Parathyroidectomy versus oral cinacalcet on cardiovascular parameters in peritoneal dialysis patients with advanced secondary hyperparathyroidism (PROCEED): a randomized trial.

BACKGROUND: This trial aimed to evaluate oral cinacalcet versus total parathyroidectomy (PTx) with forearm autografting on cardiovascular surrogate outcomes and health-related quality of life (HRQOL) measures in dialysis patients with advanced secondary hyperparathyroidism (SHPT). DESIGN: In this pilot prospective randomized trial conducted in two university-affiliated hospitals, 65 adult peritoneal dialysis patients with advanced SHPT were randomized to receive either oral cinacalcet or PTx. Primary endpoints were changes in left ventricular (LV) mass index by cardiac magnetic resonance imaging and coronary artery calcium scores (CACS) over 12 months. Secondary endpoints included changes in heart valves calcium scores, aortic stiffness, biochemical parameters of chronic kidney disease-mineral bone disease (CKD-MBD) and HRQOL measures over 12 months. RESULTS: Changes in LV mass index, CACS, heart valves calcium score, aortic pulse wave velocity and HRQOL did not differ between groups or within groups, despite significant reductions in plasma calcium, phosphorus and intact parathyroid hormone in both groups. Cinacalcet-treated patients experienced more cardiovascular-related hospitalizations than those who underwent PTx (P = .008) but the difference became insignificant after adjusting for baseline difference in heart failure (P = .43). With the same monitoring frequency, cinacalcet-treated patients had fewer hospitalizations due to hypercalcemia (1.8%) than patients who underwent PTx (16.7%) (P = .005). No significant changes were observed in HRQOL measures in either group. CONCLUSIONS: Both cinacalcet and PTx effectively improved various biochemical abnormalities of CKD-MBD and stabilized but did not reduce LV mass, coronary artery and heart valves calcification, or arterial stiffness, or improve patient-centered HRQOL measures in PD patients with advanced SHPT. Cinacalcet may be used in place of PTx for treating advanced SHPT. Long-term and powered studies are required to evaluate PTx versus cinacalcet on hard cardiovascular outcomes in dialysis patients. Trial registration: ClinicalTrials.gov identifier: NCT01447368.

Management of Primary Hyperparathyroidism With Severe Hypercalcemia During the COVID-19 Pandemic.

PURPOSE: In patients with primary hyperparathyroidism (PHPT) and severe hypercalcemia, parathyroidectomy remains the only curative therapy. During the coronavirus disease 2019 (COVID-19) pandemic, when many hospital visits are suspended and surgeries cannot be performed, the management of these patients represents a challenging clinical situation. This article presents a literature review and discussion of the pharmacologic management of PHPT and severe hypercalcemia, which can be used as a temporary measure during the COVID-19 pandemic until parathyroidectomy can be performed safely. METHODS: This narrative review was conducted by searching literature on the PubMed, Medline, and Google Scholar databases using the terms primary hyperparathyroidism, hypercalcemia, cinacalcet, bisphosphonates, denosumab, vitamin D, raloxifene, hormone replacement therapy, coronavirus, and COVID-19. FINDINGS: Appropriate monitoring and remote medical follow-up of these patients are essential until the resolution of the pandemic. Cinacalcet is the drug of choice for controlling hypercalcemia, whereas bisphosphonate or denosumab is the drug for improving bone mineral density. Combined therapy with cinacalcet and bisphosphonates or cinacalcet and denosumab should be considered when the effects on serum calcium and bone mineral density are simultaneously desired. IMPLICATIONS: Medical management of PHPT and severe hypercalcemia presents a reasonable alternative for parathyroid surgery during the COVID-19 outbreak and should be instituted until the pandemic ends and surgery can be performed safely.

Surgical outcomes of parathyroidectomy for secondary hyperparathyroidism resistant to calcimimetic treatment: A retrospective single-center cohort study.

To evaluate the surgical outcomes of parathyroidectomy (PTx) for secondary hyperparathyroidism (SHPT) resistant to calcimimetic treatment, we retrospectively studied 187 patients with SHPT who had no history of calcimimetic treatment (NCMT) (NCMT group) and 186 patients with SHPT who were resistant to calcimimetic treatment (RCMT) (RCMT group). Success rate and operative time of PTx were compared among the two groups. Operative time was significantly longer in the RCMT group than in the NCMT group (180 vs 158 minutes, P < .001), but the difference was attenuated after multivariate adjustment including the weight of the largest parathyroid gland. No significant differences were observed in success rate of PTx (90.9% vs 91.4%, P = 1.000) between the two groups. In patients with SHPT who are resistant to calcimimetic treatment, operative time could be elongated but success rate of PTx remains unchanged.

Therapeutic Effect of Calcimimetics on Osteoclast-Osteoblast Crosslink in Chronic Kidney Disease and Mineral Bone Disease.

We have previously demonstrated calcimimetics optimize the balance between osteoclastic bone resorption and osteoblastic mineralization through upregulating Wingless and int-1 (Wnt) signaling pathways in the mouse and cell model. Nonetheless, definitive human data are unavailable concerning therapeutic effects of Cinacalcet on chronic kidney disease and mineral bone disease (CKD-MBD) and osteoclast-osteoblast interaction. We aim to investigate whether Cinacalcet therapy improves bone mineral density (BMD) through optimizing osteocytic homeostasis in a human model. Hemodialysis patients with persistently high intact parathyroid hormone (iPTH) levels > 300 pg/mL for more than 3 months were included and received fixed dose Cinacalcet (25 mg/day, orally) for 6 months. Bone markers presenting osteoclast-osteoblast communication were evaluated at baseline, the 3rd and the 6th month. Eighty percent of study patients were responding to Cinacalcet treatment, capable of improving BMD, T score and Z score (16.4%, 20.7% and 11.1%, respectively). A significant correlation between BMD improvement and iPTH changes was noted (r = -0.26, p < 0.01). Nonetheless, baseline lower iPTH level was associated with better responsiveness to Cinacalcet therapy. Sclerostin, an inhibitor of canonical Wnt/ß-catenin signaling, was decreased from 127.3 ± 102.3 pg/mL to 57.9 ± 33.6 pg/mL. Furthermore, Wnt-10b/Wnt 16 expressions were increased from 12.4 ± 24.2/166.6 ± 73.3 pg/mL to 33.8 ± 2.1/217.3 ± 62.6 pg/mL. Notably, procollagen type I amino-terminal propeptide (PINP), a marker of bone formation and osteoblastic activity, was increased from baseline 0.9 ± 0.4 pg/mL to 91.4 ± 42.3 pg/mL. In contrast, tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), a marker of osteoclast activity, was decreased from baseline 16.5 ± 0.4 mIU/mL to 7.7 ± 2.2 mIU/mL. Moreover, C-reactive protein levels were suppressed from 2.5 ± 0.6 to 0.8 ± 0.5 mg/L, suggesting the systemic inflammatory burden may be benefited after optimizing the parathyroid-bone axis. In conclusion, beyond iPTH suppression, our human model suggests Cinacalcet intensifies BMD through inhibiting sclerostin expression and upregulating Wnt-10b/Wnt 16 signaling that activates osteoblastic bone formation and inhibits osteoclastic bone resorption and inflammation. From the perspective of translation to humans, this research trial brings a meaningful insight into the osteoblast-osteoclast homeostasis in Cinacalcet therapy for CKD-MBD.

Cinacalcet as a First-Line Treatment in Neonatal Severe Hyperparathyroidism Secondary to Calcium Sensing Receptor (CaSR) Mutation.

INTRODUCTION: Neonatal severe hyperparathyroidism (NSHPT) is a rare cause of neonatal hypercalcemia caused by a loss of function mutation in the calcium-sensing receptor (CaSR). Hypercalcemia in NSHPT can be life-threatening. Maintenance of serum calcium within a safe range is the primary goal of treatment through hydration, forced diuresis, and bisphosphonate treatment, nevertheless most cases require parathyroidectomy. We report a case with NSHPT diagnosed on the first day of life (DoL) and successfully treated with cinacalcet as the first-line treatment from the 2nd DoL up to the age of 18 months. CASE REPORT: A full-term baby evaluated for weight loss at postnatal 14th hour and found to have hypercalcemia (14.4 mg/dL, reference range [RR]: 8.0-11.3). Despite hydration and diuresis, hypercalcemia persisted. Further evaluation revealed a parathyroid hormone (PTH) level of 1,493 pg/mL (RR: 15-65) and urine Ca/Cr of 0.09 mg/mg (RR: 0.03-0.81). Cinacalcet treatment was initiated on the 2nd DoL with the diagnosis of NSHPT due to hypocalciuric hypercalcemia and elevated PTH level. Ca levels decreased to normal levels on the 7th DoL. She was discharged from hospital at postnatal day 15 on cinacalcet treatment and still continued at 18 months of age. Sequencing of CaSR revealed a novel homozygous c.1836G>A (p.G613E) mutation in the patient, for which the parents and sister were heterozygous. CONCLUSION: This case represents the youngest age at cinacalcet initiation and the longest duration without parathyroidectomy in a homozygous NSHPT and demonstrates that cinacalcet is an effective first-line treatment in patients who are responsive to this treatment modality and allows avoiding/delay in surgical intervention in NSHPT.

Real World Use and Effects of Calcimimetics in Treating Mineral and Bone Disorder in Hemodialysis Patients.

BACKGROUND: Calcimimetics are used to treat mineral and bone disorder by reducing parathyroid hormone (PTH), calcium (Ca), and phosphorus (Phos). The study objectives were to assess the control of PTH, Ca, and Phos over time in patients receiving cinacalcet or etelcalcetide as well as dosing and time to discontinuation for etelcalcetide. METHODS: This was a retrospective cohort study using electronic medical records from small and independent dialysis centers. Adults ≥18 years of age were identified as cinacalcet or etelcalcetide users based on the first calcimimetic received in 2018 (index date). Patients were followed from the index date until parathyroidectomy, kidney transplant, death, or end of data (December 31, 2018). Analyses of mean PTH, Ca, and Phos, as well as target achievement of PTH, Ca, and Phos were conducted over a 9-month period. Discontinuation with etelcalcetide was measured with the Kaplan-Meier estimator. RESULTS: There were 1,346 cinacalcet patients (mean age 60.5 years, 43.5% female, and 47.1% Black) and 1,255 etelcalcetide patients (mean age 63.4 years, 46.6% female, and 38.5% Black). At baseline, the proportions in target were similar for etelcalcetide versus cinacalcet: 36 versus 38% for PTH, 79 versus 80% for Ca, and 43 versus 44% for Phos. Overall, 40-47% of cinacalcet users and 48-62% of etelcalcetide users were observed to be in target for PTH over 9 months. The proportion in target for Phos ranged from 41 to 46% for cinacalcet and 46-51% for etelcalcetide. The proportion in target for Ca ranged from 74 to 78% for cinacalcet and 60-73% for etelcalcetide. Etelcalcetide 12-month discontinuation was 37.4%. CONCLUSION: Both calcimimetics were effective in keeping PTH, Ca, and Phos levels within target. Patients receiving etelcalcetide tended to have lower laboratory values for PTH, Ca, and Phos over time, while patients receiving cinacalcet tended to be more likely to be in target for Ca over time.

[Cholecalciferol supplementation improves secondary hyperparathyroidism control in hemodialysis patients].

Introduction: Vitamin D deficiency is common among hemodialysis (HD) patients and is an important component in the pathogenesis of secondary hyperparathyroidism (SHPT). We herein report our experience on the impact of cholecalciferol supplementation on PTH levels in a group of HD patients. Patients and methods: We selected 122 HD patients. The main selection criteria were 25- hydroxyvitamin D (25(OH)D) levels ≤30 ng/mL and SHPT defined as PTH levels >300 pg/mL or PTH levels between 150-300 pg/mL during therapy with cinacalcet or paricalcitol. 82 patients agreed to receive cholecalciferol at the fixed dose of 25,000 IU per week orally for 12 months, while the remaining 40 represented the control group. The main endopoints of the study were the reduction in PTH levels ≥30% compared to baseline values and the increase of 25(OH)D levels to values >30 ng/mL. Results: At follow-up PTH levels decreased in the supplemented group from 476 ±293 to 296 ± 207 pg/mL (p<0.001), 25(OH)D levels increased from 10.3 ± 5.7 to 33.5 ± 11.2 ng/mL (p<0.001), serum calcium increased from 8.6 ± 0.5 to 8.8 ± 0.6 mg/dL (p<0.05) while serum phosphorus did not change. In this group the mean doses of paricalcitol were significantly reduced, from 8.7 ± 4.0 to 6.1 ± 3.9 µg/week (p<0.001). Moreover, in this group there were a significant increase of hemoglobin levels, from 11.6 ± 1.3 to 12.2 ± 1.1 g/dL (p <0.01) and a significant reduction of erythropoietin doses (p<0.05). In the control group the 25(OH)D and PTH levels did not change, while cinacalcet doses increased from 21 ±14 to 43 ± 17 mg/d (p<0.01). Conclusions: Vitamin deficiency is very common in HD patients. Cholecalciferol treatment significantly increased serum 25(OH)D levels, significantly decreased PTH levels and paricalcitol doses, concurrently entailing a better control of anemia.

Cinacalcet use in pediatric chronic kidney disease. A survey study.

OBJECTIVES: To evaluate the practice and attitude of pediatrics nephrologists about cinacalcet use in children. METHODS: An electronic structured questionnaire was answered by pediatric nephrologists practicing in the Kingdom of Saudi Arabia (KSA) and Gulf Council countries (GCC). RESULTS: A total of 42  pediatric nephrologists responded, of them, 42% used cinacalcet for young children ≤5 years of age and 79% used for children. There were wide variations in the method of administration (examples: crushed, divided, whole tablets), monitoring, doses and response definition, and follow-up. No serious complications after starting cinacalcet was observed in 50%, while 40% reported various complications, mainly hypocalcemia (70%). Cinacalcet was stopped without achieving the target parathyroid hormone in more than half (55%) of children because of intractable adverse effects (40%), poor response (30%), non-adherence (25%), or high cost (5%). CONCLUSION: Cinacalcet is used by the majority of pediatric nephrologists in KSA and GCC. A standard clinical guideline is needed to be followed by all users.

Cinacalcet studies in pediatric subjects with secondary hyperparathyroidism receiving dialysis.

BACKGROUND: Secondary hyperparathyroidism (sHPT), a complication of chronic kidney disease (CKD) characterized by persistently elevated parathyroid hormone (PTH), alterations in calcium-phosphorus homeostasis, and vitamin D metabolism, affects 50% of children receiving dialysis. A significant proportion of these children develop CKD-mineral and bone disorder (CKD-MBD), associated with an increased risk of fractures and vascular calcification. The standard of care for sHPT in children includes vitamin D sterols, calcium supplementation, and phosphate binders. Several agents are approved for sHPT treatment in adults undergoing dialysis, including vitamin D analogs and calcimimetics, with limited information on their safety and efficacy in children. The calcimimetic cinacalcet is approved for use in adults with sHPT on dialysis, but is not approved for pediatric use outside Europe. METHODS: This review provides dosing, safety, and efficacy information from Amgen-sponsored cinacalcet pediatric trials and data from non-Amgen sponsored clinical studies. RESULTS: The Amgen cinacalcet pediatric clinical development program consisted of two Phase 3 randomized studies, one Phase 3 single arm extension study, one open-label Phase 2 study, and two open-label Phase 1 studies. Effects of cinacalcet on PTH varied across studies. Overall, 7.4 to 57.1% of subjects who received cinacalcet in an Amgen clinical trial attained PTH levels within recommended target ranges and 22.2 to 70.6% observed a ≥ 30% reduction in PTH. In addition, significant reductions in PTH were demonstrated in all non-Amgen-supported studies. CONCLUSIONS: To help inform the pediatric nephrology community, this manuscript contains the most comprehensive review of cinacalcet usage in pediatric CKD patients to date.

The use of cinacalcet after pediatric renal transplantation: an international CERTAIN Registry analysis.

BACKGROUND: Secondary hyperparathyroidism (SHPT) may persist after renal transplantation (RTx), inducing hypophosphatemia and hypercalcemia that precludes the use of vitamin D analogs. The calcimimetic cinacalcet improved plasma calcium and parathyroid hormone (PTH) levels in randomized controlled trials in adults after RTx, but pediatric data are scarce. METHODS: In this retrospective study, we analyzed 20 pediatric patients from the Cooperative European Paediatric Renal TransplAnt Initiative (CERTAIN) Registry who received cinacalcet after RTx. The results are presented as median and interquartile range (25th-75th percentile). RESULTS: At 13.7 (11.0-16.5) years of age, 20 pediatric patients received a renal allograft. Cinacalcet was introduced at 0.4 (0.3-2.7) years post-transplant at an estimated glomerular filtration rate (eGFR) of 50 (34-66) mL/min/1.73 m2, plasma calcium of 2.58 (2.39-2.71) mmol/L, age-standardized (z score) phosphate of - 1.7 (- 2.7-- 0.4), and PTH of 136 (95-236) ng/L. The starting dose of cinacalcet was 0.5 (0.3-0.8) mg/kg per day, with a maximum dose of 1.1 (0.5-1.3) mg/kg per day. With a follow-up of 3.0 (1.5-3.6) years on cinacalcet therapy, eGFR remained stable; PTH levels decreased to 66 (56-124) ng/L at the last follow-up (p = 0.015). One patient displayed hypocalcemia (1.8 mmol/L). Cinacalcet was withdrawn in three patients (hypocalcemia, parathyroidectomy, incompliance). Nephrocalcinosis of the graft was not reported. CONCLUSIONS: This pilot study suggests that cinacalcet as off-label therapy for SHPT after pediatric RTx is efficacious in controlling post-transplant SHPT with acceptable tolerability. Continuing cinacalcet even with normal PTH can lead to dangerous life-threatening hypocalcemia. Therefore, at each subsequent visit, the need to continue cinacalcet must be assessed.

Safety and Efficacy of a 3-Year Therapy With Cinacalcet in Persistent Hyperparathyroidism After Renal Transplant.

BACKGROUND: Persistent post-transplant hyperparathyroidism (PPTHP) can occur in 20% to 50% of renal transplant recipients. The aim of this study was to analyze safety and efficacy of long-term cinacalcet therapy in a group of renal transplant recipients with PPTHP. METHODS: A single center retrospective cohort study including renal transplant recipients, adults (>18 years old) with PPTHP and hypercalcemia. Inclusion criteria for cinacalcet therapy was increased parathormone levels (PTH > 65 pg/mL) associated with serum calcium >11.5 mg/dL any time after transplant or calcium >10.2 mg/dL within the first year after transplant. The follow-up period was 3 years. Demographic, laboratory data and adverse events were assessed. RESULTS: Forty-six patients were included, mean age of 50 ± 11 years old, majority of white race (60%), male (58%), with a pretransplant length on dialysis of 67 ± 34 months. Cinacalcet therapy was started 37 ± 40 months after transplant, and normal calcium levels were achieved after 6 months of therapy. PTH levels presented a steady reduction over time, reaching levels near normal after 36 months (317 ± 242 vs 145 ± 72 pg/mL, baseline × month 36, P < .05). Renal function remained stable over time (GFR > 60 mL/min/1.73 m2) and no acute rejection episodes were observed. Most common adverse events were mild gastrointestinal symptoms. In 6 patients (12.5%) treatment was interrupted due to adverse events. Only 1 case (2%) was classified as treatment failure. CONCLUSION: Cinacalcet therapy proved to be efficient for PPTHP and safe for graft and patient. Long-term treatment reduced PTH levels to near normal range.

Early response of the parathyroid gland to withdrawal of a calcimimetic compound in uremic rats.

Little is known about changes in parathyroid cells when calcimimetics are withdrawn. We examined the response of parathyroid glands to cinacalcet (Cina) withdrawal in uremic Sprague-Dawley rats fed a high-phosphate diet to develop secondary hyperparathyroidism and divided into groups treated with vehicle (UC), Cina, and Cina and maxacalcitol (Maxa), a vitamin D receptor activator (CiNa + Maxa). After 2 wk of treatment, vehicle and Cina were withdrawn and Maxa was continued. Rats were analyzed immediately (day 0) and 7 days (day 7) after withdrawal. The Cina and CiNa + Maxa groups had significantly lower parathyroid hormone (PTH) than the UC group on day 0, although PTH in the Cina group reached UC levels on day 7. On day 0, there were significantly more proliferating cell nuclear antigen-positive cells in the UC group compared with normal controls, and this increase was significantly suppressed in the Cina and CiNa + Maxa groups. On day 7, the Cina group, but not the CiNa + Maxa group, showed a significant increase in proliferating cell nuclear antigen-positive cells compared with the UC group. This increase was related to parathyroid cell diameter regression to UC levels, whereas combination treatment maintained diameter suppression. These results indicate that parathyroid growth activity is stimulated by Cina withdrawal, although the PTH level was not further increased. Continuous administration of Cina may be required for optimal control of secondary hyperparathyroidism, and simultaneous use of a vitamin D receptor activator may be advisable during Cina withdrawal.

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.

Short-term medical treatment of hypercalcaemia in primary hyperparathyroidism predicts symptomatic response after parathyroidectomy.

BACKGROUND: Primary hyperparathyroidism is often associated with non-disease-specific symptoms. The aim of this study was to evaluate whether normalization of hypercalcaemia with short-term medical treatment can be used to predict the effects of parathyroidectomy and guide in surgical decision-making. METHODS: This observational study included patients who received calcimimetic treatment for 4 weeks before parathyroidectomy (30-60 mg daily). A panel of tests was used to assess various aspects of quality of life (European Organisation and Treatment of Cancer QLQ-C30 core questionnaire, Hospital Anxiety and Depression Scale and Positive State of Mind questionnaire), cognitive function (Montreal Cognitive Assessment) and muscle strength (timed-stands test). The tests were carried out at baseline, after 4 weeks of calcimimetic treatment, and at 6 weeks and 6 months after parathyroidectomy. The predictive values of changes during calcimimetic treatment were determined for each test. RESULTS: The study included 110 patients of median age 62 years (91 women). Calcimimetic treatment resulted in normalization of calcium levels and improvements in quality-of-life parameters. The time spent on the timed-stands test was significantly shortened. Eleven of 38 participants with a baseline Montreal Cognitive Assessment score below 26, indicating mild cognitive impairment, reached scores of at least 26 during treatment with calcimimetic. Improvements during treatment with calcimimetic correlated well with postoperative outcomes (positive predictive values 74-96 per cent). CONCLUSION: The method described in this study may be used to aid surgical decision-making for patients with primary hyperparathyroidism and non-disease-specific symptoms by predicting the effects of normalization of hypercalcaemia.

ANTECEDENTES: El hiperparatiroidismo primario (pHPT) a menudo se asocia con síntomas no específicos de la enfermedad. El objetivo de este estudio fue evaluar si la normalización de la hipercalcemia a corto plazo con tratamiento médico se podría usar para predecir los efectos de la paratiroidectomía y guiar la toma de decisiones quirúrgicas. MÉTODOS: Estudio observacional (ClinicalTrials.gov, registro NCT02227264) que incluyó 110 pacientes programados para paratiroidectomía (mediana de edad 62 años; 91 mujeres). Intervención: tratamiento calcimimético, cuatro semanas, 30-60 mg al día. Medidas de resultado: Un panel de pruebas para evaluar los aspectos de la calidad de vida (cuestionario de calidad de vida core 30, QLQ-C30; escala hospitalaria de ansiedad y depresión (HAD) y estado mental positivo (PSOM); función cognitiva (evaluación cognitiva de Montreal, MoCa) y fuerza muscular (Timed-Stands Test, TST). Las pruebas se realizaron cuatro veces: al inicio del estudio (basal), después de cuatro semanas de tratamiento calcimimético, a las seis semanas y seis meses después de la paratiroidectomía. Para cada prueba se determinaron los valores predictivos de los cambios durante el tratamiento calcimimético. RESULTADOS: El tratamiento con fármacos calcimiméticos determinó una normalización en los niveles de calcio y una mejoría en los parámetros de calidad de vida. El tiempo del TST se redujo significativamente. Once de los 38 participantes con una puntuación MoCa basal < 26, definida como deterioro cognitivo leve, alcanzaron puntuaciones ≥ 26 durante el uso de la medicación. Las mejoras observadas durante el tratamiento mostraron una buena correlación con el resultado postoperatorio (valores predictivos positivos 74-96%). CONCLUSIÓN: Este estudio presenta un método basado en la predicción de los efectos de la normalización de la hipercalcemia para ayudar en la toma de decisiones quirúrgicas en pacientes con pHPT y síntomas no específicos de la enfermedad.

Cinacalcet plus vitamin D versus vitamin D alone for the treatment of secondary hyperparathyroidism in patients undergoing dialysis: a meta-analysis of randomized controlled trials.

BACKGROUND: Secondary hyperparathyroidism (SHPT) is a common and serious complication of chronic kidney disease, particularly in end-stage renal disease. Currently, both cinacalcet and vitamin D are used to treat SHPT via two different mechanisms, but it is still unclear whether the combination use of these two drugs can be a safe and effective alternative to vitamin D alone. Therefore, the aim of this meta-analysis was to assess the efficacy and safety of cinacalcet plus vitamin D in the treatment of SHPT. METHODS: Four electronic databases, including PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science, were searched for eligible publications. All randomized-controlled trials comparing cinacalcet plus vitamin D with vitamin D alone in SHPT patients undergoing dialysis were included. Mean difference (MD) with 95% confidence intervals (CIs) and risk ratios (RRs) with 95% CIs were calculated using a random-effects model or fixed-effects model. Sensitivity analysis was conducted by removing any one study successively to estimate the stability of the pooled results, and subgroup analysis was carried out to explore potential sources of heterogeneity, and funnel plots were used to test publication bias. RESULTS: A total of 8 randomized-controlled trials involving 1480 patients were included in the study. Compared with vitamin D treatment, the combination use of cinacalcet and vitamin D significantly lowered serum calcium (MD - 0.82, 95% CI - 1.02 to - 0.61, P < 0.001), phosphorus (MD - 0.57, 95% CI - 0.97 to - 0.18, P = 0.005), and calcium × phosphorus product (MD - 9.41, 95% CI - 10.00 to - 8.82, P < 0.001). However, there was no difference in serum parathyroid hormone (PTH, MD 43.99, 95% CI - 49.22 to 137.20, P = 0.35), ≥ 30% reduction in PTH (RR 1.02, 95% CI 0.69-1.52, P = 0.91), and PTH achieve 150-300 pg/ml (RR 0.88, 95% CI 0.68-1.15, P = 0.35). Moreover, the combination therapy did not increase the risk of all adverse events, all-cause mortality, diarrhea, muscle spasms, and headache (all P > 0.05), but had a higher risk of hypocalcemia (RR 17.98, 95% CI 5.68-56.99, P < 0.001), and nausea or vomiting (RR 3.47, 95% CI 2.25-5.35, P < 0.001). CONCLUSIONS: In comparison with vitamin D alone, the combination use of cinacalcet and vitamin D significantly lowered serum calcium, phosphorus, and the calcium × phosphorus product, and did not increase the risk of all adverse events, all-cause mortality, diarrhea, muscle spasms, and headache, whereas had no effect on serum PTH and increased the risk of hypocalcemia and nausea or vomiting. Future studies are needed to assess the effects of cinacalcet plus vitamin D on PTH level, cardiovascular events, and other clinical outcomes in larger samples with longer durations.

Pathogenesis and management of vascular calcification in CKD and dialysis patients.

Patients with chronic kidney disease (CKD) have a predisposition to develop vascular calcification due to dysregulated homeostatic mechanisms, which lead to an imbalance in the circulatory promoters and inhibitors of vascular calcification, leading to a net calcification stress. These factors promote ectopic calcification and induce vascular smooth muscle cells to undergo osteogenic differentiation and actively calcify the vascular media. The article summarizes clinically relevant pathogenic mechanisms of vascular calcification in patients with CKD and in dialysis patients and summarizes novel therapeutic interventions. In addition to the management of traditional cardiovascular risk factors, patients with CKD-mineral and bone disorder need close attention in the management of the mineral metabolism to prevent adverse effects on the bone and vascular compartments. This article reviews current evidence and therapeutic guidelines in the management of mineral metabolism in CKD and dialysis.

Effectiveness of cinacalcet treatment for secondary hyperparathyroidism on hospitalization: Results from the MBD-5D study.

OBJECTIVES: To elucidate the effect of cinacalcet use on all-cause and cause-specific hospitalization outcomes using a prospective cohort of maintenance hemodialysis patients. METHODS: We used data from a prospective cohort of Japanese hemodialysis patients with secondary hyperparathyroidism and examined baseline characteristics as well as longitudinal changes. All patients were cinacalcet-naïve at study enrollment. Further, we used a marginal structural model to account for time-varying confounders on cinacalcet initiation and hospitalization outcomes, and an Andersen-Gill-type recurrent event model to account for any recurring events of hospitalization in the outcome analysis using the weighted dataset. RESULTS: Among the 3,276 patients, cinacalcet treatment was initiated in 1,384 patients during the entire follow-up. Cinacalcet users were slightly younger, included more patients with chronic glomerulonephritis and fewer patients with diabetes, were more likely to have a history of parathyroidectomy, and were more often used receiving vitamin D receptor activator, phosphate binders, and iron supplements. The overall hospitalization analysis yielded a hazard ratio (HR) of 0.97 (95% confidence interval [CI]: 0.80, 1.18). A trend toward a mild protective association was observed for cardiovascular-related hospitalizations (HR: 0.85; 95% CI: 0.64, 1.14). In the subgroup analysis, a protective association was seen due to cinacalcet use for infection-related hospitalizations in the lowest intact parathyroid hormone group (HR: 0.36; 95% CI: 0.14, 0.95). CONCLUSIONS: Cinacalcet initiation in patients on maintenance hemodialysis had no effect on all-cause and cause-specific hospitalizations. Although the overall association was statistically not significant, cinacalcet may have a protective association on cardiovascular-related hospitalization in all patients and infection-related hospitalization in patient with low intact parathyroid hormone.

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.

Cinacalcet corrects biased allosteric modulation of CaSR by AHH autoantibody.

Biased agonism is a paradigm that may explain the selective activation of a signaling pathway via a GPCR that activates multiple signals. The autoantibody-induced inactivation of the calcium-sensing receptor (CaSR) causes acquired hypocalciuric hypercalcemia (AHH). Here, we describe an instructive case of AHH in which severe hypercalcemia was accompanied by an increased CaSR antibody titer. These autoantibodies operated as biased allosteric modulators of CaSR by targeting its Venus flytrap domain near the Ca2+-binding site. A positive allosteric modulator of CaSR, cinacalcet, which targets its transmembrane domain, overcame this autoantibody effect and successfully corrected the hypercalcemia in this patient. Hence, this is the first study to our knowledge that identifies the interaction site of a disease-causing GPCR autoantibody working as its biased allosteric modulator and demonstrates that cinacalcet can correct the AHH autoantibody effects both in vitro and in our AHH patient. Our observations provide potentially new insights into how biased agonism works and how to design a biased allosteric modulator of a GPCR. Our observations also indicate that the diagnosis of AHH is important because the severity of hypercalcemia may become fatal if the autoantibody titer increases. Calcimimetics may serve as good treatment options for some patients with severe AHH.