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

Asymptomatic hyperparathyroidism--need for multicentre studies

Long-term follow-up is initially considered appropriate for the majority of patients with primary hyperparathyroidism (PHPT) having small increases in calcium levels (< 2.8 mmol/l) and lacking the 'classical' symptoms of PHPT. The supportive reasoning is that many such patients never progress to more severe biochemical or clinical disease. There are, however, arguments in favour of early surgical treatment of such patients but adequately powered studies have not been carried out in this subgroup of patients to asses the impact of PHPT on their quality of life, cardiovascular risk and bone density. Progressive loss in bone mineral density and an increased risk of bone fracture become increasingly significant in an ageing population. Left ventricular hypertrophy, an increased risk of arrhythmia and/or myocardial infarction in addition to changes in atherogenic lipid profile and impaired glucose tolerance may translate into an increased risk of premature death in this group of patients. Changes in the quality of life identified using standardized questionnaires are sometimes recognized by patients only in retrospect (i.e. after resolution of symptoms following successful parathyroidectomy). In addition, many series fail to assess and record accurately such symptoms. Multicentre cohort studies of patients with asymptomatic PHPT randomized to immediate or delayed surgical treatment could address some of the debated issues highlighted in this review. Until such studies are set up, most surgeons would consider that parathyroid surgery should represent the first choice of treatment for all patients, but many physicians would favour a long-term follow-up. Nevertheless, the threshold for referral for surgical treatment has been lowered since the introduction of scan-directed minimally invasive parathyroidectomy, which enables the experienced parathyroid surgeon to successfully treat patients with PHPT with a minimum of complications as a day-case operation. In the context of improved surgical treatment, we need more data on the benefits or otherwise in so-called asymptomatic patients with a thorough assessment of their bone quality, cardiovascular risk and quality of life.

Disturbances of calcium homeostasis consistent with mild primary hyperparathyroidism in premenopausal women and associated morbidity

CONTEXT

Primary hyperparathyroidism (PHPT) and associated morbidity are comprehensively assessed in elderly females; however, less is known of the disease in younger women.

OBJECTIVES

Our objectives were to estimate the prevalence of mild disturbances in calcium homeostasis, which could be analogous with early PHPT, in a premenopausal population, and determine the potential presence of associated morbidity.

DESIGN

Initial results from this longitudinal study are from 2002-2004.

SETTING

We conducted a population-based screening of serum (s)-calcium in conjunction with routine mammography.

PARTICIPANTS

Participants included premenopausal women, 40-50 yr of age (n = 1900). Cases fulfilling previously evaluated biochemical criteria for PHPT (n=214) were matched to controls (n = 214).

MAIN OUTCOME MEASUREMENTS

All participants underwent investigation, including screening of parameters of calcium homeostasis, dual x-ray absorptiometry, and body mass index assessment, and filled out extensive health and quality of life (SF-36) questionnaires. Participants were divided into four groups depending on the relation between s-calcium/intact PTH. Statistical comparisons between cases and controls as well as among the four groups were performed to evaluate morbidity.

RESULTS

The prevalence of assumed mild PHPT, i.e. inappropriate intact PTH value in relation to total s-calcium, was estimated to be 5.1% (n = 96). Women with mild disturbances in calcium homeostasis had statistically significant lower bone mineral density in the proximal femur and femoral neck, higher body mass index, and lower scores for vitality and general health in the analysis of SF-36.

CONCLUSIONS

Mild disturbances in calcium homeostasis in premenopausal women were more prevalent than previously thought and were associated with obesity, lower bone mineral density, and decreased quality of life.

Alanine to serine polymorphism at position 986 of the calcium-sensing receptor associated with coronary heart disease, myocardial infarction, all-cause, and cardiovascular mortality

BACKGROUND

Disorders of calcium homeostasis have been implicated in atherosclerosis. The calcium-sensing receptor (CASR) is crucial to the regulation of calcium metabolism. An alanine (A) to serine (S) polymorphism at codon 986 (A986S) of the CASR gene has been associated with higher calcium and osteoporosis; the association with coronary artery disease (CAD) has not been studied.

METHODS AND RESULTS

We investigated this polymorphism in individuals with CAD (n = 2561), including survivors of myocardial infarction (MI) (n = 1358) compared to 698 controls without angiographic CAD. Compared to AA homozygotes, the prevalence of CAD [multivariate odds ratio 1.25; 95% confidence interval (CI) 1.02-1.54] and previous MI (multivariate odds ratio 1.33; 95% CI 1.06-1.68) was increased in carriers of at least one S-allele. With each S-allele, the prevalence of CAD and MI increased 1.22-fold (95% CI 1.02-1.47) and 1.30-fold (95% CI 1.06-1.60), respectively. Fully adjusted hazard ratios for total and cardiovascular mortality per one S-allele were 1.24 (95% CI 1.05-1.46) and 1.38 (95% CI 1.13-1.67), respectively. In carriers of at least one S-allele, the adjusted hazard ratios for all-cause and cardiovascular death were 1.25 (95% CI 1.04-1.51) and 1.48 (95% CI 1.18-1.86), respectively. These associations were independent of cardiovascular risk factors, calcium and phosphate. The S-allele was associated with higher calcium (P < 0.001) and PTH (P < 0.02), and lower phosphate (P < 0.003) in CAD patients and controls.

CONCLUSION

Serine at position 986 of CASR may be an independent genetic predictor of angiographic CAD, previous MI, and cardiovascular mortality.

Serum Levels of Uric Acid and Diabetes Mellitus Influence Survival after Surgery for Primary Hyperparathyroidism: A Prospective Cohort Study

BACKGROUND

Primary hyperparathyroidism (pHPT) is associated with an increased mortality attributable to cardiovascular disease (CVD), suggested to be alleviated by surgery. The exact mechanism of the beneficial influence of parathyroidectomy on survival is unknown. Furthermore, studies suggest that there is no increased mortality compared to the mortality rate in the general population during recent years. This study therefore investigated relative survival (RS), as well overall mortality associated with the clinical and biochemical variables in patients undergoing operation for sporadic pHPT. Furthermore, the influence of surgery on biochemical variables associated with pHPT was analyzed.

METHODS

A group of 323 patients with sporadic pHPT operated between September 1989 and July 2003 were followed from surgery over a 10-year period. The median and mean follow-up time was 69 and 70 months, respectively (range: 1-120 months). Relative survival (RS) was calculated, and the impact of clinical and biochemical variables on overall death were evaluated.

RESULTS

Postoperatively, serum levels of triglycerides and uric acid decreased. Glucose levels and glomerular filtration rate remained unchanged. A decreased RS was evident during the latter part of the 10 year follow-up period. In the multivariate Cox-analysis, diabetes mellitus (hazard ratio [HR] = 2.8, 95%; confidence interval [CI] 1.2-6.7), and the combination of an increased level of serum uric acid and cardiovascular disease (CVD) (HR = 8.6, 95%; CI 1.5-49.7) was associated with a higher mortality. The increased risk of death was evident for patients with persistently increased levels of uric acid postoperatively (HR = 4.8, 95%; CI = 1.4-16.01).

CONCLUSIONS

Patients undergoing operation for pHPT had a decreased RS during a 10-year follow-up compared to the general population. This decrease in RS is associated with diabetes mellitus and increased levels of uric acid pre-and postoperatively.

Primary hyperparathyroidism, insulin resistance, and cardiovascular disease: a review

The presentation of primary hyperthyroidism (PHPT) has changed substantially in the last decade. Before the introduction of routine calcium measurement in most automated biochemistry serum analyzers, it usually was diagnosed after renal and bony lesions already were present. Nowadays, its presentation is practically asymptomatic. Nevertheless, the cardiovascular morbidity and mortality of mild to moderate forms of PHPT reportedly are increasing. Individuals who have mild to moderate forms of PHPT have an increased risk for enduring cardiovascular disease, arterial hypertension, left ventricular hypertrophy, myocardial and valvular calcifications, altered vascular reactivity, and cardiac conduction. Finally, they also reveal alterations in carbohydrate metabolism, insulin resistance, dyslipidemia, and body composition.

National survey on the management of primary hyperparathyroidism by Swiss endocrinologists

BACKGROUND

From the endocrine surgeon's perspective, it is important to know how endocrinologists manage patients with primary hyperparathyroidism (pHPT). The aim of this survey was to evaluate the preoperative diagnostic workup and referral pattern for parathyroidectomy by Swiss endocrinologists.

MATERIALS AND METHODS

The survey was conducted by mailing a questionnaire to all members of the Swiss Society for Endocrinology and Diabetes in spring 2005.

RESULTS

The questionnaire was sent back by 68 of 124 endocrinologists (55%). The median annual case volume of patients with pHPT was 6 (range 1-50). The mean fraction of these patients referred for surgery was 59 +/- 24%. This fraction was significantly higher in the German-speaking part of Switzerland than in the French-speaking part (67 +/- 21% vs 51 +/- 27%). When considering surgery for asymptomatic pHPT, 62% of the endocrinologists rely routinely on the recommendations of the NIH consensus conference and 86% on the subsequent guidelines of the workshop in 2002. Sixty-seven percent of the endocrinologists routinely perform localization studies before possible referral for surgical exploration. Typically, they consisted of an ultrasonography of the neck (93%) and a (99m)Tc-MIBI scintigraphy (80%). The impact of the availability of a minimally invasive surgical procedure on the number of patients referred for surgery seems to be considerable. Sixty-one percent of the participants would expand the indication for surgery if the operation could be done by a limited surgical approach.

CONCLUSIONS

In a relevant fraction of patients with pHPT, endocrinologists still do not regard curative therapy as mandatory. Surprisingly, there are significant cultural differences concerning referral patterns to surgery between the German-speaking and the French-speaking parts of Switzerland. Minimally invasive procedures seem to lower the threshold for referral for surgical therapy.

Circulating leptin and adiponectin levels in patients with primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) has been associated with high cardiovascular morbidity and mortality; its pathogenesis is not fully understood. Moreover, many metabolic abnormalities are frequently present in patients with PHPT. Several substances (such as leptin and adiponectin) are secreted from adipocytes, which may contribute to regulate energy homeostasis and the development of cardiovascular diseases. We examined the relationship between leptin and adiponectin levels and metabolic disorders in 67 newly diagnosed never-treated patients with PHPT and in 46 healthy subjects (HS). Twenty (29.8%) patients with PHPT presented a metabolic syndrome (as defined by Adult Treatment Panel III criteria). Serum leptin and adiponectin levels in HS were 6.28 +/- 3.3 ng/mL (range, 1.7-19.2 ng/mL) and 6.65 +/- 1.7 microg/mL (range, 3.72-10.86 microg/mL), respectively. In all patients with PHPT, the mean leptin levels (34.28 +/- 20.4 ng/mL) were significantly higher than those of HS (P < .01) and, in particular, in PHPT patients with metabolic syndrome (52.63 +/- 31.2 ng/mL) and positively correlated with body mass index, waist circumference, and cholesterol. The mean adiponectin level was significantly lower (4.34 +/- 3.5 mug/mL) only in PHPT patients with metabolic syndrome (P < .005) and negatively correlated with waist circumference and fasting glucose. We concluded that increased serum level of leptin and decreased serum level of adiponectin coexist in patients with PHPT and may represent a pathogenetic factor for cardiovascular disease in this condition.

Serum ionised calcium and cardiovascular disease in 45-years old men and women followed for 18 years

High level of total serum calcium within the normal range has been associated with increased cardiovascular risk. We wanted to evaluate whether the physiological active ionised form of calcium also was a risk factor for cardiovascular disease (CVD).

METHODS

A total of 974 participants from a health survey in 1981 in Copenhagen had ionised serum calcium and different cardiovascular risk factors measured. The participants were followed until 1999 in The National Hospital Patients Registry and The National Death Registry in Denmark regarding the diagnosis ischemic heart disease (IHD) and a broader definition of CVD. Persons with ionised serum calcium in the highest quintile were compared with persons in the lower four quintiles.

RESULTS

In a univariate analysis persons with ionised serum calcium in the highest quintile had increased risk of IHD (p=0.001) and CVD (p=0.02) compared to persons in the lower quintiles. The increased risk disappeared when gender and cardiovascular confounders were included in a Cox proportional hazards analysis (p=0.20 for IHD and p=0.50 for CVD, respectively). In a separate analysis of men and IHD the result remained insignificant (p=0.07).

CONCLUSIONS

Serum ionised calcium in the upper quintile in women and men together did not seem to be a risk factor in development of IHD and CVD, but a non-significant tendency towards increased risk of IHD was observed in men with ionised calcium in the upper quintile compared to men in the lower four quintiles.

Calcium, Calcium Regulatory Hormones, and Calcimimetics: Impact on Cardiovascular Mortality

Calcemia is a risk factor for cardiovascular (CV) events in dialyzed patients. The relation between serum calcium and cardiovascular events is continuous and linear. Calcium plays a potent role in the genesis of cardiovascular dysfunction, particularly by promoting vascular calcification. Parathyroid hormone (PTH) also is associated with increased CV risk in both primary and secondary hyperparathyroidism. There is a nonlinear relationship between PTH and CV risk; both high and low PTH concentrations increase CV risk. The CV risk profile (BP, dyslipidemia) is strikingly ameliorated by the administration of calcimimetics. Apart from lowering PTH, whether calcimimetics have intrinsic effects on CV risk profile is unknown.

Positive effect of parathyroidectomy on bone mineral density in mild asymptomatic primary hyperparathyroidism

OBJECTIVES

Patients with mild primary hyperparathyroidism (pHPT) often appear asymptomatic, and have previously been regarded as not requiring treatment. However, increased cardiovascular morbidity and dyslipidaemia have also been recognized in mild pHPT, which also seem to be normalized after parathyroidectomy. The present study explores whether postmenopausal women with mild pHPT have decreased bone mineral density (BMD) compared with age-matched healthy controls, and the effects on BMD of parathyroidectomy.

DESIGN, SUBJECTS AND INTERVENTION

A population-based health screening of 5202 postmenopausal women identified 87 overtly asymptomatic patients with mild pHPT as well as age-matched healthy controls. A 5-year follow-up included 49 cases who had undergone parathyroidectomy. BMD was measured with DXA at the femoral neck, the lumbar spine and the total body.

RESULTS

At study entry, BMD was 5-6% lower in the lumbar spine (L2-L4) and femoral neck in cases compared with matched controls. After the 5-year follow-up, BMD increased in L2-L4 by 2.9% (P = 0.002) in the parathyroidectomized cases and remained stable in the femoral neck. However, femoral neck BMD increased 4.1% (P = 0.013) for cases <67 years old (50% of the cohort).

CONCLUSION

In accordance with recent NIH guidelines for pHPT treatment, the level of BMD per se in the investigated group of patients justifies parathyroidectomy in almost half of the cases with mild pHPT. Surgery could be expected to increase BMD in L2-L4 to the level of the controls, to increase femoral neck BMD in patients <67 years of age and to preserve femoral neck BMD in the elderly population.

Increased plasma N-terminal pro-B-type natriuretic peptide and markers of inflammation related to atherosclerosis in patients with primary hyperparathyroidism

OBJECTIVE

Increased risk of cardiovascular disease has been reported in patients with primary hyperparathyroidism (PHPT). The aim of this study was to evaluate novel plasma risk markers of cardiovascular disease in patients with PHPT.

DESIGN

PHPT patients were evaluated with a control group. Patients who underwent parathyroidectomy were re-evaluated after 7 and 18 months.

PATIENTS

Forty-five PHPT patients and 40 matched controls participated. Seventeen patients underwent parathyroidectomy.

MEASUREMENTS

Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha), lipids and blood pressure were measured. In 27 patients a bicycle exercise test and radionuclide angiography were performed, and repeated in those who underwent parathyroidectomy.

RESULTS

Plasma NT-proBNP, CRP and TNF-alpha, but not IL-6, were higher in patients with PHPT than in controls (P < 0.01 and P = 0.17, respectively). In patients with PHPT, NT-proBNP correlated with systolic blood pressure, left ventricular end-diastolic volume, and peak oxygen uptake (all P < 0.01). Log CRP correlated with systolic and diastolic blood pressure (both P < 0.05) and log IL-6 (P < 0.01). No significant correlations were observed between PTH or calcium and risk markers of cardiovascular disease. No decrease in NT-proBNP, markers of inflammation or blood pressure was observed after parathyroidectomy.

CONCLUSIONS

Our data suggest that hypertension or other factors, rather than plasma calcium or PTH, could explain the increased levels of the inflammatory markers and NT-proBNP in PHPT. We therefore suggest that aggressive treatment of hypertension should be initiated in patients with PHPT to try to reduce the increased cardiovascular mortality described in PHPT. Further prospective studies are needed to validate the suggestion that increased levels of NT-proBNP and inflammatory markers also represent strong prognostic markers of cardiovascular disease in patients with PHPT.

Impact of parathyroidectomy on renal graft function, blood pressure and serum lipids in kidney transplant recipients: a single centre study

BACKGROUND

Successful kidney transplantation is believed to reverse secondary hyperparathyroidism, but persistent disease has emerged in a significant number of allograft recipients. Parathyroid hormone (PTH) is not only involved in the aetiology of calcium/phosphate abnormalities and osteitis fibrosa, but it is also a permissive factor in the occurrence of hypertension, cardiovascular damage and dyslipidaemia. In experimental renal failure, abrogation of hyperparathyroidism by administration of a calcimimetic or parathyroidectomy (PTX) attenuates progression of renal failure. To evaluate the impact of PTX on blood pressure (BP), renal graft function and serum lipids, we performed a retrospective case-controlled study in renal graft recipients.

METHODS

Charts of 1647 kidney allograft recipients, transplanted between 1989 and 2004, were reviewed. Thirty-two patients with a functioning graft and a history of a successful PTX performed at least 9 months after transplantation were identified. Biochemical and clinical data available 6 months pre- and post-PTX were registered. Changes in BP, renal function and serum lipids were assessed. The data were compared with those obtained in a similar time frame in a control group closely matched for date of transplantation.

RESULTS

Systolic BP (149.9 vs 141.7 mmHg), diastolic BP (85.6 vs 81.9 mmHg), pulse pressure (64.3 vs 58.8 mmHg), total cholesterol concentration (221.4 vs 211.1 mg/dl) and low-density lipoprotein cholesterol concentration (123.9 vs 106.7 mg/dl) improved significantly after successful PTX. Serum creatinine, conversely, significantly increased after PTX (1.75 vs 2.13 mg/dl, P<0.0001). No significant changes were observed in the control group in the same time period.

CONCLUSION

In patients with a functioning renal graft, BP and dyslipidaemia improve, whereas serum creatinine worsens following successful PTX. Our data are in agreement with a stimulatory effect of PTH on plasma renin activity and an inhibitory effect on lipase activity, as previously demonstrated by others. To what extent the increased serum creatinine following PTX reflects a true deterioration of the glomerular filtration rate and/or is the consequence of vitamin D-induced reduction of the renal tubular secretion of creatinine needs to be elucidated by further research.

Primary hyperparathyroidism. Update on pathophysiology, clinical presentation and surgical treatment

The most important step in calcium homeostasis is the regulation of parathyroid hormone (PTH) secretion. The discovery and characterization of the calcium sensing receptor (CaR) of the parathyroid cell has led to a better understanding not only of the physiology of the parathyroid glands, but also of the development of hyperparathyroidism. Drugs acting on CaR can now be designed to treat hyperparathyroidism and osteoporosis. The workshop on primary hyperparathyroidism held at the National Institutes of Health in 2002 has recommended new guidelines for the treatment of asymptomatic hyperparathyroidism. Controversy still exists regarding the treatment of patients with non-classical symptoms, such as weakness, fatigue and depression. Primary hyperparathyroidism as a risk factor for cardiovascular disease and mortality is also debated. Improved techniques for the preoperative localization of pathological parathyroid glands have led to a shift in surgical strategy: surgeons abandon the traditional bilateral neck exploration in favor of a more limited approach. This change of strategy has not been based on the results of prospective randomized studies and the long term results are not known.

Mortality in sporadic primary hyperparathyroidism: nationwide cohort study of multiple parathyroid gland disease

BACKGROUND

The risk of dying from primary hyperparathyroidism (pHPT) is controversial and has been explored mainly in single parathyroid gland disease. The present study investigates mortality in pHPT due to multiple parathyroid gland disease.

METHODS

We used the nationwide Swedish In-patient Register and Cause-of-Death Registry to compare the mortality in 3485 Swedish patients subjected to parathyroidectomy during 1964 to 1999 with that of the Swedish population (standardized for age, gender, and calendar year). The patient cohort includes 36,596 person years.

RESULTS

Increased risk of death beyond the first postoperative year (standardized mortality ratio, 1.4; 95% CI, 1.37-1.52) was found in both sexes and for all age intervals below 80 years. The increased risk persisted more than 15 years postoperatively and related to cardiovascular diseases, diabetes mellitus, urogenital diseases, and malignant disorders. The increased risk of dying in cardiovascular diseases normalized during 1990 to 1999.

CONCLUSIONS

pHPT caused by multiple parathyroid gland enlargement is associated with an excessive mortality similar to pHPT of single parathyroid adenoma. The findings substantiate that modern modes of surgical treatment for pHPT normalize the risk of dying from cardiovascular complications and that the hyperpararthyroid state per se is the possible cause of the premature death.

Association between primary hyperparathyroidism and increased body weight: a meta-analysis

Although primary hyperparathyroidism is frequently asymptomatic, it has been associated with an increased prevalence of hypertension, insulin resistance, dyslipidemia, cardiovascular mortality, and cancer. Previously we reported that patients with primary hyperparathyroidism are heavier than age-matched controls. Increased body weight could contribute to the association between primary hyperparathyroidism and these extraskeletal complications. We searched MEDLINE for English language studies published between 1975 and 2003 that reported body weight or body mass index in subjects with primary hyperparathyroidism and a healthy age- and sex-comparable eucalcemic control group. Seventeen eligible studies were identified. Subjects with primary hyperparathyroidism were 3.34 kg (95% confidence interval, 1.97-4.71; P < 0.00001) heavier than controls in 13 studies reporting body weight. In four studies reporting body mass index, subjects with primary hyperparathyroidism had an increased body mass index of 1.13 kg/m(2) (-0.29 to 2.55; P = 0.12) compared with controls. Standard mean difference analysis showed that subjects with primary hyperparathyroidism had an increased weight or body mass index of 0.3 sd (0.19-0.40; P < 0.00001) compared with controls. We conclude that patients with primary hyperparathyroidism are heavier than their eucalcemic peers, and that increased body weight may contribute to the reported associations between primary hyperparathyroidism and some extraskeletal complications.

Increased mortality in patients hospitalized with primary hyperparathyroidism during the period 1977-1993 in Denmark

The aim of the present study was to determine whether patients with the incident hospital diagnosis of primary hyperparathyroidism (PHPT) in Denmark during the period 1977-1993 had an increased mortality from cardiovascular disease and cancer compared to the rest of the Danish population. In a random sample of half of the Danish population, all patients with an incident hospital diagnosis of PHPT were identified in the National Hospital Patients Register. The mortality in the cohort was analyzed and compared with the background population. A cohort of 1578 patients was identified. Follow-up of 1179 women and 376 men, who did not die in the same month as the incident PHPT diagnosis, was made through 1993. Of these, 312 (20%) died within the follow-up period. The standard mortality ratio (SMR) for women was 1.7 (95% confidence interval [95% CI]: 1.5-1.9). SMR for men was 1.6 (95% CI: 1.3-2.0). In women an increased mortality from ischemic heart disease, cerebrovascular disease, and cancer was found. In men an increased mortality from cerebrovascular disease and cancer was found.

Derangement of glucose metabolism in hyperparathyroidism

The derangement of glucose metabolism is found frequently in all forms of hyperparathyroidism. Both in primary (PHPT) and secondary hyperparathyroidism (SHPT) PTH excess is thought to be involved in deteriorating insulin sensitivity and secretion though their different clinical and pathophysiological conditions. In PHPT these abnormalities are related to a high frequency of Type 2 diabetes mellitus and also impaired glucose tolerance according to recent clinical studies, without differences between symptomatic and asymptomatic clinical presentation. In chronic renal failure (CRF), the disorders of glucose metabolism due to SHPT do not bear an increased risk for diabetes whereas they seem to be involved in the progression of atherosclerotic vascular damage which connotes CRF. Moreover, clinical and experimental studies have shown that vitamin D deficiency associated with glucose metabolism abnormalities favors the development of the metabolic syndrome. The potential for metabolic and cardiovascular harm related to hyperparathyroidism, especially PHPT, is the most interesting issue for clinical endocrinologists. This short review of the clinical and pathophysiological data of literature on glucose homeostasis disorders in hyperparathyroidism focuses on its potential clinical and therapeutic impact, particularly in the management of PHPT.

Cardiovascular disease, hypertension and renal function in primary hyperparathyroidism

OBJECTIVES

Patients with primary hyperparathyroidism run an increased risk of death in cardiovascular disease. Long ago, hypertension was found to frequently occur in these patients. The aim of this study was to compare the death risk after surgery for hyperparathyroidism of hypertensive patients with that of normotensive ones, and to investigate relations between variables of cardiovascular disease and variables of hyperparathyroidism and renal function.

METHODS

A series of 845 patients with primary hyperparathyroidism and serum creatinine <or=160 micromol L-1 was followed-up mean 10.2 (SD 5.7) years after surgery. Survival and correlation tests were performed. Death risk was estimated using a hazard function according to Poisson.

RESULTS

The death risk of hypertensive hyperparathyroid patients was 50% higher compared with that of the normotensive patients, but the yearly death risk decrease after surgery for the hypertensive patients was almost doubled as compared with the decrease of the normotensive patients. Cardiovascular disease was directly related to serum calcium level, adenoma weight, osteitis fibrosa, and serum creatinine, and inversely related to glomerular filtration rate and urine osmolality, but unrelated to the symptom variables. A negative relation was found between cardiovascular disease and renal stone disease.

CONCLUSIONS

It can be concluded that cardiovascular disease is more a part of primary hyperparathyroidism than just associated with it, being related to both serum calcium and adenoma weight. There was also a relationship between cardiovascular disease and decreased renal function. Death risk decrease after surgery was rather more pronounced for the hypertensive patients compared with the normotensive ones.