[Long-term efficacy of parathyroidectomy in secondary and tertiary hyperparathyroidism]

BACKGROUND

Secondary and tertiary hyperparathyroidism (SHPT and THPT), are complications of chronic kidney disease (CKD), characterized by high levels of serum parathormone, hyperphosphatemia or hypercalcemia, respectively. If diet and pharmacological therapies fail, clinical practice guidelines suggest parathyroidectomy (PTX). Some studies have described its effectiveness and safety, but these have not included Mexican population.

OBJECTIVE

To describe long-term effectiveness of PTX in Mexican patients with SHPT or THPT.

MATERIAL AND METHODS

Observational and retrospective study of patients treated with PTX between 1995 and 2014 in a third level hospital in Mexico City. The analyses included the follow-up of medical treatment and biochemical assessment every three months during the first year, and the last evaluation. Permutation and chi square tests were used.

RESULTS

The study included 27 patients (14 women). The follow-up mean was 39 months; 61.5% had SHPT. All biochemical parameters, except magnesium, were reduced in the first year of follow-up. In the long term, SHPT was controlled in 80% using PTH under a 300 pg/mL criterion, and 90% in patients with THPT using calcium criterion. Persistent hypocalcemia was present in 11.5% of cases.

CONCLUSION

Mexican patients with SHPT and THPT could be successfully treated with surgery with low risk of hypocalcemia.

Impact of Subtotal Parathyroidectomy on Clinical Parameters and Quality of Life in Hemodialysis Patients with Secondary Hyperparathyroidism

BACKGROUND

Impairment of quality of life (QOL) is a key clinical characteristic of patients with end-stage renal disease (ESRD), and can be especially severe in the presence of secondary hyperparathyroidism (SHPT). Despite the proven success of parathyroidectomy (PTX) in controlling biochemical parameters in patients with severe SHPT, evidence is lacking regarding the effects of PTX on various clinical outcomes, including QOL.

METHODS

Twenty ESRD patients on maintenance hemodialysis with SHPT who underwent subtotal PTX were included in an observational longitudinal study. All studied patients underwent history-taking, clinical examinations, and laboratory investigations, including a complete blood count and measurements of serum calcium, phosphorus, magnesium, parathyroid hormone (PTH), and albumin levels preoperatively and at 3 months postoperatively. QOL was assessed before surgery and at 3 months after surgery using the Kidney Disease Quality of Life 36-Item Short-Form instrument.

RESULTS

After PTX, significant decreases in serum PTH and phosphorus levels were observed, as well as a significant increase in serum magnesium levels. Significant weight gain and improvements of QOL were also detected postoperatively.

CONCLUSION

Subtotal PTX seems to be an efficient alternative to medical management in uncontrolled cases of SHPT, as it is capable of controlling the biochemical derangements that occur in hyperparathyroidism. Furthermore, PTX had a beneficial effect on clinical outcomes, as shown by weight gain and improvements in all QOL scales.

Management of Post-transplant Hyperparathyroidism and Bone Disease

Significant advances in immunosuppressive therapies have been made in renal transplantation, leading to increased allograft and patient survival. Despite improvement in overall patient survival, patients continue to require management of persistent post-transplant hyperparathyroidism. Medications that treat persistent hyperparathyroidism include vitamin D, vitamin D analogues, and calcimimetics. Medication side effects such as hypocalcemia or hypercalcemia, and adynamic bone disease, may lead to a decrease in the drugs. When medical management fails to control persistent post-transplant hyperparathyroidism, treatment is a parathyroidectomy. Surgical techniques are not uniform between centers and surgeons. Undergoing the surgery may include a subtotal technique or a technique including total parathyroid gland resection with partial heterotopic gland reimplantation. In addition, there are possible post-surgical complications. The ideal treatment for persistent post-transplant hyperparathyroidism is the treatment and prevention of the condition while patients are being managed for their late-stage chronic kidney disease and end-stage renal disease.

The Value of Imaging of the Parathyroid Glands in Secondary Hyperparathyroidism

It is estimated that up to 90% of patients with chronic kidney disease develop secondary hyperparathyroidism (sHPT). Although the disease has multiple manifestations, the most important pathological feature, from the point of view of increased mortality, is represented by the ectopic arterial, myocardial and cardiac valvular calcifications. The calcifications are progressive and lead to high blood pressure, left ventricular hypertrophy, atrio-ventricular blocks, angina and myocardial infarction. Therefore the risk of cardio-vascular events is increased. Failure of drug therapy to control disease progression is an indication for parathyroidectomy. In sHPT all parathyroid glands are affected, hence the need to detect 4 glands intraoperatively, by bilateral cervical exploration. However, considering the possibility of ectopic localization of these glands as well as the possibility of some supernumerary glands, it is desirable to have an imagistic map as accurate as possible, thus avoiding the risk of postoperative recurrence. The available imaging investigations are represented by the ultrasound of the cervical region, the parathyroid scintigraphy and those of the second line - CT or MRI examination. If in primary hyperparathyroidism, where there is only one parathyroid adenoma (or two), the preoperative imaging results are satisfactory, in sHPT there are many cases in which the imaging does not reveal all four parathyroid glands.

Clinical Aspects of Parathyroid Hyperplasia in Secondary Renal Hyperparathyroidism

The secondary hyperparathyroidism (sHPT) affects all patients with chronic renal failure in different degrees. The chronic kidney disease is often associated with multiple severe comorbidities, therefore the figures for mortality are higher than in the general population. The failure of medical treatment is an indication for surgical treatment. The recurrence of the disease in secondary hyperpara-thyroidism after surgical treatment using total parathyroid with autotransplantation or subtotal parathyroidectomy may be a challenge due to hyperplasia of the remaining tissue. The purpose of this retrospective study was to highlight the risk factors for the occurrence of glandular hyperplasia in patients with secondary hyperparathyroidism and to determine optimal surgery approach for secondary hyperparathyroidism in order to minimize relapse rates. Parathyroid size evaluation may suggest the presence of nodular hyperplasia contributing to an early parathyroidectomy and at the same time selecting the best surgical treatment for sHPT patients. As resistance to medical therapy is due to the presence of nodular hyperplasia, some authors recomends subtotal parathyroidectomy with the excision of these glands, with the remaining parathyroids tissue and function controlled by medical therapy (20).

Total parathyroidectomy plus multi-point subcutaneous transplantation in the forearm may be a reliable surgical approach for patients with end-stage renal disease: A case report

RATIONALE

We studied the feasibility of total arathyroidectomy(tPTX)+multi-point transplantation in the forearm for treatment of secondary hyperparathyroidism. Considering the controversial nature of the appropriate timing for and location of this type of surgery, relevant research is relatively rare. Our experience may be a relatively successful one.

PATIENT CONCERNS

Our patient was a 28-year-old woman with end-stage renal disease (ESRD), who was on dialysis for 7 years, and a 2-year history of progressively aggravated bone pain. She also had hypercalcemia and hyperphosphatemia.

DIAGNOSES

Given the patient's history of long-term dialysis, bone pain, high levels of intact parathyroid hormone(i-PTH) and hypercalcemia, we performed ultrasonography which showed solid nodules in the bilateral parathyroid glands. She was accordingly diagnosed with SHPT.

INTERVENTIONS

The patient underwent tPTX+multi-point subcutaneous transplantation in the forearm.

OUTCOMES

Her i-PTH level dropped to < 300 pg/mL, and the symptoms of bone pain markedly reduced after surgery.

LESSONS

Total parathyroidectomy+multi-point subcutaneous transplantation in the forearm may be a reliable surgical approach for patients with ESRD.

Clinical outcomes of parathyroidectomy versus cinacalcet in the clinical management of secondary hyperparathyroidism

Parathyroidectomy (PTX) is the standard treatment for secondary hyperparathyroidism (SHPT); however, the administration of cinacalcet has gained prominence as a noninvasive treatment. We aimed to determine whether PTX or cinacalcet is more effective in preventing morbidity and mortality through reviewing follow-up data concerning surgical management of SHPT. We retrospectively analyzed and divided 209 patients with SHPT into two treatment groups: PTX (n = 78) and cinacalcet (n = 131) groups. We compared clinical features, the over-the-target range rate during pre- and post-intervention periods, new cardiovascular events, and all-cause mortality between both groups. Almost all biochemical parameters were well controlled in the post-intervention period, and were within the recommended target range for the PTX group but not for the cinacalcet group. A significant difference was observed in the over-the-target range rate during the post-intervention period between the groups. PTX and cinacalcet interventions significantly lowered the over-the-target range rates for serum intact parathyroid hormone (iPTH) (>300 pg/mL), corrected calcium (>10.5 mg/mL), serum phosphorus (>5.5 mg/dL), and calcium-phosphorus product (>55) in both groups (p = 0.001). PTX reduced the risk of new cardiovascular events by 86% compared to cinacalcet (p = 0.001); however, all-cause mortality did not differ significantly (14.1% vs. 7.6%, p = 0.132). For patients with SHPT, PTX helps prevent cardiovascular events through normalizing biochemical variables, according to recommended guidelines. PTX should be considered before cinacalcet treatment to prevent new cardiovascular events. Early PTX for appropriate patients can help prevent immediate postoperative complications and mortality.

Controversies in the Management of Secondary Hyperparathyroidism in Chronic Kidney Disease

Secondary hyperparathyroidism is a frequent complication of chronic kidney disease that begins early in the course of renal insufficiency as an adaptive response to maintain mineral homeostasis. This complex disorder affects the bone, leading to an increase in fracture risk and is associated with increased risks of vascular calcification and mortality. PURPOSE OF REVIEW: In this review, we examine the different strategies available to manage secondary hyperparathyroidism. Particularly, we focus on the adequate control of serum phosphorus by restricting intake and the use of phosphate binders, correction of hypocalcemia while minimizing calcium burden, and reduction in PTH levels through the use of vitamin D sterols and calcimimetics. RECENT FINDINGS: It was observed that although numerous agents directed at the correction of these abnormalities have demonstrated effectiveness on biochemical markers, there is still a relative scarcity of studies demonstrating treatment effectiveness as measured by hard clinical outcomes. In addition, most agents have side effects that may limit their use, even in patients in which the treatment has demonstrated efficacy in controlling these parameters. There is still controversy as to what therapeutic regimens to choose for a particular patient and what parameter should be used to follow their effects, including outcomes, side effects, pill burden, and costs, among others. In the present article, we analyze controversial aspects of the different therapeutic agents available. Although many tools and regimens are available, no one by itself is enough for an adequate management of the patient. But rather, combined therapy and individualization of approaches are recommended for better results. We suggest that new studies analyzing the effectiveness of therapeutic approaches to the management of secondary hyperparathyroidism should be directed not only to controlling parathyroid hormone levels but also to the evaluation of long-term outcomes, based on modification of morbidity, mortality, and end organ impact, while reducing side effects and controlling costs, among others.

Parathyroid hormone independently predicts fracture, vascular events, and death in patients with stage 3 and 4 chronic kidney disease

Doctors do not know whether treatment of high parathyroid hormone levels is linked to better outcomes in their patients with kidney disease. In this study, lower parathyroid hormone levels at baseline were linked to lower risk of fracture, vascular events, and death in people with kidney disease.

PURPOSE

Chronic kidney disease (CKD) affects ~ 20% of older adults, and secondary hyperparathyroidism (HPT) is a common condition in these patients. To what degree HPT predicts fractures, vascular events, and mortality in pre-dialysis CKD patients is debated. In stage 3 and 4 CKD patients, we assessed relationships between baseline serum PTH levels and subsequent 10-year probabilities of clinical fractures, vascular events, and death.

METHODS

We used Marshfield Clinic Health System electronic health records to analyze data from adult CKD patients receiving care between 1985 and 2013, and whose PTH was measured using a second-generation assay. Covariates included PTH, age, gender, tobacco use, vascular disease, diabetes, hypertension, hyperlipidemia, obesity, GFR, and use of osteoporosis medications.

RESULTS

Five thousand one hundred eight subjects had a mean age of 68 ± 17 years, 48% were men, and mean follow-up was 23 ± 10 years. Fractures, vascular events, and death occurred in 18%, 71%, and 56% of the cohort, respectively. In univariate and multivariate models, PTH was an independent predictor of fracture, vascular events, and death. The hazards of fracture, vascular events and death were minimized at a baseline PTH of 0, 69, and 58 pg/mL, respectively.

CONCLUSIONS

We found that among individuals with stage 3 and 4 CKD, PTH was an independent predictor of fractures, vascular events, and death. Additional epidemiologic studies are needed to confirm these findings. If a target PTH range can be confirmed, then randomized placebo-controlled trials will be needed to confirm that treating HPT reduces the risk of fracture, vascular events, and death.

Unusual recurrent renal secondary hyperparathyroidism caused by hyperplastic autograft with supernumerary parathyroid adenoma: A case report

RATIONALE

Secondary hyperparathyroidism (SHPT) is often complicated with chronic renal failure. Though the total parathyroidectomy (TPTX) with forearm autotransplantation (FAT) has been commonly used to treatment refractory renal SHPT, the recurrence of SHPT is not infrequent, resulting from hyperplastic autograft, remnant parathyroid tissues, and supernumerary parathyroid gland (SPG).

PATIENT CONCERNS

A 67-year-old man undergoing TPTX+FAT 4 years previously for renal SHPT, who received regular hemodialysis with active vitamin D supplements of Rocaltrol treatment postoperatively, was admitted to our hospital with progressively elevated serum intact parathyroid hormone (iPTH) from 176 to 1266 pg/mL for 8 months and bilateral ankle joints pain for 1 month. Tc-sestamibi dual-phase imaging with single positron emission tomography (SPECT)/computed tomography (CT) revealed a nodule in suprasternal fossa, besides a nodule in autografted site, accompanied with intense radioactivity.

DIAGNOSIS

Recurrent SHPT was easily diagnosed based on previous medical history, painful joints, increased serum iPTH level and positive findings of Tc-sestamibi imaging. Routine postoperative pathology showed that the nodules were consistent with an adenomatoid hyperplasic autograft and a supernumerary parathyroid adenoma in suprasternal fossa, respectively.

INTERVENTIONS

Reoperation for removing nodules in suprasternal fossa and autografted site was performed 1 month later. Then regular hemodialysis 3 times a week with Rocaltrol was continued.

OUTCOMES

During 12 months of follow-up, the joints pain improved obviously and the serum iPTH level ranged from 30.1 to 442 pg/mL.

LESSONS

Although rare, recurrent renal SHPT may be caused by a coexistence of both hyperfunctional autograft and SPG after TPTX+FAT. The Tc-sestamibi parathyroid imaging with SPECT/CT is helpful to locate the culprits of recurrent renal SHPT before reoperation. To prevent recurrence of renal SHPT, the present initial surgical procedures should be further optimized in patient on permanent hemodialysis.

Rationale for Raising Current Clinical Practice Guideline Target for Serum 25-Hydroxyvitamin D in Chronic Kidney Disease

BACKGROUND

Vitamin D repletion is recommended for secondary hyperparathyroidism (SHPT) and associated vitamin D insufficiency (VDI) in chronic kidney disease (CKD), but optimal levels of serum total 25-hydroxyvitamin D remain undefined. Clinical practice guidelines target sufficiency, whereas recent data indicate that higher levels are required to control the elevation of intact parathyroid hormone (iPTH) as CKD advances. This secondary analysis of 2 randomized controlled trials seeks to identify the minimum level of mean serum 25-hydroxyvitamin D required to control SHPT arising from VDI in stage 3 or 4 CKD.

METHODS

Adult subjects (n = 429) with SHPT, VDI, and stage 3 or 4 CKD were stratified by stage and treated daily with either extended-release calcifediol (ERC) or placebo in 2 identical, parallel, randomized, double-blind studies. After treatment for 26 weeks, all subjects were ranked by the level of serum total 25-hydroxyvitamin D and divided into quintiles in order to examine the relationships between the degree of vitamin D repletion and the associated changes in plasma iPTH, serum bone turnover markers, calcium, phosphorus, intact fibroblast growth factor 23 (FGF23) and vitamin D metabolites, estimated glomerular filtration rate (eGFR), and urine calcium:creatinine (Ca:Cr) ratio.

RESULTS

Progressive increases in serum 1,25-dihydroxyvitamin D and reductions in plasma iPTH and serum bone turnover markers were observed as mean posttreatment serum 25-hydroxyvitamin D rose from 13.9 ng/mL (in Quintile 1) to 92.5 ng/mL (in Quintile 5), irrespective of CKD stage. Mean serum calcium, phosphorus and FGF23, eGFR, and urine Ca:Cr ratio (collectively "safety parameters") did not significantly change from Quintile 1. Suppression of iPTH and bone turnover markers was not observed until serum 25-hydroxyvitamin D rose to at least 50.8 ng/mL (Quintile 3).

CONCLUSION

ERC therapy produced exposure-dependent reductions in plasma iPTH and bone turnover markers only when mean serum total 25-hydroxyvitamin D reached at least 50.8 ng/mL, indicating that current targets for vitamin D repletion therapy in CKD are too low. Gradual elevation of mean serum 25-hydroxyvitamin D to 92.5 ng/mL was not associated with significant adverse changes in safety parameters.

Avascular osteonecrosis in kidney transplant recipients: Risk factors in a recent cohort study and evaluation of the role of secondary hyperparathyroidism

Avascular osteonecrosis (AVN) is a bone complication that indicates poor functional prognosis. Modern immunosuppressive and steroid-sparing drugs have significantly lowered the occurrence of AVN after kidney transplantation (KT). However, recent data on its incidence rates and risk factors are lacking. Using a large, recent cohort, we sought to investigate AVN incidence and risk factors, with a special focus on mineral and bone disorders. We conducted a cohort study in 805 patients who underwent KT between 2004 and 2014. AVN was identified in 32 patients (4%): before KT in 15 (1.8%) and after KT in 18 (2.2%) cases, including one patient with both. In the group with post-KT AVN, the median time intervals from KT to 1) first symptoms and 2) AVN diagnosis were 12 months [1–99] and 20 months [4–100], respectively. Being overweight/obese, having pre-transplant diabetes or hyperparathyroidism at transplantation, developing acute rejection, and receiving higher cumulative corticosteroid doses were associated with AVN occurrence. Multivariate analysis revealed that BMI ≥ 26 kg/m² and higher cumulative corticosteroid doses were predictive of AVN. In conclusion, overweight/obesity is a strong risk factor for AVN. Despite a low maintenance dose, the use of corticosteroids—mostly for treatment of acute rejection—remains an independent risk factor.

Fibroblast Growth Factor 23 Genotype and Cardiovascular Disease in Patients Undergoing Hemodialysis

BACKGROUND

Elevated serum concentrations of fibroblast growth factor 23 (FGF23) are associated with cardiovascular mortality in patients with chronic kidney disease and those undergoing dialysis.

OBJECTIVES

We tested the hypotheses that polymorphisms in FGF23, its co-receptor alpha-klotho (KL), and/or FGF23 receptors (FGFR) are associated with cardiovascular events and/or mortality.

METHODS

We used 1,494 DNA samples collected at baseline from the Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events Trial, in which patients were randomized to the calcimimetic cinacalcet or placebo for the treatment of secondary hyperparathyroidism. We analyzed European and African Ancestry samples separately and then combined summary statistics to perform a meta-analysis. We evaluated single-nucleotide polymorphisms (SNPs) in FGF23, KL, and FGFR4 as the key exposures of interest in proportional hazards (Cox) regression models using adjudicated endpoints (all-cause and cardiovascular mortality, sudden cardiac death, and heart failure [HF]) as the outcomes of interest.

RESULTS

rs11063112 in FGF23 was associated with cardiovascular mortality (risk allele = A, hazard ratio [HR] 1.32, meta-p value = 0.004) and HF (HR 1.40, meta-p value = 0.007). No statistically significant associations were observed between FGF23 rs13312789 and SNPs in FGFR4 or KL genes and the outcomes of interest.

CONCLUSIONS

rs11063112 was associated with HF and cardiovascular mortality in patients receiving dialysis with moderate to severe secondary hyperparathyroidism.

Secondary and Tertiary Hyperparathyroidism

Secondary hyperparathyroidism (SHP) is a frequent complication of kidney diseases. At variance with all the other forms of SHP, which are compensatory conditions, renal SHP has many pathogenetic peculiarities, which have been only in part defined. Furthermore, in the long course of chronic kidney diseases (CKD), SHP sometimes transforms into a hypercalcemic condition resembling the autonomous form of hyperparathyroidism (tertiary hyperparathyroidism; THP). The clinical consequences of SHP in CKD patients are manifold, encompassing not only bone and mineral disorders, but also other metabolic and organic changes which frequently burden these patients. Although the medical therapeutic tools have substantially increased in number and improved in their efficacy in recent decades, we have as yet no demonstration of a clear benefit regarding the major clinical outcomes. Furthermore, some of these patients, particularly when the autonomous THP develops, still require a surgical approach.

Bone metabolism, density, and geometry in postmenopausal women with vitamin D insufficiency: a cross-sectional comparison of the effects of elevated parathyroid levels

Increased levels of parathyroid hormone (PTH) may have adverse effects on bone health. In a cross-sectional design, we investigated this hypothesis among 102 postmenopausal vitamin D insufficient women. Elevated PTH was associated with altered bone geometry, decreased bone mineral density in the spine, and increased bone turnover.

INTRODUCTION

In vitamin D insufficiency, elevated parathyroid hormone (PTH) levels may contribute to adverse effect on bone. We assessed effects of PTH responses to vitamin D insufficiency on bone metabolism, density, and geometry.

METHODS

Using a cross-sectional design, we investigated 102 healthy postmenopausal women with low 25-hydroxy-vitamin D (< 50 nmol/L) levels, who had either secondary hyperparathyroidism with elevated PTH levels (> 6.9 pmol/L, N = 51) or normal PTH levels (N = 51). Bone mineral density (BMD) and bone geometry were assessed by Dual-Energy X-ray absorptiometry (DXA), quantitative computed tomography (QCT) and high-resolution peripheral QCT (HRpQCT) scans. Bone metabolism was assessed by biochemistry including bone turnover markers.

RESULTS

Levels of 25(OH)D were 38 (IQR 31-45) nmol/L with no differences between groups. PTH levels were 8.5 (IQR 7.5-9.5) in women with SHPT and 5.2 (4.4-6.6) pmol/L in women with normal PTH (p < 0.001). BMI and eGFR did not differ between groups. SHPT was associated with lower total- and trabecular bone area, lower cortical perimeter, and increased cortical area in tibia and radius. SHPT was associated with a lower weight-adjusted BMD at the lumbar spine (p < 0.05). High compared to normal PTH levels were associated with significantly lower plasma levels of 1,25(OH)₂D, phosphate, but higher levels of osteocalcin and borderline higher levels of CTx. PTH correlated to osteocalcin and CTx.

CONCLUSIONS

High PTH levels are associated with altered bone geometry, increased bone turnover, and reduced BMD at the spine. Whether an increased cortical thickness with a lower trabecular volume is an effect of PTH or not needs further elucidations.

[Hyperphosphatemia in dialysis: which binder?]

Several studies have evidenced the association between high serum phosphorus concentrations and adverse events especially in patients on dialysis. Recent K-DIGO guidelines suggest lowering elevated phosphate levels toward the normal range. This goal should be achieved by combining dietary counseling, optimizing dialysis procedures and prescribing phosphate binders. Despite the availability of several binders, the "ideal" phosphate binder that combines high efficacy, low pills burden, minimal side effects and low cost is still not available. In clinical practice it is crucial to reach a high patient's compliance to therapy. The pill burden is the most relevant factor contributing to low compliance. This is the case of phosphate binder therapy that represents almost 50% of total pills prescribed to patients on dialysis. It has been evidenced an association between pills of phosphate binder and poor control of phosphorus and PTH. In recent years sucroferric oxyhydroxide is available as a new phosphate binder. Its peculiarity is an high phosphate binding capability that requires prescription of low number of pills per day. This characteristic has been confirmed by several randomized controlled trials. These trials have also evidenced that sucroferric oxyhydroxide may cause some gastrointestinal side effects. There is an ongoing study to confirm in "the real world" the incidence of side effects reported by controlled trials.

Pharmacodynamics of evocalcet for secondary hyperparathyroidism in Japanese hemodialysis patients

BACKGROUND

This study investigated the pharmacokinetics, pharmacodynamics, and safety of multiple doses of evocalcet in Japanese secondary hyperparathyroidism (SHPT) patients receiving hemodialysis.

METHODS

In this multicenter, open-label study, conducted between August 2013 and March 2014, 27 patients received multiple doses of 1 and 4 mg evocalcet for 14 days, followed by an extension period of multiple doses of 8 and 12 mg evocalcet for 7 days using an intra-patient dose escalation protocol. Pharmacodynamic parameters consisted of measurement of intact parathyroid hormone (PTH), serum-corrected calcium, serum phosphorus and intact fibroblast growth factor 23 concentrations. Safety was assessed by analysis of adverse events.

RESULTS

Plasma evocalcet levels reached steady state 3 days after the first day of administration. Pharmacodynamic analyses showed that evocalcet effectively reduced intact PTH and serum-corrected calcium levels. Adverse events (AEs) occurred in 29.6 and 62.5% of patients receiving multiple doses of 1 or 4 mg, respectively. The AE 'blood calcium decreased' occurred in eight patients (33.0%) after multiple doses of 4 mg. All events were mild, except for one patient with a moderate AE (abnormal liver function) and one patient with a severe adverse drug reaction (blood calcium decreased).

CONCLUSION

Multiple doses of evocalcet reduced intact PTH levels with a concomitant decrease in serum calcium levels. Evocalcet was well tolerated in SHPT patients receiving hemodialysis.

Association of Anabolic Effect of Calcitriol with Osteoclast-Derived Wnt 10b Secretion

Canonical Wnt (Wingless/Integrated) signaling is crucial in bone development and the Wnt ligand can promote osteoblast differentiation from mesenchymal progenitor cells. Calcitriol, an active vitamin D3, is used clinically for treatment of secondary hyperparathyroidism (SHPT) in chronic kidney disease (CKD) patients. The bone effects of calcitriol in SHPT remains uncertain. We hypothesized that calcitriol improves bone mass by suppressing osteoclast activity, and simultaneously promoting Wnt ligand secretion. We designed a cross-sectional study in maintenance hemodialysis patients to explore the effects of calcitriol on different bone turnover markers and specifically emphasized the Wnt 10b levels. Then, we explored the source of Wnt 10b secretion by using osteoclasts and osteoblasts treated with calcitriol in cell culture studies. Finally, we explored the effects of calcitriol on bone microarchitectures in CKD mice, using the 5/6 nephrectomy CKD animal model with analysis using micro-computed tomography. Calcitriol promoted the growth of both trabecular and cortical bones in the CKD mice. Wnt 10b and Procollagen 1 N-terminal Propeptide (P1NP) significantly increased, but Tartrate-resistant acid phosphatase 5b (Trap 5b) significantly decreased in the calcitriol-treated maintenance hemodialysis patients. Calcitriol enhanced Wnt 10b secretion from osteoclasts in a dose-dependent manner. Treatment of SHPT with calcitriol improved the bone anabolism by inhibiting osteoclasts and promoting osteoblasts that might be achieved by increasing the Wnt 10b level.

Morbidity in parathyroid surgery for renal disease is under reported: a comparison of outcomes with primary hyperparathyroidism

Introduction Parathyroidectomy is considered to be a safe procedure with low morbidity. However, while this is true for primary hyperparathyroidism, whether it applies to tertiary disease is not so well documented. The aim of this study was to assess the morbidity of surgery for tertiary hyperparathyroidism compared with primary disease and to establish whether there are predictive factors for poor outcomes. Methods Data for patients subjected to parathyroidectomy during the period 2007-2015 were retrospectively analysed from a prospectively collected database. Patient age, sex, American Society of Anesthesiologists (ASA) score, renal status, extent of operation and indications for surgery were examined. The complication and mortality rate were compared and independent predictors of outcome were examined. Results A total of 1079 patients were scheduled for a parathyroidectomy during the study period of whom 158 for renal related hyperparathyroidism (renal group) and 921 for primary disease (non-renal group). There was a significantly higher complication rate in the renal parathyroid group, including a higher mortality (1.3% vs 0.1%, P = 0.011), overall complication rate (7.0% vs 2.3%, P = 0.001), surgery related complication rate (4.4% vs 1.7%, P = 0.03) and systemic complication rate (2.5% vs 0.4%, P = 0.005). In patients with ASA score ≤ 2 reoperative surgery (OR 9.25, 95% confidence interval, CI 1.41-60.75), male sex (OR 4.12, 95% CI 1.46-11.63) and renal impairment were (OR 5.86, 95% CI 1.65-20.78) were predictors of worse outcomes. In patients with ASA score ≥3 renal impairment, in addition to other variables, were not predictors of complications. Conclusions Parathyroidectomy in renal-related disease is associated with a significantly higher risk of morbidity and mortality compared with primary hyperparathyroidism.

Parathyroidectomy in the Management of Secondary Hyperparathyroidism

Secondary hyperparathyroidism develops in CKD due to a combination of vitamin D deficiency, hypocalcemia, and hyperphosphatemia, and it exists in nearly all patients at the time of dialysis initiation. There is insufficient data on whether to prefer vitamin D analogs compared with calcimimetics, but the available evidence suggests advantages with combination therapy. Calcium derangements, patient adherence, side effects, and cost limit the use of these agents. When parathyroid hormone level persists >800 pg/ml for >6 months, despite exhaustive medical interventions, monoclonal proliferation with nodular hyperplasia is likely present along with decreased expression of vitamin D and calcium-sensing receptors. Hence, surgical parathyroidectomy should be considered, especially if concomitant disorders exist, such as persistent hypercalcemia or hyperphosphatemia, tissue or vascular calcification including calciphylaxis, and/or worsening osteodystrophy. Parathyroidectomy is associated with 15%-57% greater survival in patients on dialysis, and it also improves hypercalcemia, hyperphosphatemia, tissue calcification, bone mineral density, and health-related quality of life. The parathyroidectomy rate in the United States declined to approximately seven per 1000 dialysis patient-years between 2002 and 2011 despite an increase in average parathyroid hormone levels, reflecting calcimimetics introduction and uncertainty regarding optimal parathyroid hormone targets. Hospitalization rates are 39% higher in the first postoperative year. Hungry bone syndrome occurs in approximately 25% of patients on dialysis, and profound hypocalcemia requires high doses of oral and intravenous calcium along with calcitriol supplementation. Total parathyroidectomy with autotransplantation carries a higher risk of permanent hypocalcemia, whereas risk of hyperparathyroidism recurrence is higher with subtotal parathyroidectomy. Given favorable long-term outcomes from observational parathyroidectomy cohorts, despite surgical risk and postoperative challenges, it is reasonable to consider parathyroidectomy in more patients with medically refractory secondary hyperparathyroidism.

Secondary hyperparathyroidism among Nigerians with chronic kidney disease

BACKROUND

Secondary hyperparathyroidism (SHPT) is a manifestation of chronic kidney disease mineral bone disorder (CKD-MBD). SHPT is common in patients with chronic kidney disease (CKD) and is associated with significant morbidity and mortality.

METHODS

A cross- sectional descriptive study involving 230 patients with CKD.

RESULTS

The mean age of the study population was 44.17±15.24 years. The median intact parathyroid hormone and alkaline phosphatase levels were 96pg/ml (range 4-953pg/ml) and 88 iu/l (range 10-800 iu/l) respectively. The mean (with standard deviation) calcium, serum phosphate, calcium phosphate product and haemoglobin levels were 2.22±0.29mmol/l, 1.8±0.62mmol/l, 3.94±1.42mmol2/l2 and 9.90±1.87g/dl respectively. Majority of patients had advanced CKD with 70.3% of patients in stage G5. The prevalence rates of SHPT, hypocalcaemia, hyperphosphataemia, elevated alkaline phosphatase and elevated calcium phosphate product were 55.2%, 34.8%, 66.1%, 42.2% and 25.2% respectively.Univariate analysis revealed that SHPT was associated with hypocalcaemia, hyperphosphataemia, elevated alkaline phosphatase, proteinuria, anaemia, hypertension, left ventricular hypertrophy and stage of kidney disease; being worse with advancing kidney disease. Independently associated with SHPT were hypocalcaemia (OR=4.84), hyperphosphataemia (OR=3.06), and elevated alkaline phosphatase (OR=2.04).

CONCLUSION

The prevalence of SHPT in CKD is high, occurs early and is independently associated with hypocalcaemia, hyperphosphataemia and elevated alkaline phosphatase. The prevalence of SHPT also increases with worsening renal function.

Dietary Changes Involving Bifidobacterium longum and Other Nutrients Delays Chronic Kidney Disease Progression

BACKGROUND

Recent studies suggest that prebiotic and/or probiotic treatments ameliorate kidney function in humans and animals by improving the gut environment. However, the gut microbiota and kidney disease interactions remain to be determined. This study investigated whether synbiotics modulate the gut microbiota and ameliorate kidney function using a rat model of chronic kidney disease (CKD). As uremic toxins are associated with CKD-related mineral and bone disorder, the secondary aim was to evaluate the relationship between synbiotics and secondary hyperparathyroidism (SHPT).

METHODS

5/6 nephrectomy (Nx) rats were developed as the CKD model. Sham-operated (sham) rats were used as the control. To investigate the effectiveness of prebiotics (glutamine, dietary fiber, and oligosaccharide) and probiotics (Bifidobacterium longum strain; GFOB diet), rats were randomly assigned to 4 groups: Nx group fed the GFOB diet (n = 10); Nx group fed the control (CON) diet (n = 10); sham group fed the GFOB diet (n = 5); and sham group fed the control diet (n = 5). Blood, feces, and kidney samples were collected and analyzed.

RESULTS

Serum creatinine (Cre) and blood urea nitrogen in the Nx GFOB group were significantly lower than those in the Nx CON group. Serum indoxyl sulfate in the Nx GFOB group was lower than that in the Nx CON group, and significantly correlated with serum Cre. Inorganic phosphorus and intact parathyroid hormone in the Nx GFOB group were significantly lower than those in the Nx CON group.

CONCLUSION

Improving the gut environment using synbiotics ameliorated kidney function and might be a pharmacological treatment for SHPT without any serious adverse events.

Multiple vertebral fractures sustained 5 months after Roux-en-Y gastric bypass: a case report

INTRODUCTION

We report a case of a patient sustaining multiple simultaneous vertebral fractures 5 months after Roux-en-Y gastric bypass (RYGB) surgery. Obesity is associated with increased rates of morbidity and mortality and obesity rates globally continue to rise. Bariatric surgical procedures are successful in inducing sustained weight loss with many improved health outcomes. Potential complications include nutritional deficiencies and adverse effects on bone mineral metabolism with increased rates of fracture.

CASE STUDY

We have recently cared for a 40-year-old female who sustained multiple vertebral fractures after bending forwards, occurring only 5 months after she underwent RYGB surgery, with post-operative weight loss of 55 kg. Blood tests performed several months after the fractures occurred revealed she had biochemical secondary hyperparathyroidism with low serum vitamin D levels.

DISCUSSION

It has been previously demonstrated that RYGB surgery is associated with an increased incidence of fractures, and with reduction in bone mineral density. Patients undergoing bariatric surgery are frequently vitamin D deficient pre-operatively and show variable responses to vitamin D supplementation in the post-operative period. With particular reference to the RYGB procedure, there is evidence from several studies that bone mineral density is reduced at 12 and 24 post-operative months. To the best of our knowledge, this case may be the first time that multiple vertebral fractures have been documented so soon after weight loss surgery. It therefore highlights the growing conclusion that early consideration must be given to the maintenance of bone health in patients undergoing weight loss surgery.

[Update 2017 of the KDIGO guidelines on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). What are the real changes?]

Guidelines for the assessment, diagnosis and therapy of the alterations that characterize the CKD-MBD are an important support in the clinical practice of the nephrologist. Compared to the KDIGO guidelines published in 2009, the 2017 update made changes on some topics on which there was previously no strong evidence both in terms of diagnosis and therapy. The recommendations include the diagnosis of bone anomalies in CKD-MBD and the treatment of mineral metabolism abnormalities with particular regard to hyperphosphataemia, calcium levels, secondary hyperparathyroidism and anti-resorptive therapies. The Italian Study Group on Mineral Metabolism, in reviewing the 2017 recommendations, aimed to assess the weight of the evidence that led to this update. In fact, on some topics there has not been a substantial difference on the degree of evidence compared to the previous guidelines. The Italian Study Group emphasizes the points that may still reserve critical issues, including interpretation, and invites an evaluation that is articulated and personalized for each patient.

Parathyroid Cancer in a Hemodialysis Patient: A Case Report

An extremely rare case of parathyroid cancer in a hemodialysis patient is presented here. A 69-year-old man was operated on for secondary hyperparathyroidism due to chronic renal failure. A locally invasive tumor of the right inferior parathyroid gland and enlargement of the other three parathyroid glands were found during bilateral neck exploration. Surgical management consisted of en bloc resection of the right inferior parathyroid gland with the right thyroid lobe and part of a sternothyroid muscle along with subtotal parathyroidectomy of the three enlarged parathyroid glands. Histological examination of the resected tumor provided evidence of a parathyroid cancer in the right inferior parathyroid gland. Nodular hyperplasia was confirmed histologically in the other three glands. With less than 20 previous cases described in the literature, parathyroid cancer is a very rare condition in hemodialysis patients.

Obesity, Bariatric Surgery, and Vitamin D

The high prevalence of obesity is a worldwide problem associated with multiple comorbidities, including cardiovascular diseases. Vitamin D deficiency with secondary hyperparathyroidism is common in obese individuals and can be aggravated after bariatric surgery. Moreover, there is no consensus on the optimal supplementation dose of vitamin D in postbariatric surgical patients. We present new data on the variability of 25(OH)D response to supplementation in postmenopausal obese women. It is important to recognize and treat vitamin D deficiency before bariatric surgery to avoid postoperative complications, such as metabolic bone disease with associated high fracture risk. The objective of this article is to discuss the bone metabolism consequences of vitamin D deficiency after bariatric surgery.

Secondary Hyperparathyroidism in HIV-Infected Patients in Central Europe

Secondary hyperparathyroidism (sHPT) might be a contributor to increased risk of osteoporosis in adult HIV patients but there is little data available on this issue in this particular population. The aim of the study was to investigate the prevalence of sHPT in an HIV-infected population with normal kidney function and to evaluate its risk factors in HIV patients. This cross-sectional study was carried out in a single HIV center in Germany using routine data from patients with normal kidney function attending the clinic between January 1st and December 31st, 2016. In total, 1263 patients were included [998 (79.0%) male, median age 48 (IQR 38-54) years]. In 214 patients (16.9%) elevated PTH levels with low or normal calcium levels were found. Multivariate logistic regression modeling showed significant associations with elevated PTH for African ethnicity [OR: 2.12 (95% CI: 1.42-3.16); p<0.001], low 25-hydroxyvitamin D levels [OR: 1.82 (95% CI: 1.32-2.51); p<0.001], low calcium levels [OR 1.69 (95% CI: 1.22-2.33); p=0.001], and use of tenofovir disoproxil fumarate [OR 2.33 (95% CI: 1.62-3.36); p<0.001]. Additional to common risk factors like vitamin D insufficiency and hypocalcemia, we found a significant association between the use of TDF and sHPT. Prospective data are needed to ascertain whether PTH-mediated bone loss is the underlying mechanism of TDF bone-toxicity. Additional screening of PTH even in HIV-infected patients with normal or low calcium levels may help to identify patients at increased risk of bone mineral density loss.

Clinical predictor of postoperative hyperkalemia after parathyroidectomy in patients with hemodialysis

OBJECTIVE

Hyperkalaemia is one of the most common reasons for patients requiring emergency treatment. This study is to investigate the risk factors of postoperative hyperkalemia in renal failure patients undergoing parathyroidectomy with autotransplantation (PTXa).

METHODS

One hundred and eight patients [ 54 men and 54 women; age, 45.1 ± 11.1 years (mean ± SD)] with secondary hyperparathyroidism undergoing parathyroidectomy with autotransplantation were involved in this study. Laboratory chemistries (hemoglobin, fasting blood glucose, serum calcium level, alkaline phosphatase, phosphorus, parathyroid hormone) were measured before surgery. Serum potassium level was obtained before surgery and at 0 h after surgery.

RESULTS

Serum potassium level increased in 108 patients after surgery (P < 0.05). Sixteen patients (14.8%) potassium levels rose more than 6.0 mmol/L after parathyroidectomy with autotransplantation. Age and preoperative serum potassium level were significantly negative correlated with postoperative serum potassium level. Correlation analysis and receiver operating characteristic curve method confirmed that use of the preoperative serum potassium level was the primary predictor of postoperative hyperkalemia. The cutoff point for preoperative serum potassium level was 4.40 mmol/L, according to the Youden index of the receiver operating characteristic curve.

CONCLUSIONS

Preoperative serum potassium increased after parathyroidectomy with autotransplantation in patients with secondary hyperparathyroidism. The preoperative serum potassium level could help the surgeon to predict postoperative hyperkalemia in case of emergency dialysis following surgery.

Optimizing Efficacy of Quick Parathyroid Hormone Determination in the Operating Theater

The usefulness of intraoperative parathyroid hormone (PTH) monitoring has been extensively documented in primary hyperparathyroidism (HPT), whereas few data have been published on its use in reoperations or in secondary and tertiary HPT. We report our initial experience with a rapid (12 min response) PTH immunochemiluminometric assay performed in the operating room during surgery in 12 patients with primary HPT, 16 end-stage renal disease patients with secondary HPT and five kidney transplanted subjects with tertiary HPT. Blood samples were taken at baseline, within 10 min after resection and subsequently at various intervals whenever needed. The mean PTH levels before and after parathyroidectomy were 230.5 pg/mL (range 69–842) and 47.3 pg/mL (range 5–184), respectively, in primary HPT, 855.0 pg/mL (416–1655) and 202.2 pg/mL (53–440) in secondary HPT, and 205.6 pg/mL (116–301) and 45.4 pg/mL (18–97) in tertiary HPT. All patients but one had a significant percentage decline from pre-excision values (mean 76.9%, 76.0%, and 76.1% in primary, secondary and tertiary HPT, respectively). While a reduction of more than 50% was observed in 30 out of 33 patients after the first intraoperative sampling, additional measurements were performed in 10 cases. On-site PTH monitoring with this user-friendly and reliable system has proved helpful in targeting PTH tests to give the surgeon a rapid and accurate assessment of the intervention. The development of optimal PTH sequence strategies with decision-focused analytical and clinical limits will improve the efficacy of “point-of-care” PTH assay and resource utilization.

Relationships of serum 25-hydroxyvitamin D, ionized calcium and parathyroid hormone after obesity surgery

OBJECTIVE

The high prevalence of secondary hyperparathyroidism (SHPT) after obesity surgery is a concern for long-term bone health. Limited knowledge exists about optimal vitamin D and suppression of parathyroid hormone (PTH) after these procedures. The aim of this study was to investigate the prevalence of SHPT and its relation to vitamin D status.

DESIGN

A cross-sectional study at Oslo University Hospital, Norway.

PATIENTS

A total of 502 consecutive patients, age 22-64 years, attending 2-year follow-up after Roux-en-Y gastric bypass.

MEASUREMENTS

A serum intact PTH >7.0 pmol/L in the absence of elevated serum ionized calcium (iCa) was considered as SHPT. Vitamin D status was defined by serum concentrations of 25-hydroxyvitamin D (S-25(OH)D).

RESULTS

Altogether, 171 patients (34%) had SHPT. The prevalence of SHPT varied across the range of S-25(OH)D (P < 0.001), being highest (71%) with S-25(OH)D < 25 nmol/L. Compared with S-25(OH)D < 50 nmol/L, the prevalence of SHPT was lower with S-25(OH)D ≥ 50 nmol/L (29.0%; RR = 0.64 (95%-CI:0.50-0.81)) and S-25(OH)D ≥ 75 nmol/L (27.7%; RR = 0.61 (95%-CI:0.44-0.84)). S-25(OH)D ≥ 100 nmol/L was associated with the lowest PTH and the lowest prevalence of SHPT (16.0%; RR = 0.35 (95%-CI:0.14-0.88) compared with S-25(OH)D < 50 nmol/L) and the most normal calcium distribution. These associations were most pronounced with iCa in the lower range. A synergistic association was found for S-25(OH)D and iCa on SHPT.

CONCLUSIONS

Vitamin D deficient patients had the highest prevalence of SHPT 2 years after gastric bypass. PTH and the prevalence of SHPT were notably lower with S-25(OH)D ≥ 100 nmol/L, compared with lower target levels.

[Total parathyroidectomy, autoimplant and cryopreservation for the treatment of hyperparathyroidism of renal origin in children and young adults]

OBJECTIVES

To describe our initial experience in the treatment of hyperparathyroidism (HPP) of renal cause using total or subtotal parathyroidectomy, autoimplant and cryopreservation in pediatric patients. Secondary HPP is the increased function of the parathyroid hormone (PTH) due to an abnormal phosphocalcic metabolism in patients with chronic renal failure (CRF). This situation produces increased bone resorption resulting in osteodystrophy and endovascular calcifications. Surgical treatment is aimed to diminish the level of PTH in CRF patients, to avoid HPP complications.

METHODS AND MATERIALS

Descriptive, monocentric and retrospective study of a case series of patients with secondary and tertiary hyperparathyroidism, who went through total or subtotal parathyroidectomy, autoimplant and cryopreservation between 2009 and 2016. We analyzed the following variables: age, calcemia, PTH, phosphatemia, alkaline phosphatase (ALP), follow-up and complications. The continuous variables are expressed in median and interquartile range or in mean and SD, according to their distribution. The categorical variables were expressed in percentages and frequencies (repeated sentence).

RESULTS

Number of patients included: 13. Mean age of the patients was 16.7 years old. Preoperative median calcium dosage was 9.1 mg/dl (IQR: 8.9-9.5). Median PTH was 2,600 pg/ml (IQR: 1,400 pg/ml to 2,785 pg/ml). Intraoperatory dosage of PTH reported a median drop of 86.6% in the first 15 minutes (IQR: 80.5-95.9). After the first 48 hours, median calcemia was 9 mg/dl (IQR: 7.7-9.4) and median PTH was 40 pg/ml (IQR: 20-113). We did not identify intraoperatory complications. In the immediate post operatory stage, mean IV calcium therapy was 4 days (SD: 2.39). Median time of follow-up was 18 months (IQR 9-36). Two patients had hungry bone syndrome and one patient had a recurrence of the pathology as remote post operatory complications. After a year, median calcemia, was 9 mg/dl (IQR: 7.6-9.3) and median PTH was 50 pg/ml (IQR: 28.5-108). The decrease in PTH and ALP were statistically significant with p value < 0.05.

CONCLUSION

In our study, total parathyroidectomy with auto implant is a safe and effective option for the treatment of secondary and tertiary hyperparathyroidism in pediatric patients. This could also prevent bone complications.

Facial Changes in Adult Uremic Patients on Chronic Dialysis: Possible Role of Hyperparathyroidism

Background

Uremic patients on regular dialytic treatment (RDT) are often affected by a complex metabolic syndrome leading to osteodystrophy. Bone changes are primarily due to high bone turn over, often combined with a mineralization defect leading to increased bone fractures and bone deformities. Although rarely considered, the craniofacial skeleton represents one of the peculiar targets of this complex metabolic disease whose more dramatic pattern is a form of leontiasis ossea. This complication, although described, has never been evaluated in depth nor quantitatively assessed. In order to assess facial deformities in uremic conditions and to understand the possible relation with hyperparathyroidism, we undertook a quantitative evaluation of soft facial structures in a cohort of uremic patients undergoing RDT.

Methods

The three-dimensional coordinates of 50 soft-tissue facial landmarks were obtained by an electromagnetic digitizer in 10 male and 10 female patients with chronic renal insufficiency aged 53–81 years, and in 34 healthy individuals of the same age, ethnicity and sex. Uremic patients were enrolled according to hyperparathyroid status (PTH < 300 pg/mL and PTH > 500 pg/mL). From the landmarks, facial distances, angles and volumes were calculated according to a geometrical face model.

Results

Overall, the uremic patients had significantly larger facial volumes than the reference subjects. The effect was particularly evident in the facial middle third (maxilla), leading to an inversion of the mandibular-maxillary ratio. Facial dimensions were increased in all three spatial directions: width (skull base, mandible, nose), length (nose, mandible), and depth (mid face, mandible). The larger maxilla was accompanied by a tendency to more prominent lips (reduced interlabial angle). Some of the facial modifications (nose, lips, mandible) were significantly related to the clinical characteristics of the patients (age, duration of renal insufficiency and PTH levels).

Conclusions

This report, the first in the literature, shows that facial structures of uremic patients are enlarged in comparison with matched normal subjects and that increased bone turnover could be responsible – at least in part – for facial bone changes.

Hyperphosphatemia in Dialysis Patients: The Therapeutic Role of Lanthanum Carbonate

Phosphate overload is a dramatic consequence in end-stage renal disease (ESRD) patients. Recent studies have well documented that abnormalities in mineral and bone metabolism in these patients are associated with increased cardiovascular morbidity and mortality. Elevated serum phosphate and calcium-phosphate product levels play an important role in the pathogenesis of secondary hyperparathyroidism and extra-skeletal calcification in dialysis patients. Furthermore, inorganic phosphate may cause vascular calcification directly through a real “ossification” of the tunica media in the vasculature of ESRD patients.

The “classical” treatment of secondary hyperparathyroidism and hyperphosphatemia in ESRD patients consists of either calcium- or aluminum-based phosphate binders and calcitriol administration. Unfortunately, this “old generation” therapy is not free of complications. This review paper suggests that new calcium- and aluminum-free phosphate binders, such as lanthanum carbonate, can be used to treat hyperphosphatemia and secondary hyperparathyroidism in ESRD patients.

Is There Association between Vitamin D Concentrations and Body Mass Index Variation in Women Submitted to Y-Roux Surgery?

OBJECTIVE

To evaluate vitamin D deficiency and body composition of women submitted to bariatric surgery and relate their body mass index variation after surgery to 25(OH)D concentrations.

METHOD

A cross-sectional and controlled study was performed including 49 obese adult volunteer women, submitted to Roux-en-Y gastric bypass (RYGB group).

COLLECTED DATA

Body mass index (BMI), self-declared ethnicity, economic condition, physical activity level, serum concentrations of 25-hydroxycholecalciferol (25(OH)D; radioimmunoassay), parathormone, and body composition by dual-energy X-ray absorptiometry (Hologic DXA-QDR-1000) were collected.

RESULTS

25(OH)D deficiency was found in 27 (55.1%) and 8 (21.1%) in the RYGB and control groups (p=0.002). Secondary hyperparathyroidism was more frequent in the RYGB group compared to the control group (15 (30.6%) versus 1 (2.6%); p=0.001). There was no relation of the studied variables and body composition with 25(OH)D deficiency. 25(OH)D concentrations were correlated (r=-0.531; p < 0.001) with BMI reduction, regardless of vitamin D supplementation.

CONCLUSION

Women submitted to bariatric surgery (RYGB) around three years ago had higher BMI and vitamin D deficiency, along with hyperparathyroidism, compared to the control group. There was no association between variables related to body composition and 25(OH)D concentrations. On the other hand, vitamin concentrations correlated negatively to BMI variation after undergoing surgery.

Treatment of secondary hyperparathyroidism with paricalcitol with or without cinacalcet in hemodialysis patients

INTRODUCTION    Secondary hyperparathyroidism (SHPT) is a common hormonal disorder associated with chronic kidney disease (CKD). The treatment of SHPT should lead to a reduction in parathormone concentrations by calcimimetics or active vitamin D administration and stabilization of calciumand phosphate metabolism. In the event of failure of conservative treatment, complete or partial parathyroid resection should be considered. OBJECTIVES    The aim of the study was to assess the beneficial effects of a combination treatment with paricalcitol and cinacalcet in comparison with paricalcitol alone. PATIENTS AND METHODS    A total of 64 hemodialyzed patients (mean [SD] age, 58 [16] years) with inadequate control of serum parathyroid hormone levels were treated with intravenous paricalcitol, while 16 patients simultaneously received oral cinacalcet. Laboratory tests (intact parathormone [iPTH], calcium, phosphorus) were performed on a monthly basis. In the study, iPTH, calium, phosphorus, and alkaline phosphatase levels were assessed at baseline and after 24 weeks of treatment with paricalcitol alone or in combination with cinacalcet. RESULTS    In both groups, a significant decrease in the iPTH level was observed. Although paricalcitol affects calcium levels, no hypercalcemia was observed. The combination treatment did not result in a significant lowering of iPTH levels in comparison with paricalcitol alone. CONCLUSIONS    Treatment of SHPT with intravenous paricalcitol in patients on hemodialysis is effective and has a good safety profile. The combination of paricalcitol and cinacalcet does not improve the outcomes. Moreover, the combined treatment does not affect calcium and phosphorus concentrations. The cost‑effectiveness of therapy should also be considered.

Total parathyroidectomy with forearm auto-transplantation improves the quality of life and reduces the recurrence of secondary hyperparathyroidism in chronic kidney disease patients

BACKGROUND

Our study aims to explore the effect of total parathyroidectomy (PTX) with forearm autotransplantation (FAT) on the quality of life and recurrence of secondary hyperparathyroidism (SHPT) in chronic kidney disease patients.

METHODS

A total of 104 chronic kidney disease patients with SHPT were enrolled and divided into the PTX (n = 62) and PTX + FAT (n = 42) groups. The operation efficacy was evaluated by analyzing preoperative and postoperative values, including levels of intact parathyroid hormone (iPTH), serum phosphorus, serum calcium, alkaline phosphatase (ALP), calcium-phosphorus product, signs and symptoms, and MOS 36-item short-form health survey (SF-36) scores. Moreover, complications and recurrences were followed up for 12 months after the operation. Binary logistic regression was to present the risk factors for the recurrence of chronic kidney disease patients with SHPT.

RESULTS

Compared with the preoperative values, the PTX and PTX + FAT groups showed decrease postoperative levels of iPTH, serum phosphorus, serum calcium, calcium-phosphorus product, bone pain, and skin pruritus at all time periods. The PTX and PTX + FAT groups demonstrated decreased ALP, fracture or deformity, and coronary artery calcification at 1 month, decreased short stature at 3 months after the operation but increased SF-36 score after operation. Compared with the PTX group, the level of iPTH decreased and the levels of serum calcium, calcium-phosphorus product increased at 3, 6, and 12 months after the operation in the PTX + FAT group. The levels of ALP, fracture or deformity, short stature, and SF-36 decreased separately at 1 week and 6 and 12 months after the operation, along with the decrease of coronary artery calcification and the recurrence rate, respectively, at 6 and 12 months after the operation in the PTX + FAT group when compared with those in the PTX group. Logistic regression analysis evidenced that the preoperative iPTH level, SF-36 score, and operation type were the risk factors for the recurrence of chronic kidney disease with SHPT.

CONCLUSION

Total PTX combined with FAT is more effective in improving the quality of life and reducing the recurrence of chronic kidney disease with SHPT than PTX alone.

Effect of Paricalcitol on Bone Density After Kidney Transplantation: Analysis of 2 Transplant Centers

INTRODUCTION

The Kidney Disease: Improving Global Outcomes Clinical Practice Guidelines on the management of bone disease in patients with chronic kidney disease recommend periodic measurement of serum calcium, phosphorus, vitamin D, and parathyroid hormone levels after kidney transplantation, with the frequencies that will vary according to the severity of bone disease and graft function. Paricalcitol, a selective vitamin D receptor activator, is indicated in the prevention and treatment of secondary hyperparathyroidism.

MATERIALS AND METHODS

We retrospectively evaluated the effect of treatment with paricalcitol among our kidney transplant recipients. We monitored the effect of paricalcitol on bone density; the plasma levels of parathyroid hormone, calcium, and phosphorus; and proteinuria and calciuria. Comparisons were made between these parameters before treatment and 12 months after treatment.

RESULTS

Eighty-eight kidney transplant recipients with a mean age at the time of transplantation of 47.1 ± 10.5 years were receiving paricalcitol. On average, paricalcitol was included into the treatment for 48 months from transplantation (median, 27 months). The patients had significantly improved bone density (P < .001), significantly lower parathyroid hormone levels (P < .001), and significantly decreased proteinuria (P = .02) after 12 months of treatment. During the treatment with paricalcitol, the immunosuppressive therapy, dose of prednisone, body mass index, and vitamin D levels had not significantly changed. Nor had any significant change occurred to graft function.

CONCLUSIONS

Paricalcitol is an effective therapy for secondary hyperparathyroidism in kidney transplant recipients.

Long-Term Therapy Outcomes When Treating Chronic Kidney Disease Patients with Paricalcitol in German and Austrian Clinical Practice (TOP Study)

Paricalcitol is approved for prevention and therapy of secondary hyperparathyroidism (sHPT) in patients with chronic kidney disease (CKD), with only short-term data in clinical routine settings. A 12-month observational study was conducted in Germany and Austria (90 centers, 761 patients) from 2008 to 2013. Laboratory values, demographical, and clinical data were documented in 629 dialysis patients and 119 predialysis patients. In predialysis patients, median intact parathormone (iPTH) was 180.0 pg/mL (n = 105) at the start of the study, 115.7 pg/mL (n = 105) at last documentation, and 151.8 pg/mL (n = 50) at month 12, with 32.4% of the last documented iPTH values in the KDOQI (Kidney Disease Outcomes Quality Initiative) target range. In dialysis patients, median iPTH was 425.5 pg/mL (n = 569) at study start, 262.3 pg/mL (n = 569) at last documentation, and 266.1 pg/mL (n = 318) at month 12, with 36.5% of dialysis patients in the KDOQI target range. Intravenous paricalcitol showed more homogenous iPTH control than oral treatment. Combined analysis of all dialysis patients indicated comparable and stable mean serum calcium and phosphate levels throughout the study. Clinical symptoms, such as itching, bone pain, and fatigue, were improved compared with study entry. The spectrum and frequency of adverse events mirrored the known pattern for patients on dialysis. Paricalcitol is efficacious and has a consistent safety profile in sHPT over 12 months.

Hemodialysis patients' preferences for the management of secondary hyperparathyroidism

BACKGROUND

Patient engagement and patient-centered care are critical in optimally managing patients with end-stage renal disease (ESRD). Understanding patient preferences is a key element of patient-centered care and shared decision making. The objective of this study was to elicit patients' preferences for the treatment of secondary hyperparathyroidism (SHPT) associated with ESRD using a discrete-choice experiment survey.

METHODS

Clinical literature, nephrologist input, patient-education resources, and a patient focus group informed development of the survey instrument, which was qualitatively pretested before its administration to a broader sample of patients. The National Kidney Foundation invited individuals in the United States with ESRD who were undergoing hemodialysis to participate in the survey. Respondents chose among three hypothetical SHPT treatment alternatives (two medical alternatives and surgery) in each of a series of questions, which were defined by attributes of efficacy (effect on laboratory values and symptoms), safety, tolerability, mode of administration, and cost. The survey instrument included a best-worst scaling exercise to quantify the relative bother of the individual attributes of surgery. Random-parameters logit models were used to evaluate the conditional relative importance of the attributes.

RESULTS

A total of 200 patients with ESRD completed the survey. The treatment attributes that were most important to the respondents were whether a treatment was a medication or surgery and out-of-pocket cost. Patients had statistically significant preferences for efficacy attributes related to symptom management and laboratory values, but placed less importance on the attributes related to mode of administration and side effects. The most bothersome attribute of surgery was the risk of surgical mortality.

CONCLUSIONS

Patients with ESRD and SHPT who are undergoing hemodialysis understand SHPT and have clear and measurable treatment preferences. These results may help inform clinicians about patients' preferences regarding treatment options for a common complication of ESRD.

LONG-TERM BONE HEALTH AFTER ROUX-EN-Y GASTRIC BYPASS: A PILOT STUDY

OBJECTIVE

This cross-sectional study was undertaken to assess metabolic bone disease by examining bone mineral density (BMD), fracture prevalence, and nutritional factors pertinent to bone in a cohort >9 years post-Rouxen-Y gastric bypass (RYGB).

METHODS

Fifty-one subjects 9.4 to 36.0 years (mean 17.0 ± 8.1) post-RYGB provided a focused history. Dietary calcium and protein were assessed. Dual-energy X-ray absorptiometry (DXA) BMD at the spine, hip, and radius and routine serum chemistries, magnesium, phosphorus, parathyroid hormone, vitamin D, vitamin K, and micronutrients were analyzed. Sixteen subjects provided 24-hour urine for measurement of calcium.

RESULTS

The mean maximum weight loss was 70.3 ± 20 kg (47.4 ± 8.9%), and mean net weight loss was 46.9 ± 23.1 kg (31.2 ± 12.5%). The prevalence rates of fracture, secondary hyperparathyroidism, and vitamin D deficiency were 15.7%, 37%, and 39%, respectively. BMD was in the osteoporotic range in 27.5%. The mean calcium:creatinine clearance ratio was 0.0124 ± 0.0131. Median intakes of dietary calcium, total calcium, protein, and vitamin D were 582.5 mg, 947.5 mg, 50.2 g, and 1,000 IU, respectively. Mean Z-scores at all sites were <0 (P<.01). A negative correlation (P<.05) was noted between distal radius Z-score and net change in BMI. Net change in BMI was greater for those with osteoporosis than those without. (P<.05) Conclusion: Many years after RYGB, BMD remains lower than expected compared to an age-, sex-, race-, and weight-matched reference population and is correlated with the amount of weight lost. Deficiencies of Vitamin D and calcium are prevalent.

ABBREVIATIONS

BMD = bone mineral density BMI = body mass index Ca:Cr = calcium:creatinine DXA = dual-energy X-ray absorptiometry PTH = parathyroid hormone RYGB = Roux-en-Y gastric bypass UD = ultradistal WHO = World Health Organization.

Changes in bone metabolic parameters following oral calcium supplementation in an adult patient with vitamin D-dependent rickets type 2A

Vitamin D-dependent rickets type 2A (VDDR2A) is a rare inherited disorder with decreased tissue responsiveness to 1,25-dihydroxyvitamin D [1,25(OH)₂D], caused by loss of function mutations in the vitamin D receptor (VDR) gene. Approximately 50 types of mutations have been identified so far that change amino acids in either the N-terminal DNA binding domain (DBD) or the C-terminal ligand binding domain (LBD) of the VDR protein. The degree of responsiveness to 1,25(OH)₂D varies between patients with VDDR2A, which may depend on their residual VDR function. In this report, we describe a female patient with VDDR2A caused by an early stop codon (R30X) in the VDR gene that resulted in a severely truncated VDR protein. She developed alopecia and bowed legs within a year after birth and was diagnosed with rickets at the age of 2. She had been treated with active vitamin D and oral calcium supplementation until 22 years of age, when she developed secondary hyperparathyroidism and high bone turnover. The genetic diagnosis of VDDR2A promoted the discontinuation of active vitamin D treatment in favor of monotherapy with oral calcium supplementation. We observed amelioration of the secondary hyperparathyroidism and normalization of bone metabolic parameters within 6 years.

Tradeoff-in-the-Nephron: A Theory to Explain the Primacy of Phosphate in the Pathogenesis of Secondary Hyperparathyroidism

Chronic kidney disease (CKD) causes secondary hyperparathyroidism (SHPT). The cardinal features of SHPT are persistence of normocalcemia as CKD progresses and dependence of the parathyroid hormone concentration ([PTH]) on phosphate influx (IP). The tradeoff-in-the-nephron hypothesis integrates these features. It states that as the glomerular filtration rate (GFR) falls, the phosphate concentration ([P]CDN) rises in the cortical distal nephron, the calcium concentration ([Ca]CDN) in that segment falls, and [PTH] rises to maintain normal calcium reabsorption per volume of filtrate (TRCa/GFR). In a clinical study, we set GFR equal to creatinine clearance (Ccr) and IP equal to the urinary excretion rate of phosphorus (EP). We employed EP/Ccr as a surrogate for [P]CDN. We showed that TRCa/Ccr was high in patients with primary hyperparathyroidism (PHPT) and normal in those with SHPT despite comparably increased [PTH] in each group. In subjects with SHPT, we examined regressions of [PTH] on EP/Ccr before and after treatment with sevelamer carbonate or a placebo. All regressions were significant, and ∆[PTH] correlated with ∆EP/Ccr in each treatment cohort. We concluded that [P]CDN determines [PTH] in CKD. This inference explains the cardinal features of SHPT, much of the evidence on which other pathogenic theories are based, and many ancillary observations.

Hypertension is a characteristic complication of X-linked hypophosphatemia

X-linked hypophosphatemia (XLH) is a group of rare disorders caused by defective proximal tubular reabsorption of phosphate. Mutations in the PHEX gene are responsible for the majority of cases. There are very few reports of long-term complications of XLH other than skeletal and dental diseases. The aim of this study was to identify the phenotypic presentation of XLH during adulthood including complications other than skeletal and dental diseases. The clinical and biochemical phenotype of 22 adult patients with a PHEX gene mutation were examined retrospectively from their medical records. 6 patients had hypertension. The average age of hypertension onset was 29.0 years. Secondary hyperparathyroidism preceded the development of hypertension in 5 patients. 1 patient developed tertiary hyperparathyroidism. 15 patients had nephrocalcinosis. 2 patients had chronic renal dysfunction. Patients with hypertension had a significantly lower eGFR (p=0.010) compared to patients without hypertension. No significant difference was found in any other parameters. To examine the genotype-phenotype correlation, 10 adult males were chosen for analysis. No significant genotype-phenotype correlation analysis was revealed in any of the complications. However, there was a possibility that the age at nephrocalcinosis onset was younger in the non-missense mutation group than in the missense mutation group (p=0.063). This study corroborated the view that early-onset hypertension could be one of the characteristic complications seen in XLH patients. Considering the limited number of our patients, further study is necessary to address a potential cause of hypertension. XLH patients require careful lifelong treatment.

Vitamin D in Chronic Kidney Disease and Dialysis Patients

Vitamin D deficiency (<20 ng/mL) and insufficiency (20–29 ng/mL) are common among patients with chronic kidney disease (CKD) or undergoing dialysis. In addition to nutritional and sunlight exposure deficits, factors that affect vitamin D deficiency include race, sex, age, obesity and impaired vitamin D synthesis and metabolism. Serum 1,25(OH)₂D levels also decrease progressively because of 25(OH)D deficiency, together with impaired availability of 25(OH)D by renal proximal tubular cells, high fibroblast growth factor (FGF)-23 and decreased functional renal tissue. As in the general population, this condition is associated with increased morbidity and poor outcomes. Together with the progressive decline of serum calcitriol, vitamin D deficiency leads to secondary hyperparathyroidism (SHPT) and its complications, tertiary hyperparathyroidism and hypercalcemia, which require surgical parathyroidectomy or calcimimetics. Kidney Disease Outcomes Quality Initiative (KDOQI) and Kidney Disease Improving Global Outcomes (KDIGO) experts have recognized that vitamin D insufficiency and deficiency should be avoided in CKD and dialysis patients by using supplementation to prevent SHPT. Many vitamin D supplementation regimens using either ergocalciferol or cholecalciferol daily, weekly or monthly have been reported. The benefit of native vitamin D supplementation remains debatable because observational studies suggest that vitamin D receptor activator (VDRA) use is associated with better outcomes and it is more efficient for decreasing the serum parathormone (PTH) levels. Vitamin D has pleiotropic effects on the immune, cardiovascular and neurological systems and on antineoplastic activity. Extra-renal organs possess the enzymatic capacity to convert 25(OH)D to 1,25(OH)₂D. Despite many unanswered questions, much data support vitamin D use in renal patients. This article emphasizes the role of native vitamin D replacement during all-phases of CKD together with VDRA when SHPT persists.

Oral Radiographic Evidence of Secondary Hyperparathyroidism in an End-Stage Renal Failure Patient: A Case Report

BACKGROUND

The authors report a case of a 42-year-old woman with End Stage Renal Disease (ESRD) undergoing dialysis therapy with the relative loss of tooth root lamina dura and several mandibular radiolucencies. Secondary hyperparathyroidism related to End Stage Renal Disease may result in the loss of bone density and radiolucent lesions, which has been previously described as Brown tumor. Findings significant for hyperparathyroidism may befound on routine dental imaging.

RESULTS

The patient was evaluated, and treatment was initiated for her dental conditions. She is at present still on the kidney transplant waiting list.

CONCLUSION

Patients with End Stage Renal Disease and hyperparathyroidism require communication and cooperation between dentists and physicians.

PRACTICAL IMPLICATIONS

It is important for dentists to consider Brown tumor as a possible diagnosis of radiolucent jaw lesions.

Surgical treatment of secondary hyperparathyroidism in elderly patients: an institutional experience

BACKGROUND

Secondary hyperparathyroidism in elderly fragile patients presents clinical difficulties due to severity of symptoms and related comorbidity. The optimal surgical approach for this group of patients is still debated.

AIM

The aim of the study was to define the optimal technique of parathyroidectomy in elderly patients with secondary hyperparathyroidism.

METHODS

Retrospective analysis in a series of 253 patients including 35 elderly individuals at a single institution was carried out. Postoperative parathyroid hormone decrease, surgical complications and symptoms control were analyzed for all patients in relation to the types of parathyroidectomy performed.

RESULTS

In elderly patients, total parathyroidectomy was the most used approach. Subtotal parathyroidectomy was mostly reserved for younger patients suitable for kidney transplantation. No elderly patients treated with total parathyroidectomy were autotransplanted. No significant difference in surgical complications was observed between younger and elderly patients and considering the different procedures. Adequate symptom control after surgery was achieved in almost 90% of patients. A limited rate of recurrence requiring repeat surgery was observed only after subtotal parathyroidectomy.

DISCUSSION

Considering the features of all types of parathyroidectomy, very low recurrence rate, contained postoperative hypocalcemia and limited complications following total parathyroidectomy, might represent specific advantages for elderly patients.

CONCLUSIONS

Total parathyroidectomy without parathyroid transplantation is safe for elderly patients with secondary hyperparathyroidism and a good alternative to the well-established total parathyroidectomy with autografting.

Effect of Etelcalcetide vs Placebo on Serum Parathyroid Hormone in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism: Two Randomized Clinical Trials

IMPORTANCE

Secondary hyperparathyroidism contributes to extraskeletal complications in chronic kidney disease.

OBJECTIVE

To evaluate the effect of the intravenous calcimimetic etelcalcetide on serum parathyroid hormone (PTH) concentrations in patients receiving hemodialysis.

DESIGN, SETTING, AND PARTICIPANTS

Two parallel, phase 3, randomized, placebo-controlled treatment trials were conducted in 1023 patients receiving hemodialysis with moderate to severe secondary hyperparathyroidism. Trial A was conducted in 508 patients at 111 sites in the United States, Canada, Europe, Israel, Russia, and Australia from March 12, 2013, to June 12, 2014; trial B was conducted in 515 patients at 97 sites in the same countries from March 12, 2013, to May 12, 2014.

INTERVENTIONS

Intravenous administration of etelcalcetide (n = 503) or placebo (n = 513) after each hemodialysis session for 26 weeks.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was the proportion of patients achieving greater than 30% reduction from baseline in mean PTH during weeks 20-27. A secondary efficacy end point was the proportion of patients achieving mean PTH of 300 pg/mL or lower.

RESULTS

The mean age of the 1023 patients was 58.2 (SD, 14.4) years and 60.4% were men. Mean PTH concentrations at baseline and during weeks 20-27 were 849 and 384 pg/mL vs 820 and 897 pg/mL in the etelcalcetide and placebo groups, respectively, in trial A; corresponding values were 845 and 363 pg/mL vs 852 and 960 pg/mL in trial B. Patients randomized to etelcalcetide were significantly more likely to achieve the primary efficacy end point: in trial A, 188 of 254 (74.0%) vs 21 of 254 (8.3%; P < .001), for a difference in proportions of 65.7% (95% CI, 59.4%-72.1%) and in trial B, 192 of 255 (75.3%) vs 25 of 260 (9.6%; P < .001), for a difference in proportions of 65.7% (95% CI, 59.3%-72.1%). Patients randomized to etelcalcetide were significantly more likely to achieve a PTH level of 300 pg/mL or lower: in trial A, 126 of 254 (49.6%) vs 13 of 254 (5.1%; P < .001), for a difference in proportions of 44.5% (95% CI, 37.8%-51.2%) and in trial B, 136 of 255 (53.3%) vs 12 of 260 (4.6%; P < .001), for a difference in proportions of 48.7% (95% CI, 42.1%-55.4%). In trials A and B, respectively, patients receiving etelcalcetide had more muscle spasms (12.0% and 11.1% vs 7.1% and 6.2% with placebo), nausea (12.4% and 9.1% vs 5.1% and 7.3%), and vomiting (10.4% and 7.5% vs 7.1% and 3.1%).

CONCLUSIONS AND RELEVANCE

Among patients receiving hemodialysis with moderate to severe secondary hyperparathyroidism, use of etelcalcetide compared with placebo resulted in greater reduction in serum PTH over 26 weeks. Further studies are needed to assess clinical outcomes as well as longer-term efficacy and safety.

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: NCT01788046.

Effect of Etelcalcetide vs Cinacalcet on Serum Parathyroid Hormone in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism: A Randomized Clinical Trial

IMPORTANCE

Secondary hyperparathyroidism contributes to extraskeletal calcification and is associated with all-cause and cardiovascular mortality. Control is suboptimal in the majority of patients receiving hemodialysis. An intravenously (IV) administered calcimimetic could improve adherence and reduce adverse gastrointestinal effects.

OBJECTIVE

To evaluate the relative efficacy and safety of the IV calcimimetic etelcalcetide and the oral calcimimetic cinacalcet.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, double-dummy active clinical trial was conducted comparing IV etelcalcetide vs oral placebo and oral cinacalcet vs IV placebo in 683 patients receiving hemodialysis with serum parathyroid hormone (PTH) concentrations higher than 500 pg/mL on active therapy at 164 sites in the United States, Canada, Europe, Russia, and New Zealand. Patients were enrolled from August 2013 to May 2014, with end of follow-up in January 2015.

INTERVENTIONS

Etelcalcetide intravenously and oral placebo (n = 340) or oral cinacalcet and IV placebo (n = 343) for 26 weeks. The IV study drug was administered 3 times weekly with hemodialysis; the oral study drug was administered daily.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was noninferiority of etelcalcetide at achieving more than a 30% reduction from baseline in mean predialysis PTH concentrations during weeks 20-27 (noninferiority margin, 12.0%). Secondary end points included superiority in achieving biochemical end points (>50% and >30% reduction in PTH) and self-reported nausea or vomiting.

RESULTS

The mean (SD) age of the trial participants was 54.7 (14.1) years and 56.2% were men. Etelcalcetide was noninferior to cinacalcet on the primary end point. The estimated difference in proportions of patients achieving reduction in PTH concentrations of more than 30% between the 198 of 343 patients (57.7%) randomized to receive cinacalcet and the 232 of 340 patients (68.2%) randomized to receive etelcalcetide was -10.5% (95% CI, -17.5% to -3.5%, P for noninferiority, <.001; P for superiority, .004). One hundred seventy-eight patients (52.4%) randomized to etelcalcetide achieved more than 50% reduction in PTH concentrations compared with 138 patients (40.2%) randomized to cinacalcet (P = .001; difference in proportions, 12.2%; 95% CI, 4.7% to 19.5%). The most common adverse effect was decreased blood calcium (68.9% vs 59.8%).

CONCLUSIONS AND RELEVANCE

Among patients receiving hemodialysis with moderate to severe secondary hyperparathyroidism, the use of etelcalcetide was not inferior to cinacalcet in reducing serum PTH concentrations over 26 weeks; it also met superiority criteria. Further studies are needed to assess clinical outcomes as well as longer-term efficacy and safety.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT1896232.