Comparison of the Pharmacological Effects of Paricalcitol Versus Calcitriol on Secondary Hyperparathyroidism in the Dialysis Population

Effects of active vitamin D analogs and calcimimetic agents on PTH and bone mineral biomarkers in hemodialysis patients with SHPT: a network meta-analysis

OBJECTIVE

Active vitamin D analogs and calcimimetic agents are primary drugs for patients with secondary hyperparathyroidism. Due to the different pharmacological mechanisms, they have different effects on the level of parathyroid hormone, serum calcium, phosphorus, and bone turnover biomarkers. This study aimed to evaluate the active vitamin D analogs and calcimimetic agents in hemodialysis patients with secondary hyperparathyroidism.

METHODS

We included randomized clinical trials of hemodialysis patients with secondary hyperparathyroidism, comparing active vitamin D analogs to calcimimetic agents or placebo/control. The primary outcome was the change of PTH level from baseline to end-up. The secondary outcome was the change in serum calcium, phosphorus, calcium-phosphorus product, and bone turnover biomarkers. A network meta-analysis method was applied to complete this study. The forest plots reflected statistical differences in the outcomes between active vitamin D analogs and calcimimetic agents. The SUCRA result presented the ranking of impact on the outcomes.

RESULTS

Twenty-one randomized clinical trials with 4653 patients were included in this network meta-analysis. Global and splitting-node inconsistencies provided no evidence of inconsistency in this study. There was no statistical difference between two active vitamin D analogs and three calcimimetic agents in the PTH, and phosphorus levels changed. Considering serum calcium level, compared with placebo, calcitriol (9.73, 3.09 to 16.38) and paricalcitol (9.74, 3.87 to 15.60) increase serum calcium. However, cinacalcet (- 1.94, - 3.72 to - 0.15) and etelcalcetide (- 7.80, - 11.80 to - 3.80) reduced the serum calcium, even a joint use of cinacalcet with active vitamin D analogs (- 5.83, - 9.73 to - 1.93). Three calcimimetic agents decreased calcium levels much more than calcitriol and paricalcitol. The same type of drugs was not distinct, with each one affecting the change in calcium level. Cinacalcet reduced calcium-phosphorus product much more than paricalcitol (- 3.66, - 6.72 to - 0.60). Evocalcet decreased calcium-phosphorus product more than cinacalcet (- 5.64, - 8.91 to - 2.37), calcitriol (- 9.36, - 14.81 to - 3.92), and paricalcitol (- 9.30, - 13.78 to - 4.82). Compared with paricalcitol, cinacalcet significantly increases the level of ALP (24.50, 23.05 to 25.95) and bALP (0.67, 0.03 to 1.31). The incidence of gastrointestinal disorders in cinacacet (29.35, 1.71 to 504.98) and etelcalcetide (20.92, 1.20 to 365.68) was notably higher than in paricalcitol. Etelcalcetide (0.71, 0.53 to 0.96) and evocalcet (0.46, 0.33 to 0.64) presented a lower rate of gastrointestinal disorders than cinacalcet. Cinacalcet ranked first in adverse gastrointestinal, nervous, and respiratory reactions.

CONCLUSION

The same kinds of agents perform similar efficacy on the level of PTH, serum calcium, phosphorus, and calcium-phosphorus product. Paricalcitol did not lead to more hypercalcemia than calcitriol. The calcium decrease induced by cinacalcet was not settled even by associating it with active vitamin D analogs. Cinacalcet and evocalcet were superior to calcitriol and paricacitol in reducing calcium-phosphorus product. Calcimimetics induced more gastrointestinal disorders than active vitamin D analogs, especially cinacalcet.

Bariatric surgery and secondary hyperparathyroidism: a meta-analysis

BACKGROUND

Obesity increases the risk of obesity-related medical problems. Weight loss after metabolic and bariatric surgery (MBS) has been well studied. However, the effects of MBS on parathyroid function remain unclear.

OBJECTIVE

The objective of this study was to perform a meta-analysis to examine the impact of MBS on the risk of secondary hyperparathyroidism (SHPT).

SETTING

The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.

METHODS

The PubMed, Embase, Web of Science, and the Cochrane Library databases were systematically reviewed from inception to May 2022 to identify studies reporting quantitative measurements of SHPT risk pre-MBS and post-MBS. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were estimated and compared. Effects were pooled using a random-effects or fixed-effects model. Subgroup analyses were performed according to the follow-up time and surgical procedure.

RESULTS

The final meta-analysis included 9 studies with a total of 5585 patients. The mean follow-up time was 3.5 years (range 0.25-5). Overall, MBS appears to does not affect SHPT risk (OR = 1.34, 95% CI 0.81-2.20, I² = 95%). Follow-up data showed no evidence of SHPT within 2 years following gastric bypass (GB) and sleeve gastrectomy procedures (OR = 1.42, 95% CI 0.66-3.07 for GB, OR = 0.39, 95% CI 0.09-1.62 for sleeve gastrectomy ). At the 2-year and long-term follow-up intervals, a marked increase in SHPT was detected for GB (OR = 6.06, 95% CI 3.39-10.85 for GB). In addition, the surgical procedure for GB decreased the likelihood of SHPT compared with the surgical procedure for biliopancreatic diversion with duodenal switch (OR = 0.29, 95% CI 0.17-0.49).

CONCLUSIONS

Our meta-analysis indicated that GB appears to increase SHPT risk. Patients undergoing MBS should be aware of the risk of SHPT. Larger studies are needed to evaluate the outcomes and side effects and may eventually provide a better and more comprehensive understanding of the risks.

Balancing Altered Calcium Metabolism with Bone Health in Sarcoidosis

Abnormal calcium metabolism in sarcoidosis patients can lead to hypercalcemia, hypercalciuria, and kidney stones. Hypercalcemia in sarcoidosis is usually due to increased activity of 1α-hydroxylase in macrophages of pulmonary granulomata, resulting in low levels of 25-hydroxyvitamin D and high levels of calcitriol. Vitamin D supplementation may be dangerous for some sarcoidosis patients and is recommended only for those with decreased 25-hydroxyvitamin D and reduced or normal calcitriol level. Diagnosis, treatment of osteoporosis, and maintenance of bone health are complex issues for sarcoidosis patients. An approach to diagnosis and treatment of bone fragility is presented.

A comparative analysis of the efficacy and safety of paricalcitol versus other vitamin D receptor activators in patients undergoing hemodialysis: A systematic review and meta-analysis of 15 randomized controlled trials

Paricalcitol, a new vitamin D receptor activator (VDRA), is reported to be more effective than other VDRAs in reducing calcium and phosphorus levels in patients undergoing hemodialysis. However, the efficacy and safety of paricalcitol remain controversial. This analysis compares paricalcitol with other VDRAs in patients undergoing hemodialysis. We searched the Cochrane Library, PubMed, EMBASE, Web of Science, and CNKI up to April 22, 2019. Standardized mean difference (SMD), risk ratio (RR) and 95% confidence interval (CI) values were estimated to compare the outcomes of the groups. Two reviewers extracted data and assessed trial quality independently. All statistical analyses were performed using the standard statistical procedures of RevMan 5.2 and Stata 12.0. Fifteen studies (N = 110,544) were included in this meta-analysis. Of these studies, 11 were randomized controlled trials (RCTs) and 4 were non-randomized studies of interventions (NRSIs). Patients receiving paricalcitol experienced better overall survival (OS) than patients receiving other VDRAs, with a pooled hazard ratio of 0.86 (95% CI 0.80–0.91; P < 0.00001). Intact parathyroid hormone (iPTH) levels were significantly reduced in the paricalcitol group compared to the group receiving other VDRAs, with a pooled SMD of -0.53 (95% CI -0.89– -0.16; P = 0.004). There was a significant increase in serum calcium levels from baseline in the paricalcitol group compared to the other VDRAs group when limiting the analysis to RCTs, with a pooled SMD of 2.14 (95% CI 0.90–3.38; P = 0.0007). Changes in serum calcium levels were significantly lower in the paricalcitol group when the analysis was limited to NRSIs, with a pooled SMD of -0.85 (95% CI -1.34–-0.35; P = 0.0008). The NSRI analysis also showed a significant reduction in serum phosphorus levels in the paricalcitol group, with a pooled SMD of -0.57 (95% CI -1.00–-0.13; P = 0.01). No significant differences were observed in the incidence of hypercalcemia, hyperphosphatemia, or adverse events. Generally, paricalcitol seems superior to other VDRAs in reducing mortality and iPTH levels in patients undergoing hemodialysis. However, the comparative effectiveness of paricalcitol in reducing serum calcium and phosphorus levels needs further exploration. No significant difference was found in the rate of adverse events.

Management of Hyperphosphatemia in End-Stage Renal Disease: A New Paradigm

Bone and mineral metabolism becomes dysregulated with progression of chronic kidney disease (CKD), and increasing levels of parathyroid hormone serve as an adaptive response to maintain normal phosphorus and calcium levels. In end-stage renal disease, this response becomes maladaptive and high levels of phosphorus may occur. We summarize strategies to control hyperphosphatemia based on a systematic literature review of clinical trial and real-world observational data on phosphorus control in hemodialysis patients with CKD-mineral bone disorder (CKD-MBD). These studies suggest that current management options (diet and lifestyle changes; regular dialysis treatment; and use of phosphate binders, vitamin D, calcimimetics) have their own benefits and limitations with variable clinical outcomes. A more integrated approach to phosphorus control in dialysis patients may be necessary, incorporating measurement of multiple biomarkers of CKD-MBD pathophysiology (calcium, phosphorus, and parathyroid hormone) and correlation between diet adjustments and CKD-MBD drugs, which may facilitate improved patient management.

Efficacy and safety of paricalcitol in patients undergoing hemodialysis: a meta-analysis

Background

The elevated calcium and phosphorus levels in patients undergoing hemodialysis may increase the risk of all-cause mortality. Paricalcitol, as a new vitamin D receptor activator (VDRA), seemed to be effective in reducing the calcium and phosphorus levels.

Objectives

The aim of this study was to compare the efficacy and safety of paricalcitol with other VDRAs in patients undergoing hemodialysis.

Methods

PubMed, Embase, and Web of Science database were systematically reviewed.

Selection criteria

Studies that focused on the use of paricalcitol for hemodialysis patients were eligible for inclusion.

Data collection and analysis

Two independent investigators performed the literature search, data extraction, and assessment of methodological quality. The outcomes were expressed with standard mean difference (SMD), HR, or risk ratio (RR) with 95% CI.

Results

Thirteen studies involving 112,695 patients were included in this meta-analysis. Among these studies, four studies were cohort studies and nine studies were randomized controlled trials (RCTs). For cohort studies, they were regarded as being of high quality; for RCTs, only one was classified as being at low risk of bias; and the remaining eight studies were at being unclear risk of bias. Compared with other VDRAs, paricalcitol significantly improved the overall survival (HR =0.86, 95% CI: 0.80, 0.92; P<0.001) and reduced the intact parathyroid hormone (iPTH) (SMD =-0.53, 95% CI: -0.90, -0.17; P=0.004). Paricalcitol offered similar effect with other VDRAs in the control of calcium (SMD =0.32, 95% CI: -0.04, 0.67; P=0.078) and phosphorus (SMD =0.06, 95% CI: -0.26, 0.37; P=0.727) levels. However, the serum change in calcium phosphate product was greater in the paricalcitol group than in the other VDRA group (SMD =2.13, 95% CI: 0.19, 4.07; P=0.031). There was no significant difference in the incidence of adverse events between the two groups (RR =1.02, 95% CI: 0.93, 1.12; P=0.674).

Conclusion

Paricalcitol was crucial in reducing the mortality in patients undergoing hemodialysis. Moreover, both paricalcitol and other VDRAs were effective in control of the serum iPTH, calcium, and phosphorus levels. Given the potential limitations in this study, more prospective large-scale, well-conducted RCTs are needed to confirm these findings.

Active Vitamin D in Chronic Kidney Disease: Getting Right Back Where We Started from?

BACKGROUND

The vitamin D system is essential for optimal health in humans. Circulating calcitriol, a key metabolite in maintaining calcium and phosphorus homeostasis, is produced in the kidney. In kidney failure, calcitriol levels progressively decrease, contributing to the development of renal secondary hyperparathyroidism (SHPT).

SUMMARY

For years, SHPT had a central role in the disturbed mineral metabolism of renal patients. As calcitriol deficiency contributes to SHPT development, treatment with calcitriol or other compounds able to activate the vitamin D receptor (VDR) was one of the mainstays of therapy for renal patients in the last 40 years. In this review, we discuss how the treatment with VDR activators (VDRA) evolved during this time in the United States, as well as the main factors responsible for these changes.

KEY MESSAGES

Management of SHPT with VDRA in renal patients has undergone a few paradigm shifts over the last 40 years. When treating SHPT, the newly developed therapies as well as VDRA need to be carefully considered and used appropriately. Nephrologists need to use an integrated approach that avoids excessive use of VDRA, ensures replenishment of vitamin D stores, and avoids hypercalcemia and hyperphosphatemia.

Comparison of Paricalcitol and Calcitriol in Dialysis Patients With Secondary Hyperparathyroidism: A Meta-Analysis of Randomized Controlled Studies

Paricalcitol and calcitriol are widely used for the treatment of secondary hyperparathyroidism in dialysis patients. We conducted a systematic review and meta-analysis to compare the efficacy and safety of paricalcitol and calcitriol for secondary hyperparathyroidism in dialysis patients. PubMed, EMbase, Web of Science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCT) assessing the efficacy of paricalcitol and calcitriol for secondary hyperparathyroidism in dialysis patients are included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. Meta-analysis was carried out using the random-effect model. Six randomized controlled trials are included in the meta-analysis. Overall, compared with calcitriol treatment for secondary hyperparathyroidism in dialysis patients, paricalcitol treatment has comparable ≥50% reduction of parathyroid hormone (risk ratio [RR] = 1.33; 95% CI = 0.93-1.91; P = 0.12), calcium concentration (standard mean difference [Std. MD] = -0.21; 95% CI = -0.94 to 0.52; P = 0.58), phosphate concentration (Std. MD = -0.17; 95% CI = -0.58 to 0.24; P = 0.42), calcium phosphate (Std. MD = -0.08; 95% CI = -0.49-0.34; P = 0.71), alkaline phosphatase (Std. MD = -0.21; 95% CI = -0.73-0.31; P = 0.43), hypercalcemia (RR = 1.43; 95% CI = 0.51 to 3.98; P = 0.49), adverse events (RR = 0.79; 95% CI = 0.42-1.49; P = 0.47), and serious adverse events (RR = 0.78; 95% CI = 0.47-1.30; P = 0.33). Paricalcitol and calcitriol result in similar ≥50% reduction of parathyroid hormone, calcium concentration, phosphate concentration, calcium phosphate, alkaline phosphatase, hypercalcemia, adverse events, and serious adverse events for secondary hyperparathyroidism in dialysis patients.

Comparative efficacy and safety of paricalcitol versus vitamin D receptor activators for dialysis patients with secondary hyperparathyroidism: a meta-analysis of randomized controlled trials

Background

Secondary hyperparathyroidism (SHPT) is a severe complication for dialysis patients. Vitamin D receptor activators (VDRAs) are used to treat SHPT, but the comparative efficacy and safety between paricalcitol and other vitamin D receptor activators for management of SHPT in dialysis patients has been unproven.

Methods

We searched PubMed, Embase, and the Cochrane Library for the time period through June 2017 to identify randomized controlled trials that evaluated paricalcitol compared with other VDRAs for treatment of SHPT. The primary outcome was the percentage of patients with target reduction of intact parathyroid hormone (iPTH) from baseline. Secondary outcomes included incidences of hypercalcemia and hyperphosphatemia. The random-effects model was used to estimate relative risks (RRs) with 95% confidence intervals (CIs).

Results

Eight studies (N = 759) were eligible for final inclusion. Compared with other VDRAs, no significant differences were found in the percentage of patients with target reduction of intact parathyroid hormone (iPTH) from baseline for paricalcitol treatment of SHPT in dialysis patients (RR, 1.01; 95% CI, 0. 87–1.18; p = 0.85). There were no differences in the incidence of hypercalcemia (RR, 0.95; 95% CI, 0.74–1.21; p = 0. 65) and hyperphosphatemia (RR, 0.94; 95% CI, 0.77–1.16; p = 0.58).

Conclusions

The presently available evidence is insufficient to draw a conclusion regarding whether paricalcitol therapy has a comparative efficacy and safety over other VDRAs for treating dialysis patients with SHPT. Large-sample, well-conducted, high-quality RCTs with patient-level outcomes (i.e., mortality) are urgently needed.

Electronic supplementary material

The online version of this article (10.1186/s12882-017-0691-6) contains supplementary material, which is available to authorized users.

Secondary Hyperparthyroidism: Pathogenesis, Diagnosis, Preventive and Therapeutic Strategies

Uremic secondary hyperparathyroidism is a multifactorial and complex disease often present in advanced stages of chronic kidney disease. The accumulation of phosphate, the increased FGF23 levels, the reduction in active vitamin D production, and the tendency to hypocalcemia are persistent stimuli for the development and progression of parathyroid hyperplasia with increased secretion of PTH. Parathyroid proliferation may become nodular mainly in cases of advanced hyperparathyroidism. The alterations in the regulation of mineral metabolism, the development of bone disease and extraosseous calcifications are essential components of chronic kidney disease-mineral and bone disorder and have been associated with negative outcomes. The management of hyperparathyroidism includes the correction of vitamin D deficiency and control of serum phosphorus and PTH without inducing hypercalcemia. An update of the leading therapeutic tools available for the prevention and clinical management of secondary hyperparathyroidism, its diagnosis, and the main mechanisms and factors involved in the pathogenesis of the disease will be described in this review.