Prevalence of Primary Hyperparathyroidism and Impact on Bone Mineral Density in Elderly Men: MrOs Sweden

Double Parathyroid Adenoma Presenting as One Mass: A Case Report

Background and Objectives

Primary hyperparathyroidism is a common endocrinological condition, which is usually caused by solitary parathyroid adenoma. The aim of this article is to present a case of double adenoma presenting as one and literature review on this topic.

Case presentation

56 years old female suffering from generalized fatigue, bone pain, unstable body weight and palpitations was diagnosed with primary hyperparathyroidism. Further investigation revealed elevated parathyroid hormone (PTH), ionized and total calcium levels. Imaging showed two adenomas merging into one. Parathyroidectomy was performed and final intraoperative PTH (IOPTH) decreased by 71.6%. Parathyroid adenoma measuring 40 mm x 15 mm x 11 mm and weighing 1 g 483 mg was excised. 7 weeks after surgery patient was feeling well but her PTH level was elevated again.

Conclusions

As far as we know, the double parathyroid adenoma presented in this case report is the largest reported in the Northern Europe and the first one that presents as one mass within the region. Double adenoma increases the risk of recurrent primary hyperparathyroidism (PHPT) and requires more careful and longer follow up after surgery than solitary adenomas. Final IOPTH must decrease by at least 50% within 10 minutes. This case shows that despite final IOPTH drop by more than 50%, after few weeks normocalcemic elevated parathyroid hormone (NCePTH) phenomenon was noticed. This phenomenon does not indicate surgical failure.

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 the geriatric population: A case report and mini literature review

We report a case of a 93-year-old woman with PHPT secondary to a left inferior parathyroid adenoma. The patient met criteria to be a surgical candidate; however, literature about parathyroidectomy in the elderly was limited and controversial. The patient remained stable through medical management for the next 5 years.

Genomic Analysis of Abnormal DNAM Methylation in Parathyroid Tumors

BACKGROUND

Parathyroid tumors are common endocrine neoplasias associated with primary hyperparathyroidism. Although numerous studies have studied the subject, the predictive value of gene biomarkers nevertheless remains low.

METHODS

In this study, we performed genomic analysis of abnormal DNA methylation in parathyroid tumors. After data preprocessing, differentially methylated genes were extracted from patients with parathyroid tumors by using t-tests.

RESULTS

After refinement of the basic differential methylation, 28241 unique CpGs (634 genes) were identified to be methylated. The methylated genes were primarily involved in 7 GO terms, and the top 3 terms were associated with cyst morphogenesis, ion transport, and GTPase signal. Following pathway enrichment analyses, a total of 10 significant pathways were enriched; notably, the top 3 pathways were cholinergic synapses, glutamatergic synapses, and oxytocin signaling pathways. Based on PPIN and ego-net analysis, 67 ego genes were found which could completely separate the diseased group from the normal group. The 10 most prominent genes included POLA1, FAM155 B, AMMECR1, THOC2, CCND1, CLDN11, IDS, TST, RBPJ, and GNA11. SVM analysis confirmed that this grouping approach was precise.

CONCLUSIONS

This research provides useful data to further explore novel genes and pathways as therapeutic targets for parathyroid tumors.

The association between Single Nucleotide Polymorphisms of Klotho Gene and Mortality in Elderly Men: The MrOS Sweden Study

The Klotho (KL) gene is involved in phosphate homeostasis. Polymorphisms in this gene have been reported to be associated with the risk of cardiovascular disease. Here we used computational tools to predict the damage-associated single nucleotide polymorphisms (SNPs) in the human KL gene. We further investigated the association of SNPs in the KL gene and mortality in the Swedish multicenter prospective Osteoporotic Fractures in Men (MrOS) cohort. This study included 2921 men (aged 69-81 years) with mean 4.49 ± 1.03 years follow-up. 18 SNPs in the KL gene were genotyped using Sequenom. These SNPs were identified by in silico tools for the coding and noncoding genome to predict the damaging SNPs. After quality analyses, SNPs were analyzed for mortality risk using two steps approach on logistic regression model screening and then Cox regression model confirmation. Two non-synonymous SNPs rs9536314 and rs9527025 were found to be potentially damaging SNPs that affect KL protein stability and expression. However, these two SNPs were not statistically significantly associated with all-cause mortality (crude Hazard ratio [HR] 1.72, 95% confidence interval [CI] 0.96-3.07 in rs9536314; crude HR 1.82, 95% CI 0.998-3.33 in rs9527025) or cardiovascular mortality (crude HR 1.52, 95% CI 0.56-4.14 in rs9536314; crude HR 1.54, 95% CI 0.55-4.33 in rs9527025) in additive model using Cox regression analysis. In conclusion, these two potentially damaging SNPs (rs9536314 and rs9527025) in the KL gene were not associated with all-cause mortality or cardiovascular mortality in MrOs cohort. Larger scales studies and meta-analysis are needed to confirm the correlation between polymorphisms of the KL gene and mortality.

Analysis of Bone Impairment by 3D DXA Hip Measures in Patients With Primary Hyperparathyroidism: A Pilot Study

CONTEXT

Primary hyperparathyroidism (PHPT) has been related to bone loss. Dual-energy x-ray absorptiometry (DXA) cannot distinguish between trabecular and cortical bone compartments but the recently developed three-dimensional (3D)-DXA software might overcome this issue.

OBJECTIVE

To examine the differences in DXA-derived areal bone mineral density (aBMD) and 3D-DXA parameters at the hip site between patients with PHPT and a healthy control group.

DESIGN

Cross-sectional pilot study.

SETTING

Hospital.

PATIENTS

80 adults (59.5 ± 9.1 yrs), 40 with PHPT and 40 age- and sex-matched healthy controls.

MEASURES

aBMD (g/cm2) of the femoral neck, trochanter, shaft, and total hip was assessed using DXA. Cortical surface (sBMD, mg/cm2), cortical volumetric BMD (vBMD, mg/cm3), trabecular vBMD (mg/cm3), integral vBMD (mg/cm3) and cortical thickness (mm) was assessed using 3D-DXA software.

RESULTS

Mean-adjusted values showed lower aBMD (7.5%-12.2%, effect size: 0.51-1.01) in the PHPT group compared with the control group (all P < 0.05). 3D-DXA revealed bone impairment (3.7%-8.5%, effect size: 0.47-0.65) in patients with PHPT, mainly in cortical parameters (all P < 0.05). However, differences in trabecular vBMD were not statistically significant (P = 0.055). The 3D mapping showed lower cortical sBMD, cortical vBMD, and cortical thickness at the trochanter and diaphysis in the PHPT group (P < 0.05) compared with the control group. In both groups, the presence of osteopenia or osteoporosis is related to lower cortical bone.

CONCLUSIONS

aBMD and cortical 3D parameters are impaired in patients with PHPT versus healthy controls. The vBMD of the trabecular compartment seems to be affected, although to a lesser extent.

The effect of parathyroidectomy on bone mineral density in primary hyperparathyroidism

Background/aim

This study aimed to investigate the change in bone mineral density (BMD) before and 1 year after parathyroidectomy in patients with primary hyperparathyroidism (PHPT).

Materials and methods

The clinical and biochemical parameters and DEXA screening of patients with symptomatic PHPT (n = 28) and asymptomatic PHPT (n = 63) were investigated before and 1 year after parathyroidectomy.

Results

Patients with symptomatic PHPT had a higher prevalence of nephrolithiasis (18.2% vs. 4.6%, P = 0.032) when compared to the prevalence in patients with asymptomatic PHPT. The prevalence of osteoporosis in the lumbar spine (63.0% vs. 37.5%, P = 0.026) and femoral neck (40.7% vs. 20.6%, P = 0.048) was higher in symptomatic PHPT when compared to the prevalence in asymptomatic PHPT. After parathyroidectomy, the decreases in the prevalence of osteoporosis in the lumbar spine (25.8% vs. 9.4%, P = 0.014), femoral neck (22.1% vs. 8.2%, P =0.009), and total hip (22.4% vs. 5.3%, P = 0.007) were higher in symptomatic PHPT compared to the asymptomatic PHPT group. A higher BMD gain (g/cm2) was seen in the lumbar spine (10.83% vs. 4.65%, P=0.016) and femoral neck (12.61% vs. 4.37%, P=0.005) in symptomatic PHPT compared to the asymptomatic PHPT group.

Conclusion

Parathyroidectomy provided more BMD gain in the lumbar spine and femoral neck in patients with symptomatic PHPT when compared to patients with asymptomatic PHPT 1 year after parathyroidectomy.

A defined human aging phenome

Aging is among the most complex phenotypes that occur in humans. Identifying the interplay between different age-associated features is undoubtedly critical to our understanding of aging and thus age-associated diseases. Nevertheless, what constitutes human aging is not well characterized. Towards this end, we mined millions of PubMed abstracts for age-associated terms, enabling us to generate a detailed description of the human aging phenotype. We discovered age-associated features in clusters that can be broadly associated with previously defined hallmarks of aging, consequently identifying areas where interventions could be pursued. Importantly, we validated the newly discovered features by manually verifying the prevalence of these features in combined cohorts describing 76 million individuals, allowing us to stratify features in aging that appear to be the most prominent. In conclusion, we propose a comprehensive landscape of human aging: the human aging phenome.

The natural history and hip geometric changes of primary hyperparathyroidism without parathyroid surgery

There have been few reports on changes in bone geometry in asymptomatic patients with primary hyperparathyroidism (PHPT) not treated surgically. We reviewed the records concerning biochemical parameters, bone mineral density (BMD), and hip geometry in 119 PHPT patients who did not undergo parathyroidectomy, followed up at one of three hospitals affiliated to Seoul National University from 1997 to 2013. We examined biochemical parameters over 7 years and BMD and hip geometry over 5 years of follow-up. We further compared hip geometry and BMD derived from dual-energy X-ray absorptiometry (DXA) between patients and age- and sex-matched controls. The median follow-up duration of 56 patients for whom surgery was not indicated was 33.9 months (range 11.2-131.2 months), and 19.6 % of these patients had disease progression during follow-up. Serum calcium levels remained stable for 7 years in all 119 patients. From a comparison of the PHPT patients for whom surgery was not indicated with controls, both male and postmenopausal female patients had significantly lower hip axis length (P < 0.001), cross-sectional moment of inertia (P < 0.001), cross-sectional area (P < 0.001), and section modulus (P < 0.001). In addition, cortical thickness was significantly decreased at 5 years compared with individual baseline values (P = 0.003). However, there was no significant change in BMD for the duration of the 5-year follow-up. DXA-derived geometry can detect skeletal change in asymptomatic PHPT patients for whom surgery is not indicated, supporting the concept that even mild PHPT can eventually compromise the cortical bones. Hip geometry is a potential tool for monitoring skeletal complication in asymptomatic PHPT patients.

Low serum iron is associated with high serum intact FGF23 in elderly men: The Swedish MrOS study

BACKGROUND

Fibroblast growth factor (FGF23) is a protein that is produced by osteoblasts and osteocytes. Increased serum levels of FGF23 have been associated with increased risks of osteoporotic fractures and cardiovascular disease, particularly in participants with poor renal function. Serum iron (Fe) has been suggested as a regulator of FGF23 homeostasis.

OBJECTIVE

To determine whether Fe and iron status are determinants of the levels of intact FGF23 (iFGF23) in elderly men.

METHODS

The MrOS study is a population-based study of elderly men (N=1010; mean age, 75.3years; range, 69-81years). The levels of Fe, transferrin saturation (TS), and ferritin were evaluated in relation to the serum concentrations of iFGF23 before and after adjustments for confounders.

RESULTS

TS <15% was found in 3.5% (34/977) of the participants, who had a higher median level iFGF23 compared with the remaining subjects (47.4μmol/L vs. 41.9μmol/L, p=0.008). The levels of iFGF23 correlated negatively (un-adjusted) with the levels of Fe (r=-0.17, p<0.001), TS (r=-0.16, p<0.001) and serum ferritin (r=-0.07, p=0.022). In addition, in participants with estimated glomerular filtration rate eGFRCystatin C>60mL/min, the levels of iFGF23 correlated (age-adjusted) negatively with the levels of Fe (r=-0.15, p<0.001) and TS (r=-0.17, p<0.001). The level of iFGF23 correlated positively (un-adjusted) with lumbar spine bone mineral density (BMD) (r=0.14, p<0.001), total body BMD (r=0.11, p=0.001), and total hip BMD (r=0.09, p=0.004). The corresponding correlations, when adjusted for age, weight, and height were: r=0.08, p=0.018; r=0.05, p=0.120; and r=0.02, p=0.624, respectively. No associations were found between BMD and the levels of Fe or TS. Multiple step-wise linear regression analyses [adjusting for age, body mass index (BMI), comorbidity index, cystatin C, C-reactive protein (hs-CRP), serum vitamin D 25-OH (25OHD), phosphate, calcium, parathyroid hormone (PTH), erythropoietin, hemoglobin, lumbar spine BMD, apolipoprotein B/A1 ratio] were performed in three separate models with Fe, TS or ferritin as potential explanatory variables. Fe and TS, but not ferritin, were independent predictors of iFGF23 level (standardized β-values: -0.10, p<0.001; -0.10, p<0.001; and -0.05, p=0.062, respectively).

CONCLUSION

Low levels of Fe in elderly men are associated with high levels of iFGF23, independently of markers of inflammation and renal function, suggesting an iron-related pathway for FGF23 regulation.

Parathyroidectomy for primary hyperparathyroidism in the elderly: experience of a single endocrine surgery center

BACKGROUND

Primary hyperparathyroidism is a common endocrine disease, and its incidence increases with age.

AIMS

Our aim was to retrospectively evaluate the impact of age on patient outcomes following parathyroidectomy for primary hyperparathyroidism.

METHODS

Two-hundred fifty-six consecutive patients undergoing parathyroidectomy with preoperative diagnosis of primary hyperparathyroidism were divided into three groups according to patient age: group A, ≤64 years; group B, 65-74 years; and group C, ≥75 years.

RESULTS

Thyroid disease was associated with the hyperparathyroidism in 44 patients (28.2%) in group A, 34 (44.7%) in B, and 10 (41.7%) in C (p < 0.01). Minimally invasive parathyroidectomy was performed in 104 patients (66.7%) in group A, 35 (46.1%) in B, and 8 (33.3%) in C (p < 0.01). Conversion to bilateral exploration was carried out in five cases in group A (4.6%), three in B (8.3%), and two in C (20%). Multiglandular disease was observed in six patients (3.8%) in group A, seven (9.2%) in B, and five (20.8%) in C (p = 0.012). Mean postoperative stay was similar between groups; no major complications and no cases of mortality occurred.

DISCUSSION

Multiglandular disease is more common in older patients than younger individuals, and minimally invasive approaches are less used in this patient group. Increased surgical risk and paucity of symptoms in these patients sometimes result in a delay in surgical treatment.

CONCLUSIONS

Parathyroidectomy is a safe and effective procedure to perform in elderly patients. Multiglandular disease was found to be more prevalent in older patients, but minimally invasive parathyroidectomy can be performed safely. Surgeons should consider parathyroidectomy in patients with primary hyperparathyroidism regardless of age.

Secondary osteoporosis and metabolic bone disease in patients 50 years and older with osteoporosis or with a recent clinical fracture: a clinical perspective

PURPOSE OF REVIEW

The purpose of this review is to provide guidance to clinicians about which laboratory tests should be performed in patients with osteoporosis or with a recent fracture.

RECENT FINDINGS

Newly diagnosed secondary osteoporosis and other metabolic bone diseases (SECOB) have been found in 5-48% of patients with osteoporosis. In patients with a recent fracture, new SECOB is found in 10-47% of patients with osteoporosis, and in 26-51% if all patients with a fracture regardless of bone mineral density (BMD) are screened. More than one SECOB can be found in the same patient, even when they have already known SECOB. In primary hyperparathyroidism, hyperthyroidism, hypercortisolism, and multiple myeloma, both SECOB and its treatment have an impact on BMD and fractures. For other SECOBs, no treatment is available, or there are no data about the effect of treatment of the SECOB on BMD and fractures.

SUMMARY

We recommend performing the following tests in all patients with osteoporosis or a recent clinical fracture: calcium, phosphate, creatinine, albumin, erythrocyte sedimentation rate in all patients, 24 h urine calcium in men and serum testosterone in men less than 70 years. On indication, additional tests can be performed.

Characteristics of hyperparathyroid states in the Canadian multicentre osteoporosis study (CaMos) and relationship to skeletal markers

CONTEXT

PTH is an essential regulator of mineral metabolism; PTH hypersecretion may result in hyperparathyroidism including normocalcaemic, primary and secondary hyperparathyroidism.

OBJECTIVE

To examine the characteristics of participants with hyperparathyroid states and the relationship to bone mineral density (BMD).

DESIGN AND PARTICIPANTS

A cross-sectional study of 1872 community-dwelling men and women aged 35+ years (mostly Caucasian) with available serum PTH from Year 10 Canadian Multicentre Osteoporosis Study follow-up (2005-07). PTH was determined using a second-generation chemiluminescence immunoassay.

OUTCOME MEASURES

L1-L4, femoral neck and total hip BMD.

RESULTS

We established a PTH reference range (2·7-10·2 pmol/l) based on healthy participants (i.e. normal serum calcium, serum 25-hydroxyvitamin D, kidney function and body mass index, who were nonusers of antiresorptives, glucocorticoids and diuretics and not diagnosed with diabetes or thyroid disease). Participants with PTH levels in the upper reference range (5·6-10·2 pmol/l), representing a prevalence of 10·7%, had lower femoral neck and total hip BMD, by 0·030 g/cm(2) [95% confidence interval: 0·009; 0·051] and 0·025 g/cm(2) (0·001; 0·049), respectively, than those with levels 2·7-5·6 pmol/l. Participants with normocalcaemic and secondary hyperparathyroidism also had lower total hip BMD than those with levels 2·7-5·6 pmol/l, and CaMos prevalences of normocalcaemic, primary and secondary hyperparathyroidism were 3·3%, 1·4% and 5·2%, respectively.

CONCLUSION

We found reduced BMD in participants with accepted hyperparathyroid states but also a notable proportion of other participants that might benefit from having lower PTH levels.

Diagnosis and management of primary hyperparathyroidism--a scientific statement from the Department of Bone Metabolism, the Brazilian Society for Endocrinology and Metabolism

OBJECTIVE

To conduct a literature review on the diagnosis and management of primary hyperparathyroidism including the classical hipercalcemic form as well as the normocalcemic variant.

MATERIALS AND METHODS

This scientific statement was generated by a request from the Brazilian Medical Association (AMB) to the Brazilian Society for Endocrinology as part of its Clinical Practice Guidelines program. Articles were identified by searching in PubMed and Cochrane databases as well as abstracts presented at the Endocrine Society, Brazilian Society for Endocrinology Annual Meetings and the American Society for Bone and Mineral Research Annual Meeting during the last 5 years. Grading quality of evidence and strength of recommendation were adapted from the first report of the Oxford Centre for Evidence-based Medicine. All grades of recommendation, including "D", are based on scientific evidence. The differences between A, B, C and D, are due exclusively to the methods employed in generating evidence.

CONCLUSION

We present a scientific statement on primary hyperparathyroidism providing the level of evidence and the degree of recommendation regarding causes, clinical presentation as well as surgical and medical treatment.

Sporadic primary hyperparathyroidism: medical and surgical updates

This review discusses recent findings on the clinical presentation, evaluation, medical and surgical management of primary hyperparathyroidism. Medical management includes the use of cinacalcet and bisphosphonates for bone loss and correction of vitamin D deficiency. Surgical updates reviewed recent studies on the preoperative localization of the disease, specifically, sestamibi scans, 4DCT and MRI. Focused parathyroidectomy continues to be the preferred surgical approach for a select group of patients, guided by intraoperative use of PTH and new technology, such as endoscopic and robotic platforms; however, there appears to be no difference in long-term success compared to the traditional approach.

Holotranscobalamin is not influenced by decreased renal function in elderly men: the MrOS Sweden study

BACKGROUND

Subclinical cobalamin deficiency is common in the elderly, but the sensitivity and specificity of serum total cobalamin for this diagnosis is poor. Serum holotranscobalamin (holoTC), a measure of biologically available cobalamin, is considered a better marker for early cobalamin depletion than total cobalamin. However, in elderly populations, health-related reference intervals for holoTC and correlations to renal function are not entirely clear.

METHODS

HoloTC was determined with an automated microparticle enzyme immunoassay (AxSYM®) in 790 elderly non-vitamin-supplemented Swedish men, median age 75.3 years. Renal function was assessed with creatinine, cystatin C and estimated glomerular filtration rate (eGFR calculated from creatinine).

RESULTS

Median holoTC was 51.8 pmol/L, the health-related reference interval 19.6-132.3 pmol/L. There was no significant difference in mean holoTC in probands with normal compared to high creatinine (P = 0.80) and cystatin C (P = 0.82). No significant differences between the quartiles of creatinine or cystatin C in mean of log holoTC were seen. HoloTC correlated strongly with total cobalamin (r = 0.69, P < 0.001), weaker with eGFRcreatinine (r = -0.09, P < 0.05) and creatinine (r = 0.09, P < 0.05), the latter correlation was only seen in subjects with creatinine <100 µmol/L. HoloTC correlated negatively with plasma total homocysteine (r = -0.24, P < 0.001), but not with cystatin C and age.

CONCLUSIONS

Serum holoTC in healthy elderly men shows the same distribution as earlier described for a younger reference population. In this group of elderly subjects, holoTC did not correlate to reduced renal function. Thus, holoTC appears to be a promising tool for evaluating cobalamin status also in elderly populations.

Skeletal effects of primary hyperparathyroidism: bone mineral density and fracture risk

Parathyroid hormone (PTH) is associated with anabolic and catabolic skeletal effects that vary according to the kinetics of serum levels and the type of bone. The anabolic effects are manifested in patients with a periodic rapid transient rise in serum PTH, as seen with daily subcutaneous injection of PTH(1-34) and PTH(1-84) in the treatment of osteoporosis. These patients have an increase in bone mineral density (BMD), particularly at skeletal sites with a high trabecular component, such as the lumbar spine, and a reduction in fracture risk. The catabolic effects are typified in patients with primary hyperparathyroidism (PHPT) who have chronic persistently elevated PTH levels. Patients with long-standing PHPT have a reduction in BMD, particularly at predominately cortical skeletal sites, such as the one-third radius, with relative preservation of BMD at the lumbar spine. Some but not all studies have reported an increase in fracture risk with PHPT. Because many patients with PHPT are postmenopausal women at risk for osteoporosis owing to estrogen deficiency, BMD and fracture risk may be a result of multiple factors with variable effects on bone remodeling. The skeletal effects of normocalcemic PHPT have not yet been fully characterized, but may not be the same as hypercalcemic PHPT.

Renal stones and calcifications in patients with primary hyperparathyroidism: associations with biochemical variables

OBJECTIVE

To study the prevalence of renal stones and nephrocalcinosis in patients with primary hyperparathyroidism (PHPT) and to appraise biochemical variables as risk factors for developing renal calcifications.

DESIGN

Cross-sectional.

MATERIALS AND METHODS

All patients (n=177) undergoing diagnostic evaluation and surgery for PHPT at Aarhus University Hospital between 2007 and 2009. All patients underwent routine spiral CT scans of the abdomen to determine the presence or absence of renal calcifications.

RESULTS

A total of 45 patients (25.4%, 95% confidence intervals: 19.0-31.4%) had renal stones (15.3%) and/or renal calcifications (10.2%) on the CT scans. Compared with those without calcification (n=132), the group with calcification had a significantly lower plasma creatinine level (67.0±25.1 vs 74.6±17.5 μmol/l, 2P=0.03). Moreover, CaE was higher in PHPT patients with renal calcification than in PHPT patients without (0.91±0.28 vs 0.74±0.40 mmol/mmol, 2P=0.02). The other measured or derived biochemical variables were similar in the two groups. No biochemical variable was predictive for renal calcifications in a multiple regression analysis.

CONCLUSION

We found a high prevalence of renal calcifications among PHPT patients but no deterioration of renal function. The occurrence of calcifications was related to low plasma creatinine and a high urine calcium/creatinine ratio. However, biochemical markers in general were poor predictors for the risk of renal stones or nephrocalcinosis indicating that routine image diagnostics may be needed for the identification of these complications in order to establish indication for surgery and ensure proper treatment.

[Clinical practice guidelines for evaluation and treatment of osteoporosis associated to endocrine and nutritional conditions. Bone Metabolism Working Group of the Spanish Society of Endocrinology]

OBJECTIVE

To provide practical recommendations for evaluation and treatment of osteoporosis associated to endocrine diseases and nutritional conditions.

PARTICIPANTS

Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology, a methodologist, and a documentalist.

METHODS

Recommendations were formulated according to the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed), using the following terms associated to the name of each condition: AND "osteoporosis", "fractures", "bone mineral density", and "treatment". Papers in English with publication date before 18 October 2011 were included. Current evidence for each disease was reviewed by two group members, and doubts related to the review process or development of recommendations were resolved by the methodologist. Finally, recommendations were discussed in a meeting of the Working Group.

CONCLUSIONS

The document provides evidence-based practical recommendations for evaluation and management of endocrine and nutritional diseases associated to low bone mass or an increased risk of fracture. For each disease, the associated risk of low bone mass and fragility fractures is given, recommendations for bone mass assessment are provided, and treatment options that have shown to be effective for increasing bone mass and/or to decreasing fragility fractures are listed.

Current evidence for recommendation of surgery, medical treatment and vitamin D repletion in mild primary hyperparathyroidism

Management of patients with mild primary hyperparathyroidism (PHPT) has been widely discussed because most patients today do not have specific symptoms. While surgery is always an option, the recommendations for treatment have shifted, which mostly reflects changes in clinical practice. In this study, we aimed to evaluate evidence for the current recommendations concerning operation vs observation, repletion with vitamin D (VitD) and alternative medical management. Surgery is followed by normalisation of calcium and parathyroid hormone (PTH) and a decrease in bone turnover followed by an increase in bone mass. It is not known what the consequences would be for the frequency of fractures. Randomised studies have indicated beneficial effects of operation on quality of life (QoL), but the effects have been minor and inconsistent. Operation seems not to be superior to observation for cardiovascular risk factors. Although PHPT patients in average have slightly decreased plasma 25OH VitD, severe symptomatic VitD deficiency seems not to be a characteristic of PHPT patients in Europe. However, if present, we recommend VitD substitution before final decision on surgical treatment. It is unknown whether routine VitD supplementation should be offered preoperatively to all patients with mild PHPT or as part of long-term medical treatment. Targeted medical management could be an option for patients with contraindications to surgery. Antiresorptive therapy might be appropriate for patients with a low bone mass to prevent further bone loss. Calcimimetics could be tried to control serum calcium levels although there is no evidence of an effect on the hypercalcaemic symptoms or the QoL. Combined therapy with calcimimetics and alendronate could be considered for patients with hypercalcaemia and overt bone disease.

The DNA methylome of benign and malignant parathyroid tumors

The role of DNA methylation of CpG islands in parathyroid tumorigenesis has not been analyzed in an unbiased, systematic fashion. DNA was isolated from normal and pathologic parathyroid tissues, bisulphite modified and analyzed using the Infinium HumanMethylation27 BeadChip. Distinct hierarchical clustering of genes with altered DNA methylation profiles in normal and pathologic parathyroid tissue was evident. Comparing normal parathyroid tissue with parathyroid adenomas, 367 genes were significantly altered, while 175 genes significantly differed when comparing parathyroid carcinomas and normal parathyroid tissues. A comparison between parathyroid adenomas and parathyroid carcinomas identified 263 genes with significantly distinct methylation levels. Results were confirmed for certain genes in a validation cohort of 40 parathyroid adenomas by methylation-specific PCR. Genes of known or putative importance in the development of parathyroid tumors showed significant and frequent hypermethylation. DNA hypermethylation of CDKN2B, CDKN2A, WT1, SFRP1, SFRP2, and SFRP4 was associated with reduced gene expression in both benign and malignant parathyroid tumors. Treatment with 5-aza-2'-deoxycytidine of primary cell cultures restores expression of hypermethylated genes in benign and malignant parathyroid tumors. In conclusion, the unbiased, genome-wide study of the parathyroid tumor DNA methylome identified a number of genes with altered DNA methylation patterns of putative importance to benign and malignant parathyroid tumorigenesis.