Trends in Mineral Metabolism Treatment Strategies in Patients Receiving Hemodialysis in the United States

Comparative Effectiveness of Alternative Treatment Approaches to Secondary Hyperparathyroidism in Patients Receiving Maintenance Hemodialysis: An Observational Trial Emulation

RATIONALE & OBJECTIVE

Optimal approaches to treat secondary hyperparathyroidism (SHPT) in patients on maintenance hemodialysis (HD) have yet to be established in randomized controlled trials (RCTs).

STUDY DESIGN

Two observational clinical trial emulations.

SETTING & PARTICIPANTS

Both emulations included adults receiving in-center HD from a national dialysis organization. The patients who had SHPT in the period between 2009 and 2014, were insured for≥180 days by Medicare as primary payer, and did not have contraindications or poor health status limiting theoretical trial participation.

EXPOSURE

The parathyroid hormone (PTH) Target Trial emulation included patients with new-onset SHPT (first PTH 300-600pg/mL), with 2 arms defined as up-titration of either vitamin D sterols or cinacalcet within 30 days (lower target) or no up-titration (higher target). The Agent Trial emulation included patients with a PTH≥300 pg/mL while on≥6μg weekly of vitamin D sterol (paricalcitol equivalent dose) and no prior history of cinacalcet. The 2 arms were defined by the first dose or agent change within 30 days (vitamin D-favoring [vitamin-D was up-titrated] vs cinacalcet-favoring [cinacalcet was added] vs nondefined [neither applies]). Multiple trials per patient were allowed in trial 2.

OUTCOME

The primary outcome was all-cause death over 24 months; secondary outcomes included cardiovascular (CV) hospitalization or the composite of CV hospitalization or death.

ANALYTICAL APPROACH

Pooled logistic regression.

RESULTS

There were 1,152 patients in the PTH Target Trial (635 lower target and 517 higher target). There were 2,726 unique patients with 6,727 patient trials in the Agent Trial (6,268 vitamin D-favoring trials and 459 cinacalcet-favoring trials). The lower PTH target approach was associated with reduced adjusted hazard of death (HR, 0.71 [95% CI, 0.52-0.93]), CV hospitalization (HR, 0.78 [95% CI, 0.63-0.98]), and their composite (HR, 0.74 [95% CI, 0.61-0.89]). The cinacalcet-favoring approach demonstrated lower adjusted hazard of death compared to the vitamin D-favoring approach (HR, 0.79 [95% CI, 0.62-0.99]), but not of CV hospitalization or the composite outcome.

LIMITATIONS

Potential for residual confounding; low use of cinacalcet with low power.

CONCLUSIONS

SHPT management that is focused on lower PTH targets may lower mortality and CV disease in patients receiving HD. These findings should be confirmed in a pragmatic randomized trial.

PLAIN-LANGUAGE SUMMARY

Optimal approaches to treat secondary hyperparathyroidism (SHPT) have not been established in randomized controlled trials. Data from a national dialysis organization was used to identify patients with SHPT in whom escalated treatment may be indicated. The approach to treatment was defined based on observed upward titration of SHPT-controlling medications: earlier titration (lower target) versus delayed titration (higher target); and the choice of medication (cinacalcet vs vitamin D sterols). In the first trial emulation, we estimated a 29% lower rate of death and 26% lower rate of cardiovascular disease or death for patients managed with a lower versus higher target approach. Cinacalcet versus vitamin D-favoring approaches were not consistently associated with outcomes in the second trial emulation. This observational study suggests the need for additional clinical trials of SHPT treatment intensity.

Non calcium phosphate binders - Is there any evidence of benefit

PURPOSE OF REVIEW

Low-level evidence and opinion-based clinical practice guidelines highlight the substantial uncertainty in the practice patterns of hyperphosphatemia management in patients with chronic kidney disease (CKD). This manuscript reviews the evidence for the choice of phosphate binders and its impact on clinical outcomes.

RECENT FINDINGS

Phosphate binders are among the most common medications prescribed for patients on dialysis. Clinical practice guidelines recommend lowering phosphate levels toward normal range and restricting calcium-based binders in all CKD patients. There is substantial gap in the evidence underlying these recommendations with lack of any placebo-controlled, randomized trials showing survival benefits for any class of phosphate-binders. Despite the lack of evidence for specific phosphate target or if lowering phosphate improves survival, use of phosphate binders has remained central strategy in approach to hyperphosphatemia. Use of binders has added to the cost and contributed significant pill burden. Restriction of calcium-based binders to avoid positive calcium balance and consequent vascular calcification risk has a physiological rationale and weight of observational studies.

SUMMARY

There is currently no conclusive evidence that definitively guides the choice of any specific binders for management of hyperphosphatemia in patients with CKD. Use of noncalcium-based binders has a theoretical advantage in restricting total calcium intake to decrease the risk of vascular calcification but no proven benefits for mortality.

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.

Medication Burden and Prescribing Patterns in Patients on Hemodialysis in the USA, 2013-2017

INTRODUCTION

The medication burden of patients with end-stage renal disease (ESRD) on hemodialysis, a patient population with a high comorbidity burden and complex care requirements, is among the highest of any of the chronic diseases. The goal of this study was to describe the medication burden and prescribing patterns in a contemporary cohort of patients with ESRD on hemodialysis in the USA.

METHODS

We used the United States Renal Data System database from January 1, 2013, and December 31, 2017, to quantify the medication burden of patients with ESRD on hemodialysis aged ≥18 years. We calculated the average number of prescription medications per patient during each respective year (January-December), number of medications within classes, including potentially harmful medications, and trends in the number of medications and classes over the 5-year study period.

RESULTS

We included a total of 163,228 to 176,133 patients from 2013 to 2017. The overall medication burden decreased slightly, from a mean of 7.4 (SD 3.8) medications in 2013 to 6.8 (SD 3.6) medications in 2017. Prescribing of potentially harmful medications decreased over time (74.0% with at least one harmful medication class in 2013-68.5% in 2017). In particular, the prescribing of non-benzodiazepine hypnotics, benzodiazepines, and opioids decreased from 2013 to 2017 (12.2%-6.3%, 23.4%-19.3%, and 60.0%-53.4%, respectively). This trend was consistent across subgroups of age, sex, race, and low-income subsidy status.

CONCLUSIONS

Patients with ESRD on hemodialysis continued to have a high overall medication burden, with a slight reduction over time accompanied by a decrease in prescribing of several classes of harmful medications. Continued emphasis on assessment of appropriateness of high medication burden in patients with ESRD is needed to avoid exposure to potentially harmful or futile medications in this patient population.

Efficacy of Evocalcet in Previously Cinacalcet-Treated Secondary Hyperparathyroidism Patients

Introduction

Evocalcet is a recently approved calcimimetic agent for secondary hyperparathyroidism (SHPT). In this study, the efficacy and safety of once-daily oral evocalcet were evaluated in patients without prior cinacalcet use (nonusers) and previously treated patients (users).

Methods

This post hoc analysis of a previous phase III head-to-head comparison study included SHPT patients treated with evocalcet with or without prior cinacalcet use. Endpoints included trends in the median intact and whole parathyroid hormone (PTH), mean corrected calcium, phosphate, and bone metabolic markers, and whole-to-intact PTH ratios throughout the 30-week study period; proportions of patients achieving target intact PTH, corrected calcium, and phosphate at weeks 28 to 30; and adverse drug reactions (ADRs).

Results

This study included 127 nonusers and 190 users with significant differences in age; duration of dialysis; use of intravenous vitamin D receptor activators; levels of intact PTH, corrected calcium, tartrate-resistant acid phosphatase 5b, procollagen type 1 N-terminal-propeptide; and largest parathyroid gland volume (P < 0.05 for all characteristics) between 2 groups at baseline. Users required higher evocalcet dosages than nonusers. Similar efficacy results were found in the 2 groups except for a significantly higher proportion of nonusers achieving the intact PTH target (81.6% vs 67.1%, difference [95% confidence interval], −14.5% [−24.59, −3.34]), and a significant reduction in largest parathyroid gland volume from week 0 to week 30 (−120.6 [567.2] mm³, P = 0.043). No difference was found in ADRs between the 2 groups.

Conclusion

Treatment with evocalcet is effective and safe irrespective of prior cinacalcet treatment in SHPT patients.

The Association Between Dietary Inflammatory Index and Parathyroid Hormone in Adults With/Without Chronic Kidney Disease

Aims: We aimed to assess the association between dietary inflammation index (DII) with parathyroid hormone (PTH) and hyperparathyroidism (HP) in adults with/without chronic kidney disease (CKD).

Methods: Data were obtained from the 2003–2006 National Health and Nutrition Examination Survey (NHANES). The participants who were <18 years old, pregnant, or missing the data of DII, PTH, and CKD were excluded. DII was calculated based on a 24-h dietary recall interview for each participant. Weighted multivariable regression analysis and subgroup analysis were conducted to estimate the independent relationship between DII with PTH and the HP in the population with CKD/non-CKD.

Results: A total of 7,679 participants were included with the median DII of −0.24 (−2.20 to 1.80) and a mean PTH level of 43.42 ± 23.21 pg/ml. The average PTH was 45.53 ± 26.63 pg/ml for the participants in the highest tertile group compared with 41.42 ± 19.74 pg/ml in the lowest tertile group (P < 0.0001). The rate of HP was 11.15% overall, while the rate in the highest DII tertile was 13.28 and 8.60% in the lowest DII tertile (P < 0.0001). The participants with CKD tended to have higher PTH levels compared with their counterparts (61.23 ± 45.62 vs. 41.80 ± 19.16 pg/ml, P < 0.0001). A positive association between DII scores and PTH was observed (β = 0.46, 95% CI: 0.25, 0.66, P ≤ 0.0001), and higher DII was associated with an increased risk of HP (OR = 1.05, 95% CI: 1.02, 1.08, P = 0.0023). The results from subgroup analysis indicated that this association was similar in the participants with different renal function, gender, age, BMI, hypertension, and diabetes statuses and could also be appropriate for the population with CKD.

Conclusions: Higher consumption of a pro-inflammatory diet appeared to cause a higher PTH level and an increased risk of HP. Anti-inflammatory dietary management may be beneficial to reduce the risk of HP both in the population with and without CKD.