoparathyroidism could be controlled more effectively with alternate-day dosing regimen.

Characteristics of hypoparathyroidism in Colombia: data from a single center in the city of Medellín

OBJECTIVE

Hypoparathyroidism is a rare condition, whose most common etiology is complications of neck surgery. The aim of the study was to identify the clinical and biochemical profile of the patients with diagnosis of hypoparathyroidism, including the frequency of symptoms, clinical signs, long-term complications and disease control. Additionally, the study sought to know what the medication profile was, and the doses required by the patients.

SUBJECTS AND METHOD

A retrospective cohort study was conducted wherein all patients with ICD-10 codes associated with hypoparathyroidism between 2011 and 2018 at the Hospital Universitario San Vicente Fundación were included. We investigated the etiology of the disease; biochemical profile including lowest serum calcium, highest serum phosphorus, 25OHD levels, calciuria and calcium/phosphorus product; medication doses, disease control, and presence of complications, especially renal and neurologic complications were also evaluated.

RESULTS

The cohort included 108 patients (99 women/9 men) with a mean age of 51.6 ± 15.6 years. The main etiology was postoperative (93.5%), the dose of elemental calcium received was relatively low (mean 1,164 mg/day), and in only 9.2% of cases more than 2,500 mg/day of elemental calcium was necessary. We were able to evaluate the follow-up in 89 patients, and found that only 57.3% met the criteria for controlled disease.

CONCLUSION

The clinical profile of patients with hypoparathyroidism in our cohort is similar to that described in other international studies, with predominantly postoperative etiology. With standard therapy, only adequate control is achieved in a little more than half of patients. Arch Endocrinol Metab. 2020;64(3):282-9.

Postoperative Hypoparathyroidism After Total Thyroidectomy in Children

BACKGROUND

Postoperative hypocalcemia because of hypoparathyroidism is the most common complication of total thyroidectomy in children. We hypothesized that most children with postoperative hypocalcemia would be eucalcemic by 12 mo and sought to define risk factors for permanent hypoparathyroidism.

METHODS

We retrospectively reviewed children who underwent total thyroidectomy at a single children's hospital from 2012 to 2019. Patients with prior neck surgery were excluded. Indication for operation, final pathologic diagnosis, and postoperative serum calcium up to 12 mo were recorded. Permanent hypoparathyroidism was defined as supplemental calcium requirement beyond 1 y postoperatively.

RESULTS

Sixty-eight patients underwent total thyroidectomy. Graves' disease was the most common benign indication for surgery (38 patients). Twenty-six patients (38%) had cancer on final pathology. Central lymph node dissection (CLND) was performed in 12 cancer patients. Twenty-eight patients (41%) had postoperative hypocalcemia. Eight patients (12%) had hypocalcemia at 6 mo. Risk factors for hypoparathyroidism at 6 mo were a cancer diagnosis (odds ratio [OR] 6.7; P = 0.02), CLND (OR 12.6; P < 0.01), and parathyroid tissue in the surgical specimen on pathologic analysis (OR 19.5; P < 0.01). Only two patients (3%) developed permanent hypoparathyroidism, both of whom had thyroidectomy for cancer and underwent CLND.

CONCLUSIONS

Children with thyroid cancer are at high risk for postoperative hypocalcemia after total thyroidectomy. The risk is further increased by CLND, which should be performed selectively. A majority of patients with hypoparathyroidism at 6 mo postoperatively regain normal parathyroid function by 1 y. Permanent hypoparathyroidism in children after total thyroidectomy at a pediatric endocrine surgery center is rare.

Burden of illness in not adequately controlled chronic hypoparathyroidism: Findings from a 13-country patient and caregiver survey

OBJECTIVE

To address knowledge gaps regarding burdens associated with not adequately controlled chronic hypoparathyroidism.

DESIGN

Global patient and caregiver survey.

STUDY POPULATIONS

Patients with chronic hypoparathyroidism not adequately controlled on conventional therapy and their caregivers.

MEASUREMENTS

Health-related quality of life (HRQoL) and health status were evaluated using the 36-item Short Form version 2 (SF-36 v2.0) and Five-Level EuroQoL 5 Dimensions (EQ-5D-5L) instruments, respectively. Hypoparathyroidism-associated symptoms were assessed by a disease-specific Hypoparathyroidism Symptom Diary and caregiver burden via the Modified Caregiver Strain Index (MCSI).

RESULTS

Data were obtained from 398 patients and 207 caregivers. Patients' self-rated hypoparathyroidism-related symptom severity was none (3%), mild (32%), moderate (53%) or severe (12%). Per the Hypoparathyroidism Symptom Diary, patients reported moderate, severe or very severe symptoms of physical fatigue (73%), muscle cramps (55%), heaviness in limbs (55%) and tingling (51%) over a 7-day recall period. Impacts (rated 'somewhat' or 'very much') were reported by 84% of patients for ability to exercise, 78% for sleep, 75% for ability to work and 63% for family relationships. Inverse relationships were observed between patient self-rated overall symptom severity and HRQoL and health status assessment scores-the greater the symptom severity, the lower the SF-36 and EQ-5D-5L scores. Caregiver burden increased with patient self-rated symptom severity: none, 1.7 MCSI; mild, 5.4 MCSI; moderate, 9.5 MCSI; and severe, 12.5 MCSI.

CONCLUSION

Patients with not adequately controlled hypoparathyroidism reported substantial symptoms and impacts. Greater patient symptom severity was associated with decreased patient HRQoL and health status assessments and increased caregiver burden.

The Effect of Bariatric Surgery on Premalignant Endometrial Pathology in Morbidly Obese Patients

AIM

To investigate the effect of bariatric surgery on premalignant endometrial pathology in postmenopausal morbidly obese patients. Material and Methods: Between 2014 and 2019, in "Ponderas" Academic Hospital six postmenopausal morbidly obese patients with premalignant endometrial pathology were submitted to bariatric surgery consisting of sleeve gastrectomy. Results: At the time of bariatric surgery, the mean body mass index (BMI) value was of 43.5 kg/m2 (range = 41.5 kg/m2 - 48.5 kg/m2) while the mean age was of 61 years (range = 58 - 63 years). The preoperative biopsy of the endometrial lining demonstrated the presence of simple endometrial hyperplasia in five cases and complex endometrial hyperplasia in one case while the mean thickness of the endometrial lining at magnetic resonance imaging (MRI) was of 2.1 cm (range = 1.5 - 2.8 cm). At one year follow-up, the mean BMI was of 26.5 kg/m2 (range = 24 kg/m2 - 28 kg/m2) while the mean thickness estimated at MRI was of 0.8 cm (range = 0.5 - 1.1 cm). The biopsy demonstrated the presence of normal endometrium in four cases and simple hyperplasia in two cases. Conclusions: Bariatric surgery seems to have an important effect on premalignant endometrial conditions. Therefore, bariatric surgery and consecutive weight loss might decrease the risk of malignant transformation in postmenopausal morbidly obese women.

A Rapid Intraoperative Parathyroid Hormone Assay Based on the Immune Colloidal Gold Technique for Parathyroid Identification in Thyroid Surgery

OBJECTIVE

A novel immunochromatographic test strip method was developed to detect tissue parathyroid hormone (PTH) using the immune colloidal gold technique (ICGT). The accuracy and application value of this method for intraoperative parathyroid identification were evaluated.

METHODS

Serum samples were collected to measure PTH by both ICGT and electrochemiluminescence immunoassay (ECLIA). Patients who underwent unilateral and total thyroidectomy were enrolled to evaluate the feasibility and clinical efficacy of rapid intraoperative identification of parathyroid glands via PTH determination using ICGT. Two sample preparation methods, fine needle aspiration (FNA) and tissue block homogenate (TBH), were used for PTH-ICGT analysis.

RESULTS

Bablok analysis showed a linear relationship between the serum PTH measurements obtained by ICGT and ECLIA. Non-parathyroid tissues had much lower PTH concentrations (14.8 ± 2.1 pg/ml, n = 97) detected by ICGT, compared to the parathyroid gland tissues (955.3 ± 16.1 pg/ml, n = 79; P < 0.0001), With biopsy results as the standard, ICGT showed higher diagnosis rates as compared with direct visual inspection, for identifying both parathyroid glands (97.4 vs. 78.2%) and non-parathyroid tissues (100 vs. 68.9%). The cut-off values for parathyroid identification by FNA and TBH methods were 63.99 and 136.30 pg/ml, respectively. The detection time was 2 min by TBH method for in vitro tissue detection and 6 min by FNA method for in situ tissue detection, both of which were faster than traditional intraoperative cryopathological examination (usually >30 min). Intraoperative application of ICGT method was associated with higher postoperative serum calcium and blood PTH levels at 1 and 3 months as well as a lower incidence of postoperative transient hypocalcemia, as compared with direct visual inspection.

CONCLUSION

PTH-ICGT assay shows high potential as a rapid, novel alternative for intraoperative parathyroid identification.

Type 2 diabetes mellitus complicated with idiopathic hypoparathyroidism where poor glycaemic control was associated with low adherence to exercise and medication due to hypocalcaemia

We report a rare case of type 2 diabetes mellitus (T2DM) complicated with idiopathic hypoparathyroidism. A 36-year-old Japanese man was admitted to our hospital owing to poor glycaemic control and hypocalcaemia. The patient had myalgia resulting from hypocalcaemia, which prevented adequate exercise. He considered the onset of myalgia to be an adverse event of oral hypoglycaemic agents and reduced compliance to medication; however, his serum calcium level was never measured. Treatment for hypocalcaemia immediately improved the myalgia, facilitating regular exercise therapy and ensuring compliance with prescribed medications, as the now-resolved myalgia was no longer perceived to be an adverse effect of glucose-lowering agents; this improved glycaemic control. Although hypoparathyroidism is a rare disease, it is necessary to assess serum calcium levels in patients with T2DM, particularly in cases presenting with unidentified complaints such as myalgia.

Postoperative Hypoparathyroidism in Patients After Total Thyroidectomy - Experience of a Tertiary Center in Romania

Background: Post-surgical hypoparathyroidism (PoSH) is a common long-term complication after thyroid surgery. The reported median (range) incidence rates of temporary and permanent PoSH was 27% (19 - 38%) and 1% (0 - 3%) respectively. Material and Methods: We retrospectively analyzed the files of 552 patients who underwent thyroidectomy in our surgery department between 2015- 2017 with the aim to assess the prevalence of PoSH and to identify patient and disease related factors associated with postoperative hypocalcemia. Results: 171 (30.97%) patients developed PoSH, 88.37% transient, 11.63% permanent. The median (IQR) duration of postoperative hypocalcemia was 60 (67.5) days. Preoperative biological parameters were similar in PoSH and the control group, except median (IQR) serum magnesium level that was significantly higher in PoSH group [2.04 (0.17) vs. 1.89 (0.28) mg/dl, p=0.005]. In the subgroup of patients with thyroid carcinoma the surgery duration was longer in PoSH patients compared to the control group [135 (60) vs. 110 (43) minutes, p=0.020]. In patients with PoSH, median post-operative serum calcium was significantly higher in patients with reported difficult surgery [8.2 (0.2) vs. 7.9 (0.6) mg/dl, p=0.043] and the mean serum calcium decrease was higher in patients with cervical neck dissection and lymphadenectomy (1.94 +-0.59 vs. 1.68 +-0.56 mg/dl, p=0.033). Conclusions: Our data show a high prevalence of PoSH that is likely to increase given the rising number of thyroid surgeries being performed. Further research is needed in order to better define this condition, to establish appropriate treatment and preventive measures.

Quality of Life in Hypoparathyroidism Improves With rhPTH(1-84) Throughout 8 Years of Therapy

CONTEXT

Calcium and vitamin D treatment does not improve reduced quality of life (QOL) in hypoparathyroidism. Recombinant human (rh) PTH(1-84) therapy improves QOL metrics for up to 5 years. Data on QOL beyond this time point are not available.

OBJECTIVES

To evaluate the effects of 8 years of rhPTH(1-84) therapy on QOL and factors associated with long-term benefit.

DESIGN

Prospective, open-label trial.

SETTING

Referral center.

PATIENTS

Twenty patients with hypoparathyoidism.

MAIN OUTCOME MEASURES

RAND 36-Item Short Form Health Survey (SF-36).

RESULTS

rhPTH therapy led to substantial improvement in five of the eight SF-36 domains [vitality, social functioning (SF), mental health (MH), bodily pain (BP) and general health] and three of these domains (SF, MH, BP) were no longer lower than the reference population. The improvement in the mental component summary (MCS) score was sustained through 8 years, while the physical component summary (PCS) score improved through 6 years. A lower baseline QOL score was associated with greater improvement. A threshold value <238 (MCS) and <245 (PCS) predicted long-term improvement in 90% and 100% of the cohort, respectively. In patients whose calcium supplementation was reduced, MCS and PCS scores improved more than those whose supplementation did not decline to the same extent. Improvement in PCS was greater in patients whose calcitriol dosage was reduced and duration of disease was shorter.

CONCLUSIONS

rhPTH(1-84) improves long-term well-being in hypoparathyroidism. The improvements are most prominent in those with impaired SF-36 at baseline and those whose requirements for conventional therapy decreased substantially.

Auditing the Efficacy and Safety of Alfacalcidol and Calcium Therapy in Idiopathic Hypoparathyroidism

CONTEXT

Patients with hypoparathyroidism are treated with vitamin D and calcium. PTH is an emerging option because of its physiological action. It is important to assess the efficacy and shortcomings of conventional therapy.

OBJECTIVE

We assessed the efficacy and safety of alfacalcidol in a large cohort of patients with idiopathic hypoparathyroidism (IH) and identified a subset who could be treated without oral calcium.

DESIGN AND SETTING

Observational study at tertiary care center.

SUBJECTS AND METHODS

We assessed 92 patients with IH who were receiving alfacalcidol and oral calcium to maintain an optimal serum total calcium level of 8.0 to 8.5 mg/dL during routine follow-up. Patients with suboptimal control were provided free medicines and followed up frequently. Oral calcium and alfacalcidol doses were titrated sequentially to determine the minimum doses for optimal calcium control. Serum phosphate level, 1,25-dihydroxyvitamin D, fractional excretion of phosphorus (FEPh), and hypercalciuria (urine calcium-to-creatinine ratio, >0.2) were assessed at each step of titration.

RESULTS

Only 38% of patients had optimal calcium control during routine follow-up. With good compliance, all achieved optimal serum calcium and 1,25-dihydroxyvitamin D levels and 43% of patients could stop taking oral calcium. Hyperphosphatemia, hypercalciuria, and low FEPh persisted at all stages of therapy. Serum phosphorus levels normalized when the serum calcium level increased to 9.9 mg/dL, but this level of serum total calcium was associated with hypercalciuria in 90% of patients.

CONCLUSION

Alfacalcidol is effective in achieving calcemic control in IH. Calcemic control without oral calcium was achieved in 43% of patients receiving alfacalcidol. However, optimal calcium control was associated with hyperphosphatemia and hypercalciuria in most patients.

MANAGEMENT OF ENDOCRINE DISEASE: Hypoparathyroidism in pregnancy: review and evidence-based recommendations for management

Purpose Review calcium homeostasis in pregnancy and provide evidence-based best practice recommendations for the management of hypoparathyroidism in pregnancy. Methods We searched MEDLINE, EMBASE and Cochrane databases from January 2000 to April 1, 2018. A total of 65 articles were included in the final review. Conclusions During pregnancy, calcitriol levels increase by two- to-three-fold resulting in enhanced intestinal calcium absorption. The renal filtered calcium load increases leading to hypercalciuria. PTHrP production by the placenta and breasts increases by three-fold, and this may lower the doses of calcium and calcitriol required during pregnancy in mothers with hypoparathyroidism. The literature however describes a wide variation in the required doses of calcium and calcitriol during pregnancy in hypoparathyroid mothers, with some women requiring higher doses of calcitriol, whereas others require lower doses. Close monitoring is necessary as hypercalcemia in the mother may suppress the fetal parathyroid gland development. Also hypocalcemia in the mother is harmful as it may result in secondary hyperparathyroidism in the fetus. This may be associated with demineralization of the fetal skeleton and the development of intrauterine fractures. Inadequate treatment of hypoparathyroidism may also result in uterine contractions and an increased risk of miscarriage. Treatment targets during pregnancy are to maintain a low normal serum calcium. Calcium, calcitriol and vitamin D supplements are safe during pregnancy. Close monitoring of the mother with a multidisciplinary team is advised for optimal care. If calcium homeostasis is well controlled during pregnancy, most women with hypoparathyroidism have an uncomplicated pregnancy and give birth to healthy babies.

Heterozygous Mutations in TBX1 as a Cause of Isolated Hypoparathyroidism

CONTEXT

Most cases of autosomal dominant isolated hypoparathyroidism are caused by gain-of-function mutations in CASR or GNA11 or dominant negative mutations in GCM2 or PTH.

OBJECTIVE

To identify the genetic etiology for dominantly transmitted isolated hypoparathyroidism in two multigenerational families with 14 affected family members.

METHODS

We performed whole exome sequencing of DNA from two families and examined the consequences of mutations by minigene splicing assay.

RESULTS

We discovered disease-causing mutations in both families. A splice-altering mutation in TBX1 (c.1009+1G>C) leading to skipping of exon 8 (101 bp) was identified in 10 affected family members and five unaffected subjects of family A, indicating reduced penetrance for this point mutation. In a second family from France (family B), we identified another splice-altering mutation (c.1009+2T>C) adjacent to the mutation identified in family A that results in skipping of the same exon; two subjects in family B had isolated hypoparathyroidism, whereas a third subject manifested the clinical triad of the 22q11.2 deletion syndrome, indicative of variable expressivity.

CONCLUSIONS

We report evidence that heterozygous TBX1 mutations can cause isolated hypoparathyroidism. This study adds knowledge to the increasingly expanding list of causative and candidate genes in isolated hypoparathyroidism.

Efficacy and safety of long-term management of patients with chronic post-surgical hypoparathyroidism

PURPOSE

To evaluate adherence to European Society of Endocrinology guidelines and risk of renal complications in patients with chronic post-operative hypoparathyroidism (PO-HypoPT) treated with calcium and activated vitamin D metabolites.

METHODS

We evaluated 90 adult patients (68 females and 22 males) with chronic (3 years) PO-HypoPT. Total albumin-corrected (Alb-Ca) and ionized serum calcium, phosphate, creatinine, PTH, and 24-h urinary calcium were measured; renal ultrasound was also performed. Healthy hospital employers (n = 142) were used as control.

RESULTS

Complete data were available in 82 patients. Twenty-eight (34.1%) met four targets (Alb-Ca, phosphate, calcium phosphate product and 24-h urinary calcium), 36 (43.9%) three, 17 (20.7%) two, and 1 (1.2%) one. Thirteen (14.4%) had Alb-Ca value below and 18 (20.0%) above the target range and 54.9% 24-h urinary calcium above the upper normal limit. Seven (7.7%) has increased serum phosphate and none an increased calcium phosphate product. Eleven (12.2%) patients had eGFR < 60 mL/min × 1.73 m². Nephrolithiasis was present in 27 (30%) patients. Compared with the controls, patients had lower Alb-Ca (8.9 ± 0.5 vs. 9.5 ± 0.3 mg/dL, P 0.0001) and a higher rate of kidney stones, mostly asymptomatic [27/90 (30%) vs 7/142 (5%), P < 0.0001, odd ratio 8.2 (3.4-19.9)]. Fifty-seven patients had ≥ four serum Ca²⁺ determinations during follow-up. Forty (70.2) patients had values within the target range in > 50% of cases, 18 in > 75%, and only 2 in 100%. Two patients never had values in the target range.

CONCLUSIONS

Treatment of chronic PO-HypoPT with calcium and activated vitamin D metabolites is suboptimal and associated with an increased risk of renal complications.

The timing of parathyroid hormone measurement defines the cut-off values to accurately predict postoperative hypocalcemia: a prospective study

PURPOSE

Serum intact parathyroid hormone (iPTH) level is an early marker of post-thyroidectomy hypocalcemia. However, lack of methodological standardization to define timing and cut-off points of iPTH measurement limit its clinical applicability. Here, we evaluated the relationship between two distinct postoperative time sampling and iPTH accuracy on predicting hypocalcemia.

METHODS

iPTH was measured within 4 h after surgery (iPTH 4 h) and on the morning of the first postoperative day (iPTH 1st PO). Hypocalcemia was defined by levels of total calcium corrected by serum albumin ≤ 8.0 mg/dL and/or by the presence of symptoms. The most accurate iPTH cut-off point for hypocalcemia prediction was established from a ROC curve comparing both time-points.

RESULTS

The study included 101 patients. The mean age was 52.4 ± 12.9 years, 93 were women (92.1%) and 69 patients underwent total thyroidectomy (68.3%). Hypocalcemia occurred in 25 patients (24.8%), of whom 12 were symptomatic. Total thyroidectomy, longer duration of surgery, surgical complications related to parathyroid glands and lower levels of iPTH 4 h and iPTH 1st PO were associated with postoperative hypocalcaemia (all P < 0.05). Using the ROC curve, the optimal cut-off points were 19.55 pg/mL and 14.35 pg/mL for iPTH 4 h and iPTH 1st PO, respectively. The comparison of the AUC showed no significant difference between these two points of evaluation (0.935 vs. 0.940; P = 0.415).

CONCLUSIONS

Serum iPTH levels measured within 4 h or on the first morning after surgery are predictors of postoperative hypocalcemia. Notably, both time-points have the same accuracy to predict postoperative hypocalcemia (with different cutoff points).

Diagnostic and Therapeutic Aspects of Iatrogenic Hypoparathyroidism

Postsurgical hypoparathyroidism is the most common cause of chronic hypocalcemia. This condition may occur after removal of all parathyroid glands or after interruption of the blood supply to the parathyroid glands during thyroidectomy and radical neck dissection. The severity of the clinical presentation of hypocalcemia may vary from an asymptomatic laboratory finding to a severe life-threatening condition. Persistent hypoparathyroidism requires treatment that must be maintained throughout the patient's lifetime, and for this reason care is required to avoid complications. In this review the most relevant aspects of calcium homeostasis and its alteration in hypoparathyroidism are briefly discussed. In addition, the main approaches to treatment of the hypocalcemic state are presented.

Recombinant Human Parathyroid Hormone Effect on Health-Related Quality of Life in Adults With Chronic Hypoparathyroidism

CONTEXT

Reduced health-related quality of life (HRQoL) is common in patients with hypoparathyroidism treated conventionally with calcium and active vitamin D supplements.

OBJECTIVE

To examine the effects of recombinant human parathyroid hormone [rhPTH(1-84)] on HRQoL as measured by the 36-Item Short-Form Health Survey (SF-36) during a multinational, randomized, placebo-controlled study.

PATIENTS

Adults (N = 122) with chronic hypoparathyroidism.

INTERVENTION(S)

After an optimization period when calcium and/or active vitamin D supplements were adjusted to reach target serum calcium levels (8.0 to 9.0 mg/dL; 2.0 to 2.2 mmol/L), patients were randomly assigned to receive placebo (n = 39) or rhPTH(1-84) (n = 83) (starting dose, 50 μg/d, could be titrated up to 100 μg/d); supplement doses were adjusted to maintain target serum calcium levels.

MAIN OUTCOME MEASURE(S)

Change from baseline (postoptimization, at randomization) to week 24 in HRQoL as assessed by the SF-36.

RESULTS

Overall, the between-group differences were not statistically significant. However, in the rhPTH(1-84) group, there were significant improvements in the physical component summary score (P = 0.004), and in body pain (P < 0.05), general health (P < 0.05), and vitality (P < 0.001) domains as compared with baseline values. In the placebo group, there were no significant changes for any domains. The magnitude of change between 0 and 24 weeks in SF-36 scores was negatively correlated with baseline scores, such that patients with lower HRQoL at baseline were more likely to experience improvement in response to treatment.

CONCLUSION

Treatment with rhPTH(1-84) may improve HRQoL in adults with hypoparathyroidism.

PTH(1-34) for Surgical Hypoparathyroidism: A 2-Year Prospective, Open-Label Investigation of Efficacy and Quality of Life

CONTEXT

Daily parathyroid hormone (PTH) (1-34) administrations can reduce the required total daily dose of calcium and calcitriol and restore normocalcemia in refractory hypoparathyroidism. However, most PTH(1-34) trials have been conducted on small cohorts including subjects with hypoparathyroidism of various etiologies, and quality of life (QOL) was not investigated.

OBJECTIVE

To investigate the effects of 24-month PTH(1-34) treatment in a homogeneous cohort of adult subjects with postoperative hypoparathyroidism and to evaluate QOL changes.

DESIGN

Prospective open-label study.

SETTING

Italian multicenter study.

PARTICIPANTS

42 subjects.

INTERVENTION

Twice-daily PTH(1-34) 20 μg subcutaneous injection.

MAIN OUTCOME MEASURES

Calcium and vitamin D supplementation requirements, serum calcium, phosphate, and urinary calcium excretion (3, 6, 12, 18, 24 months). At baseline and at 6 and 24 months, QOL was evaluated by the RAND 36-Item Short Form (SF-36) Health Survey, covering eight domains of physical and mental health.

RESULTS

Mean serum calcium concentration significantly increased from baseline to 3 months (7.6 ± 0.6 vs 8.9 ± 1.1 mg/dL, P < 0.001) and remained stable until the end of the study, despite reductions in calcium and vitamin D supplementation. Phosphate levels gradually decreased from baseline to 6 months (4.3 ± 1.1 vs 3.9 ± 0.6 mg/dL, P < 0.019), remaining stable until 24 months. Serum alkaline phosphatase and calcium excretion gradually increased from baseline to 24 months. Data from SF-36 showed a significant improvement in the mean scores of all eight domains (P < 0.001).

CONCLUSION

This study demonstrates the efficacy and safety of PTH(1-34) to treat adult patients with postsurgical hypoparathyroidism. PTH(1-34) may improve their mental and physical health.

Postoperative hypoparathyroidism in patients after total thyroidectomy - retrospective analysis

OBJECTIVES

Hypoparathyroidism is the most frequent complication of thyroidectomy. The incidence rates of temporary and permanent postoperative hypoparathyroidism vary from 7 to more than 60% and from 0 to 9%, respectively.

DESIGN

The aim of the study has been to evaluate the incidence of hypoparathyroidism and clinical manifestations of hypocalcaemia after total thyroidectomy, as well as assess factors that affect the frequency of the symptomatic hypocalcaemia, and benefits resulting from the measurement of parathyroid hormone (PTH) concentration on the first day after thyroidectomy.

SETTING

The studied group consisted of 330 patients after total thyroidectomy, while the control group consisted of 86 patients who underwent total resection of one lobe only or subtotal thyroidectomy.

RESULTS

Based on the measurements of serum PTH concentration on the first day after total thyroidectomy, postoperative hypoparathyroidism was diagnosed in 48% of patients. After total thyroidectomy, the frequency of clinical symptoms of hypocalcaemia was twice less than the incidence of hypoparathyroidism confirmed by biochemical testing. Total thyroidectomy occurred to be an independent factor of the increased risk of postoperative hypoparathyroidism. This risk was even higher in the cases widened by lymphadenectomy, and among patients with Graves' disease. In the group of patients with decreased serum PTH concentration the occurrence of clinical symptoms of hypocalcaemia significantly depended on serum PTH concentration - patients with lower PTH levels reported paresthesias more frequently.

CONCLUSIONS

Serum PTH levels below 5 pg/ml seems to be a good prognostic factor of the occurrence of hypocalcaemia symptoms. The information about low PTH concentration allows to start the pharmacotherapy faster and avoid clinical manifestation of hypocalcaemia.

Treatment of severe hypocalcaemia due to osteoblastic metastases in a patient with post-thyroidectomy hypoparathyroidism with 153Sm-EDTMP

Symptomatic hypocalcaemia is an uncommon finding in patients with malignant tumours. We describe a patient with advanced metastatic breast cancer who developed severe hypocalcaemia caused by the combination of osteoblastic metastases and a permanent postoperative hypoparathyroidism. The patient failed to be treated with the conventional replacement therapy and was submitted effectively to radionucleotide therapy with ¹⁵³Sm.

Hypoparathyroidism: Less Severe Hypocalcemia With Treatment With Vitamin D2 Compared With Calcitriol

Context

Options for chronic treatment of hypoparathyroidism include calcitriol, recombinant human parathyroid hormone, and high-dose vitamin D (D2). D2 is used in a minority of patients because of fear of prolonged hypercalcemia and renal toxicity. There is a paucity of recent data about D2 use in hypoparathyroidism.

Objective

Compare renal function, hypercalcemia, and hypocalcemia in patients with hypoparathyroidism treated chronically with either D2 (D2 group) or calcitriol.

Design, Setting, and Patients

A retrospective study of patients with hypoparathyroidism treated at the University of Maryland Hospital. Participants were identified by a billing record search with diagnosis confirmed by chart review. Thirty patients were identified; 16 were treated chronically with D2, 14 with calcitriol. Data were extracted from medical records.

Main Outcome Measures

Serum creatinine and calcium, hospitalizations, and emergency department (ED) visits for hypercalcemia and hypocalcemia.

Results

D2 and calcitriol groups were similar in age (58.9 ± 16.7 vs 50.9 ± 22.6 years, P = 0.28), sex, and treatment duration (17.8 ± 14.2 vs 8.5 ± 4.4 years, P = 0.076). Hospitalization or ED visits for hypocalcemia occurred in none of the D2 group vs four of 14 in the calcitriol group (P = 0.03); three in the calcitriol group had multiple ED visits. There were no differences between D2 and calcitriol groups in hospitalizations or ED visits for hypercalcemia, serum creatinine or calcium, or kidney stones.

Conclusion

We found less morbidity from hypocalcemia in hypoparathyroid patients treated chronically with D2 compared with calcitriol and found no difference in renal function or morbidity from hypercalcemia. Treatment with D2 should be considered in patients with hypoparathyroidism, particularly in those who experience recurrent hypocalcemia.

Parathyroid score can predict the duration of required calcium supplementation after total thyroidectomy

BACKGROUND

Postoperative hypoparathyroidism is the most common complication after total thyroidectomy, owing to unintentional injury or decreased blood flow to the parathyroid glands. Prediction of postoperative hypoparathyroidism would be helpful for surgeons to manage postoperative hypocalcemia. In this study, we scored the discoloration of the parathyroid glands using a new parathyroid scoring system and evaluated the correlation between the parathyroid score and duration of required calcium supplementation after total thyroidectomy.

METHODS

A total of 316 patients undergoing total thyroidectomy between November 2009 and April 2010 were enrolled in this retrospective study. Parathyroid scoring was performed by one experienced surgeon. The status of each of the 4 parathyroid glands was classified as normal color (3 points), slightly discolored (2 points), dark discoloration (1 point), or loss of the gland (0 points), resulting in possible total scores of 0-12. Serum parathyroid hormone (PTH), serum calcium, and ionized calcium concentrations were measured at 2 hours, 2 weeks, 3 months, 6 months, and 1 year after surgery. Patients were also divided into three groups based on the duration of required calcium supplementation: no required supplementation (n = 260, 82.3%), required supplementation for <6 months (n = 38, 12%), and required supplementation for ≥6 months (n = 18, 5.75%).

RESULTS

Parathyroid scores were positively correlated with ionized PTH concentrations at 2 hours (r = 0.053, p < 0.001), 2 weeks (r = 0.056, p < 0.001), 3 months (r = 0.032, p<0.001), 6 months (r = 0.072, p < 0.001), and 1 year (r = 0.071, p < 0.001) after thyroidectomy. Parathyroid scores were significantly and inversely associated with the duration of required calcium supplementation (p = 0.001).

CONCLUSIONS

Parathyroid scores at the end of surgery might be helpful for predicting the degree of postoperative hypocalcemia after total thyroidetomy.

Effects of parathyroid hormone rhPTH(1-84) on phosphate homeostasis and vitamin D metabolism in hypoparathyroidism: REPLACE phase 3 study

In hypoparathyroidism, inappropriately low levels of parathyroid hormone lead to unbalanced mineral homeostasis. The objective of this study was to determine the effect of recombinant human parathyroid hormone, rhPTH(1-84), on phosphate and vitamin D metabolite levels in patients with hypoparathyroidism. Following pretreatment optimization of calcium and vitamin D doses, 124 patients in a phase III, 24-week, randomized, double-blind, placebo-controlled study of adults with hypoparathyroidism received subcutaneous injections of placebo or rhPTH(1-84) (50 µg/day, titrated to 75 and then 100 µg/day, to permit reductions in oral calcium and active vitamin D doses while maintaining serum calcium within 2.0-2.2 mmol/L). Predefined endpoints related to phosphate homeostasis and vitamin D metabolism were analyzed. Serum phosphate levels decreased rapidly from the upper normal range and remained lower with rhPTH(1-84) (P < 0.001 vs. placebo). At week 24, serum calcium-phosphate product was lower with rhPTH(1-84) vs. placebo (P < 0.001). rhPTH(1-84) treatment resulted in significant reductions in oral calcium dose compared with placebo (P < 0.001) while maintaining serum calcium. After pretreatment optimization, baseline serum 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]₂D) levels were within the normal range in both groups. After 24 weeks, 1,25(OH)₂D levels were unchanged in both treatment groups, despite significantly greater reductions in active vitamin D dose in the rhPTH(1-84) group. In hypoparathyroidism, rhPTH(1-84) reduces serum phosphate levels, improves calcium-phosphate product, and maintains 1,25(OH)₂D and serum calcium in the normal range while allowing significant reductions in active vitamin D and oral calcium doses.

Early Predictors of Post - Thyroidectomy Hypoparathyroidism

Thyroid surgery is the most commonly performed procedure in the field of endocrine surgery. Studies are still ongoing on the development of a single algorithm for diagnosis and care of patients at risk of postoperative hypoparathyroidism. The aim of the study was to determine the biochemical marker that would allow the most accurate diagnosis of patient groups at risk of developing hypoparathyroidism and to identify risk factors for this disorder.

MATERIAL AND METHODS

The prospective study included 142 consecutive patients undergoing total thyroidectomy for benign goiter from January 1st 2014 to December 31st 2015. Serum intact parathyroid hormone (iPTH), total calcium (Ca), phosphate (P), and magnesium (Mg) levels have been measured preoperatively and at 1, 6, 24, and 48 h postoperatively.

RESULTS

Clinical symptoms of hypoparathyroidism developed in 25 (17.6%) of 142 patients. The best diagnostic accuracy for hypoparathyroidism based on ROC curves was obtained for iPTH at 6h (AUC 0.942; 95% CI: 0.866-1.000, p<0.001) and its percentage change from baseline ΔiPTH at 6h (AUC 0.930; 95% CI: 0.858-1.000, p<0.001). In an multivariate analysis, the preoperative Ca level higher by 0.1 mmol/l, and iPTH level higher by 0.1 pmol/l were associated with a lower risk of hypoparathyroidism, by 68% (p=0.012) and 61% (p=0.007), respectively. A 1% decline in iPTH from baseline increased the risk of hypoparathyroidism by 15% (p<0.001).

CONCLUSIONS

The most reliable markers indicating a high risk of postoperative hypoparathyroidism are the decline in ΔiPTH at 6h by > 65% or iPTH level at 6h <1.57 pmol /l. A postoperative decline in iPTH levels is an independent risk factor for the development of hypoparathyroidism. Preoperative higher concentrations of Ca and iPTH are protective factors for the development of this disorder.

Long-Term Follow-Up and Treatment of Postoperative Permanent Hypoparathyroidism in Patients with Medullary Thyroid Carcinoma: Differences in Complete and Partial Disease

This study aimed to identify factors influencing long-term outcome in complete or partial postoperative hypoparathyroidism (parathyroid hormone ≤10 or >10 ng/l, respectively) in medullary thyroid carcinoma (MTC). It was designed as retrospective, long-term follow-up with single-center outpatient visits. Quality of treatment, renal calcification, and function were evaluated. In 33 patients with MTC and postoperative hypoparathyroidism, current medication includes: calcium (73%), calcitriol (73%), alfacalcidol (6%), dihydrotachysterol (3%), and cholecalciferol supplements (21%). Mean hypoparathyroidism duration was 15.9±9.4 years. Initially, 15% of patients received high cholecalciferol dosages. Initial calcium dosages were higher (1 542±1 179 mg/day) than final dosages (1 188 ± 595 mg/day) (p<0.05); calcitriol dosages remained constant. Over the median observation period of about 12 years it was found that serum calcium was within the target range (2.0-2.3 mmol/l) in 63% of visits, decreased (<2.0 mmol/l) in 20.4%, high-normal (2.4-2.6 mmol/l) in 15.8%, and increased (>2.65 mmol/l) in 0.9% of visits. Calcitriol dosages were 0.73±0.22 μg/day and 0.47±0.20 μg/day in patients with complete (n=13) and partial (n=20) hypoparathyroidism, respectively (p=0.008). Renal function decreased slightly during follow-up (eGFR: 102±22 vs. 90±27 ml/min). eGFR was negatively correlated with hypoparathyroidism duration (r=-0.35, p=0.05). Of 9 patients with renal calcification, 5 had received high initial cholecalciferol doses. eGFR was lower in patients with than in those without calcification (77±17 vs. 95±29 ml/min) (p=0.07). At least one tetanic episode occurred in 60.6% of patients, and 9% had repeated tetanic complaints. In conclusion, severity of hypoparathyroidism affects treatment: Partial hypoparathyroidism required lower calcitriol dosages than complete hypoparathyroidism. Renal calcifications occurred more frequently in patients treated initially with high cholecalciferol dosages. Impaired renal function was related to hypoparathyroidism duration and renal calcification.

Hypoparathyroidism and pseudohypoparathyroidism: etiology, laboratory features and complications

OBJECTIVES

To identify a clinical profile and laboratory findings of a cohort of hypoparathyroidism patients and determine the prevalence and predictors for renal abnormalities.

MATERIALS AND METHODS

Data from medical records of five different visits were obtained, focusing on therapeutic doses of calcium and vitamin D, on laboratory tests and renal ultrasonography (USG).

RESULTS

Fifty-five patients were identified, 42 females and 13 males; mean age of 44.5 and average time of the disease of 11.2 years. The most frequent etiology was post-surgical. Levels of serum calcium and creatinine increased between the first and last visits (p < 0.001 and p < 0.05, respectively); and serum levels of phosphate decreased during the same period (p < 0.001). Out of the 55 patients, 40 had USG, and 10 (25%) presented with kidney calcifications. There was no significant difference in the amount of calcium and vitamin D doses among patients with kidney calcifications and others. No correlation between serum and urinary levels of calcium and the presence of calcification was found. Urinary calcium excretion in 24h was significantly higher in patients with kidney calcification (3.3 mg/kg/d) than in those without calcification (1.8 mg/kg/d) (p < 0.05).

CONCLUSIONS

The reduction of hypocalcemia and hyperphosphatemia suggest an effectiveness of the treatment, and the increase in serum creatinine demonstrates an impairment of renal function during follow-up. Kidney calcifications were prevalent in this cohort, and higher urinary calcium excretion, even if still within the normal range, was associated with development of calcification. These findings suggest that lower rates of urinary calcium excretion should be aimed for in the management of hypoparathyroidism.

Standardization of A Physiologic Hypoparathyroidism Animal Model

Ideal hypoparathyroidism animal models are a prerequisite to developing new treatment modalities for this disorder. The purpose of this study was to evaluate the feasibility of a model whereby rats were parathyroidectomized (PTX) using a fluorescent-identification method and the ideal calcium content of the diet was determined. Thirty male rats were divided into surgical sham (SHAM, n = 5) and PTX plus 0, 0.5, and 2% calcium diet groups (PTX-FC (n = 5), PTX-NC (n = 10), and PTX-HC (n = 10), respectively). Serum parathyroid hormone levels decreased to non-detectable levels in all PTX groups. All animals in the PTX—FC group died within 4 days after the operation. All animals survived when supplied calcium in the diet. However, serum calcium levels were higher in the PTX-HC than the SHAM group. The PTX-NC group demonstrated the most representative modeling of primary hypothyroidism. Serum calcium levels decreased and phosphorus levels increased, and bone volume was increased. All animals survived without further treatment and did not show nephrotoxicity including calcium deposits. These findings demonstrate that PTX animal models produced by using the fluorescent-identification method, and fed a 0.5% calcium diet, are appropriate for hypoparathyroidism treatment studies.

Endoscopic thyroidectomy along with bilateral central neck dissection (ETBC) increases the risk of transient hypoparathyroidism for patients with thyroid carcinoma

Increasing number of patients with thyroid carcinoma, especially young female patients, prefer to choose endoscopic thyroidectomy with bilateral central neck dissection (ETBC) for perfect cosmetic effects. However, the incidence of hypoparathyroidism after ETBC has not been well studied. Ninety six patients with papillary thyroid carcinoma were enrolled. All patients, including 49 ETBC and 47 open surgery patients, underwent total thyroidectomy with bilateral central neck dissection (CND). Some patients also underwent lateral neck dissection simultaneously. The incidence of hypoparathyroidism and parathyroid hormone (PTH) level were examined. Patients in the open surgery group had more advanced lesions, with larger tumor (p = 0.000), older age (p = 0.000), and more serious local involvement. The dissection extent of the open group was significantly larger than that of the ETBC group (p = 0.006). In contrast, the ETBC group with less dissection extent showed a significantly higher incidence of transient hypoparathyroidism than the open group (59.2 vs. 29.6 %, p = 0.004). The average PTH decline of the ETBC group was significantly higher than that of the open group on postoperative day 1 (POD1) (32.1 vs. 21.6 pg/ml, p = 0.010). Furthermore, the ETBC group had a significantly higher portion of patients with a PTH <10 pg/ml on POD1 (p = 0.001). One patient in the ETBC group developed permanent hypoparathyroidism. Autotransplantation and inadvertent removal rates of parathyroid did not differ between the two groups. Although generally considered a safe method for patients with thyroid carcinoma, ETBC may increase the risk of transient hypoparathyroidism compared with conventional open surgery.

Impaired growth and intracranial calcifications in autosomal dominant hypocalcemia caused by a GNA11 mutation

OBJECTIVE

Autosomal dominant hypocalcemia (ADH) is characterized by hypocalcemia and inappropriately low PTH concentrations. ADH type 1 is caused by activating mutations in the calcium-sensing receptor (CASR), a G-protein-coupled receptor signaling through α11 (Gα11) and αq (Gαq) subunits. Heterozygous activating mutations in GNA11, the gene encoding Gα11, underlie ADH type 2. This study describes disease characteristics in a family with ADH caused by a gain-of-function mutation in GNA11.

DESIGN

A three-generation family with seven members (3 adults, 4 children) presenting with ADH.

METHODS

Biochemical parameters of calcium metabolism, clinical, genetic and brain imaging findings were analyzed.

RESULTS

Sanger sequencing revealed a heterozygous GNA11 missense mutation (c.1018G>A, p.V340M) in all seven hypocalcemic subjects, but not in the healthy family members (n=4). The adult patients showed clinical symptoms of hypocalcemia, while the children were asymptomatic. Plasma ionized calcium ranged from 0.95 to 1.14mmol/L, yet plasma PTH was inappropriately low for the degree of hypocalcemia. Serum 25OHD was normal. Despite hypocalcemia 1,25(OH)2D and urinary calcium excretion were inappropriately in the reference range. None of the patients had nephrocalcinosis. Two adults and one child (of the two MRI scanned children) had distinct intracranial calcifications. All affected subjects had short stature (height s.d. scores ranging from -3.4 to -2.3 vs -0.5 in the unaffected children).

CONCLUSIONS

The identified GNA11 mutation results in biochemical abnormalities typical for ADH. Additional features, including short stature and early intracranial calcifications, cosegregated with the mutation. These findings may indicate a wider role for Gα11 signaling besides calcium regulation.

Therapy of Hypoparathyroidism With PTH(1-84): A Prospective Six Year Investigation of Efficacy and Safety

CONTEXT

Human recombinant (rh)PTH(1-84) was recently approved for the treatment of refractory hypoparathyroidism, based upon a short-term phase 3 clinical trial. Long-term data are needed, because no time limit was placed on the treatment period.

OBJECTIVE

We studied the effect of long-term rhPTH(1-84) treatment in hypoparathyroidism for up to 6 years.

DESIGN

Prospective open-label study.

SETTING

Referral center.

PATIENTS

A total of 33 subjects with hypoparathyroidism.

INTERVENTIONS

rhPTH(1-84) treatment was initiated at a starting dose of 100 μg every other day for 6 years. Due to the availability of new dosages during the 6-year time period of the study, the dose could be and was adjusted for most patients to a daily dosing regimen.

MAIN OUTCOME MEASURES

Supplemental calcium and vitamin D requirements, serum and urinary calcium (monthly for 6 mo and then biannually), serum phosphorus, bone turnover markers, and bone mineral density (BMD) biannually.

RESULTS

Treatment with rhPTH(1-84) progressively reduced supplemental calcium requirements over 6 years by 53% (P < .0001) and 1,25-dihydroxyvitamin D requirements by 67% (P < .0001). Sixteen subjects (48%) were able to eliminate 1,25-dihydroxyvitamin D supplementation completely. Serum calcium concentration remained stable, and urinary calcium excretion fell. Lumbar spine BMD increased (3.8 ± 1%, P = .004) as did total hip BMD (2.4 ± 1%, P = .02), whereas femoral neck BMD remained stable and the distal one third radius decreased (-4.4 ±1%, P < .0001). Bone turnover markers increased significantly, reaching a 3-fold peak above baseline values at 1 year and subsequently declining but remaining higher than pretreatment values. Hypercalcemia was uncommon (12 episodes over 6 y; 2.5% of all values).

CONCLUSIONS

Long-term, continuous therapy of hypoparathyroidism for 6 years with rhPTH(1-84) is associated with reductions in supplemental calcium and calcitriol requirements, stable serum calcium concentration, and reduced urinary calcium excretion. The safety profile remains good. These data represent the longest experience with the therapeutic use of PTH for any condition and demonstrate its long-term efficacy and safety in hypoparathyroidism.

Management of Hypoparathyroidism: Present and Future

CONTEXT

Conventional management of hypoparathyroidism has focused upon maintaining the serum calcium with oral calcium and active vitamin D, often requiring high doses and giving rise to concerns about long-term consequences including renal and brain calcifications. Replacement therapy with PTH has recently become available. This paper summarizes the results of the findings and recommendations of the Working Group on Management of Hypoparathyroidism.

EVIDENCE ACQUISITION

Contributing authors reviewed the literature regarding physiology, pathophysiology, and nutritional aspects of hypoparathyroidism, management of acute hypocalcemia, clinical aspects of chronic management, and replacement therapy of hypoparathyroidism with PTH peptides. PubMed and other literature search engines were utilized.

EVIDENCE SYNTHESIS

Under normal circumstances, interactions between PTH and active vitamin D along with the dynamics of calcium and phosphorus absorption, renal tubular handing of those ions, and skeletal responsiveness help to maintain calcium homeostasis and skeletal health. In the absence of PTH, the gastrointestinal tract, kidneys, and skeleton are all affected, leading to hypocalcemia, hyperphosphatemia, reduced bone remodeling, and an inability to conserve filtered calcium. Acute hypocalcemia can be a medical emergency presenting with neuromuscular irritability. The recent availability of recombinant human PTH (1-84) has given hope that management of hypoparathyroidism with the missing hormone in this disorder will provide better control and reduced needs for calcium and vitamin D.

CONCLUSIONS

Hypoparathyroidism is associated with abnormal calcium and skeletal homeostasis. Control with calcium and active vitamin D can be a challenge. The availability of PTH (1-84) replacement therapy may usher new opportunities for better control with reduced supplementation requirements.

Parathyroid Hormone Replacement Therapy in Hypoparathyroidism: A Meta-Analysis

This study investigated the effect of human parathyroid hormone replacement therapy on specific disease-related outcomes in patients with hypoparathyroidism. Medline, Cochrane, EMBASE, and Google Scholar databases were searched until January 13, 2015 for randomized trials using the following search terms: hypoparathyroidism, parathyroid hormone/PTH, and hormone replacement therapy. Five randomized controlled trials (n=245) that investigated effect of either PTH (1-34) (3 trials) or PTH (1-84) (2 trials) on serum calcium, phosphate, 1, 25-dihydroxyvitamin D, 25-dihydroxyvitamin D levels, and urine level of calcium were included in the meta-analysis. Both PTH (1-34) and PTH (1-84) therapies were not associated with change in serum calcium level compared with calcitriol/placebo. The level of 24-h urine calcium excretion had a significant decrease in PTH (1-34)-treated group compared placebo/calcitriol (control) group (p≤0.012). PTH (1-34) did not change serum phosphate (p=0.053). PTH (1-84) did not change level of 24-h urine calcium excretion compared with control (p≥0.214) but it did decrease the levels of serum phosphorous (p=0.000). Both PTH-replacement therapies were not associated with change in serum 1,25-dihydroxyvitamin D level compared with control (p≥0.606), but were associated with a significant decrease in serum 25-dihydroxyvitamin D levels (p≤0.04). In conclusion, although the number of randomized trial is limited, our meta-analysis suggests that PTH (1-34) replacement therapy may maintain the serum calcium levels in the normal range by reducing the levels of urine calcium excretion, and both replacement therapies may maintain 1,25-dihydroxyvitamin D serum levels by reducing serum level of 25-dihydroxyvitamin D.

Hypercalcemia due to Milk-Alkali Syndrome and Fracture-Induced Immobilization in an Adolescent Boy with Hypoparathyroidism

BACKGROUND

Hypercalcemia of immobilization, while rare, may occur in adolescent boys after fracture. Although not fully understood, the mechanism appears to be related to bone turnover uncoupling, in part mediated by upregulation of RANKL. Animal studies suggest that parathyroidectomy suppresses RANKL-stimulated osteoclastogenesis in immobilized bone. Thus, immobilization-induced hypercalcemia should be uncommon in patients with hypoparathyroidism.

METHODS/RESULTS

We present a 15-year-old boy with well-controlled hypoparathyroidism who developed hypercalcemia and milk-alkali syndrome 5 weeks after sustaining a severe tibia/fibula fracture requiring bedrest. Milk-alkali syndrome (hypercalcemia, alkalosis, and renal insufficiency) results from chronic excessive ingestion of calcium and absorbable alkali. Prior to fracture, our patient had not experienced hypercalcemia despite high doses of supplements, necessary during puberty. Supplements were discontinued and his biochemistries normalized with saline diuresis and a dose of pamidronate. Alkaline phosphatase, which was low at presentation, returned to normal 5 weeks later with remobilization.

CONCLUSIONS

Fracture and immobilization caused acute suppression of bone formation with persistent bone resorption in this rapidly growing adolescent; continuation of carbonate-containing calcium supplements resulted in the milk-alkali syndrome. Therefore, close monitoring of serum calcium with adjustments in supplementation are indicated in immobilized patients with hypoparathyroidism. © 2016 S. Karger AG, Basel.