Normalized dyslipidaemia after parathyroidectomy in mild primary hyperparathyroidism: population-based study over five years

The unique association between serum 25-hydroxyvitamin D concentrations and blood lipid profiles in agriculture, forestry, and fishing occupations: Insights from NHANES 2001-2014

BACKGROUND

The relationship of serum 25(OH)D levels and hyperlipidemia has not been explored in the Agriculture, Forestry, and Fishing (AFF) occupation. We aimed to explore the impact of serum 25(OH)D levels on lipid profiles in AFF workers, traffic drivers, and miners.

METHODS

Data from 3937 adults aged 18-65 years old with completed information were obtained from the National Health and Examination Survey from 2001 to 2014. Multivariate linear regression models were used to examine the associations between serum 25(OH)D concentrations and triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and HDL-C/LDL-C ratio. Subgroup analyses for AFF workers considered age, sex, BMI, work activity, months worked, and alcohol consumption. Non-linear relationships were explored using curve fitting.

RESULTS

Serum 25(OH)D levels differed between groups (AFF: 60.0 ± 21.3 nmol/L, drivers: 56.6 ± 22.2 nmol/L, miners: 62.8 ± 22.3 nmol/L). Subgroup analysis of the AFF group showed that participants with serum 25(OH)D ≥50 nmol/L, females, and BMI <30 kg/m2 demonstrated improved HDL-C levels correlating with higher serum 25(OH)D. Serum 25(OH)D in AFF workers had a reversed U-shaped relationship with TG and TC, and a U-shaped relationship with HDL-C, with HDL-C, with inflection points at 49.5 nmol/L for TG and TC, and 32.6 nmol/L for HDL-C.

CONCLUSIONS

Serum 25(OH)D levels are associated with lipid profiles, and the relationship varies among occupational groups. AFF workers, facing unique occupational challenges, may benefit from maintaining adequate serum 25(OH)D levels to mitigate adverse lipid profiles and reduce cardiovascular risk.

Normohormonal primary hyperparathyroidism: A systematic review and meta-analysis

OBJECTIVE

We aim to evaluate the body of evidence reporting on normohormonal primary hyperparathyroidism (NHpHPT) patients to help guide their diagnosis, characterization and treatment.

BACKGROUND

Normohormonal primary hyperparathyroidism is a term used to describe patients with a normal PTH and elevated calcium levels. There is limited understanding regarding the presentation and appropriate management of these patients.

METHODS

A systematic review was conducted: abstract and full-text screening were independently conducted by 2 investigators. Odds ratios (OR), standard mean differences (SMD) and 95% confidence intervals were calculated.

RESULTS

Twenty-two studies were identified. Patients with NHpHPT were more likely to present with lower PTH (p < 0.00001) and calcium (p < 0.00001) levels. Intraoperatively, the NHpHPT group was 1.8 times more likely to undergo bilateral neck exploration (BNE) and harbor multigland disease. The rates of surgical cure were 93% in the NHpHPT and 96% in the pHPT groups (p = 0.0003).

CONCLUSION

Symptomatic patients with NHpHPT benefit from parathyroidectomy with prolonged intraoperative PTH monitoring, and a low threshold for conversion to BNE.

A Delicate Balance: Challenges in the Management of Primary Hyperparathyroidism and Congestive Heart Failure

Primary hyperparathyroidism (PHPT) is an excessive parathyroid hormone (PTH) production disorder, causing increased calcium levels. Commonly, these cases are asymptomatic and detected incidentally on routine labs. These patients are usually conservatively managed and monitored periodically, including bone and kidney health evaluation. Medical management of severe hypercalcemia secondary to PHPT includes IV fluids, cinacalcet, bisphosphonates, and dialysis, while the surgical treatment is parathyroidectomy. Patients suffering from heart failure with reduced ejection fraction (HFrEF) on diuretics and PHPT require a delicate balance of their volume status to prevent exacerbation of either condition. In patients with these two comorbidities on the opposite ends of the volume spectrum, it can lead to challenges in managing these patients. We present a case of a woman with repeated hospitalizations due to poor volume status control.  An 82-year-old female with primary hyperparathyroidism (diagnosed 17 years ago), HFrEF due to non-ischemic cardiomyopathy, sick sinus syndrome with a pacemaker, and persistent atrial fibrillation presented to the emergency department with worsening bilateral lower limb swelling for several months. The remaining review of systems was largely negative. Her home medication regimen included carvedilol, losartan, and furosemide. Vitals were stable, and the physical exam revealed bilateral lower extremity pitting edema. Chest x-ray revealed cardiomegaly with mild pulmonary vascular congestion. Relevant labs were NT pro-BNP at 2190 pg/mL, calcium at 11.2 mg/dL, creatinine at 1.0 mg/dL, PTH at 143 pg/mL, and Vitamin D, 25-hydroxy at 48.6 ng/mL. The echocardiogram showed an ejection fraction (EF) of 39%, grade III diastolic dysfunction, severe pulmonary hypertension, and mitral and tricuspid regurgitation. The patient received IV diuretics and guideline-directed treatment for congestive heart failure exacerbation. She was managed conservatively for her hypercalcemia and advised to maintain hydration at home. Spironolactone and Dapagliflozin were added to her regimen, and the Furosemide dose was increased at discharge.  The patient was re-admitted three weeks later with fatigue and decreased fluid intake. Vitals were stable; however, the physical exam revealed dehydration. Pertinent labs were calcium at 13.4 mg/dL, potassium at 5.7 mmol/L, creatinine at 1.7 mg/dL (baseline 1.0), PTH at 204 pg/mL, and Vitamin D, 25-hydroxy at 54.1 ng/mL. Repeat ECHO showed an ejection fraction (EF) of 15%. She was started on gentle IV fluids to correct the hypercalcemia while preventing volume overload. Hypercalcemia and acute kidney injury improved with hydration. She was put on Cinacalcet 30 mg, and home medications were adjusted for better volume control at discharge. This case highlights the complications of balancing the volume status with primary hyperparathyroidism and CHF. Worsening HFrEF resulted in a higher diuretic requirement, thereby worsening her hypercalcemia. With emerging data on the correlation between PTH and cardiovascular risks, it is becoming necessary to assess the risks and benefits of conservative management in asymptomatic patients. Current research has also shown that various patient demographics and comorbidities prevent the surgical management of PHPT. Hence, in suitable candidates, parathyroidectomy must be considered early in patients with asymptomatic hyperparathyroidism.

Primary hyperparathyroidism in young patients is associated with metabolic disorders: a prospective comparative study

BACKGROUND

Components of metabolic syndrome can be observed in patients with primary hyperparathyroidism (PHPT). The link between these disorders remains unclear due to the lack of relevant experimental models and the heterogeneity of examined groups. The effect of surgery on metabolic abnormalities is also controversial. We conducted a comprehensive assessment of metabolic parameters in young patients with PHPT.

METHODS

One-center prospective comparative study was carried out. The participants underwent a complex biochemical and hormonal examination, a hyperinsulinemic euglycemic and hyperglycemic clamps, a bioelectrical impedance analysis of the body composition before and 13 months after parathyroidectomy compared to sex-, age- and body mass index matched healthy volunteers.

RESULTS

45.8% of patients (n = 24) had excessive visceral fat. Insulin resistance was detected in 54.2% of cases. PHPT patients had higher serum triglycerides, lower M-value and higher C-peptide and insulin levels in both phases of insulin secretion compared to the control group (p < 0.05 for all parameters). There were tendencies to decreased fasting glucose (p = 0.031), uric acid (p = 0.044) and insulin levels of the second secretion phase (p = 0.039) after surgery, but no statistically significant changes of lipid profile and M-value as well as body composition were revealed. We obtained negative correlations between percent body fat and osteocalcin and magnesium levels in patients before surgery.

CONCLUSION

PHPT is associated with insulin resistance that is the main risk factor of serious metabolic disorders. Surgery may potentially improve carbohydrate and purine metabolism.

Parathyroid diseases and metabolic syndrome

PURPOSE

Parathyroid diseases are related to parathyroid hormone (PTH) dysregulation by parathyroid cells or alteration of PTH function. They include hyperparathyroidism (PTH excess), hypoparathyroidism (PTH deficiency) and pseudohypoparathyroidism (PTH resistance). Little is known about correlation between parathyroid diseases and metabolic syndrome (MetS).

METHODS

An electronic-based search using PubMed was performed until October 2022 and articles were selected based on relevance of title, abstract, English language and publication in peer-reviewed journals.

RESULTS

Possible association between PTH alterations and the diverse manifestation of MetS have been proposed and it could be supposed that MetS may negatively influence parathyroid diseases. Available data show significant association for hyperparathyroidism and pseudohypoparathyroidism.

CONCLUSIONS

This review highlights the possible implications between MetS and parathyroid diseases. Given the increasing MetS global prevalence and the higher parathyroid diseases awareness and diagnosis, it may be interesting to further explore the possible role of alterations in parathyroid homeostasis in the development of MetS components with dedicated prospective studies.

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.

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.

Diabetes and Bone Involvement in Primary Hyperparathyroidism: Literature Review and Our Personal Experience

BACKGROUND

Primary hyperparathyroidism (PHPT) and type 2 diabetes mellitus (T2DM) are common endocrine disorders impacting on skeletal health, whose concomitant occurrence is becoming more frequent.

PATIENTS AND METHODS

We searched the PubMed database from the National Library of Medicine about the relationship between T2DM and its treatment and bone manifestations of PHPT. Thereafter, we retrospectively evaluated a consecutive series of 472 PHPT patients. Among them 55 were also affected by T2DM. At the diagnosis of PHPT we compared bone turnover markers and bone densitometry between 55 patients with and 417 without T2DM and in the former group according to antidiabetic treatment.

RESULTS

Few data are available about T2DM and PHPT bone involvement, studies about T2DM treatments and PHPT bone manifestations are lacking. Among patients with PHPT of our series, those with T2DM were older, had a lower prevalence of osteitis fibrosa cystica, higher lumbar and femoral T-scores than the remaining patients. No difference was disclosed among the diabetic patients according to ongoing antidiabetic treatment, even though modern treatments were under-represented.

CONCLUSIONS

No clinical study specifically evaluated the impact of T2DM on bone involvement in PHPT. In our experience, diabetic patients resulted more frequently "mild asymptomatic" than non-diabetic patients and showed a lower prevalence of radiological PHPT bone manifestations. The treatment of T2DM does not seem to affect the biochemical or clinical features of PHPT in our series. Further studies are needed to fully disclose the influence of T2DM and antidiabetic treatment on bone health in patients with PHPT.

Parathyroid gland weight is associated with high density lipoprotein levels in patients with primary hyperparathyroidism

Objective

To investigate the relationship between parathyroid gland weight and high-density lipoprotein (HDL) levels in patients with primary hyperparathyroidism (PHPT).

Methods

In this retrospective case control study, we reviewed 329 PHPT patients aged from 20 to 85 years who had a parathyroidectomy at Robert Wood Johnson University Hospital. The patients were divided into 5 quintiles according to their parathyroid gland weight: 68 patients had a parathyroid gland weight <0.3 g, 66 patients had a gland weight 0.3–0.45 g, 67 patients had a gland weight 0.45–0.7 g, 63 patients had a gland weight 0.7–1.25 g, and 65 patients had a gland weight ≥1.25 g.

Results

Body Mass Index (BMI) trended to be higher across the quintiles of parathyroid gland weight (P = 0.003). Serum calcium and PTH levels were significantly increased across parathyroid gland quintiles (p < 0.0001). HDL levels tended to be lower across the increasing quintiles of parathyroid gland weight (P = 0.01). There was a negative relationship between log parathyroid gland weight and HDL in patients with PHPT in a simple linear regression (r = −0.160, P = 0.003). The negative association remained significant after adjustment for age and BMI (r = −0.114, P = 0.039). Furthermore, parathyroid gland weight was significantly associated with levels of triglyceride (r = 0.126, P = 0.02), but this relationship lost its significance after adjustment for age and BMI (r = 0.082, P ˃ 0.05).

Conclusions

PHPT patients with heavier parathyroid glands tended to have higher BMI and lower HDL levels.

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.

Parathyroidectomy improves cardiovascular risk factors in normocalcemic and hypercalcemic primary hyperparathyroidism

BACKGROUND

Parathyroidectomy has ameliorated cardiovascular risk factors in patients with hypercalcemic primary hyperparathyroidism (PHPT), but the effect of parathyroidectomy on normocalcemic PHPT is not exactly known. This case-controlled study aimed to investigate the effect of parathyroidectomy on cardiovascular risk factors in patients with normocalcemic and hypercalcemic PHPT.

METHODS

Subjects with normocalcemic PHPT (n = 35), age- and sex-matched hypercalcemic PHPT (n = 60) and age- and sex-matched control (n = 60) were included. Cardiometabolic disorders were investigated with traditional cardiometabolic risk factors and the Framingham cardiovascular risk score (CRS) before and 6 months after parathyroidectomy.

RESULTS

Diabetes, dyslipidemia, hypertension, obesity, insulin resistance, osteoporosis, having fractures were similarly increased in the hypercalcemic and normocalcemic PHPT groups (p > 0.05) compared with the controls (p < 0.05). Blood pressures, glucose metabolism (glucose, insulin, HOMA-IR) and lipid profiles were similarly increased in the PHPT groups (p > 0.05) compared with the controls (p < 0.05). After parathyroidectomy, blood pressures, serum total cholesterol, and HOMA-IR were decreased in both PHPT groups (p < 0.05). CRS was lower in the controls (5.74 ± 3.24, p < 0.05). After parathyroidectomy, CRS was decreased in the normocalcemic (11.98 ± 10.11 vs. 7.37 ± 4.48) and hypercalcemic (14.62 ± 11.06 vs. 8.05 ± 7.72) PHPT groups. Increased blood pressures were independent predictors of serum iPTH.

CONCLUSION

The normocalcemic and hypercalcemic PHPT groups had similarly increased cardiovascular risk factors, even independently of serum calcium. Parathyroidectomy ameliorated the increased cardiovascular risk factors in both normocalcemic and hypercalcemic PHPT.

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.

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.

Association of ADAMTS4 and ADAMTS9 levels with cardiovascular risk in patients with primary hyperparathyroidism

PURPOSE

Primary hyperparathyroidism (PHPT) has been associated with increased incidence of morbidity and mortality of the cardiovascular system. The pathogenetic mechanisms underlying this association are still not completely clear. A disintegrin and metalloproteinase with thrombospondin-like motifs (ADAMTS) play a critical role in atherosclerosis. This study aimed to investigate the levels of ADAMTS4 and ADAMTS9 and relationship between these proteoglycanases and cardiometabolic abnormalities in PHPT.

MATERIALS AND METHODS

A case-control study was performed in a training and research hospital. Fifty-six patients with PHPT and 61 healthy volunteers were recruited. The Framingham score was used to calculate cardiovascular risk (CVR). Serum ADAMTS levels were determined by a human enzyme-linked immunoassay in all subjects.

RESULTS

The ADAMTS9 concentration was significantly higher in patients with PHPT than in the control group (p < 0.05); however, there were no significant differences in ADAMTS4 levels between the groups (p > 0.05). In ROC curve analysis, PHPT can be predicted by the use of ADAMTS9 at a cut-off value of 30.7 pg/mL (69% sensitivity, 65% specificity). CVR score was significantly increased in the PHPT than controls (p < 0.05). ADAMTS4 and ADAMTS9 levels had positive correlations with CVR score (r = 0.322, p = 0.017; r = 0.275, p = 0.044 respectively).

CONCLUSIONS

Based on the results of the present study, cardiovascular risk is increased in PHPT and associated with ADAMTS4 and ADAMTS9. Further efforts are needed to establish the function of ADAMTS proteases in both PHPT and atherosclerosis.

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.

Intact parathyroid hormone levels and primary hyperparathyroidism

OBJECTIVE

The aim of this article is to compare clinical characteristics and lab values for metabolic syndrome between primary hyperparathyroidism (PHPT) patients with different levels of serum intact parathyroid hormone (iPTH) and to determine correlation between different clinical characteristics among PHPT patients Methods: We reviewed charts of 212 PHPT patients in this retrospective study. Patients were divided into two groups according to their initial serum iPTH levels. Student's t-tests were used to compare the two groups for differences in clinical characteristics and laboratory values. Pearson's correlation coefficients were used to assess associations.

RESULTS

Of the 212 PHPT patients, 100 were classified as m-iPTH group (serum iPTH < 140 pg/mL), whereas 112 patients were defined as h-iPTH group (serum iPTH ≥ 140 pg/mL). The h-iPTH patients were younger, had higher serum calcium and alkaline phosphatase levels, but exhibited lower 25(OH)-vitamin D and HDL levels, when compared with those of m-iPTH patients. Adenoma weights in the h-iPTH group tended to be higher than that in the m-iPTH group. Furthermore, association studies revealed that the iPTH level was positively correlated with adenoma weight and serum calcium and triglyceride (TG) levels but negatively correlated with HDL level.

CONCLUSION

Our study supports the hypothesis that iPTH level is associated with TG and HDL levels and should be a factor to consider in the management of PHPT patients.

Associations between serum levels of calcium, parathyroid hormone and future risk of venous thromboembolism: the Tromsø study

OBJECTIVE

The relationship between serum levels of calcium, parathyroid hormone (PTH) and risk of venous thromboembolism (VTE) has not been addressed in population-based cohorts. We investigated the associations between serum levels of calcium and PTH, with future risk of VTE in a general adult population.

DESIGN

Population-based cohort.

METHODS

A total of 27 712 subjects (25-87 years) who participated in Tromsø 4 (1994-1995) and Tromsø 5 (2001-2002) surveys were included in the study, and total calcium and PTH were measured in 27 685 and 8547 subjects respectively. Incident VTE was recorded through December 31, 2012. Cox-regression models with calcium and PTH as time-varying exposures were used to calculate hazard ratios (HR) of VTE by quartiles of calcium and PTH. Quartiles of calcium and PTH were also combined to assess the effect of discordants of both PTH and calcium (e.g. highest and lowest quartiles of both calcium and PTH) on VTE risk using the middle two quartiles as reference.

RESULTS

There were 712 VTEs during 15.0 years of median follow-up. Serum levels of calcium and PTH were not associated with risk of VTE. However, subjects with discordant high serum levels of both calcium and PTH (calcium ≥2.45 mmol/L and PTH ≥4.0 pmol/L) had increased risk of VTE compared to those in subjects with normal calcium and PTH (multivariable HR: 1.78, 95% CI: 1.12-2.84).

CONCLUSIONS

Serum levels of calcium and PTH separately were not associated with future risk of VTE, but subjects with high levels of both calcium and PTH had increased risk of VTE compared to those in subjects with normal levels.

Parathyroid hormone reflects adiposity and cardiometabolic indices but not bone density in normal men

Hyperparathyroidism may be associated with skeletal and cardiovascular abnormalities, but it is unclear whether these associations exist for high-normal levels of parathyroid hormone (PTH). We assessed relationships between PTH and anthropometric, skeletal and cardiometabolic indices in normal men. Body composition, blood pressure, biochemistry and bone mineral density (BMD) were evaluated in 151 healthy men. BMD was reassessed at 2 years, and coronary artery calcium (CAC) was measured at 3.5 years. Relationships between PTH and other baseline characteristics, CAC scores and change in BMD were evaluated. PTH correlated positively with baseline body mass index, fat mass, diastolic blood pressure, triglycerides, total and low-density lipoprotein (LDL) cholesterol, (r=0.19-0.25, P=0.02-0.002), and with category of CAC score. Relationships between PTH and cardiometabolic indices remained significant after adjustment for age, 25-hydroxyvitamin D and estimated glomerular filteration rate. Men in the top PTH tertile (⩾4.4 pmol l^-1, n=51) were more likely to have LDL cholesterol ⩾3.5 mmol l^-1, diastolic blood pressure ⩾85 mm Hg, and CAC score >0 than men in lower tertiles. PTH was not associated with history of fracture, baseline BMD, or change in BMD over 2 years. In summary, in this cohort of healthy men, PTH levels are linearly related to adiposity and to cardiometabolic indices, but not to BMD or bone loss. These findings suggest that adiposity should be considered as an independent cause of secondary hyperparathyroidism, and they may be relevant to patients with normocalcemic hyperparathyroidism, in whom high PTH levels may be a marker of adiposity and cardiometabolic risk rather than always indicating parathyroid autonomy.

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.

Patients with normocalcemic primary hyperparathyroidism may have similar metabolic profile as hypercalcemic patients

Primary hyperparathyroidism is well known to be associated with cardiovascular morbidity and mortality. However, it is unclear whether normocalcemic primary hyperparathyroidism (NC-PHPT) and hypercalcemic primary hyperparathyroidism (HC-PHPT) share the same risk factors. We aimed to determine prevalence of metabolic syndrome in NC-PHPT and compare metabolic syndrome parameters and insulin resistance in NC-PHPT subjects with those in HC-PHPT and control subjects. After excluding patients with secondary hyperparathyroidism, the study enrolled 25 patients with NC-PHPT, 24 patients with HC-PHPT and 30 age-gender matched controls. All participants were evaluated using the International Diabetes Federation (IDF)-2006 metabolic syndrome criteria. Compared with HC-PHPT patients, NC-PHPT patients had similar prevalence of metabolic syndrome, glucose intolerance, and previous history of hypertension/anti-hypertensive medications, but compared with controls, NC-PHPT patients had significantly higher prevalence of glucose intolerance and previous history of hypertension/anti-hypertensive medications. Not serum calcium but PTH concentration was found to be significantly higher in those with glucose intolerance. Serum fasting triglyceride concentration and waist circumference were found to be positively correlated only with serum PTH concentration. In conclusion, patients with NC-PHPT may be prone to similar metabolic disturbances linked to higher cardiovascular risk like patients with HC-PHPT. Although NC-PHPT is thought to occur early in the development of the classical disease, it should be monitored regularly because of its metabolic consequences.

Relationship Between Parathormone and Obesity-Linked Disorders

BACKGROUND

In this study, we aimed to investigate whether high parathormone (PTH) levels in obese patients contribute to the metabolic complications of obesity.

METHODS

A total of 400 obese subjects aged 18-65 years were included. Anthropometric bioelectrical bioimpedance measures, blood tests, and 75 gram oral glucose tolerance test results were evaluated.

RESULTS

Of the 400 obese subjects, 335 were female. The mean age was 39 ± 10 years. The median body mass index was 36 (interquartile range 34-41). Subjects were divided into quartiles according to blood PTH levels. Groups included quartile 1 [n = 100, median PTH; 42 (range 36-45)], quartile 2 [n = 100, median PTH; 55 (51-59)], quartile 3 [n = 100, median PTH; 73 (68-78)], and quartile 4 [n = 100, median PTH; 99 (89-125)]. Quartiles were evaluated with a generalized linear model adjusted for age, sex, and season of recruitment. Systolic and diastolic blood pressure, fasting glucose, homeostatic model assessment-estimated insulin resistance, insulin sensitivity index, triglyceride level, and high-density lipoprotein cholesterol (HDL-C) were not different among quartiles. PTH and 25 hydroxyvitamin D (25(OH)D) were not associated with higher odds of prevalent metabolic syndrome in obese subjects (odds ratio, OR, 0.99 [95% confidence interval, CI, 0.981.00], P = 0.38 and 0.99 95% CI 0.96-1.01], P = 0.46, respectively). Decreased 25(OH)D levels were significantly correlated with higher odds of low HDL-C (OR 0.96 [95% CI 0.93-0.99], P = 0.04).

CONCLUSIONS

PTH does not contribute to the occurrence of metabolic components of obesity, but there is a positive correlation between 25(OH)D and HDL-C.

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.

Mortality associated with primary hyperparathyroidism

561 patients with primary hyperparathyroidism were followed between 1961 and 1994. Relative survival was compared to that of the Australian population studied during the same time interval. Mortality was significantly greater in the hyperparathyroid population (P<0.001). Mortality was not greater in the patients with serum calcium levels >3.00 mmol/L compared to those with a serum calcium levels <3.00 mmol/L. 113 patients did not have parathyroid surgery. Their relative survival was not significantly different from those who had surgery but their mean serum calcium and parathyroid hormone (PTH) levels were significantly lower than those who had surgery. A re-analysis of the 453 patients followed between 1972 and 2011 was carried out and a 20-year survival analysis made of those diagnosed between 1972 and 1981 and those diagnosed between 1982 and 1991. The latter group had significantly worse relative mortality than the former group (P<0.001) but was significantly older at the time of diagnosis (56.94 ± 14.83 vs 52.01 ± 13.58, P<0.001). The serum calcium and serum PTH levels were not significantly different between these two groups.

Primary hyperparathyroidism and vitamin D deficiency

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

Cardiovascular risk and metabolic syndrome in primary hyperparathyroidism and their correlation to different clinical forms

Cardiometabolic disorders have been associated with primary hyperparathyroidism (PHPT), while the relationship of cardiovascular risk score (CRS) and metabolic syndrome (MS) with different clinical presentation of PHPT remains undefined. Our aim was to evaluate CRS, MS and its components in PHPT looking for their correlation to different clinical forms. In 68 consecutive PHPT patients and 68 matched controls, CRS, MS and its components were assessed to perform an observational case-control study at an ambulatory referral center for Bone Metabolism Diseases. Patients were stratified in symptomatic and asymptomatic PHPT; these latter were divided in high-risk and low-risk subgroups for end-organ damage. An increased proportion of PHPT patients had intermediate-high CRS and MS (mean, 95 % Confidence Interval (CI) 51.5 %, 39.6-63.3 and 20.6 %, 11.0-30.2, respectively, p < 0.02 vs. controls). Intermediate-high CRS was prevalent both in symptomatic and low-risk asymptomatic PHPT while MS resulted prevalent in low-risk asymptomatic but not in symptomatic PHPT. Type 2 DM, IFG, mixed dyslipidemia, hypertriglyceridemia, HDL-hypocholesterolemia, and LDL-hypercholesterolemia predominated in low-risk asymptomatic, while only LDL-hypercholesterolemia prevailed also in symptomatic PHPT. In patients and controls without cardiometabolic risk factors, HOMA-IR index was significantly increased in PHPT vs. controls (p < 0.03) and associated to total calcium (R = 0.73; p < 0.001). By multivariate analysis low-risk asymptomatic PHPT predicted MS after adjusting for age, sex, and BMI. Our data show an increased frequency of intermediate-high CRS both in symptomatic and low-risk asymptomatic PHPT while MS prevails in low-risk asymptomatic PHPT, supporting the potential for cardiovascular morbidity and mortality also in this form.

Mild primary hyperparathyroidism: a literature review

The biochemical profile of classic primary hyperparathyroidism (pHPT) consists of both elevated calcium and parathyroid hormone levels. The standard of care is parathyroidectomy unless prohibited by medical comorbidities. Because more patients are undergoing routine bone density evaluation and neck imaging studies for other purposes, there is a subset of people identified with a biochemically mild form of the pHPT that expresses itself as either elevated calcium or parathyroid hormone levels. These patients often do not fall into the criteria for operation based on the National Institutes of Health consensus guidelines, and they can present a challenge of diagnosis and management. The purpose of this paper is to review the available literature on mild pHPT in an effort to better characterize this patient population and to determine whether patients benefit from parathyroidectomy. Evidence suggests that there are patients with mild pHPT who have overt symptoms that are found to improve after parathyroidectomy. There is also a group of patients with biochemically mild pHPT who are found to progress to classic pHPT over time; however, it is not predictable which group of patients this will be. Early intervention for this group with mild pHPT may prevent progression of bone, psychiatric, and renal complications, and parathyroidectomy has proven safe in appropriately selected patients at high volume centers.

Subclinical and asymptomatic parathyroid disease: implications of emerging data

Primary hyperparathyroidism, a disorder in which there is a tendency for hypercalcaemia caused by autonomous overproduction of parathyroid hormone, is common, especially in postmenopausal women. Although parathyroidectomy is indicated for symptomatic patients, most individuals with the disorder are asymptomatic and without classic complications, such as renal stones and osteoporosis, at diagnosis. Consensus guidelines suggest which individuals might be suitable for medical follow-up rather than parathyroidectomy, but there are no long-term randomised controlled trials to support the safety of medical surveillance, and some patients progress with time. Data from observational studies suggest that cardiovascular morbidity and mortality are increased in patients with primary hyperparathyroidism, and might be predicted by parathyroid hormone concentrations, even in individuals with asymptomatic primary hyperparathyroidism. Whether parathyroidectomy improves cardiovascular outcomes in patients with asymptomatic primary hyperparathyroidism is unproven, but data suggest that surgery decreases fracture risk and might improve neuropsychological symptoms. Studies also show that patients with normocalcaemic (subclinical) hyperparathyroidism and hypoparathyroidism have a low risk of progression to overt disease, but their long-term risks are not defined. In this Review, we explore the increasing range of asymptomatic parathyroid disorders, focusing on current evidence about their natural history and potential complications, with a particular emphasis on primary hyperparathyroidism.

Evidence of a functional estrogen receptor in parathyroid adenomas

CONTEXT

Primary hyperparathyroidism (PHPT) is most frequently present in postmenopausal women. Although the involvement of estrogen has been suggested, current literature indicates that parathyroid tumors are estrogen receptor (ER) α negative.

OBJECTIVE

The aim of the study was to evaluate the expression of ERs and their putative function in parathyroid tumors.

DESIGN

A panel of 37 parathyroid tumors was analyzed for expression and promoter methylation of the ESR1 and ESR2 genes as well as expression of the ERα and ERβ1/ERβ2 proteins. Transcriptome changes in primary cultures of parathyroid adenoma cells after treatment with the selective ERβ1 agonist diarylpropionitrile (DPN) and 4-hydroxytamoxifen were identified using next-generation RNA sequencing.

RESULTS

Immunohistochemistry revealed very low expression of ERα, whereas all informative tumors expressed ERβ1 (n = 35) and ERβ2 (n = 34). Decreased nuclear staining intensity and mosaic pattern of positive and negative nuclei of ERβ1 were significantly associated with larger tumor size. Tumor ESR2 levels were significantly higher in female vs. male cases. In cultured cells, significantly increased numbers of genes with modified expression were detected after 48 h, compared to 24-h treatments with DPN or 4-hydroxytamoxifen, including the parathyroid-related genes CASR, VDR, JUN, CALR, and ORAI2. Bioinformatic analysis of transcriptome changes after DPN treatment revealed significant enrichment in gene sets coupled to ER activation, and a highly significant similarity to tumor cells undergoing apoptosis.

CONCLUSIONS

Parathyroid tumors express ERβ1 and ERβ2. Transcriptional changes after ERβ1 activation and correlation to clinical features point to a role of estrogen signaling in parathyroid function and disease.

Prevalence and characteristics of metabolic syndrome in primary hyperparathyroidism

AIMS

Primary hyperparathyroidism (pHPT) is characterized by an increased frequency of glucose tolerance abnormalities associated with insulin resistance. Few studies evaluated the prevalence of metabolic syndrome (MetS) in pHPT and whether there are differences between asymptomatic pHPT patients and symptomatic ones. Thus, we sought to investigate the prevalence of MetS in pHPT patients in comparison to the prevalence of MetS in Italian population.

SUBJECTS AND METHODS

We conducted a retrospective chart review of 294 pHPT patients, of these 154 [age (mean ± SD) 58.7 ± 13.3 yr, body mass index 25.6 ± 4.8 kg/m(2); serum calcium (11.3 ± 1.2 mg/dl) 2.8 ± 0.3 mmol/l; PTH 234.8 ± 224.3 ng/l] met the inclusion criteria. A modified National Cholesterol Educational Program (NCEP)/Adult Treatment Panel III (ATP III) definition of the MetS was used. Prevalence of MetS was compared with that reported for the Italian population (Progetto Cuore Study).

RESULTS

The prevalence of the MetS (34/154, 22.1%) was similar to that reported in the general Italian population. Asymptomatic pHPT patients were older (62.1 ± 12.7 vs 56.4 ± 13.2 yr, p<0.008) and showed higher prevalence of MetS than symptomatic ones (30.2% vs 16.5%, p<0.045). Moreover the prevalence of nephrolitiasis or overt bone disease was not different between patients MetS+pHPT compared to MetS-pHPT, whereas femoral bone mineral density (BMD) was higher in MetS+pHPT (p<0.003). In the logistic regression model age and femoral BMD were independent predictors of MetS.

CONCLUSIONS

The prevalence of MetS in pHPT is not increased in comparison to the general population, thus, its diagnosis is not an appropriate tool to identify the additional cardiovascular risk related to pHPT. Difference in age affects the increased prevalence of MetS in asymptomatic pHPT patients.

Investigation of insulin resistance in patients with normocalcemic primary hyperparathyroidism

While derangements in glucose metabolism in patients with primary hyperparathyroidism are well-defined, this issue is not investigated in patients with normocalcemic primary hyperparathyroidism (NPHPT). The aim of this study was to investigate the presence of insulin resistance in patients with NPHPT. Eighteen patients with NPHPT (two males and 16 females) and 18 healthy volunteers were enrolled into the study. Secondary causes of parathyroid hormone elevations were excluded in all patients. Blood samples were obtained for the measurement of serum calcium, phosphate, alkaline phosphatase (ALP), albumin, creatinine, glucose, and serum lipid levels. Glucose and insulin responses to oral glucose tolerance test (OGTT) were obtained. Homeostasis model assessment (HOMA-IR) was also used as an indice of insulin resistance. Patients and control subjects had similar age, body mass index, and sex distribution. Although within normal limits, serum calcium and ALP levels were higher in patients than in the control subjects. None of the patients and the control subjects had diabetes mellitus, while eight patients and six control subjects had impaired glucose tolerance. Insulin responses to OGTT and HOMA-IR were not significantly different among the patient and control subjects. In addition, both groups have similar serum lipid levels. Patients with NPHPT do not exhibit insulin resistance and glucose intolerance. Since so little is known about this form of disease, subjects should be monitored regularly for the metabolic aspects of the disease as well as the progression of their disease.

Improved long-term survival of dialysis patients after near-total parathyroidectomy

BACKGROUND

Severe secondary hyperparathyroidism, which is associated with life-threatening complications, can develop in dialysis-dependent end-stage renal disease patients. The aim of this study was to compare short- and long-term mortality in dialysis patients who underwent near-total parathyroidectomy (NTPTX) and matched nonoperated controls.

STUDY DESIGN

We identified 150 dialysis patients who underwent NTPTX (1993-2009) at our institution and compared them with 1,044 nonoperated control patients identified in the US Renal Data System registry, matched for age, sex, race, diabetes as cause of kidney failure, years on dialysis, and dialysis modality. Survival outcomes were estimated using multivariable Cox proportional hazards models with stratification on the matching sets, adjusted for cardiovascular comorbidities, smoking, inability to ambulate/transfer, and payor status.

RESULTS

During a follow-up of a mean of 3.6 years (range 0.1 month to 16.4 years), NTPTX patients had a significant reduction in the long-term risk of all-cause death (hazard ratio = 0.68; 95% CI, 0.52-0.89; p = 0.006) compared with controls. Thirty-day mortality rates for NTPTX patients and controls were 246 vs 105 per 1,000 person-years (p = 0.21). In adjusted analyses, NTPTX patients had a 37% reduced risk of all-cause death and a 33% reduced risk of cardiovascular death compared with controls. A durable reduction in mean parathyroid hormone was observed after NTPTX; from 1,776 ± 1,416.6 pg/mL to 301 ± 285.7 pg/mL (p < 0.0001).

CONCLUSIONS

In our center, NTPTX in dialysis patients was associated with a significant reduction in long-term risk of death compared with matched control patients, without a significantly increased short-term risk.

Arterial Hypertension, Metabolic Syndrome and Subclinical Cardiovascular Organ Damage in Patients with Asymptomatic Primary Hyperparathyroidism before and after Parathyroidectomy: Preliminary Results

Background. Primary hyperparathyroidism (PHPT) is associated with high cardiovascular morbidity, and the role of calcium and parathyroid hormone is still controversial. Objective. To evaluate the prevalence and outcomes of metabolic syndrome, hypertension, and some cardiovascular alterations in asymptomatic PHPT, and specific changes after successful parathyroidectomy. Material and Methods. We examined 30 newly diagnosed PHPT patients (8 males, 22 females; mean age 56 ± 6 yrs), 30 patients with essential hypertension (EH) (9 males, 21 females; mean age 55 ± 4), and 30 normal subjects (NS) (9 males, 21 females: mean age 55 ± 6). All groups underwent evaluation with ambulatory monitoring blood pressure, echocardiography, and color-Doppler artery ultrasonography and were successively revaluated after one year from parathyroidectomy. Results. PHPT patients presented a higher prevalence of metabolic syndrome (38%) with respect to EH (28%). Prevalence of hypertension in PHPT was 81%, and 57% presented altered circadian rhythm of blood pressure, with respect to EH (35%) and NS (15%). PHPT showed an important myocardial and vascular remodelling. During follow-up in PHPT patients, we found significant reduction of prevalence of metabolic syndrome, blood pressure, and "non-dipping phenomenon." Conclusions. Cardiovascular and metabolic alterations should be considered as added parameters in evaluation of patients with asymptomatic PHPT.

Should 'mild primary hyperparathyroidism' be reclassified as 'insidious': is it time to reconsider?

Primary hyperparathyroidism (PHPT) is a common incidental finding on routine biochemical testing, affecting around 1% of the population. The majority of individuals will be asymptomatic at diagnosis, with no evidence of end organ damage, and unless individuals aged <50 years at diagnosis, they are often considered to have 'mild' PHPT, as they do not meet published criteria for parathyroidectomy (PTX). However, there is increasing evidence that 'mild' PHPT is associated with adverse health outcomes. Long-term observational studies describing the natural history of 'mild' PHPT suggest that even though biochemistry may be relatively stable in the majority, bone mineral density (BMD) does decline after approximately 10 years of observation, whereas significant improvements in BMD are seen following PTX. Recent large European record linkage studies of 'mild PHPT' demonstrate significantly increased all-cause and cardiovascular mortality, similar to rates published for patients with PHPT who meet the NIH surgical criteria. 'Mild' PHPT was also associated with increased admissions for nonfatal cardiovascular disease, renal failure, renal stones, fractures, hypertension, psychiatric disease, cancer and diabetes, suggesting that 'insidious' PHPT may be a more appropriate description, or at least that the term 'mild' should be abandoned. Randomized controlled trials (RCTs) have begun to explore the benefits of PTX in this condition, demonstrating improvements in BMD and some psychiatric outcomes at approximately 2 years of follow-up. However, larger, adequately powered, long-term, RCTs will be required to determine whether PTX improves potential long-term morbidity and mortality in patients with PHPT who do not meet standard surgical criteria.

Primary hyperparathyroidism: Skeletal and non-skeletal effects, diagnosis and management

Primary hyperparathyroidism (PHPT) is the third most common endocrinopathy seen today, and is most frequently found in the 6th to 7th decade of life. PHPT can present with various degrees of symptoms, and can affect many organ systems, including the skeletal, renal, central nervous system and cardiovascular system. Despite this, the most common presentation of hyperparathyroidism is "asymptomatic" with the diagnosis being made incidentally with the initial finding of hypercalcemia on routine laboratory studies, leading to further investigation. Surgical versus medical management is usually based on factors such as age and complications related to hyperparathyroidism (i.e. the presence of renal stones, renal insufficiency and bone loss and significant increases in serum calcium). Treatment options include parathyroidectomy, bisphosphonates, calcitonin and calcimimetics. In this review, we discuss primary hyperparathyroidism in detail with a focus on clinical manifestations particularly in the elderly population. We highlight the indications for surgical versus medical management and compare some of the uses of newer therapeutic agents relative to traditional ones.

Medication discontinuation after curative surgery for sporadic primary hyperparathyroidism

BACKGROUND

Although parathyroidectomy (Ptx) for sporadic primary hyperparathyroidism (PH) improves comorbidities and symptoms, routine Ptx for minimally symptomatic PH remains controversial. Whether successful Ptx translates into discontinuation or dose-reduction of prescribed medications is unknown.

METHODS

Consecutive patients undergoing curative Ptx for sporadic PH from January 2007 to April 2009 were compared to patients undergoing thyroidectomy (Tx). We reviewed patient demographics, symptoms, comorbid conditions, and pre- and postoperative medications utilizing the Fisher exact test and t test for comparisons.

RESULTS

Compared to 176 Tx patients, 260 Ptx patients were older (P < .001), more commonly men (P = .006), and had higher preoperative prevalences of every examined PH symptom and comorbid condition. Postoperatively, even minimal PH symptoms improved after Ptx. The mean number of preoperative medications was higher in Ptx patients (4 vs 2.8, P < .001). Discontinuation or dose-reduction of medication occurred in 28 (11%) Ptx patients vs 7 (4%) Tx patients (P = .01). After Ptx, symptom improvement was the predominant reason for beneficial medication changes, and the most common beneficial effect was discontinuation or dose-reduction of chronic analgesics (33%).

CONCLUSION

PH symptoms are numerous and improve after curative Ptx. Medication use for related symptoms can be beneficially reduced by surgery. Drug profiles should be routinely reviewed and adjusted after parathyroidectomy.

Leptin: the link between overweight and primary hyperparathyroidism?

Primary hyperparathyroidism is one of the most common causes of hypercalcemia. Most cases result from sporadic benign monoclonal adenomas or hyperplasia. Increased body weight is consistently present in cohorts of patients with primary hyperparathyroidism. It has been shown that fat mass is the major determinant of serum parathyroid hormone levels independent of vitamin D status. Leptin, an adipocyte-derived hormone with mitogenic activity, regulates energy homeostasis and mineral metabolism. Serum leptin levels increase in parallel to the amount of adipose stores. Interestingly, a positive association between leptin and parathyroid hormone levels is observed. Patients with primary hyperparathyroidism have higher serum leptin levels than healthy subjects. In addition, leptin administration in mice increases circulating levels of parathyroid hormone. We hypothesize that leptin involves pathogenesis of primary hyperparathyroidism and represents a link between hyperparathyroidism and increased body weight.

Cardiac function in mild primary hyperparathyroidism and the outcome after parathyroidectomy

OBJECTIVE

Primary hyperparathyroidism (PHPT) is associated with cardiovascular morbidity. The extent of cardiovascular abnormalities in patients with mild-asymptomatic disease is unclear. Using sensitive echocardiographic methods, we compared cardiac structure and function in patients with mild PHPT and in healthy controls, and evaluated the changes after parathyroidectomy (PTX).

METHODS

In a prospective case-control design, we studied 51 PHPT patients without any cardiovascular risk factors/diseases and 51 healthy matched controls. Cardiac structure, and systolic and diastolic function were evaluated by echocardiography and Doppler tissue imaging (DTI). Blood pressure (BP) and heart rate were measured.

RESULTS

We observed no differences in systolic or diastolic function or in cardiac morphology between the PHPT patients and the age-matched healthy controls. The regional peak systolic myocardial velocities (S') measured with DTI decreased at all sites (P<0.05) after PTX (tricuspid annulus 14.23+/-1.85 to 13.48+/-1.79, septal 8.48+/-0.96 to 7.97+/-0.85, and lateral 9.61+/-2.05 to 8.87+/-1.63 cm/s, part of the mitral annulus). At baseline, systolic BP was higher in patients compared to controls (127.6+/-17.1 vs 119.6+/-12.6 mmHg, P<0.05). After PTX, both systolic (127.6+/-17.1 vs 124.6+/-16.6 mmHg, P<0.05) and diastolic (80.3+/-9.6 vs 78.4+/-8.6 mmHg, P<0.05) BP decreased.

CONCLUSIONS

Our results indicate that patients with PHPT without cardiovascular risk factors have a normal global systolic and diastolic function and cardiac morphology. BP and the systolic velocities were marginally reduced after PTX, but reflected the values of the control group. Our findings warrant further investigation of the clinical and prognostic significance of these possibly disease-related inotropic effects.

Plasma parathyroid hormone and risk of congestive heart failure in the community

AIMS

In experimental studies parathyroid hormone (PTH) has been associated with underlying causes of heart failure (HF) such as atherosclerosis, left ventricular hypertrophy, and myocardial fibrosis. Individuals with increased levels of PTH, such as primary or secondary hyperparathyroidism patients, have increased risk of ischaemic heart disease and HF. Moreover, increasing PTH is associated with worse prognosis in patients with overt HF. However, the association between PTH and the development HF in the community has not been reported.

METHODS AND RESULTS

In a prospective, community-based study of 864 elderly men without HF or valvular disease at baseline (mean age 71 years, the ULSAM study) the association between plasma (P)-PTH and HF hospitalization was investigated adjusted for established HF risk factors (myocardial infarction, hypertension, diabetes, electrocardiographic left ventricular hypertrophy, smoking, and hypercholesterolaemia) and variables reflecting mineral metabolism (S-calcium, S-phosphate, P-vitamin D, S-albumin, dietary calcium and vitamin D intake, physical activity, glomerular filtration rate, and blood draw season). During follow-up (median 8 years), 75 individuals were hospitalized due to HF. In multivariable Cox-regression analyses, higher P-PTH was associated with increased HF hospitalization (hazard ratio for 1-SD increase of PTH, 1.41, 95% CI 1.12-1.77, P = 0.003). Parathyroid hormone also predicted hospitalization in participants without apparent ischaemic HF and in participants with normal P-PTH.

CONCLUSION

In a large community-based sample of elderly men, PTH predicted HF hospitalizations, also after accounting for established risk factors and mineral metabolism variables.  Our data suggest a role for PTH in the development of HF even in the absence of overt hyperparathyroidism.

Insulin resistance before and after parathyroidectomy in patients with primary hyperparathyroidism--a pilot study

BACKGROUND

Primary hyperparathyroidism (PHPT) is associated with insulin resistance and an increased cardiovascular mortality. We aimed to see if parathyroidectomy improved insulin resistance.

METHODS

Twelve PHPT patients undergoing parathyroidectomy and ten control patients undergoing non-neck surgery were recruited to the study. Fasting venous blood samples were collected immediately pre-operatively and again at five to six weeks post-operatively. Samples were assayed for plasma glucose, serum insulin, total cholesterol, triglycerides, calcium, alkaline phosphatase, magnesium, parathyroid hormone (PTH), and haemoglobin A1c (HbA1c). Insulin resistance was calculated from fasting insulin and glucose values using Homeostasis Model Assessment (HOMA).

RESULTS

Parathyroidectomy decreased serum calcium (mean pre-op = 2.85 mmol/L, post-op 2.28 mmol/L, P < 0.001) and PTH concentrations (mean pre-op = 23.33 pmol/L, post-op = 10.23 pmol/L, P < 0.001) and increased phosphate concentration. However, there was no improvement in insulin resistance in the PHPT group at between 5 and 6 weeks post-operatively (geometric mean; pre-op = 0.88 (95% CI 0.59 - 1.33) vs. post-op = 0.88 (0.66 - 1.17) P = 0.95). In the control group, an increase in serum calcium was observed post-operatively (mean pre-op = 2.29 mmol/L, post-op = 2.35 mmol/L, P = 0.03). No change in insulin resistance was observed (geometric mean; pre-op = 1.37 (95% CI 0.89 - 2.11) vs. post-op = 1.38 (0.72 - 2.67) P = 0.96).

CONCLUSION

In summary, no significant change in insulin resistance post-parathyroidectomy in patients with PHPT was observed. This indicates that surgical treatment of PHPT does not improve insulin resistance for patients currently selected for parathyroidectomy.

Cardiac structure and diastolic function in mild primary hyperparathyroidism

CONTEXT

Data on the presence, extent, and reversibility of cardiovascular disease in primary hyperparathyroidism (PHPT) are conflicting.

OBJECTIVE

To evaluate the heart in PHPT, we assessed cardiac structure and diastolic function in patients with mild PHPT compared with age- and sex-matched controls.

DESIGN

This was a case-control study.

SETTINGS

The study was conducted in a university hospital Metabolic Bone Diseases Unit.

PARTICIPANTS

Fifty-four men and women with PHPT and 76 controls without PHPT participated in the study.

OUTCOME MEASURES

We measured left ventricular mass index (LVMI), the presence of mitral annular calcification, the ratio of early to late diastolic mitral inflow velocities (E/A), and early diastolic velocity of the lateral mitral annulus using Doppler tissue imaging (tissue Doppler e').

RESULTS

Patients had mild disease with mean (+/-sd) serum calcium 10.5 +/- 0.5 mg/dl and PTH 96 +/- 45 pg/ml. LVMI and diastolic function were normal in PHPT. There was no difference in LVMI (98 +/- 23 vs. 96 +/- 24 g/m(2), P = 0.69) or the frequency of mitral annular calcification between PHPT cases and controls. Diastolic function variables (E/A and tissue Doppler e') were higher (better) in cases compared with controls, although both were within the reference range. PHPT patients with low E/A had higher serum PTH (121 +/- 36 vs. 89 +/- 46 pg/ml, P = 0.03) and calcium (10.8 +/- 0.4 vs. 10.5 +/- 0.5 mg/dl, P = 0.05) than those with normal values. Finally, we found LVMI to be inversely associated with serum 25-hydroxyvitamin D in PHPT (r = -0.29, P < 0.05). All findings persisted after adjustment for group differences in cardiovascular risk factors.

CONCLUSIONS

Patients with biochemically mild PHPT do not have evidence of increased left ventricular mass, diastolic dysfunction, or increased valvular calcifications. However, the data support an association between low vitamin D levels and the development of left ventricular hypertrophy in this disorder. Finally, the increased serum calcium and PTH levels in those with diastolic dysfunction suggest that disease severity may determine the presence of cardiac manifestations in PHPT.

Nonoperative management of primary hyperparathyroidism: the exception rather than the rule

The spectrum of classical primary hyperparathyroidism (pHPT) has expanded from a disabling disease to a largely asymptomatic one, leading to considerable uncertainty regarding which patients with pHPT will truly benefit from operative therapy. In the hands of an experienced endocrine surgeon, parathyroidectomy (PTx) is associated with a greater than 95% cure rate and long-term complication rates of less than 5%. We believe that all patients with pHPT should be referred to an experienced endocrine surgeon for consideration of PTx. Furthermore, our preference is to offer surgical intervention to all patients with pHPT who do not have prohibitive medical comorbidities. The purpose of this article is to outline the anticipated benefits of PTx in patients with nonclassical symptoms of pHPT with regard to improvement of the present condition, prevention of future complications or both.

Correlation between plasma calcium, parathyroid hormone (PTH) and the metabolic syndrome (MetS) in a community-based cohort of men and women

CONTEXT

In recent years, an association has been noted between several abnormalities that characterize the metabolic syndrome (MetS) and primary hyperparathyroidism (pHPT). These abnormalities include dyslipidaemia, obesity, insulin resistance and hypertension. The correlations between plasma calcium, parathyroid hormone (PTH) and the variables in the MetS in a normal population are still unclear.

OBJECTIVE

To describe correlations between plasma calcium and PTH and the various abnormalities present in the MetS in a healthy population.

DESIGN

We studied 1016 healthy individuals from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) population of 70 years old, by means of plasma analyses of calcium, PTH, creatinine, lipids, insulin and glucose, as well as by standardized blood pressure measurements. Further, body mass index (BMI) and waist circumference were determined.

RESULTS

The more National Cholesterol Education Program (NCEP) criteria for the MetS that were met, the higher the s-PTH and albumin-corrected s-calcium. Further, positive correlations between plasma calcium and BMI (P = 0.0003), waist circumference (P = 0.0009) and insulin resistance (P = 0.079) were found. PTH and BMI (P < 0.0001), waist circumference (P < 0.0001), systolic blood pressure (P = 0.0034), diastolic blood pressure (P = 0.0008), serum triglycerides (P = 0.0003) and insulin resistance (P = 0.0003) were positively correlated, whereas serum high density lipoproteins (HDL) (P = 0.036) and PTH were negatively correlated.

CONCLUSIONS

We conclude that PTH correlates with several of the metabolic factors included in the MetS within a normocalcaemic population. In addition, individuals with mild pHPT present significantly more NCEP criteria for MetS. We postulate that increased levels of PTH in pHPT may be associated with the increased cardiovascular morbidity and mortality seen in pHPT.

Effect of surgery on cardiovascular risk factors in mild primary hyperparathyroidism

CONTEXT

Mild primary hyperparathyroidism (pHPT) seems to have a good prognosis, and indications for active treatment (surgery) are widely discussed. The extraskeletal effects of PTH, such as insulin resistance, arterial hypertension, and cardiovascular (CV) risk, may however be reversible by operation.

OBJECTIVE

Our aim was to study biochemical markers of bone turnover, indices of the metabolic syndrome, and various risk markers for CV disease in patients with mild pHPT randomized to observation without surgery or operative treatment and followed for 2 yr.

DESIGN/SETTING/PATIENTS

A total of 116 patients (mean age, 63 +/- 8 yr; 19 men and 97 women) who on May 1, 2008, had performed the 2-yr visit in a randomized study on mild pHPT (serum calcium at baseline, 2.69 +/- 0.11 mmol/liter) and where frozen samples were available from baseline and follow-up participated in the study.

RESULTS

Calcium and PTH levels were normalized after surgery, and biochemical markers of bone turnover decreased by 35%, followed by a significant increase in BMD in the spine (2.7%; P < 0.01) and femoral neck (1.1%; P < 0.02) compared with the observation group. No significant differences were observed between the groups for blood pressure, markers of insulin resistance, detailed cholesterol metabolism, adipokines, or parameters of inflammation and CV surrogate markers.

CONCLUSIONS

We observed expected effects on biochemical markers of bone turnover and bone mass after surgical treatment of mild pHPT, with stable values in the group randomized to observation. For a variety of measures of the metabolic syndrome, adipokines, and CV risk factors, no benefit of operative treatment could be demonstrated. Neither did we observe any deleterious effects of conservative management in the 2-yr perspective.

Increased plasminogen activator inhibitor-1, decreased tissue factor pathway inhibitor, and unchanged thrombin-activatable fibrinolysis inhibitor levels in patients with primary hyperparathyroidism

BACKGROUND AND OBJECTIVES

Primary hyperparathyroidism (PHPT) is associated with increased cardiovascular mortality and morbidity. Little is known about hemostatic features of patients with PHPT. To our knowledge, plasma tissue factor pathway inhibitor (TFPI) and thrombin-activatable fibrinolysis inhibitor (TAFI) levels in these patints have not been investigated. Therefore, the main purpose of this study was to evaluate the markers of endogenous coagulation/fibrinolysis, including TFPI and TAFI, and to investigate the relationships between serum calcium and PTH and these hemostatic parameters in patients with PHPT.

DESIGN AND METHODS

Twenty-four patients with PHPT and 20 age-, sex-, and-weight-matched healthy controls were included in the study. Tissue plasminogen activator (t-PA), tissue plasminogen activator inhibitor-1 (PAI-1), TFPI, and TAFI were measured. The relationships between serum calcium, phosphorus, and PTH and these hemostatic parameters were examinated.

RESULTS

Compared with the control subjects, t-PA, PAI-1, and PAI-1/t-PA ratios were significantly increased in patients with PHPT (P<0.0001), whereas TFPI levels were significantly decreased (P<0.0001). Plasma TAFI Ag levels did not significantly change in patients with PHPT compared with the controls. In patients with PHPT, serum phosphorus was negatively correlated with plasma PAI-1 Ag levels and PAI-1/t-PA ratio (r: -0.453, P<0.05; r: -0.580, P<0.01 respectively). There was a positive correlation between Cl/P ratio and plasma PAI-1 levels and PAI-1/t-PA ratio (r: 0.434, P<0.05; r: 0.528, P<0.05 respectively). iPTH was positively correlated with plasma PAI-1/t-PA ratio (r: 0.429, P<0.05).

INTERPRETATION AND CONCLUSIONS

In conclusion, we found some important differences in the hemostatic parameters between the patients with PHPT and healthy controls. Increased PAI-1, PAI-1/t-PA ratios and decreased TFPI levels in these patients represent a potential hypercoagulable and hypofibrinolytic state, which might augment the risk for atherosclerotic and atherothrombotic complications. This condition may contribute to the excess mortality due to cardiovascular disease seen in patients with PHPT.