Sex Difference in the Clinical Presentation of Primary Hyperparathyroidism: Influence of Menopausal Status

Primary hyperparathyroidism: from guidelines to outpatient clinic

Primary hyperparathyroidism (PHPT) is a common endocrine disease characterized by hypercalcemia due to inappropriately high parathyroid hormone secretion. While in the typical, symptomatic form of the disease diagnosis is set easily and standard management is surgical removal of the hyperfunctioning parathyroid (HP), this may not be the case in more subtle forms of PHPT, such as the asymptomatic and the normocalcemic PHPT. Localization of the HP could also be challenging, especially in small-sized adenomas, ectopic lesions or multiglandular disease. An experienced surgical team is essential to achieve curative parathyroidectomy. In this article, we used illustrative clinical vignettes to dissect the approach to the patient with PHPT, from the diagnosis establishment to the suggested investigation to identify classical and non-classical PHPT features and the methodology to locate the abnormal tissue. Accordingly, we elaborated on appropriate management, both surgical and conservative.

Calcium/phosphate ratio: an additional tool for the clinical management of asymptomatic primary hyperparathyroidism?

PURPOSE

Serum calcium/phosphate ratio (Ca/P) has been recently proposed as an additional tool to identify primary hyperparathyroidism (PHPT), especially in patients with subclinical presentation, with a proposed cut-off of 3.3 when both values are expressed in mg/dL. No data are available on the relationship between Ca/P and the clinical presentation of PHPT. We thus evaluated this relationship in a large, single-center, unselected series.

METHODS

515 consecutive PHPT patients (mean age 65 ± 13.15 years, 77.1% females) were retrospectively evaluated at diagnosis.

RESULTS

Mean Ca/P was 4.54 ± 1.5 (range 2.36-13.9), being higher than 3.3 in 88.5% of patients. Ca/P was significantly higher in (1) males, (2) symptomatic PHPT, (3) patients with 25-hydroxy vitamin D levels lower than 20 μg/L, (4) patients with osteitis fibrosa cystica, (5) patients with T score < - 2.5 at the radial site. In a multivariate regression analysis, Ca/P resulted significantly associated with PTH levels. After the exclusion of 57 patients with asymptomatic PHPT (aPHPT) patients and serum Ca higher than 1 mg/dL above the upper limit of normal range, no differences were found in Ca/P between aPHPT meeting or not surgical criteria.

CONCLUSIONS

In PHPT Ca/P ratio is associated with increased biochemical and clinical severity of disease and represents a direct indicator of clinical bone damage. However, it does not seem an additional tool to identify aPHPT patients reaching surgical indication.

Systematic review of the risk of urolithiasis following parathyroidectomy in patients with primary hyperparathyroidism

OBJECTIVE

Parathyroidectomy (PTX) is the conclusive therapy for primary hyperparathyroidism (PHPT), but its effect on the risk of urolithiasis is inconclusive. We comprehensively reviewed the currently available research to investigate the impact of PTX on the likelihood of urolithiasis among individuals suffering PHPT.

METHODS

Internet-based articles in English language released on Cochrane, PubMed, Scopus, Web of knowledge, and Embase up to September, 2023 were comprehensively reviewed. Each publication in contrast to the incidence, occurrence, or recurrence of urolithiasis after PTX versus medical treatment in PHPT patients was included. The outcome with pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) was examined employing DerSimonian and Laird's model of random effects. To determine the range of the real effect size of a future study in 95% of all populations, a prediction interval (PI) was also established.

RESULTS

Finally, ten studies involving 74,190 patients were included. Results from randomized-controlled trials (RCTs) and observational studies (OSs) both revealed that PTX did not substantially lessen the vulnerability of urolithiasis among individuals with PHPT (RCTs: pooled relative risk [RR] 0.42, 95%CI 0.13-1.41, p = 0.163; OSs: pooled RR 1.37, 95%CI 0.96 to 1.97, p = 0.084). The PI (RCT: 0.03 to 5.96; OSs: 0.44-4.20) containing 1.0 suggested the possibility of consistent results in future studies. Subgroup and sensitivity analyses supported the above findings, and no evidence showed publication bias.

CONCLUSION

Our analysis from the available RCTs or OSs did not give adequate or exact proof that the average effect of PTX lowers the incidence of urolithiasis among PHPT persons based on the random-effects model. Future research shall take into account the common effect of PTX as well as the prerequisites of preventive stone procedures, which will further help us assess the effectiveness of PTX in reducing kidney calculus comorbidity and develop techniques to avoid stone sequelae in these individuals.

[Hyperparathyroidism of different genesis in young patients with Turner syndrome: case series and brief review]

Hyperparathyroidism is a syndrome characterized by an excessive secretion of parathyroid hormone. Etiologically, hyperparathyroidism is subdivided into primary hyperparathyroidism, which develops as a result of parathyroid adenoma, carcinoma or hyperplasia, and secondary hyperparathyroidism, which happens as a compensatory response to a hypocalcemia caused by condition outside the parathyroid glands. Turner syndrome may also be accompanied by mineral metabolism disorders of various etiology. An association of hyperparathyroidism and Turner syndrome is interesting because of multifactorial impact on bone mineral density, but only few cases of such coexistence have been previously described in the literature. This article describes two patients with Turner syndrome and hyperparathyroidism of different etiology. Hyperparathyroidism, normocalcemia, vitamin D deficiency, osteoporosis, parathyroid tumors were found in both cases. In one case a number of assays was performed to confirm the patient's normocalcemic primary hyperparathyroidism, and surgery was performed to achieve remission. In the second case, treatment of vitamin D deficiency resulted in normalization of serum concentration of parathormone, after which the patient was prescribed antiresorptive therapy. The pathogenetic association between Turner syndrome and hyperparathyroidism requires further investigation. Comprehensive approach to the diagnosis and treatment of mineral metabolism disorders are essential for patients with coexistence of these two diseases.

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.

Sex differences in patients with primary hyperparathyroidism

BACKGROUND

Differences in presenting symptoms of primary hyperparathyroidism and outcomes of parathyroidectomy between sexes have been described, but whether these can be assessed by perioperative use of a validated tool, such as the Pasieka Parathyroidectomy Assessment Score, is unknown.

METHOD

All patients with primary hyperparathyroidism were asked to complete symptom assessment at the preoperative and postoperative visits. The assessment included a query for 13 Pasieka Parathyroidectomy Assessment Score parameters evaluated using a visual analog scale as described by Pasieka (summative score 0-1,300), and general quality of life and wellness. A review of a prospectively maintained database of primary hyperparathyroidism patients (January 2016-December 2019) was performed, and those who had a 6-month cure after initial parathyroidectomy were included.

RESULTS

The study cohort was mostly women (77%, 541/701). The median preoperative Pasieka Parathyroidectomy Assessment Score was higher in women (155, 0-1,190) than in men (80.5, 0-855, P < .001), although there were similar rates of asymptomatic primary hyperparathyroidism (Pasieka Parathyroidectomy Assessment Score = 0, 12.5% vs 7%, P = .042). After curative parathyroidectomy, women reported a substantial reduction in symptomatology, with Pasieka Parathyroidectomy Assessment Score declining by 35% at initial postoperative visit (median, 155 vs 100, P < .001), further decreasing to 48% by 6 months (155 vs 80, P < .001). The Pasieka Parathyroidectomy Assessment Score in men did change but to a much smaller degree at both the initial postoperative visit (80.5 vs 70; P = .036) and at 6 months (80.5 vs 57.5; P = .048).

CONCLUSION

When assessed with the Pasieka Parathyroidectomy Assessment Score, improvement in symptoms was clearly demonstrated for women after curative parathyroidectomy. Whether symptom improvement also occurs in men is less apparent but may be due to disparities in the development and validation of outcomes tools in general.

The Impact of Moderate Hypophosphatemia on the Clinical Management of Primary Hyperparathyroidism

Background and objective The impact of moderate hypophosphatemia (hypoP) on primary hyperparathyroidism (PHPT) and its use as an independent surgical criterion has not been adequately evaluated in the literature. In light of this, we conducted this study to address the scarcity of data on this topic. Methods We conducted a retrospective evaluation of data related to 164 (133 females and 31 males) patients with PHPT who met the criteria for inclusion in the study. HypoP, which is indicated by phosphorus (P) levels lower than 2.5 mg/dL, was found in 78 (47.5%) patients, and moderate hypoP (1-1.99 mg/dL) was found in 25 patients (15.2%). Results PHPT severity was worse in hypoP patients than non-hypoP patients, as evidenced by higher levels of mean serum calcium (12.9 ±1.0 mg/dL vs. 11.1 ±0.3 mg/dL respectively, p<0.001), parathormone (PTH) [median (interquartile range, IQR): 455.3 (455.3) ng/L vs. 124.0 (84.0) ng/L respectively, p<0.001] and mean 24-hour urinary calcium (414.6 ±168.5 mg/day vs. 291.5 ±161.4 mg/day respectively, p=0.026) as well as lower levels of mean BMI (25.6 ±3.9 kg/m2 vs. 29.0 ±4.0 kg/m2 respectively, p=0.18) and mean 25-hydroxy vitamin D3 (13.8 ±7.3 µg/L vs. 18.2 ±7.8 µg/L respectively, p=0.001). Among the whole study population as well as among patients with Ca levels <1.0 mg/dL according to the upper limit of normal, P level was determined to be an independent factor affecting the indication for surgical treatment [β: -1.96,p=0.038, odds ratio (OR): 0.14, 95% confidence interval (CI): 0.02-0.89 and β: -2.3, p=0.034, OR: 0.10, 95% CI: 0.12-0.84 respectively]. Conclusion We found a strong correlation between moderate hypoP and the severity of the biochemical manifestations of PHPT. In asymptomatic PHPT patients, moderate hypoP was predictive of surgical indication, independent of age and level of hypercalcemia.

Differences in the Presentation and Outcome between Premenopausal and Postmenopausal Primary Hyperparathyroidism Indian Women: A Single-Center Experience

Introduction

Primary hyperparathyroidism (PHPT) is an endocrine disorder wherein enlargement of one or more of the parathyroid glands causes autonomous overproduction of the parathyroid hormone (PTH), which leads to high serum calcium levels.

Objective

The objective of this study was to compare the clinical, laboratory, and operative variables between premenopausal (pre-M) and postmenopausal (post-M) women with PHPT.

Materials and Methods

A retrospective analysis of the data of female patients who underwent surgery for PHPT at a single center, from January 2011 to December 2020, was done. Patients with familial PHPT and secondary hyperparathyroidism were not included.

Results

Of the 130 women with PHPT, 44.6% were pre-M and 55.4% were post-M. A significantly higher number of pre-M females were symptomatic compared to post-M females (pre-M vs. post-M, 84.5% vs. 68.1%, P = 0.031). Renal calculi were more common in pre-M women (34.5% vs. 18.1%, P = 0.032), while the rest of the clinical features were comparable between the two groups. The proportion of women with osteoporosis (6.7% vs. 19.4%, P = 0.071), hypertension (13.8% vs. 34.7%, P = 0.012), and diabetes mellitus (3.5% vs. 16.7%, P = 0.033) was lesser in the pre-M group. Elevated serum alkaline phosphatase levels were significantly more prevalent in the pre-M group (37.9% vs. 20.8%, P = 0.032). The mean serum calcium (12.35 ± 1.28 vs. 11.96 ± 1.22 mg/dL, P = 0.079), median serum PTH (334 vs. 239 pg/mL, P = 0.051), and median weight of the operated adenomas (1.75 vs. 1.45 g, P = 0.075) were also higher in pre-M females. The proportion of ectopic adenomas and multiple adenomas, presurgery adenoma localization rates, and disease cure rates did not differ according to the menopausal status. The occurrence of postoperative hungry bone syndrome was higher in the pre-M women (15.5% vs. 1.4%, P = 0.008).

Conclusion

The majority of women with PHPT are post-M, but symptomatic presentation is more common in pre-M females. The severity of the disease appears to be more in pre-M women; however, imaging and operative variables generally did not significantly differ between the two groups.

Positive Effect of Parathyroidectomy Compared to Observation on BMD in a Randomized Controlled Trial of Mild Primary Hyperparathyroidism

Mild or asymptomatic disease is now the dominating presentation of primary hyperparathyroidism (PHPT). However, bone involvement with decreased bone mineral density (BMD) and an increased risk of fractures has been demonstrated. Indications for parathyroidectomy (PTX) in mild PHPT have been debated for years. There is a need of long-term randomized studies comparing PTX with observation without intervention (OBS). Here, we present bone health data from the Scandinavian Investigation of Primary Hyperparathyroidism (SIPH), a randomized controlled trial, comparing PTX to OBS. This study included 191 patients (96 OBS/95 PTX), and 129 patients (64 OBS/65 PTX) were followed for 10 years to the end of study (EOS). BMD was measured with dual-energy X-ray absorptiometry (DXA), peripheral fractures were noted, and spine radiographs were obtained for vertebral fracture assessment. There was a significant treatment effect of PTX on BMD compared with OBS for all analyzed compartments, most explicit for the lumbar spine (LS) and femoral neck (FN) (p < 0.001). The mean changes in T-score from baseline to 10 years were from 0.41 for radius 33% (Rad33) to 0.58 for LS greater in the PTX group than in the OBS group. There was a significant decrease in BMD for all compartments in the OBS group, most pronounced for FN, Rad33, and ultradistal radius (UDR) (p < 0.001). Even though there was a significant treatment effect of PTX compared with OBS, there was only a significant increase in BMD over time for LS (p < 0.001). We found no difference between groups in fracture frequency in the 10-year cohort, neither with modified intention-to-treat (mITT) analysis nor per protocol analysis. Because BMD is only a surrogate endpoint of bone health and PTX did not reduce fracture risk, observation could be considered a safe option for many patients with mild PHPT regarding bone health in a 10-year perspective. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Calcium requests in a primary care; An observational audit of biochemical requests and frequency of abnormal results

BACKGROUND/AIMS

This aim of this audit was to assess the extent of serum calcium testing and the frequency of hypercalcaemia in the primary care setting. We also assessed the appropriateness of subsequent investigations with repeat serum calcium and PTH testing if hypercalcaemia was identified.

METHODS

All laboratory requests for adjusted calcium and PTH samples sent from primary care in Glasgow were analysed over a 12 month period. This covered approximately 125 GP practices and a patient population of over 590,000.

RESULTS

There were 78,845 requests for adjusted calcium and 2053 PTH requests from 62,745 patients aged 16-105 years (median age 57, IQ range 30 years). Of these requests 1423 (2.3%) of patients had biochemical evidence of hypercalcaemia (adjusted calcium ≥ 2.61 mmol/L). Of the 1423 patients with hypercalcaemia, 368 patients (45.8%) had a single raised calcium level that was within the normal range on repeat testing. Of the 400 patients with persistent hypercalcaemia on 2 or more samples, 210 (52.5%) had a PTH measured. Eight patients had a PTH < 2.0 pmol/L, whilst 202 (96.1%) had a PTH ≥ 2.0 pmol/L (range 2.1-106.1 pmol/L).

CONCLUSIONS

Serum calcium was checked in 10.6% of the population per year within primary care. In the 2.4% with a raised calcium on initial testing, approximately half (45.8%) will normalise on repeat testing. Of those who remained persistently hypercalcaemic, only half (52.5%) had a PTH measured and the majority (96.1%) were in keeping with primary hyperparathyroidism being the most common cause of hypercalcaemia.

Single-cell RNA sequencing reveals the role of cell heterogeneity in the sex difference in primary hyperparathyroidism

OBJECTIVE

To explore the difference in parathyroid tissue-derived cells between male and female PHPT patients.

METHODS

Resected parathyroid tissues were collected from PHPT patients of both sexes. Single cells were isolated and sequenced for RNA expression profiles. The cell sequencing data were annotated by cell type, followed by population analysis, functional analysis, pathway analysis, cell communication analysis, differential gene expression analysis, and pseudotime trajectory analysis. The subcluster analyses were also performed in the parathyroid cells.

RESULTS

No substantial difference in the cell population, function, or communication is found between the two sexes. The interferon-a response, oxidative phosphorylation, and reactive oxygen species pathways are up-regulated in females than in male patients, mainly contributed by fibroblast cells, endothelial cells, parathyroid cells, and myeloid cells, which also have significantly more up-regulated pathways and cellular interactions than the other three cell types. The subcluster analysis of parathyroid cells identified five subpopulations: SPARCL1-OC and ISG15-OC are predominant in females, while more S100A13-PCC and PTHLH-OC are found in males. The cellular functions are also elevated in females compared with males. Cells from female patients show a higher expression level of parathyroid hormone (PTH) but a lower expression level of parathyroid hormone-like hormone (PTHLH). The cell pseudotime trajectory and pathway analyses show that the oxyphil cells may be more mature and functionally active than the chief cells in both sexes.

CONCLUSION

These findings suggest that the sex difference in PHPT may be caused by the differentially expressed genes and activated pathways in different cell types in the parathyroid tissue. The heterogeneity of parathyroid cell subpopulations, especially in oxyphil cells, may be associated with the sex differences in PHPT pathogenesis.

Classical and Nonclassical Manifestations of Primary Hyperparathyroidism

This narrative review summarizes data on classical and nonclassical manifestations of primary hyperparathyroidism (PHPT). It is based on a rigorous literature search, inclusive of a Medline search for systematic reviews from 1940 to December 2020, coupled with a targeted search for original publications, covering four databases, from January 2013-December 2020, and relevant articles from authors' libraries. We present the most recent information, identify knowledge gaps, and suggest a research agenda. The shift in the presentation of PHPT from a predominantly symptomatic to an asymptomatic disease, with its varied manifestations, has presented several challenges. Subclinical nephrolithiasis and vertebral fractures are common in patients with asymptomatic disease. The natural history of asymptomatic PHPT with no end organ damage at diagnosis is unclear. Some observational and cross-sectional studies continue to show associations between PHPT and cardiovascular and neuropsychological abnormalities, among the different disease phenotypes. Their causal relationship is uncertain. Limited new data are available on the natural history of skeletal, renal, cardiovascular, neuropsychological, and neuromuscular manifestations and quality of life. Normocalcemic PHPT (NPHPT) is often diagnosed without the fulfillment of rigorous criteria. Randomized clinical trials have not demonstrated a consistent long-term benefit of parathyroidectomy (PTX) versus observation on nonclassical manifestations. We propose further refining the definition of asymptomatic disease, into two phenotypes: one without and one with evidence of target organ involvement, upon the standard evaluation detailed in our recommendations. Each of these phenotypes can present with or without non-classical manifestations. We propose multiple albumin-adjusted serum calcium determinations (albumin-adjusted and ionized) and exclusion of all secondary causes of high parathyroid hormone (PTH) when establishing the diagnosis of NPHPT. Refining the definition of asymptomatic disease into the phenotypes proposed will afford insights into their natural history and response to interventions. This would also pave the way for the development of evidence-based guidance and recommendations. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Epidemiology, Pathophysiology, and Genetics of Primary Hyperparathyroidism

In this narrative review, we present data gathered over four decades (1980-2020) on the epidemiology, pathophysiology and genetics of primary hyperparathyroidism (PHPT). PHPT is typically a disease of postmenopausal women, but its prevalence and incidence vary globally and depend on a number of factors, the most important being the availability to measure serum calcium and parathyroid hormone levels for screening. In the Western world, the change in presentation to asymptomatic PHPT is likely to occur, over time also, in Eastern regions. The selection of the population to be screened will, of course, affect the epidemiological data (ie, general practice as opposed to tertiary center). Parathyroid hormone has a pivotal role in regulating calcium homeostasis; small changes in extracellular Ca++ concentrations are detected by parathyroid cells, which express calcium-sensing receptors (CaSRs). Clonally dysregulated overgrowth of one or more parathyroid glands together with reduced expression of CaSRs is the most important pathophysiologic basis of PHPT. The spectrum of skeletal disease reflects different degrees of dysregulated bone remodeling. Intestinal calcium hyperabsorption together with increased bone resorption lead to increased filtered load of calcium that, in addition to other metabolic factors, predispose to the appearance of calcium-containing kidney stones. A genetic basis of PHPT can be identified in about 10% of all cases. These may occur as a part of multiple endocrine neoplasia syndromes (MEN1-MEN4), or the hyperparathyroidism jaw-tumor syndrome, or it may be caused by nonsyndromic isolated endocrinopathy, such as familial isolated PHPT and neonatal severe hyperparathyroidism. DNA testing may have value in: confirming the clinical diagnosis in a proband; eg, by distinguishing PHPT from familial hypocalciuric hypercalcemia (FHH). Mutation-specific carrier testing can be performed on a proband's relatives and identify where the proband is a mutation carrier, ruling out phenocopies that may confound the diagnosis; and potentially prevention via prenatal/preimplantation diagnosis. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Primary hyperparathyroidism in Saudi Arabia revisited: a multi-centre observational study

PURPOSE

Primary hyperparathyroidism (PHPT) is a common cause of hypercalcemia and remains understudied within the Arabian population. The present study, the largest of its kind within the Gulf Cooperation Council (GCC) countries, aims to determine the demographics and clinical presentation of PHPT in Saudi Arabia.

METHODS

In this multi-center retrospective study involving three tertiary hospitals in different geographic locations of Saudi Arabia namely, Riyadh, Al Ahsa and Jeddah, a total of 205 out of 243 confirmed PHPT cases aged 16 to 93 years old were included (N = 96 from Riyadh; N = 59 from Al Ahsa and N = 50 from Jeddah). Demographics, clinical manifestations and surgical outcomes were recorded as well as laboratory and radiologic investigations including serum parathyroid hormone (PTH), 25(OH)D, adjusted calcium, estimated glomerular filtration rate (eGFR) and nuclear scan outcome.

RESULTS

PHPT cases appeared to increase over time when compared to other local studies published so far, with 12.8 cases per 100,000 hospital population. Females outnumber males (3:1) with 86% seen as out-patients. The average age was 59.8 ± 15.5 years. Abnormal PTH scan was seen in 171 patients (83.4%). Kidney stones was the most common renal manifestation (32 cases, 15.6%) and osteoporosis was the most common skeletal manifestation (67 cases, 32.7%). Al Ahsa had the highest prevalence of multiple comorbidities at 54% and the highest prevalence of obesity as a single comorbidity (17%) compared to other regions (p < 0.05). Jeddah recorded the highest prevalence of osteoporosis with bone and joint pains (30%) (p < 0.05).

CONCLUSION

Comparison of present data with previous local studies suggest an increasing trend in PHPT cases in Saudi Arabia. Regional variations in the clinical presentation of PHPT were observed and warrant further investigation.

Sex-Based Differences in Risk Factors and Complications of Chronic Kidney Disease

Globally, females are ∼30% more likely to have pre-dialysis chronic kidney disease (CKD) than males for reasons that are not fully understood. CKD is associated with numerous adverse health outcomes which makes understanding and working to eradicating sex based disparities in CKD prevalence essential. This review maps both what is known, and what is unknown, about the way sex and gender impacts (1) the epidemiology and risk factors for CKD including age, diabetes, hypertension, obesity, smoking, and cerebrovascular disease, and (2) the complications from CKD including kidney disease progression, cardiovascular disease, CKD mineral and bone disorders, anaemia, quality-of-life, cancer and mortality. This mapping can be used to guide future research.

Serum Phosphate: A Neglected Test in the Clinical Management of Primary Hyperparathyroidism

BACKGROUND

Although the inverse correlation between serum PTH and phosphate (P) levels in patients with primary hyperparathyroidism (PHPT) is well known, the relationship between P levels and the clinical picture of the disease has not been well investigated. This was thus the aim of this paper.

PATIENTS

A total of 472 consecutive patients with PHPT attending our center were retrospectively evaluated at diagnosis.

RESULTS

P levels lower than 2.5 mg/dL (HypoP) were found in 198/472 patients (41.9%). HypoP was mild (2-2.5 mg/dL), moderate (1-1.9 mg/dL), and severe (<1 mg/dL) in 168 (84.9%), 30 (15.1%), and 0 cases, respectively. P levels were lower in males than females. Patients with more severe bone density impairment at the radial (but not the vertebral or femoral) site had P levels significantly lower than other patients. PHPT severity was worse in HypoP patients, both clinically (higher prevalence of renal stones, but not of osteoporosis) and biochemically (higher serum calcium and PTH levels). All patients in the moderate HypoP group were either symptomatic or asymptomatic reaching surgical indication according to the latest guidelines.

CONCLUSIONS

We observed a relationship between P levels and biochemical and clinical features of PHPT severity. In asymptomatic PHPT patients, even moderate HypoP is predictive of surgical indication, regardless of age and hypercalcemia severity.

Value of [11C]-Methionine PET/CT in Preoperative Localization of Parathyroid Adenomas

There are multiple imaging modalities in primary hyperparathyroidism. Ultrasound examination and subtraction scintigraphy are usually the first-line imaging techniques. When these results are negative or inconsistent, additional [¹¹C]-methionine PET/CT (MET-PET/CT) or 4-dimensional computed tomography can be performed. ​This study aims to evaluate MET-PET/CT in comparison with other imaging techniques in primary hyperparathyroidism. This is a retrospective cohort study. Eighty-four patients with primary hyperparathyroidism, who underwent parathyroid surgery, were included. ​Imaging results have been correlated to the perioperative drop in parathyroid hormone level and to the pathological analysis. ​Descriptive statistics are used, supplemented with 95% Clopper-Pearson confidence intervals for sensitivity and specificity and a sub-analysis with the McNemar test on paired data only. The per-lesion sensitivity of MET-PET/CT seems higher than that of [^99mTc]-sestamibi or [^99mTc]-tetrofosmin and [^99mTc]-pertechnetate subtraction scintigraphy. The McNemar test, on paired data only, shows significantly higher sensitivity of MET-PET/CT compared to ultrasound (p=0.039) and significantly higher specificity of ultrasound compared to subtraction scintigraphy (p=0.035).​ MET-PET/CT after inconclusive or negative ultrasound and/or subtraction scintigraphy has an additional value in 70% of the cases.​ Preoperative parathyroid hormone levels were higher in patients in whom MET-PET/CT correctly predicted the pathological parathyroid glands, compared to those where MET-PET/CT missed at least one adenoma. The same trend was seen for 4-dimensional computed tomography. In conclusion, MET-PET/CT seems a valuable imaging modality in primary hyperparathyroidism, at least as second line imaging approach, with a higher per-lesion sensitivity than ultrasound in such setting. Especially when ultrasound and/or subtraction scintigraphy are inconclusive or negative, MET-PET/CT directs the surgeon to the correct localization of the parathyroid adenoma.

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.

Management of primary and renal hyperparathyroidism: guidelines from the German Association of Endocrine Surgeons (CAEK)

BACKGROUND AND AIMS

The purpose of this review is to provide updated recommendations for the surgical management of primary (pHPT) and renal (rHPT) hyperparathyroidism, formulating a new guideline of the German Association of Endocrine Surgeons (CAEK).

METHODS

Evidence-based recommendations for the diagnosis and therapy of pHPT and rHPT were assessed by a multidisciplinary panel using PubMed for a comprehensive literature search together with a structured consensus dialogue (S2k guideline of the Association of the German Scientific Medical Societies, AWMF).

RESULTS

During the last 20 years, a variety of new preoperative localization procedures, such as sestamibi-SPECT, 4D-CT, and various PET/CT procedures, were established for pHPT. High-resolution imaging, together with intraoperative parathyroid hormone (IOPTH) measurement, enabled focused or minimally invasive surgery to become the most favored surgical technique. Patients with pHPT and nonlocalizing imaging have a higher risk of multiglandular disease. Surgical therapy provides very high cure rates, with a clear relation to the surgeon's experience in parathyroid procedures. Reoperative parathyroidectomy, children with pHPT or familial forms, and parathyroid carcinoma are addressed and require special surgical expertise. A multidisciplinary team of experienced nephrologists, transplant, and endocrine surgeons should assess the diagnosis and treatment of renal HPT.

CONCLUSION

Surgery is the only curative treatment for pHPT and should be considered for all patients with pHPT. For rHPT, a more selective approach is required, and parathyroidectomy is indicated only when conservative treatment options fail. In parathyroid carcinoma, the adequacy of local resection influences local disease control.

Differences in Primary Hyperparathyroidism Between Pre- and Postmenopausal Women in India

OBJECTIVE

Primary hyperparathyroidism (PHPT) is a common endocrine disorder in women which becomes more prevalent after menopause. In this study, we compared the demographic, clinical, and biochemical variables between premenopausal (pre-M) and postmenopausal (post-M) women with PHPT.

METHODS

A retrospective analysis (from 2005 to 2019) of enrolled women PHPT patients from an online Indian PHPT registry.

RESULTS

Of the women with PHPT, 232 and 122 were pre-M and post-M, respectively. The number of post-M PHPT cases registered had a 3.3-fold increase in 2015-2019 from 2005-2009 compared with only a 2.5-fold increase in pre-M cases in the same duration. The majority were symptomatic (90%), although pre-M had a higher proportion of symptomatic than post-M (92% vs 85%; P = .04). Pre-M women showed more prevalence of osteitis fibrosa cystica than post-M women (28% vs 13%; P = .03), although hypertension and gallstone disease were seen more frequently in post-M PHPT women. Pre-M women had a significantly higher median PTH (403 vs 246 pg/mL; P = .02) and median alkaline phosphatase (202 vs 145 pg/mL; P = .02) than post-M women, and vitamin D deficiency was more common in pre-M women (58% vs 45%; P = .03). Gland localization, tumor weight, and disease cure rates did not differ according to menopausal status.

CONCLUSION

PHPT was more prevalent in pre-M women, although the number of post-M cases had significantly increased in the last 10 years. Pre-M women had generally more severe clinical and biochemical variables than post-M PHPT women.

Evaluating distal renal tubular acidification function in primary hyperparathyroidism and its effects on bone mineral density

Background

Primary hyperparathyroidism (PHPT) is a common endocrinopathy that may increase fracture risk and decrease bone mineral density (BMD). Some patients develop distal renal tubular acidification dysfunction under conditions of hyperchloraemia or hyperchloraemic acidosis. To examine whether this dysfunction influences the clinical outcome, we explored the distal renal tubular acidification function in patients with PHPT and its effects on the clinical manifestations of the disease.

Methods

We retrospectively analysed 75 PHPT patients with regard to renal tubular acidification and blood gas analysis. The patients were divided into two groups, the renal tubular acidification dysfunction group and normal function group.

Results

Serum phosphate level and total hip bone density were significantly decreased and 25OHD level was significantly increased in the renal tubular acidification dysfunction group in comparison to the normal function group. Female patients in the renal tubular acidification dysfunction group showed significantly decreased femoral neck and total hip BMD and increased susceptibility to fracture. However, there were no such differences in male patients between the two groups.

Conclusions

About 54.6 % of PHPT patients in our study population had abnormal distal renal tubular acidification. PHPT patients with abnormal distal renal tubular acidification may have lower hip bone density. Female PHPT patients with abnormal distal renal tubular acidification showed increased susceptibility to fractures and the development of osteoporosis.

Gender differences in the presentation, course and outcomes of primary hyperparathyroidism

OBJECTIVE

To investigate gender-associated differences in the presentation, course, and outcomes of primary hyperparathyroidism (PHPT).

STUDY DESIGN

A retrospective institutional cohort.

METHODS

The database of a tertiary endocrine institute was retrospectively screened for patients treated for PHPT in 2010-2018. Clinical, biochemical, and imaging data were collected. Presentation, management, and outcome variables were compared by gender and by age at diagnosis (<50/≥50 years).

RESULTS

The cohort included 182 women and 161 men diagnosed with PHPT at age 57.6 ± 12.8 and followed for 6.3 ± 5.5 years. There were no gender differences in age at detection of hypercalcemia and basal levels of serum and urinary calcium, serum PTH, and serum 25-hydroxyvitamin D. Men had a higher prevalence of nephrolithiasis (33 % vs 21 %, p = 0.01). Women had a higher frequency of osteoporosis (65 % vs 45 %, p < 0.001), and a lower mean lumbar spine T-score at PHPT diagnosis. At last follow-up, women had worse bone mineral density (BMD) results in all measured sites (lumbar spine, femoral neck, distal radius) and more fractures (34 % vs 20 %, p = 0.004), despite more frequent and longer pharmacological treatment of osteoporosis. On analysis by age, all these gender-associated differences were statistically significant only in patients diagnosed at age ≥50 years. Parathyroidectomy was performed in 52 % of women and 42 % of men (p = 0.06).

CONCLUSION

The main differences between male and female patients with PHPT are the higher prevalence, more intensive pharmacological treatment, and worse outcomes of osteoporosis in women. Tailoring the optimal medical and/or surgical treatment for fracture prevention in patients with PHPT remains a major challenge, especially in older women.

Radiologic Manifestation of Bone Involvement in Primary Hyperparathyroidism: Prevalence and Clinical Significance in a Southern European Series

OBJECTIVE

Clinically overt symptomatic bone disease in primary hyperparathyroidism (PHPT) is rarely seen today, and osteoporosis is the dominant finding. Subperiosteal bone resorption in the fingers and skull mottling are typical bone PHPT findings, the contemporary prevalence of which is unknown. We evaluated these mild lesions and investigated the impact of their occurrence on PHPT clinical management.

METHODS

We evaluated retrospectively a monocentric series of 363 PHPT patients classified in Group 1 (n = 100) or Group 2 (n = 263) according to the presence or absence of bone involvement, respectively. Patients belonging to Group 1, in turn, were subdivided into Group 1A, with severe and symptomatic lesions (n = 48), and Group 1B, with milder signs of osteitis fibrosa cystica (OFC) without brown tumors or fractures (n = 52).

RESULTS

Serum total and ionized calcium, parathyroid hormone, osteocalcin, alkaline phosphatase, and its bone fraction levels were higher in Group 1 than in Group 2, while no gender or age differences were observed between the groups. Osteoporosis prevalence was similar in Group 1B and Group 2 patients but lower than in Group 1A. Mild OFC findings did not modify the surgical indication in any patient of Group 1B.

CONCLUSION

Minor radiologic signs of OFC are not uncommon in the modern PHPT phenotype and occur in patients with more active disease. These signs could identify PHPT patients in an earlier stage of typical bone involvement. However, these features do not seem to upgrade either the clinical classification of asymptomatic PHPT patients or the propensity toward surgical choice.

Osteoporosis in Premenopausal Women: A Clinical Narrative Review by the ECTS and the IOF

CONTEXT

Consensus regarding diagnosis and management of osteoporosis in premenopausal women (PW) is still lacking due to few studies carried out in this population.

DESIGN

The European Calcified Tissue Society and the International Osteoporosis Foundation convened a working group to produce an updated review of literature published after 2017 on this topic.

RESULTS

Fragility fractures in PW are rare and mostly due to secondary osteoporosis (ie, in presence of an underlying disease such as hormonal, inflammatory, or digestive disorders). In absence of another disorder, low bone mineral density (BMD) together with fragility fractures qualifies as idiopathic osteoporosis. In contrast, low BMD alone does not necessarily represent osteoporosis in absence of bone microarchitectural abnormalities. BMD increases in PW with osteoporosis when the underlying disease is treated. For example, in celiac disease, an increase of 9% in radius trabecular volumetric density was achieved after 1 year of gluten-free diet, while anti-tumor necrosis factor alpha improved BMD in PW with inflammatory bowel diseases. In amenorrhea, including anorexia nervosa, appropriately delivered estrogen replacement therapy can also improve BMD. Alternatively, antiresorptive or anabolic therapy has been shown to improve BMD in a variety of conditions, the range of improvement (3%-16%) depending on skeletal site and the nature of the secondary cause. No studies were powered to demonstrate fracture reduction. The effects of bisphosphonates in childbearing women have been scantly studied and caution is needed.

CONCLUSION

The majority of PW with osteoporosis have an underlying disease. Specific therapy of these diseases, as well as antiresorptive and anabolic drugs, improve BMD, but without evidence of fracture reduction.

Circulating fractures-related microRNAs distinguish primary hyperparathyroidism-related from estrogen withdrawal-related osteoporosis in postmenopausal osteoporotic women: A pilot study

Primary hyperparathyroidism (PHPT) represents a common cause of secondary osteoporosis in postmenopausal women, where the negative effect of estrogen withdrawal and that of hyperparathyroidism on bone mineralization coexist. Circulating microRNAs (miRNAs) expression profile has been correlated to both osteoporosis and fragility fractures. The study aimed to profile a set of miRNAs associated with osteoporotic fractures, namely miR-21-5p, miR-23a-5p, miR-24-2-5p, miR-24-3p, miR-93-5p, miR-100-5p, miR-122-5p, miR-124-3p, miR-125b-5p and miR-148-3p, in the plasma of 20 postmenopausal PHPT women. PHPT miRNAs profiles were compared with those detected in 10 age-matched postmenopausal non-PHPT osteoporotic women (OP). All the 10 miRNAs were detected in the plasma samples of both PHPT and OP women. The miRNA profiles clearly distinguished PHPT from OP samples, and identified within the PHPT group, two clusters differing for the PHPT severity, in term of ionized calcium and bone mineralization. In particular, miR-93-5p was significantly downregulated in PHPT samples, while miR-24-3p negatively correlated with the T-score at lumbar, femur neck and total hip sites. PHPT women who experienced osteoporotic fractures had plasma miR-24-3p levels higher than those detected in unfractured PHPT women. In conclusion, PHPT may modulate circulating fractures-related miRNAs, in particular, miR-93-5p, which may distinguish estrogen-related from PHPT-related osteoporosis.

Physical Activity-Dependent Regulation of Parathyroid Hormone and Calcium-Phosphorous Metabolism

Exercise perturbs homeostasis, alters the levels of circulating mediators and hormones, and increases the demand by skeletal muscles and other vital organs for energy substrates. Exercise also affects bone and mineral metabolism, particularly calcium and phosphate, both of which are essential for muscle contraction, neuromuscular signaling, biosynthesis of adenosine triphosphate (ATP), and other energy substrates. Parathyroid hormone (PTH) is involved in the regulation of calcium and phosphate homeostasis. Understanding the effects of exercise on PTH secretion is fundamental for appreciating how the body adapts to exercise. Altered PTH metabolism underlies hyperparathyroidism and hypoparathyroidism, the complications of which affect the organs involved in calcium and phosphorous metabolism (bone and kidney) and other body systems as well. Exercise affects PTH expression and secretion by altering the circulating levels of calcium and phosphate. In turn, PTH responds directly to exercise and exercise-induced myokines. Here, we review the main concepts of the regulation of PTH expression and secretion under physiological conditions, in acute and chronic exercise, and in relation to PTH-related disorders.

Gender Predilection in Sporadic Parathyroid Adenomas

Primary hyperparathyroidism is a common endocrinopathy that is mainly caused by benign parathyroid adenomas. The frequency, clinical presentation and complications of the disease show significant differences between genders, with the majority of cases being reported in postmenopausal women. Due to this gender predilection, several studies have investigated the role of sex hormones in the pathogenesis of the disease and their potential use as targets for optimal and gender-specific management. Epigenetic mechanisms that regulate gene transcription may also contribute to these differences between genders. In this review, we outline what is currently known regarding the role of sex hormones and the recent data on the role of non-coding RNAs in the differences between genders in primary hyperparathyroidism due to sporadic parathyroid adenomas.

Non-surgical management of primary hyperparathyroidism in the aging population

Primary hyperparathyroidism (PHPT) is commonly observed in the aging population, and the average age at diagnosis has increased in the last 20 years. Parathyroidectomy, the only definitive cure for PHPT, is indicated in symptomatic and asymptomatic older PHPT patients with skeletal and renal disease. It is as effective in older patients as it is in younger patients. Nevertheless, older patients may present with comorbidities and greater frailty, leading to the possibility of more complications, higher morbidity and mortality after surgery. This review focuses on the non-surgical clinical management of PHPT in elderly patients. We also summarize the most recent literature regarding the pharmacological management of PHPT to reduce serum calcium levels, to improve bone mineral density or to do both in the aging population.

Symptoms of Primary Hyperparathyroidism in Men and Women: The Same but Different?

INTRODUCTION AND OBJECTIVE

Typical symptoms for primary hyperparathyroidism (pHPT) include osteoporosis, bone or joint pain, and nephrolithiasis, as well as fatigue, depression, gastritis, and cardiovascular disease. The female:male ratio was 3:1. The aim of this retrospective study was to evaluate the possible influence of gender-specific aspects of these symptoms.

METHODS

From February 2018 to November 2019, parathyroid surgery was performed in 125 patients with pHPT (age: 23-83 years); 95 (76%) were female, and 30 (24%) were male. Preoperatively, a standardized medical history including 7 typical symptoms of pHPT was used for routine clinical documentation according to the StuDoQ Thyroid and Parathyroid Registry.

RESULTS

For both groups (mean age: 60.4 years for females and 60.2 years for males), no sex differences were found in serum calcium or parathyroid hormone levels. For females, there was a tendency towards smaller hyperfunctioning parathyroid glands (16.8 vs. 20.5 mm) with less weight (1.14 vs. 1.52 g) and multiglandular disease. Nephrolithiasis was significantly more frequent in men than in women (36.7 vs. 16.8%, respectively; p = 0.036), but the difference in hypertension was not significant (60% in men vs. 47.4% in women, p = 0.230). Women reported significantly more often bone and joint pain (44.2% in women vs. 20% in men, p = 0.053) and depressive episodes (32.6% in women vs. 10% in men, p = 0.016).

CONCLUSION

91.2% of patients transferred for parathyroidectomy described typical symptoms of pHPT. However, an unexpected high gender difference was found following the analysis of symptoms documented in the StuDoQ Registry.

Primary hyperparathyroidism: a retrospective study over 18 years in an oncology center

Aim: To study primary hyperparathyroidism (pHPT) in an oncology center, including its possible association with malignancy and ionizing radiation. Methods: Retrospective analysis of 188 patients with sporadic pHPT treated with parathyroidectomy between 2000 and 2018. We studied the etiology, clinical and biochemical features of pHPT, history of malignancies and exposure to radiotherapy. Results: pHPT was caused by parathyroid adenoma in 90.4%, hyperplasia in 5.3% and carcinoma in 4.3%. Cure and recurrence rates of pHPT were 99 and 4.3%, respectively. Median follow-up time was 19 months. Prevalence of malignancies was 30%, mostly thyroid and breast cancer. Radiotherapy of the head, neck or thorax (8.5%) was not associated with worse hypercalcaemia or recurrence. Males had larger adenomas, higher calcium and parathyroid hormone (p < 0.01). Conclusion: Prevalence of parathyroid carcinoma and other malignancies was higher than reported in other studies. Ionizing radiation exposure was unrelated with pHPT severity. Men had more severe pHPT. High cure and low recurrence rates were achieved.

Clinical Presentation of Primary Hyperparathyroidism in Older Adults

Background

The clinical presentation of primary hyperparathyroidism (PHPT) has changed greatly during the past few decades. Our aim was to evaluate whether the clinical presentation at diagnosis differed according to age.

Methods

We evaluated retrospectively a monocentric series of 462 consecutive patients with PHPT, dividing them according to a cutoff of 65 years of age.

Results

No differences were found in the mean serum PTH, calcium, or vitamin D levels. In older patients (n = 212; 45.9%), the urinary calcium levels were significantly lower (median, 205 mg/24 hour; interquartile range, 220 mg/24 hour) compared with those in younger patients (median, 308 mg/24 hour; interquartile range, 233 mg/24 hour). In addition, renal involvement was significantly less frequent (25% vs 49.2%), and bone involvement significantly more frequent (58% vs 44%) in older patients compared with younger patients. The clinical presentation was significantly different between the two age groups, with a lower frequency of symptomatic forms and a greater frequency of asymptomatic forms not meeting surgical criteria in the older patients (44.4% vs 57.2% and 18.4% vs 5.6%, respectively). Osteoporosis was significantly more frequent in the older adults than in their younger counterparts. The most affected bone site was the forearm in older adults and the lumbar spine in younger ones (50.3% and 50.5%, respectively).

Conclusion

The clinical presentation of PHPT differs according to age, and this difference can affect the selection of management modalities.

UNKNOWN AND ALREADY KNOWN THYROID ABNORMALITIES IN PRIMARY HYPERPARATHYROIDISM

OBJECTIVE

Primary hyperparathyroidism (PHPT) and thyroid diseases are highly prevalent in the general population, but the putative link between the 2 conditions remains unclear.

METHODS

A monocentric consecutive series of 434 patients with PHPT was retrospectively evaluated by lab and ultrasonography to look for thyroid abnormalities. Patients were classified in 3 groups: without thyroid abnormalities (group 1, n = 171), with thyroid diseases not previously known (group 2a, n = 69), and thyroid diseases previously known (group 2b, n = 194).

RESULTS

In terms of thyroid disease, no significant difference was found between groups 2a and 2b, except for the significantly larger number of patients with toxic nodular goiter in group 2b. PHPT was more frequently symptomatic in group 2a than in group 2b, despite no differences in serum calcium, creatinine, parathyroid hormone (PTH), or 25-hydroxyvitamin D (25OHD) levels.

CONCLUSION

A total of 60% of PHPT patients had a thyroid disease that was unknown prior to PHPT diagnosis in almost one-third of cases. The newly diagnosed and previously known thyroid diseases were similar, both mostly affecting postmenopausal females.

ABBREVIATIONS

Ab = antibody; aPHPT = asymptomatic PHPT; 25OHD = 25-hydroxyvitamin D; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; Tg = thyroglobulin; TPO = thyroperoxidase; TSH = thyroid-stimulating hormone; US = ultrasound.

Classical complications of primary hyperparathyroidism

Traditionally, classical complications of primary hyperparathyroidism are mainly represented by skeletal, kidney and gastrointestinal involvement. The old picture of osteitis fibrosa cystica is no longer commonly seen, at least in the western world. However, new imagining techniques have highlighted deterioration of skeletal tissue in patients with primary hyperparathyroidism not captured by traditional DXA measurement. Concerning the kidney, the most common consequences of excessive parathyroid hormone secretion are hypercalciuria and kidney stones; however, the exact pathogenesis of urinary stone formation is still unknown. The 2013 International Congress on the management of Asymptomatic Primary Hyperparathyroidism, emphasized the role of imaging techniques for early discovery of both skeletal and renal complications in asymptomatic patients. Gastrointestinal manifestations include acid-peptic disease, constipation, pancreatitis and gall stone disease. More studies are needed in this area to find the exact pathophysiological mechanism underlying these manifestations and the effect of parathyroid surgery.

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.

Comparison of Initial Clinical Presentations between Primary Hyperparathyroidism Patients from New Brunswick and Changsha

PURPOSE

To compare the initial clinical features, laboratory values, and bone mineral density among patients with primary hyperparathyroidism (PHPT) in Changsha (China) and New Brunswick (USA).

METHODS

In this retrospective study, we reviewed 169 PHPT patients who presented at Robert Wood Johnson University Hospital and 133 PHPT patients who presented at the Second Xiangya Hospital of Central South University in the same time period. The following characteristics were compared between the groups: age, gender, BMI, serum calcium, alkaline phosphatase (AKP), albumin, intact PTH (iPTH), 25-hydroxyvitamin D (25 (OH) D), fasting blood glucose levels, and bone mineral density (BMD). All these parameters were also compared according to gender and menopausal status. iPTH associations were also assessed along with several other parameters.

RESULTS

PHPT patients from Changsha had higher serum calcium, iPTH, and AKP levels but lower 25 (OH) D levels than the patients from New Brunswick (p < 0.05). Patients in Changsha had lower T-scores and Z-scores in both the lumbar spine and hip regions than those in New Brunswick (p < 0.05). Patients in New Brunswick had lower percentages of parathyroid adenoma and kidney stones. Serum iPTH level was positively correlated with serum calcium and serum AKP levels in both Changsha and New Brunswick (p < 0.05).

CONCLUSIONS

There are distinct biochemical and clinical differences between patients with PHPT in China and the United States. Our study revealed that Asian PHPT patients from Changsha presented more severe PHPT profiles, lower bone mineral density, and higher incidence of renal stones.