Changes in 3-month mineral and bone disorder patterns were associated with all-cause mortality in prevalent hemodialysis patients with secondary hyperparathyroidism

The benefit of reduced serum phosphate levels depends on patient characteristics: a nationwide prospective cohort study

Background

In cohort studies of hyperphosphatemic hemodialysis patients, reduced serum phosphate levels have been linked to a lower mortality risk. To investigate whether this benefit is influenced by patient characteristics, we calculated the number needed to be exposed (NNE), stratified by patient characteristics.

Methods

In this 9-year prospective cohort study using the nationwide Japanese registry, we enrolled 78 256 hemodialysis patients aged 18 years or older. We investigated the relationship between time-averaged (TA) phosphate levels and mortality due to cardiovascular disease (CVD) using Cox proportional models. We estimated the 1-year NNE for CVD death in patients with baseline serum phosphate levels ≥6.0 mg/dL and exposure to TA phosphate levels decreasing to 3.5-<5.0 mg/dL using mixed-effects Poisson models.

Results

The hazard ratio of CVD mortality decreased linearly with lower serum TA phosphate levels in those with prior atherosclerotic CVD (ACVD) or diabetic nephropathy (DN) but plateaued with serum phosphate <5.0 mg/dL in those without. The hazard ratios (95% confidence interval) for phosphate ≥7.0 mg/dL compared with 3.5-<3.9 mg/dL were 1.58 (1.38-1.81) in those with prior ACVD, 1.91 (1.68-2.17) in those without, 1.87 (1.63-2.16) in those with DN and 1.65 (1.46-1.87) in those without. However, the NNE for one more person to benefit (NNEB) for CVD death was lower in patients with a history of ACVD than in those without (61 vs 118). Patients with DN had lower NNEB than those without (69 vs 113). In patients with TA albumin ≥3.8 g/dL, older patients had lower NNEB, while patients with TA albumin <3.45 g/dL showed no benefit in some groups, including the elderly.

Conclusions

The benefit of intensive phosphate management may be pronounced in patients with a history of ACVD or DN. A comprehensive approach that considers both age and nutritional status may be necessary when managing serum phosphate levels.

Education and cooking methods in the management of calcium and PTH serum levels in patients on hemodialysis: a randomized controlled study

BACKGROUND

Chronic kidney disease associated mineral bone disorder (CKD-MBD) is one of the major causes of excess morbidity and mortality in hemodialysis patients. The purpose of this study was to investigate whether education about dietary intakes and specific food processing methods affect serum calcium and PTH concentrations in hemodialysis patients.

METHODS

Forty-seven hemodialysis patients were randomly divided into a control and an intervention group. All participants were on individualized phosphate binder therapy. Both groups received education on dietary intake by a trained dietitian. The intervention group received additional education on specific preparation methods of different foodstuffs and consumed two hospital meals prepared according to these methods during hemodialysis. Serum calcium and PTH levels, and vitamin D analog therapy dosage were periodically monitored during the 1-year study period.

RESULTS

At the baseline of the study, there were no differences between control and intervention groups in serum calcium (p = 0.078), serum PTH (p = 0.670), and vitamin D analog therapy dosage (p = 0.184). At the end of the study, serum calcium was better regulated in the intervention group, resulting in a significant difference between the study groups (p = 0.013). This was also confirmed by serum PTH levels in the intervention group, which remained stable until the end of the study (p = 0.110).

DISCUSSION

Additional education on specific food processing techniques may result in improved management of serum calcium and PTH levels, which could ultimately provide better control of secondary hyperparathyroidism in hemodialysis patients.

Target phosphate and calcium levels in patients undergoing hemodialysis: a post-hoc analysis of the LANDMARK study

BACKGROUND

It is necessary to re-examine the optimal phosphate (P) and calcium (Ca) target values in the contemporary management of chronic kidney disease-mineral and bone disorder to reduce the risks of cardiovascular events in patients receiving hemodialysis.

METHODS

We performed a post-hoc analysis of the LANDMARK study. The outcomes were defined as cardiovascular events and all-cause death. Data from 2135 patients receiving hemodialysis at risk of vascular calcification were analyzed using a time-dependent Cox proportional hazard model adjusted for background factors.

RESULTS

On the hazard ratio (HR) curve, the ranges where the lower 95% confidence interval (CI) were below the minimum of HR (= 1.00) were as follows: P = 3.5-5.5 mg/dL; albumin-adjusted Ca < 9.1 mg/dL for cardiovascular events; and P = 3.6-5.3 mg/dL; albumin-adjusted Ca < 9.1 mg/dL for all-cause mortality. In stratified analysis, the HRs for cardiovascular events in P < 3.5 mg/dL and P ≥ 5.5 mg/dL were similar to that of P = 3.5-5.5 mg/dL (P ≥ 0.05), and albumin-adjusted Ca ≥ 9.1 mg/dL had higher HR than values < 9.1 mg/dL [1.30 (95% CI 1.00-1.68; P = 0.046)]. For all-cause mortality, the HR in P < 3.6 mg/dL was higher than that in P = 3.6-5.3 mg/dL [1.76 (95% CI 1.25-2.48; P = 0.001)], while the HRs between P ≥ 5.3 mg/dL and P = 3.6-5.3 mg/dL as well as those between albumin-adjusted Ca ≥ 9.1 and < 9.1 mg/dL were not significantly different (P ≥ 0.05).

CONCLUSIONS

Managing albumin-adjusted Ca < 9.1 mg/dL may reduce the cardiovascular risk among patients undergoing hemodialysis. Hypophosphatemia < 3.6 mg/dL may be associated with mortality.

Black patients are more likely to undergo parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

Prior studies have demonstrated racial disparities in the severity of secondary hyperparathyroidism among dialysis patients. Our primary objective was to study the racial and socioeconomic differences in the timing and likelihood of parathyroidectomy in patients with secondary hyperparathyroidism.

METHODS

We used the United States Renal Data System to identify 634,428 adult (age ≥18) patients who were on maintenance dialysis between 2006 and 2016 with Medicare as their primary payor. Adjusted multivariable Cox regression was performed to quantify the differences in parathyroidectomy by race.

RESULTS

Of this cohort, 27.3% (173,267) were of Black race. Compared to 15.4% of White patients, 23.1% of Black patients lived in a neighborhood that was below a predefined poverty level (P < .001). The cumulative incidence of parathyroidectomy at 10 years after dialysis initiation was 8.8% among Black patients compared to 4.3% among White patients (P < .001). On univariable analysis, Black patients were more likely to undergo parathyroidectomy (adjusted hazard ratio = 1.83; 95% confidence interval, 1.74-1.93). This association persisted after adjusting for age, sex, cause of end-stage renal disease, body mass index, comorbidities, dialysis modality, and poverty level (adjusted hazard ratio = 1.35; 95% confidence interval, 1.27-1.43). Therefore, patient characteristics and socioeconomic status explained 26% of the association between race and likelihood of parathyroidectomy.

CONCLUSION

Black patients with secondary hyperparathyroidism due to end-stage renal disease are more likely to undergo parathyroidectomy with shorter intervals between dialysis initiation and parathyroidectomy. This association is only partially explained by patient characteristics and socioeconomic factors.

Calcimimetic use in US hemodialysis facilities in first 2 years after the launch of etelcalcetide: A descriptive analysis of real-world clinical practice and outcomes

INTRODUCTION

This study described control of parathyroid hormone (PTH), phosphorus, and corrected calcium in adults initiating calcimimetics in small dialysis organizations after the introduction of etelcalcetide.

METHODS

This retrospective study using Visonex Clarity electronic health records between October 1, 2017, and December 31, 2019, identified adults ≥ 18 years of age receiving in-center hemodialysis as either a cinacalcet or etelcalcetide initiator based on their first calcimimetic use in 2018 (index date) with no prior calcimimetic use in the 3 months preindex date. Patients were stratified by PTH at index date and were followed for 15 months. Subcohorts of patients who were persistent on a single calcimimetic for 15 months and of patients who had their calcimimetic changed from cinacalcet to etelcalcetide were also analyzed.

FINDINGS

A total of 677 patients initiated cinacalcet and 711 initiated etelcalcetide. Mean PTH (pg/ml), phosphorus, and corrected calcium (mg/dl) at baseline were 864, 5.9, and 9.3 for cinacalcet and 804, 5.9, and 9.4 for etelcalcetide, respectively. During follow-up, the proportion of initiators considered in-target (monthly average PTH < 600) increased from 48% to 62% with cinacalcet and from 56% to 86% with etelcalcetide in the baseline PTH 600 to < 800 subgroup; increased from 30% to 64% with cinacalcet and 31% to 59% with etelcalcetide among those with baseline PTH 800 to < 1000; and increased from 14% to 41% with cinacalcet and 12% to 58% with etelcalcetide among those with baseline PTH ≥1000. A similar pattern was observed for persistent users (n = 646). For patients changed from cinacalcet to etelcalcetide (n = 183), the proportion of patients considered in-target increased from 22% in the month prior to the treatment change to 51% in Month 6 postchange.

DISCUSSION

Patients initiating calcimimetics at lower baseline PTH had better biochemical control than patients starting at higher PTH. Patients changed from cinacalcet to etelcalcetide had improvements in PTH control postchange.

Health Care Costs in Patients with and without Secondary Hyperparathyroidism in Spain

OBJECTIVE

To analyze the economic burden of secondary hyperparathyroidism (sHPT) in Spain by quantifying differences in costs of pharmacological treatments and associated cardiovascular events (CVE) between renal patients with and without sHPT.

METHODS

We used data collected in the NEFRONA cohort study and obtained treatment and CVE costs from the BOT PLUS database and Hospital Discharge Records in the Spanish Health System (CMBD-H), respectively. We examined data from 2445 renal patients followed during 2 years for chronic kidney disease (CKD) progression and 4 years for CVE, stratifying by presence of sHPT. Patient characteristics, administered treatments and CVE were directly extracted from NEFRONA registries. Dosage for each treatment regimen was assumed based on guidelines and multiplied by official unit costs to obtain treatment costs. Costs of CVE were based on ICD-9-CM.

RESULTS

Prevalence of sHPT in the cohort was 65.6% (63.6; 67.6). Average yearly pharmacological costs for patients without sHPT were 610.33€, while costs were 1483.17€ for sHPT patients (average increase of 143.0%). Two hundred three patients registered CVE, resulting in 4-year average costs of 582.57€ for non-sHPT patients compared to 941.87€ for sHPT patients (61.7% average increase). Bivariate analyses considering presence of dialysis, hypercalcemia or hyperphosphatemia and stratified by sHPT showed higher costs for sHPT patients.

CONCLUSIONS

These results show that sHPT is associated with substantially higher costs of both, pharmacological treatments and associated CVEs. Preventing the development of sHPT with early management in the course of CKD could possibly lead to better health outcomes and cost balance for health care systems.