Effect of surgery on cardiovascular risk factors in mild primary hyperparathyroidism

Skeletal Effect of Parathyroidectomy on Patients With Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis

CONTEXT

Parathyroidectomy (PTX) is recommended for curing primary hyperparathyroidism (PHPT), although uncertainty remains regarding the extent of fracture risk reduction following surgery.

OBJECTIVE

This work aimed to compare fracture risk and bone mineral density (BMD) changes in patients with PHPT undergoing PTX vs observation (OBS).

METHODS

We systematically searched PubMed, Embase, and the Cochrane Library until September 2022, including randomized controlled trials (RCTs) and cohort studies, and reviewed citations from previous reviews. Among 1260 initial records, 48 eligible articles from 35 studies (5 RCTs; 30 cohorts) included PHPT patients receiving PTX or OBS interventions with reported fracture events at any site, including the hip, spine, or forearm, and/or BMD changes at each location. Data extraction followed Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines by 2 independent reviewers.

RESULTS

In 238 188 PHPT patients (PTX: 73 778 vs OBS: 164 410), PTX significantly reduced fractures at any site (relative risk [RR], 0.80; 95% CI, 0.74-0.86) compared to OBS. In 237 217 patients (PTX: 73 458 vs OBS: 163 759), the risk of hip fractures decreased (RR, 0.63; 95% CI, 0.52-0.76). No reduction in forearm and vertebral fractures was observed in 3574 and 3795 patients, respectively. The annual percentage BMD changes from baseline were higher in the PTX group: femoral neck, 1.91% (95% CI, 1.14-2.68); hip, 1.75% (95% CI, 0.58-2.92); radius, 1.75% (95% CI, 0.31-3.18); spine, 2.13% (95% CI, 1.16-3.10).

CONCLUSION

PTX significantly reduced overall and hip fracture risks in PHPT patients. Despite minimal BMD increase, the substantial decrease in fracture risk suggests additional benefits of PTX beyond mineral content enhancement.

[Primary hyperparathyroidism: From diagnosis to treatment]

Primary hyperparathyroidism (PHPT) is the leading cause of hypercalcemia. It is secondary to hypersecretion of parathyroid hormone (PTH) by the parathyroid glands. Today, PHTP is asymptomatic in 80-90% of cases. Its repercussions are mainly renal (nephrolithiasis, nephrocalcinosis, decline in renal function) and skeletal (osteoporosis, fractures), and should be systematically investigated. Diagnosis is only biological, and in its classic form relies on the association of hypercalcemia, inappropriate PTH (normal or elevated) and hypercalciuria. Diagnosis of normocalcemic forms, where only PTH is elevated, requires elimination of secondary hyperparathyroidism and confirmation of elevated PTH on two consecutive samples, over a 3 to 6 months period. Imaging evaluation, which combines neck ultrasound with scintigraphy or 18F-choline PET/CT, is of interest only if surgery is indicated. Surgical management of the hyperfunctioning parathyroid gland(s) is the only curative treatment for HPTP. Medical management concerns patients for whom surgery is not indicated, who present a surgical contraindication or who refuse surgery. The diagnosis of HPTP warrants contact with an endocrinologist to ensure its management.

No effect of surgery on kidney and cardiovascular risk factors in mild primary hyperparathyroidism: secondary analyses from a 10-year randomized controlled trial

OBJECTIVE

Renal function and the skeleton are classic target organs in primary hyperparathyroidism (PHPT), affected by the chronic course of the disease. Most patients diagnosed today exhibit mild PHPT, characterized by slight hypercalcemia and no or unspecific symptoms. Concerns have been raised that PHPT could promote deteriorating kidney function and increase cardiovascular risk directly. To examine the effect of parathyroidectomy (PTX) on mild PHPT on renal function and markers for bone turnover, cardiovascular disease (CVD), and vascular inflammation.

DESIGN

Prospective randomized controlled trial. ClinicalTrials.gov: NCT00522028.

SETTING

Eight Scandinavian referral centers.

PARTICIPANTS

From 1998 to 2005, 191 patients with mild PHPT were included in Sweden, Norway, and Denmark. Of these 150 were included in the present analyses.

INTERVENTION

Seventy patients were randomized to PTX and 80 to observation without intervention (OBS).

MEASURES

e-GFR was calculated based on creatinine and cystatin C. Markers of CVD and systemic inflammation: osteoprotegerin, vascular cell adhesion molecule 1, soluble CD40 ligand, interleukin-1 receptor antagonist, von Willebrand factor. Bone turnover markers: C-terminal telopeptide of type 1 collagen (CTX-1) and serum Procollagen type 1 N-terminal propeptide.

RESULTS

No differences in the development of renal function or vascular and systemic inflammation were detected. CTX-1 was lower in PTX after 10 years.

LIMITATIONS

Secondary analyses of a randomized controlled trial.

CONCLUSION

PTX does not appear to affect renal function or markers of CVD and vascular inflammation in mild PHPT in a ten-year perspective.

Patients with prediabetes improve insulin resistance after surgery for primary hyperparathyroidism

BACKGROUND

The objective of this study was to evaluate the evolution of insulin resistance at 12 months after parathyroidectomy for primary hyperparathyroidism according to the preoperative severity of glucose metabolism abnormalities.

METHODS

Observational study of patients who underwent parathyroidectomy between 2016 and 2021. Prediabetes and insulin resistance were defined as fasting glucose ≥1.00 g/L (American Diabetes Association) and homeostatic model assessment of insulin resistance >2.5, respectively.

RESULTS

A total of 231 patients were included. Preoperatively, 75 patients (32%) had prediabetes, and 108 patients (47%) had insulin resistance. At 12 months postoperative, homeostatic model assessment of insulin resistance values significantly decreased in patients with prediabetes (-0.69; P = .04) and in patients with insulin resistance (-0.85; P < .001). In patients with prediabetes, 48/75 (64%) decreased their insulin resistance, including 15/48 (31%) with normalization of fasting glucose. In multivariate analysis, preoperative prediabetes (1.82, 1.03-3.21; P = .037) or preoperative homeostatic model assessment of insulin resistance >2.5 (3.90, 2.23-6.75; P < .001) remained independent predictors for insulin resistance reduction observed between preoperative and 12 months postoperative.

CONCLUSION

Parathyroidectomy is more likely to reduce insulin resistance in patients with primary hyperparathyroidism and prediabetes or in patients with higher preoperative homeostatic model assessment of insulin resistance values. These data support the use of the preoperative prediabetes criterion in addition to the international workshop criteria for parathyroidectomy to better select patients for surgery.

Biochemical markers and FokI and TaqI vitamin D receptor genes polymorphism in rheumatoid arthritis

BACKGROUND

Previous studies have reported the role of genes in different metabolic processes in the human body, and any variation in gene polymorphisms could lead to disturbances in these processes and different diseases.

OBJECTIVE

This study aimed to compare vitamin D receptor (VDR) FokI and TaqI genotypes in terms of parathyroid hormone (PTH) and some biomarkers of inflammation and susceptibility to rheumatoid arthritis (RA) disease.

METHODS

This study included 100 patients with rheumatoid arthritis (RA). Genotyping was performed by polymerase chain reaction (PCR) and examined by specific restriction enzymes using restriction fragment length polymorphism (RFLP). Serum intact PTH, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), and anti-cyclic citrullinated peptide antibodies (ACCPs) levels were measured.

RESULTS

An increased PTH level (> 65 pg/ml) was found in 8% of patients. No significant differences among FokI and TaqI vitamin D receptor genes polymorphism regarding positive and negative RF or ACCPs were found. A significant difference was found among FokI (p = 0.009) and none in TaqI genotypes regarding intact parathyroid hormone level categories. No significant correlation was found between the serum intact PTH level and ESR or CRP levels (P = 0.13 and 0.28, respectively). The parathyroid hormone level was not a good predictor for RF or ACCPs (P = 0.5 and 0.06, respectively).

CONCLUSION

The FokI gene may play a role in controlling PTH levels in patients with RA. There was no significant correlation found between the serum intact PTH level and RA severity according to ESR and CRP inflammatory biomarkers. There are no differences between VDR genes FokI and TaqI polymorphism in terms of RA susceptibility (for RF and ACCPs).

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Improvement of hypertension control and left-ventricular function after cure of primary hyperparathyroidism

Introduction

Cardiovascular mortality is significantly higher in patients with primary hyperparathyroidism (PHPT) compared to the general population. The role of the renin-angiotensin-aldosterone system (RAAS) as a mediator of cardiovascular pathology in PHPT is unclear, as is the question whether successful parathyroidectomy (PTX) mitigates hypertension (HT), and left-ventricular (LV) dysfunction.

Methods

In 45 consecutive, hypercalcemic PHPT patients (91% female, 20 normotensive, mean age 54.6 ± 14.6), laboratory examinations, and 24 h ambulatory blood pressure monitoring (ABPM) were performed before, one and six months after successful PTX, while transthoracic echocardiography (TTE) pre- and six months post-PTX.

Results

Both in patients with normotension (NT) and HT, lower calcemia and parathyroid hormone (PTH) as well as higher phosphatemia were observed on follow-up, while B-type natriuretic peptide, aldosterone, plasma renin activity, and aldosterone-to-renin ratios were comparable. Six months post-PTX, only in patients with HT, median 24-hour SBP/DBP decreased by 12/6 mmHg, daytime SBP by 10, and nighttime DBP by 5 mmHg. Improvement in BP was observed in approximately 78% of patients with HT. Six months post-PTX, TTE revealed: 1) decrease in median LV mass index (by 2 g/m2) and end-diastolic dimension (by 3 mm) among patients with HT; 2) normalization of global longitudinal strain in 22% of patients (comparable between those with NT and HT); 3) a mean 12.7% reduction in left-atrium volume index among patients with HT, which underlay normalization of indeterminate diastolic function in 3 out of 6 patients with HT, who exhibited it at baseline (dysfunction persisted in 2).

Conclusions

PTX was shown to significantly reduce BP, LV hypertrophy and diastolic dysfunction parameters in PHPT patients with HT, and improve systolic function in all PHPT patients.

Parathyroidectomy for adults with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT), a disorder in which the parathyroid glands produce excessive amounts of parathyroid hormone, is most common in older adults and postmenopausal women. While most people with PHPT are asymptomatic at diagnosis, symptomatic disease can lead to hypercalcaemia, osteoporosis, renal stones, cardiovascular abnormalities and reduced quality of life. Surgical removal of abnormal parathyroid tissue (parathyroidectomy) is the only established treatment for adults with symptomatic PHPT to prevent exacerbation of symptoms and to be cured of PHPT. However, the benefits and risks of parathyroidectomy compared to simple observation or medical therapy for asymptomatic and mild PHPT are not well established.

OBJECTIVES

To evaluate the benefits and harms of parathyroidectomy in adults with PHPT compared to simple observation or medical therapy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, LILACS, ClinicalTrials.gov and WHO ICTRP from their date of inception until 26 November 2021. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing parathyroidectomy with simple observation or medical therapy for the treatment of adults with PHPT.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. cure of PHPT, 2. morbidity related to PHPT and 3. serious adverse events. Our secondary outcomes were 1. all-cause mortality, 2. health-related quality of life and 3. hospitalisation for hypercalcaemia, acute renal impairment or pancreatitis. We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We identified eight eligible RCTs that included 447 adults with (mostly asymptomatic) PHPT; 223 participants were randomised to parathyroidectomy. Follow-up duration varied from six months to 24 months. Of the 223 participants (37 men) randomised to surgery, 164 were included in the analyses, of whom 163 were cured at six to 24 months (overall cure rate 99%). Parathyroidectomy compared to observation probably results in a large increase in cure rate at six to 24 months follow-up: 163/164 participants (99.4%) in the parathyroidectomy group and 0/169 participants in the observation or medical therapy group were cured of their PHPT (8 studies, 333 participants; moderate certainty).  No studies explicitly reported intervention effects on morbidities related to PHPT, such as osteoporosis, osteopenia, kidney dysfunction, urolithiasis, cognitive dysfunction or cardiovascular disease, although some studies reported surrogate outcomes for osteoporosis and cardiovascular disease. A post-hoc analysis revealed that parathyroidectomy, compared to observation or medical therapy, may have little or no effect after one to two years on bone mineral density (BMD) at the lumbar spine (mean difference (MD) 0.03 g/cm2,95% CI -0.05 to 0.12; 5 studies, 287 participants; very low certainty). Similarly, compared to observation, parathyroidectomy may have little or no effect on femoral neck BMD after one to two years (MD -0.01 g/cm2, 95% CI -0.13 to 0.11; 3 studies, 216 participants; very low certainty). However, the evidence is very uncertain for both BMD outcomes. Furthermore, the evidence is very uncertain about the effect of parathyroidectomy on improving left ventricular ejection fraction (MD -2.38%, 95% CI -4.77 to 0.01; 3 studies, 121 participants; very low certainty). Four studies reported serious adverse events. Three of these reported zero events in both the intervention and control groups; consequently, we were unable to include data from these three studies in the pooled analysis. The evidence suggests that parathyroidectomy compared to observation may have little or no effect on serious adverse events (RR 3.35, 95% CI 0.14 to 78.60; 4 studies, 168 participants; low certainty).  Only two studies reported all-cause mortality. One study could not be included in the pooled analysis as zero events were observed in both the intervention and control groups. Parathyroidectomy compared to observation may have little or no effect on all-cause mortality, but the evidence is very uncertain (RR 2.11, 95% CI 0.20 to 22.60; 2 studies, 133 participants; very low certainty). Three studies measured health-related quality of life using the 36-Item Short Form Health Survey (SF-36) and reported inconsistent differences in scores for different domains of the questionnaire between parathyroidectomy and observation. Six studies reported hospitalisations for the correction of hypercalcaemia. Two studies reported zero events in both the intervention and control groups and could not be included in the pooled analysis. Parathyroidectomy, compared to observation, may have little or no effect on hospitalisation for hypercalcaemia (RR 0.91, 95% CI 0.20 to 4.25; 6 studies, 287 participants; low certainty). There were no reported hospitalisations for renal impairment or pancreatitis.

AUTHORS' CONCLUSIONS

In accordance with the literature, our review findings suggest that parathyroidectomy, compared to simple observation or medical (etidronate) therapy, probably results in a large increase in cure rates of PHPT (with normalisation of serum calcium and parathyroid hormone levels to laboratory reference values). Parathyroidectomy, compared with observation, may have little or no effect on serious adverse events or hospitalisation for hypercalcaemia, and the evidence is very uncertain about the effect of parathyroidectomy on other short-term outcomes, such as BMD, all-cause mortality and quality of life. The high uncertainty of evidence limits the applicability of our findings to clinical practice; indeed, this systematic review provides no new insights with regard to treatment decisions for people with (asymptomatic) PHPT. In addition, the methodological limitations of the included studies, and the characteristics of the study populations (mainly comprising white women with asymptomatic PHPT), warrant caution when extrapolating the results to other populations with PHPT. Large-scale multi-national, multi-ethnic and long-term RCTs are needed to explore the potential short- and long-term benefits of parathyroidectomy compared to non-surgical treatment options with regard to osteoporosis or osteopenia, urolithiasis, hospitalisation for acute kidney injury, cardiovascular disease and quality of life.

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).

Mortality and Morbidity in Mild Primary Hyperparathyroidism: Results From a 10-Year Prospective Randomized Controlled Trial of Parathyroidectomy Versus Observation

BACKGROUND

Primary hyperparathyroidism (PHPT) is a common endocrine disorder associated with increased risk for fractures, cardiovascular disease, kidney disease, and cancer and increased mortality. In mild PHPT with modest hypercalcemia and without known morbidities, parathyroidectomy (PTX) is debated because no long-term randomized trials have been performed.

OBJECTIVE

To examine the effect of PTX on mild PHPT with regard to mortality (primary end point) and key morbidities (secondary end point).

DESIGN

Prospective randomized controlled trial. (ClinicalTrials.gov: NCT00522028).

SETTING

Eight Scandinavian referral centers.

PATIENTS

From 1998 to 2005, 191 patients with mild PHPT were included.

INTERVENTION

Ninety-five patients were randomly assigned to PTX, and 96 were assigned to observation without intervention (OBS).

MEASUREMENTS

Date and causes of death were obtained from the Swedish and Norwegian Cause of Death Registries 10 years after randomization and after an extended observation period lasting until 2018. Morbidity events were prospectively registered annually.

RESULTS

After 10 years, 15 patients had died (8 in the PTX group and 7 in the OBS group). Within the extended observation period, 44 deaths occurred, which were evenly distributed between groups (24 in the PTX group and 20 in the OBS group). A total of 101 morbidity events (cardiovascular events, cerebrovascular events, cancer, peripheral fractures, and renal stones) were also similarly distributed between groups (52 in the PTX group and 49 in the OBS group). During the study, a total of 16 vertebral fractures occurred in 14 patients (7 in each group).

LIMITATION

During the study period, 23 patients in the PTX group and 27 in the OBS group withdrew.

CONCLUSION

Parathyroidectomy does not appear to reduce morbidity or mortality in mild PHPT. Thus, no evidence of adverse effects of observation was seen for at least a decade with respect to mortality, fractures, cancer, cardiovascular and cerebrovascular events, or renal morbidities.

PRIMARY FUNDING SOURCE

Swedish government, Norwegian Research Council, and South-Eastern Norway Regional Health Authority.

Analysis of Comorbidities, Clinical Outcomes, and Parathyroidectomy in Adults With Primary Hyperparathyroidism

Importance

Patients with primary hyperparathyroidism (pHPT) appear to have an increased risk of fractures and other comorbidities, such as cardiovascular disease, although results from previous studies have been inconsistent. Evidence of the association of parathyroidectomy (PTX) with these outcomes is also limited because of the lack of large well-controlled trials.

Objective

To investigate whether untreated pHPT was associated with an increased risk of incident fractures and cardiovascular events (CVEs) and whether PTX was associated with a reduced risk of these outcomes.

Design, Setting, and Participants

This cohort study included all patients who were diagnosed with pHPT at hospitals in Sweden between July 1, 2006, and December 31, 2017. Each patient was matched with 10 control individuals from the general population by sex, birth year, and county of residence. The patients were followed up until December 31, 2017. Data analyses were performed from October 2021 to April 2022.

Main Outcomes and Measures

The primary outcomes were fractures, CVEs, and death. Cumulative incidence of events was estimated using the 1-minus Kaplan-Meier estimator of corresponding survival function. Cox proportional hazards regression models were used to calculate hazard ratios (HRs).

Results

A total of 16 374 patients with pHPT were identified (mean [SD] age, 67.5 [12.9] years; 12 806 women [78.2%]), with 163 740 control individuals. The follow-up time was 42 310 person-years for the pHPT group and 803 522 person-years for the control group. Compared with the control group, the pHPT group had a higher risk of any fracture (unadjusted HR, 1.39; 95% CI, 1.31-1.48), hip fracture (unadjusted HR, 1.51; 95% CI, 1.35-1.70), CVEs (unadjusted HR, 1.45; 95% CI, 1.34-1.57), and death (unadjusted HR, 1.72; 95% CI, 1.65-1.80). In a time-dependent Poisson regression model, PTX was associated with a reduced risk of any fracture (HR, 0.83; 95% CI, 0.75-0.93), hip fracture (HR, 0.78; 95% CI, 0.61-0.98), CVEs (HR, 0.84; 95% CI, 0.73-0.97), and death (HR, 0.59; 95% CI, 0.53-0.65).

Conclusions and Relevance

Results of this study suggest that pHPT is associated with increased risk of fractures, CVEs, and death, highlighting the importance of identifying patients with this condition to prevent serious unfavorable outcomes. The reduced risk of these outcomes associated with PTX suggests a clinical benefit of surgery.

Effect of Parathyroidectomy on Metabolic Homeostasis in Primary Hyperparathyroidism

Background: The benefits of parathyroidectomy on cardiovascular risk in primary hyperparathyroidism (PHPT) are controversial. This monocentric, observational, prospective study aimed to assess the effects of parathyroidectomy on glucose and lipid metabolism in classic or mild PHPT. Methods: Patients who underwent parathyroidectomy for classic (calcemia >2.85 mmol/L) or mild PHPT (calcemia ≤2.85 mmol/L) between 2016 and 2019 were included. A metabolic assessment was performed before and 1 year after parathyroidectomy. Patients with a history of diabetes were excluded. Results: Nineteen patients had classic and 120 had mild PHPT. Ninety-five percent were normocalcemic 6 months after surgery. Fasting plasma glucose and insulin levels decreased after parathyroidectomy in patients with mild PHPT (p < 0.001). HOMA-IR decreased after surgery in the overall population (p < 0.001), while plasma adiponectin concentrations increased in patients with both classic (p = 0.005) and mild PHPT (p < 0.001). Plasma triglyceride levels decreased significantly only in patients with classic PHPT (p = 0.021). Plasma PCSK9 levels decreased in patients with mild PHPT (p < 0.001). Conclusions: Parathyroidectomy for PHPT improves insulin resistance and decreases plasma triglyceride levels in classic PHPT and plasma PCSK9 levels in mild PHPT. Further studies are needed to better characterize the consequences of such metabolic risk factors’ improvements on cardiovascular events.

Impact of curative parathyroidectomy on left ventricular functions assessed with 2D ECHO and MUGA study

Objective: Primary hyperparathyroidism (PHPT) is associated with increased cardiovascular morbidity and mortality with inconsistent results on the reversibility of cardiovascular changes after parathyroidectomy (PTx). The present study was undertaken to evaluate both structural and functional cardiac changes and their reversal after PTx in patients with PHPT.

Material and Methods: Thirty patients of symptomatic PHPT without cardiovascular risk factors were evaluated prospectively by means of 2D echocar- diography (ECHO) and Multigated Acquisition (MUGA) study before surgery and six months after curative parahyroidectomy.

Results: Nine of 30 patients had hypertension which improved in two after PTx (p 0.20). Two patients had left ventricle hypertrophy on 2D ECHO pre- operatively which improved after PTx (p< 0.001). Left ventricular ejection fraction (LVEF) did not show significant change before and after PTx on 2D ECHO. Nine out of 30 patients had hypertension which improved in two after PTx (p 0.20). Two patients with left ventricle hypertrophy on 2D ECHO preoperatively improved after PTx (p< 0.001). Left ventricular ejection fraction (EF) did not depict significant change before and after PTx on 2D ECHO. Whereas, four out of six patients with preoperative EF <50% representing systolic dysfunction on MUGA study showed improvement after PTx. On 2D ECHO, eight patients depicted diastolic dysfunction which improved in six patients after curative surgery (p= 0.07). However, on MUGA study, 13 pa- tients presented with tTPF >180 ms indicating diastolic dysfunction, of which ten showed improvement after PTx (p= 0.007).

Conclusion: The present study analyzed preoperative and postoperative cardiac function using both 2D ECHO and MUGA study. MUGA study provided a more objective assessment of the cardiac function by determining left ventricular ejection fraction and diastolic dysfunction.

Nontraditional Aspects of Sporadic Primary Hyperparathyroidism

Nontraditional aspects of primary hyperparathyroidism refer to the condition's rheumatic, gastrointestinal, cardiovascular, and neuropsychological effects. Although gastrointestinal and rheumatic symptomatology were features of classical primary hyperparathyroidism, they do not seem to be a part of the modern presentation of primary hyperparathyroidism. In contrast, neuropsychological symptoms such as altered mood and cognition, as well as cardiovascular disease, have been associated with the form of primary hyperparathyroidism seen today, but the relationship is not clearly causal. Evidence does not support reversibility after parathyroidectomy and therefore none of the nontraditional manifestations are considered sole indications for recommending surgery at this time.

Assessment of insulin resistance in patients with primary hyperparathyroidism before and after Parathyroidectomy

Background

Primary hyperparathyroidism (PHPT) can lead to renal and skeletal disorders, as well as insulin resistance and impaired glucose metabolism. The current study aimed to assess the effects of parathyroidectomy on insulin resistance in patients with PHPT.

Materials and Methods

The present study was conducted on 65 patients with PHPT and indications for parathyroidectomy who were referred to the endocrinology clinics of Mashhad University of Medical Sciences. Thereafter, the demographic characteristics of the patients were recorded. Blood tests, including haemoglobin A1c (HbA1c), fasting blood glucose (FBG) and insulin levels, were assessed one week before and three months after the surgery. The insulin resistance score (HOMA‐IR) was calculated and compared using the relevant formula.

Results

A total of 65 participants with a mean age of 45.44 ± 9.59 years were included in the current study. In one‐month postoperative tests, mean scores of FBG (p < .05), insulin level (p < .05) and HbA1c (p < .05) were significantly reduced. Moreover, the HOMA‐IR index decreased in 51 patients after the surgery.

Conclusion

According to our findings, parathyroidectomy can be effective in the reduction of insulin resistance and corresponding complications in patients with PHPT in the present short‐term study. However, it has yet to be confirmed as a treatment method for insulin resistance in these patients. Future long‐term studies are required to be done to investigate the effect of parathyroidectomy on insulin resistance.

The present study aimed to assess the effects of parathyroidectomy on insulin resistance in patients with primary hyperparathyroidism (PHPT). The present study was conducted on 65 patients with PHPT and indications for parathyroidectomy. Demographic characteristics of the patients were recorded. Blood tests, including fasting blood sugar (FBS), haemoglobin A1c (HbA1c) and insulin levels, were assessed one week before and three months after the surgery. The Homeostatic Model Assessment for Insulin Resistance (HOMA‐IR index) was calculated. In one‐month postoperative tests, mean scores of FBS (p < .05), insulin level (p < .05) and HbA1c (p < 0.05) were significantly reduced compared to these variables prior to the surgery. Moreover, the HOMA‐IR index decreased in 51 patients after the surgery. As evidenced by the results of the present study, parathyroidectomy can be effective in reducing insulin resistance and its complications in patients with primary hyperparathyroidism (PHPT).

The Association Between Dietary Inflammatory Index and Parathyroid Hormone in Adults With/Without Chronic Kidney Disease

Aims: We aimed to assess the association between dietary inflammation index (DII) with parathyroid hormone (PTH) and hyperparathyroidism (HP) in adults with/without chronic kidney disease (CKD).

Methods: Data were obtained from the 2003–2006 National Health and Nutrition Examination Survey (NHANES). The participants who were <18 years old, pregnant, or missing the data of DII, PTH, and CKD were excluded. DII was calculated based on a 24-h dietary recall interview for each participant. Weighted multivariable regression analysis and subgroup analysis were conducted to estimate the independent relationship between DII with PTH and the HP in the population with CKD/non-CKD.

Results: A total of 7,679 participants were included with the median DII of −0.24 (−2.20 to 1.80) and a mean PTH level of 43.42 ± 23.21 pg/ml. The average PTH was 45.53 ± 26.63 pg/ml for the participants in the highest tertile group compared with 41.42 ± 19.74 pg/ml in the lowest tertile group (P < 0.0001). The rate of HP was 11.15% overall, while the rate in the highest DII tertile was 13.28 and 8.60% in the lowest DII tertile (P < 0.0001). The participants with CKD tended to have higher PTH levels compared with their counterparts (61.23 ± 45.62 vs. 41.80 ± 19.16 pg/ml, P < 0.0001). A positive association between DII scores and PTH was observed (β = 0.46, 95% CI: 0.25, 0.66, P ≤ 0.0001), and higher DII was associated with an increased risk of HP (OR = 1.05, 95% CI: 1.02, 1.08, P = 0.0023). The results from subgroup analysis indicated that this association was similar in the participants with different renal function, gender, age, BMI, hypertension, and diabetes statuses and could also be appropriate for the population with CKD.

Conclusions: Higher consumption of a pro-inflammatory diet appeared to cause a higher PTH level and an increased risk of HP. Anti-inflammatory dietary management may be beneficial to reduce the risk of HP both in the population with and without CKD.

Meta-analysis on the Effect of Mild Primary Hyperparathyroidism and Parathyroidectomy Upon Arterial Stiffness

CONTEXT

Current data about the cardiovascular manifestations of mild primary hyperparathyroidism (pHPT) are often conflicting. Pulse wave velocity (PWV) is the gold standard for assessing aortic stiffness, and it predicts cardiovascular morbidity and mortality.

OBJECTIVE

Primary outcomes were to investigate if mild pHPT was associated with higher PWV and if parathyroidectomy (PTX) reduced PWV in mild pHPT. Secondary outcome was to investigate blood pressure changes after PTX.

METHODS

Sources were PubMed, Google Scholar, SCOPUS, Web of Science, and the Cochrane Library. Eligible studies included reports of PWV in patients with mild pHPT and controls, or in patients with mild pHPT before and after PTX. Two investigators independently identified eligible studies and extracted data. Pooled mean difference (MD) was the summary effect measure. Data were presented in forest plots with outlier and influential case diagnostics. Nine observational studies and one randomized clinical trial were selected, including 433 patients with mild pHPT, 171 of whom underwent PTX, and 407 controls. PWV was significantly higher in mild pHPT than in controls (MD = 1.18, 0.67 to 1.68, P < .0001). Seven studies evaluated the effect of PTX on PWV. PTX significantly reduced PWV (MD = -0.48, -0.88 to -0.07, P = .022).

CONCLUSION

Aortic stiffness is increased in patients with mild pHPT, supporting the notion that mild pHPT is also associated with adverse cardiovascular manifestations. PTX significantly reduced arterial stiffness in mild pHPT, indicating that the benefit of PTX over cardiovascular manifestations should not be dismissed but it deserves further studies.

Cardiovascular Risk in Patients with Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is one of the most common endocrine disorders characterized by parathyroid hormone (PTH)-dependent hypercalcemia. Cardinal features include low trauma fractures, nephrolithiasis, and chronic kidney disease. Several experimental studies established that parathyroid hormone exerts actions on the cardiovascular (CV) system, including vasodilatation and positive inotropic and chronotropic effects. Observational studies, especially in severe cases, report a higher prevalence of hypertension, diabetes mellitus, lipid abnormalities, endothelial dysfunction, arrhythmias, and left ventricular hypertrophy in patients with PHPT, while the risk of CV events seems to be increased in severe cases. However, the effect of surgery is inconsistent on CV abnormalities and, more importantly, on CV disease (CVD) events, especially in mild cases. In the current review, we describe the available evidence linking PHPT and CVD, as well as the effect of surgical management and pharmacological treatment on CVD manifestations in patients with PHPT. Based on the current evidence, CVD is not considered an indication for surgery.

Impact of parathyroidectomy on cardiovascular risk in primary hyperparathyroidism: A narrative review

AIMS

Primary hyperparathyroidism (PHPT), one of the most frequent endocrine disorders, is not only associated with bone and kidney disorders but also with increased cardiovascular risk. This cardiovascular risk is not part of the indication for surgery owing to discordant evidence of the effects of parathyroidectomy (PTX), especially in mild PHPT which is the most common presentation of PHPT. This literature review focuses on the effects of PTX on the cardiovascular risk in PHPT. The MEDLINE database was searched via the PubMed interface, selecting relevant articles published after 1990 in English.

DATA SYNTHESIS

In the most recent series, PTX appeared to have a positive impact on cardiovascular morbidity and mortality. Surgery improves arterial hypertension, markers of glucose homeostasis, vascular and cardiac remodeling and electrocardiographic impairments due to classical PHPT. However, the results of surgery on mild PHPT are conflicting.

CONCLUSIONS

PTX seems to improve cardiovascular risk in patients presenting the classical form of PHPT. This improvement is correlated with preoperative serum calcium and/or PTH level, depending on the cardiovascular risk factor. However, many aspects of this improvement are not fully understood. Future studies should assess the effects of PTX on nocturnal hypertension, cardiac morphology and functions. The results for mild PHPT are conflicting owing to the limited size of the cohorts included in studies and the lack of randomized trials. Surgery is not currently recommended for patients presenting mild PHPT based on the cardiovascular risk and more studies are needed to better understand the interest of PTX on cardiovascular outcomes.

The influence of parathyroidectomy on cardiometabolic risk factors in patients with primary hyperparathyroidism: a systematic review and meta-analysis

PURPOSE

Primary hyperparathyroidism (PHPT) is associated with increased risk of cardiovascular morbidity and mortality. We aim to determine whether parathyroidectomy (PTX) can change cardiometabolic risk factors including serum lipids, glycemic parameters, systolic and diastolic blood pressure, C reactive protein (CRP), and body mass index (BMI).

METHODS

MEDLINE, Web of Science, Scopus, and Google Scholar were searched for relevant articles published till June 2020. Fixed-effect or random-effects models were used to estimate the weighted mean difference (WMD) and 95% CI for outcomes where applicable.

RESULTS

In total, 34 studies were eligible to be included in the current meta-analysis. Our results indicated no favorable change in serum triglyceride (n = 13, WMD = -0.06, 95% CI: -0.15, 0.03 mmol/L), total cholesterol (n = 15, WMD = 0.01, 95% CI: -0.14, 0.16 mmol/L), LDL-C (n = 10, WMD = -0.01, 95% CI: -0.17, 0.19 mmol/L), HDL-C (n = 10, WMD = 0.03, 95% CI: -0.001, 0.06 mmol/L), and CRP (n = 5, WMD = 0.82, 95% CI: -0.01, 1.64 mg/L) after PTX in PHPT patients. However, glucose (n = 24, WMD = -0.16, 95% CI: -0.26, -0.06 mmol/L), serum insulin (n = 12, WMD = -1.11, 95% CI: -1.73, -0.49 µIU/mL), systolic (n = 17, WMD = -10.14, 95% CI: -12.27, -8.01 mmHg), and diastolic (n = 16, WMD = -5.21, 95% CI: -7.0, -3.43 mmHg) blood pressures were decreased after PTX, whilst a significant increase was observed in BMI (n = 13, WMD = 0.35, 95% CI: 0.19, 0.51 kg/m²).

CONCLUSIONS

PTX could improve glycemic parameters and blood pressure, without any significant change in serum lipoproteins and CRP.

Cardiovascular consequences of parathyroid disorders in adults

PTH is a metabolic active hormone primarily regulating calcium and phosphate homeostasis in a very tight and short term-manner. Parathyroid disorders in adult patients reflect a variety of different conditions related either to the parathyroid glands itself or to the effects of the secreted hormone. The clinical spectrum varies from the common disease primary hyperparathyroidism (PHPT) to the orphan conditions pseudohypoparathyroidism (Ps-HypoPT) and chronic hypoparathyroidism (HypoPT). The purpose of this review is to describe the consequences of disturbances in levels or action of PTH for cardiac function and cardiovascular risk in adult patients with these disorders. Most patients with PHPT achieve the diagnose by chance and have minor or no specific symptoms. Still, these patients with mild PHPT do possess cardiovascular (CV) morbidity, however so far not proven ameliorated by surgery in controlled trials. In severe cases, the CV risk is increased and with a potential reversibility by treatment. Patients with Ps-HypoPT have resistance to PTH action, but not necessarily total resistance in all tissues. So far, no clear CV morbidity or risk has been demonstrated, but there are several aspects of interest for further studies. Most patients with HypoPT do get their hormonal deficiency syndrome following neck surgery. These patients do experience multiple symptoms and do have an increased CV-risk before the primary surgery. Based on existing data, their CV mortality do not deviate from the expected when adjusting for the preexisting increased risk. Patients with nonsurgical (NS-) HypoPT do demonstrate increased CV-risk also associated with exposure time. Endocrine disorders with alterations in PTH function have major impact on the cardiovascular system of importance for morbidity and mortality, wherefore management of these specific diseases should be optimized currently, as new data become available, however also avoiding over-treating asymptomatic patients.

Primary hyperparathyroidism and hypertension

Although untreated primary hyperparathyroidism is associated with increased cardiovascular mortality, controversy exists regarding the therapeutic effects of parathyroidectomy on cardiovascular health. This review will examine the evidence linking primary hyperparathyroidism (PHPT) and cardiovascular disease, specifically hypertension, and evaluate the available literature regarding the natural history of hypertension after successful parathyroidectomy.

The role of parathyroidectomy in treating hypertension and other cardiac manifestations of primary hyperparathyroidism

Among many recognized sequelae of primary hyperparathyroidism (PHPT), cardiovascular disease remains incompletely understood as a consequence of disordered calcium and parathyroid hormone (PTH) metabolism. While population studies have identified trends that associate PHPT with hypertension, metabolic syndrome, and vascular system calcifications, the fundamental pathophysiology, natural history, and opportunity to reverse or cure the cardiovascular effects with parathyroidectomy are not well established. This chapter reviews the current knowledge of this field of interest within PHPT and summarizes key findings from dedicated investigations that have addressed the impact of parathyroid surgery on the cardiovascular system.

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

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

Serum Parathyroid Hormone and Risk of Coronary Artery Disease: Exploring Causality Using Mendelian Randomization

CONTEXT

Elevated circulating parathyroid hormone concentrations have been associated with increased risk of cardiovascular disease in observational studies, but whether the association is causal is unknown.

OBJECTIVE

We used the Mendelian randomization design to test whether genetically increased serum parathyroid hormone (S-PTH) concentrations are associated with coronary artery disease (CAD).

DESIGN, SETTING, AND PARTICIPANTS

Five single-nucleotide polymorphisms robustly associated with S-PTH concentrations were used as instrumental variables to estimate the association of genetically higher S-PTH concentrations with CAD. Summary statistics data for CAD were obtained from a genetic consortium with data from 184,305 individuals (60,801 CAD cases and 123,504 noncases).

MAIN OUTCOME MEASURE

OR of CAD per genetically predicted one SD increase of S-PTH concentrations.

RESULTS

Genetically higher S-PTH concentration was not associated with CAD as a whole or myocardial infarction specifically (∼70% of total cases). The ORs per genetically predicted one SD increase in S-PTH concentration were 1.01 (95% CI: 0.93 to 1.09; P = 0.88) for CAD and 1.02 (95% CI: 0.94 to 1.10; P = 0.64) for myocardial infarction. The lack of association remained in various sensitivity analyses.

CONCLUSION

Genetic predisposition to higher S-PTH concentrations does not appear to be an independent risk factor for CAD.

MANAGEMENT OF ENDOCRINE DISEASE: Unmet therapeutic, educational and scientific needs in parathyroid disorders

PARAT, a new European Society of Endocrinology program, aims to identify unmet scientific and educational needs of parathyroid disorders, such as primary hyperparathyroidism (PHPT), including parathyroid cancer (PC), and hypoparathyroidism (HypoPT). The discussions and consensus statements from the first PARAT workshop (September 2018) are reviewed. PHPT has a high prevalence in Western communities, PHPT has a high prevalence in Western communities, yet evidence is sparse concerning the natural history and whether morbidity and long-term outcomes are related to hypercalcemia or plasma PTH concentrations, or both. Cardiovascular mortality and prevalence of low energy fractures are increased, whereas Quality of Life is decreased, although their reversibility by treatment of PHPT has not been convincingly demonstrated. PC is a rare cause of PHPT, with an increasing incidence, and international collaborative studies are required to advance knowledge of the genetic mechanisms, biomarkers for disease activity, and optimal treatments. For example, ~20% of PCs demonstrate high mutational burden, and identifying targetable DNA variations, gene amplifications and gene fusions may facilitate personalized care, such as different forms of immunotherapy or targeted therapy. HypoPT, a designated orphan disease, is associated with a high risk of symptoms and complications. Most cases are secondary to neck surgery. However, there is a need to better understand the relation between disease biomarkers and intellectual function, and to establish the role of PTH in target tissues, as these may facilitate the appropriate use of PTH substitution therapy. Management of parathyroid disorders is challenging, and PARAT has highlighted the need for international transdisciplinary scientific and educational studies in advancing in this field.

Effect of Parathyroidectomy on Cardiovascular Risk Factors in Primary Hyperparathyroidism: A Randomized Clinical Trial

CONTEXT

It remains unclear whether risk of cardiovascular diseases is increased in patients with mild (<1.45 mmol/L) to moderate (≥1.45 to 1.60 mmol/L) primary hyperparathyroidism (PHPT).

OBJECTIVE

We aimed to determine the short-term effect of parathyroidectomy (PTX) on arterial stiffness, cholesterol levels, and blood pressure (BP).

DESIGN

This study was a clinical trial randomly allocating patients to either PTX or a control group (no surgery). Follow-up was performed 3 months after surgery in the PTX group and 3 months after baseline in the control group.

SETTING

University hospital.

PARTICIPANTS

We recruited 79 patients with PHPT; 69 participants completed the study.

MAIN OUTCOMES

Office and ambulatory 24-hour BP, pulse wave velocity (PWV), augmentation index, and fasting plasma cholesterol levels.

RESULTS

At baseline, participants had a median level of ionized calcium of 1.41 mmol/L (range, 1.33 to 1.60 mmol/L) and PTH of 10.4 pmol/L (4.5 to 30.4 pmol/L). Median age was 64 years (range, 18 to 81) and 72% were females. Following PTX, plasma total cholesterol levels decreased significantly compared with the controls (P = 0.04). Changes in PWV, augmentation index, and ambulatory 24-hour BP did not differ between groups, except for an increase in ambulatory diastolic BP following PTX. However, in patients with baseline levels of ionized calcium ≥1.45 mmol/L, PWV decreased significantly in response to PTX compared with the control group (P = 0.03).

CONCLUSION

PTX may decrease risk of cardiovascular diseases in PHPT by lowering total cholesterol levels, although ambulatory diastolic BP increases in response to surgery. Patients with moderate to severe hypercalcemia may benefit from PTX by a decrease in PWV.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Mild primary hyperparathyroidism-to treat or not to treat?

INTRODUCTION

The presentation of primary hyperparathyroidism (PHPT) has shifted from a disease characterized by renal and skeletal complications to a mild or asymptomatic condition. Modern imaging allows localization of a surgical target in the majority of cases.

SOURCES OF DATA

Data were collected from literature searches of online databases including PUBMED, MEDLINE and Cochrane. A narrative review was performed.

AREAS OF AGREEMENT

Parathyroidectomy is the only therapy with curative potential with good outcomes and low risk of complications in experienced hands. Current guidelines advocate that surgery is offered in all symptomatic cases and in those who meet criteria depending on age, serum calcium concentration, skeletal and renal parameters. A structured monitoring approach should be offered to those who do not undergo surgery.

AREAS OF CONTROVERSY

Thresholds for intervention to improve skeletal and renal outcomes are debatable. In addition, controversy persists over the benefit of surgery for non-skeletal/renal outcomes.

GROWING POINTS

The role of medical management of PHPT using agents such as bisphosphonates, denosumab and cinacalcet are discussed.

AREAS TIMELY FOR DEVELOPING RESEARCH

In summary, further data on the natural history and effects of treatment of mild and asymptomatic PHPT are required to determine thresholds for surgery. In particular, further investigations of non-skeletal and non-renal parameters, such as neurocognitive quality of life and cardiovascular disease are required. Data on normocalcaemic PHPT are lacking. Large-scale randomized controlled trials would be welcome in these areas, however in view of the cost implications a more pragmatic approach may be to develop collaborative multi-centre registries.

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

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

Bone mineral density evolution and incidence of fractures in a cohort of patients with primary hyperparathyroidism treated with parathyroid surgery vs active surveillance during 6 years of follow-up

INTRODUCTION

The need for parathyroidectomy to treat asymptomatic patients with primary hyperparathyroidism is controversial. The aim of this study was to assess the impact of parathyroidectomy vs. surveillance on skeletal outcomes such as bone mineral density (BMD) and incident fractures.

METHODS

This was a retrospective cohort study including 170 patients (112 treated with surgery and 58 subject to active surveillance) between 1991 and 2014. Changes in BMD in lumbar spine, femoral neck, total hip, and radius, and incidence of fractures, were monitored for 2-6 years.

RESULTS

Patients treated with surgery had BMD gains at 2years of 4.37%, as compared to 1.59% in non-operated patients (p<0.05) in the lumbar spine, 3.90% vs. 0.19% (p<0.05) in the femoral neck, and 2.70% vs. 0.14% (p<0.05) in total hip. Gain in BMD in the lumbar spine and femoral neck remained significant in operated patients at 4 and 6 years. No improvement was seen in the radius in operated patients. No significant difference was seen in fracture occurrence between operated and non-operated patients.

CONCLUSION

Patients with primary hyperparathyroidism treated with surgery experience greater BMD gains than non-operated patients, especially in the lumbar spine and femoral neck. The risk of fracture does not decrease in the group of operated patients.

Non classical complications of primary hyperparathyroidism

Several studies suggested that the condition of primary hyperparathyroidism (PHPT) may be associated not only with the classical bone, kidney and gastrointestinal consequences, but also with cardiovascular, neuromuscular and articular complications, impaired quality of life and increased cancer risk. However, the only cardiovascular complications associated with PHPT, which seems to improve after parathyroidectomy, is left ventricular hypertrophy, while, data regarding the reversibility of hypertension, valve calcifications and increased vascular stiffness are inconsistent. Parathyroidectomy seems to ameliorate neuropsychological, cognitive disturbances and quality of life in moderate-severe PHPT, while data in mild PHPT are less clear. At variance, the effect of parathyroidectomy on neuromuscular and articular complications is still unknown, and no studies demonstrated a reduction of cancer risk after recovery from PHPT. Overall, to date, cardiovascular and neuropsychological evaluation are not recommended solely because of PHPT, nor cardiovascular disease, muscle weakness, and neuropsychological complications are indication for parathyroidectomy.

The effect of surgery on fat mass, lipid and glucose metabolism in mild primary hyperparathyroidism

CONTEXT

Mild primary hyperparathyroidism has been associated with increased body fat mass and unfavorable cardiovascular risk factors.

OBJECTIVE

To assess the effect of parathyroidectomy on fat mass, glucose and lipid metabolism.

DESIGN, PATIENTS, INTERVENTIONS, MAIN OUTCOME MEASURES

119 patients previously randomized to observation (OBS; n = 58) or parathyroidectomy (PTX; n = 61) within the Scandinavian Investigation of Primary Hyperparathyroidism (SIPH) trial, an open randomized multicenter study, were included. Main outcome measures for this study were the differences in fat mass, markers for lipid and glucose metabolism between OBS and PTX 5 years after randomization.

RESULTS

In the OBS group, total cholesterol (Total-C) decreased from mean 5.9 (±1.1) to 5.6 (±1.0) mmol/L (P = 0.037) and LDL cholesterol (LDL-C) decreased from 3.7 (±1.0) to 3.3 (±0.9) mmol/L (P = 0.010). In the PTX group, the Total-C and LDL-C remained unchanged resulting in a significant between-group difference over time (P = 0.013 and P = 0.026, respectively). This difference was driven by patients who started with lipid-lowering medication during the study period (OBS: 5; PTX: 1). There was an increase in trunk fat mass in the OBS group, but no between-group differences over time. Mean 25(OH) vitamin D increased in the PTX group (P < 0.001), but did not change in the OBS group. No difference in parameters of glucose metabolism was detected.

CONCLUSION

In mild PHPT, the measured metabolic and cardiovascular risk factors were not modified by PTX. Observation seems safe and cardiovascular risk reduction should not be regarded as a separate indication for parathyroidectomy based on the results from this study.

Cardiovascular manifestations of primary hyperparathyroidism: a narrative review

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

The intriguing connections of leptin to hyperparathyroidism

PURPOSE

Leptin has been implicated in bone metabolism, but the association with parathyroid gland function has not been fully clarified. This review aimed to summarize evidence of the association between leptin and hyperparathyroidism, both primary and secondary, elucidating the potential pathophysiologic and therapeutic consequences between leptin and parathyroid hormone, hopefully prompting the design of new studies.

RESULTS

Experimental studies indicate a positive loop between leptin and parathyroid hormone in primary hyperparathyroidism. Dissimilar, parathyroid hormone seems to inhibit leptin expression in severe secondary hyperparathyroidism. Data from clinical studies indicate higher leptin levels in patients with primary hyperparathyroidism than controls, but no association between parathyroid hormone and leptin levels, as well as a minimal or neutral effect of parathyroidectomy on leptin levels in patients with primary hyperparathyroidism. Clinical data on secondary hyperparathyroidism, mainly derived from patients with chronic kidney disease, indicate a potential inverse association between leptin and parathyroid hormone in some, but not all studies. This relationship may be affected by the diversity of morbidity among these patients.

CONCLUSIONS

Data from experimental studies suggest a different association between leptin and parathyroid hormone in primary and secondary hyperparathyroidism. Data from clinical studies are conflicting and potentially affected by confounders. More focused, well-designed studies are warranted to elucidate a potential association between leptin and parathyroid hormone, which may have specific clinical implications, i.e., targeting obesity and hyperleptinemia in patients with hyperparathyroidism.

Effect of Surgery Versus Observation: Skeletal 5-Year Outcomes in a Randomized Trial of Patients With Primary HPT (the SIPH Study)

Mild primary hyperparathyroidism (PHPT) is known to affect the skeleton, even though patients usually are asymptomatic. Treatment strategies have been widely discussed. However, long-term randomized studies comparing parathyroidectomy to observation are lacking. The objective was to study the effect of parathyroidectomy (PTX) compared with observation (OBS) on bone mineral density (BMD) in g/cm² and T-scores and on biochemical markers of bone turnover (P1NP and CTX-1) in a prospective randomized controlled study of patients with mild PHPT after 5 years of follow-up. Of 191 patients with mild PHPT randomized to either PTX or OBS, 145 patients remained for analysis after 5 years (110 with validated DXA scans). A significant decrease in P1NP (p < 0.001) and CTX-1 (p < 0.001) was found in the PTX group only. A significant positive treatment effect of surgery compared with observation on BMD (g/cm² ) was found for the lumbar spine (LS) (p = 0.011), the femoral neck (FN) (p < 0.001), the ultradistal radius (UDR) (p = 0.042), and for the total body (TB) (p < 0.001) but not for the radius 33% (Rad33), where BMD decreased significantly also in the PTX group (p = 0.012). However, compared with baseline values, there was no significant BMD increase in the PTX group, except for the lumbar spine. In the OBS group, there was a significant decrease in BMD (g/cm² ) for all compartments (FN, p < 0.001; Rad33, p = 0.001; UDR, p = 0.006; TB, p < 0.001) with the exception of the LS, where BMD was stable. In conclusion, parathyroidectomy improves BMD and observation leads to a small but statistically significant decrease in BMD after 5 years. Thus, bone health appears to be a clinical concern with long-term observation in patients with mild PHPT. © 2017 American Society for Bone and Mineral Research.

Calcium and Cardiovascular Disease

Circulating calcium is a risk factor for vascular disease, a conclusion arising from prospective studies involving hundreds of thousands of participants and extending over periods of up to 30 years. These associations may be partially mediated by other cardiovascular risk factors such as circulating lipid levels, blood pressure, and body mass index, but there appears to be a residual independent effect of serum calcium. Polymorphisms of the calcium-sensing receptor associated with small elevations of serum calcium are also associated with cardiovascular disease, suggesting that calcium plays a causative role. Trials of calcium supplements in patients on dialysis and those with less severe renal failure demonstrate increased mortality and/or acceleration of vascular disease, and meta-analyses of trials in those without overt renal disease suggest a similar adverse effect. Interpretation of the latter trials is complicated by a significant interaction between baseline use of calcium supplements and the effect of randomisation to calcium in the largest trial. Restriction of analysis to those who are calcium-naive demonstrates a consistent adverse effect. Observational studies of dietary calcium do not demonstrate a consistent adverse effect on cardiovascular health, though very high or very low intakes may be deleterious. Thus, obtaining calcium from the diet rather than supplements is to be encouraged.

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

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

Circulating calcium concentrations, vascular disease and mortality: a systematic review

Associations between serum calcium and vascular disease have been reported, but the consistency of these findings is unknown. We conducted a systematic review to determine whether circulating calcium concentrations are associated with risks of cardiovascular disease and death in normocalcaemic populations. We conducted PubMed searches up to 18 December 2014 and scrutinized reference lists of papers. Eligible studies related serum calcium to mortality or cardiovascular events in humans. A follow-up of at least one year was required for longitudinal studies. Studies in populations selected on the basis of renal disease or abnormal serum calcium were excluded. Two investigators performed independent data extraction. The results were tabulated and, where possible, meta-analysed. Five of 11 studies reported a statistically significant positive association between serum calcium and mortality. Meta-analysis of eight of these studies showed a hazard ratio of death of 1.13 (1.09, 1.18) per standard deviation of serum calcium. Eight of 13 studies reported a statistically significant positive association between serum calcium and cardiovascular disease. Meta-analysis of eight studies showed a hazard ratio of cardiovascular disease of 1.08 (1.04, 1.13) per standard deviation of serum calcium. For two studies reporting odds ratios, the pooled odds ratio per standard deviation was 1.22 (1.11, 1.32). When hazard ratios adjusted for cardiovascular risk factors were meta-analysed, the pooled hazard ratio was 1.04 (1.01, 1.08). Other studies demonstrated associations between serum calcium and stroke and between serum calcium and direct measurements of arterial disease and calcification. These observational data indicate that serum calcium is associated with vascular disease and death, but they cannot determine causality.

Parathyroidectomy Decreases Insulin Resistance Index in Patients with Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) has been considered a cause of insulin resistance (IR) and impaired glucose metabolism. However, there are conflicting results related with the recovery of insulin resistance in patients with PHPT following curative parathyroidectomy. Our aim is to evaluate the effects of curative parathyroidectomy on IR in patients with PHPT. This is a prospective interventional study. Twenty-one consecutive patients with symptomatic PHPT were included into the study. All patients underwent parathyroidectomy. Fasting serum glucose, calcium, phosphorous, parathormone, plasma insulin, and vitamin D levels were measured both at baseline and 2 months after parathyroidectomy. Insulin resistance was calculated by homeostasis of model assessment-insulin resistance (HOMA-IR). Two months after curative parathyroidectomy, serum levels of calcium (p = 0.001), PTH (p < 0.001), insulin (p = 0.003), and HOMA-IR (p = 0.003) decreased, while phosphorous levels increased (p = 0.001). During this period, no changes were observed at vitamin D and glucose levels. We concluded that curative parathyroidectomy decreases HOMA-IR index in patients with PHPT. Studies with larger population and longer follow-up period are required to confirm our results.

Parathyroidectomy in asymptomatic primary hyperparathyroidism reduces carotid intima-media thickness and arterial stiffness

OBJECTIVE

Although an International Workshop has suggested that cardiovascular assessment in asymptomatic primary hyperparathyroidism (PHPT) patients is not necessary, improvements in risk factors of subclinical atherosclerosis have been shown following parathyroidectomy. The objectives of this study were to determine whether parathyroidectomy in asymptomatic PHPT patients causes any change in carotid intima-media thickness (CIMT), arterial stiffness [pulse wave velocity (PWV)] and soluble CD40 ligand (sCD40L) levels.

DESIGN

Prospective study evaluating female patients diagnosed with asymptomatic PHPT in a single centre over a 6-month period.

PATIENTS

A total of 48 subjects were included: 17 hypercalcaemic (HC, mean age: 51 ± 8 years, Ca: 2·73 ± 0·17 mmol/l) and 16 normocalcaemic (NC, mean age: 58 ± 7 years, Ca: 2·30 ± 0·10 mmol/l) PHPT patients, and 15 healthy controls (mean age: 52 ± 4 years, Ca: 2·27 ± 0·07 mmol/l).

MEASUREMENTS

Biochemical tests, CIMT, PWV and sCD40L levels were compared at baseline and 6 months after parathyroidectomy (PTx).

RESULTS

At baseline, CIMT and PWV values in the HC and NC patients were higher than in the control group. While there was a significant reduction in CIMT (601 ± 91 μm vs 541 ± 65 μm, P = 0·006) and PWV (9·6 ± 1·8 vs 8·4 ± 1·5 m/s, P = 0·000) in the hypercalcaemic group at the end of the 6th month after PTx, no change was observed in normocalcaemic group (P = 0·686 and P = 0·196 respectively). No differences were observed in sCD40L levels between patient and control groups or between baseline and 6 months in patients undergoing parathyroidectomy.

CONCLUSION

Parathyroidectomy leads to an improvement in the structural and functional impairment associated with atherosclerosis in the vascular wall in asymptomatic hypercalcaemic PHPT patients.

Novel inflammatory biomarkers in primary hyperparathyroidism

OBJECTIVE

Primary hyperparathyroidism (PHPT) has been associated with low-grade inflammation and increased risk of cardiovascular disease (CVD). The aim of the study was to investigate systemic levels of pro-inflammatory proteins that previously have not been examined in patients with PHPT. The selection of the pro-inflammatory biomarkers included in this study, MMP9, S100A4, S100A8/A9 and the receptors sCD14 and RAGE, was based on a previous microarray screen of mRNAs in adipose tissue from PHPT patients.

DESIGN

A prospective study was conducted on a total of 57 patients with PHPT and a control group of 20 healthy blood donors.

METHODS

PHPT patients with normalisation of serum calcium levels after parathyroidectomy were followed for 6 months. Forty-two patients participated in the longitudinal study, in which blood samples were taken at inclusion, and 1, 3 and 6 months after surgery.

RESULTS

We observed increased serum levels of MMP9 (P=0.029), S100A4 (P<0.001) and sCD14 (P=0.002) in the 57 patients with PHPT compared to the control-group. During 6 months of follow up, S100A4 (P=0.022) and sCD14 (0.002) decreased significantly, while serum levels of MMP9 increased (P=0.025).

CONCLUSIONS

The results demonstrate an increased inflammatory response in PHPT patients shown by elevated MMP9, S100A4 and sCD14 at inclusion. During the 6 months of follow-up, MMP9 increased further, possibly due to the tissue repair process after parathyroidectomy. S100A4 and sCD14 decreased after surgery demonstrating a partial reversal of the systemic inflammation.

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

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