Incidence, predictors and therapeutic consequences of hypocalcemia in patients treated with cinacalcet in the EVOLVE trial

The Relationship Between Fracture and Mortality in a Chinese Maintenance Hemodialysis Patients Cohort

Background

Patients on maintenance hemodialysis have an increased risk of fracture. However, the relationship between fracture and poor prognosis is not clear.

Methods

A total of 182 maintenance hemodialysis patients were enrolled in the study. The relationship between fracture and poor prognosis (cardiovascular events, stroke, malignancy and 5-year all-cause mortality) were analyzed.

Results

21 of 182 patients had a history of fracture at the time of enrollment. 26 patients had a new fracture after enrollment. A total of 57 fractures occurred in 47 patients, the most common fracture site was the rib. Patients with fracture group had a higher proportion of elderly and female, higher serum phosphorus and B-type natriuretic peptide and lower hemoglobin, albumin, and potassium compared with those without fracture. Age (OR=3.809, 95% CI: 1.064-8.966, p=0.038), hemoglobin (OR=0.961, 95% CI: 0.925-0.997, p=0.035), and serum phosphorus (OR=3.325, 95% CI:1.104-10.019, p=0.033) were the independent risk factors of new fractures in MHD patients. The incidence of malignancy and 5-year all-cause mortality in patients with fracture was higher than those without fracture (p<0.05). But there was no significant difference in the incidence of acute myocardial infarction or stroke.

Conclusion

25.8% of maintenance hemodialysis patients had at least one fracture, with rib fractures accounting for the highest proportion. Age, hemoglobin and serum phosphorus were the independent risk factors of new fractures. The incidence of malignancy and 5-year all-cause mortality in patients with fracture was higher than those without fracture, but there was no significant difference in the incidence of acute myocardial infarction and stroke.

Hypocalcemia and cardiovascular mortality in cinacalcet users

BACKGROUND

Calcimimetics are widely used in hemodialysis patients and influence serum calcium levels. Although the Kidney Disease: Improving Global Outcomes guidelines argued that low calcium levels induced by calcimimetics may be harmless, large observational studies investigating the association between hypocalcemia and mortality are scarce. We investigated the association between serum calcium levels and cardiovascular mortality in calcimimetics users using the nationwide Japanese registry for dialysis patients.

METHODS

In this 9-year prospective cohort study, the baseline data were collected at the end of 2009. We enrolled patients on maintenance hemodialysis or hemodiafiltration. We employed three models (baseline, time-dependent and time-averaged) to conduct Cox proportional hazard regression analyses.

RESULTS

Cinacalcet was prescribed to 12.7% (N = 22 853) at baseline. The median observation period was 98 (interquartile range 40-108) months and 108 (interquartile range 59-108) months in the whole cohort (N = 180 136) and in cinacalcet users, respectively. Three-quarters of survivors at the end of 2019 had continued calcimimetic therapy for 10 years, corresponding to a mean annual dropout rate of 2.9%. Hypocalcemia was not associated with cardiovascular mortality in the baseline or time-averaged model. In the time-dependent model, however, the lowest calcium decile (corrected calcium <8.4 mg/dL) was significantly associated with higher cardiovascular mortality than the reference (corrected calcium 8.7-8.9 mg/dL) in both cinacalcet users and all patients [hazard ratio (95% confidence interval) 1.32 (1.00, 1.75) and 1.15 (1.05, 1.26), respectively]. Hypocalcemia was especially associated with sudden death and death due to hemorrhagic stroke, heart failure and ischemic heart disease. Higher rate of fatal and non-fatal cardiovascular events was observed in hypocalcemic patients regardless of cinacalcet usage.

CONCLUSIONS

Our findings suggest that transient hypocalcemia was associated with an increased risk of cardiovascular death independent of cinacalcet usage. We should pay attention to hypocalcemia transiently induced by cinacalcet.

Complications of microwave ablation in patients with persistent/recurrent hyperparathyroidism after surgical or ablative treatment

OBJECTIVE

To evaluate the complications associated with microwave ablation (MWA) in treating persistent/recurrent hyperparathyroidism (HPT) post-surgical or ablative treatments.

MATERIALS AND METHODS

From January 2015 to December 2022, 87 persistent/recurrent HPT patients (primary HPT [PHPT]: secondary HPT [SHPT] = 13:74) who underwent MWA after surgical or ablative treatment were studied. Grouping was based on ablation order (initial vs. re-MWA), prior treatment (parathyroidectomy [PTX] vs. MWA), and etiology (PHPT vs. SHPT). The study focused on documenting and comparing treatment complications and analyzing major complication risk factors.

RESULT

Among the 87 patients, the overall complication rate was 17.6% (15/87), with major complications at 13.8% (12/87) and minor complications at 3.4% (3/87). Major complications included recurrent laryngeal nerve (RLN) palsy (12.6%) and Horner syndrome (1.1%), while minor complications were limited to hematoma (3.4%). Severe hypocalcemia noted in 21.6% of SHPT patients. No significant differences in major complication rates were observed between initial and re-MWA groups (10.7% vs. 13.8%, p = 0.455), PTX and MWA groups (12.5% vs. 15.4%, p = 0.770), or PHPT and SHPT groups (15.4% vs. 13.5%, p > 0.999). Risk factors for RLN palsy included ablation of superior and large parathyroid glands (>1.7 cm). All patients recovered spontaneously except for one with permanent RLN palsy in the PTX group (2.1%).

CONCLUSION

Complication rates for MWA post-surgical or ablative treatments were comparable to initial MWA rates. Most complications were transient, indicating MWA as a viable and safe treatment option for persistent/recurrent HPT patients.

Phase 2 study of upacicalcet in Japanese haemodialysis patients with secondary hyperparathyroidism: an intraindividual dose-adjustment study

Background

Upacicalcet is a novel small-molecule calcimimetic agent developed for intravenous injection. Here, we evaluated the long-term efficacy and safety of upacicalcet treatment via intraindividual dose adjustment in haemodialysis patients with secondary hyperparathyroidism (SHPT).

Methods

A phase 2, multicentre, open-label, single-arm study was conducted. Upacicalcet was administered for 52 weeks; the starting dose was 50 μg thrice a week, and then adjusted to 25, 50, 100, 150, 200, 250, or 300 μg, according to the dose-adjustment method set in the protocol. The primary endpoint was the percentage of patients with serum intact parathyroid hormone (iPTH) level achieving a target range of 60-240 pg/mL (target achievement rate) at week 18.

Results

A total of 58 patients were administered upacicalcet. The target achievement rate of serum iPTH level at week 18 was 57.9%, which increased to 80.8% at week 52. The serum-corrected calcium (cCa) level decreased immediately after upacicalcet administration, but no further decrease was observed. Adverse events were observed in 94.8% of patients, and adverse drug reactions (ADRs) occurred in 20.7% of patients. The most common ADR was decreased adjusted calcium in eight patients; dizziness occurred as a serious ADR in one patient. The serum cCa level of patients who interrupted upacicalcet treatment at a serum cCa level of <7.5 mg/dL recovered to ≥7.5 mg/dL immediately after the interruption.

Conclusions

In haemodialysis patients with SHPT, upacicalcet doses of 25-300 μg for 52 weeks were found to be highly effective and well-tolerated, with minor safety concerns.

Hypocalcemia Risk of Denosumab Across the Spectrum of Kidney Disease: A Population-Based Cohort Study

Denosumab can be used in patients with chronic kidney disease (CKD) but has been linked with cases of severe hypocalcemia. The incidence of and risk factors for hypocalcemia after denosumab use are not well established. Using linked health care databases at ICES, we conducted a population-based cohort study of adults >65 years old with a new prescription for denosumab or a bisphosphonate between 2012 and 2020. We assessed incidence of hypocalcemia within 180 days of drug dispensing and stratified results by estimated glomerular filtration rate (eGFR in mL/min/1.73 m² ). We used Cox proportional hazards to assess risk factors for hypocalcemia. There were 59,151 and 56,847 new denosumab and oral bisphosphonate users, respectively. Of the denosumab users, 29% had serum calcium measured in the year before their prescription, and one-third had their serum calcium checked within 180 days after their prescription. Mild hypocalcemia (albumin corrected calcium <2.00 mmol/L) occurred in 0.6% (95% confidence interval [CI] 0.6, 0.7) of new denosumab users and severe hypocalcemia (<1.8 mmol/L) in 0.2% (95% CI 0.2, 0.3). In those with an eGFR <15 or receiving maintenance dialysis, the incidence of mild and severe hypocalcemia was 24.1% (95% CI 18.1, 30.7) and 14.9% (95% CI 10.1, 20.7), respectively. In this group, kidney function and baseline serum calcium were strong predictors of hypocalcemia. We did not have information on over-the-counter vitamin D or calcium supplementation. In new bisphosphonate users, the incidence of mild hypocalcemia was 0.3% (95% CI 0.3, 0.3) with an incidence of 4.7% (95% CI 1.5, 10.8) in those with an eGFR <15 or receiving maintenance dialysis. In this large population-based cohort, we found that the overall risk of hypocalcemia with new denosumab use was low but increased substantially in those with eGFR <15 mL/min/1.73 m² . Future studies should investigate strategies to mitigate hypocalcemia. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Etelcalcetide controls secondary hyperparathyroidism and raises sclerostin levels in hemodialysis patients previously uncontrolled with cinacalcet

INTRODUCTION

There is scarce clinical experience with etelcalcetide in patients with secondary hyperparathyroidism uncontrolled with cinacalcet. The effect of etelcalcetide on serum sclerostin levels remains to be clarified.

MATERIALS AND METHODS

Prospective cohort study in prevalent hemodialysis patients with uncontrolled sHPT under cinacalcet for at least 3 months, mean parathyroid hormone (PTH)>800pg/mL and calcium (Ca)>8.3mg/dL. Etelcalcetide 5mg IV/HD was initiated after cinacalcet washout. Levels of PTH, Ca, and phosphorus (Pi) followed monthly for 6 months. Plasma sclerostin levels measured before etelcalcetide treatment and after 6 months.

RESULTS

Thirty-four patients were enrolled, 19 (55.9%) male gender. Mean age 60.7 (± 12.3) years; median time on HD 82.5 (7-296) months and median cinacalcet dose was 180mg/week (Interquartile Range: 180-270). Serum Ca, Pi and PTH levels showed a significant reduction after etelcalcetide treatment from 8.8mg/dL, 5.4mg/dL and 1005pg/mL to 8.1mg/dL (p=0.08), 4.9mg/dL (p=0.01) and 702pg/mL (p<0.001), respectively. Median etelcalcetide dose remained at 5mg/HD. Plasma sclerostin concentration increased from 35.66pmol/L (IQR11.94-54.58) to 71.05pmol/L (IQR54.43-84.91) (p<0.0001).

CONCLUSION

Etelcalcetide improved sHPT control in this group of patients, previously under cinacalcet treatment, and significantly increased plasma sclerostin concentration. The impact of etelcalcetide treatment on sclerostin levels is a novel finding.

An update on phosphate binders for the treatment of hyperphosphatemia in chronic kidney disease patients on dialysis: a review of safety profiles

INTRODUCTION

Hyperphosphatemia is an inevitable complication for patients undergoing dialysis, as is the resulting need for treatment with phosphate binders. Currently, various phosphate binders are clinically available. In addition to their phosphate-lowering activity, individual phosphate binders have differing safety profiles and off-target actions.

AREAS COVERED

This paper reviews the safety of phosphate binders and issues to be resolved.

EXPERT OPINION

Calcium-based phosphate binders are well tolerated but may increase calcium overload risk. Sevelamer reduces serum cholesterol levels and exerts anti-inflammatory effects. Compared to sevelamer, bixalomer is associated with fewer gastrointestinal symptoms. Aluminum-containing binders, lanthanum carbonate, and sucroferric oxyhydroxide exhibit strong phosphate-lowering activity. Although ferric citrate reduces erythropoiesis-stimulating agents and intravenous iron doses, its use requires monitoring of iron metabolic markers to avoid overload. Occasionally, combined use of multiple phosphate binders can offer the advantages of each phosphate binder while minimizing their drawbacks; thus, this may be desirable according to individual patients' conditions and comorbidities. However, increased pill burden and nonadherence to phosphate binders emerge as new problems. We expect that novel therapeutic strategies will be developed to resolve these issues.

Evocalcet with vitamin D receptor activator treatment for secondary hyperparathyroidism

This ad hoc analysis of a previously conducted phase 3 head-to-head comparison study of evocalcet and cinacalcet in secondary hyperparathyroidism patients undergoing maintenance hemodialysis evaluated the efficacy and safety of combined once-daily oral evocalcet and intravenous vitamin D receptor activator treatment stratified by weekly vitamin D receptor activator dose (117, 45, and 91 patients in no, low [< 1.5 μg], and high [≥ 1.5 μg] dose groups, respectively). Effects of vitamin D receptor activator were assessed on the basis of intact parathyroid hormone, corrected calcium, phosphorus, and fibroblast growth factor-23 levels; percent changes from baseline; proportions of patients who achieved target intact parathyroid hormone, corrected calcium, and phosphorus at Weeks 28–30; and adverse drug reactions. Intact parathyroid hormone, corrected calcium, phosphorus, and fibroblast growth factor-23 levels decreased in all groups; phosphorus and fibroblast growth factor-23 levels remained high in the high dose group. In the low and high dose groups, greater proportions of patients achieved the corrected calcium target compared with the no dose group (p = 0.043). Ratios of intact-to-C-terminal fibroblast growth factor-23 decreased in all groups. In low and high dose groups, hypocalcemia was less common than in the no dose group (p = 0.014). Evocalcet with concomitant vitamin D receptor activator demonstrated benefits such that more patients achieved the corrected calcium target and exhibited decreased fibroblast growth factor-23 synthesis; the incidence of hypocalcemia also decreased.

Clinical trial registration: ClinicalTrials.gov (NCT02549391) and JAPIC (JapicCTI-153013).

Severe Symptomatic Hypocalcemia, complicating cardiac arrhythmia following Cinacalcet (SensiparTM) administration: A Case Report

Clinicians should closely monitor patients on calcimimetics for hypocalcemic symptoms and arrhythmia, even though asymptomatic hypocalcemia typically resolves without intervention.

Clinical factors associated with early and persistent hypocalcaemia after parathyroidectomy in patients on dialysis with severe hyperparathyroidism

AIM

Severe hypocalcaemia following parathyroidectomy for secondary or tertiary hyperparathyroidism (SHPT/THPT) is scarcely studied. We aimed to describe and identify risk factors for early and persistent hypocalcaemia after parathyroidectomy.

METHODS

Retrospective pair-matched cohort study. We assessed 87 dialysis patients with SHPT (n = 73) or THPT (n = 14) paired with 146 subjects with primary hyperparathyroidism (PHPT) who underwent parathyroidectomy and were followed for 12 months. Early severe hypocalcaemia was defined as a free Ca ≤0.8 mmol/L [3.2 mg/dl] or corrected Ca ≤1.87 mmol/L [7.5 mg/dl] within 48 h. After parathyroidectomy and persistent hypocalcaemia, as an elemental Ca intake >3.0 g/day to achieve corrected Ca >2 mmol/L [8.0 mg/dl].

RESULTS

Early severe hypocalcaemia occurred in 77% (67/87) versus 6.8% (10/146) of subjects with SHPT/THPT and PHPT, respectively (p < .001). In SHPT/THPT cases, persistent hypocalcaemia occurred in 77% (49/64) and 64% (35/54) after 6 and 12 months of parathyroidectomy, respectively. In PHPT cases, persistent hypocalcaemia occurred in 6.8% (10/146) after 4-12 months of parathyroidectomy. Preoperative serum alkaline phosphatase (ALP) was the only risk factor associated to early severe hypocalcaemia (OR 7.3, 95% C.I. 1.7-10.9, p = .006) and persistent hypocalcaemia (OR 7.1, 95% C.I: 2.1-14.2, p = .011). Subjects with persistently low intact parathormone (iPTH) (<5.3 pmol/L [50 ng/ml]), suggestive of adynamic bone disease) showed higher Ca increases and less oral calcium requirements compared to those who progressively increased iPTH after parathyroidectomy.

CONCLUSION

Early and persistent hypocalcaemia after parathyroidectomy in severe HPT were a common event associated directly to preoperative ALP levels. Subjects with persistently low postoperative iPTH normalized serum Ca more frequently after 1 year of follow up.

One-year safety and efficacy of intravenous etelcalcetide in patients on hemodialysis with secondary hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism (sHPT), a common complication of chronic kidney disease, is characterized by elevated serum parathyroid hormone (PTH). Etelcalcetide is an intravenous calcimimetic that increases sensitivity of the calcium-sensing receptor to calcium and decreases PTH secretion. This open-label extension (OLE) trial evaluated the long-term effects of etelcalcetide for sHPT treatment in patients receiving hemodialysis.

METHODS

This 52-week, multicenter, single-arm OLE enrolled patients from three parent trials: two randomized, double-blind, placebo-controlled trials and one open-label, single-arm, 'switch' study from cinacalcet to etelcalcetide. The primary endpoint was to investigate the nature, frequency, severity and relation to treatment of all adverse events (AEs) reported throughout the trial. Secondary endpoints included the proportion of patients with >30% reduction from baseline in PTH and the percentage change from baseline in PTH, albumin-corrected calcium (Ca), phosphate (P) and the calcium-phosphate product (Ca × P).ClinicalTrials.gov identifier: NCT01785875; Amgen study: 20120231.

RESULTS

Overall, 89.8% of the patients experienced one or more treatment-emergent AE. The most common were decreased blood Ca (43.3%), diarrhea (10.8%), vomiting (10.4%) and nausea (9.6%); symptomatic hypocalcemia occurred in 3.7% of the patients. Approximately 68% of patients achieved >30% reduction in PTH, and ∼56% achieved PTH ≤300 pg/mL. Mean percent changes from baseline ranged from -25.4% to -26.1% for PTH, -8.3% to -9.1% for Ca, -3.6% to -4.1% for P and -12.0% to -12.6% for Ca × P.

CONCLUSIONS

Etelcalcetide effectively lowered PTH and its effect was sustained, while no new safety concerns emerged over a 1-year treatment period.

Association of changes in bone mineral parameters with mortality in haemodialysis patients: insights from the ARO cohort

BACKGROUND

There is little information in haemodialysis (HD) patients on whether temporal changes in serum calcium, phosphate or intact parathyroid hormone (iPTH) are associated with mortality.

METHODS

We analysed associations of phosphate, total calcium and iPTH with all-cause and cardiovascular mortality in 8817 incident HD patients from the European second Analyzing Data, Recognizing Excellence and Optimizing Outcomes (AROii) cohort enrolled in 2007-09, which were prospectively followed for a median of 3 years, using time-dependent Cox proportional hazards models. We evaluated changes in risk over time depending on changes in phosphate, calcium or iPTH.

RESULTS

The association of phosphate and iPTH with all-cause mortality was U-shaped, with the lowest risk ranges between 1.20 and 1.89 mmol/L for phosphate and between 239 and 710 ng/L for iPTH. For total calcium, the associations were J-shaped, with an increased risk for all-cause mortality at levels >2.36 mmol/L. Lowest risk ranges for cardiovascular mortality did not change markedly for all three parameters. If iPTH was below the lowest risk range at baseline (iPTH <239 ng/L), a subsequent increase in levels was associated with improved survival. For phosphate, an increase or decrease out of the lowest risk range was associated with increased mortality risk. For calcium, this was only the case when the values increased above the lowest risk range.

CONCLUSION

In the AROii cohort, the ranges of bone mineral biomarkers associated with the lowest mortality ranges were largely consistent with the current Kidney Disease: Improving Global Outcomes chronic kidney disease-mineral and bone disorder guideline recommendations. Allowing a suppressed iPTH to increase was associated with a lower mortality, whereas shifts of phosphate or calcium outside the lowest risk range increased mortality.

Age, Gender and Season Are Good Predictors of Vitamin D Status Independent of Body Mass Index in Office Workers in a Subtropical Region

This study aimed at determining the prevalence and predictors of hypovitaminosis D (serum 25-hydroxyvitamin D < 30 ng/mL) among office workers in a subtropical region from an electronic hospital database. Totally, 2880 office workers aged 26–65 years who received health examinations with vitamin D status and total calcium concentrations at a tertiary referral center were retrospectively reviewed. Subjects were divided into groups according to genders, age (i.e., 26–35, 36–45, 46–55, 56–65), body-mass index (BMI) (i.e., obese BMI ≥ 30, overweight 25 ≤ BMI < 30, normal 20 ≤ BMI < 25, and underweight BMI < 20) and seasons (spring/winter vs. summer/autumn) for identifying the predictors of hypovitaminosis D. Corrected total calcium level <8.4 mg/dL is considered as hypocalcemia. Multivariate logistic regression demonstrated that females (AOR 2.33, (95% CI: 1.75, 3.09)), younger age (4.32 (2.98, 6.24), 2.82 (1.93, 4.12), 1.50 (1.03, 2.17)), and season (winter/spring) (1.55 (1.08, 2.22)) were predictors of hypovitaminosis D, whereas BMI was not in this study. Despite higher incidence of hypocalcemia in office workers with hypovitaminosis D (p < 0.001), there was no association between vitamin D status and corrected total calcium levels. A high prevalence (61.9%) of hypovitaminosis D among office workers in a subtropical region was found, highlighting the importance of this occupational health issue.

Cinacalcet use in paediatric dialysis: a position statement from the European Society for Paediatric Nephrology and the Chronic Kidney Disease-Mineral and Bone Disorders Working Group of the ERA-EDTA

Secondary hyperparathyroidism (SHPT) is an important complication of advanced chronic kidney disease (CKD) in children, which is often difficult to treat with conventional therapy. The calcimimetic cinacalcet is an allosteric modulator of the calcium-sensing receptor. It has proven to be effective and safe in adults to suppress parathyroid hormone (PTH), but data on its use in children are limited. To date, studies in children only consist of two randomized controlled trials, nine uncontrolled interventional or observational studies, and case reports that report the efficacy of cinacalcet as a PTH-lowering compound. In 2017, the European Medical Agency approved the use of cinacalcet for the treatment of SHPT in children on dialysis in whom SHPT is not adequately controlled with standard therapy. Since evidence-based guidelines are so far lacking, we present a position statement on the use of cinacalcet in paediatric dialysis patients based on the available evidence and opinion of experts from the European Society for Paediatric Nephrology, Chronic Kidney Disease-Mineral and Bone Disorder and Dialysis Working Groups, and the ERA-EDTA. Given the limited available evidence the strength of these statements are weak to moderate, and must be carefully considered by the treating physician and adapted to individual patient needs as appropriate. Audit and research recommendations to study key outcome measures in paediatric dialysis patients receiving cinacalcet are suggested.

Canadian Society of Nephrology Commentary on the Kidney Disease Improving Global Outcomes 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder

Purpose of review:

(1) To provide commentary on the 2017 update to the Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD); (2) to apply the evidence-based guideline update for implementation within the Canadian health care system; (3) to provide comment on the care of children with chronic kidney disease (CKD); and (4) to identify research priorities for Canadian patients.

Sources of information:

The KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD.

Methods:

The commentary committee co-chairs selected potential members based on their knowledge of the Canadian kidney community, aiming for wide representation from relevant disciplines, academic and community centers, and different geographical regions.

Key findings:

We agreed with many of the recommendations in the clinical practice guideline on the diagnosis, evaluation, prevention, and treatment of CKD-MBD. However, based on the uncommon occurrence of abnormalities in calcium and phosphate and the low likelihood of severe abnormalities in parathyroid hormone (PTH), we recommend against screening and monitoring levels of calcium, phosphate, PTH, and alkaline phosphatase in adults with CKD G3. We suggest and recommend monitoring these parameters in adults with CKD G4 and G5, respectively. In children, we agree that monitoring for CKD-MBD should begin in CKD G2, but we suggest measuring ionized calcium, rather than total calcium or calcium adjusted for albumin. With regard to vitamin D, we suggest against routine screening for vitamin D deficiency in adults with CKD G3-G5 and G1T-G5T and suggest following population health recommendations for adequate vitamin D intake. We recommend that the measurement and management of bone mineral density (BMD) be according to general population guidelines in CKD G3 and G3T, but we suggest against routine BMD testing in CKD G4-G5, CKD G4T-5T, and in children with CKD. Based on insufficient data, we also recommend against routine bone biopsy in clinical practice for adults with CKD or CKD-T, or in children with CKD, although we consider it an important research tool.

Limitations:

The committee relied on the evidence summaries produced by KDIGO. The CSN committee did not replicate or update the systematic reviews.

Hypocalcemia after ultrasound-guided microwave ablation and total parathyroidectomy for secondary hyperparathyroidism: a retrospective study

OBJECTIVE

To compare the postoperative hypocalcemia between ultrasound-guided microwave ablation (MWA) and total parathyroidectomy (TPTX) for secondary hyperparathyroidism (SHPT).

METHODS

The retrospective study reviewed 286 SHPT patients (171 received MWA and 115 underwent TPTX) between March 2018 and May 2019. Propensity-score matching was used to assemble a cohort of patients with similar baseline characteristics. A total of 184 SHPT patients (92 in each group) were finally enrolled, the occurrence and prognosis of postoperative hypocalcemia were compared. And the risk factors associated with severe hypocalcemia (SH) in each group were analyzed.

RESULTS

Hypocalcemia encountered in 95cases (49 in the MWA group and 46 in the TPTX group). SH occurred in 76 cases (40 in the MWA group and 36 in the TPTX group). There were no statistically significant differences in the detection time, incidence, minimum value of serum calcium and symptomatic hypocalcemia between MWA and TPTX group (all p values > 0.05). Of patients developing hypocalcemia, serum calcium did not recover to normal range in 5 cases (10.2%) in the MWA group, while 13 cases (28.3%) were still hypocalcemia at 6 months follow-up in TPTX group (p = 0.035). The time to recovery from hypocalcemia in the TPTX group (mean 30 days, range 3-180 days) was longer than the WA group (mean 14 days, range 3-126 days) (p = 0.000). High serum alkaline phosphatase (ALP) level and low serum calcium level were the main risk factors of postoperative SH.

CONCLUSION

There was no difference in hypocalcemia between MWA and TPTX group. Hypocalcemia in the TPTX group might need a longer time to recover.

Cinacalcet and primary hyperparathyroidism: systematic review and meta regression

PURPOSE

Primary hyperparathyroidism (PHPT) is a common condition affecting people of all ages and is mainly treated with parathyroidectomy. Cinacalcet has been widely used in secondary or tertiary hyperparathyroidism, but the use of cinacalcet in PHPT is less clear.

METHODS

Searches were conducted in Medline and Embase for cinacalcet use in PHPT from induction to 10 April 2020. Articles and conferences abstracts describing the use of cinacalcet for PHPT in prospective or retrospective cohorts and randomized controlled trials restricted to English language only. We initially identified 1301 abstracts. Each article went extraction by two blinded authors on a structured proforma. Continuous outcomes were pooled with weight mean difference (WMD). Quality of included articles was assessed with Newcastle Ottwa Scale and Cochrane Risk of Bias 2.0.

RESULTS

Twenty-eight articles were included. Normalization rate of serum Ca levels was reported at 90% (CI: 0.82 to 0.96). Serum levels of Ca and PTH levels were significantly reduced (Ca, WMD: 1.647, CI: -1.922 to -1.371; PTH, WMD: -31.218, CI: -41.671 to -20.765) and phosphate levels significantly increased (WMD: 0.498, CI: 0.400 to 0.596) after cinacalcet therapy. The higher the baseline Ca levels, the greater Ca reduction with cinacalcet treatment. Age and gender did not modify the effect of cinacalcet on serum Ca levels.

CONCLUSION

The results from the meta-analysis support the use of cinacalcet as an alternative or bridging therapy to treat hypercalcemia in people with PHPT.

Cinacalcet-Associated Resolution of Primary Hyperparathyroidism in a Patient With Normal Kidney Function

Cinacalcet use is associated with risk of hypocalcemia; however, this risk has been mostly demonstrated in patients with chronic kidney disease. In this article, we describe a case of a 59-year-old male with primary hyperparathyroidism (PHPT), hypercalciuria, osteopenia, and normal kidney function who was started on cinacalcet for the management of recurrent hypercalcemia following prior unsuccessful parathyroidectomy. Within 6 months following cinacalcet commencement, he developed symptomatic and biochemical hypocalcemia requiring discontinuation of the medication and initiation of calcium supplementation. Over more than 3 years of follow-up, his calcium supplementation was gradually tapered off and then discontinued. He is presently eucalcemic and euparathyroid off calcium supplements while also demonstrating normalization of hypercalciuria and bone mineral density. These data indicate that our patient has experienced resolution of PHPT after brief exposure to cinacalcet. We recommend that low starting cinacalcet doses should be considered for treatment of hypercalcemia in patients with PHPT who underwent unsuccessful parathyroidectomy along with close clinical and biochemical follow-up.

Risk Factors of Severe Hypocalcemia After US-Guided Percutaneous Microwave Ablation of the Parathyroid Gland in Patients with Secondary Hyperparathyroidism

Our aim was to identify potential risk factors associated with severe hypocalcemia (SH) after microwave ablation (MWA) in patients with secondary hyperparathyroidism (SHPT). This retrospective cross-sectional study enrolled 204 consecutive patients (with 387 parathyroid glands) who underwent MWA between July 2015 and May 2018. Clinical parameters, laboratory indices, and parathyroid gland characteristics were analyzed to assess risk factors associated with SH after MWA. SH was defined as serum calcium level lower than 1.875 mmol/L (7.5 mg/dL) after MWA. Two models (I and II) for pre-MWA and post-MWA prediction were established, respectively. In accordance with the KDIGO guidelines, the target value for intact parathyroid hormone (iPTH) less than 300 pg/mL within 7 days after MWA was considered as a successful procedure. The success rate of MWA was 71.6% (146/204). The incidence of hypocalcemia and SH after MWA was 35.8% and 22.06%, respectively. The pre-MWA prediction models I and II showed that high pre-MWA iPTH, a dramatic reduction in iPTH, low pre-MWA serum calcium, multiple ablated gland, and lack of pruritus symptoms were risk factors for developing SH. The accuracy (82.23% versus 83.25% in models I and II, respectively), sensitivity (34.88% versus 44.19%), specificity (95.45% versus 94.59%), positive predictive value (PPV) (68.18% versus 70.37%), and negative predictive value (NPV) (84% versus 85.37%) of both models were promising. The logistic regression fitting of the nomograms showed high prediction efficiency (0.845 and 0.863). High pre-MWA iPTH, dramatic reductions in iPTH, low pre-MWA serum calcium, multiple gland ablation, and no pruritus symptoms were predictors of SH. © 2019 American Society for Bone and Mineral Research.

Cinacalcet-induced hypocalcemia in a cohort of European haemodialysis patients: predictors, therapeutic approaches and outcomes

BACKGROUND

Calcimimetic treatment of secondary hyperparathyroidism in chronic dialysis patients is often followed by hypocalcemia.

METHODS

We investigated the frequency, predictors, consequences and therapeutic responses following cinacalcet-induced hypocalcemia in an incident European hemodialysis cohort of 1068 patients with a cinacalcet prescription.

RESULTS

Of 905 normocalcemic patients initiating cinacalcet, 67% developed hypocalcemia within 12 months: 68% mild, 23% moderate, 9% severe. Compared to persistently normocalcemic patients, those with severe hypocalcemia were more often diabetic, overweight, had cardiovascular disease, shorter dialysis vintage, used a catheter dialysis access, had fewer active vitamin-D sterols, and exhibited higher CRP and iPTH and lower calcium levels. Multivariate predictors of hypocalcemia included a catheter for vascular access, low albumin and high iPTH. Generally, no therapeutic intervention to prevent hypocalcemia was taken prior to cinacalcet initiation. After the hypocalcemic event, the most common clinical response was no change of the dialysis or medical regimen. Following the hypocalcemic event, iPTH remained low even in those with severe hypocalcemia. The number of deaths and cardiovascular events did not differ between patients with and without hypocalcemia within six months following cinacalcet initiation.

CONCLUSION

Two-thirds of cinacalcet initiated patients experienced hypocalcaemia with 9% being severe. Hypocalcemia was mostly asymptomatic, transient (with and without targeted intervention to correct it) and not associated with an increase in cardiovascular events or deaths.

Cinacalcet Treatment Significantly Improves All-Cause and Cardiovascular Survival in Dialysis Patients: Results from a Meta-Analysis

OBJECTIVE

To assess the long-term effects including all-cause mortality, cardiovascular mortality, and fracture incidence, of cinacalcet on secondary hyperparathyroidism (SHPT) in patients on dialysis.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched from their inception to October 2018. Randomized controlled trials (RCTs) and cohort design prospective observational studies assessing cinacalcet for the treatment of SHPT in dialysis patients were included. Data extraction was independently completed by 2 authors who determined the methodological quality of the studies and extracted data in duplicate. Study-specific risk estimates were tested by using a fixed effects model.

RESULTS

A total of 14 articles with 38,219 participants were included, of which 10 RCTs with 7,471 participants and 4 prospective observational studies with 30,748 participants fulfilled the eligibility criteria. Compared with no cinacalcet, cinacalcet administration reduced all-cause mortality (relative risk [RR] 0.91, 95% CI 0.89-0.94, p < 0.001) and cardiovascular mortality (RR 0.92, 95% CI 0.89-0.95, p < 0.001), but it did not significantly reduce the incidence of fractures (RR 0.93, 95% CI 0.87-1.00, p = 0.05).

CONCLUSIONS

The results of this meta-analysis indicated that the treatment of SHPT with cinacalcet may in fact reduce all-cause mortality and cardiovascular mortality among patients receiving maintenance dialysis.

The impact of cinacalcet in the mineral metabolism markers of patients on dialysis with severe secondary hyperparathyroidism

INTRODUCTION

Treating secondary hyperparathyroidism (SHPT), a common condition associated with death in patients with chronic kidney disease, is a challenge for nephrologists. Calcimimetics have allowed the introduction of drug therapies no longer based on phosphate binders and active vitamin D. This study aimed to assess the safety and effectiveness of cinacalcet in managing chronic dialysis patients with severe SHPT.

METHODS

This retrospective study included 26 patients [age: 52 ± 12 years; 55% females; time on dialysis: 54 (4-236) months] on hemodialysis (N = 18) or peritoneal dialysis (N = 8) with severe SHPT (intact parathyroid hormone (iPTH) level > 600 pg/mL) and hyperphosphatemia and/or persistent hypercalcemia treated with cinacalcet. The patients were followed for 12 months. Their serum calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), and iPTH levels were measured at baseline and on days 30, 60, 90, 180, and 365.

RESULTS

Patients with hyperphosphatemia (57.7%), hypercalcemia (23%), or both (19.3%) with iPTH > 600 pg/mL were prescribed cinacalcet. At the end of the study, decreases were observed in iPTH (1348 ± 422 vs. 440 ± 210 pg/mL; p < 0.001), Ca (9.5 ± 1.0 vs. 9.1 ± 0.6 mg/dl; p = 0.004), P (6.0 ± 1.3 vs. 4.9 ± 1.1 mg/dl; p < 0.001), and ALP (202 ± 135 vs. 155 ± 109 IU/L; p = 0.006) levels. Adverse events included hypocalcemia (26%) and digestive problems (23%). At the end of the study, 73% of the patients were on active vitamin D and cinacalcet. Three (11.5%) patients on peritoneal dialysis did not respond to therapy with cinacalcet, and their iPTH levels were never below 800 pg/mL.

CONCLUSION

Cinacalcet combined with traditional therapy proved safe and effective and helped manage the mineral metabolism of patients with severe SHPT.

Predictors of cinacalcet discontinuation and reinitiation in hemodialysis patients: results from 7 European countries

Background

The putative benefits of cinacalcet therapy for management of secondary hyperparathyroidism (SHPT) are thought to be most manifested when patients are taking it consistently and as prescribed. Real-world descriptions of cinacalcet prescription discontinuation and reinitiation in European hemodialysis patients are lacking. To address this knowledge gap, we used Dialysis Outcomes and Practice Patterns Study (DOPPS) data, based on dialysis facility medical records, from seven European countries to estimate rates and predictors of cinacalcet prescription discontinuation and reinitiation in hemodialysis patients and to describe the trajectories of CKD-MBD laboratory values after discontinuation.

Methods

Cox regression analyses were used to predict (1) cinacalcet discontinuation among 613 patients with ≥3 consecutive months without cinacalcet prescription immediately prior to a new cinacalcet prescription and (2) cinacalcet reinitiation among 415 patients with a newly discontinued cinacalcet prescription immediately after ≥3 consecutive months of prescribed use.

Results

Cinacalcet was discontinued in 21 and 35% of new users after 6 and 12 months, respectively. Cinacalcet was reinitiated in 38 and 49% of newly-discontinued users after 6 and 12 months, respectively. Predictors of discontinuation included lower parathyroid hormone (PTH) in the previous month (< 150 pg/ml vs. 150–299, HR = 2.57 [95% CI: 1.52–4.33]) and lower serum calcium in the previous month (< 8.4 mg/dl vs. 8.4–10.19, HR = 1.67 [95% CI: 1.08–2.59]). Predictors of reinitiation included higher PTH in the previous month (300–599 pg/ml vs. 150–299, HR = 1.88 [95% CI = 1.19–2.97]; 600+ pg/ml, HR = 3.02 [95% CI = 1.92–4.76]). After cinacalcet discontinuation, mean serum PTH increased from 408 to 510 pg/ml, mean serum calcium briefly rose from 9.12 to 9.22 mg/dl before declining to 9.06 mg/dl, and mean serum phosphorus showed little change.

Conclusions

Nephrologist discontinuation of cinacalcet therapy is common in European countries. Additional research is needed to identify optimal cinacalcet treatment strategies for SHPT management, including comparisons of intermittent cinacalcet therapy versus sustained treatment with reduced dose or frequency.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1355-5) contains supplementary material, which is available to authorized users.

Activation of the calcium sensing receptor attenuates TRPV6-dependent intestinal calcium absorption

Plasma calcium (Ca2+) is maintained by amending the release of parathyroid hormone and through direct effects of the Ca2+ sensing receptor (CaSR) in the renal tubule. Combined, these mechanisms alter intestinal Ca2+ absorption by modulating 1,25-dihydroxy vitamin D3 production, bone resorption, and renal Ca2+ excretion. The CaSR is a therapeutic target in the treatment of secondary hyperparathyroidism and hypocalcemia a common complication of calcimimetic therapy. The CaSR is also expressed in intestinal epithelium, however, a direct role in regulating local intestinal Ca2+ absorption is unknown. Chronic CaSR activation decreased expression of genes involved in Ca2+ absorption. In Ussing chambers, increasing extracellular Ca2+ or basolateral application of the calcimimetic cinacalcet decreased net Ca2+ absorption across intestinal preparations acutely. Conversely, Ca2+ absorption increased with decreasing extracellular Ca2+ concentration. These responses were absent in mice expressing a non-functional TRPV6, TRPV6D541A. Cinacalcet also attenuated Ca2+ fluxes through TRPV6 in Xenopus oocytes when co-expressed with the CaSR. Moreover, the phospholipase C inhibitor, U73122, prevented cinacalcet-mediated inhibition of Ca2+ flux. These results reveal a regulatory pathway whereby activation of the CaSR in the basolateral membrane of the intestine directly attenuates local Ca2+ absorption via TRPV6 to prevent hypercalcemia and help explain how calcimimetics induce hypocalcemia.

Calcimimetics and Bundled Reimbursement

Since 2011, the Centers for Medicare & Medicaid Services has provided reimbursement for renal dialysis services furnished to Medicare beneficiaries through a bundled payment system known as the Prospective Payment System. Medications that have no injectable equivalent, known as "oral-only medications," are currently excluded from the bundle and are paid separately through Medicare Part D. Thus, before the development of etelcalcetide, the first injectable calcimimetic, calcimimetics were reimbursed outside the bundle. Etelcalcetide's introduction and approval for use in Medicare triggered a transition payment for a minimum of 2 years that will eventually result in the incorporation of calcimimetics into the dialysis bundle. Consequently, providers may face incentives to reduce calcimimetic use when the transition period has expired. The complexity of bone-mineral management in conjunction with the paucity of evidence-based recommendations in this area makes it difficult to predict the impact of this transition. Because these medications are expensive, a poor transition could have financial ramifications for dialysis organizations and potentially patient health. To ensure that patients are not adversely affected, it is critical that Medicare incorporate these medications into the bundle carefully, with close monitoring of outcomes.

Role of etelcalcetide in the management of secondary hyperparathyroidism in hemodialysis patients: a review on current data and place in therapy

Secondary hyperparathyroidism (sHPT) is a frequently occurring severe complication of advanced kidney disease. Its clinical consequences include extraskeletal vascular and valvular calcifications, changes in bone metabolism resulting in renal osteodystrophy, and an increased risk of cardiovascular morbidity and mortality. Calcimimetics are a cornerstone of parathyroid hormone (PTH)-lowering therapy, as confirmed by the recently updated 2017 Kidney Disease: Improving Global Outcomes chronic kidney disease – mineral and bone disorder clinical practice guidelines. Contrary to calcitriol or other vitamin D-receptor activators, calcimimetics reduce PTH without increasing serum-calcium, phosphorus, or FGF23 levels. Etelcalcetide is a new second-generation calcimimetic that has been approved for the treatment of sHPT in adult hemodialysis patients. Whereas the first-generation calcimimetic cinacalcet is taken orally once daily, etelcalcetide is given intravenously thrice weekly at the end of the hemodialysis session. Apart from improving drug adherence, etelcalcetide has proven to be more effective in lowering PTH when compared to cinacalcet, with an acceptable and comparable safety profile. The hope for better gastrointestinal tolerance with intravenous administration did not come true, as etelcalcetide did not significantly mitigate the adverse gastrointestinal effects associated with cinacalcet. Enhanced adherence and strong reductions in PTH, phosphorus, and FGF23 could set the stage for a future large randomized controlled trial to demonstrate that improved biochemical control of mineral metabolism with etelcalcetide in hemodialysis patients translates into cardiovascular and survival benefits and better health-related quality of life.