Biochemical effects of calcifediol supplementation in mild, asymptomatic, hyperparathyroidism with concomitant vitamin D deficiency

Vitamin D supplementation in primary hyperparathyroidism: effects on 1,25(OH)2 vitamin D and FGF23 levels

PURPOSE

In patients with Primary Hyperparathyroidism (PHPT) vitamin D deficiency has been associated with more severe presentations. Our aim was to investigate the effects of Vitamin D supplementation on mineral homeostasis and related hormones in individuals with and without PHPT.

METHODS

Individuals with and without PHPT (CTRL) received 14,000 IU/week of oral vitamin D3 for 12 weeks. At baseline and endpoint, blood samples were collected to measure 1,25(OH)2vitamin D (1,25(OH)2D), intact Fibroblast Growth Factor 23 (FGF23), 25OHD, Parathormone, and other biochemical markers. The 1,25(OH)2D measurement was performed using liquid chromatography and mass spectrometry (LC-MS/MS).

RESULTS

70 PHPT patients and 75 CTRL were included, and 55 PHPT and 64 CTRL completed the 12-week protocol. After the intervention, there were significant increases in the FGF23 levels (PHPT: 47.9 ± 27.1 to 76.3 ± 33.3; CTRL: 40.5 ± 13.9 to 59.8 ± 19.8 pg/mL, p < 0.001), and significant decreases in 1,25(OH)2D levels (PHPT: 94.8 ± 34.6 to 68.9 ± 25.3; CTRL: 68.7 ± 23.5 to 56.4 ± 20.7 pg/mL, p < 0.001). The reduction of 1,25(OH)2D was inversely associated with the increase of FGF23 in both the PHPT (r = -0.302, p = 0.028) and CTRL (r = -0.278, p = 0.027). No changes in plasmatic or uninary calcium concentrations were observed in both groups.

CONCLUSION

The weekly administration of 14,000 IU of Vitamin D3 was safe and efficient to increase in 25OHD levels in both groups. However, a paradoxical decrease in 1,25(OH)2D levels measured by LC-MS/MS was associated with a significant increase in FGF23 levels in both groups. This phenomenon might represent a defense against hypercalcemia after vitamin D supplementation and paves the way for new studies in this regard.

Vitamin D Deficiency and the Presentation of Primary Hyperparathyroidism: A Mini Review

The clinical presentation of primary hyperparathyroidism (PHPT) has evolved over the years from a symptomatic disorder to a predominantly asymptomatic condition. Altered vitamin D metabolism seems to play a role in the presentation of PHPT and may exacerbate the severity of disease. The epidemiology of PHPT differs in the developing versus the developed world, where more severe phenotypes occur in regions where vitamin D deficiency is common. Although it has been validated that patients with PHPT should be vitamin D sufficient, the threshold to supplement in relation to the severity of PHPT and the degree of vitamin D deficiency remains controversial. This review will highlight some of the controversy regarding vitamin D deficiency and the different phenotypes of PHPT.

Safety and efficacy of common vitamin D supplementation in primary hyperparathyroidism and coexistent vitamin D deficiency and insufficiency: a systematic review and meta-analysis

PURPOSE

Primary hyperparathyroidism (PHPT) is characterized by excessive secretion of parathyroid hormone (PTH). Vitamin D deficiency can stimulate parathyroid secretion. However, whether to correct vitamin D deficiency in patients with PHPT is controversial. We aimed to evaluate the safety and efficacy of vitamin D replacement in patients with PHPT.

METHODS

We searched PubMed, Cochrane Library, and Embase. The relevant data were extracted from the included documents. The methodological items for non-randomized studies score entries were used for evaluation of quality. Review Manager 5.3 and Stata 12.0 were used for statistical analysis.

RESULTS

A total of 11 articles were included with a total of 388 patients. The serum calcium mean difference (MD) was - 0.06 mg/dL [95% confidence interval (95% CI) - 0.16, 0.04]. Subgroup analysis showed that serum calcium levels did not change if the intervention time exceeded 1 month. The 24-h urinary calcium MD was 36.78 mg/day (95% CI - 37.15, 110.71), which indicated that there was no significant effect of vitamin D supplementation on 24-h urinary calcium levels. The MD of PTH was - 16.01 pg/mL (95% CI - 28.79, - 3.24). Subgroup analysis according to the intervention time showed that vitamin D intervention for more than 1 month significantly reduced PTH levels. The ALP MD was - 10.81 U/L (95% CI - 13.98, - 7.63), which indicated Vitamin D supplementation reduced its level. The MD of 25-hydroxyvitamin D was 22.09 μg/L (95% CI 15.01, 29.17), and no source of heterogeneity was found.

CONCLUSION

Vitamin D supplementation in patients with PHPT and vitamin D deficiency significantly reduces PTH and ALP levels without causing hypercalcemia and hypercalciuria.

Serum Vitamin D Level Does not Affect The Sensitivity of Parathyroid Adenoma Localization Tests

The aim of the present study was to evaluate the predictive value of 25-hydroxyvitamin D, calcium and parathormone level, co-existence of thyroid nodule, thyroidectomy history and adenoma volume on the success of neck ultrasound (US) and technetium-99m sestamibi (MIBI) scan in primary hyperparathyroidism (PHP) patients. This study included 256 patients with PHP who underwent parathyroidectomy. 169 (%66) patients had vitamin D deficiency and 56 (%22) of patients had insufficiency. The sensitivity of US and MIBI studies showed no difference between vitamin D deficiency, insufficiency and replete groups (%80.5, %82 and %71 (p > 0.05) and %81, %84 and %71 respectively (p > 0.05)). Vitamin D level was not found to be an independent predictor of localization on either US or MIBI scan after adjusting for different variables (p > 0.05). Calcium level was found to be an independent predictor for US sensitivity (r²:0,033, p:0,032) and parathormone level for MIBI sensitivity (r²:0,05, p:0,025). The co-existence of nodular thyroid disease and history of thyroidectomy significantly decreased the sensitivity of US (%76 and %43). MIBI sensitivity was not impaired by nodular disease but the history of thyroidectomy also impaired the sensitivity of MIBI (%43). As a result vitamin D level does not affect the sensitivity of preoperative localization tests.

The impact of vitamin D status and parameters of calcium metabolism in patients with primary hyperparathyroidism

BACKGROUND

There is ample evidence associating vitamin D deficiency in primary hyperparathyroidism (PHP) patients with more severe disease manifestations and increased risk of postoperative hypocalcemia. Yet, there is limited data regarding the safety of vitamin D repletion in these patients.

AIM

To assess the safety of vitamin D repletion in PHP patients in a real-world setting.

DESIGN

We included patients with asymptomatic PHP and few symptomatic patients who declined surgery, followed in our clinic, and treated on a routine basis with 2000 IU/day of vitamin D3.

METHODS

Serum calcium (sCa), PTH, 25-hydroxyvitamin D, and 24 h urinary calcium (uCa) and creatinine collections were compared between the lowest and the highest vitamin D time points.

RESULTS

There were 40 patients of a mean age was 63 ± 10 years. 25(OH)D at lowest and highest vitamin D time points was 15.5 ± 6.2 ng/ml and 33.2 ± 8, respectively (P < 0.001). Serum calcium was not affected by the changes in vitamin D levels. In none of the patients did sCa exceed 11.5 mg/dL. uCa was 220 ± 110 mg/24 h at the lowest vitamin D time point and 260 ± 140 at the highest vitamin D time point (P = 0.14). uCa exceeded 400 mg/24 h in two vs. five patients (P = 0.23) at the lowest and highest vitamin D time points, respectively. PTH was not significantly different between the different vitamin D time points.

DISCUSSION/CONCLUSION

Vitamin D repletion in PHP seems safe. Considering the documented adverse influence of vitamin D deficiency in PHP, particularly on skeletal manifestations and on the postoperative course, vitamin D repletion is warranted.

The surgical management of primary hyperparathyroidism: an updated review

Patients with primary hyperparathyroidism often present clinically asymptomatic with various biochemical compositions of serum calcium, parathyroid hormone, vitamin D and urinary calcium. Understanding the subtle differences in clinical and biochemical presentations is key for timely diagnosis and referral to an experienced parathyroid surgeon. Surgery remains the only option for cure of primary hyperparathyroidism, which now favors a directed parathyroidectomy with intra-operative adjuncts. However it is important to understand and revise the surgical approach for patients with hereditary conditions or nonlocalizing studies. Revised guidelines from the Fourth International Workshop on the Management of Asymptomatic Primary Hyperparathyroidism in 2013 and the American Association of Endocrine Surgeons in 2016 are reviewed in this paper for an updated review of this condition.

Impact of vitamin D deficiency on the clinical and biochemical phenotype in women with sporadic primary hyperparathyroidism

The purpose of the study was to evaluate the relationship between serum 25(OH)D and the clinical phenotype in 215 consecutive Italian Caucasian women with sporadic primary hyperparathyroidism (PHPT) not taking vitamin D supplements. The study was performed at a single Italian tertiary center. PHPT-related manifestations, serum 25(OH)D, and other parameters of calcium metabolism and bone mineral density (BMD) by DXA were recorded. Serum 25(OH)D was negatively correlated with age (r = -0.18; P = 0.006), BMI (r = -0.20; P = 0.002), PTH (r = -0.21; P = 0.001), bone-specific alkaline phosphatase (BSAP) (r = -0.27; P < 0.001), and eGFR (r = -0.22; P = 0.01), and positively with serum creatinine and 1/3 distal radius BMD (R-BMD; r = 0.17; P = 0.015). In a multivariate regression analysis, serum 25(OH)D remained significantly correlated with age (r = -0.18; P = 0.005), BMI (r = -0.23; P = 0.049), serum PTH (r = -0.01; P = 0.023), BSAP (r = -0.01; P = 0.023) and eGFR (r = -0.09; P = 0.001), but not with R-BMD. Serum 25(OHD) was higher in patients with nephrolithiasis than in those without nephrolithiasis (18.5 ± 8.8 vs. 15.6 ± 8.0 ng/ml; P = 0.029), whereas no difference was found between fractured and unfractured patients (16.8 ± 9.3 vs. 16.0 ± 7.7; P = 0.663). There was a statistically significant inverse correlation between vitamin D status [defined by quartiles of measured values as well as commonly accepted cutoffs of serum 25(OH)D] and severity of the disease, as reflected by higher PTH and BSAP, but not by meeting the latest guidelines for parathyroidectomy. In conclusion, a low vitamin D status is associated with some features reflecting a more severe biochemical and clinical phenotype of PHPT in Italian women not taking vitamin D supplements.

MECHANISMS IN ENDOCRINOLOGY: Kidney involvement in patients with primary hyperparathyroidism: an update on clinical and molecular aspects

Primary hyperparathyroidism (PHPT) is the third most common endocrine disease. Kidney is a target of both chronic elevated PTH and calcium in PHPT. The classic PHPT complications of symptomatic kidney stones and nephrocalcinosis have become rare and the PHPT current presentation is asymptomatic with uncertain and long-lasting progression. Nonetheless, the routine use of imaging and of biochemical determinations have revealed the frequent occurrence of asymptomatic kidney stones, hypercalciuria and reduced kidney function in asymptomatic PHPT patients. Though the pathogenesis is far from being elucidated, PHPT is associated with reduced renal function, in terms of estimated glomerular filtration rate, and related increased morbidity and mortality. In the last decade, the effort of the Kidney Disease: Improving Global Outcomes (KDIGO) panel of experts highlighted that even mild reduction of kidney function is associated with increased risk of cardiovascular disease. These considerations provided the basis for the Fourth Workshop recommendations of a more extensive diagnostic workout about kidney features and of wider criteria for parathyroid surgery including asymptomatic kidney disease. Moreover, kidney involvement in PHPT is likely to be affected by variants of genes coding the key molecules regulating the calcium and ions renal handling; these features might have clinical relevance and should be considered both during diagnostic workout and follow-up. Finally, the effects of parathyroid surgery and of medical treatment on kidney involvement of PHPT are reviewed.

Primary Hyperparathyroidism

Over the past several generations, primary hyperparathyroidism (PHTP) has undergone a change in its clinical presentation in many countries from a symptomatic disease to an asymptomatic one. The reasons for this change in clinical presentation are related to the widespread use of biochemical screening tests, to the measurement of PTH more routinely in the evaluation of metabolic bone disease and to the status of vitamin D sufficiency in the population. Along with recognition of a broader clinical spectrum of disease, including a more recently recognized normocalcemic variant, has come an appreciation that the evaluation of classic target organs that can be affected in PHPT, such as the skeleton and the kidneys, require more advanced imaging technology for complete evaluation. It is clear that even in asymptomatic patients, evidence for microstructural disease in the skeleton and calcifications in the kidneys can be demonstrated often. Potential non-classical manifestations of PHPT related to neurocognition and the cardiovascular system continue to be of interest. As a result of these advances, revised guidelines for the management of asymptomatic PHPT have been recently published to help the clinician determine whether surgery is appropriate or whether a more conservative approach is acceptable.

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.

Effects of alendronate and vitamin D in patients with normocalcemic primary hyperparathyroidism

No data on the pharmacological treatment of normocalcemic hyperparathyroidism (NPHPT) are available. We treated 30 NPHPT postmenopausal women with alendronate/cholecalciferol (treated group) or vitamin D alone (control group). Over 1 year, bone mineral density (BMD) increased significantly in treated group, but not in control group. Both treatments did not affect serum or urinary calcium.

INTRODUCTION

Normocalcemic primary hyperparathyroidism (NPHPT) is defined by normal serum calcium and consistently elevated PTH levels after ruling out the causes of secondary hyperparathyroidism. It is likely that subjects with NPHPT may develop kidney and bone disease. As no data on the pharmacological treatment of NPHPT are available, we aimed to investigate the effects of alendronate and cholecalciferol on both BMD and bone biochemical markers in postmenopausal women with NPHPT. Safety of vitamin D was evaluated as secondary endpoint.

METHODS

The study was a prospective open label randomized trial comparing 15 postmenopausal women with NPHPT (PMW-NPHPT), treated with oral alendronate plus cholecalciferol (treated group) and 15 PMW-NPHPT treated only with cholecalciferol (control group). Blood samples were obtained at baseline and after 3, 6, and 12 months. Bone turnover markers (BTM) were measured at baseline, 3, and 6 months, respectively. BMD was assessed at baseline and after 12 months.

RESULTS

After 1 year of treatment, BMD increased significantly at the lumbar, femoral neck, and hip level in the treated group, but not in the control group (p = 0.001). No differences were found between or within groups in serum calcium, PTH, and urinary calcium levels. BTM significantly decreased in the treated group but not in the control group, at 3 and 6 months (p < 0.001), respectively. No cases of hypercalcemia or hypercalciuria were detected during the study.

CONCLUSION

The results of this study indicate that alendronate/cholecalciferol increases BMD in postmenopausal women with NPHPT. Alendronate/cholecalciferol or vitamin D alone does not affect serum or urinary calcium.

Impact of vitamin D replacement in patients with normocalcaemic and hypercalcaemic primary hyperparathyroidism and coexisting vitamin D deficiency

Background

Vitamin D deficiency is increasingly recognized in patients with primary hyperparathyroidism but some clinicians are reluctant to replace vitamin D due to concerns with aggravating hypercalcaemia. We investigated the impact of vitamin D repletion in asymptomatic patients with normocalcaemic and hypercalcaemic primary hyperparathyroidism.

Methods

This is a retrospective analysis of 111 patients with elevated parathyroid hormone concentrations (>6.4 pmol/L) referred to our endocrine clinic between January and December 2012; we identified 39 patients with primary hyperparathyroidism and vitamin D deficiency, i.e. 25 hydroxy vitamin D <20  µg/L. Patients were categorized into normocalcaemic (n = 23) and hypercalcaemic (n = 16) groups and the impact on biochemical parameters was recorded after at least six months treatment with either 1600 or 3200 units daily of cholecalciferol.

Results

Both normocalcaemic and hypercalcaemic groups showed a rise in 25 hydroxy vitamin D concentrations after replacement (p <0.0001). Parathyroid hormone concentrations fell in the normocalcaemic group (p = 0.08) but individually, five patients showed a rise (8–38% of baseline). In the hypercalcaemic group, parathyroid hormone remained static but the adjusted calcium concentration fell significantly (p = 0.006) except in two patients who showed mild rises (3 and 6%, respectively). There was no deterioration in renal function or calcium-related adverse events in any of the groups.

Conclusions

Our study supports the safety of vitamin D replacement in patients with mild asymptomatic primary hyperparathyroidism and coexistent vitamin D deficiency. Repletion does not aggravate hypercalcaemia and may limit disease progression. Patients with normocalcaemic primary hyperparathyroidism need further characterization from longitudinal studies.

Effects of high doses of cholecalciferol in normal subjects: a randomized double-blinded, placebo-controlled trial

BACKGROUND

Vitamin D repletion with high doses of vitamin D is often recommended to patients and healthy subjects. The safety, especially concerning changes in urinary calcium excretion is of great importance.

METHODS

In a double-blinded, placebo-controlled study in 40 healthy volunteers, we examined the changes in mineral metabolism during supplementation with 3000 IU of oral cholecalciferol daily during 4 months.

RESULTS

Both 25(OH)vitamin D and 1,25(OH)2vitamin D increased significantly in the active treated group as compared to the placebo group (186% versus 14% (P<0.001) and 28% versus -8% (P<0.001)). No change was observed in urinary calcium excretion in the active group compared to the placebo group (P = 0.891). Fibroblast growth factor 23 increased significantly by 10% (P<0.018) in the active group. However, there was no difference in changes in FGF23 between treatment groups (P = 0.457).

CONCLUSION

High dose cholecalciferol significantly increases 25(OH)vitamin D and 1,25(OH)2vitamin D levels compared to placebo. No changes in urinary calcium excretion or other measured components of the mineral metabolism were found between groups.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00952562.

Effect of 25 (OH) D replacements in patients with primary hyperparathyroidism (PHPT) and coexistent vitamin D deficiency on serum 25(OH) D, calcium and PTH levels: a meta-analysis and review of literature

CONTEXT

The safety of vitamin D replacement in subjects with primary hyperparathyroidism (PHPT) and coexistent vitamin D deficiency is not well established.

OBJECTIVE

To evaluate the safety of vitamin D replacement in PHPT.

DATA SOURCE

Data were searched from Medline, EMBASE, Cochrane CENTRAL and abstracts form annual scientific meetings of various international bone and mineral societies.

STUDY SELECTION

Studies examining the effect of preoperative vitamin D replacement in patients with PHPT and coexisting vitamin D deficiency, irrespective of year and language of the publication were included in the present meta-analysis.

DATA EXTRACTION

Data were extracted from text of the included publications or abstract of conferences.

DATA SYNTHESIS

Ten studies enrolling 340 subjects with PHPT were analysed in this meta-analysis. After vitamin D replacement, there was significant increase in 25(OH) D levels by 55·3 nmol/l (95% CI 33·3-77·3), reduction in serum parathyroid hormone levels by 3·5 pmol/l (5·8 to -1·2) without change in serum calcium (-0·08 mmol/l, -0·2 to +0·03) and urinary calcium levels (0·72 mmol/24 h, P = 0·2) compared to baseline.

CONCLUSION

Vitamin D replacement in subjects with PHPT and coexistent vitamin D deficiency increase 25 (OH) D and reduce serum PTH significantly without causing hypercalcaemia and hypercalciuria. The finding of the study needs to be confirmed by a large randomized trial in patient with PHPT and coexistent vitamin D deficiency.

Management of hypovitaminosis D in patients with primary hyperparathyroidism

AIM

Epidemiological studies suggest that vitamin D deficiency is common in patients with primary hyperparathyroidism (PHPT). They have higher levels of serum parathyroid hormone (PTH) and markers of bone turnover and fractures are more frequent than vitamin D-replete patients. However, there are concerns that Vitamin D repletion might exacerbate pre-existent hypercalcaemia. Therefore, we aimed to determine if vitamin D replacement improved biochemical indices of calcium metabolism without worsening underlying hypercalcaemia.

SUBJECTS AND METHODS

This is a prospective, observational study based on routine clinical practice, set up in a secondary care centre. 45 consecutive patients with mild biochemical hypercalcaemia due to PHPT and hypovitaminosis D were enrolled. The mean age of the cohort was 61 years (range 25-85 years), predominately Asian (32 patients) and female (41 patients). They received 20,000 IU of oral cholecalciferol, once a week, for 3 months. Calcium, phosphate, alkaline phosphatase and PTH were measured at baseline, 4, 8 and 12 weeks following treatment. Vitamin D levels were obtained at baseline and at 12 weeks, after they completed their treatment.

RESULTS

Vitamin D levels normalised at week 12 (mean ± SD, 18.8 ± 9.4 versus 76 ± 20 nmol/L, p = 0.0001) and PTH levels improved following treatment completion (21.2 ± 10 versus 16.2 ± 6 pmol/L, p = 0.026). There was no significant increase in serum calcium levels during vitamin D supplementation.

CONCLUSIONS

High doses of oral cholecalciferol normalised vitamin D levels without worsening underlying hypercalcaemia in individuals with PHPT.

Sporadic primary hyperparathyroidism: medical and surgical updates

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

Associations of serum 25-hydroxyvitamin D with circulating PTH, phosphate and calcium in patients with primary hyperparathyroidism

BACKGROUND

Despite NIH clinical recommendations, many clinicians are reluctant to replace vitamin D in patients with hypercalcaemia with primary hyperparathyroidism (PHP) due to concerns over aggravating hypercalcaemia. Furthermore, the optimum level of vitamin D replacement in PHP remains unclear.

METHODS

We performed a large retrospective study to determine whether a relationship exists between serum 25-hydroxyvitamin D levels, calcium and other important biochemical markers in patients with PHP. Serum, plasma and urinary biochemical measurements were collected from 251 patients with hypercalcaemia diagnosed with PHP.

RESULTS

When examining overall mean circulating levels during clinical follow-up, serum 25-hydroxyvitamin D correlated highly significantly with plasma parathyroid hormone (PTH) (r = -0.23, P = 0.0003) and serum phosphate (r = 0.16, P = 0.0119). No significant relationship was observed between serum calcium and 25-hydroxyvitamin D (r = 0.002, P = 0.98). Mean plasma PTH during clinical follow-up was 51% lower in patients with serum 25-hydroxyvitamin D > 60 nm when compared with patients who had 25-hydroxyvitamin D < 20 nm (P < 0.01).

CONCLUSIONS

Patients with PHP who have 25-hydroxyvitamin D levels > 60 nm have significantly reduced PTH hypersecretion when compared with patients with deficient vitamin D levels, without exhibiting worse hypercalcaemia.

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

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

What medical options should be considered for the treatment of primary hyperparathyroidism?

Primary hyperparathyroidism (PHPT) is a common, often asymptomatic, endocrine disorder characterized by hypercalcaemia in the face of a nonsuppressed parathyroid hormone (PTH) level. For those with symptomatic disease or who meet surgical criteria, parathyroidectomy is the treatment of choice. However, those patients who do not meet surgical criteria or who cannot undergo or refuse surgery must be managed medically. Medical management of PHPT involves continual assessment to determine who will benefit from surgical intervention, replacement of vitamin D, treatment of parathyroid bone disease and management of hypercalcaemia and renal stone disease.

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.

An unusual case of hypercalcemia associated with graves' disease and vitamin d deficiency

Objective:

To present a case of hypercalcemia associated with thyrotoxicosis in a patient with vitamin D deficiency and review biochemical changes during the course of treatment.

Methods:

We report a case, describe the changes in serum calcium, phosphorus, parathyroid hormone in Graves’ disease and concomitant Vitamin D deficiency. We compare our findings to those reported in literature.

Results:

Our patient had hypercalcemia secondary to thyrotoxicosis alone, which was confirmed by low parathyroid hormone level and resolution of hypercalcemia with treatment of thyrotoxicosis. The case was complicated by a concomitant vitamin D deficiency. Serum calcium elevation in patients with thyrotoxicosis occurs secondary to hyperthyroidism alone or due to concurrent hyperparathyroidism. Hypercalcemia from thyrotoxicosis is usually asymptomatic and is related to bone resorption. Vitamin D deficiency can be seen in patients with thyrotoxicosis because of accelerated metabolism, poor intestinal absorption and increased demand during bone restoration phase. Coexistence of hypercalcemia and Vitamin D deficiency in patients with thyrotoxicosis is rare, but possible, and 25-hydroxyvitamin D levels should be checked. The definite treatment for hypercalcemia in thyrotoxicosis is correction of thyroid function.

Conclusion:

Hypercalcemia in thyrotoxicosis should be distinguished from concomitant hyperparathyroidism and confirmed by resolution of hypercalcemia with control of thyrotoxicosis. Patients with hypercalcemia and thyrotoxicosis may also have vitamin D deficiency and 25-OH Vitamin D levels should be checked.

Clinical significance of vitamin D deficiency in primary hyperparathyroidism, and safety of vitamin D therapy

Vitamin D deficiency occurs more frequently in patients with primary hyperparathyroidism (PHPT) compared with the general population, and is usually associated with an aggravated form of the disease. Current guidelines recommend measurement of serum levels of 25-hydroxy vitamin D (25-OHD) in all patients with PHPT, and their repletion if the levels are less than 50 mmol/L (20 ng/mL). Limited data suggest that vitamin D treatment is generally safe in subjects with mild PHPT and coexisting vitamin D deficiency. Adverse effects include hypercalcuria and, less commonly, exacerbation of hypercalcemia. Well-designed trials are needed to evaluate the safety of vitamin D replacement therapy in a wide spectrum of patients with concomitant PHPT and vitamin D deficiency. These trials should address the impact of such therapy on the complications and course of PHPT.

Primary hyperparathyroidism: an update

PURPOSE OF REVIEW

Primary hyperparathyroidism (PHPT) is a constantly evolving disease. As more evidence on the cardiovascular and neuropsychiatric manifestations of apparently asymptomatic disease accumulates, and since medical therapeutic options and surgical indications are being further investigated, it is important to review this disease entity to gain a fresh, updated perspective on the current disease phenotype and treatment approach.

RECENT FINDINGS

The pathogenesis of PHPT has not been completely elucidated yet, but some potential culprits, such as gene mutations, growth factors, calcium sensing receptor antibodies, and chronic vitamin D deficiency are being identified. There is increasing evidence that even mild, asymptomatic PHPT is associated with some aspects of cardiovascular and neuropsychiatric dysfunction, but the clinical significance as well as the reversibility with parathyroidectomy of these abnormalities remain to be determined. Medical therapies such as bisphosphonates and calcimimetics are showing some promise in the treatment of PHPT, although surgery remains the only curative intervention. The indications for surgical intervention in patients with asymptomatic PHPT have been recently revised.

SUMMARY

Parathyroidectomy is the treatment of choice for patients with symptomatic PHPT and patients with asymptomatic PHPT who fulfill certain age, bone density, serum calcium, and creatinine criteria. Further research is needed to determine whether patients with prominent cardiovascular and neuropsychiatric manifestations would benefit from such intervention.

Vitamin D and primary hyperparathyroidism (PHPT)

Vitamin D deficiency and PHPT are two common conditions, especially in postmenopausal women. Vitamin D deficiency is said to be even more frequent in PHPT patients than in the general population due to an accelerated conversion of 25OHD into calcitriol or 24-hydroxylated compounds. Although several studies have reported worsening of PHPT phenotype (larger tumours, higher PTH levels, more severe bone disease) when vitamin D deficiency coexists whereas vitamin D supplementation in PHPT patients with a serum calcium level<3 mmol/L has been shown to be safe (no increase in serum or urinary calcium) and to decrease serum PTH concentration, that many physicians are afraid to give vitamin D to already hypercalcemic PHPT patients. On the other hand, it is possible that, in some patients, a persistent vitamin D deficiency induces, in the long-term, an autonomous secretion of PTH (i.e. tertiary hyperparathyroidism). The mechanism by which this could occur is unclear however. Finally, as many, otherwise normal, subjects with vitamin D insufficiency may have an increased serum PTH level we believe that those with vitamin D insufficiency should be excluded from a reference population for serum PTH levels. By doing that, we found that the upper normal limit for serum PTH was 25-30% lower than in the whole population.