Normocalcemic primary hyperparathyroidism: a survey in a small village of Southern Italy

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.

The Eucalcemic Patient With Elevated Parathyroid Hormone Levels

Primary hyperparathyroidism (PHPT) is classically characterized by hypercalcemia with elevated or inappropriately normal parathyroid hormone (PTH) levels. Elevated PTH levels in the presence of normal calcium levels are not infrequently found during the evaluation of metabolic bone disorders or kidney stone disease. This can be caused by secondary hyperparathyroidism (SHPT) or normocalcemic primary hyperparathyroidism (NPHPT). NPHPT is due to autonomous parathyroid function whereas SHPT is caused by a physiologic stimulation to PTH secretion. Many medical conditions and medications can contribute to SHPT, and differentiation between SHPT and NPHPT may be difficult. Cases are presented to illustrate examples. In this paper, we review the distinction between SHPT and NPHPT as well as end organ effects of NPHPT and outcomes of surgery in NPHPT. We suggest that the diagnosis of NPHPT be made only after careful exclusion of causes of SHPT and consideration of medications that can increase PTH secretion. Further, we advise a conservative approach to surgery in NPHPT.

Comparison of 4D computed tomography and F-18 fluorocholine PET for localisation of parathyroid lesions in primary hyperparathyroidism: A systematic review and meta-analysis

Minimally invasive parathyroidectomy (MIP) is the standard of care for primary hyperparathyroidism (PHPT). Four dimensional computed tomography(4DCT) and F-18 Fluorocholine positron emission tomography/computed tomography (FCH PET/CT) localize adenomas accurately to perform MIP. We aimed to conduct a systematic review and metanalysis to evaluate the diagnostic performance of 4DCT and FCH PET/CT scan for quadrant wise localisation in PHPT patients and to do head-to-head comparison between these two modalities. DESIGN, PATIENTS AND MEASUREMENT : After searching through PubMed and EMBASE databases, 46 studies (using histology as a gold standard) of 4DCT and FCH PET/CT were included. RESULTS: Total number of patients included were 1651 and 952 for 4DCT scan (studies n = 26) and FCH PET/CT scan (studies n = 24) respectively. In per patient analysis, FCH PET/CT and 4DCT had pooled sensitivities of 92% (88-94) and 85% (73-92) respectively and in per lesion analysis, 90% (86-93) and 79% (71-84), respectively. In the subgroup with negative conventional imaging/persistent PHPT, FCH PET/CT had comparable sensitivity to 4DCT (84% [74-90] vs. 72% [46-88]). As per patient wise analysis, FCH PET/CT had better detection rates than 4DCT ([92.4 vs. 76.85], odds ratio -3.89 [1.6-9.36] p = .0024) in the subpopulation where both FCH PET/CT and 4DCT were reported. CONCLUSION: Both 4DCT and FCH PET/CT scan performed well in newly diagnosed patients, patients with persistent disease and in those with inconclusive conventional imaging results. FCH PET/CT scan had a higher pooled sensitivity than 4DCT in detecting patients with PHPT in head to head comparison.

Normocalcemic primary hyperparathyroidism

Normocalcemic primary hyperparathyroidism (PHPT) is a newer phenotype of PHPT defined by elevated PTH concentrations in the setting of normal serum calcium levels. It is increasingly being diagnosed in the setting of evaluation for nephrolithiasis or metabolic bone diseases. It is important to demonstrate that PTH values remain consistently elevated and to measure ionized calcium levels to make the diagnosis. A diagnosis of normocalcemic disease is one of exclusion of secondary forms of hyperparathyroidism, including vitamin D deficiency, renal failure, medications, malabsorption, and hypercalciuria. Lack of rigorous diagnostic criteria and selection bias of the studied populations may explain the different rates of bone and renal complications. The natural history still remains unknown. Caution should be used in recommending surgery, unless clearly indicated. Here we will review the diagnostic features, epidemiology, clinical presentation, natural history, medical and surgical management of normocalcemic PHPT.

The effects of season (spring versus autumn) on diagnosis of normocalcemic primary hyperparathyroidism

BACKGROUND

Raised parathormone (PTH) and normal calcium concentrations can be observed both in normocalcemic primary hyperparathyroidism (nPHPT) and in secondary hyperparathyroidism, e.g. due to vitamin D deficiency. We assessed the impact of season on the validity of diagnosis of nPHPT in terms of screening investigations to be performed in the primary care settings.

MATERIAL AND METHODS

On two occasions (March/April & September/October) we measured vitamin D (25OHD), PTH and total calcium in 125 healthy subjects, age range 6-50, not taking any vitamin D supplements.

RESULTS

In autumn there was an increase in 25OHD concentrations (from 18.1 ± 7.37ng/ml to 24.58 ± 7.72ng/ml, p<0.0001), a decline in PTH from 44.40 ± 17.76pg/ml to 36.63 ± 14.84pg/ml, p<0.001), without change in calcium levels. Only 45 subjects (36%) were vitamin D sufficient (25OHD>20/ml) in spring versus 83 (66.4%) in autumn, p<0.001. Elevated PTH concentrations were noted in 10 subjects in spring (8%) and in six subjects (4.8%) (p<0.05) in autumn. In spring, however, eight out of ten of these subjects (80%) had 25OHD<20 ng/ml, versus one in six (16.7%) in autumn (p<0.01). Normalization of PTH was observed in seven out ten subjects (70%), and all of them had 25-OHD<20 ng/ml in spring.

CONCLUSIONS

In spring elevated PTH concentrations in the setting of normocalcemia are more likely to be caused by 25OHD deficiency rather by nPHPT. In contrast, in autumn, increased PTH concentrations are more likely to reflect nPHPT. We postulate that screening for nPHPT should be done in 25OHD replete subjects, i.e. in autumn rather than in spring.

Evaluation and Management of Elevated Parathyroid Hormone Levels in Normocalcemic Patients

Primary hyperparathyroidism is a common endocrine disorder. It used to present as a highly symptomatic disease before the advent of the multichannel autoanalyzer, now usually presenting as mild asymptomatic hypercalcemia. A newer presentation has been increasingly identified in the past two decades, normocalcemic primary hyperparathyroidism, presenting with elevated parathyroid hormone concentrations and consistently normal serum calcium. These patients are usually symptomatic, with parathyroid hormone levels measured in the evaluation for kidney stones or osteoporosis. It is important to exclude causes of secondary hyperparathyroidism. This review will focus on the evaluation and management of elevated parathyroid hormone levels in normocalcemic patients.

Normocalcemic and Normohormonal Primary Hyperparathyroidism: Laboratory Values and End-Organ Effects

OBJECTIVE

Variants of primary hyperparathyroidism (pHPT), described as normocalcemic (NC) and normohormonal (NH), can confuse the diagnosis of classic pHPT.

DATA SOURCES

A MEDLINE search was performed for variants of pHPT using the PubMed database (last queried October 2019).

REVIEW METHODS

The search was restricted to articles published after 1960 that were specific to humans. Studies were included in our analysis if laboratory values and incidence of end-organ involvement were reported for NCpHPT and NHpHPT variants. The search returned 189 articles; 27 additional studies were identified and included for a total of 216. Non-English-language studies were excluded. Abstracts were screened, full-text articles were then assessed, and 82 articles were excluded. Data were pooled using a random-effects model in studies that compared NC or NH pHPT to classic pHPT. Comparative laboratory values are presented.

CONCLUSION

This analysis compares NCpHPT and NHpHPT to classic pHPT. Nephrolithiasis was 21.7% (NCpHPT), 15.9% (classic pHPT), and 25.4% (NHpHPT). Decreased bone mineral density was 49.7% (NCpHPT), 39.7% (classic pHPT), and 40.3% (NHpHPT). Fractures in the NCpHPT group were not significantly different from the classic pHPT. Hypertension in the NCpHPT group was significantly less than classic pHPT (odds ratio, 0.59; 95% CI, 0.40-0.88).

IMPLICATIONS FOR CLINICAL PRACTICE

This information may serve to inform clinicians of the laboratory subtleties of these variants that are being seen with greater frequency in contemporary practice.

Impaired physical function and evaluation of quality of life in normocalcemic and hypercalcemic primary hyperparathyroidism

INTRODUCTION

Severe primary hyperparathyroidism may be associated with muscle weakness and fatigue, but little is known about this effect in milder forms of the disease. This study aimed to evaluate physical function and quality of life in patients with normocalcemic (NPHPT) and hypercalcemic (HPHPT) primary hyperparathyroidism.

METHODS

This was a case-control study on 40 postmenopausal women. Thirteen patients with NPHPT, 7 patients with HPHPT, and their controls were studied. Mean serum PTH in the control group was 49.10 ± 12.38 pg/mL. All of the participants answered the Medical Outcomes Short-Form Health Survey (SF36) and were submitted to 2 strength tests (Hand Grip strength and Chair stand test) and 2 performance tests for physical function (Short physical performance battery and Gait speed). Body composition analysis was performed by dual-energy X-ray absorptiometry (DXA) and multifrequency bioimpedance (BIA).

RESULTS

Patients with NPHPT had lower grip strength (p = 0.005), a higher mean time of the chair stand test (p = 0.012), a lower mean gait speed (p < 0.001) and a lower score for the Short Physical Performance Battery (SPPB) (p = 0.010) than the control group. Patients with HPHPT had lower handgrip strength (p = 0.027), a higher mean time of the chair stand test (p = 0.017), and a lower score for the SPPB (p = 0.049) than the control group. Patients with NPHPT showed a higher gait speed when compared to HPHPT (p = 0.048). There was no difference between BIA and DXA body composition indices between the PHPT groups and their controls. The evaluation of the SF-36 showed significantly less quality of life in the general health domain among the NPHPT group and in the mental health domain among the HPHPT than in the controls.

CONCLUSION

Patients with NPHPT and HPHPT have decreased physical performance and strength.

Normocalcemic primary hyperparathyroidism: an update

Normocalcemic primary hyperparathyroidism (NPHPT) is diagnosed in the setting of elevated PTH concentrations with consistently normal albumin-adjusted and ionized serum calcium levels, in absence of secondary causes for elevated PTH concentrations. In order to confirm persistence of the hyperparathyroid state, PTH levels should be elevated on at least two occasions over a 3 to 6 months period. The prevalence of NPHPT depends on the population studied. Data from different studies are often not comparable; indeed, different criteria have been used to exclude secondary hyperparathyroidism. Notwithstanding such limits, the prevalence of NPHPT in studies including ionized calcium dosage was between 0.5% and 0.7%. Available data suggest that patients with NPHPT are likely to have more skeletal, kidney and metabolic complications compared to healthy subjects, but almost all studies suffer from possible misclassification of patients due to lack of ionized calcium dosage. The management of NPHPT is controversial in part due to lack of solid data about the natural history. However, surgical treatment is currently performed more frequently than in the past, although studies do not show, so far, a clear benefit from intervention.

Normocalcemic Hyperparathyroidism: A Heterogeneous Disorder Often Misdiagnosed?

Normocalcemic primary hyperparathyroidism (NHPT) was first described over 10 years ago, but uncertainties still remain about its definition, prevalence, and rates of complications. As a result, consensus management guidelines for this condition have not yet been published. Several hypotheses have been proposed for the pathophysiology of NHPT, but it may be a heterogeneous disorder with multiple causes, rather than a single etiology that explains this biochemical phenotype. A common clinical concern is whether NHPT should be treated surgically when complications are already present at first recognition of the disorder, rather than following patients clinically over time. The literature on NHPT is based mostly on larger studies of population‐based cohorts and smaller studies from referral centers. Lack of rigorous diagnostic criteria and selection bias inherent in populations seen at tertiary referral centers may explain the heterogeneity of reported rates of bone and renal complications in relation to consistently mild laboratory alterations. Unresolved questions remain about the significance of NHPT when it is diagnosed biochemically without evident bone or kidney complications. Moreover, its natural history remains to be elucidated because a proportion of what is classified as NHPT may revert to normal spontaneously, thus revealing previously unrecognized secondary hyperparathyroidism. These issues indicate that caution should be used in recommending surgery for NHPT. This review will focus on recent issues regarding the pathophysiology, evaluation, and management of NHPT. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Clinical, Biochemical, and Radiological Profile of Normocalcemic Primary Hyperparathyroidism

CONTEXT

The clinical and radiological aspects of normocalcemic hyperparathyroidism (NHPT) are confounded by the differing methods used to rule out secondary hyperparathyroidism and by the small sample size.

OBJECTIVE

To assess the clinical, biochemical, and radiological profile of NHPT compared with primary hyperparathyroidism (PHPT) and control subjects.

DESIGN

Multicentric cross-sectional study.

SETTING

Outpatient clinic.

PATIENTS

47 NHPT, 41 PHPT, and 39 age- and sex-matched control subjects.

MAIN OUTCOME MEASURES

Calcium metabolism and bone turnover markers (BTMs). Lumbar spine, total hip, femoral neck, one-third distal radius bone mineral density (BMD). Morphometric vertebral fracture (VF) assessed by dual-energy X-ray absorptiometry.

RESULTS

NHPT patients had significantly higher parathyroid hormone, 25(OH)-vitamin D levels and lower calcium × phosphorus product than controls (P < .001). Compared with PHPT, the NHPT group had significantly higher 25(OH) vitamin D levels (P = .016). NHPT had BTM levels similar to controls and PHPT. NHPT, PHPT, and controls have similar lumbar spine and femoral neck BMD. NHPT and controls had a similar radial BMD, while patients with PHPT had a lower radial BMD than both patients with NHPT (P = .031) and controls (P < .05). Using the control group as the reference, after adjustment for interacting factors, there was no increase in risk of moderate-severe VF in NHPT (odds ratio [OR] 1.04, 95% confidence interval [CI] 0.25-4.55), while PHPT had an increased risk (OR 3.81,95% CI 1.15-15.12). Seventy-nine percent of NHPT and 59% of PHPT patients fulfilled the criteria for asymptomatic hyperparathyroidism.

CONCLUSIONS

The biochemical phenotype of NHPT is intermediate between PHPT and controls. In contrast, the bone phenotype resembles controls with normal bone turnover, no significant BMD impairment, and no increased risk of VF.

Normocalcemic Hyperparathyroidism: Study of its Prevalence and Natural History

CONTEXT

Normocalcemic hyperparathyroidism (NPHPT) is characterized by persistently normal calcium levels and elevated parathyroid hormone (PTH) values, after excluding other causes of secondary hyperparathyroidism. The prevalence of the disease varies greatly and the data on the natural history of this disease are sparse and inconclusive.

OBJECTIVES

The objectives of this study are to describe the prevalence of NPHPT and its natural history in a referral population and to compare the variability of serum calcium with a group of patients with primary hyperparathyroidism (PHPT).

DESIGN

A retrospective study was conducted over 5 years.

SETTING

The setting for this study was a metabolic bone referral center.

PATIENTS

A total of 6280 patients were referred for a bone mineral density measurement (BMD).

MAIN OUTCOME MEASURES

The prevalence and natural history of NPHPT and variability of calcium were the main outcome measures.

RESULTS

We identified NPHPT patients using data from the day of the BMD measurement. We excluded patients with low estimated glomerular filtration rate (eGFR) or vitamin D, or with no measurements available. Based on the evaluation of their medical files, we identified 11 patients with NPHPT (prevalence 0.18%). Only 4 patients had consistent normocalcemia throughout their follow-up, with only 2 also having consistently high PTH. None had consistently normal eGFR or vitamin D.Intermittent hypercalcemia was present in 7 of the 11 NPHPT patients. The mean adjusted calcium was found to be significantly lower in the NPHPT group compared with the PHPT group but higher than the control group. PTH was similar for NPHPT and PHPT. These 2 groups had similar variability in serum calcium.

CONCLUSIONS

NPHPT patients often have episodes of hypercalcemia. We believe that NPHPT is a mild form of PHPT.

Vocal cord paralysis due to ectopic parathyroid adenoma and function recovery: a case report and review of the literature

Ectopic parathyroid adenomas (PAs) can occur in numerous locations and are thought to be the cause of a significant portion of failed primary surgery for hyperparathyroidism. PA is a rare cause of hoarseness, which may be harbingers of a malignant process. Here, we describe an unusual case of an ectopic PA in the carotid sheath presenting as unilateral vocal cord paralysis (VCP). A 49-year-old lady presented with a 1-week history of hoarseness, irritating cough and shortness of breath. Fibreoptic laryngoscopy revealed left VCP. Ultrasound and computed tomography of the neck demonstrated a mass in the carotid sheath. Laboratory investigations revealed hypercalcemia (3.10 mmol/L), hypophosphatemia (0.81 mmol/L) and elevated intact parathyroid hormone (iPTH) level (381.6 pg/mL), despite of a negative ^99mTc-sestamibi scan. After more rigorous tests, the ectopic tumor adjacent to the left vagus nerve was successfully resected, with subsequent histopathological confirmation of PA. The patient eventually got a normal iPTH level and serum calcium postoperatively, and regular voice function was also regained 4 months after surgery. This case emphasizes the importance of broad differential diagnosis and thorough workup. Although most patients with PA present with hypercalcemia, this disease entity also need to be considered in the differentials of neck masses and VCP.

Hyperparathyroidism in men - morbidity and mortality during 21 years' follow-up

Hyperparathyroidism (HPT), including normocalcaemic, vitamin D sufficient (Serum (S)-25(OH)D ≥ 50 nmol/L) hyperparathyroidism (nHPT), has increasingly been diagnosed in the last few decades due to the more common use of the serum parathyroid hormone (S-PTH) assay. We investigated if men with HPT had higher morbidity and mortality than men without HPT during 21 years' follow-up.A random population sample of 750 men, all 50 years of age, was examined in 1993. Endpoints were retrieved 21 years later at 71 years of age.Albumin-corrected serum (S) calcium, S-25-hydroxyvitamin D and S-PTH were assessed along with data on cardiovascular risk factors and medication. Outcome data on fractures, stroke, myocardial infarction, cancer and death were retrieved in 2014; 21 years after primary assessment. The prevalence of HPT at 50 years of age was 9.3%; nHPT 2.8%, primary HPT 0.4%, secondary HPT 0.4%, and HPT with vitamin D insufficiency 6%. Fracture rate, myocardial infarction, stroke, cancer and death occurred similarly in men with or without HPT, as well as in men with nHPT as compared with men without calcium/PTH aberrations during 21 years' follow-up. S-PTH was evenly distributed in the univariable analyses for each outcome. Cox regression analyses showed no increase in serious morbidity or in mortality in men with HPT, irrespective of cause, compared with men with normal S-PTH over a 21-year period. None had HPT at a S-25(OH)D level of 100 nmol/L.

Primary hyperparathyroidism: should surgery be performed on all patients? Current evidence and residual uncertainties

Primary hyperparathyroidism (pHPT) is the third most common endocrine disease and is characterized by hypercalcaemia and elevated or inappropriately 'normal' levels of the parathyroid hormone (PTH). The main target organs of PTH are the skeletal system and the kidneys. Before the 1970s, pHPT was a rarely detected disease associated with notable morbidity and premature mortality. Introduction of biochemical screening, allowing for a wide range of indications, has contributed to the detection of the full spectrum of the disease. A new entity with an isolated elevation of PTH, normocalcaemic HP, has emerged and is currently being explored. The highest incidence of pHPT, 3-5%, is observed amongst women, and the prevalence increases with age. The female-to-male ratio is 3-4 : 1 except in younger patients where distribution is equal and known hereditary causes account for approximately 10% of the cases. In the last few decades, it has become evident that fewer patients than previously believed are truly asymptomatic. The cause of pHPT is often a benign tumour, a parathyroid adenoma, and the only definite treatment is parathyroidectomy (PTX). No medical treatment, single or combined, can achieve a curing of pHPT. Recent data indicate that PTX, despite being proven to be cost-effective compared to conservative treatment, is underutilized, especially in elderly pHPT patients. The decision of PTX should always be based on a safe diagnosis, and the potential benefits of curative treatment should not be outweighed by the risks of surgery or anaesthesia.

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.

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.

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.

Total parathyroidectomy with forearm auto-transplantation improves the quality of life and reduces the recurrence of secondary hyperparathyroidism in chronic kidney disease patients

BACKGROUND

Our study aims to explore the effect of total parathyroidectomy (PTX) with forearm autotransplantation (FAT) on the quality of life and recurrence of secondary hyperparathyroidism (SHPT) in chronic kidney disease patients.

METHODS

A total of 104 chronic kidney disease patients with SHPT were enrolled and divided into the PTX (n = 62) and PTX + FAT (n = 42) groups. The operation efficacy was evaluated by analyzing preoperative and postoperative values, including levels of intact parathyroid hormone (iPTH), serum phosphorus, serum calcium, alkaline phosphatase (ALP), calcium-phosphorus product, signs and symptoms, and MOS 36-item short-form health survey (SF-36) scores. Moreover, complications and recurrences were followed up for 12 months after the operation. Binary logistic regression was to present the risk factors for the recurrence of chronic kidney disease patients with SHPT.

RESULTS

Compared with the preoperative values, the PTX and PTX + FAT groups showed decrease postoperative levels of iPTH, serum phosphorus, serum calcium, calcium-phosphorus product, bone pain, and skin pruritus at all time periods. The PTX and PTX + FAT groups demonstrated decreased ALP, fracture or deformity, and coronary artery calcification at 1 month, decreased short stature at 3 months after the operation but increased SF-36 score after operation. Compared with the PTX group, the level of iPTH decreased and the levels of serum calcium, calcium-phosphorus product increased at 3, 6, and 12 months after the operation in the PTX + FAT group. The levels of ALP, fracture or deformity, short stature, and SF-36 decreased separately at 1 week and 6 and 12 months after the operation, along with the decrease of coronary artery calcification and the recurrence rate, respectively, at 6 and 12 months after the operation in the PTX + FAT group when compared with those in the PTX group. Logistic regression analysis evidenced that the preoperative iPTH level, SF-36 score, and operation type were the risk factors for the recurrence of chronic kidney disease with SHPT.

CONCLUSION

Total PTX combined with FAT is more effective in improving the quality of life and reducing the recurrence of chronic kidney disease with SHPT than PTX alone.

Evaluation of coronary calcium score in patients with normocalcemic primary hyperparathyroidism

RATIONALE

Given that the diagnosis of primary hyperparathyroidism (PHPT) is given at an increasingly less-symptomatic phase, and the literature data on the cardiovascular risk of patients with normocalcemic primary hyperparathyroidism (NPHPT) are controversial, the coronary calcium score (CCS), which is correlated with coronary artery disease, may be useful for clarifying the association between cardiovascular risk and NPHPT.

OBJECTIVE

This research aims to describe the CCS and the clinical and laboratory variables of patients with NPHPT compared with a control group and to verify the presence of an association between NPHPT and CCS.

STUDY POPULATION AND METHODS

A questionnaire on anthropometric data (weight, height, waist circumference, and blood pressure) was used, laboratory examinations (estimations of glucose, glycated hemoglobin [HbA1c], total cholesterol [TC] and its fractions, triglycerides, creatinine, calcium, parathyroid hormone, and 25-OH vitamin D) were conducted, and computerized tomography was carried out to measure the CCS in 13 patients diagnosed with NPHPT and 16 controls.

RESULTS

There was no association between NPHPT and altered CCS (odds ratio [OR]: 0.27; 95% confidence interval [CI]: 0.05-1.26; p=0.095). Differences between the case and control groups were found in terms of body mass index (BMI) (26.97 kg/m² vs 31.53 kg/m², respectively; p=0.044), HbA1c (5.59% vs 6.62%; p=0.000), and TC (188.07 mg/dL vs 220.64 mg/dL; p=0.088). After adjustment for potential confounders, no statistical significance was observed for the association between changes in CCS and presence of NPHPT (adjusted OR: 1.64; 95% CI: 0.1-26.43; p=0.726).

CONCLUSION

No association was found between the CCS and the presence of NPHPT.

Development of an algorithm to predict serum vitamin D levels using a simple questionnaire based on sunlight exposure

Sun exposure is the main determinant of vitamin D production. The aim of this study was to develop an algorithm to assess individual vitamin D status, independently of serum 25(OHD) measurement, using a simple questionnaire, mostly relying upon sunlight exposure, which might help select subjects requiring serum 25(OHD) measurement. Six hundred and twenty adult subjects living in a mountain village in Southern Italy, located at 954 m above the sea level and at a latitude of 40°50'11″76N, were asked to fill the questionnaire in two different periods of the year: August 2010 and March 2011. Seven predictors were considered: month of investigation, age, sex, BMI, average daily sunlight exposure, beach holidays in the past 12 months, and frequency of going outdoors. The statistical model assumes four classes of serum 25(OHD) concentrations: ≤10, 10-19.9, 20-29.9, and ≥30 ng/ml. The algorithm was developed using a two-step procedure. In Step 1, the linear regression equation was defined in 385 randomly selected subjects. In Step 2, the predictive ability of the regression model was tested in the remaining 235 subjects. Seasonality, daily sunlight exposure and beach holidays in the past 12 months accounted for 27.9, 13.5, and 6.4 % of the explained variance in predicting vitamin D status, respectively. The algorithm performed extremely well: 212 of 235 (90.2 %) subjects were assigned to the correct vitamin D status. In conclusion, our pilot study demonstrates that an algorithm to estimate the vitamin D status can be developed using a simple questionnaire based on sunlight exposure.

Elevated PTH with normal serum calcium level: a structured approach

Normocalcaemic hyperparathyroidism is a common biochemical finding, usually identified during an assessment of bone or renal health. Hypercalcaemia must be considered by calculation of adjusted calcium, and a careful history taken to assess dietary calcium intake and for the possibility of a malabsorption syndrome. 25-hydroxyvitamin D (25OHD) should be measured and replaced if indicated. The management plan for the patient is influenced by the context in which calcium and PTH were measured. In this brief review we describe the assessment of a patient with normocalcaemic hyperparathyroidism.

Primary Hyperparathyroidism

Over the past several generations, primary hyperparathyroidism (PHTP) has undergone a change in its clinical presentation in many countries from a symptomatic disease to an asymptomatic one. The reasons for this change in clinical presentation are related to the widespread use of biochemical screening tests, to the measurement of PTH more routinely in the evaluation of metabolic bone disease and to the status of vitamin D sufficiency in the population. Along with recognition of a broader clinical spectrum of disease, including a more recently recognized normocalcemic variant, has come an appreciation that the evaluation of classic target organs that can be affected in PHPT, such as the skeleton and the kidneys, require more advanced imaging technology for complete evaluation. It is clear that even in asymptomatic patients, evidence for microstructural disease in the skeleton and calcifications in the kidneys can be demonstrated often. Potential non-classical manifestations of PHPT related to neurocognition and the cardiovascular system continue to be of interest. As a result of these advances, revised guidelines for the management of asymptomatic PHPT have been recently published to help the clinician determine whether surgery is appropriate or whether a more conservative approach is acceptable.