Effect of cinacalcet on cardiovascular disease in patients undergoing dialysis

Implications of Renal Disease in Patients Undergoing Structural Interventions

Percutaneous structural interventions have a major impact on the morbidity, mortality, and quality of life of patients by providing a lower-risk alternative to cardiac surgery. However, renal disease has a significant impact on outcomes of these interventions. This review explores the incidence, outcomes, pathophysiology, and preventative measures of acute kidney injury and chronic kidney disease on transcatheter aortic valve replacement, transcatheter mitral valve repair, and percutaneous balloon mitral valvuloplasty. Given the expanding indications for percutaneous structural interventions, further research is needed to identify ideal patients with chronic kidney disease or end-stage renal disease who would benefit from intervention.

Morbidity and long-term outcome of surgery for renal hyperparathyroidism: results from a prospective cohort

PURPOSES

Surgery remains an important treatment option for renal hyperparathyroidism (rHPT). The number of long-term outcome studies of parathyroidectomy is limited.

METHODS

All consecutive patients with a parathyroidectomy for rHPT between 09/2009 and 04/2021 in a Belgian tertiary referral hospital were prospectively enrolled. The main outcomes were (long-term) cured proportion and postoperative morbidity (hypocalcemia, recurrent laryngeal nerve (RLN) palsy, re-intervention for bleeding, and wound morbidity).

RESULTS

Sixty patients with a median age of 57 years were analyzed, including 23 patients before kidney transplantation, 23 patients without kidney transplantation, and 14 patients after kidney transplantation. Median time to transplant was 15 (6-24) months after parathyroidectomy. Morbidity was low with only two non-urgent returns to theatre (wound infection and non-compressive hematoma), two temporary RLN paralyses, and no 30-day mortality. Length of hospital stay was longer in patients with parathyroidectomy before kidney transplant, due to a more severe and prolonged need for calcium supplementation. After a median follow-up of 63 months, 37 patients (62%) were still alive, and 11 patients (18%) developed a recurrence.

CONCLUSIONS

This single-surgeon, single-center cohort with long-term follow-up confirms the safety and excellent 'cure' proportions of surgery for rHPT but stretches the importance of long-term follow-up.

The effect of intradialytic exercise on calcium, phosphorus and parathyroid hormone: a randomized controlled trial

BACKGROUND

Patients with kidney failure experience derangements of circulating markers of mineral metabolism and dysregulation of skeletal and cardiovascular physiology which results in high mortality rate in these patients. This study aimed to evaluate the effect of intradialytic exercise on regulation of these abnormalities in patients receiving chronic hemodialysis (HD).

METHODS

In this randomized controlled trial conducted in an HD center in Iran, adult patients receiving chronic HD were randomized to intradialytic exercise (60 min) in the second hour of thrice weekly dialysis for 6 months (intervention) or no intradialytic exercise (control). The primary outcomes were serum calcium, serum phosphorous and parathyroid hormone levels. Secondary outcomes were serum alkaline phosphatase and calcium-phosphorous product.

RESULTS

The study included 44 participants randomized to intervention (n = 22) or control (n = 22). During the 6-month intervention period, significant between-group changes were observed in all primary and secondary outcomes between the intervention and control groups. Statistical analyses reveal a significant increase in serum calcium (P < 0.05) as well as a significant decrease in serum phosphorous, parathyroid hormone, alkaline phosphatase and calcium-phosphorous product (P < 0.05).

CONCLUSION

Intradialytic exercise performed for at least 60 min during thrice weekly dialysis sessions improves bone mineral metabolism in adult patients receiving HD. Further studies should focus on observing and comparing the effect of different types of exercise on bone mineral disorders and all-cause mortality in HD patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04916743, Registered on 08/06/2021. Registered trial name: The Effect of Intradialytic Exercise on Calcium, Phosphorous and Parathyroid Hormone: A Randomized Controlled Trial.

Cardiovascular complications in chronic kidney disease: a review from the European Renal and Cardiovascular Medicine Working Group of the European Renal Association

Chronic kidney disease (CKD) is classified into five stages with kidney failure being the most severe stage (stage G5). CKD conveys a high risk for coronary artery disease, heart failure, arrhythmias, and sudden cardiac death. Cardiovascular complications are the most common causes of death in patients with kidney failure (stage G5) who are maintained on regular dialysis treatment. Because of the high death rate attributable to cardiovascular (CV) disease, most patients with progressive CKD die before reaching kidney failure. Classical risk factors implicated in CV disease are involved in the early stages of CKD. In intermediate and late stages, non-traditional risk factors, including iso-osmotic and non-osmotic sodium retention, volume expansion, anaemia, inflammation, malnutrition, sympathetic overactivity, mineral bone disorders, accumulation of a class of endogenous compounds called 'uremic toxins', and a variety of hormonal disorders are the main factors that accelerate the progression of CV disease in these patients. Arterial disease in CKD patients is characterized by an almost unique propensity to calcification and vascular stiffness. Left ventricular hypertrophy, a major risk factor for heart failure, occurs early in CKD and reaches a prevalence of 70-80% in patients with kidney failure. Recent clinical trials have shown the potential benefits of hypoxia-inducible factor prolyl hydroxylase inhibitors, especially as an oral agent in CKD patients. Likewise, the value of proactively administered intravenous iron for safely treating anaemia in dialysis patients has been shown. Sodium/glucose cotransporter-2 inhibitors are now fully emerged as a class of drugs that substantially reduces the risk for CV complications in patients who are already being treated with adequate doses of inhibitors of the renin-angiotensin system. Concerted efforts are being made by major scientific societies to advance basic and clinical research on CV disease in patients with CKD, a research area that remains insufficiently explored.

Randomized Controlled Clinical Trial of the Effect of Treatment with Vitamin K2 on Vascular Calcification in Hemodialysis Patients (Trevasc-HDK)

Introduction

Vitamin K deficiency among patients on hemodialysis (HD) affects the function of matrix GLA protein (MGP), a potent vitamin K-dependent inhibitor of vascular calcification (VC).

Methods

We conducted a single-center randomized controlled trial (RCT) on maintenance HD patients to examine if vitamin K2 supplementation can reduce progression of coronary artery calcification (CAC) over an 18-month study period. Patients were randomized to vitamin K2 group receiving menaquinone-7360 μg 3 times/wk or control group. The primary outcome was CAC scores at the end of the study period. The secondary outcomes were aortic valve calcification (AVC), carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx), dephosphorylated undercarboxylated MGP (dp-ucMGP) levels, major adverse cardiac events (MACE), and vascular access events.

Results

Of the 178 patients randomized, follow-up was completed for 138 patients. The CAC scores between the 2 groups were not statistically different at the end of 18 months (relative mean difference [RMD] 0.85, 95% CI 0.55-1.31). The secondary outcomes did not differ significantly in AVC (RMD 0.82, 95% CI 0.34-1.98), cfPWV (absolute mean difference [AMD] 0.55, 95% CI -0.50 to 1.60), and AIx (AMD 0.13, 95% CI -3.55 to 3.80). Supplementation with vitamin K2 did reduce dp-ucMGP levels (AMD -86, 95% CI -854 to -117). The composite outcome of MACE and mortality was not statistically different between the 2 groups (Hazard ratio = 0.98, 95% CI 0.50-1.94).

Conclusion

Our study did not demonstrate a beneficial effect of vitamin K2 in reducing progression of VC in this population at the studied dose and duration.

Recommendations of the Spanish Society of Nephrology for the management of mineral and bone metabolism disorders in patients with chronic kidney disease: 2021 (SEN-MM)

As in 2011, when the Spanish Society of Nephrology (SEN) published the Spanish adaptation to the Kidney Disease: Improving Global Outcomes (KDIGO) universal Guideline on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD), this document contains an update and an adaptation of the 2017 KDIGO guidelines to our setting. In this field, as in many other areas of nephrology, it has been impossible to irrefutably answer many questions, which remain pending. However, there is no doubt that the close relationship between the CKD-MBD/cardiovascular disease/morbidity and mortality complex and new randomised clinical trials in some areas and the development of new drugs have yielded significant advances in this field and created the need for this update. We would therefore highlight the slight divergences that we propose in the ideal objectives for biochemical abnormalities in the CKD-MBD complex compared to the KDIGO suggestions (for example, in relation to parathyroid hormone or phosphate), the role of native vitamin D and analogues in the control of secondary hyperparathyroidism and the contribution of new phosphate binders and calcimimetics. Attention should also be drawn to the adoption of important new developments in the diagnosis of bone abnormalities in patients with kidney disease and to the need to be more proactive in treating them. In any event, the current speed at which innovations are taking place, while perhaps slower than we might like, globally drives the need for more frequent updates (for example, through Nefrología al día).

Inverse correlation of intact PTH, oxidized PTH as well as non-oxidized PTH with 25-hydroxyvitamin D3 in kidney transplant recipients

Background

25-hydroxyvitamin D (25(OH)D) and potentially also 1,25-dihydroxyvitamin D (1,25(OH)2D) inhibits the synthesis of parathyroid hormone (PTH) in the chief cells of the parathyroid gland. Clinical studies showing a negative correlation between (25(OH)D and PTH are in good agreement with these findings in basic science studies. However, PTH was measured in these studies with the currently clinically used 2nd or 3rd generation intact PTH (iPTH) assay systems. iPTH assays cannot distinguish between oxidized forms of PTH and non-oxidized PTH. Oxidized forms of PTH are the by far most abundant form of PTH in the circulation of patients with impaired kidney function. Oxidation of PTH causes a loss of function of PTH. Given that the clinical studies done so far were performed with an PTH assay systems that mainly detect oxidized forms of PTH, the real relationship between bioactive non-oxidized PTH and 25(OH)D as well as 1,25(OH)2D is still unknown.

Methods

To address this topic, we compared for the first time the relationship between 25(OH)D as well as 1,25(OH)2D and iPTH, oxPTH as well as fully bioactive n-oxPTH in 531 stable kidney transplant recipients in the central clinical laboratories of the Charité. Samples were assessed either directly (iPTH) or after oxPTH (n-oxPTH) was removed using a column that used anti-human oxPTH monoclonal antibodies, a monoclonal rat/mouse parathyroid hormone antibody (MAB) was immobilized onto a column with 500 liters of plasma samples. Spearman correlation analysis and Multivariate linear regression were used to evaluate the correlations between the variables.

Results

There was an inverse correlation between 25(OH)D and all forms of PTH, including oxPTH (iPTH: r=-0.197, p<0.0001; oxPTH: r=-0.203, p<0.0001; n-oxPTH: r=-0.146, p=0.001). No significant correlation was observed between 1,25(OH)2D and all forms of PTH. Multiple linear regression analysis considering age, PTH (iPTH, oxPTH and n-oxPTH), serum calcium, serum phosphor, serum creatinine, fibroblast growth factor 23 (FGF23), osteoprotegerin (OPG), albumin, and sclerostin as confounding factors confirmed these findings. Subgroup analysis showed that our results are not affected by sex and age.

Conclusion

In our study, all forms of PTH are inversely correlated with 25-hydroxyvitamin D (25(OH)D). This finding would be in line with an inhibition of the synthesis of all forms of PTH (bioactive n-oxPTH and oxidized forms of PTH with minor or no bioactivity) in the chief cells of the parathyroid glad.

Progression of Vascular Calcification and Clinical Outcomes in Patients Receiving Maintenance Dialysis

Importance

Baseline findings from the China Dialysis Calcification Study (CDCS) revealed a high prevalence of vascular calcification (VC) among patients with end-stage kidney disease; however, data on VC progression were limited.

Objectives

To understand the progression of VC at different anatomical sites, identify risk factors for VC progression, and assess the association of VC progression with the risk of cardiovascular events and death among patients receiving maintenance dialysis.

Design, Setting, and Participants

This cohort study was a 4-year follow-up assessment of participants in the CDCS, a nationwide multicenter prospective cohort study involving patients aged 18 to 74 years who were undergoing hemodialysis or peritoneal dialysis. Participants were recruited from 24 centers across China between May 1, 2014, and April 30, 2015, and followed up for 4 years. A total of 1489 patients receiving maintenance dialysis were included in the current analysis. Data were analyzed from September 1 to December 31, 2021.

Exposures

Patient demographic characteristics and medical history; high-sensitivity C-reactive protein laboratory values; serum calcium, phosphorus, and intact parathyroid hormone (iPTH) values; and previous or concomitant use of medications.

Main Outcomes and Measures

The primary outcome was progression of VC at 3 different anatomical sites (coronary artery, abdominal aorta, and cardiac valves) and identification of risk factors for VC progression. Participants received assessments of coronary artery calcification (CAC), abdominal aortic calcification (AAC), and cardiac valve calcification (CVC) at baseline, 24 months, 36 months, and 48 months. Secondary outcomes included (1) the association between VC progression and the risk of all-cause death, cardiovascular (CV)-related death, and a composite of all-cause death and nonfatal CV events and (2) the association between achievement of serum calcium, phosphorus, and iPTH target levels and the risk of VC progression.

Results

Among 1489 patients, the median (IQR) age was 51.0 (41.0-60.0) years; 59.5% of patients were male. By the end of 4-year follow-up, progression of total VC was observed in 86.5% of patients; 69.6% of patients had CAC progression, 72.4% had AAC progression, and 33.4% had CVC progression. Common risk factors for VC progression at the 3 different anatomical sites were older age and higher fibroblast growth factor 23 levels. Progression of CAC was associated with a higher risk of all-cause death (model 1 [adjusted for age, sex, and body mass index]: hazard ratio [HR], 1.97 [95% CI, 1.16-3.33]; model 2 [adjusted for all factors in model 1 plus smoking status, history of diabetes, and mean arterial pressure]: HR, 1.89 [95% CI, 1.11-3.21]; model 3 [adjusted for all factors in model 2 plus calcium, phosphorus, intact parathyroid hormone, and fibroblast growth factor 23 levels and calcium-based phosphate binder use]: HR, 1.92 [95% CI, 1.11-3.31]) and the composite of all-cause death and nonfatal CV events (model 1: HR, 1.98 [95% CI, 1.19-3.31]; model 2: HR, 1.91 [95% CI, 1.14-3.21]; model 3: HR, 1.95 [95% CI, 1.14-3.33]) after adjusting for all confounding factors except the presence of baseline calcification. Among the 3 targets of calcium, phosphorus, and iPTH, patients who achieved no target levels (model 1: odds ratio [OR], 4.75 [95% CI, 2.65-8.52]; model 2: OR, 4.81 [95% CI, 2.67-8.66]; model 3 [for this analysis, adjusted for all factors in model 2 plus fibroblast growth factor 23 level and calcium-based phosphate binder use]: OR, 2.76 [95% CI, 1.48-5.16]), 1 target level (model 1: OR, 3.71 [95% CI, 2.35-5.88]; model 2: OR, 3.62 [95% CI, 2.26-5.78]; model 3: OR, 2.19 [95% CI, 1.33-3.61]), or 2 target levels (model 1: OR, 2.73 [95% CI, 1.74-4.26]; model 2: OR, 2.69 [95% CI, 1.71-4.25]; model 3: OR, 1.72 [95% CI, 1.06-2.79]) had higher odds of CAC progression compared with patients who achieved all 3 target levels.

Conclusions and Relevance

In this study, VC progressed rapidly in patients undergoing dialysis, with different VC types associated with different rates of prevalence and progression. Consistent achievement of serum calcium, phosphorus, and iPTH target levels was associated with a lower risk of CAC progression. These results may be useful for increasing patient awareness and developing appropriate strategies to improve the management of chronic kidney disease-mineral and bone disorder among patients undergoing dialysis.

Roles of PTH and FGF23 in kidney failure: a focus on nonclassical effects

Parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) each play a central role in the pathogenesis of chronic kidney disease-mineral and bone disorder (CKD-MBD). Both hormones increase as kidney function declines, presumably as a response to maintain normal phosphate balance, but when patients reach kidney failure, PTH and FGF23 fail to exert their phosphaturic effects, leading to hyperphosphatemia and further elevations in PTH and FGF23. In patients with kidney failure, the major target organ for PTH is the bone, but elevated PTH is also associated with mortality presumably through skeletal and nonskeletal mechanisms. Indeed, accumulated evidence suggests improved survival with PTH-lowering therapies, and a more recent study comparing parathyroidectomy and calcimimetic treatment further suggests a notion of "the lower, the better" for PTH control. Emerging data suggest that the link between SHPT and mortality could in part be explained by the action of PTH to induce adipose tissue browning and wasting. In the absence of a functioning kidney, the classical target organ for FGF23 is the parathyroid gland, but FGF23 loses its hormonal effect to suppress PTH secretion owing to the depressed expression of parathyroid Klotho. In this setting, experimental data suggest that FGF23 exerts adverse nontarget effects, but it remains to be confirmed whether FGF23 directly contributes to multiple organ injury in patients with kidney failure and whether targeting FGF23 can improve patient outcomes. Further efforts should be made to determine whether intensive control of SHPT improves clinical outcomes and whether nephrologists should aim at controlling FGF23 levels just as with PTH levels.

Treatment for secondary hyperparathyroidism focusing on parathyroidectomy

Secondary hyperparathyroidism (SHPT) is a major problem for patients with chronic kidney disease and can cause many complications, including osteodystrophy, fractures, and cardiovascular diseases. Treatment for SHPT has changed radically with the advent of calcimimetics; however, parathyroidectomy (PTx) remains one of the most important treatments. For successful PTx, removing all parathyroid glands (PTGs) without complications is essential to prevent persistent or recurrent SHPT. Preoperative imaging studies for the localization of PTGs, such as ultrasonography, computed tomography, and 99mTc-Sestamibi scintigraphy, and intraoperative evaluation methods to confirm the removal of all PTGs, including, intraoperative intact parathyroid hormone monitoring and frozen section diagnosis, are useful. Functional and anatomical preservation of the recurrent laryngeal nerves can be confirmed via intraoperative nerve monitoring. Total or subtotal PTx with or without transcervical thymectomy and autotransplantation can also be performed. Appropriate operative methods for PTx should be selected according to the patients' need for kidney transplantation. In the case of persistent or recurrent SHPT after the initial PTx, localization of the causative PTGs with autotransplantation is challenging as causative PTGs can exist in the neck, mediastinum, or autotransplanted areas. Additionally, the efficacy and cost-effectiveness of calcimimetics and PTx are increasingly being discussed. In this review, medical and surgical treatments for SHPT are described.

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

Rescue of High Glucose Impairment of Cultured Human Osteoblasts Using Cinacalcet and Parathyroid Hormone

Patients with type 2 diabetes mellitus (T2DM) experience a higher risk of fractures despite paradoxically exhibiting normal to high bone mineral density (BMD). This has drawn into question the applicability to T2DM of conventional fracture reduction treatments that aim to retain BMD. In a primary human osteoblast culture system, high glucose levels (25 mM) impaired cell proliferation and matrix mineralization compared to physiological glucose levels (5 mM). Treatment with parathyroid hormone (PTH, 10 nM), a bone anabolic agent, and cinacalcet (CN, 1 µM), a calcimimetic able to target the Ca²⁺-sensing receptor (CaSR), were tested for their effects on proliferation and differentiation. Strikingly, CN+PTH co-treatment was shown to promote cell growth and matrix mineralization under both physiological and high glucose conditions. CN+PTH reduced apoptosis by 0.9-fold/0.4-fold as measured by Caspase-3 activity assay, increased alkaline phosphatase (ALP) expression by 1.5-fold/twofold, increased the ratio of nuclear factor κ-B ligand (RANKL) to osteoprotegerin (OPG) by 2.1-fold/1.6-fold, and increased CaSR expression by 1.7-fold/4.6-fold (physiological glucose/high glucose). Collectively, these findings indicate a potential for CN+PTH combination therapy as a method to ameliorate the negative impact of chronic high blood glucose on bone remodeling.

Redefying the therapeutic strategies against cardiorenal morbidity and mortality: Patient phenotypes

Chronic kidney disease (CKD) patients face an unacceptably high morbidity and mortality, mainly from cardiovascular diseases. Diabetes mellitus, arterial hypertension and dyslipidemia are highly prevalent in CKD patients. Established therapeutic protocols for the treatment of diabetes mellitus, arterial hypertension, and dyslipidemia are not as effective in CKD patients as in the general population. The role of non-traditional risk factors (RF) has gained interest in the last decades. These entail the deranged clinical spectrum of secondary hyperparathyroidism involving vascular and valvular calcification, under the term "CKD-mineral and bone disorder" (CKD-MBD), uremia per se, inflammation and oxidative stress. Each one of these non-traditional RF have been addressed in various study designs, but the results do not exhibit any applied clinical benefit for CKD-patients. The "crusade" against cardiorenal morbidity and mortality in CKD-patients is in some instances, derailed. We propose a therapeutic paradigm advancing from isolated treatment targets, as practiced today, to precision medicine involving patient phenotypes with distinct underlying pathophysiology. In this regard we propose two steps, based on current stratification management of corona virus disease-19 and sepsis. First, select patients who are expected to have a high mortality, i.e., a prognostic enrichment. Second, select patients who are likely to respond to a specific therapy, i.e., a predictive enrichment.

Impact of Cinacalcet and Etelcalcetide on Bone Mineral and Cardiovascular Disease in Dialysis Patients

PURPOSES OF REVIEW

With chronic kidney disease (CKD) progression, secondary hyperparathyroidism (sHPT) and mineral and bone metabolism disease (MBD) almost inevitably develop and result in renal osteodystrophy and cardiovascular disease (CVD). Together with active vitamin D, calcimimetics are the main therapy for sHPT in CKD. This review provides an overview of the therapeutic effects of oral cinacalcet and intravenous etelcalcetide on CKD-MBD and vascular disease, with a focus on pediatric dialysis patients.

RECENT FINDINGS

Randomized controlled trials in adults and children demonstrate efficient lowering of parathyroid hormone (PTH) by the calcimimetics together with a reduction in serum calcium and phosphate when combined with low-dose active vitamin D, while therapy with active vitamin D analogs alone increases serum calcium and phosphate. Cinacalcet and etelcalcetide both improve bone formation and correct adynamic bone, i.e., have a direct bone anabolic effect. They decrease serum calciprotein particles, which are involved in endothelial dysfunction, atherogenesis, and vascular calcification. Clinical trials in adults suggest a modest slowing of the progression of cardiovascular calcification with cinacalcet. Calcimimetic agents represent a major pharmacological tool for improved control of CKD-MBD, by efficiently counteracting sHPT and allowing for better control of calcium/phosphate and bone homeostasis. Albeit definite evidence is lacking, the beneficial effects of calcimimetics on CVD are promising. Routine use of cinacalcet has been suggested in children.

Updates in the chronic kidney disease-mineral bone disorder show the role of osteocytic proteins, a potential mechanism of the bone-Vascular paradox, a therapeutic target, and a biomarker

The chronic kidney disease-mineral bone disorder (CKD-MBD) is a complex multi-component syndrome occurring during kidney disease and its progression. Here, we update progress in the components of the syndrome, and synthesize recent investigations, which suggest a potential mechanism of the bone-vascular paradox. The discovery that calcified arteries in chronic kidney disease inhibit bone remodeling lead to the identification of factors produced by the vasculature that inhibit the skeleton, thus providing a potential explanation for the bone-vascular paradox. Among the factors produced by calcifying arteries, sclerostin secretion is especially enlightening. Sclerostin is a potent inhibitor of bone remodeling and an osteocyte specific protein. Its production by the vasculature in chronic kidney disease identifies the key role of vascular cell osteoblastic/osteocytic transdifferentiation in vascular calcification and renal osteodystrophy. Subsequent studies showing that inhibition of sclerostin activity by a monoclonal antibody improved bone remodeling as expected, but stimulated vascular calcification, demonstrate that vascular sclerostin functions to brake the Wnt stimulation of the calcification milieu. Thus, the target of therapy in the chronic kidney disease-mineral bone disorder is not inhibition of sclerostin function, which would intensify vascular calcification. Rather, decreasing sclerostin production by decreasing the vascular osteoblastic/osteocytic transdifferentiation is the goal. This might decrease vascular calcification, decrease vascular stiffness, decrease cardiac hypertrophy, decrease sclerostin production, reduce serum sclerostin and improve skeletal remodeling. Thus, the therapeutic target of the chronic kidney disease-mineral bone disorder may be vascular osteoblastic transdifferentiation, and sclerostin levels may be a useful biomarker for the diagnosis of the chronic kidney disease-mineral bone disorder and the progress of its therapy.

Frequency and type of arrhythmia in Holter electrocardiogram in patients undergoing hemodialysis

Background/Aim: It is known that approximately 40% of chronic hemodialysis patients die due to cardiac arrhythmia and cardiovascular reasons. Determining whether the hemodialysis procedure poses a risk for arrhythmia is important in terms of prognostic follow-up of the patients. Therefore, we aimed to determine the underlying arrhythmia frequency and types with 24-hour Holter electrocardiogram (ECG) in patients receiving hemodialysis with normal baseline electrocardiography between the hemodialysis periods. Methods: Between January 2018 and January 2022, 91 consecutive patients who received hemodialysis for chronic renal failure (CRF) and applied to the cardiology outpatient clinic with complaints of palpitation and sinus rhythm on ECG and evaluated with 24-hour rhythm Holter ECG were included in the study. Our study was designed as a retrospective cohort study. Results: The mean age of the patient population was 65.78 (11.92) years, the mean systolic blood pressure was 143.71 (24.88) mmHg, and the mean heart rate was 83.43 (15.85) beats/min. Hypertension (HT) (n=44, 48%) and coronary artery disease (n=34, 37%) were the most common comorbid diseases. The most common arrhythmias detected on Holter ECG were ventricular extrasystole (VES) (n=18, 19.8%) and paroxysmal AF (n=8, 8.8%). Non-sustained ventricular tachycardia was detected in two patients. Conclusion: Detecting arrhythmia in the interdialytic periods in patients receiving hemodialysis due to CRF is important for follow-up and treatment. Even if the baseline ECG is normal in hemodialysis patients with CRF, the frequency of the underlying arrhythmia that needs to be treated is high.

Mineral Bone Disorders in Kidney Disease Patients: The Ever-Current Topic

Chronic kidney disease (CKD) is a complex and multifactorial disease, and one of the most prevalent worldwide. Chronic kidney disease-mineral bone disorders (CKD-MBD) with biochemical and hormonal alterations are part of the complications associated with the progression of CKD. Pathophysiology of CKD-MBD focused on abnormalities in serum levels of several biomarkers (such as FGF-23, klotho, phosphate, calcium, vitamin D, and PTH) which are discussed in this review. We therefore examine the prognostic association between CKD-MBD and the increased risk for cardiovascular events, mortality, and CKD progression to end-stage kidney disease (ESKD). Lastly, we present specific treatments acting on CKD to prevent and treat the complications associated with secondary hyperparathyroidism (SHPT): control of hyperphosphatemia (with dietary restriction, intestinal phosphate binders, and adequate dialysis), the use of calcimimetic agents, vitamin D, and analogues, and the use of bisphosphonates or denosumab in patients with osteoporosis.

A roadmap to parathyroidectomy for kidney transplant candidates

Chronic kidney disease mineral and bone disorder may persist after successful kidney transplantation. Persistent hyperparathyroidism has been identified in up to 80% of patients throughout the first year after kidney transplantation. International guidelines lack strict recommendations about the management of persistent hyperparathyroidism. However, it is associated with adverse graft and patient outcomes, including higher fracture risk and an increased risk of all-cause mortality and allograft loss. Secondary hyperparathyroidism may be treated medically (vitamin D, phosphate binders and calcimimetics) or surgically (parathyroidectomy). Guideline recommendations suggest medical therapy first but do not clarify optimal parathyroid hormone targets or indications and timing of parathyroidectomy. There are no clear guidelines or long-term studies about the impact of hyperparathyroidism therapy. Parathyroidectomy is more effective than medical treatment, although it is associated with increased short-term risks. Ideally parathyroidectomy should be performed before kidney transplantation to prevent persistent hyperparathyroidism and improve graft outcomes. We now propose a roadmap for the management of secondary hyperparathyroidism in patients eligible for kidney transplantation that includes the indications and timing (pre- or post-kidney transplantation) of parathyroidectomy, the evaluation of parathyroid gland size and the integration of parathyroid gland size in the decision-making process by a multidisciplinary team of nephrologists, radiologists and surgeons.

Role of Calcimimetics in Treating Bone and Mineral Disorders Related to Chronic Kidney Disease

Renal osteodystrophy is common in patients with chronic kidney disease and end-stage renal disease and leads to the risks of fracture and extraosseous vascular calcification. Secondary hyperparathyroidism (SHPT) is characterized by a compensatory increase in parathyroid hormone (PTH) secretion in response to decreased renal phosphate excretion, resulting in potentiating bone resorption and decreased bone quantity and quality. Calcium-sensing receptors (CaSRs) are group C G-proteins and negatively regulate the parathyroid glands through (1) increasing CaSR insertion within the plasma membrane, (2) increasing 1,25-dihydroxy vitamin D3 within the kidney and parathyroid glands, (3) inhibiting fibroblast growth factor 23 (FGF23) in osteocytes, and (4) attenuating intestinal calcium absorption through Transient Receptor Potential Vanilloid subfamily member 6 (TRPV6). Calcimimetics (CaMs) decrease PTH concentrations without elevating the serum calcium levels or extraosseous calcification through direct interaction with cell membrane CaSRs. CaMs reduce osteoclast activity by reducing stress-induced oxidative autophagy and improving Wnt-10b release, which promotes the growth of osteoblasts and subsequent mineralization. CaMs also directly promote osteoblast proliferation and survival. Consequently, bone quality may improve due to decreased bone resorption and improved bone formation. CaMs modulate cardiovascular fibrosis, calcification, and renal fibrosis through different mechanisms. Therefore, CaMs assist in treating SHPT. This narrative review focuses on the role of CaMs in renal osteodystrophy, including their mechanisms and clinical efficacy.

Renal hyperparathyroidism

The number of the patients with chronic kidney disease is now increasing in the world. The pathophysiology of renal hyperparathyroidism is closely associated with Klotho-FGF-endocrine axes, which must be solved definitively as early as possible. It was revealed that the expression of fgf23 is activated by calciprotein particles, which induces vascular ossification. And it is well known that phosphorus overload directly increases parathyroid hormone and hyperparathyroid bone disease develops in those subjects. On the other hand, low turnover bone disease is often recently. Both the patients with chronic kidney disease suffering from hyperparathyroid bone disease or low turnover bone disease are associated with increased fracture risk. Micropetrosis may be one of the causes of increased fracture risk in the subjects with low turnover bone disease. In this chapter, we now describe the diagnosis, pathophysiology and treatments of renal hyperparathyroidism.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Secondary and Tertiary Renal Hyperparathyroidism

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate treatment of secondary (SHPT) and tertiary (THPT) renal hyperparathyroidism.

BACKGROUND

Hyperparathyroidism is common among patients with chronic kidney disease, end-stage kidney disease, and kidney transplant. The surgical management of SHPT and THPT is nuanced and requires a multidisciplinary approach. There are currently no clinical practice guidelines that address the surgical treatment of SHPT and THPT.

METHODS

Medical literature was reviewed from January 1, 1985 to present January 1, 2021 by a panel of 10 experts in SHPT and THPT. Recommendations using the best available evidence was constructed. The American College of Physicians grading system was used to determine levels of evidence. Recommendations were discussed to consensus. The American Association of Endocrine Surgeons membership reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines present the epidemiology and pathophysiology of SHPT and THPT and provide recommendations for work-up and management of SHPT and THPT for all involved clinicians. It outlines the preoperative, intraoperative, and postoperative management of SHPT and THPT, as well as related definitions, operative techniques, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Preoperative and Perioperative Care, Surgical Planning and Parathyroidectomy, Adjuncts and Approaches, Outcomes, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal management of secondary and tertiary renal hyperparathyroidism.

Increasing rates of parathyroidectomy to treat secondary hyperparathyroidism in dialysis patients with Medicare coverage

BACKGROUND

Secondary hyperparathyroidism affects nearly all patients with renal failure on dialysis. Medical treatment of secondary hyperparathyroidism has considerably evolved over the past 2 decades, with parathyroidectomy reserved for severe cases. The primary objective of our study was to understand how trends in medical treatments affected parathyroidectomy rates in patients with secondary hyperparathyroidism on dialysis.

METHODS

We used the United States Renal Data System to identify 379,835 adult patients (age ≥18) who were on maintenance dialysis in the United States between 2006 and 2016 with Medicare as the primary payor and ascertained treatment for secondary hyperparathyroidism. Adjusted rate ratios for rates of parathyroidectomy were calculated using multivariable-adjusted Poisson regression.

RESULTS

Of 379,835 secondary hyperparathyroidism patients, 4,118 (1.1%) underwent parathyroidectomy, 39,835 (10.5%) received cinacalcet, 243,522 (64.1%) received phosphate binders, 17,571 (4.6%) received vitamin D analogs, and 86,899 (22.9%) received no treatment during the 10 years of follow-up. Over the entire study period, there was a 3.5-fold increase in the use of calcimimetics and a 3.4-fold increase in rates of parathyroidectomy. Compared to 2006 through 2009, utilization of parathyroidectomy increased 52% (adjusted rate ratio = 1.52, 95% confidence interval: 1.39-1.65) between 2010 and 2013 and by 106% (adjusted rate ratio = 2.06, 95% confidence interval: 1.90-2.24) between 2014 and 2016. The greatest increase in parathyroidectomy utilization occurred in younger patients (age 18-64 years), Black patients, female patients, those living in higher poverty neighborhoods, those listed for kidney transplant, and those who live in the Southern region of the United States.

CONCLUSION

Despite the evolution of medical treatments and an increase in the use of calcimimetics to treat secondary hyperparathyroidism, parathyroidectomy rates have been steadily increasing among dialysis patients with Medicare coverage.

Parathyroidectomy vs Cinacalcet Among Patients Undergoing Hemodialysis

CONTEXT

Parathyroidectomy (PTx) and cinacalcet are both effective treatments for secondary hyperparathyroidism in hemodialysis patients, but limited data exist comparing the long-term outcomes of these interventions.

OBJECTIVE

We aimed to compare the risk of mortality among hemodialysis patients who underwent PTx and those who started treatment with cinacalcet.

METHODS

In this prospective cohort study, comprising patients from the Japanese Society for Dialysis Therapy Renal Data Registry, patients who had intact parathyroid hormone (PTH) levels ≥ 300 pg/mL in late 2007 and underwent PTx or started treatment with cinacalcet in 2008 to 2009 were matched by propensity score at 1:3. PTx and cinacalcet were compared for all-cause mortality within 6 years.

RESULTS

Among eligible patients, 894 patients who underwent PTx were matched with 2682 patients who started treatment with cinacalcet. The median baseline intact PTH levels were 588 pg/mL and 566 pg/mL in the PTx and cinacalcet groups, respectively. PTx resulted in greater reductions in intact PTH, calcium, and phosphorus levels compared with cinacalcet. During the 6-year follow-up period, 201 patients (22.5%) in the PTx group and 736 patients (27.4%) in the cinacalcet group died. PTx was associated with a lower risk of mortality compared with cinacalcet (hazard ratio, 0.78 [95% CI, 0.67-0.91]; P = 0.002). This association was more pronounced in patients with intact PTH levels ≥ 500 pg/mL and in patients with serum calcium levels ≥ 10.0 mg/dL (both P for interaction < 0.001).

CONCLUSION

PTx compared with cinacalcet is associated with a lower risk of mortality, particularly among patients with severe secondary hyperparathyroidism.

First-in-Human Phase I Study of the Novel Injectable Calcimimetic Agent Upacicalcet in Healthy Adult Japanese Participants

Background and Objective

Upacicalcet sodium hydrate is a novel small-molecule calcimimetic and has potential as a therapeutic agent for secondary hyperparathyroidism. We assessed the pharmacokinetics, pharmacodynamics, safety, and tolerability of a single intravenous dose of upacicalcet in Japanese healthy adults.

Method

This was a single-center, double-blinded, randomized, placebo-controlled, dose-escalation study. For each cohort, eight subjects were randomly assigned at a ratio of 3:1 to receive a single injection of placebo or upacicalcet 0.01, 0.1, 1.0, or 2.5 mg.

Result

The plasma concentration of upacicalcet increased in a dose-dependent manner. Upacicalcet rapidly disappeared from plasma after administration. The half-life of upacicalcet was approximately 1–2 h. The major excretion route of upacicalcet was via urine. Serum intact parathyroid hormone decreased in accordance with the upacicalcet dose, from the lowest dose of 0.01 mg. Gastrointestinal disorders occurred in one patient in the 1.0 mg group and in five patients in the 2.5 mg group. All adverse events were nonserious, and no symptomatic hypocalcemia occurred.

Conclusion

This study showed that upacicalcet acted as a calcimimetic and was excreted in the urine unchanged with little metabolism. Moreover, upacicalcet is a small molecule and has a small volume of distribution. In addition, less than 50% of upacicalcet binds to human plasma proteins. These findings suggest that upacicalcet administered to patients undergoing hemodialysis might be expected to have a long excretion period and sustained pharmacological effect.

Vascular Calcification in Chronic Kidney Disease: An Update and Perspective

Chronic kidney disease is a devastating condition resulting from irreversible loss of nephron numbers and function and leading to end-stage renal disease and mineral disorders. Vascular calcification, an ectopic deposition of calcium-phosphate salts in blood vessel walls and heart valves, is an independent risk factor of cardiovascular morbidity and mortality in chronic kidney disease. Moreover, aging and related metabolic disorders are essential risk factors for chronic kidney disease and vascular calcification. Marked progress has been recently made in understanding and treating vascular calcification in chronic kidney disease. However, there is a paucity of systematic reviews summarizing this progress, and investigating unresolved issues is warranted. In this systematic review, we aimed to overview the underlying mechanisms of vascular calcification in chronic kidney diseases and discuss the impact of chronic kidney disease on the pathophysiology of vascular calcification. Additionally, we summarized potential clinical diagnostic biomarkers and therapeutic applications for vascular calcification with chronic kidney disease. This review may offer new insights into the pathogenesis, diagnosis, and therapeutic intervention of vascular calcification.

Etelcalcetide Versus Cinacalcet in Hemodialysis Patients in the United States: A Facility Calcimimetic Approach to Assess Real-World Effectiveness

Rationale & Objective

Some US hemodialysis (HD) facilities switched from oral cinacalcet to intravenous etelcalcetide as the primary calcimimetic therapy to control parathyroid hormone (PTH) levels after the introduction of etelcalcetide in 2017. Although clinical trials have demonstrated the superior efficacy of etelcalcetide versus cinacalcet, evidence comparing real-world effectiveness is lacking.

Study Design

Prospective cohort.

Setting & Participants

Patients receiving HD enrolled in US Dialysis Outcomes and Practice Patterns Study facilities.

Exposure

We classified HD facilities on the basis of whether >75% of calcimimetic users were prescribed etelcalcetide (“etelcalcetide-first”) or cinacalcet (“cinacalcet-first”) from March-August 2019.

Outcomes

PTH, calcium, and phosphorus levels among calcimimetic users, all averaged in the 6 months after the exposure assessment period.

Analytical Approach

We used adjusted linear regression to compare outcomes using 2 approaches: (1) cross-sectional comparison of etelcalcetide-first and cinacalcet-first HD facilities; (2) pre-post comparison of HD facilities that switched from cinacalcet-first to etelcalcetide-first using facilities that remained cinacalcet-first as a comparison group.

Results

We identified 45 etelcalcetide-first and 67 cinacalcet-first HD facilities; etelcalcetide-first (vs cinacalcet-first) facilities were more likely to be from small or independent dialysis organizations (86% vs 22%) and had higher total calcimimetic use (43% vs 29%) and lower active vitamin D use (66% vs 82%). In the cross-sectional analysis comparing etelcalcetide-first and cinacalcet-first HD facilities, the adjusted mean difference in PTH levels was −115 pg/mL (95% CI, −196 to −34) and the prevalence of a PTH level of >600 pg/mL was lower (prevalence difference, −11.4%; 95% CI, −19.3% to −3.5%). Among facilities that switched to etelcalcetide-first, the mean PTH level decreased from 671 to 484 pg/mL and the prevalence of a PTH level of >600 pg/mL decreased from 39% to 21%. Among facilities that remained cinacalcet-first, the mean PTH level increased from 632 to 698 pg/mL and the prevalence of a PTH level of >600 pg/mL increased from 37% to 43%. The adjusted difference-in-difference between the switch to etelcalcetide-first and the continuation of cinacalcet-first was −169 pg/mL (−249 to −90 pg/mL) for the mean PTH and −14.4% (−22.0% to −6.8%) for a PTH level of >600 pg/mL. We also observed slightly lower serum calcium levels and minimal differences in serum phosphorus levels between the etelcalcetide-first and the cinacalcet-first facilities.

Limitations

Residual confounding.

Conclusions

We observed better PTH control in HD facilities that switched from using cinacalcet to etelcalcetide as the primary calcimimetic therapy. Further research is needed to investigate how the greater real-world effectiveness of intravenous etelcalcetide (vs oral cinacalcet) may affect clinical outcomes.

Emerging cross-talks between chronic kidney disease-mineral and bone disorder (CKD-MBD) and malnutrition-inflammation complex syndrome (MICS) in patients receiving dialysis

Chronic kidney disease–mineral and bone disorder (CKD–MBD) is a systemic disorder that affects multiple organs and systems and increases the risk of morbidity and mortality in patients with CKD, especially those receiving dialysis therapy. CKD–MBD is highly prevalent in CKD patients, and its treatment is gaining attention from healthcare providers who manage these patients. Additional important pathologies often observed in CKD patients are chronic inflammation and malnutrition/protein-energy wasting (PEW). These two pathologies coexist to form a vicious cycle that accelerates the progression of various other pathologies in CKD patients. This concept is integrated into the term “malnutrition–inflammation–atherosclerosis syndrome” or “malnutrition–inflammation complex syndrome (MICS)”. Recent basic and clinical studies have shown that CKD–MBD directly induces inflammation as well as malnutrition/PEW. Indeed, higher circulating levels of inorganic phosphate, fibroblast growth factor 23, parathyroid hormone, and calciprotein particles, as markers for critical components and effectors of CKD–MBD, were shown to directly induce inflammatory responses, thereby leading to malnutrition/PEW, cardiovascular diseases, and clinically relevant complications. In this short review, we discuss the close interplay between CKD–MBD and MICS and emphasize the significance of simultaneous control of these two seemingly distinct pathologies in patients with CKD, especially those receiving dialysis therapy, for better management of the CKD/hemodialysis population.

Parathyroidectomy for dialysis patients in the era of calcimimetics: The surgeons' point of view

Calcimimetics is a new drug for lowering serum parathyroid hormone (PTH), calcium and phosphate in patients with hyperparathyroidism (HPT) on long-term dialysis. It became available on market in 2006. The impact of calcimimetics on the treatment by parathyroidectomy (PTx) was reviewed from the surgeons' point of view. Cure of renal HPT by calcimimetics is not feasible, but calcimimetics can improve preoperative cardiac ventricle ejection fractions by lowering serum PTH. Heart failure is not necessarily a contraindication for PTx. PTx should be done before irreversible organ damage occurs. Limb gangrenes is an ominous sign and should be prevented by frequent checkup for peripheral arterial circulation. The impact of renal osteodystrophy on the quality of life and as indirect cause of mortality deserves more attention in patients with renal HPT. Delayed referral to PTx leads to more complicated patients. A consensus between nephrologists and surgeons about propitious timing for PTx is necessary. Future prospect on the surgical treatment of renal HPT is proposed. Supplemental figure; http://links.lww.com/ASAIO/A782.

Non-Additive Effects of Combined NOX1/4 Inhibition and Calcimimetic Treatment on a Rat Model of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD)

Chronic kidney disease-mineral and bone disorder (CKD-MBD) increases cardiovascular calcification and skeletal fragility in part by increasing systemic oxidative stress and disrupting mineral homeostasis through secondary hyperparathyroidism. We hypothesized that treatments to reduce reactive oxygen species formation and reduce parathyroid hormone (PTH) levels would have additive beneficial effects to prevent cardiovascular calcification and deleterious bone architecture and mechanics before end-stage kidney disease. To test this hypothesis, we treated a naturally progressive model of CKD-MBD, the Cy/+ rat, beginning early in CKD with the NADPH oxidase (NOX1/4) inhibitor GKT-137831 (GKT), the preclinical analogue of the calcimimetic etelcalcetide, KP-2326 (KP), and their combination. The results demonstrated that CKD animals had elevated blood urea nitrogen, PTH, fibroblast growth factor 23 (FGF23), and phosphorus. Treatment with KP reduced PTH levels compared with CKD animals, whereas GKT treatment increased C-terminal FGF23 levels without altering intact FGF23. GKT treatment alone reduced aortic calcification and NOX4 expression but did not alter the oxidative stress marker 8-OHdG in the serum or aorta. KP treatment reduced aortic 8-OHdG and inhibited the ability for GKT to reduce aortic calcification. Treatments did not alter heart calcification or left ventricular mass. In the skeleton, CKD animals had reduced trabecular bone volume fraction and trabecular number with increased trabecular spacing that were not improved with either treatment. The cortical bone was not altered by CKD or by treatments at this early stage of CKD. These results suggest that GKT reduces aortic calcification while KP reduces aortic oxidative stress and reduces PTH, but the combination was not additive. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Coronary artery calcification progression and long-term cardiovascular outcomes in renal transplant recipients: an analysis by the joint model

Background

Compared with the general population, the risk of death is substantially higher in renal transplant recipients than in age- and sex-matched individuals in the general population. In the general population, coronary artery calcification (CAC) predicts all-cause and cardiovascular mortality. In this study we aimed to analyse these relationships in renal transplant recipients.

Methods

We examined 178 renal transplant patients in this prospective observational cohort study. We measured CAC with multidetector spiral computed tomography using the Agatston score at multiple time points. Overall, 411 scans were performed in 178 patients over an average 12.8 years follow-up. The clinical endpoint was a composite including all-cause death and non-fatal cardiovascular events. Data analysis was performed by the joint model.

Results

During a follow-up of 12.8 ± 2.4 years, coronary calcification progressed over time (P < 0.001) and the clinical endpoint occurred in 54 patients. In the analysis by the joint model, both the baseline CAC score and the CAC score progression were strongly associated with the incidence rate of the composite event [hazard ratio 1.261 (95% confidence interval 1.119–1.420), P = 0.0001].

Conclusions

CAC at baseline and coronary calcification progression robustly predict the risk of death and cardiovascular events in renal transplant recipients. These findings support the hypothesis that the link between the calcifying arteriopathy of renal transplant patients and clinical end points in these patients is causal in nature.

Management of endocrine surgical disorders during COVID-19 pandemic: expert opinion for non-surgical options

PURPOSE

The COVID-19 pandemic brought unprecedented conditions for overall health care systems by restricting resources for non-COVID-19 patients. As the burden of the disease escalates, routine elective surgeries are being cancelled. The aim of this paper was to provide a guideline for management of endocrine surgical disorders during a pandemic.

METHODS

We used Delphi method with a nine-scale Likert scale on two rounds of voting involving 64 experienced eminent surgeons and endocrinologists who had the necessary experience to provide insight on endocrine disorder management. All voting was done by email using a standard questionnaire.

RESULTS

Overall, 37 recommendations were voted on. In two rounds, all recommendations reached an agreement and were either endorsed or rejected. Endorsed statements include dietary change in primary hyperparathyroidism, Cinacalcet treatment in secondary hyperparathyroidism, alpha-blocker administration for pheochromocytoma, methimazole ± β-blocker combination for Graves' disease, and follow-up for fine-needle aspiration results of thyroid nodules indicated as Bethesda 3-4 cytological results and papillary microcarcinoma.

CONCLUSION

This survey summarizes expert opinion for the management of endocrine surgical conditions during unprecedented times when access to surgical treatment is severely disrupted. The statements are not applicable in circumstances in which surgical treatment is possible.

Parathyroidectomy Versus Cinacalcet for the Treatment of Secondary Hyperparathyroidism in Hemodialysis Patients

Background

Secondary hyperparathyroidism in patients with end stage renal disease on dialysis is associated with bone pain and fractures in addition to cardiovascular morbidity. Cinacalcet is the most commonly used drug to treat such patients, but it has never been compared to surgery. The goal of this study is to compare the long-term outcomes and survival between cinacalcet and parathyroidectomy in the treatment of secondary hyperparathyroidism in hemodialysis patients.

Methods

Adult patients on hemodialysis who were treated with cinacalcet or parathyroidectomy in the United States Renal Data System were included. Patients treated with surgery (n = 2023) were compared using 1:1 propensity score matching ratio to a cohort of patients treated with cinacalcet. A Cox regression analysis was conducted to compare the overall mortality.

Results

The propensity score matching successfully created two groups with similar demographics. Patients in the surgery group had a higher mean peak PTH level prior to therapy (2066.8 vs 1425.4, P < 0.001). No difference was observed in the development of new-onset coronary artery disease (7.7% vs 7.9%, P = 0.8) or cerebrovascular disease (7% vs 6.7%, P = 0.8). Surgical patients had a higher rate of pathologic fractures (27.8% vs 24.9%, P = 0.04). Survival analysis showed that patients undergoing surgery had a better 5-year survival (65.6% vs 57.8%) and were less likely to die within the study period (HR 0.77, 95% CI 0.7–0.85, P < 0.0001).

Conclusions

Patients on dialysis undergoing parathyroidectomy for the treatment of secondary hyperparathyroidism have a better overall survival than those treated with cinacalcet.

A molecular target of vascular calcification in chronic kidney disease

Vascular calcification (VC) causes cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD), particularly those with end-stage kidney disease (ESKD) on maintenance dialysis treatment. Although many mechanisms have been proposed, their detailed effects remain incompletely understood. In this issue of the JCI, Li et al. examined the molecular mechanism of the protective role of SIRT6 in VC in patients with CKD. Using in vitro and animal models of CKD, the authors demonstrated that SIRT6 prevents VC by suppressing the osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs). Mechanistically, SIRT6 bound and deacetylated the runt-related transcription factor 2 (Runx2), a key transcription factor for osteogenic differentiation, promoting its nuclear export for proteasome degradation. These studies provide a pathway in the pathogenesis of VC and justify investigating SIRT6 as a potential target in CKD.

Cinacalcet inhibition of neuronal action potentials preferentially targets the fast inactivated state of voltage-gated sodium channels

Voltage-gated sodium channel (VGSC) activation is essential for action potential generation in the brain. Allosteric calcium-sensing receptor (CaSR) agonist, cinacalcet, strongly and ubiquitously inhibits VGSC currents in neocortical neurons via an unidentified, G-protein-dependent inhibitory molecule. Here, using whole-cell patch VGSC clamp methods, we investigated the voltage-dependence of cinacalcet-mediated inhibition of VGSCs and the channel state preference of cinacalcet. The rate of inhibition of VGSC currents was accelerated at more depolarized holding potentials. Cinacalcet shifted the voltage-dependence of both fast and slow inactivation of VGSC currents in the hyperpolarizing direction. Utilizing a simple model, the voltage-dependence of VGSC current inhibition may be explained if the affinity of the inhibitory molecule to the channel states follows the sequence: fast-inactivated > slow-inactivated > resting. The state dependence of VGSC current inhibition contributes to the non-linearity of action potential block by cinacalcet. This dynamic and abundant signaling pathway by which cinacalcet regulates VGSC currents provides an important voltage-dependent mechanism for modulating central neuronal excitability.

A Systematic Review and Meta-analysis of Efficacy and Safety of Calcimimetic Agents in the Treatment of Secondary Hyperparathyroidism in Patients with Chronic Kidney Disease

BACKGROUND

Some reports have pointed out that calcimimetics agents are effective in the treatment of secondary hyperparathyroidism (SHPT) in chronic kidney disease (CKD) patients, but there is no detailed description of the advantages and disadvantages of calcimimetics agents of SHPT in CKD patients. We tried to pool the published data to verify the effectiveness of calcimimetics agents and to compare the advantages and disadvantages of cinacalcet compared with control in the treatment of SHPT in CKD patients.

METHODS

We included eligible studies of published papers from January 1st, 2000 to December 31st, 2020 in Medline, Pubmed and Web of science databases, and the data were extracted for this meta-analysis.

RESULTS

Twenty-seven studies were eligible, and all the included studies were randomized controlled trials (RCT) including patients treated with long-term dialysis. The results indicated that calcimimetic agents can reduce the parathyroid hormone (PTH, pg/ml) level (WMD = -178.22, 95% CI: -238.57, -117.86, P < 0.00001), calcium (Ca, mg/dl) level (WMD = -0.71, 95% CI: -0.86, -0.55, P < 0.00001), phosphorus (P, mg/dl) level (WMD = -0.32, 95% CI: -0.55, -0.08, P = 0.008), calcium-phosphorus product level (WMD = -7.73, 95% CI: -9.64, -5.82, P < 0.00001). Calcimimetic agents increased the bone alkaline phosphatase (BSAP, ng/ml) levels and rate of achieving target PTH, and reduced osteocalcin levels and the rate of parathyroidectomy. Calcimimetic agents increased the total adverse events' rate, the rate of hypocalcemia and gastrointestinal side effects (nausea, vomiting, abdominal pain and diarrhea), but there was no significant difference in serious adverse events between the calcimimetic agent group and control group.

CONCLUSION

Calcimimetic agents can reduce the PTH level, Ca level, P level, calcium-phosphorus product level and do not increase serious adverse events.

Activation of the Calcium Receptor by Calcimimetic Agents Is Preserved Despite Modest Attenuating Effects of Hyperphosphatemia

BACKGROUND

Phosphorus levels in the range seen clinically among patients undergoing dialysis have been reported to attenuate calcium receptor activation and modify parathyroid hormone (PTH) release from isolated parathyroid glands in vitro. Some clinicians and providers of dialysis thus have suggested that calcimimetic agents are ineffective and should not be used to manage secondary hyperparathyroidism among those undergoing dialysis when serum phosphorus concentrations exceed certain threshold levels.

METHODS

To determine whether hyperphosphatemia diminishes the therapeutic response to calcimimetic agents, we used data from large clinical trials to analyze the effects of etelcalcetide and cinacalcet to lower plasma PTH levels in individuals on hemodialysis who had secondary hyperparathyroidism and varying degrees of hyperphosphatemia.

RESULTS

Plasma PTH levels declined progressively during 26 weeks of treatment with either etelcalcetide or cinacalcet without regard to the degree of hyperphosphatemia at baseline. However, with each calcimimetic agent, the decreases in PTH from baseline were less at each interval of follow-up during the trials among participants with serum phosphorus levels above one of three prespecified threshold values compared with those with serum phosphorus levels below these thresholds.

CONCLUSIONS

These in vivo findings are the first in humans to support the idea that hyperphosphatemia attenuates calcium receptor activation by calcium ions and by calcimimetic agents. The effect of hyperphosphatemia on the responsiveness to calcimimetic agents appears relatively modest, however, and unlikely to be significant therapeutically. The efficacy of treatment with calcimimetic agents for lowering plasma PTH levels among those with secondary hyperparathyroidism remains robust despite substantial elevations in serum phosphorus.

Coronary Artery Disease in Chronic Kidney Disease: Need for a Heart-Kidney Team-Based Approach

Chronic kidney disease and coronary artery disease are co-prevalent conditions with unique epidemiological and pathophysiological features, that culminate in high rates of major adverse cardiovascular outcomes, including all-cause mortality. This review outlines a summary of the literature, and nuances pertaining to non-invasive risk assessment of this population, medical management options for coronary heart disease and coronary revascularisation. A collaborative heart-kidney team-based approach is imperative for critical management decisions for this patient population, especially coronary revascularisation; this review outlines specific periprocedural considerations pertaining to coronary revascularisation, and provides a proposed algorithm for approaching revascularisation choices in patients with end-stage kidney disease based on available literature.

Towards Personalized Therapy of Aortic Stenosis

Calcific aortic stenosis (CAS) is the most common cause of acquired valvular heart disease in adults with no available pharmacological treatment to inhibit the disease progression to date. This review provides an up-to-date overview of current knowledge of molecular mechanisms underlying CAS pathobiology and the related treatment pathways. Particular attention is paid to current randomized trials investigating medical treatment of CAS, including strategies based on lipid-lowering and antihypertensive therapies, phosphate and calcium metabolism, and novel therapeutic targets such as valvular oxidative stress, coagulation proteins, matrix metalloproteinases, and accumulation of advanced glycation end products.

Treatment practices and outcomes in incident peritoneal dialysis patients: the Swedish Renal Registry 2006-2015

BACKGROUND

Therapeutic developments have contributed to markedly improved clinical outcomes in peritoneal dialysis (PD) during the 1990s and 2000s. We investigated whether recent advances in PD treatment are implemented in routine Swedish care and whether their implementation parallels improved patient outcomes.

METHODS

We conducted an observational study of 3122 patients initiating PD in Sweden from 2006 to 2015. We evaluated trends of treatment practices (medications, PD-related procedures) and outcomes [patient survival, major adverse cardiovascular events (MACEs), peritonitis, transfer to haemodialysis (HD) and kidney transplantation] and analysed associations of changes of treatment practices with changes in outcomes.

RESULTS

Over the 10-year period, demographics (mean age 63 years, 33% women) and comorbidities remained essentially stable. There were changes in clinical characteristics (body mass index and diastolic blood pressure increased), prescribed drugs (calcium channel blockers, non-calcium phosphate binders and cinacalcet increased and the use of renin-angiotensin system inhibitors, erythropoietin and iron decreased) and dialysis treatment (increased use of automated PD, icodextrin and assisted PD). The standardized 1- and 2-year mortality and MACE risk did not change over the period. Compared with the general population, the risk of 1-year mortality was 4.1 times higher in 2006-2007 and remained stable throughout follow-up. However, the standardized 1- and 2-year peritonitis rate decreased and the incidence of kidney transplantation increased while transfers to HD did not change.

CONCLUSIONS

Over the last decade, treatment advances in PD patients were accompanied by a substantial decline in peritonitis frequency and an increased rate of kidney transplantations, while 1- and 2-year survival and MACE risk did not change.

Vascular Calcification in Chronic Kidney Disease: Distinct Features of Pathogenesis and Clinical Implication

Chronic kidney disease (CKD) is associated with a higher prevalence of vascular calcification (VC) and cardiovascular disease. VC in CKD patients showed different pathophysiological features from those of the general population. The pathogenesis of VC in CKD is a highly organized process, and prior studies have suggested that patients with CKD have their own specific contributors to the phenotypic change of vascular smooth muscle cells (VSMCs), including uremic toxins, CKD-mineral and bone disease (CKD-MBD), inflammation, and oxidative stress. For the diagnosis and monitoring of VC in CKD, several imaging modalities, including plain radiography, ultrasound, and computed tomography have been utilized. VC in CKD patients has distinct clinical features and implications. CKD patients revealed a more intense and more prevalent calcification on the intimal and medial layers, whereas intimal calcification is predominantly observed in the general population. While a higher VC score is clearly associated with a higher risk of all-cause mortality and cardiovascular events, a greater VC score in CKD patients does not fully reflect the burden of atherosclerosis, because they have more calcification at equal volumes of atheromatous plaques. The primary goal of VC treatment in CKD is the prevention of VC progression, and the main management is to control the biochemical components of CKD-MBD. Cinacalcet and non-calcium-containing phosphate binders are the mainstay of VC prevention in CKD-MBD management. VC in patients with CKD is an ongoing area of research and is expected to advance soon.

Association Between Treatment of Secondary Hyperparathyroidism and Posttransplant Outcomes

BACKGROUND

Secondary hyperparathyroidism (SHPT) affects nearly all patients on maintenance dialysis therapy. SHPT treatment options have considerably evolved over the past 2 decades but vary in degree of improvement in SHPT. Therefore, we hypothesize that the risks of adverse outcomes after kidney transplantation (KT) may differ by SHPT treatment.

METHODS

Using the Scientific Registry of Transplant Recipients and Medicare claims data, we identified 5094 adults (age ≥18 y) treated with cinacalcet or parathyroidectomy for SHPT before receiving KT between 2007 and 2016. We quantified the association between SHPT treatment and delayed graft function and acute rejection using adjusted logistic models and tertiary hyperparathyroidism (THPT), graft failure, and death using adjusted Cox proportional hazards; we tested whether these associations differed by patient characteristics.

RESULTS

Of 5094 KT recipients who were treated for SHPT while on dialysis, 228 (4.5%) underwent parathyroidectomy, and 4866 (95.5%) received cinacalcet. There was no association between treatment of SHPT and posttransplant delayed graft function, graft failure, or death. However, compared with patients treated with cinacalcet, those treated with parathyroidectomy had a lower risk of developing THPT (adjusted hazard ratio, 0.56; 95% confidence interval, 0.35-0.89) post-KT. Furthermore, this risk differed by dialysis vintage (Pinteraction = 0.039). Among patients on maintenance dialysis therapy for ≥3 y before KT (n = 3477, 68.3%), the risk of developing THPT was lower when treated with parathyroidectomy (adjusted hazard ratio, 0.43; 95% confidence interval, 0.24-0.79).

CONCLUSIONS

Parathyroidectomy should be considered as treatment for SHPT, especially in KT candidates on maintenance dialysis for ≥3 y. Additionally, patients treated with cinacalcet for SHPT should undergo close surveillance for development of tertiary hyperparathyroidism post-KT.

Secondary hyperparathyroidism and adverse health outcomes in adults with chronic kidney disease

BACKGROUND

Secondary hyperparathyroidism (sHPT) develops frequently in patients with chronic kidney disease (CKD). However, the burden and long-term impact of sHPT on the risk of adverse health outcomes are not well studied.

METHODS

We evaluated all adults receiving nephrologist care in Stockholm during 2006-11 who were not undergoing kidney replacement therapy and had not developed sHPT. Incident sHPT was identified by using clinical diagnoses, initiated medications or two consecutive parathyroid hormone (PTH) measurements ≥130 pg/mL. We characterized sHPT incidence by estimated glomerular filtration rate (eGFR) strata, evaluated clinical predictors and quantified the association between incident sHPT (time-varying exposure) and the risk of fractures, CKD progression, major adverse cardiovascular events (MACEs) and death.

RESULTS

We identified 2556 adults with CKD Stages 1-5 (mean age 66 years, 38% women), of whom 784 developed sHPT during follow-up. The incidence of sHPT increased with advancing CKD: from 57 cases/1000 person-years in CKD Stage G3 to 230 cases/1000 person-years in Stage G5. In multivariable analyses, low eGFR was the strongest sHPT predictor, followed by young age, male sex and diabetes. Incident sHPT was associated with a 1.3-fold (95% confidence interval 1.1-1.8) increased risk of death, a 2.2-fold (1.42-3.28) higher risk of MACEs, a 5.0-fold (3.5-7.2) higher risk of CKD progression and a 1.3-fold (1.5-2.2) higher risk of fractures. Results were consistent in stratified analyses and after excluding early events.

CONCLUSIONS

Our findings illustrate the burden of sHPT in advanced CKD and highlight the susceptibility for adverse outcomes of patients developing sHPT. This may inform clinical decisions regarding pre-sHPT risk stratification, PTH monitoring and risk-prevention strategies post-sHPT development.