Subclinical and asymptomatic parathyroid disease: implications of emerging data

Assessment of Vitamin D Status in Primary Hyperparathyroidism Patients: A Retrospective Study

BACKGROUND

Primary hyperparathyroidism (PHPT), a condition that manifests in various clinical forms, is a significant health concern. Normocalcemic primary hyperparathyroidism (NPHPT) is characterized by normal calcemia despite elevated parathyroid hormone (PTH) levels. Vitamin D deficiency can contribute to the clinical spectrum and complexity of NPHPT. Low vitamin D levels can elevate PTH, making it difficult to distinguish between NPHPT and secondary hyperparathyroidism. Additionally, it might mask hypercalcemia, leading to an underestimation of the disease severity. Our study aims to shed light on these complexities by investigating normocalcemic and hypercalcemic PHPT patient's clinical, hormonal, and biochemical patterns, including their vitamin D status.    Materials: In this retrospective study, we enrolled 60 PHPT patients with autonomous parathyroid function confirmed using a combination of ultrasonography, radionuclide scan, and parathyroid function index calculation. We evaluated the albumin-corrected calcemia, calciuria, PTH, 25(OH)D level, serum phosphate, bone mineral density, and major clinical symptoms (fracture, nephrolithiasis). A comparative analysis and a correlation study were performed between normo- and hypercalcemic and vitamin D-deficient and vitamin D-non-deficient groups.

RESULTS

 The median age was 62 years, 51.66% (31/60) being normocalcemic and 46.66% (29/60) presenting a deficient 25(OH)D level. In the group with 25(OH)D below 20 ng/mL, we observed a reduced level of albumin-corrected calcemia, without a significant increase of PTH compared to the adequate 25(OH)D level group. The frequency of the NPHPT and the risk of fracture were significantly higher in the deficient 25(OH)D group (20/60, 33.33% and 8/60, 13.33%) than in the adequate one (11/60, 18.33% and 1/60, 1.66%) with OR=4.7 (p<0.004) and OR=9.7 (p<0.027), respectively. We also found a positive correlation between PTH and adenoma size, the parathyroid function index and adenoma size, as well as PTH and phosphate levels. However, the correlation between 25(OH)D and phosphate levels was negative and moderate (rho=-0.504, p<0.001), adding a new layer of complexity to our understanding of these relationships.

CONCLUSION

Our study provided significant insight into the link between vitamin D status and normocalcemic PHPT. We found that vitamin D-deficient patients with normocalcemic PHPT have an increased fracture risk, which requires meticulous monitoring and possible supplementation with vitamin D. This should be done carefully to avoid exacerbating hypercalcemia or hypercalciuria. Further research is needed to refine these management strategies and deepen our understanding of the complex relationships between the analyzed parameters.

Brown tumor due to primary hyperparathyroidism in a familial case: a case report

BACKGROUND

Primary hyperparathyroidism (PHPT) is an uncommon disorder characterised by hypercalcemia with an increased parathyroid hormone level. We reported a PHPT familial case with two subjects, a father and a daughter, and both of them had suffered from the brown tumor.

CASE PRESENTATION

The proband, a 43-year-old patient, developed parathyroid adenomas at the age of 15; a histologically confirmed right parathyroid adenoma was removed by parathyroidectomy; and after six months follow-up, the serum calcium level was normalised. At the age of thirty-three, a CT scan of his head and neck revealed a mass in the right maxilla, as well as PHPT (i.e., left inferior parathyroid adenoma). Then, he underwent a biopsy of an exophytic lesion in the right maxilla and was diagnosed by pathology as a brown tumor, with the serum calcium and PTH levels at 2.78 mmol/L and 221 pg/mL, respectively. Subsequently, the patient took a left inferior parathyroid microwave ablation with ultrasound guidance. After three months of follow-up, the serum calcium and PTH levels returned to normal, and the brown tumor was resolved. After three years, it mineralised as revealed in a CT scan. By the time he was 43 years old, during the 28-year follow-up period, the serum calcium and PTH levels were still within the normal range, and there was no discomfort reported. He has consistently taken calcium supplements throughout the 28 years. Since the initial diagnosis, his blood indicators of kidney function have been normal, and ultrasound showed renal calculus in the right kidney and a normal left kidney. The proband's daughter, a 15-year-old girl, experienced left upper extremity pain for ten months. CT scan revealed a mass in the distal left radius, and a giant cell tumor was suspected. A surgical internal fixation was performed, and the pathology showed a brown tumor. Laboratory tests revealed a serum parathyroid hormone (PTH) level of 1554pg/mL, calcium level of 3.14 mmol/L, phosphorus level of 0.72 mmol/L, and alkaline phosphatase level of 1892 U/L. Given the osteitic changes and elevated levels of calcium and PTH, ultrasonography was performed, after which a mass was detected measuring 19 × 9 × 7 mm mixed with solid components and cystic fluid in the right thyroid gland. The results of 99mTc-MIBI scintigraphy confirmed the abnormal accumulation of 99mTc-MIBI in the right thyroid gland but not seen in the bilateral parathyroid glands. The patient underwent thyroidectomy, and the postoperative pathology report indicated an intra-thyroid ectopic parathyroid adenoma. The serum calcium and PTH levels became normal at 4 h after surgery. One to three months after operation, the serum calcium level was low, while the serum PTH level was high. Then, the patient was advised to take calcium supplements. Until the sixth month after the operation, the serum calcium level and serum PTH level returned to normal, and the bone pain was relieved. The patient's blood tests for kidney function remained normal. There was no evidence of bilateral kidney disease (such as nephrolithiasis or nephrocalcinosis) detected by ultrasound scan. There were several similarities in the state of illness between these two subjects. Both the father and the daughter developed parathyroid adenomas at the age of 15, and there was no lesion in other endocrine glands. And genetic testing revealed mutations in the CDC73 genes in both father and daughter. On the other hand, there were also a few differences. The father's first signs of brown tumor were in the right maxilla, while the daughter's appeared in the distal left radius. The father presented pathological changes in the left and right parathyroid glands, whereas the daughter presented with an ectopic parathyroid adenoma in the right thyroid gland.

CONCLUSION

We report a familial case in which father and daughter were diagnosed to have brown tumors due to parathyroid adenoma and ectopic parathyroid adenoma, and genetic testing revealed CDC73 gene mutations in both. Therefore, in the diagnostic and differential process of young patients having bone disease, clinicians should not only focus on the clinical manifestations of the skeleton, but also implement a comprehensive analysis of systemic symptoms, considering the possibility that the patient has familial PHPT.

Morbidity Associated With Primary Hyperparathyroidism-A Population-based Study With a Subanalysis on Vitamin D

CONTEXT

Primary hyperparathyroidism (PHPT) is associated with increased risk of morbidity and death, and vitamin D levels are a potentially confounding variable.

OBJECTIVE

The aim of this study was to assess morbidity and mortality associated with primary hyperparathyroidism (PHPT).

METHODS

In this population-based retrospective matched cohort study, data linkage of biochemistry, hospital admissions, prescribing, imaging, pathology, and deaths was used to identify patients across the region of Tayside, Scotland, who had PHPT from 1997 to 2019. Cox proportional hazards models and hazards ratios (HR) were used to explore the relationship between exposure to PHPT and several clinical outcomes. Comparisons were made with an age- and gender-matched cohort.

RESULTS

In 11 616 people with PHPT (66.8% female), with a mean follow-up period of 8.8 years, there was an adjusted HR of death of 2.05 (95% CI, 1.97-2.13) for those exposed to PHPT. There was also an increased risk of cardiovascular disease (HR = 1.34; 95% CI, 1.24-1.45), cerebrovascular disease (HR = 1.29; 95% CI, 1.15-1.45), diabetes (HR = 1.39; 95% CI, 1.26-1.54), renal stones (HR = 3.02; 95% CI, 2.19-4.17) and osteoporosis (HR = 1.31; 95% CI, 1.16-1.49). Following adjustment for serum vitamin D concentrations (n = 2748), increased risks for death, diabetes, renal stones, and osteoporosis persisted, but not for cardiovascular or cerebrovascular disease.

CONCLUSION

In a large population-based study, PHPT was associated with death, diabetes, renal stones, and osteoporosis, independent of serum vitamin D concentration.

Comparison of Medical Management versus Parathyroidectomy in Patients with Mild Primary Hyperparathyroidism: A Meta-Analysis

BACKGROUND

Parathyroidectomy is the definitive cure for patients with primary hyperparathyroidism (pHPT) and has an annual prevalence of 0.2-1% in the United States. Some patients with mild disease are medically managed effectively using calcium-lowering medications and drugs against complications such as osteoporosis; however, many maintain a persistently high calcium level that negatively impacts their skeletal, renal, and psychogenic systems over the long term. This meta-analysis aims to compare the outcomes of medical management versus parathyroidectomy in patients with mild pHPT.

STUDY DESIGN

This meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using PubMed, Embase, and Web of Science by two teams of investigators. Analysis was run using R packages.

RESULTS

A total of 12 publications including seven randomized control, two prospective, and three retrospective trials with a total of 1346 patients were included for analysis. The average follow-up for all patients was 41 ± 23.8 months. Demographics, pre-treatment calcium, PTH, and bone mineral density (BMD) were similar between the medical (N = 632) and surgical (N = 714) cohorts. Post-treatment calcium and PTH levels were significantly higher in the medical cohort (10.46 vs. 9.39, p < 0.01), (106.14 vs. 43.25, p = 0.001), respectively. Interestingly, the post-treatment PTH in the medical cohort increased when compared to pre-treatment (83.84 to 106.14). Patients in the medical cohort had lower BMD in lumbar (0.48 g/cm²; OR = 0.42, 95% CI = 0.21, 0.83), femoral (0.48; OR = 0.42, 95% CI = 0.29, 0.61), and hip (0.61; OR = 0.33, 95% CI = 0.13, 0.85). Incidences of fracture, nephrolithiasis, cardiovascular death, or overall mortality were not significantly different between the cohorts.

CONCLUSIONS

The present study is the most comprehensive meta-analysis on mild pHPT to date. Our findings reflect that parathyroidectomy is the superior option in the treatment of mild pHPT patients as opposed to medical management.

The Calcium Loading Test in Primary Hyperparathyroidism – Does it Provide Useful Information?

Objective: to describe the results from intravenous calcium loads in patients with suspected PHPT.

Methods: This was a retrospective cross-sectional study with inpatients’ data review. Baseline serum calcium, phosphates, magnesium, creatinine, alkaline phosphatase, beta-crosslinks were recorded. The calcium loading had been performed after an overnight fasting. Calcium gluconate 0.25 mmol/kg body weight (10 mg/kg) dissolved in 0.9% Sodium Chloride was infused intravenously for 3 hours. Blood samples for total serum calcium, phosphates and iPTH were drawn before and up to 60 minutes after the calcium load. The intact parathyroid hormone (iPTH) and 25(OH)-vitamin D were determined by electro-hemi-luminescence (Elecsys, Roche Diagnostics). The PTH inhibition rate in % (PTH-IR), the calcium increment, the ratio R (ΔPTH/ΔCalcium) and the product P (calcium X PTH at test end) were calculated.

Results: 23 patients with PHPT had complete data from calcium loading tests. The PTH suppression was < 30% in 17.4% of the participants, 30% to 50% – in 21.7% and > 50% in the remaining 60.9%. One patient displayed PTH suppression > 75%. The Ratio R was < 4.0 in all but one patient. Product P was above 1100 mg/dl x pg/ml in 9 participants (39.1%). Sixteen patients (69.6%) had positive localization results from US or SPECT-CT. The level of PTH suppression was not related to any parameter except the volume of the suspected lesion.

Conclusion: The calcium loading test was unable to differentiate the forms of PHPT. It did not add great value in the diagnostic work-up of PHPT.

Parathyroid Hormone Disturbances in Postmenopausal Women with Distal Forearm Fracture

Background

Primary hyperparathyroidism (PHPT) is a common endocrine disorder with a wide range of adverse effects, such as osteoporosis. Many women are not diagnosed due to asymptomatic disease or vague symptoms but are still at risk of severe adverse effects. Early identification of patients with PHPT is therefore of importance. The aim of this study was to determine PHPT prevalence among postmenopausal women with a distal forearm fracture.

Methods

Recruitment was conducted in conjunction with the occurrence of a distal forearm fracture at Karolinska University Hospital. In total, 161 postmenopausal women were included in a cross-sectional study with repeated evaluations. Analyzes of serum calcium, ionized calcium, phosphate, parathyroid hormone (PTH), and vitamin D were performed. Diagnosis of PHPT was based on clinical evaluations and biochemical definitions of serum calcium and PTH in coherence with previous population prevalence reports.

Results

Mean age was 64.7 (9.5) years, serum calcium 2.33 (0.10) mmol/L, ionized calcium 1.25 (0.05) mmol/L and PTH 54 (26) ng/L. PTH was elevated in 32 (20%) women. In total, 11 (6.8%) women were diagnosed with PHPT; 6 with classical PHPT and 5 with mild PHPT. The prevalence of PHPT was significantly increased compared to the population prevalence of 3.4% (p = 0.022).

Conclusion

Screening postmenopausal women in conjunction with low-energy distal forearm fracture revealed a large number of women with parathyroid disturbance. Evaluation of parathyroid hormone and calcium status in this group of patients seems beneficial.

Primary Hyperparathyroidism – A Contemporary Picture Based on 100 Patients from the Last Decade

Primary hyperparathyroidism (PHPT) is an endocrine disease, the clinical picture of which has slowly shifted to milder and asymptomatic forms during the last decades.

Objective

to describe the clinical presentation and the main laboratory and imaging findings in a group of patients with PHPT diagnosed during the last 10 years.

Materials and Methods

This was a retrospective cross-sectional study with data review from the database of a tertiary endocrine clinic from the last 10 years. Secondary causes for elevated PTH were excluded. The major clinical symptoms and signs of hypercalcemia/HPT were reviewed as well as concomitant diseases and medications. Serum calcium (total, albumin-corrected and ionized; sCa, corrCa, iCa+), phosphates (P), magnesium, creatinine, alkaline phosphatase, beta-crosslinks were measured. The intact parathyroid hormone (iPTH) and 25(OH)-vitamin D were determined by electro-hemi-luminescence (Elecsys, Roche Diagnostics). 24-hour urinary probes for calcium and phosphate were collected. Neck ultrasound (US) was used as the localization study of choice. Almost half of the participants underwent fine-needle aspiration biopsy (FNAB) with cytology and needle-washouts for iPTH. One fourth of the patients were assessed by Single-Photon Emission Tomography (SPECT-CT). Data on bone density (from DXA), fractures and renal stones (from renal US) were collected.

Results

One hundred patients met the study criteria – 95 were women. Most of them were in their 5th and 6th decades. The median corrected sCa was 2.73 mmol/l, iCa+ – 1.39 mmol/l, P – 0.88 mmol/l, iPTH – 14.5 pmol/l and 25(OH)D – 54.0 nmol/l. Normal sCa was registered in 20 participants (20%), while normal sP – in 67.0%. The neck US located single lesions (parathyroid adenoma) in 81% – behind or below the left inferior pole of the thyroid gland in 33 cases (33%) and contra-laterally in another 33%. FNAB of the suspicious lesion had been performed in 51% of the study subjects. The cytology confirmed the presence of parathyroid cells in 22 cases (43.1%), Bethesda II thyroid nodules in 21 cases (41.2%), Bethesda III nodules in 2 cases (3.9%) and insufficient samples (Bethesda I) in 5 cases (9.8%). SPECT-CT from 27 patients identified a suspicious left parathyroid in 11 cases, a right one – in 6 cases, as well as three ectopic locations. BMD data were available in 66 female patients and showed a higher prevalence of osteoporosis than in the general age-matched population; fractures, however, were not more frequent. Data from renal ultrasound were available in 77% and revealed chronic pyelonephritis without stones in 8 patients and renal stone disease – in 37 patients.

Conclusion

To our knowledge, this study is the first of its kind in our country during the last two decades. Mild to moderate hypercalcemia was very common, although most patients were oligoor asymptomatic. Renal and bone involvement were surprisingly frequent, with reduced eGFR and low bone mass being more prevalent than in the general population. The most typical location was a single parathyroid lesion within the lower glands. The use of SPECT-CT seems to decline and is replaced by US-guided FNAB with needle washout measurements of iPTH and cytological examination. Although the general picture of PHPT is shifting towards milder and asymptomatic (and probably earlier) forms of the disease, the classical clinical presentation can still be found in everyday practice.

Serum magnesium, bone-mineral metabolism markers and their interactions with kidney function on subsequent risk of peripheral artery disease: the Atherosclerosis Risk in Communities Study

BACKGROUND

Few studies have investigated the association of magnesium levels with incident peripheral artery disease (PAD) despite emerging evidence of magnesium contributing to vascular calcification. Moreover, no data are available on whether the magnesium-PAD relationship is independent of or modified by kidney function.

METHODS

A cohort of 11 839 participants free of PAD in the Atherosclerosis Risk in Communities Study at Visit 2 (1990-92) was studied. We investigated the association of serum magnesium and other bone-mineral metabolism markers [calcium, phosphorus, intact parathyroid hormone (iPTH) and intact fibroblast growth factor-23] with incident PAD using multivariable Cox proportional hazards regression.

RESULTS

Over a median of 23 years, there were 471 cases of incident PAD. The hazard ratio for incident PAD in Quartile 1 (<1.5 mEq/L) versus Quartile 4 (>1.7 mEq/L) of magnesium was 1.96 (95% confidence interval 1.40-2.74) after adjustment for potential confounders. Lower magnesium levels were associated with greater incidence of PAD, particularly in those with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 (n = 11 606). In contrast, the association was largely flat in those with eGFR <60 mL/min/1.73 m2 (n = 233) with P-for-interaction 0.03. Among bone-mineral metabolism markers, only higher iPTH showed an interaction with kidney function (P-for-interaction 0.01) and iPTH >65 pg/mL was significantly related to PAD only in those with eGFR <60 mL/min/1.73 m2.

CONCLUSIONS

Lower magnesium was independently associated with incident PAD, but this association was significantly weaker in those with reduced kidney function. In contrast, higher iPTH levels were particularly related to PAD risk in this clinical population.

Parathyroid Imaging

Primary hyperparathyroidism (PHPT) is a common endocrine abnormality, caused in most cases by a single parathyroid adenoma. Surgery remains the first-line curative therapy in PHPT. Imaging plays a vital role in presurgical localization of parathyroid adenomas. Ultrasound provides a safe and quick imaging modality free of ionizing radiation, but is operator dependent. Sestamibi scan offers comparable sensitivity to ultrasound, improved with concurrent tomographic imaging. 4DCT remains a problem-solving technique in challenging cases and after failed neck exploration. We present an overview of various parathyroid imaging modalities, including protocols and findings, in addition to relevant pearls and pitfalls.

Association between neutrophil-to-lymphocyte ratio and parathyroid hormone in patients with primary hyperparathyroidism

INTRODUCTION

Primary hyperparathyroidism (PHPT) is associated with adverse cardiovascular outcomes which may result from an increase in systemic inflammation. Previously we have shown that serum parathyroid hormone (PTH) levels are independently associated with inflammatory indicators. The neutrophil-to-lymphocyte ratio (NLR) is an inexpensive, widely available marker of inflammation. In the present study, we aimed to assess the longitudinal changes in NLR before and after parathyroidectomy.

MATERIAL AND METHODS

This retrospective study included 95 patients diagnosed with PHPT who underwent parathyroidectomy between 2006 and 2016. Follow-up complete blood counts were available in 31 patients.

RESULTS

At diagnosis, 43 (45%) patients presented with overt clinical symptoms and had higher serum calcium and PTH levels. Preoperative NLR was positively correlated with total white blood cell count (p = 0.001), serum calcium (p = 0.001), and PTH level (p = 0.013). The NLR was not associated with sex, age, comorbidities, or parathyroid weight. Among patients who were cured of PHPT, the median NLR decreased from 2.26 to 1.77 after parathyroidectomy (p = 0.037). There was no difference in hemoglobin, total white blood cells, or platelet count before and after surgery.

CONCLUSIONS

We found a positive correlation of preoperative NLR with calcium and PTH levels in PHPT patients. After curative parathyroidectomy, NLR modestly decreased without changes in other hematological parameters.

Primary hyperparathyroidism due to ectopic parathyroid adenoma in an adolescent: a case report and review of the literature

PURPOSE

Primary hyperparathyroidism (PHPT) is a common endocrine disorder and is usually diagnosed in adults. PHPT due to ectopic parathyroid adenoma in adolescents is rare.

METHODS

We describe the case of a 15-year-old boy with PHPT due to ectopic parathyroid adenoma. A review of the literature of PHPT in adolescents was performed, focusing on etiology, clinical presentation, preoperative localization methods, pathology, and treatment.

RESULTS

The patient was successfully treated with surgery and was followed up for 5 years with no signs or symptoms of hyperparathyroidism. By reviewing the literature, only seven cases of PHPT associated with ectopic parathyroid lesions in adolescents have been reported. Parathyroidectomy is the only known curative treatment. Accurate preoperative localization of the target lesion is critical.

CONCLUSIONS

This study should raise awareness of the diagnosis and treatment of PHPT due to ectopic parathyroid adenoma/carcinoma in adolescents.

Parathyroid Hormone Causes Endothelial Dysfunction by Inducing Mitochondrial ROS and Specific Oxidative Signal Transduction Modifications

Vitamin D deficiency contributes to cardiovascular risk (CVR), with hyperparathyroidism advocated as a putative mechanism. Indeed, mounting evidence supports the hypothesis that parathyroid hormone (PTH) impairs endothelial function, even though mechanisms are not fully elucidated. The present study was designed to verify in vitro the ability of sustained exposure to PTH to cause endothelial dysfunction, exploring the underlying mechanisms. In bovine aortic endothelial cells (BAECs), we evaluated the effects of PTH exposure (0.1 nM–24 hours) on both endothelial response to vasodilators, such as bradykinin (Bk (30 nM)) and acetylcholine (Ach (1 μM)), and angiogenic competence. Pretreatment with PTH impaired endothelial response to Bk but not to Ach, in terms of cytosolic calcium fluxes and NO production. In order to explore the underlying mechanisms, we assessed the production of total and mitochondrial ROS (tROS and mROS, respectively) in response to PTH (at 1 and 3 hours). PTH increased ROS generation, to an extent high enough to determine oxidation of Bk receptor B2. Conversely, the oxidation levels of M1 and M3 Ach receptors were not affected by PTH. A mROS selective scavenger (MitoTEMPO (5 μM)) restored the endothelial responsiveness to Bk while the well-known antioxidant properties of vitamin D (100 nM) failed to counteract PTH-mediated oxidative stress. PTH determined mitochondrial calcium fluxes ([Ca²⁺]_mt) and the mitochondrial calcium uniporter inhibitor Ru360 (10 μM) reduced mROS production and prevented the PTH-mediated endothelial dysfunction. Angiogenic competence was evaluated as tubular formations in the endothelial Matrigel assay and showed a significant impairment in PTH-pretreated cells (0.1 nM–24 hours), despite the increase in VEGF transcriptional levels. VEGFR2 oxidation occurred in response to PTH, suggesting that even the impairment of angiogenesis was due to the ROS surge. These results indicate that PTH affects endothelial function through ROS production, driven by mitochondrial calcium overload. PTH-induced oxidative stress might act as signaling modifiers, altering specific pathways (Bk and VEGF) and preserving others (Ach).

Normocalcaemic primary hyperparathyroidism: a pragmatic approach

It is well recognised that over the past three to four decades the incidence of asymptomatic primary hyperparathyroidism has increased significantly. However, more recently this pattern has further evolved into a presentation with normocalcaemia and raised parathyroid hormone (PTH) level without the presence of a recognised stimulus for its rise, in the form of vitamin D deficiency or renal impairment. A diagnostic label of normocalcaemic hyperparathyroidism (NPHPT) has been given to this phenotype and in most such individuals, the initial PTH measurement is driven by the presence of metabolic bone disease. The reported prevalence, degree of end-organ involvement and the rate of progression vary considerably and are related to patients studied and the biochemical cut-offs used in its definition. A majority of patients are diagnosed during assessment of metabolic bone disease of varying degrees. Once the diagnosis is confirmed by excluding confounding factors, the patient should undergo full assessment of end-organ involvement, which is the main determinant of further therapeutic decisions. Surgery, with prior localisation, is considered in patients with significant end-organ involvement in keeping with the guidance for hypercalcaemic patients. If a patient does not meet these criteria, annual clinical and biochemical surveillance is recommended to identify progression to hypercalcaemia or worsening end-organ involvement. It is less clear if patients identified during 'routine' requests for evaluation of unrelated symptoms require similar close monitoring. In conclusion, in this review on NPHPT we focus on its definition, planning of further investigations, selection of patients for intervention and devising an appropriate follow-up strategy.

Current opinions on nephrolithiasis associated with primary hyperparathyroidism

Nephrolithiasis is a common urological disease and could be secondary to primary hyperparathyroidism (PHPT). PHPT is traditionally characterised with hypercalcaemia. Recently, a normocalcemic PHPT has been officially recognised at the International Workshops. Regarding this new phenotype, nephrolithiasis is frequently found in studies that evaluate low bone mass. However, until now, no study on aetiology of nephrolithiasis considered normocalcemic PHPT. Hypercalciuria related to PHPT is considered as an important risk factor of stone formation in hypercalcemic PHPT, but the precise relationships between hypercalcemic PHPT and nephrolithiasis and between normocalcemic PHPT and nephrolithiasis remain unclear. In patients with hypercalcemic PHPT, after a surgical cure of PHPT, the renal calcium excretion and stone recurrence rate reduce but remain higher above health controls. This finding implies that abnormalities not caused by PHPT also probably affect stone formation. According to the new guideline, the presence of stones indicates the need for parathyroidectomy in patients with either hypercalcemic or normocalcemic PHPT unless contraindications exist. Patients with contraindications for parathyroidectomy or those who do not want to receive parathyroidectomy should be monitored for signs of disease progression and given of medical management. Moreover, due to decreased but significantly higher frequency of nephrolithiasis above those of healthy controls, patients with nephrolithiasis associated with PHPT after parathyroidectomy still should be motivated to explore strategies to prevent stone occurrence.

Evaluation of acute and chronic MRI features of sacroiliitis in asymptomatic primary hyperparathyroid patients

Asymptomatic primary hyperparathyroidism (PHPT) is characterized with autonomous overproduction of parathyroid hormone without signs or symptoms associated with hyperparathyroidism. Before symptoms become obvious, PHPT may affect structures like sacroiliac joints, which consist of bone. So, in the asymptomatic PHPT patients, structural and inflammatory changes in sacroiliac joints may lead to confusion during diagnosis workup of axial spondyloarthropathy. In this study, we evaluated active and chronic sacroiliac magnetic resonance imaging (MRI) changes relevant to sacroiliitis in the patients with asymptomatic PHPT and interpreted bone marrow edema within the scope of Assessment of SpondyloArthritis International Society-Outcome Measures in Rheumatology Clinical Trials (ASAS-OMERACT) criteria. Forty-nine patients with asymptomatic PHPT, 26 patients with newly diagnosed axial spondyloarthropathy (SpA), and 37 healthy controls were enrolled. All subjects were evaluated by sacroiliac MRI for four active (bone marrow edema, enthesitis, capsulitis, and synovitis) and four chronic (subchondral sclerosis, subchondral/periarticular erosions, periarticular fat deposition, and bony bridges/ankylosis) lesions relevant to sacroiliitis. Bone marrow edema compatible with ASAS-OMERACT active sacroiliitis criteria in sacroiliac MRI was fulfilled by 16.3 % (8/49) of the asymptomatic PHPT patients which was similar with controls but statistically lower than axial SpA. Moreover, asymptomatic PHPT patients and controls were similar for other chronic or active MRI findings. Also, we detected lower frequency of all other MRI findings, except enthesis, in asymptomatic PHPT patients according to axial SpA. Acute inflammatory including bone marrow edema fulfilling ASAS-OMERACT active sacroiliitis criteria and chronic structural sacroiliac lesions relevant to sacroiliitis in MRI were detected in asymptomatic PHPT similar frequency with controls but as expected, lower than axial SpA. But, these findings could not be attributed to excessive secretion of parathyroid hormone.

Robotic transaxillary and retroauricular parathyroid surgery

Current advancement in robotic surgery has provided a safe, precise, 3-dimensional (3D) magnified dissection for parathyroid surgery without the need for CO2 insufflation, and with a better cosmetic outcome due to an invisible scar in the axillary or retroauricular region. Preoperative imaging studies that assist in the localization of lesions have been key elements in patients' selection for targeted parathyroid surgery.

Clinicopathological correlates of hyperparathyroidism

Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.

Is surgery necessary for 'mild' or 'asymptomatic' hyperparathyroidism?

A large majority of the currently diagnosed patients with hyperparathyroidism (PHPT) are mild or asymptomatic, mainly women after menopause. Following the debate held at the 16th European Congress of Endocrinology in Wroclaw (Poland) from May 3-7, 2014, arguments are here presented by a surgeon and a medical practitioner considering these situations rather have to profit from surgery, or simply from survey. For the trained endocrine surgeon, it is evident that parathyroidectomy confirms the diagnosis and undoubtedly reduces the discomfort felt by certain patients, prevents all risks of complications, removes patients and medical teams from the monitoring and represents a real individual financial benefit. On the other hand, the medical practitioner considers that mild or asymptomatic PHPT is commonly stable, and very rare are the subjects at risk of complications, particularly of fractures; prevention of vascular and metabolic disorders, nephrolithiasis and bone rarefaction justify regular physical exercise, a safe alimentation, a sufficient calcium and high water intake, the correction of the frequent deficit in vitamin D; finally has also to be considered the impossibility to refer to specialized (endocrine) surgeons, the enormous cohort of subjects more than 50 years with 'mild' or 'asymptomatic' PHPT. The surgeon and the medical practitioner agree to consider that in patients with 'mild' or 'asymptomatic' disease, there is no place for medical treatments, in particular calcimimetics and bisphophonates. Both agree that further studies are needed to clarify the long-term prognosis of operated and non-operated PHPT in term of fractures, cardiovascular risk and mortality. Individual and collective cost/benefit ratios of surgery or survey are also still imperfectly evaluated.

Progress in aldosteronism: a review of the prevalence of primary aldosteronism in pre-hypertension and hypertension

Primary aldosteronism (PA) secondary to excessive and/or autonomous aldosterone secretion from the renin-angiotensin system accounts for ∼10% of cases of hypertension and is primarily caused by bilateral adrenal hyperplasia (BAH) or aldosterone-producing adenomas (APAs). Although the diagnosis has traditionally been supported by low serum potassium levels, normokalaemic and even normotensive forms of PA have been identified expanding further the clinical phenotype. Moreover, recent evidence has shown that serum aldosterone correlates with increased blood pressure (BP) in the general population and even moderately raised aldosterone levels are linked to increased cardiovascular morbidity and mortality. In addition, aldosterone antagonists are effective in BP control even in patients without evidence of dysregulated aldosterone secretion. These findings indicate a higher prevalence of aldosterone excess among hypertensive patients than previously considered that could be attributed to disease heterogeneity, aldosterone level fluctuations related to an ACTH effect or inadequate sensitivity of current diagnostic means to identify apparent aldosterone excess. In addition, functioning aberrant receptors expressed in the adrenal tissue have been found in a subset of PA cases that could also be related to its pathogenesis. Recently a number of specific genetic alterations, mainly involving ion homeostasis across the membrane of zona glomerulosa, have been detected in ∼50% of patients with APAs. Although specific genotype/phenotype correlations have not been clearly identified, differential expression of these genetic alterations could also account for the wide clinical phenotype, variations in disease prevalence and performance of diagnostic tests. In the present review, we critically analyse the current means used to diagnose PA along with the role that ACTH, aberrant receptor expression and genetic alterations may exert, and provide evidence for an increased prevalence of aldosterone dysregulation in patients with essential hypertension and pre-hypertension.

Primary hyperparathyroidism and vitamin D deficiency

Primary hyperparathyroidism (PHPT) and vitamin D (VD) deficiency are frequent conditions due to the widespread application of assays for calcium and VD. PHPT presentation is dominated by diversity in its expression and the current predominance of asymptomatic forms. VD, which plays a major role in calcium and phosphate homeostasis, is also involved in many physiological processes in this disease, such as lipid and glucose metabolism, and in the signalling pathways and functioning of many cell types. The bone and cardiometabolic complications described in PHPT are exacerbated by vitamin D deficiency, the prevalence of which varies according to many parameters (environment, skin pigmentation, associated chronic diseases, liver and kidney function, assay kit used, etc.). In response to this observation, experts in field from medical societies validated the indication for systematic assay of VD occurring with PHPT and the need for replacement in case of deficiency. Several epidemiological studies have confirmed that replacement with natural vitamin D is well tolerated and safe in subjects with PHPT and VD deficiency. This supplementation reduces hyperparathormonemia, does not have symptomatic effects on calciuria, and especially improves the bone and functional condition of patients.