Characteristics, management and outcomes of primary hyperparathyroidism from 2009 to 2021: a single centre report from South Africa

BACKGROUND

There has been a notable shift towards the diagnosis of less severe and asymptomatic primary hyperparathyroidism (PHPT) in developed countries. However, there is a paucity of recent data from sub-Saharan Africa (SSA), and also, no reported data from SSA on the utility of intra-operative parathyroid hormone (IO-PTH) monitoring. In an earlier study from Inkosi Albert Luthuli Central Hospital (IALCH), Durban, South Africa (2003-2009), majority of patients (92.9%) had symptomatic disease. The aim of this study was to evaluate the clinical profile and management outcomes of patients presenting with PHPT at IALCH.

METHODS

A retrospective chart review of patients with PHPT attending the Endocrinology clinic at IALCH between July 2009 and December 2021. Clinical presentation, laboratory results, radiologic findings, surgical notes and histology were recorded.

RESULTS

Analysis included 110 patients (87% female) with PHPT. Median age at presentation was 57 (44; 67.5) years. Symptomatic disease was present in 62.7% (n:69); 20.9% (n:23) had a history of nephrolithiasis and 7.3% (n:8) presented with previous fragility fractures. Mean serum calcium was 2.87 ± 0.34 mmol/l; median serum-PTH was 23.3 (15.59; 45.38) pmol/l, alkaline phosphatase 117.5 (89; 145.5) U/l and 25-hydroxyvitamin-D 42.9 (33.26; 62.92) nmol/l. Sestamibi scan (n:106 patients) identified an adenoma in 83.02%. Parathyroidectomy was performed on 84 patients with a cure rate of 95.2%. Reasons for conservative management (n:26) included: no current surgical indication (n:7), refusal (n:5) or deferral of surgery (n:5), loss to follow-up (n:5) and assessed as high anaesthetic risk (n:4). IO-PTH measurements performed on 28 patients indicated surgical success in 100%, based on Miami criteria. Histology confirmed adenoma in 88.1%, hyperplasia in 7.1% and carcinoma in 4.8%. Post-operative hypocalcaemia developed in 30 patients (35.7%), of whom, 14 developed hungry bone syndrome (HBS). In multivariate analysis, significant risk factors associated with HBS included male sex (OR 7.01; 95% CI 1.28, 38.39; p 0.025) and elevated pre-operative PTH (OR 1.01; 95% CI 1.00, 1.02; p 0.008).

CONCLUSIONS

The proportion of asymptomatic PHPT has increased at this centre over the past decade but symptomatic disease remains the dominant presentation. Parathyroidectomy is curative in the majority of patients. IO-PTH monitoring is valuable in ensuring successful surgery.

Hypercalcemic Crisis Due to Parathyroid Adenoma Improved by Continuous Hemodialysis with a Common Calcium Concentration Dialysate: Discussion of Therapeutic Management

A hypercalcemic crisis due to primary hyperparathyroidism is a life-threatening condition. We herein report a 71-years-old man with hypercalcemic crisis due to primary hyperparathyroidism with parathyroid adenoma. Generally, hemodialysis or continuous hemodiafiltration using calcium-free or low-calcium dialysate is performed early for hypercalcemic crisis. In this case, continuous hemodialysis with a common calcium concentration dialysate improved the hypercalcemic crisis, and parathyroidectomy was performed. The patient recovered sufficiently. Prediction of hypercalcemia crisis, appropriate introduction and methods of blood purification therapy, and timing decisions for parathyroidectomy are required for therapeutic management of hypercalcemic crisis with parathyroid adenoma.

Primary hyperparathyroidism in adults-(Part I) assessment and medical management: Position statement of the endocrine society of Australia, the Australian & New Zealand endocrine surgeons, and the Australian & New Zealand bone and mineral society

OBJECTIVE

To formulate clinical consensus recommendations on the presentation, assessment, and management of primary hyperparathyroidism (PHPT) in adults.

METHODS

Representatives from relevant Australian and New Zealand Societies used a systematic approach for adaptation of guidelines (ADAPTE) to derive an evidence-informed position statement addressing nine key questions.

RESULTS

PHPT is a biochemical diagnosis. Serum calcium should be measured in patients with suggestive symptoms, reduced bone mineral density or minimal trauma fractures, and in those with renal stones. Other indications are detailed in the manuscript. In patients with hypercalcaemia, intact parathyroid hormone, 25-hydroxy vitamin D, phosphate, and renal function should be measured. In established PHPT, assessment of bone mineral density, vertebral fractures, urinary tract calculi/nephrocalcinosis and quantification of urinary calcium excretion is warranted. Parathyroidectomy is the only definitive treatment and is warranted for all symptomatic patients and should be considered for asymptomatic patients without contraindications to surgery and with >10 years life expectancy. In patients who do not undergo surgery, we recommend annual evaluation for disease progression. Where the diagnosis is not clear or the risk-benefit ratio is not obvious, multidisciplinary discussion and formulation of a consensus management plan is appropriate. Genetic testing for familial hyperparathyroidism is recommended in selected patients.

CONCLUSIONS

These clinical consensus recommendations were developed to provide clinicians with contemporary guidance on the assessment and management of PHPT in adults. It is anticipated that improved health outcomes for individuals and the population will be achieved at a decreased cost to the community.

[Diagnosis and management of primary hyperparathyroidism during pregnancy: A systematic review and a longitudinal case study]

OBJECTIVE

There is no specific recommendation for management in pregnant women: the aim of this review, based on a clinical case study, is to clarify its development, complications, risk factor and treatment.

METHODS

A review of the literature was performed by consulting the Pubmed, Cochrane Library, and Science Direct databases.

RESULTS

Primary hyperparathyroidism is defined as excessive production of parathyroid hormone resulting in hypercalcemia. The prevalence of primary hyperparathyroidism during pregnancy is not known. Indeed, the symptomatology, related to hypercalcemia, is not very specific and easily confused with the clinical manifestations of pregnancy. The physiological changes specific to the pregnant state frequently lead to a slight hypocalcemia which may complicate the diagnosis of primary hyperparathyroidism. Primary hyperparathyroidism results from a parathyroid adenoma in the majority of cases and is detected by ultrasound during pregnancy. Primary hyperparathyroidism in pregnancy causes significant risks to both mother and fetus. The maternal complication rate is 14-67%, however, the most serious complication is hypercalcemic crisis, which requires increased surveillance in the postpartum period. Obstetrical complications are also induced by primary hyperparathyroidism, such as acute polyhydramnios, or intrauterine growth retardation. The fetal complication rate can reach 45-80% of cases with neonatal hypocalcemia as the main complication. If medical treatment is based on hyperhydration, only surgical treatment is curative.

CONCLUSION

Surgery should be proposed to symptomatic patients or those with high blood calcium levels, discussed in interdisciplinary committee and should be organized ideally in the second trimester to avoid maternal and fetal complications.

Expert consensus on multidisciplinary approach to the diagnosis and treatment of primary hyperparathyroidism in pregnancy in China

Primary hyperparathyroidism in pregnancy is a rare disease that can have detrimental effects on both maternal and fetal/neonatal outcomes. The physiological changes that occur during pregnancy can complicate the diagnosis, imaging examinations, and treatment of this disorder. To enhance our understanding and management of primary hyperparathyroidism in pregnancy, experts from various fields, including endocrinology, obstetrics, surgery, ultrasonography, nuclear medicine, pediatrics, nephrology, and general practice in China, collaborated to develop a consensus addressing the critical aspects of the diagnosis and treatment of primary hyperparathyroidism in pregnancy with a multidisciplinary team approach. This consensus provides valuable guidance for healthcare professionals in managing this condition, ultimately improving outcomes for both mothers and their babies.

Evaluation of risk factors for recurrent renal stone formation among Saudi Arabian patients: Comparison with first renal stone episode

OBJECTIVES

We evaluated the baseline characteristics, and risk factors of renal stone recurrence among Saudi Arabian patients after successful primary stone treatment.

MATERIALS AND METHODS

In this cross-sectional comparative study, we reviewed the medical records of patients who presented consecutively with a first renal stone episode from 2015 to 2021 and were followed-up by mail questionnaire, telephone interviews, and/or outpatient clinic visit. We included patients who achieved stone-free status after primary treatment. Patients were divided into two groups: group I (patients with first episode renal stone) and group Ⅱ (patients who developed renal stone recurrence). The study outcomes were to compare the demographics of both groups and to evaluate the risk factors of renal stone recurrence after successful primary treatment. We used Student's t-test, Mann Whitney test or chi-square (x2) to compare variables between groups. Cox regression analyses were used to examine the predictors.

RESULTS

We investigated 1260 participants (820 males and 440 females). Of this number, 877 (69.6%) didn't develop renal stone recurrence and 383 (30.4%) had recurrence. Primary treatments were percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), extracorporeal shock wave lithotripsy (ESWL), surgery and medical treatment in 22.5%, 34.7%, 26.5%, 10.3%, and 6%, respectively. After primary treatment, 970 (77%) and 1011 (80.2%) of patients didn't have either stone chemical analysis or metabolic work-up, respectively. Multivariate logistic regression analysis revealed that male gender (OR: 1.686; 95% CI, 1.216-2.337), hypertension (OR: 2.342; 95% CI, 1.439-3.812), primary hyperparathyroidism (OR: 2.806; 95% CI, 1.510-5.215), low fluid intake (OR: 28.398; 95% CI, 18.158-44.403) and high daily protein intake (OR: 10.058; 95% CI, 6.400-15.807) were predictors of renal stone recurrence.

CONCLUSIONS

Male gender, hypertension, primary hyperparathyroidism, low fluid intake and high daily protein intake increase the risk of renal stone recurrence among Saudi Arabian patients.

Quality of Life in Primary Hyperparathyroidism

Quality of life is impaired in primary hyperparathyroidism (PHPT), regardless of the severity of the disease. Clinical studies have employed different instruments, including standardized and disease-specific questionnaires, and including patients with different phenotypes of PHPT. Neuropsychiatric symptoms and decline in cognitive status are common in PHPT. Patients may complain of these issues or they can be ascertained by questionnaires; they include depression, anxiety, impaired vitality, social and emotional functions, sleep disturbances, and altered mental function. Randomized controlled trials on the effects of surgical versus non-surgical treatments have collectively shown improvement in quality of life after parathyroidectomy, but results have been heterogeneous.

Hypercalcemia: A Review

IMPORTANCE

Hypercalcemia affects approximately 1% of the worldwide population. Mild hypercalcemia, defined as total calcium of less than 12 mg/dL (<3 mmol/L) or ionized calcium of 5.6 to 8.0 mg/dL (1.4-2 mmol/L), is usually asymptomatic but may be associated with constitutional symptoms such as fatigue and constipation in approximately 20% of people. Hypercalcemia that is severe, defined as total calcium of 14 mg/dL or greater (>3.5 mmol/L) or ionized calcium of 10 mg/dL or greater (≥2.5 mmol/L) or that develops rapidly over days to weeks, can cause nausea, vomiting, dehydration, confusion, somnolence, and coma.

OBSERVATIONS

Approximately 90% of people with hypercalcemia have primary hyperparathyroidism (PHPT) or malignancy. Additional causes of hypercalcemia include granulomatous disease such as sarcoidosis, endocrinopathies such as thyroid disease, immobilization, genetic disorders, and medications such as thiazide diuretics and supplements such as calcium, vitamin D, or vitamin A. Hypercalcemia has been associated with sodium-glucose cotransporter 2 protein inhibitors, immune checkpoint inhibitors, denosumab discontinuation, SARS-CoV-2, ketogenic diets, and extreme exercise, but these account for less than 1% of causes. Serum intact parathyroid hormone (PTH), the most important initial test to evaluate hypercalcemia, distinguishes PTH-dependent from PTH-independent causes. In a patient with hypercalcemia, an elevated or normal PTH concentration is consistent with PHPT, while a suppressed PTH level (<20 pg/mL depending on assay) indicates another cause. Mild hypercalcemia usually does not need acute intervention. If due to PHPT, parathyroidectomy may be considered depending on age, serum calcium level, and kidney or skeletal involvement. In patients older than 50 years with serum calcium levels less than 1 mg above the upper normal limit and no evidence of skeletal or kidney disease, observation may be appropriate. Initial therapy of symptomatic or severe hypercalcemia consists of hydration and intravenous bisphosphonates, such as zoledronic acid or pamidronate. In patients with kidney failure, denosumab and dialysis may be indicated. Glucocorticoids may be used as primary treatment when hypercalcemia is due to excessive intestinal calcium absorption (vitamin D intoxication, granulomatous disorders, some lymphomas). Treatment reduces serum calcium and improves symptoms, at least transiently. The underlying cause of hypercalcemia should be identified and treated. The prognosis for asymptomatic PHPT is excellent with either medical or surgical management. Hypercalcemia of malignancy is associated with poor survival.

CONCLUSIONS AND RELEVANCE

Mild hypercalcemia is typically asymptomatic, while severe hypercalcemia is associated with nausea, vomiting, dehydration, confusion, somnolence, and coma. Asymptomatic hypercalcemia due to primary hyperparathyroidism is managed with parathyroidectomy or observation with monitoring, while severe hypercalcemia is typically treated with hydration and intravenous bisphosphonates.

Different treatment strategies in primary hyperparathyroidism during pregnancy

PURPOSE

Primary hyperparathyroidism (PHPT) in pregnancy is rare enough and can be unrecognized because of nonspecific symptoms in most cases, but life-threatening complications for mother, fetus and neonate also occurs. PHPT requires frequent monitoring of the mother and fetus by a multidisciplinary team. Diagnostics and treatment approaches are limited and require individual risk-benefit assessment.

METHODS

In this paper we describe 3 cases of PHPT in pregnant women with different managing approaches (surveillance, drug therapy and surgical treatment) and successful outcomes. Additionally, the most actual literature data on this problem is reviewed.

RESULTS

The management of PHPT in pregnancy should be based on the clinical features, severity of hypercalcemia, gestational age and patient's preference. In the first case a conservative approach with low-calcium diet and oral hydration resulted in mother's reduced serum calcium level before delivery. The second patient had severe hypercalcemia and absolute indications for surgery that was successfully performed at 25 week of gestation. The third woman received cinacalcet because of severe hypercalcemia and potential perioperative risks in the third trimester with an improvement in well-being.

CONCLUSION

Nowadays parathyroidectomy is the best choice for patients with symptomatic PHPT and severe hypercalcemia. This intervention should be carried out preferably in the second trimester to avoid maternal and fetal complications. Mild forms of the disease can require just a conservative management. The drug treatment of PHPT during pregnancy is still controversial.

Parathyroid Disorders

Parathyroid disorders are most often identified incidentally by abnormalities in serum calcium levels when screening for renal or bone disease or other conditions. Parathyroid hormone, which is released by the parathyroid glands primarily in response to low calcium levels, stimulates osteoclastic bone resorption and serum calcium elevation, reduces renal calcium clearance, and stimulates intestinal calcium absorption through synthesis of 1,25-dihydroxyvitamin D. Primary hyperparathyroidism, in which calcium levels are elevated without appropriate suppression of parathyroid hormone levels, is the most common cause of hypercalcemia and is often managed surgically. Indications for parathyroidectomy in primary hyperparathyroidism include presence of symptoms, age 50 years or younger, serum calcium level more than 1 mg per dL above the upper limit of normal, osteoporosis, creatinine clearance less than 60 mL per minute per 1.73 m2, nephrolithiasis, nephrocalcinosis, and hypercalciuria. Secondary hyperparathyroidism is caused by alterations in calcium, phosphate, and vitamin D regulation that result in elevated parathyroid hormone levels. It most commonly occurs with chronic kidney disease and vitamin D deficiency, and less commonly with gastrointestinal conditions that impair calcium absorption. Secondary hyperparathyroidism can be managed with calcium and vitamin D replacement and reduction of high phosphate levels. There is limited evidence for the use of calcimimetics and vitamin D analogues for persistently elevated parathyroid hormone levels. Hypoparathyroidism, which is most commonly caused by iatrogenic surgical destruction of the parathyroid glands, is less common and results in hypocalcemia. Multiple endocrine neoplasia types 1 and 2A are rare familial syndromes that can result in primary hyperparathyroidism and warrant genetic testing of family members, whereas parathyroid cancer is a rare finding in patients with hyperparathyroidism.

European Expert Consensus on Practical Management of Specific Aspects of Parathyroid Disorders in Adults and in Pregnancy: Recommendations of the ESE Educational Program of Parathyroid Disorders

This European expert consensus statement provides recommendations for the diagnosis and management of primary hyperparathyroidism (PHPT), chronic hypoparathyroidism in adults (HypoPT), and parathyroid disorders in relation to pregnancy and lactation. Specified areas of interest and unmet needs identified by experts at the second ESE Educational Program of Parathyroid Disorders (PARAT) in 2019, were discussed during two virtual workshops in 2021, and subsequently developed by working groups with interest in the specified areas. PHPT is a common endocrine disease. However, its differential diagnosing to familial hypocalciuric hypercalcemia (FHH), the definition and clinical course of normocalcemic PHPT, and the optimal management of its recurrence after surgery represent areas of uncertainty requiring clarifications. HypoPT is an orphan disease characterized by low calcium concentrations due to insufficient PTH secretion, most often secondary to neck surgery. Prevention and prediction of surgical injury to the parathyroid glands are essential to limit the disease-related burden. Long-term treatment modalities including the place for PTH replacement therapy and the optimal biochemical monitoring and imaging surveillance for complications to treatment in chronic HypoPT, need to be refined. The physiological changes in calcium metabolism occurring during pregnancy and lactation modify the clinical presentation and management of parathyroid disorders in these periods of life. Modern interdisciplinary approaches to PHPT and HypoPT in pregnant and lactating women and their newborns children are proposed. The recommendations on clinical management presented here will serve as background for further educational material aimed for a broader clinical audience, and were developed with focus on endocrinologists in training.

Hereditary Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a commonly encountered clinical problem and occurs as part of an inherited disorder in ∼10% of patients. Several features may alert the clinician to the possibility of a hereditary PHPT disorder (eg, young age of disease onset) whilst establishing any relevant family history is essential to the clinical evaluation and will help inform the diagnosis. Genetic testing should be offered to patients at risk of a hereditary PHPT disorder, as this may improve management and allow the identification and investigation of other family members who may also be at risk of disease.

Systems-Level Opportunities in the Management of Primary Hyperparathyroidism: An Informatics-based Assessment

CONTEXT

Primary hyperparathyroidism (PHPT), a leading cause of hypercalcemia and secondary osteoporosis, is underdiagnosed.

OBJECTIVE

This work aims to establish a foundation for an electronic medical record-based intervention that would prompt serum parathyroid hormone (PTH) assessment in patients with persistent hypercalcemia and identify care gaps in their management.

METHODS

A retrospective cohort study was conducted in a tertiary academic health system of outpatients with persistent hypercalcemia, who were categorized as having classic or normohormonal PHPT. Main outcome measures included the frequencies of serum PTH measurement in patients with persistent hypercalcemia, and their subsequent workup with bone mineral density (BMD) assessment, and ultimately, medical therapy or parathyroidectomy.

RESULTS

Among 3151 patients with persistent hypercalcemia, 1526 (48%) had PTH measured, of whom 1377 (90%) were confirmed to have classic (49%) or normohormonal (41%) PHPT. PTH was measured in 65% of hypercalcemic patients with osteopenia or osteoporosis (P < .001). At median 2-year follow-up, bone density was assessed in 275 (20%) patients with either variant of PHPT (P = .003). Of women aged 50 years or older with classic PHPT, 95 (19%) underwent BMD assessment. Of patients with classic or normohormonal PHPT, 919 patients (67%) met consensus criteria for surgical intervention, though only 143 (15%) underwent parathyroidectomy.

CONCLUSION

Within a large academic health system, more than half of patients with confirmed hypercalcemia were not assessed for PHPT, including many patients with preexisting bone disease. Care gaps in BMD assessment and medical or surgical therapy represent missed opportunities to avoid skeletal and other complications of PHPT.

Safety and efficacy of common vitamin D supplementation in primary hyperparathyroidism and coexistent vitamin D deficiency and insufficiency: a systematic review and meta-analysis

PURPOSE

Primary hyperparathyroidism (PHPT) is characterized by excessive secretion of parathyroid hormone (PTH). Vitamin D deficiency can stimulate parathyroid secretion. However, whether to correct vitamin D deficiency in patients with PHPT is controversial. We aimed to evaluate the safety and efficacy of vitamin D replacement in patients with PHPT.

METHODS

We searched PubMed, Cochrane Library, and Embase. The relevant data were extracted from the included documents. The methodological items for non-randomized studies score entries were used for evaluation of quality. Review Manager 5.3 and Stata 12.0 were used for statistical analysis.

RESULTS

A total of 11 articles were included with a total of 388 patients. The serum calcium mean difference (MD) was - 0.06 mg/dL [95% confidence interval (95% CI) - 0.16, 0.04]. Subgroup analysis showed that serum calcium levels did not change if the intervention time exceeded 1 month. The 24-h urinary calcium MD was 36.78 mg/day (95% CI - 37.15, 110.71), which indicated that there was no significant effect of vitamin D supplementation on 24-h urinary calcium levels. The MD of PTH was - 16.01 pg/mL (95% CI - 28.79, - 3.24). Subgroup analysis according to the intervention time showed that vitamin D intervention for more than 1 month significantly reduced PTH levels. The ALP MD was - 10.81 U/L (95% CI - 13.98, - 7.63), which indicated Vitamin D supplementation reduced its level. The MD of 25-hydroxyvitamin D was 22.09 μg/L (95% CI 15.01, 29.17), and no source of heterogeneity was found.

CONCLUSION

Vitamin D supplementation in patients with PHPT and vitamin D deficiency significantly reduces PTH and ALP levels without causing hypercalcemia and hypercalciuria.

Efficacy of parathyroidectomy compared with active surveillance in patients with mild asymptomatic primary hyperparathyroidism: a systematic review and meta-analysis of randomized-controlled studies

OBJECTIVE

Parathyroidectomy (PTx) has an established benefit in patients with symptomatic primary hyperparathyroidism (PHPT). However, its efficacy in mild asymptomatic PHPT has not been proven. This study aimed to systematically review and meta-analyze the best available evidence from randomized-controlled trials comparing the efficacy of PTx over conservative management (non-PTx) on skeletal outcomes [fractures and bone mineral density (BMD)], nephrolithiasis risk and quality of life (QoL) in patients with mild asymptomatic PHPT.

METHODS

A comprehensive literature search was conducted in PubMed, Scopus and Cochrane databases, from conception to February 23, 2020. Data were extracted from the studies that fulfilled the eligibility criteria and were synthesized quantitatively (fixed or random effects model) as relative risks and percentage mean differences (MD) with 95% confidence intervals (CI). I² index was employed for heterogeneity.

RESULTS

Four studies were included in the meta-analysis. There was no difference in fracture risk between PTx and active surveillance. The PTx group demonstrated higher BMD [MD 3.55% (95% CI 1.81, 5.29) in lumbar spine and 3.44% (95% CI 1.39, 5.49) in total hip, without difference in femoral neck and forearm] and lower calcium concentrations (MD - 13.26%, 95% CI - 7.10, - 19.43) compared with the non-PTx group. No difference was observed between groups regarding nephrolithiasis or QoL indices, except for general health (higher in PTx group).

CONCLUSIONS

In patients with mild asymptomatic PHPT, PTx increases BMD and reduces serum calcium concentrations. However, its superiority over active surveillance in terms of fracture risk, nephrolithiasis and QoL cannot be supported by current data.

Clinical Characteristics of Primary Hyperparathyroidism: 15-Year Experience of 457 Patients in a Single Center in China

Objective

Primary hyperparathyroidism (PHPT) is a common endocrine disorder of calcium metabolism. However, data concerning a large cohort of PHPT patients in the Chinese population are scarce. Thus, the objective of this study was to determine the general clinical signatures of 457 Chinese PHPT patients and explore the clinical characteristic differences between benign and malignant PHPT.

Methods

A single-center retrospective study was designed. Medical records between preoperation and postoperative follow-up, were assessed and statistical analysis of the clinical data was performed.

Results

Patients with PHPT aged 12-87 years, with a mean onset age of 56.16 ± 14.60 years, were included. Most patients (68.7%) in our center had symptomatic patterns described as bone pain (74.8%), urolithiasis (25.5%), fatigue (17.5%), and pathological fracture (13.1%), but an increasing tendency has been established in the proportion of patients with asymptomatic forms. Correlation analysis revealed that patients with higher serum levels of parathyroid hormone (PTH) and calcium presented higher serum levels of bone turnover markers (BTMs) and lower 25-hydroxy-vitamin D (25OHD) values (P<0.001). Gains in bone mineral density (BMD) at L1-4, the femoral neck and the total hip were observed 1-2 years after parathyroidectomy (9.6, 5.9, and 6.8%). Parathyroid carcinoma patients presented prominently higher serum PTH and calcium levels and BTMs and lower BMD at femoral neck and total hip than benign PHPT patients (P<0.05), while no significant differences in age, sex, and serum 25OHD concentration were observed between benign and malignant PHPT patients.

Conclusions

PHPT should be paid attention to in the patients with bone pain. While, BMD and BTMs can differentiate parathyroid carcinoma from parathyroid adenoma and hyperplasia to some extent. In addition, anti-osteoporosis drugs could be used when necessary to avoid hip fractures in patients with parathyroid carcinoma.

Management of parathyroid disorders: recommendations of the working group of the Bone Section of the Hellenic Endocrine Society

The Bone Section of the Hellenic Endocrine Society has issued the recommendations herein presented with the aim of providing guidance on optimal management of patients with parathyroid disorders in everyday clinical practice within the Greek health care setting. Although the methodology followed to formulate these recommendations was not strictly based on the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) principles, they were drawn up after an extensive review of the literature and of the currently available guidelines for the management of parathyroid disorders worldwide. Specifically for primary hyperparathyroidism (PHPT), the 2011 guidelines of the Greek National Organization of Medicines were updated accordingly. In particular, definitions, etiologies, and recommended and optional laboratory and imaging examinations are provided both for PHPT and chronic hypoparathyroidism (HypoPT). Finally, treatment algorithms are provided for the management of both PHPT and HypoPT. Specifically for HypoPT, the treatment algorithm describes the recommended steps that should be followed to achieve optimal management of chronic hypocalcemia and the complications of HypoPT through the conventional treatment available in Greece and the use of recombinant human PTH(1-84).

Persistent hyperparathyroidism due to mediastinal parathyroid adenoma treated with selective arterial embolization with embosphere: first case in the literature

Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia in the clinical setting and affects 0.3% of the population. Parathyroidectomy is the only definitive cure. Unfortunately, even in the most experienced hands, persistent primary hyperparathyroidism (P-PHPT) occurs in 4.7% of the patients. Ectopic adenomas are difficult to localize before and during operation and usually end up with P-PHPT. Herein, we presented a case with P-PHPT due to mediastinal parathyroid adenoma that was successfully ablated with selective arterial embolization. A 57-year-old female patient was admitted to our endocrinology clinic with persistent hypercalcemia 4 months after the initial surgery for PHPT that had been performed in another center. The patient did not accept the second operation, and serum calcium and parathyroid hormone (PTH) remained high despite medical treatment with cinacalcet and IV zoledronate. In the 99-m Tc-MIBI scintigraphy with SPECT, a 18 × 12-mm-sized lesion in the mediastinum at the paratracheal region was detected which was confirmed to be a possible parathyroid adenoma with fluorocholine PET and chest computed tomography (CT). The right bronchial artery that was detected to supply the mediastinal mass in CT angiography was selectively catheterized and embolized with embosphere. Right after the procedure, serum PTH and calcium levels were normalized and remained normal in 23 months of follow-up. Selective arterial embolization is a treatment option for ectopically located adenomas which are difficult to resect and in cases with certain comorbidities which constitute a contraindication for surgery.

Primary hyperparathyroidism and pancreatitis

PURPOSE

The true association between primary hyperparathyroidism (PHPT) and pancreatitis continues to be controversial. In this study, we present clinical data, investigative profile, management and follow-up of PHPT patients with pancreatitis and compare this group with PHPT patients without pancreatitis.

METHODS

Records of 242 patients with PHPT managed at our center over 24 years were retrospectively analyzed for demographic and laboratory data. The diagnosis of pancreatitis was entertained in the presence of at least two of the three following features: abdominal pain, levels of serum amylase greater than three times the normal or characteristic features at imaging.

RESULTS

Fifteen (6.19%) of the 242 consecutive patients with PHPT had had pancreatitis. Fourteen patients (93.3%) had acute pancreatitis (AP), while one patient had chronic calcific pancreatitis. Over half (8 of 14) of the patients with AP had at least two episodes of pancreatitis. Pancreatitis was the presenting symptom in 14 (93.3%) patients. None of the pancreatitis cases had additional risk factors for pancreatitis. PHPT patients with pancreatitis had significantly higher serum calcium and ALP than PHPT patients without pancreatitis. After successful parathyroidectomy, 14 patients had no further attacks of pancreatitis during a median follow-up of 16 months (range 2-41 months), while recurrence of pancreatitis was seen in one patient.

CONCLUSIONS

We conclude that pancreatitis can be the only presenting complaint of PHPT. Our study highlights the importance of fully investigating for PHPT in any pancreatitis patient with high normal or raised serum calcium level, especially in the absence of other common causes of pancreatitis.

Diagnostic and treatment delay in primary hyperparathyroidism. A pending issue

INTRODUCTION

Primary hyperparathyroidism (PHPT) remains underdiagnosed among patients with hypercalcemia, potentially causing increased morbidity.

OBJECTIVE

To identify in surgically operated patients the presence of overlooked hypercalcemia and patients with criteria for surgery (CFS) for PHPT at least one year prior to referral to Endocrinology, and to determine whether this diagnostic delay leads to increased morbidity.

METHODS

An observational study was carried out in 116 consecutive patients. We evaluated electronic medical records registered at least 12 months prior to referral and divided them in four groups: hypercalcemia with CFS (group 1), hypercalcemia without CFS (group 2), normocalcemia (group 3), and cases without previous biochemical evaluation (group 4).

RESULTS

A total of 84 patients (72.4%) had a previous measurement of serum calcium at a time interval of ≥ 12 months. Sixty-six (56.9%) had hypercalcemia and 43 of them (37%) had ≥ 1 CFS, with an average delay of 57 months in receiving proper evaluation. Almost half of the calcemia measurements in group 1 had been made in the emergency room. Patients from group 1 were younger, and had a greater frequency of nephrolithiasis and renal impairment than patients in group 4. The serum calcium values at referral were similar in both groups and higher than the values found in patients from the other two groups.

DISCUSSION

In patients with PHPT and CFS, referral to an endocrinologist is made with an average delay of almost 5 years. The identified causes of this delay, which conditions more kidney disease, are unrecognized hypercalcemia and/or unawareness of the surgical criteria, while calcium elevations promote referral. Interventions are needed to avoid this delay in the diagnosis and resolution of PHPT.

Calcium Metabolic Disorders in Pregnancy: Primary Hyperparathyroidism, Pregnancy-Induced Osteoporosis, and Vitamin D Deficiency in Pregnancy

Physiologic changes during pregnancy include calcium, phosphate, and calciotropic hormone status. Calcium metabolic disorders are rare in pregnancy and management with close calcium and vitamin D control and supplementation. Primary hyperparathyroidism is mostly asymptomatic and does not affect conception or pregnancy. It requires control of plasma calcium levels. Surgical intervention may be indicated. Data on severe cases are missing. Osteoporosis in or before pregnancy is rare but usually diagnosed from fractures. Medical treatment other than supplementation is contraindicated. Vitamin D deficiency is common and may affect conception and increase complications. Current evidence does not prove vitamin D supplements effective in improving outcomes.

Challenges in the treatment of parathyroid carcinoma: a case report

INTRODUCTION

Parathyroid carcinoma (PC) is a rare neoplasm with a high rate of recurrence and an indolent course. It is frequently functional, causing nearly 1% of the cases of primary hyperparathyroidism (HPT), and in some cases, it may be complicated by brown tumors, mimicking bone metastases. Synchronous parathyroid and papillary thyroid carcinomas are rare.

CASE REPORT

We present a patient with HPT due to PC, misdiagnosed at first evaluation, which exhibited multiple hypermetabolic lytic lesions in the skeleton, suggesting bone metastases. Their regression after PTH reduction suggested the diagnosis of brown tumors due to severe HPT. Given the persistence of HPT, the patient underwent a number of neck surgeries, and a papillary thyroid microcarcinoma with a nodal metastasis was diagnosed. A genetic test discovered a previously unreported mutation of the CDC73 (HRPT2) gene, codifying for parafibromin and resulting in a premature stop codon (c.580A>Tp.Arg194). Because of the persistence of HPT, cinacalcet therapy was started in order to control hypercalcemia.

CONCLUSION

This is a very unusual patient with a newly discovered variant of the CDC73 gene and a phenotype characterized by recurrent PC, brown tumors, and N1a metastasized thyroid carcinoma. The present case confirms that PC may not exhibit clear malignant properties at first assessment, contributing to inadequate initial surgical treatment. Although infrequently, PC can be associated with papillary thyroid cancer. The diagnosis of brown tumor should be considered in patients with severe HPT and multiple destructive bone lesions mimicking metastases on PET/CT imaging.

Primary Hyperparathyroidism in Pregnancy: Maternofetal Outcomes at a Quaternary Referral Obstetric Hospital, 2000 Through 2015

CONTEXT

Primary hyperparathyroidism (PHPT) in pregnancy has historically been associated with substantial maternofetal morbidity and mortality rates. The optimal treatment and timing of surgical intervention in pregnancy remain contested.

OBJECTIVE

To compare maternofetal outcomes of medically and surgically treated patients with PHPT in pregnancy.

DESIGN

Retrospective chart review.

SETTING

Quaternary referral hospital.

PATIENTS

Women with PHPT in pregnancy treated between 1 January 2000 and 31 December 2015.

INTERVENTIONS

Medical therapy or parathyroid surgery.

MAIN OUTCOMES MEASURED

Timing of diagnosis; maternal corrected serum calcium concentrations; gestation, indication and mode of delivery; complications attributable to PHPT; birth weight; and admission to the neonatal intensive care unit (NICU).

RESULTS

Twenty-two pregnancies were managed medically, and six patients underwent parathyroidectomy in pregnancy (five in trimester 2, and one at 32 weeks gestation). Most patients treated medically either had a corrected serum calcium concentration <2.85 mmol/L in early pregnancy or had PHPT diagnosed in trimester 3. Of viable medically managed pregnancies, 30% were complicated by preeclampsia, and preterm delivery occurred in 66% of this group. All preterm neonates required admission to the NICU for complications related to prematurity. All surgically treated patients delivered their babies at term, and there were no complications of parathyroid surgery.

CONCLUSION

Maternofetal outcomes have improved relative to that reported in early medical literature in patients treated medically and surgically, but the rates of preeclampsia and preterm delivery were higher in medically treated patients. The study was limited by its retrospective design and small sample sizes.

Primary Hyperparathyroidism

The 4 parathyroid glands derive from the third and fourth pharyngeal pouches and descend caudally to the anterior neck. Through the secretion of parathyroid hormone (PTH), the parathyroid glands are primarily responsible for maintaining extracellular calcium and phosphorus concentrations. Hypercalcemia may be distinguished in parathyroid-hypercalcemia and nonparathyroid hypercalcemia. The most common disorders include primary hyperparathyroidism (PHPT), malignancy, granulomatous diseases, and medications. PHPT is a disease characterized by excessive secretion of PTH. PHPT is most commonly due to a single benign parathyroid adenoma (80%) and with multiglandular disease seen in approximately 15-20% of patients. PHPT is due to multiglandular involvement consisting of either multiple adenomas or hyperplasia of all 4 glands (5-10%), and very rarely parathyroid carcinoma (<1%). In most patients the disease is sporadic, without a personal or family history of PHPT. The genetic syndromes associated with PHPT include multiple endocrine neoplasia type 1 (MEN1), MEN2A, and MEN4, hyperparathyroidism-jaw tumor syndrome, familial isolated PHPT, familial hypocalciuric hypercalcemia, and neonatal severe hyperparathyroidism. The asymptomatic clinical presentation is most common in countries where biochemical screening is routine. Conversely, target organ involvement at presentation dominates the clinical landscape of PHPT in other countries, such as China and India, where biochemical screening is not routine practice.

[Current approach to the diagnosis and treatment of primary hyperparathyroidism]

AIM

To optimize diagnosis and surgical treatment of patients with primary hyperparathyroidism.

MATERIAL AND METHODS

Retrospective comparative analysis of diagnosis and surgical treatment included 444 patients who were treated at the specialized department of endocrine surgery of Pirogov National Medical Surgical Center in 2012-2017. Archival materials and electronic databases of the clinic were applied.

RESULTS

It was developed the algorithm which may be used in most patients for minimally invasive parathyroidectomy. Minimally invasive surgery reduces the risk of complications and is associated with reliable efficacy and good cosmetic effect.

Non-surgical management of primary hyperparathyroidism

The purpose of this chapter is to discuss the options available for patients with primary hyperparathyrodism (PHPT) not undergoing parathyroidectomy (PTx). Adequate hydration should be recommended in all patients. Calcium intake should not be restricted and vitamin D deficiency should be corrected aiming at a serum concentration of 25OHD of >20 ng/mL or even higher (>30 ng/mL according to some opinion leaders). Pharmacologic therapy is not an alternative to PTx and could be considered in patients who meet the surgical criteria but unwilling to undergo PTx, as well as in patients with an increased risk of surgery or failed surgery. Targeted therapy includes antiresorptive drugs for skeletal protection and cinacalcet for lowering serum calcium. Combined therapy can be an option when appropriate. Pregnant women should be treated conservatively (hydration) and surgery, if needed, performed in the second trimester of pregnancy. Severe hypercalcemia is a life-threatening condition and requires immediate intensive treatment.

Management of normocalcemic primary hyperparathyroidism

Traditional hypercalcemic primary hyperparathyroidism is a common endocrine disease. Patients with a history of nephrolithiasis or a suspected metabolic bone disease are increasingly being identified with elevated PTH concentrations in the setting of consistently normal serum and ionized calcium concentrations. In the absence of secondary causes of hyperparathyroidism, a diagnosis of normocalcemic primary hyperparathyroidism is reasonable. As most cohorts described in the literature are from referral populations, involvement of the skeleton and the kidneys is common, two traditional target organs of primary hyperparathyroidism. Data from small cohorts show patients with normocalcemic disease respond similarly to hypercalcemic primary hyperparathyroidism with regard to medical and surgical approaches. In normocalcemic patients, multiglandular disease may be more common. In this article, we review the available literature on the epidemiology, diagnosis, clinical features, medical and surgical management of this newer phenotype of primary hyperparathyroidism.

Management of familial hyperparathyroidism syndromes: MEN1, MEN2, MEN4, HPT-Jaw tumour, Familial isolated hyperparathyroidism, FHH, and neonatal severe hyperparathyroidism

While primary hyperparathyroidism (PHPT) generally represents a common endocrine disorder, being the more frequent cause of hypercalcemia in outpatients, familial forms of PHPT (FPHPT) account for no more than 2-5% of the overall PHPT. In the last decades, many technical progresses in both molecular and biochemical-radiological evaluation have been made, and substantial advancements in understanding these disorders have been reached. Differences both in the pathogenesis and clinical presentation exist among the various hyperparathyroid syndromic forms, and, since FPHPT is frequently associated to other endocrine, proliferative and/or functional disorders, as also non-endocrine tumours, with varying clinical spectrum of occurrence in each syndrome, its early clinically detection for appropriately preventing complications (i.e. kidney and bone disorders) is strictly advised. In this review, the clinical-biochemical features and diagnostic procedures of each FPHPT form will be summarized and a general overview on surgical and pharmacological approaches to FPHPT has been also considered.

Normocalcemic Hyperparathyroidism

Parathyroid hormone (PTH) disorders are characterized by a wide spectrum of clinical and biochemical presentations. The increasing use of serum PTH assay in the set of the diagnostic workout in patients with osteoporosis has identified patients with features of surgically confirmed primary hyperparathyroidism (PHPT) associated with persistent normal serum calcium levels, which has been recognized as a distinct entity from hypercalcemic PHPT (HPHPT) by the last international consensus. Normocalcemic PHPT (NPHPT) affects about 6-8% of PHPT patients. Although hypercalcemia is absent, patients with NPHPT experience kidney, bone, and cardiovascular impairments similar to those observed in HPHPT, suggesting that NPHPT may significantly affect the health of patients. Diagnosis of NPHPT requires an intensive diagnostic workup aimed to: (1) exclude all causes of secondary hyperparathyroidism, and (2) evaluate the occurrence of PTH-related diseases. The management of NPHPT is controversial in part due to lack of solid data about the natural history as well as the effects of surgical or medical treatments. Nonetheless, a clinical and biochemical follow-up is recommended in order to detect potential progression. When hypercalcemia and/or PTH-related disorders arise, parathyroidectomy can be considered. When surgery is not advisable, medical treatment aimed to increase bone mineral density may be a therapeutic option.

Familial Hypocalciuric Hypercalcemia and Neonatal Severe Hyperparathyroidism

Familial hypocalciuric hypercalcemia (FHH) and neonatal severe hyperparathyroidism (NSHPT) are genetically determined variants of primary hyperparathyroidism. FHH usually has a benign course, and patients do not require treatment, whereas NSHPT is a severe disorder often requiring early parathyroidectomy for young patients to survive. Recent discoveries in the genetic basis and new findings in therapeutic approaches have led to a great interest in these rare diseases.

Asymptomatic Primary Hyperparathyroidism

Asymptomatic primary hyperparathyroidism has become the most common presentation of primary hyperparathyroidism in Europe and North America, and an increasingly common presentation in other parts of the world. As many as 25% of asymptomatic patients may develop indications for parathyroidectomy when followed long-term for up to 15 years. Patients who remain asymptomatic should be monitored for the development of complications that justify surgery. Patients who become symptomatic should be referred for surgery. Surgery may improve quality of life even in patients who remain asymptomatic.

Primary Hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT), the most common cause of hypercalcemia, is most often identified in postmenopausal women. The clinical presentation of PHPT has evolved over the past 40 years to include three distinct clinical phenotypes, each of which has been studied in detail and has led to evolving concepts about target organ involvement, natural history, and management.

METHODS

In the present review, I provide an evidence-based summary of this disorder as it has been studied worldwide, citing key concepts and data that have helped to shape our concepts about this disease.

RESULTS

PHPT is now recognized to include three clinical phenotypes: overt target organ involvement, mild asymptomatic hypercalcemia, and high PTH levels with persistently normal albumin-corrected and ionized serum calcium values. The factors that determine which of these clinical presentations is more likely to predominate in a given country include the extent to which biochemical screening is used, vitamin D deficiency is present, and whether parathyroid hormone levels are routinely measured in the evaluation of low bone density or frank osteoporosis. Guidelines for parathyroidectomy apply to all three clinical forms of the disease. If surgical guidelines are not met, parathyroidectomy can also be an appropriate option if no medical contraindications are present. If either the serum calcium or bone mineral density is of concern and surgery is not an option, pharmacological approaches are available and effective.

CONCLUSIONS

Advances in our knowledge of PHPT have guided new concepts in diagnosis and management.

Primary hyperparathyroidism

Primary hyperparathyroidism (PHPT), the most common cause of hypercalcemia, is most often identified in postmenopausal women with hypercalcemia and parathyroid hormone (PTH) levels that are either frankly elevated or inappropriately normal. The clinical presentation of PHPT includes three phenotypes: target organ involvement of the renal and skeletal systems; mild asymptomatic hypercalcemia; and more recently, high PTH levels in the context of persistently normal albumin-corrected and ionized serum calcium values. The factors that determine which of these three clinical presentations is more likely to predominate in a given country include the extent to which biochemical screening is employed, the prevalence of vitamin D deficiency, and whether a medical center or practitioner tends to routinely measure PTH levels in the evaluation of low bone density or frank osteoporosis. When biochemical screening is common, asymptomatic primary hyperparathyroidism is the most likely form of the disease. In countries where vitamin D deficiency is prevalent and biochemical screening is not a feature of the health care system, symptomatic disease with skeletal abnormalities is likely to predominate. Finally, when PTH levels are part of the evaluation for low bone mass, the normocalcemic variant is seen. Guidelines for surgical removal of hyperfunctioning parathyroid tissue apply to all three clinical forms of the disease. If guidelines for surgery are not met, parathyroidectomy can also be an appropriate option if there are no medical contraindications to surgery. In settings where either the serum calcium or bone mineral density is of concern, and surgery is not an option, pharmacological approaches are available and effective. Referencing in this article the most current published articles, we review the different presentations of PHPT, with particular emphasis on recent advances in our understanding of target organ involvement and management.

Familial hypocalciuric hypercalcemia and related disorders

Familial hypocalciuric hypercalcemia (FHH) causes hypercalcemia by three genetic mechanisms: inactivating mutations in the calcium-sensing receptor, the G-protein subunit α₁₁, or adaptor-related protein complex 2, sigma 1 subunit. While hypercalcemia in other conditions causes significant morbidity and mortality, FHH generally follows a benign course. Failure to diagnose FHH can result in unwarranted treatment or surgery for the mistaken diagnosis of primary hyperparathyroidism (PHPT), given the significant overlap of biochemical features. Determinations of urinary calcium excretion greatly aid in distinguishing PHPT from FHH, but overlap still exists in certain cases. It is important that 24-h urine calcium and creatinine be included in the initial workup of hypercalcemia. FHH should be considered if low or even low normal urinary calcium levels are found in what is typically an asymptomatic hypercalcemic patient. The calcimimetic cinacalcet has been used to treat hypercalcemia in certain symptomatic causes of FHH.

Bone disease in primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a disease of high bone turnover, decreased bone mineral density (BMD) especially at cortical sites, and increased risk of fractures at all skeletal sites. Early diagnosis during the last decades resulted in milder forms of bone involvement. New methods of imaging and validation such as high resolution peripheral quantitative computed tomography and trabecular bone score provide evidence of disturbed bone microarchitecture and explain further the increased risk of fractures at both cortical and trabecular skeletal sites. Parathyroidectomy has a long-term beneficial effect on the skeleton and is probably prudent to refer PHPT patients for surgery in all cases where increased bone fragility is suspected. Bisphosphonates (BPs), mainly alendronate, have been proved as reasonable choices for BMD improvement while cinacalcet has no effect on bone strength in PHPT. Combination of BPs and cinacalcet, is a valid therapeutic approach from a pathophysiological point of view at least in terms of bone health, however, an adequately powered study to prove it is lacking. Adequate dietary calcium intake and vitamin D supplementation is advised as in the general population for the skeletal integrity of PHPT patients albeit with a close monitoring of serum and urinary calcium levels.

Primary hyperparathyroidism

In this Review, we describe the pathogenesis, diagnosis and management of primary hyperparathyroidism (PHPT), with a focus on recent advances in the field. PHPT is a common endocrine disorder that is characterized by hypercalcaemia and elevated or inappropriately normal serum levels of parathyroid hormone. Most often, the presentation of PHPT is asymptomatic in regions of the world where serum levels of calcium are routinely measured. In addition to mild hypercalcaemia, PHPT can manifest with osteoporosis and hypercalciuria as well as with vertebral fractures and nephrolithiasis, both of which can be asymptomatic. Other clinical forms of PHPT, such as classical disease and normocalcaemic PHPT, are less common. Parathyroidectomy, the only curative treatment for PHPT, is recommended in patients with symptoms and those with asymptomatic disease who are at risk of progression or have subclinical evidence of end-organ sequelae. Parathyroidectomy results in an increase in BMD and a reduction in nephrolithiasis. Various medical therapies can increase BMD or reduce serum levels of calcium, but no single drug can do both. More data are needed regarding the neuropsychological manifestations of PHPT and the pathogenetic mechanisms leading to sporadic PHPT, as well as on risk factors for complications of the disorder. Future work that advances our knowledge in these areas will improve the management of the disorder.

Hyperparathyroidism

Primary hyperparathyroidism is a common endocrine disorder of calcium metabolism characterised by hypercalcaemia and elevated or inappropriately normal concentrations of parathyroid hormone. Almost always, primary hyperparathyroidism is due to a benign overgrowth of parathyroid tissue either as a single gland (80% of cases) or as a multiple gland disorder (15-20% of cases). Primary hyperparathyroidism is generally discovered when asymptomatic but the disease always has the potential to become symptomatic, resulting in bone loss and kidney stones. In countries where biochemical screening tests are not common, symptomatic primary hyperparathyroidism tends to predominate. Another variant of primary hyperparathyroidism has been described in which the serum calcium concentration is within normal range but parathyroid hormone is elevated in the absence of any obvious cause. Primary hyperparathyroidism can be cured by removal of the parathyroid gland or glands but identification of patients who are best advised to have surgery requires consideration of the guidelines that are regularly updated. Recommendations for patients who do not undergo parathyroid surgery include monitoring of serum calcium concentrations and bone density.

Cardiovascular manifestations of primary hyperparathyroidism: a narrative review

Data on cardiovascular disease in primary hyperparathyroidism (PHPT) are controversial; indeed, at present, cardiovascular involvement is not included among the criteria needed for parathyroidectomy. Aim of this narrative review is to analyze the available literature in an effort to better characterize cardiovascular involvement in PHPT. Due to physiological effects of both parathyroid hormone (PTH) and calcium on cardiomyocyte, cardiac conduction system, smooth vascular, endothelial and pancreatic beta cells, a number of data have been published regarding associations between symptomatic and mild PHPT with hypertension, arrhythmias, endothelial dysfunction (an early marker of atherosclerosis), glucose metabolism impairment and metabolic syndrome. However, the results, mainly derived from observational studies, are inconsistent. Furthermore, parathyroidectomy resulted in conflicting outcomes, which may be linked to several potential biases. In particular, differences in the methods utilized for excluding confounding co-existing cardiovascular risk factors together with differences in patient characteristics, with varying degrees of hypercalcemia, may have contributed to these discrepancies. The only meta-analysis carried out in PHPT patients, revealed a positive effect of parathyroidectomy on left ventricular mass index (a predictor of cardiovascular mortality) and more importantly, that the highest pre-operative PTH levels were associated with the greatest improvements. In normocalcemic PHPT, it has been demonstrated that cardiovascular risk factors are almost similar compared to hypercalcemic PHPT, thus strengthening the role of PTH in the cardiovascular involvement. Long-term longitudinal randomized trials are needed to determine the impact of parathyroidectomy on cardiovascular diseases and mortality in PHPT.

Glucocorticoid-responsive lymphocytic parathyroiditis and hypocalciuric hypercalcemia due to autoantibodies against the calcium-sensing receptor: a case report and literature review

OBJECTIVE

Autoimmune lymphocytic parathyroiditis and acquired hypocalciuric hypercalcemia associated with autoantibodies against the calcium-sensing receptor (anti-CaSR) are rare and poorly understood conditions. Here, we describe a patient with acquired parathyroid hormone (PTH)-dependent hypercalcemia with associated hypocalciuria, found to have true lymphocytic parathyroiditis on histopathology, and circulating anti-CaSR antibodies in serum.

DESIGN AND METHODS

A 64-year-old woman was referred to our clinic for persistent hypercalcemia after a subtotal parathyroidectomy. She was normocalcemic until the age of 63 years when she was diagnosed with primary hyperparathyroidism. She underwent subtotal parathyroidectomy with appropriate intraoperative PTH decline. Two weeks post-parathyroidectomy, she presented with persistent hypercalcemia and hyperparathyroidism. Urine studies revealed an inappropriately low 24-h urine calcium (Ca)/creatinine clearance ratio. Surgical pathology was consistent with true lymphocytic parathyroiditis with lymphoid follicles. The presence of circulating anti-CaSR antibodies was detected by immunoprecipitation of CaSR by the patient's serum. After a 4-week course of prednisone, serum Ca and PTH normalized, and her anti-CaSR titers declined. She remains normocalcemic 10 months after the discontinuation of glucocorticoid therapy. We present this patient in the context of the relevant published literature on lymphocytic parathyroiditis and acquired hypocalciuric hypercalcemia related to anti-CaSR antibodies.

CONCLUSIONS

Autoimmune lymphocytic parathyroiditis and acquired hypocalciuric hypercalcemia associated with anti-CaSR antibodies is a very rare yet important condition to be considered in a patient with acquired PTH-dependent hypercalcemia with inappropriate hypocalciuria. Although subtotal parathyroidectomy is unlikely to correct the hypercalcemia, this entity may respond to a short course of prednisone therapy.

Primary hyperparathyroidism: diagnosis and management in 2017

Primary hyperparathyroidism is a relatively common endocrine condition, which is being increasingly identified in its asymptomatic stage, following routine evaluation of serum calcium levels. Parathyroid hormone and calcium excess impact multiple organ systems. The greatest effects are seen on the skeleton and the kidney. This overview describes the current advances in the diagnosis, presentation, and management of primary hyperparathyroidism.

VITAMIN D BINDING PROTEIN AND 25-HYDROXYVITAMIN D LEVELS: EMERGING CLINICAL APPLICATIONS

The precursor of the active form of vitamin D, 25-hydroxyvitamin D (25(OH)D), is recognized as the optimal indicator of vitamin D status. Vitamin D3 undergoes conversion through a multitude of enzymatic reactions described within the paper, and vitamin D levels are dependent on many factors including the vitamin D binding protein (DBP). The free hormone hypothesis postulates that protein-bound hormones are not biologically available and that unbound hormones are biologically active. The majority of circulating 25(OH)D and 1,25-dihydroxyvitamin D is tightly bound to DBP and albumin, with less than 1% circulating in an unbound form. As a result, factors affecting DBP alter the interpretation of 25(OH)D levels. The aim of this review is to assess the current methodology used to measure total and free 25(OH)D, and DBP. Additionally, we analyze the effects of other endocrine hormones and disease processes on DBP levels and subsequently, the interpretation of 25(OH)D levels.

ABBREVIATIONS

CF = cystic fibrosis DBP = vitamin D binding protein ELISA = enzyme-linked immunosorbent assay ESLD = end-stage liver disease HC = hormone contraceptives iPTH = intact parathyroid hormone LC-MS = liquid chromatography-mass spectrometry MS = multiple sclerosis 25(OH)D = 25-hydroxyvitamin D PHPT = primary hyperparathyroidism RIA = radioimmunoassay.

[Diagnostic approach and management of hypercalcaemia in dogs exemplary of primary hyperparathyroidism]

Hypercalcaemia can be caused by many different diseases. This article summarizes the causes, pathophysiologic mechanisms and diagnostic procedures as well as treatment recommendations. The main focus is on hypercalcaemia in primary hyperparathyroidism (PH), complemented by a case report. An elevated total calcium level should generally be investigated and verified by measurement of ionized calcium concentration. The further diagnostic approach depends on the phosphate level. Tumour screening, measurement of parathormone and parathromone-related protein and sonography of parathyroid glands may be necessary. If the calcium-phosphate-product exceeds 60 mg/dl, there is a risk of tissue mineralisation and a rapid treatment of hypercalcaemia is required. For acute therapy, sodium chloride infusion, furosemide and glucocorticoids can be used. Glucocorticoids should only be given after strict indication and after a definite diagnosis. For long-term management, bisphosphates, particularly alendronate, are increasingly used successfully. Causal therapy of PH can be performed by parathyreoidectomy, heat ablation or ethanol ablation. Thereafter, particularly in cases of severe preoperative hypercalcaemia, hypocalcaemia can occur. Treatment is performed using vitamin D₃ (calcitriol), which may also be given preoperatively in cases of severe hypercalcaemia. A concomitant oral calcium supplementation using calcium carbonate as medication of choice is contentious. Due to a potential relapse after successful excision of the affected parathyroid gland in PH, the serum calcium level should be monitored periodically.

[Diagnostic approach and treatment of primary hyperparathyroidism]

- Primary hyperparathyroidism (PHPT) is characterised by elevated serum calcium levels due to elevated levels, or insufficient suppression, of parathyroid hormone (PTH).- The incidence of PHPT has increased in recent years. This is mainly the result of more frequently performed routine measurements of serum calcium, e.g. as part of postmenopausal screening.- The classically described features of PHPT - bones and stones - are not always observed and most patients are asymptomatic.- Diagnosis of PHPT is only established by biochemical testing, not by imaging.- Ultrasound and technetium-99m sestamibi SPECT-CT are the first-choice imaging modalities. These investigations are necessary to localize the parathyroid adenomas and thereby facilitate minimal invasive parathyroidectomy (MIP).

Primary hyperparathyroidism: review and recommendations on evaluation, diagnosis, and management. A Canadian and international consensus

The purpose of this review is to assess the most recent evidence in the management of primary hyperparathyroidism (PHPT) and provide updated recommendations for its evaluation, diagnosis and treatment. A Medline search of "Hyperparathyroidism. Primary" was conducted and the literature with the highest levels of evidence were reviewed and used to formulate recommendations. PHPT is a common endocrine disorder usually discovered by routine biochemical screening. PHPT is defined as hypercalcemia with increased or inappropriately normal plasma parathyroid hormone (PTH). It is most commonly seen after the age of 50 years, with women predominating by three to fourfold. In countries with routine multichannel screening, PHPT is identified earlier and may be asymptomatic. Where biochemical testing is not routine, PHPT is more likely to present with skeletal complications, or nephrolithiasis. Parathyroidectomy (PTx) is indicated for those with symptomatic disease. For asymptomatic patients, recent guidelines have recommended criteria for surgery, however PTx can also be considered in those who do not meet criteria, and prefer surgery. Non-surgical therapies are available when surgery is not appropriate. This review presents the current state of the art in the diagnosis and management of PHPT and updates the Canadian Position paper on PHPT. An overview of the impact of PHPT on the skeleton and other target organs is presented with international consensus. Differences in the international presentation of this condition are also summarized.

[Etiology and pathogenesis of primary hyperparathyroidism.]

Primary hyperparathyroidism(pHPT)is a frequent endocrine disease in which abnormal calcium(Ca)regulation leads to hypercalcemia. The most frequent cause of pHPT in more than 80% of patients is an adenoma, followed by hyperplasia in about 15%, and cancer in 1~5%. Although most cases of pHPT are sporadic, a few are familial(hereditary), and this is known as familial hyperparathyroidism(FHPT). Gene abnormalities that affect cyclin D1 signaling(CCND1, CDC73, CDKN1B), Wnt/β-catenin signaling(MEN1), and calcium-sensing receptor signaling(CaSR, GNA11, AP2S1)play a role in the etiology and pathogenesis of pHPT. Vitamin D insufficiency/deficiency and CaSR dysfunction also play a role in pHPT severity. Continued elucidation of the etiology and pathogenesis of pHPT may lead to development of new treatments for pHPT as well as further understanding of Ca regulation.

[Surgical and non-surgical management of primary hyperparathyroidism:How do calcimimetics work?]

Primary hyperparathyroidism is a common endocrine disease. The first line therapy for the disease is surgical removal of affected parathyroid gland(s). Other therapeutic options with medication are needed to be established, because many of patients with primary hyperparathyroidism have few or no symptoms and are expected to have a long life expectancy without surgery. Cinacalcet as a calcimimetic, bisphosphonates and denosumab are promising candidates for medical management of the disease. Effectiveness and efficiency of these drugs for patients with primary hyperparathyroidism is to be evaluated in comparison with surgical treatment.