Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines from the Second International Workshop

Chapter 14: Post surgical follow-up of primary hyperparathyroidism

Primary hyperparathyroidism is treated surgically. Postoperatively, close monitoring of blood calcium levels is necessary to detect any hypocalcemia. Postoperative PTH assays can be performed within 24hours to identify patients who will not develop permanent hypoparathyroidism. Hypocalcemia may be caused by hypoparathyroidism (especially in the case of multi-glandular surgery or revision surgery) or by hungry bone syndrome. The latter should be suspected in case of major skeletal damage or severe preoperative vitamin D deficiency. It leads to severe hypocalcemia with normal or elevated PTH concentration, hypophosphatemia, hypomagnesemia, and low calciuria despite high doses of calcium and 1-25 OH vitamin D. Treatment of postoperative hypocalcemia depends on severity, symptoms and surgical procedure. In uni-glandular surgery, symptomatic treatment with calcium alone is recommended (0.5 to 1g/day). In multi-glandular involvement or repeat surgery, treatment with calcium (1 to 3g/day) is recommended if hypocalcemia is symptomatic or profound (<1.9mmol/L) (i.e. 76mg/L). If it is insufficient, the potential contribution of active vitamin D treatment should be assessed with an endocrinologist. If hypocalcemia is treated, patients should preferably be monitored by an endocrinologist (blood calcium level, calciuria and possibly phosphatemia and PTH). Under medical treatment of hypoparathyroidism, blood calcium levels should be monitored at least every 3 months for the first year, then at least twice a year.

mPatch: A Wearable Hydrogel Microneedle Patch for In Vivo Optical Sensing of Calcium

This study presents an in vivo optical hydrogel microneedle platform that measures levels of analytes in interstitial fluid. The platform builds on a previously published technique for molding hydrogel microneedles by developing a composite hydrogel (i.e., PEGDA and polyacrylamide) that is sufficiently stiff to penetrate skin in the hydrated state and whose fluorescence changes dynamically-via a conjugated aptamer-depending on level of analyte. In a demonstration relevant to hypercalcemia, the hydrogel microneedle distinguished varying concentrations of calcium (within a range of 0 to 2 mM, which spans physiologically meaningful variations for hypoparathyroidism) within 10 minutes. In rats, a compact CMOS sensor measuring fluorescence from microneedles distinguished low hypercalcemic (1.7 mM) from high hypercalcemic (2.3 mM) ionized calcium levels as determined from reference blood measurements. Overall, this work demonstrates in vivo feasibility of a concept-which we call mPatch-for an optical hydrogel microneedle to measure small changes in levels of analytes in interstitial fluid, which does not rely on extraction of interstitial fluid out of the dermis.

Permanent hypoparathyroidism following total thyroidectomy - Incidence and preventative strategies without imaging adjuncts

INTRODUCTION

Permanent hypoparathyroidism (pHypoPT) is the most common permanent complication of total thyroidectomy. We aim to describe the incidence and predictors of hypoparathyroidism in a consecutive series of patients treated in a high-volume centre and define strategies to reduce the risk of pHypoPT.

METHODS

1182 patients who underwent total thyroidectomy between April 2018 and June 2022 were analyzed. Temporary hypoparathyroidism (tHypoPT) was defined as PTH <0.4 ​pmol/L (<4 ​pg/mL) at day one post-operatively, or clinical or biochemical evidence of hypocalcemia. pHypoPT was defined as an ongoing need for calcitriol supplementation to maintain normocalcemia at 12 months. Symptomatic tHypoPT (OR 43.97, p ​< ​0.001) and number of parathyroid glands in the operative specimen (OR 2.31, p ​= ​0.022) were also significantly associated with pHypoPT.

RESULTS

Biochemical tHypoPT occurred in 205 (17.4 ​%) patients whilst pHypoPT occurred in 6 (0.5 ​%) patients. On multivariate analysis, parathyroid auto-transplantation (PA) independently reduced the risk of pHypoPT (OR 0.04, p ​= ​0.004).

CONCLUSIONS

The risk of pHypoPT after total thyroidectomy is 0.5 ​% when performed by high-volume surgeons. PA represents an important technique that reduces the risk of pHypoPT.

Hypoparathyroidism: Similarities and differences between Western and Eastern countries

BACKGROUD

Hypoparathyroidism (hypoPT) is characterized by acute and chronic complications due to insufficient parathyroid hormone (PTH) production or action. Several management guidelines have been developed, but mostly based on evidence from Western countries. Data from Eastern countries have not been systematically compared with those from Western countries.

METHODS

Literatures regarding to the epidemiology, genetics, risk factors, clinical manifestations and therapies for hypoPT in Easten and Western countries, including China, South Korea, Japan, India, and USA, Canada, Italy, and etc., were searched through PubMed and CNKI. This review was officially endorsed by European Calcified Tissue Society (ECTS) board.

RESULTS

Postoperative hypoPT is the major form of hypoPT in both Western and Eastern countries. The genetic profiles and clinical features of hypoPT are similar in Eastern and Western countries. The most commonly used medications in Eastern countries are calcium and native vitamin D or active vitamin D analogues, similar to their Western counterparts. While PTH replacement therapy is not available and approved to use in most Eastern countries.

CONCLUSION

Physicians and surgeons should follow the guidelines on the management of thyroid nodules, taking more care of protecting parathyroid glands during surgery. The cross-talk between East and West in the management of hypoPT should be continued. Direct comparisons of the management strategies in patients with hypoPT between Eastern and Wester countries regarding to the morbidity, mortality, quality of life, optimal dosage, efficacies and side-effects of conventional therapies or newer medications, as well as pharmacogenetics and pharmacoeconomics, would be valuable.

Case report: Prolonged and severe hungry bone syndrome after parathyroidectomy in X-linked hypophosphatemia

Tertiary hyperparathyroidism is characterized by hypercalcemia resulting from autonomous parathyroid hormone production and usually occurs after a prolonged period of secondary hyperparathyroidism. This condition can be a complication of X-linked hypophosphatemia (XLH), a rare genetic disease characterized by renal phosphate loss and consequent hypophosphatemia. Parathyroidectomy is considered the first-line therapy but surgical intervention can be complicated by hungry bone syndrome. A male Caucasian patient presented with XLH, diagnosed at the age of 3 years. At the age of 21, tertiary hyperparathyroidism occurred. Neck ultrasonography, neck magnetic resonance imaging, and 99Tc-sestamibi parathyroid scintigraphy revealed two hyperplastic parathyroid glands. To minimize the risk of hypercalcemia, calcimimetic therapy was initiated. After 6 months and preparation with 1,25-dihydroxy vitamin D, the patient underwent total parathyroidectomy with autotransplantation of half of a parathyroid gland into the sternocleidomastoid muscle. Histopathological examination revealed diffuse microscopical hyperplasia of the parathyroid glands. Despite oral supplementation with calcium carbonate and calcitriol, severe hypocalcemia developed on the second postoperative day, attributable to hungry bone syndrome. This finding was confirmed by an increase in bone turnover markers and a reduction in urinary calcium excretion. Hypocalcemia correction required continuous infusion of calcium gluconate for over 2 months. After approval, the patient began burosumab therapy with significant benefits. This case illustrates the complexity of treating tertiary hyperparathyroidism and mineral metabolism in patients with XLH. The hungry bone syndrome can complicate parathyroidectomy, exposing the patients to life-threatening risks. Burosumab therapy may reduce the risk of tertiary hyperparathyroidism developing in these patients.

Kenny-Caffey Syndrome Type 2 (KCS2): A New Case Report and Patient Follow-Up Optimization

Background/Objectives: Kenny-Caffey syndrome 2 (KCS2) is a rare cause of hypoparathyroidism, inherited in an autosomal dominant mode, resulting from pathogenic variants of the FAM111A gene, which is implicated in intracellular pathways regulating parathormone (PTH) synthesis and skeletal and parathyroid gland development. Methods: The case of a boy is reported, presenting with the characteristic and newly identified clinical, biochemical, radiological, and genetic abnormalities of KCS2. Results: The proband had noticeable dysmorphic features, and the closure of the anterior fontanel was delayed until the age of 4 years. Biochemical evaluation at several ages revealed persistent hypocalcemia, high normal phosphorous, and inappropriately low normal PTH. To exclude other causes of short stature, the diagnostic approach revealed low levels of IGF-1, and on CNS MRI, small pituitary gland and empty sella. Nocturnal levels of growth hormone were normal. MRI also revealed bilateral symmetrical microphthalmia and torturous optic nerves. Skeletal survey was compatible with cortical thickening and medullary stenosis of the long bones. Genomic data analysis revealed a well-known pathogenic variant of the FAM111A gene (c.1706G>A, p. R569H), which is linked with KCS2 or nanophthalmos. Conclusions: KCS2, although a rare disease, should be included in the differential diagnosis of hypoparathyroidism and short stature. Understanding the association of pathogenic variants with KCS2 phenotypic variability will allow the advancement of clinical genetics and personalized long-term follow-up and will offer insights into the role of the FAM111A gene in the disease pathogenesis and normal embryogenesis of implicated tissues and organs.

Up-to-Date Imaging for Parathyroid Tumor Localization in MEN1 Patients with Primary Hyperparathyroidism: When and Which Ones (A Narrative Pictorial Review)

Patients diagnosed with multiple endocrine neoplasia type-1 (MEN1) often initially present with primary hyperparathyroidism (pHPT), and typically undergo surgical intervention. While laboratory tests are fundamental for diagnosis, imaging is crucial for localizing pathological parathyroids to aid in precise surgical planning. In this pictorial review, we will begin by comprehensively examining key imaging techniques and their established protocols, evaluating their effectiveness in detecting abnormal parathyroid glands. This analysis will emphasize both the advantages and potential limitations within the clinical context of MEN1 patients. Additionally, we will explore integrated imaging approaches that combine multiple modalities to enhance localization accuracy and optimize surgical planning-an essential component of holistic management in MEN1 cases. Various imaging techniques are employed for presurgical localization, including ultrasound (US), multiphase parathyroid computed tomography (CT) scanning (4D CT), magnetic resonance imaging (MRI), and nuclear medicine techniques like single photon emission computed tomography/CT (SPECT/CT) and positron emission tomography/CT (PET/CT). US is non-invasive, readily available, and provides high spatial resolution. However, it is operator-dependent and may have limitations in certain cases, such as intrathyroidal locations, the presence of bulky goiters, thyroid nodules, and previous thyroidectomy. Four-dimensional CT offers dynamic imaging, aiding in the identification of enlarged parathyroid glands, particularly in cases of ectopic or supernumerary glands. Despite concerns about radiation exposure, efforts are underway to optimize protocols and reduce doses, including the use of dual-energy CT. MR imaging offers excellent soft tissue contrast without radiation exposure, potentially providing superior differentiation between parathyroid glands and the surrounding structures. Radionuclide imaging, especially PET/CT using radiopharmaceuticals like [18F]FCH, shows promising results in localizing parathyroid tumors, particularly in patients with MEN1. [18F]FCH PET/CT demonstrates high sensitivity and may provide additional information compared to other imaging modalities, especially in cases of recurrent HPT.

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.

Personalized parathyroid hormone therapy for hypoparathyroidism: Insights from pharmacokinetic-pharmacodynamic modelling

AIMS

A 42-year-old male developed chronic primary hypoparathyroidism after total thyroidectomy. Conventional therapy led to recurrent nephrolithiasis and therefore rhPTH(1-84) (parathyroid hormone [PTH]) treatment was considered. According to the dosing guideline for PTH, calcium plasma levels are adequately controlled with once-daily administration. However, the effect on urinary calcium excretion is only transient and hence does not lower the risk of nephrolithiasis. This raises the question of whether multiple-daily or continuous administration of PTH is more effective in lowering urinary calcium excretion. We aimed to construct a pharmacokinetic-pharmacodynamic (PKPD) model to answer this question.

METHODS

A single patient was treated with intermittent PTH followed by off-label continuous infusion of PTH. PTH was measured in plasma, calcium and phosphate in plasma and urine. A one-compartment PKPD model for PTH was developed with Edsim++. The effect of PTH was described by the relative clearance of calcium and phosphate.

RESULTS

The PKPD model for PTH showed visually a marked effect on phosphate clearance, but less on calcium clearance. During the study, the patient also received medication that influenced calcium homeostasis but to a lesser extent phosphate homeostasis. Therefore, phosphate was chosen as the effect parameter, resulting in an EC50 of 6.3 pmol/L PTH.

CONCLUSIONS

The PKPD model for PTH was completed with the unique data of a single patient who received PTH according to various dosing regimens, including continuous infusion. Continuous administration of PTH is favoured because it permanently increases the phosphate clearance and therefore needs to be further investigated.

Phenotype of patients with late diagnosis of 22q11 deletion: a review and retrospective study

BACKGROUND

Chromosome 22q11.2 deletion syndrome (22q11DS) is the most common microdeletion syndrome, typically presenting in neonates with congenital cardiac anomalies, hypocalcaemia and thymic hypoplasia. Some patients are diagnosed later in adolescence and adulthood, with less known about the clinical phenotype of these patients.

AIM

To summarise key clinical features in cases of 22q11DS diagnosed during adolescence and adulthood.

METHODS

This is a retrospective cohort study of 22q11DS patients diagnosed after 13 years of age over 2010-2021, with a literature review of published cases highlighting other late diagnoses. The study was performed in a large multicentre tertiary health network in Melbourne, Australia. Patients diagnosed with 22q11DS after the age of 13 years were included in the study. Main outcome measures were key clinical features in cases of late diagnosis of 22q11DS.

RESULTS

A literature search yielded 53 published case reports and one cohort study for review (62 subjects). Additionally, 10 cases of late diagnosis of 22q11DS were identified through a retrospective electronic medical chart review. Findings suggest that intellectual disability and learning difficulties, hypocalcaemia with hypoparathyroidism and facial dysmorphism remain key features in patients with a late diagnosis of 22q11DS, with hypocalcaemia being the most common presentation leading to diagnosis. Patients diagnosed in adulthood may lack classical clinical features of congenital cardiac anomalies and thymic hypoplasia. Immunological consequences of 22q11DS are also an important late-onset consideration. Atypical features may include basal ganglia calcification.

CONCLUSIONS

Chromosome 22q11DS has diverse clinical features and a highly variable phenotype, likely contributing to underdiagnosis and later diagnoses.

Management of autosomal dominant hypocalcemia type 1: Literature review and clinical practice recommendations

PURPOSE

Autosomal Dominant Hypocalcemia type 1 (ADH1), caused by gain-of-function variants in the calcium-sensing receptor (CASR), is characterized by a variable degree of hypocalcemia and hypercalciuria with inappropriately low PTH. The clinical spectrum is broad, ranging from being asymptomatic to presenting with severe clinical features of hypocalcemia and end-organ damage such as nephrolithiasis and intracerebral calcifications. Although the underlying pathophysiology is different, ADH1 patients are often managed as patients with 'classical' primary hypoparathyroidism, possibly leading to (exacerbation of) hypercalciuria. New treatments such as PTH analogues and calcilytics directly targeting the CASR are in the pipeline. Specific clinical guidance for treatment and monitoring of ADH1 patients is lacking. The purpose of this study is to provide a literature review on management of ADH1, including new therapies, and to formulate practice recommendations.

METHODS

We searched for articles and ongoing clinical trials regarding management of ADH1.

RESULTS

Forty articles were included. First we review the conventional treatment of ADH1, focusing on active vitamin D, calcium supplements, thiazide diuretics, phosphorus binders and dietary recommendations. In a second part we give an overview of studies with emerging treatments in ADH1: PTH analogues (PTH1-34, rhPTH1-84, TransCon PTH and others) and calcilytics (preclinical studies and clinical trials). In a third part we discuss literature findings regarding monitoring of ADH1 patients. Finally, we formulate clinical practice recommendations.

CONCLUSION

We provide an overview of conventional and new treatments for ADH1 patients. Based on these data, we propose practical recommendations to assist clinicians in the management of ADH1 patients.

[Albumin adjustment of total serum calcium - is it worth doing?]

Calcium is the most abundant mineral in the human body. About 99% of calcium is deposited in the bones in the form of hydroxyapatite and only 1% is located in the intracellular and extracellular fluid. Ionized calcium, which makes up about 50% of the total amount of circulating calcium, is biologically active; the remaining percentage is bound to plasma proteins (40%, of which albumin accounts for 90%, and globulins for 10%), or is in complex with anions (10%) such as citrate, lactate, bicarbonate, phosphate. Hypo- and hypercalcemia are common conditions treated by physicians of various specialities. Primary hyperparathyroidism and malignant tumors are the most common causes of hypercalcemia, whereas hypocalcemia is most often caused by hypoparathyroidism, malabsorption, vitamin D deficiency or chronic kidney disease. The interpretation of blood calcium concentration results affects the correct diagnosis, the need for further examination, and the choice of treatment. Concentration of ionized calcium is considered a more accurate indicator of the true status of calcemia compared to the concentration of total calcium, but its measurement is difficult due to strict preanalytical and analytical requirements. In the mid-1970s, calcium adjustment equations appeared, which are widely used today. However, some studies have expressed doubts about the sufficient reliability and sensitivity of the corresponding adjustment formulas. The diagnostic accuracy of widely used correction formulas in some clinical situations is lower than the diagnostic accuracy of uncorrected total calcium. The review discusses the history of the formulas for correcting total calcium for albumin, the factors influencing the result of correction, as well as its suitability in various conditions.

Hypoparathyroidism with situs inversus totalis: A case report

BACKGROUND

Hypoparathyroidism (HP) is a rare endocrine disorder, while situs inversus totalis (SIT) is a rare condition in which the internal organs are positioned in a mirrored pattern compared to their usual positions. This case illustrates some potential shared mechanisms between HP and SIT, highlighting the importance of accurate identification and prompt first emergency, offering insights for future research.

CASE SUMMARY

This report discusses a case of a middle-aged patient with adolescent-onset HP with concurrent SIT. The patient experienced recurrent episodes of increased neuromuscular excitability (manifesting as spasms in the hands and feet and laryngospasms) and even periods of unconsciousness. Initially, these symptoms led to a misdiagnosis of epilepsy. Nevertheless, upon thorough examination and treatment in the general medicine ward, the correct diagnosis was established. Corresponding treatment resulted in improved management of the patient's symptoms.

CONCLUSION

Co-occurrence of HP and SIT may be associated with genetic mutations, chromosomal anomalies, or hereditary factors, as may other similar conditions.

Incidence of transient and chronic hypoparathyroidism after total thyroidectomy - the experience of a tertiary center

BACKGROUND

The most common cause of hypoparathyroidism (hypoPT) in adults is iatrogenic due to total thyroidectomy, while the ideal moment for considering it chronic is still under debate. Our study aims at reporting the prevalence of transient and permanent hypoPT following thyroid surgery in a tertiary surgical center, as well as serum Parathormone (PTH) variation up to 12 months after surgery stratified according to the type of thyroid disease.

MATERIAL AND METHODS

519 patients who underwent total thyroidectomy in a tertiary surgical center from 2018 to 2023 were analyzed. Postoperative hypoPT was defined as low PTH (less than 15 pg/ml) and/or hypocalcemia (albumin-corrected levels less than 8.5 mg/dl) on day 1 after surgery. Patients were considered to have permanent hypoPT if they had not recovered completely within 1 year after total thyroidectomy. PTH levels were compared according to the underlying thyroid disease.

RESULTS

140 patients (26.97%) had postoperative hypoPT. Twenty-two patients (4.23%) were considered to have permanent hypoPT 12 months after surgery. Approximately half of the patients recovered between 3 months and 12 months after surgery. HypoPT thyroiditis patients had higher PTH levels 3 months after surgery compared to papillary/follicular cancer and multinodular goiter, respectively, and all recovered 1 year after surgery. Papillary/follicular carcinoma was associated with a 29.4% rate of transient and 8.5% rate of chronic hypoPT, respectively.

CONCLUSION

Most patients without incidental parathyroidectomy that still develop postoperative hypoPT will eventually recover; nevertheless, it can take up to 1 year for full resolution. Measuring serum PTH 3 months postoperative may be of interest.

Prevalence of chronic postsurgical hypoparathyroidism not adequately controlled: an analysis of a nationwide cohort of 337 patients

Purpose

The identification of patients with chronic hypoparathyroidism who are adequately (AC) or not adequately controlled (NAC) has clinical interest, since poor disease control is related to complications and mortality. We aimed to assess the prevalence of NAC patients in a cohort of subjects with postsurgical hypoparathyroidism.

Methods

We performed a multicenter, retrospective, cohort study including patients from 16 Spanish hospitals with chronic hypoparathyroidism lasting ≥3 years. We analyzed disease control including biochemical profile and clinical wellness. For biochemical assessment we considered three criteria: criterion 1, normal serum calcium, phosphorus and calcium x phosphorus product; criterion 2, the above plus estimated glomerular filtration rate ≥60 ml/min/1.73 m2; and criterion 3, the above plus normal 24-hour urinary calcium excretion. A patient was considered AC if he or she met the biochemical criteria and was clinically well.

Results

We included 337 patients with postsurgical hypoparathyroidism (84.3% women, median age 45[36-56] years, median time of follow-up 8.9[6.0-13.0] years). The proportions of NAC patients with criteria 1, 2 and 3 were, respectively, 45.9%, 49.2% and 63.1%. Patients who had dyslipidemia at the time of diagnosis presented a significantly higher risk of NAC disease (criterion 3; OR 7.05[1.44-34.45]; P=0.016). NAC patients (criterion 2) had a higher proportion of subjects with incident chronic kidney disease and eye disorders, and NAC patients (criterion 3) had a higher proportion of incident chronic kidney disease, nephrolithiasis and dyslipidemia than AC patients.

Conclusion

The present study shows a strikingly high prevalence of NAC patients in the clinical practice of Spanish endocrinologists. Results suggest that NAC disease might be associated with some prevalent and incident comorbidities.

Long-term kidney outcomes in patients with permanent hypoparathyroidism after total thyroidectomy for benign disease: A population-based study

BACKGROUND

Permanent hypoparathyroidism is a significant complication after total thyroidectomy. This study aimed to evaluate the long-term impact of postoperative permanent hypoparathyroidism on kidney outcomes.

METHODS

Data of patients undergoing total thyroidectomy from 1999 to 2014 were retrieved. The estimated glomerular filtration rate was determined from serum creatinine results. Permanent hypoparathyroidism was defined as requiring oral calcium and vitamin D supplements postoperatively for at least 6 months. The primary outcome was a sustained decline in the estimated glomerular filtration rate from baseline by ≥50%. Secondary outcomes were end-stage kidney disease (a composite of sustained estimated glomerular filtration rate <15 mL/min/1.73 m2, need for dialysis, and kidney transplantation) and rate of estimated glomerular filtration rate decline. Patients with and without permanent hypoparathyroidism were compared. Multivariable Cox regression analysis was performed to identify independent risk factors for sustained estimated glomerular filtration rate decline by ≥50%.

RESULTS

In total, 3,245 patients were eligible for analysis; 418 patients (12.9%) had permanent hypoparathyroidism. Upon median follow-up of 11.6 years, more patients with permanent hypoparathyroidism had a sustained decline in estimated glomerular filtration rate from baseline by ≥50% compared to those without (15.6% vs 6.9%, P < .001). Similar findings were obtained on Kaplan-Meier analysis (P < .001). Permanent hypoparathyroidism was an independent risk factor for sustained estimated glomerular filtration rate decline by ≥50% (adjusted hazard ratio 2.77, P < .001). Other risk factors included age, preoperative estimated glomerular filtration rate <60 mL/min/1.73m2, and diabetes mellitus. Patients with permanent hypoparathyroidism had a more rapid estimated glomerular filtration rate decline (-1.60 vs -0.70 mL/min/1.73 m2/year, difference -0.91 mL/min/1.73m2/year, P < .001).

CONCLUSION

Patients with postsurgical permanent hypoparathyroidism were at greater risk of renal impairment. Further research is warranted to improve the identification and preservation of parathyroid glands during thyroidectomy to minimize patient morbidity.

New insights into the vitamin D/PTH axis in endocrine-driven metabolic bone diseases

BACKGROUND

Endocrine regulation of bone metabolisms is the focus of the "Skeletal Endocrinology" series of meetings.

AIMS

To report on the outcome of the discussion on the role of vitamin D/PTH axis in endocrine osteopathies held during the 10th Skeletal Endocrinology Meeting which took place in Stresa (Italy) in March 2023.

OUTCOMES

Vitamin D/PTH axis has relevant influence on several outcomes in the general population and in patients affected by endocrinopathies such as hypoparathyroidism and secreting pituitary adenomas.

CONCLUSIONS

Assessing the status of the vitamin D/PTH axis and using vitamin D and PTH as therapeutic agents is mandatory in several endocrine-related bone metabolic conditions.

Hypoparathyroidism: changes in brain structure, cognitive impairment, and reduced quality of life

Hypoparathyroidism (HypoPT) is a disease with no/or inadequate production/secretion of parathyroid hormone (PTH) from the parathyroid glands. Low levels of PTH result in hypocalcemia, which is often treated with calcium supplementation and active vitamin-D analogs. However, increasing evidence suggests that HypoPT has a profound impact on several organ systems. Quality of life (QOL) is reduced in patients with HypoPT, partly due to symptoms related to the central nervous system-including subjective feelings of confusion, a reduced ability to focus and think clearly (ie, "brain fog"). However, the extent to which these complex symptoms relate to quantifiable changes in patients' cognitive performance as determined by neuropsychological tests remains unclear. The brains of HypoPT patients may reveal tissue calcifications, but the extent to which long-term brain exposure to low PTH levels and/or changing calcium levels affects brain structure is unknown. In a cross-sectional study, we investigated PTH levels, QOL, cognitive impairment, and brain structure in well-treated post-surgical and non-surgical hypoparathyroid patients compared with healthy controls. QOL was quantified by the SF36v2, WHO-5 wellbeing Index, and two disease-specific questionnaires-the HPQ28 and Hypoparathyroidism Symptom Diary. Cognitive functions were tested using comprehensive neuropsychological. Brain structure was quantified by morphological analyses of magnetic resonance imaging images. We found reduced QOL and cognitive functioning in terms of processing speed, executive functions, visual memory, and auditory memory in HypoPT. Furthermore, HypoPT revealed a reduced volume of the hippocampus-and the size of the thalamus in postsurgical patients was associated with the disease duration. Importantly, patients reporting severe brain fog had a smaller hippocampus than those with less brainfog. HypoPT is associated with quantifiable cognitive deficits and changes in brain structure that align with patient symptoms. Our exploratory study warrants further studies of the neurobiological impact of PTH and of the impact of PTH replacements therapy on patients' cognitive functioning.

Hypoparathyroidism update

PURPOSE OF REVIEW

Since the release of the 2022 Second International Workshop Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines, updates and advances are now available in the cause, complications, and treatment of adult chronic hypoparathyroidism (hypoPTH). This review aims to highlight these new findings and implications to patient care.

RECENT FINDINGS

Postsurgical hypoparathyroidism remains the most common cause, immune-related hypoparathyroidism from checkpoint inhibitors is an emerging autoimmune cause. In a large retrospective cohort study of thyroidectomies, incident fracture was lower, particularly in the vertebra, in the hypoPTH cohort, compared with postthyroidectomy control group. Hypercalciuria increases risk for renal calculi in hypoPTH independent of disease duration and treatment dose. Quality of life is impaired in hypoPTH patients on conventional therapy, improvement was noted post-PTH replacement. TranCon PTH phase 3 RCT reported eucalcemia with reduced renal calcium excretion, normalization of bone turn-over markers, stable BMD and improved quality of life.

SUMMARY

HypoPTH is a chronic disease associated with significant morbidity and poor Quality of Life. Awareness of treatment targets and follow-up investigations can alleviate patient anxiety regarding over-treatment and under-treatment. Progress in long-acting PTH replacement strategies might provide accessible, feasible alternatives to conventional therapy in brittle hypoPTH patients.

Presentation of hypoparathyroidism in Italy: a nationwide register-based study

PURPOSE

We sought to assess the clinical presentation of hypoparathyroidism (HypoPT) in Italy.

METHODS

We performed a nationwide study retrieving data from the hospital discharge ICD-9 codes database of the Italian Health Ministry, from 2007 through 2017. The codes corresponding to diagnosis of cardiovascular disease, cancer, infection, renal failure, psychiatric disease, upper airway tract infection and pneumonia, seizures, nephrolithiasis, cognitive impairment, cerebral calcifications, skin disorders, fracture, and cataract were retrieved when associated with the diagnosis of HypoPT (252.1). We excluded codes corresponding to diagnoses of cancer of the neck region. In-hospital mortality rate was calculated. We retrieved the same data from an age- and sex-matched non-HypoPT control population.

RESULTS

Fourteen thousand five hundred seventy-nine hospitalizations for HypoPT and controls were analyzed. Hospitalization for cardiovascular disease, cancer, infection, renal failure, seizures, nephrolithiasis, cerebral calcifications (p < 0.0001), and cognitive impairment (p < 0.05) were more common in HypoPT compared to controls. Mean age of HypoPT with cardiovascular disease, cancer, and renal failure was younger compared to controls (p < 0.0001). The OR of hospitalization for cardiovascular disease, cancer, renal failure, seizures (OR 2, 40, 48  and 1.6, respectively), and nephrolithiasis (OR 1.6) were significant in HypoPT compared to non-HypoPT. The OR of hospitalization for infection and cognitive impairment were significant only in HypoPT women (OR 1.3 and 2.3, respectively). In-hospital mortality rate was lower in HypoPT vs controls (0.5% and 3.7%; p < 0.0001).

CONCLUSION

Hospitalizations for cardiovascular disease, cancer, and renal failure are more prevalent and occur at a younger age in HypoPT vs non-HypoPT. Hospitalizations for seizures and nephrolithiasis are frequent in HypoPT; those for infection and cognitive impairment are more common in HypoPT women.

Palopegteriparatide Treatment Improves Renal Function in Adults with Chronic Hypoparathyroidism: 1-Year Results from the Phase 3 PaTHway Trial

INTRODUCTION

Individuals with chronic hypoparathyroidism managed with conventional therapy (active vitamin D and calcium) have an increased risk for renal dysfunction versus age- and sex-matched controls. Treatments that replace the physiologic effects of parathyroid hormone (PTH) while reducing the need for conventional therapy may help prevent a decline in renal function in this population. This post hoc analysis examined the impact of palopegteriparatide treatment on renal function in adults with chronic hypoparathyroidism.

METHODS

PaTHway is a phase 3 trial of palopegteriparatide in adults with chronic hypoparathyroidism that included a randomized, double-blind, placebo-controlled 26-week period followed by an ongoing 156-week open-label extension (OLE) period. Changes in renal function over 52 weeks (26 weeks blinded + 26 weeks OLE) were assessed using estimated glomerular filtration rate (eGFR). A subgroup analysis was performed with participants stratified by baseline eGFR < 60 or ≥ 60 mL/min/1.73 m2.

RESULTS

At week 52, over 95% (78/82) of participants remained enrolled in the OLE and of those, 86% maintained normocalcemia and 95% achieved independence from conventional therapy (no active vitamin D and ≤ 600 mg/day of calcium), with none requiring active vitamin D. Treatment with palopegteriparatide over 52 weeks resulted in a mean (SD) increase in eGFR of 9.3 (11.7) mL/min/1.73 m2 from baseline (P < 0.0001) and 43% of participants had an increase ≥ 10 mL/min/1.73 m2. In participants with baseline eGFR < 60 mL/min/1.73 m2, 52 weeks of treatment with palopegteriparatide resulted in a mean (SD) increase of 11.5 (11.3) mL/min/1.73 m2 (P < 0.001). One case of nephrolithiasis was reported for a participant in the placebo group during blinded treatment; none were reported through week 52 with palopegteriparatide.

CONCLUSION

In this post hoc analysis of the PaTHway trial, palopegteriparatide treatment was associated with significantly improved eGFR at week 52 in addition to previously reported maintenance and normalization of serum and urine biochemistries. Further investigation of palopegteriparatide for the preservation of renal function in hypoparathyroidism is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04701203.

Long-term complications of permanent hypoparathyroidism in adults: prevalence and associated factors

INTRODUCTION

Patients with Chronic hypoparathyroidism (CHPT) receiving conventional treatment are exposed to several long-term complications including basal ganglia calcifications, posterior subcapsular cataract, kidney stones, and renal insufficiency. The aim of this study was to assess the prevalence and the associated factors of these complications in patients with CHPT.

METHODS

We conducted a cross-sectional study including 58 patients with CHPT. All participants underwent physical examination, biochemical assessment (total serum calcium, serum phosphorus, serum albumin, intact-PTH, serum magnesium, 25-hydroxy-vitamin D, serum creatinine, thyroid stimulating hormone (TSH), and 24-hour urinary calcium), slit lamp examination, brain computed tomography scan (CT-scan), and renal ultrasound.

RESULTS

Participants had a mean age of 52.6 ± 16.4 years and a gender ratio (women/men) of 3.5. Fahr syndrome, cataract, urolithiasis, and renal failure were found in 55%, 62%, 12%, and 17% of cases, respectively. CHPT duration >15 years (Adjusted-OR = 43.1, 95-CI: 2.63-703.06, p = 0.008) and poor adherence to treatment (Adjusted-OR = 8.04, 95%-CI: 1.52-42.42, p = 0.014) were independently associated with the risk of Fahr syndrome. Age >55 years (adjusted-OR = 5.07, 95-CI: 1.10-23.42, p = 0.037), disease duration >15 years (adjusted-OR = 20.21, 95-CI: 1.54-265.84, p = 0.022), and magnesium level <0.8 mmol/l (adjusted-OR = 36.46, 95-CI: 3.75-354.08, p = 0.002) were independently associated with the risk of subcapsular cataract. Only hypercalciuria (Adjusted-OR = 21.27, 95-CI: 2.31-195.91, p = 0.007) was an independent risk factor for kidney stones. Renal failure was not associated with kidney stones (p = 1). However, creatinine clearance was negatively correlated with age (r = -0.784; p < 10-3) and disease duration (r = -0.352; p = 0.007).

CONCLUSION

Our results revealed high prevalences of neurological, ocular, and renal complications in patients with CHPT and emphasized the importance of regular biological monitoring, therapeutic adjustments, screening, and adherence to treatment in the prevention of these complications.

Cost-Effectiveness of Parathyroid Cryopreservation and Autotransplantation

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposure

Parathyroid cryopreservation and DACP.

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

A delicate balance: the challenges of hypoparathyroidism

A 38-yr-old woman with chronic non-surgical hypoparathyroidism, managed elsewhere, presented to our practice with symptomatic hypocalcemia. At the age of 17, she began to suffer from muscle cramps, paresthesia, and ongoing diffuse pain. It took years before she was correctly diagnosed with hypoparathyroidism. Her symptoms were severe enough that she required emergency room visits several times a year. After she was properly diagnosed and started on calcium and calcitriol therapy, she continued to experience frequent episodes of severe hypocalcemia. She saw multiple healthcare providers who each introduced a new regimen. In addition, poor communication led to her discontinuing her medications altogether. As a result, her calcium levels remained consistently low, and she lost confidence in her prospect for better health. At the time of her visit to our clinic, she had discontinued calcitriol, was taking a large amount of oral calcium daily all at once, and had hypocalcemia. We addressed her concerns, and the challenges she faces with adherence to her medication regimen. We provided her with detailed information about the disease and the reasoning behind her treatment plan. Treatment was initiated with calcium carbonate 600 mg 3 times daily and calcitriol 0.5 mcg once daily. One week after treatment initiation, her test results showed improvement in her albumin-adjusted calcium, phosphorus, and 24-h urine calcium which were all within target range.

Impaired Quality of Life in Patients with Post-Surgical Hypoparathyroidism

BACKGROUND

Hypoparathyroidism is characterized by chronic hypocalcemia with low or abnormal parathyroid hormone levels. Thyroid surgery remains a predominant cause of hypoparathyroidism, often preventable by partial thyroidectomy. Although hypoparathyroidism can impair quality of life (QOL), data remain limited for Latin America. We aimed to characterize clinical manifestations and QOL in patients with postsurgical hypoparathyroidism.

METHODS

This case-control study included patients (>18 years) who underwent total thyroidectomy (TT) for differentiated thyroid cancer (DTC) with postsurgical hypoparathyroidism (Group 1, Cases) and those with DTC who underwent TT without postsurgical hypoparathyroidism (Group 2, Controls). Clinical records were collected, and the SF-36v2 QOL survey and a structured symptom survey were applied. A logistic multivariate regression analysis was performed.

RESULTS

This study included 106 subjects (Group 1, N=41; Group 2, N=65). Group 1 patients were younger, had a higher frequency of lymph node resection, and more frequently received Ι-131 than Group 2 patients (p<0.05). In the SF-36v2 survey, Group 1 had fewer physical-functioning scores (odds ratio, 3.8; 95% confidence interval, 1.2-11.7) and lower scores in mental and physical components than Group 2 and national records. Commonly reported symptoms include paresthesia, daily fatigue, and memory alterations. Treatment adherence rates were 56% and 71% for calcium and calcitriol, respectively. Furthermore, 24% of patients experienced one or more hypoparathyroidism drug-related adverse effects.

CONCLUSIONS

Patients with postsurgical hypoparathyroidism had an impaired QOL, a high frequency of disease-associated symptoms, and limited treatment adherence. These results should be considered when deciding the best surgical alternative for DTC.

Autofluorescence-Guided Total Thyroidectomy in Low-Volume, Nonparathyroid Institutions

Importance

Hypoparathyroidism following thyroid surgery is a serious complication that occurs frequently when surgery is performed by low-volume thyroid surgeons without experience in parathyroid surgery.

Objective

To evaluate the occurrence of hypoparathyroidism following total thyroidectomy after the introduction of autofluorescence in low-volume, nonparathyroid institutions.

Design, Setting, and Participants

This prospective, multicenter cohort study, with a follow-up period of up to 1 year, was conducted in Denmark at 2 low-volume nonparathyroid institutions between January 2021 and November 2023. All adult patients referred for total thyroidectomy were assessed for eligibility (n = 90). Only patients with no history of thyroid surgery were considered (n = 89). Patients who only underwent lobectomy (n = 6) or declined to participate (n = 5) were excluded. All included patients completed follow-up. The prospective cohort was compared with a historical cohort of successive patients undergoing primary total thyroidectomy from 2016 to 2020 (before autofluorescence was available).

Intervention

Included patients underwent autofluorescence-guided total thyroidectomy.

Main outcomes and Measures

Rate of hypoparathyroidism. Immediate hypoparathyroidism was defined as the need for active vitamin D postoperatively, whereas permanent hypoparathyroidism was considered when there still was a need for active vitamin D 1 year after surgery.

Results

Seventy-eight patients underwent autofluorescence-guided surgery (mean [SD] age, 55.6 [13.1] years; 67 [86%] female) and were compared with 89 patients in the historical cohort (mean [SD] age, 49.7 [12.8] years; 78 [88%] female). The rate of immediate hypoparathyroidism decreased from 37% (95% CI, 27%-48%) to 19% (95% CI, 11%-30%) after the introduction of autofluorescence (P = .02). Permanent hypoparathyroidism rates decreased from 32% (95% CI, 22%-42%) to 6% (95% CI, 2%-14%) (P < .001), reaching 0% at the end of the study. More parathyroid glands were identified with autofluorescence (75% [95% CI, 70%-80%] vs 61% [95% CI, 56%-66%]) (P < .001) and less parathyroid glands were inadvertently excised (4% [95% CI, 1%-11%] vs 21% [95% CI, 13%-31%]) (P = .001).

Conclusions and Relevance

In this cohort study of autofluorescence-guided thyroid surgery in low-volume, nonparathyroid institutions, the use of autofluorescence was associated with a significant decrease in both immediate and permanent hypoparathyroidism. When autofluorescence was used, hypoparathyroidism rates were comparable with those of high-volume surgeons who also perform parathyroid surgery.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Hypoparathyroidism and mortality after total thyroidectomy: A nationwide matched cohort study

OBJECTIVE

Total thyroidectomy (TT) carries a risk of hypoparathyroidism (hypoPT). Recently, hypoPT has been associated with higher overall mortality rates. We aimed to evaluate the frequency of hypoPT and mortality in patients undergoing TT in Denmark covering 20 years.

DESIGN

Retrospective Cohort study.

PATIENTS AND MEASUREMENTS

Using population-based registries, we identified all Danish individuals who had undergone TT between January 1998 and December 2017. We included a comparison cohort by randomly selecting 10 citizens for each patient, matched on sex and birth year. HypoPT was defined as treatment with active vitamin D after 12 months postoperatively. We used cumulative incidence to calculate risks and Cox regression to compare the rate of mortality between patients and the comparison cohort. We evaluated patients in different comorbidity groups using the Charlson Comorbidity Index and by different indications for surgery.

RESULTS

7912 patients underwent TT in the period. The prevalence of hypoPT in the study period was 16.6%, 12 months postoperatively. After adjusting for potential confounders the risk of death due to any causes (hazard ratio; 95% confidence intervals) following TT was significantly increased (1.34; 1.15-1.56) for patients who developed hypoPT. However, subgroup analysis revealed mortality was only increased in malignancy cases (2.48; 1.99-3.10) whereas mortality was not increased when surgery was due to benign indications such as goitre (0.88; 0.68-1.15) or thyrotoxicosis (0.86; 0.57-1.28).

CONCLUSIONS

The use of active vitamin D for hypoPT was prevalent one year after TT. Patients with hypoPT did not have an increased risk of mortality following TT unless the indication was due to malignancy.

Continuous Subcutaneous Delivery of rhPTH(1-84) and rhPTH(1-34) by Pump in Adults With Hypoparathyroidism

Context

Continuous subcutaneous infusion of recombinant parathyroid hormone (rhPTH) through a pump has been proposed as a therapeutic alternative for patients with chronic hypoparathyroidism who remain symptomatic or hypercalciuric on conventional treatment (calcium and active vitamin D) or daily injections of rhPTH(1-84) or rhPTH(1-34). However, the real-world evidence of the outcome of this novel therapy is limited.

Case Descriptions

We report the clinical and biochemical outcomes of 12 adults with hypoparathyroidism (11 women, age 30-70 years, and 1 man, age 30 years) from 3 different clinical sites in the United States who were transitioned from conventional therapy to daily injections of rhPTH(1-84) or rhPTH(1-34) and then switched to continuous administration of rhPTH(1-84)/rhPTH(1-34) via pump therapy. In most patients, mean serum calcium concentrations increased while on PTH pump therapy compared with both conventional therapy (in 11 patients) and single/multiple daily rhPTH injections (in 8 patients). Despite this, 10 patients had lower median 24-hour urinary calcium levels while on PTH pump therapy compared with prior therapy (mean ± SD difference: -130 ± 222 mg/24 hours). All patients reported a qualitative decrease in hypocalcemic symptoms while receiving pump therapy. Three patients had pod failure at least once, and 1 patient developed an infusion site reaction.

Conclusion

In this case series of 12 patients with chronic hypoparathyroidism treated with rhPTH(1-84)/rhPTH(1-34) administered via a pump, improvement in clinical and biochemical parameters were observed in the majority of the patients. Our observations indicate benefits of pump administration of rhPTH that warrant further investigation.

Features of patients and fracture risk in hypoparathyroidism; a single center study

PURPOSE

Patients with hypoparathyroidism (hypoPT) have low bone turnover and high bone mineral density (BMD). However, data on fracture risk are conflicting. The objectives of this study were: 1. To describe clinical/biochemical characteristics of hypoPT patients followed at a single medical center. 2. To identify postsurgical hypoPT patients and investigate their fracture rate compared with gender/age-matched post-surgical normocalcemic patients.

METHODS

Retrospective analysis of patient's medical records treated at the tertiary medical center in 2010-2021 identified by computerized medical database search.

RESULTS

The cohort included 133 patients (91% women, mean age 64 ± 13 years) of whom 105 (79%) had post-thyroidectomy hypoparathyroidism and the remainder had an autoimmune/idiopathic/other etiology. Mean follow-up time was 21 ± 12 and 27 ± 12 years, respectively. The control group included 142 post-thyroidectomy patients without hypoparathyroidism. Patients in the postsurgical hypoparathyroidism group were older and had higher calcium and PTH levels at diagnosis than the non-surgical hypoPT patients. Comparing the postsurgical hypoPT and postsurgical normocalcemic control patients revealed a significantly higher BMD in the hypoPT group. Yet, fracture rates were 31% in the postsurgical hypoparathyroidism group and 21% in the control group (P = 0.1) over a similar median follow-up period (17 and 18.4 years, respectively). In both groups the most common fracture site was the spine (50% and 70%, respectively; p = 0.33), mainly nonclinical morphometric fractures. Higher phosphorus blood level was associated with increased fracture risk.

CONCLUSIONS

The relatively high BMD in patients with postsurgical hypoparathyroidism is not associated with lower fracture risk. Silent morphometric fractures are quite common in this group of patients.

Recalcitrant Hypocalcemia: Postsurgical Hypoparathyroidism Exacerbated by a Chyle Leak Treated With Octreotide

Background/Objective

To report a case of recalcitrant post-surgical hypocalcemia caused by hypoparathyroidism complicated by a chyle leak and octreotide use.

Case Report

A man in his 60s with a 4-month history of voice changes, 10-pound weight loss, and a right-sided neck mass presented with difficulty breathing for 1 week. He had a right laryngeal/hypopharyngeal mass, which was biopsied. Pathology results were positive for invasive squamous cell carcinoma. He underwent an extensive neck surgery, including total thyroidectomy. Postsurgical laboratory results revealed serum corrected calcium of 7.6 mg/dL (ref 8.0-10.2 mg/dL) and parathyroid hormone <6.3 pg/mL (ref. 10-65). Despite treatment with calcium carbonate 12 g (elemental) daily, calcitriol and hydrochlorothiazide, his corrected serum calcium levels remained low. Patient also had a chyle leak that was treated with octreotide. Resolution of his hypocalcemia occurred after substitution of calcium carbonate with calcium citrate, cessation of octreotide, and management of the chyle leak.

Discussion

Our patient likely developed recalcitrant hypocalcemia from: 1) postsurgical hypoparathyroidism, 2) a chyle leak, and 3) the use of octreotide. Administration of octreotide to seal the chyle leak most likely decreased gastric acid production and contributed to decrease in absorption of calcium carbonate. Oral calcium citrate may be better absorbed in this case.

Conclusion

Postsurgical hypoparathyroidism can lead to hypocalcemia. This case is unique in that the patient's chyle leak and the use of octreotide contributed to recalcitrant hypocalcemia.

Open-label extension of a randomized trial investigating safety and efficacy of rhPTH(1-84) in hypoparathyroidism

Hypoparathyroidism (HypoPT) is a rare disease, often inadequately controlled by conventional treatment. PARALLAX was a mandatory post-marketing trial assessing pharmacokinetics and pharmacodynamics of different dosing regimens of recombinant human parathyroid hormone 1-84 (rhPTH[1-84]) for treating HypoPT. The present study (NCT03364738) was a phase 4, 1-yr open-label extension of PARALLAX. Patients received only 2 doses of rhPTH(1-84) in PARALLAX and were considered treatment-naive at the start of the current study. rhPTH(1-84) was initiated at 50 μg once daily, with doses adjusted based on albumin-corrected serum calcium levels. Albumin-corrected serum calcium (primary outcome measure), health-related quality of life (HRQoL), adverse events, and healthcare resource utilization (HCRU) were assessed. The mean age of the 22 patients included was 50.0 yr; 81.8% were women, and 90.9% were White. By the end of treatment (EOT), 95.5% of patients had albumin-corrected serum calcium values in the protocol-defined range of 1.88 mmol/L to the upper limit of normal. Serum phosphorus was within the healthy range, and albumin-corrected serum calcium-phosphorus product was below the upper healthy limit throughout, while mean 24-h urine calcium excretion decreased from baseline to EOT. Mean supplemental doses of calcium and active vitamin D were reduced from baseline to EOT (2402-855 mg/d and 0.8-0.2 μg/d, respectively). Mean serum bone turnover markers, bone-specific alkaline phosphatase, osteocalcin, procollagen type I N-terminal propeptide, and type I collagen C-telopeptide increased 2-5 fold from baseline to EOT. The HCRU, disease-related symptoms and impact on HRQoL improved numerically between baseline and EOT. Nine patients (40.9%) experienced treatment-related adverse events; no deaths were reported. Treatment with rhPTH(1-84) once daily for 1 yr improved HRQoL, maintained eucalcemia in 95% of patients, normalized serum phosphorus, and decreased urine calcium excretion. The effects observed on urine calcium and the safety profile are consistent with previous findings.

Clinical trial identifier

NCT03364738.

Incident comorbidities in patients with chronic hypoparathyroidism after thyroidectomy: a multicenter nationwide study

Purpose

Population-based and registry studies have shown that chronic hypoparathyroidism is accompanied by long-term complications. We aimed to evaluate the risk of incident comorbidity among patients with chronic postsurgical hypoparathyroidism in real-life clinical practice in Spain.

Methods

We performed a multicenter, retrospective cohort study including patients with chronic postsurgical hypoparathyroidism lasting ≥3 years with at least a follow-up visit between January 1, 2022 and September 15, 2023 (group H). The prevalence and incidence of chronic complications including chronic kidney disease, nephrolithiasis/nephrocalcinosis, hypertension, dyslipidemia, diabetes, cardiovascular disease, central nervous system disease, mental health disorders, eye disorders, bone mineral density alterations, fracture and cancer were evaluated. Patient data were compared with a group of patients who did not develop hypoparathyroidism, matched by gender, age, and follow-up time after thyroidectomy (group NH).

Results

We included 337 patients in group H (median [IQR] age, 45 [36-56] years; median time of follow-up, 8.9 [6.0-13.0] years; women, 84.3%) and 669 in group NH (median age, 47 [37-55] years; median time of follow-up, 8.0 [5.3-12.0] years; women, 84.9%). No significant differences were found in the prevalence of comorbidities at the time of thyroidectomy between both groups. In multivariable adjusted analysis, patients with chronic hypoparathyroidism had significantly higher risk of incident chronic kidney disease (OR, 3.45; 95% CI, 1.72-6.91; P<0.001), nephrolithiasis (OR, 3.34; 95% CI, 1.55-7.22; P=0.002), and cardiovascular disease (OR, 2.03; 95% CI, 1.14-3.60; P=0.016), compared with patients without hypoparathyroidism. On the contrary, the risk of fracture was decreased in patients with hypoparathyroidism (OR, 0.09; 95% CI, 0.01-0.70; P=0.021).

Conclusion

This study demonstrates that, in the clinical practice of Spanish endocrinologists, a significant increase in the risk of chronic kidney disease, nephrolithiasis and cardiovascular disease, as well as a reduction in the risk of fractures is detected. These results are of interest for the development of new clinical guidelines and monitoring protocols for patients with hypoparathyroidism.

Performance in Behavioral Testing in an Animal Model of Post-Surgical Hypoparathyroidism

BACKGROUND

Hypoparathyroidism (HypoPT) is characterized by hypocalcemia and undetectable/inappropriately low PTH. Post-surgical HypoPT (PS-HypoPT) is the most common cause. Patients with PS-HypoPT present neuropsychological symptoms, probably due to the PTH deprivation in the central nervous system (CNS). However, these mechanisms are still not elucidated. The aim of this study was to evaluate the effects of PTH deprivation on CNS in an animal model of PS-HypoPT via a cognitive/behavioral assessment approach.

METHODS

A surgical rat model of PS-HypoPT was obtained and treated with calcium to maintain normocalcemia. Twenty PS-HypoPT rats and twenty sham-operated controls (Crl) underwent behavioral testing in a Morris Water Maze (MWM), Open Field (OF), and Elevated Plus Maze (EPM).

RESULTS

In the MWM, PTx rats showed a higher Escape Latency Time compared to Crl rats (p < 0.05); we observed a statistically significant improvement in the performance (day 1 to 8 p < 0.001), which was less pronounced in PTx group. In the OF test, the time and distance spent in the zone of interest were significantly lower in the PTx group compared with the Crl (p < 0.01 and p < 0.01). In the EPM experiment, the time spent in the close arm was significantly higher in the PTx group compared with the Crl (p < 0.01).

CONCLUSIONS

This animal model of PS-HypoPT shows an impairment in spatial memory, which improved after training, and a marked anxiety-like behavior, resembling the condition of patients with PS-HypoPT. Further studies are needed to elucidate mechanisms.

Hypoparathyroidism following total thyroidectomy: high rates at a low-volume, non-parathyroid institution

Background

Hypoparathyroidism following total thyroidectomy is globally the most common complication to thyroid surgery. The reported complication rates vary widely and might be highly dependent on the surgical experience. In this study we aimed to evaluate the rate of hypoparathyroidism following primary total thyroidectomy at a low-volume institution that only performs thyroid surgery and does not have any experience with parathyroid surgery.

Methods

Retrospective cohort study. All patients undergoing primary total thyroidectomy at the ENT-Department, Goedstrup Hospital, Denmark, over a 5-year period (2016-2020) were identified through the procedure codes for total thyroidectomy. Medical records, pathology reports, biochemical and medical histories were fully assessed for each patient. The primary endpoint was the rate of hypoparathyroidism- both immediate and permanent. Secondary outcomes were parathyroid gland identification rates, rates of parathyroid gland autotransplantation, and rates of inadvertent parathyroid gland excision.

Results

A total of 89 patients were included in the final analysis. A total of 33 patients (37.1%) experienced immediate hypoparathyroidism following surgery, while 30 patients (33.7%) still were on active vitamin D two months postoperatively. One year following surgery, 28 patients (31.5%) were still on active vitamin D and were considered as having permanent hypoparathyroidism. Sixty-one percent of the parathyroid glands were identified intraoperatively, and 19% of the patients experienced parathyroid autotransplantation. Inadvertent parathyroid gland excision occurred for 21% of the patients and was associated with a significantly increased risk of permanent hypoparathyroidism (RR = 2.99; 95% CI: 1.36 - 6.62, p = 0.005).

Conclusion

Both transient and permanent hypoparathyroidism following total thyroidectomy at a low-volume, non-parathyroid institution occurred with much higher frequencies than previously reported. The elevated rates were most likely due to the low-volume, non-parathyroid nature of the surgeons which in part was mirrored in low parathyroid gland identifications rates, and high rates of autotransplantation and inadvertent parathyroid gland excision.

Primary Hyperparathyroidism in Young and Adolescents: Alike or Unlike Adult Hyperparathyroidism? - A Series from South India

Background

Primary hyperparathyroidism (PHPT) is a common endocrine condition but rare in the pediatric and adolescent populations. The presentations can be unique, accounting for significant morbidity in the case of untimely detection.

Aim

To study surgically treated pediatric PHPT retrospectively.

Methods

Surgically treated children of PHPT up to 20 years of age between 2010 to 2022 were analyzed. All of them were operated on by an endocrine surgeon and team.

Results

There was a total of 712 parathyroidectomies over 12 years, out of which there were 52 children (7.3%) had PHPT at less than 20 years of age. This group included 32 male children. The mean age was 16.1 years, including 7 cases of neonatal severe HPT. Multiple Endocrine Neoplasia type 1 was confirmed in 12 children. Presentations were more severe like bone pain (35.13%), renal stones (27.02%), incidental asymptomatic detection (18.9%), failure to thrive (10.8%), and pancreatitis (8.1%) as compared to adults. Mean serum calcium was 12.9 mg/dl (highest-14.1, N-8.8-10.8 mg/dl), mean parathormone levels were 386.91 pg/ml (N-10-65) and vitamin D levels ranged from 2.9-22.8 ng/ml. Localization was done with ultrasound and 99mTc- SESTAMIBI scans. Mean serum calcium levels in NSPHPT were 28.6 mg/dl (N-8.8-10.8 mg/dl). There were a total of 45 cases (6.32%) of PHPT less than 20 years of age, excluding the cases of NSPHPT. All children underwent parathyroidectomy, with 14 cases having an additional thymectomy, 2 cases with thyroidectomy, and a single case of hemithyroidectomy. The cure rate was 97.3%, while one baby with NSPHPT had persistent disease (postop PTH-110 pg/ml). The uniglandular disease was seen in 54.05% and the rest had a multiglandular disease. Adults accounted for 559/660 cases with 80% uniglandular disease. All cases had a postoperative histopathological confirmation with an average follow-up of 1 year.

Conclusion

Childhood PHPT has a few features same as the adult population. Symptomatic presentations like adults, though pancreatitis and fatigue were more commonly seen as compared to bone pain. Calcium, phosphorus, and parathormone levels were comparable. Uniglandular involvement was seen just like the adult population. There are a few others that make them a distinct subtype like their symptoms of bone pain and being more common among boys. One-fourth of them had MEN1. Fewer cases in this age group make them unique.

The effects of adequate dietary calcium intake in patients with hypoparathyroidism non-adherent to treatment: a prospective randomized controlled trial

OBJECTIVE

A significant problem that compels clinicians in the conventional treatment of hypoparathyroidism is patients' non-adherence to treatment. This study aimed to evaluate the effects of adequate Ca intake with dietary recommendations among hypoparathyroidism patients who persistently use Ca supplementation irregularly on plasma Ca and phosphate levels.

METHODS

This prospective, randomized, controlled study was conducted on patients diagnosed with chronic hypoparathyroidism who persistently interrupt Ca supplementation therapy and therefore have a hypocalcemic course. Patients with a total daily Ca intake below 800 mg were randomized. All patients were advised to keep the doses of active vitamin D and Ca supplements they were currently using. The patients in the study group (n=32) were advised to consume 1,000-1,200 mg of Ca daily, and the patients in the control group (n=35) were advised to continue their diet according to their daily habits. After 12 weeks of follow-up, the patients' laboratory values were compared between groups to assess treatment goals.

RESULTS

The mean of the total Ca level was 8.56±0.36 mg/dL in the study group and was found to be significantly higher than that in the control group, which was 7.67±0.48 mg/dL (p<0.001). The mean serum phosphate and serum Ca-P product levels were significantly higher in the study group (p<0.001) but did not exceed the safe upper limits in any patient.

CONCLUSION

A suitable increase in dietary Ca intake could effectively control hypocalcemia in patients with hypoparathyroidism who persistently interrupt the recommended calcium supplementation.

Case report: A case of hypocalcemic cardiomyopathy with non-reversible cardiac fibrosis

Hypocalcemic cardiomyopathy is a rare etiology of heart failure. It is considered highly reversible with a relatively favorable prognosis. This case reports a 52-year-old housewife diagnosed with hypocalcemic cardiomyopathy who presented with acute decompensated heart failure and hypocalcemia symptoms with a history of thyroidectomy. Shortness of breath and edema were relieved after diuresis and prompt electrolyte correction. The left ventricular ejection fraction increased from 27% to 53%, and the left ventricular end-diastolic dimension shortened from 58 to 50 mm in echocardiographic re-examinations, while repeat cardiac magnetic resonance imaging revealed evidence of non-reversible cardiac fibrosis after 1-year follow-up. Cardioprotective agents with close follow-ups were called for in this entity of patients.

Correlation between visual scores and parathyroid function

This mini review summarizes the controversies regarding routine parathyroid identification reviews publications that assess visual scores to predict parathyroid function after thyroidectomy during the pre-ICG era.

Vitamin D in hypoparathyroidism: insight into pathophysiology and perspectives in clinical practice

Hypoparathyroidism (HypoPT) is a rare endocrine disorder characterized by the absence or insufficient parathyroid hormone production resulting in chronic hypocalcemia. Complications of HypoPT include perturbation of several target organs. The conventional treatment consists of the administration of active vitamin D, namely calcitriol. Regarding vitamin D status, few data are available, mostly in HypoPT subjects supplemented with parent vitamin D. In addition, perturbation of vitamin D metabolism has been poorly investigated, as well as the contribution of altered vitamin D status on the clinical expression of the disease. The most recent consensus on the management of chronic HypoPT suggests the baseline evaluation of serum 25-hydroxy-vitamin D [25(OH)D] and supplementation with parent vitamin D with the aim to achieve and maintain serum 25(OH)D levels in the range of 30-50 ng/mL. The rationale for using supplementation with parent vitamin D (either ergocalciferol or cholecalciferol) in HypoPT would be to provide sufficient 25(OH)D substrate to the residual 1-α-hydroxylase activity, thus ensuring its conversion to active vitamin D in renal and extra-renal tissues. More data from experimental and clinical studies are needed for better assessing how these mechanisms may significantly influence metabolic control in HypoPT and eventually skeletal and extra-skeletal manifestation of the disease. Finally, future data will clarify how the currently available parent vitamin D compounds (ergocalciferol, cholecalciferol, calcifediol) would perform in addressing these specific issues.