Treatment of secondary hyperparathyroidism in haemodialysis patients: a randomised clinical trial comparing paricalcitol and alfacalcidol

Evaluation of osseous changes in dental panoramic radiography using radiomorphometric indices in patients with hyperthyroidism

OBJECTIVE

The aim of the present study was to compare radiomorphometric measurements on panoramic images of patients with hyperthyroidism (HT) to those of a control population.

STUDY DESIGN

In this retrospective study, the mental index (MI), inferior panoramic mandibular index (PMI), antegonial index (AI), gonial index (GI), and mandibular cortical index (MCI) were evaluated on dental panoramic radiographs (DPRs) of 40 patients with HT and 40 healthy age- and sex-matched individuals and compared between the groups. Quantitative data (MI, PMI, AI, and GI) were analyzed with the Student t and Mann-Whitney U tests. Categorical data (MCI) were analyzed with the chi-square test.

RESULTS

Statistically significant differences between the patient and control groups were found for inferior PMI (P = .001) and AI (P = .017) values, with smaller mean values among the patients. However, the measurements of MI (P = .59) and GI (P = .164) and the MCI distribution (P = .13) were similar in both groups.

CONCLUSIONS

Evaluating the radiomorphometric indices of inferior PMI and AI on the DPRs of patients with HT who are at high risk of secondary osteoporosis could be helpful in the early diagnosis of osteoporotic changes and in formulating surgical treatment plans.

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.

Evaluation of renal osteodystrophy in the dental clinic by assessment of mandibular and phalangeal cortical indices

OBJECTIVES

Secondary hyperparathyroidism (SHPT) is a disease that affects patients with chronic kidney disease, and is characterized by mineral disturbance and bone loss, known as renal osteodystrophy. The aim of this study was to assess the validity of using intraoral phosphor storage plates to take radiographs of the middle phalanges to evaluate bone loss resulting from SHPT during follow-up of these patients.

METHODS

The sample consisted of 24 patients with chronic kidney disease, 12 with parathyroid hormone (PTH) levels ≥500 pg/ml, and 12 with PTH levels <500 pg/ml, who underwent hemodialysis weekly. For each patient, a panoramic radiograph and digital radiographs of the ring, index, and middle fingers of both hands were taken. The Mandibular Cortical Index (MCI) and the Trabecular Bone Pattern Index (TBP) were applied to the panoramic radiographs, while the Phalangeal Cortical Index (PCI) was applied to the digital radiographs of the phalanges. Three evaluators performed all analyses.

RESULTS

Significant correlations were found between the PTH levels and the MCI (p = 0.023), the PCI (p = 0.039) and the TBP index (p = 0.032). These parameters were also significantly interrelated (MCI × PCI = 0.001; MCI × TBP = 0.004 and PCI × TBP = 0.009). The PCI was shown to have the highest correlation with PTH levels.

CONCLUSION

In patients with chronic renal disease, it is clinically relevant to use panoramic and digital radiographs using intraoral storage plates to assess a number of quantitative parameters that can be linked to PTH levels.

Changes in jawbones of male patients with chronic renal failure on digital panoramic radiographs

OBJECTIVE

To compare the existence of gonial cortical bone thickness, antegonial index, mandibular canal bone resorption and gonial angle values and pathologies like ground-glass appearance in jawbones and brown tumor in male patients undergoing dialysis due to chronic renal failure and men from the healthy control group on panoramic radiographs.

MATERIALS AND METHODS

Panoramic radiographs were taken from 80 male individuals in total (40 normal and 40 dialysis patients). Values obtained from the right and left sides of the mandible were summed and their means were calculated. Gonial cortical thickness, antegonial index and gonial angle values were assessed with the Student's t-test, mandibular canal wall resorption with the Chi-square test, and pathologies such as ground-glass appearance and Brown tumor as "available" or "not available."

RESULTS

Statistically significant differences were observed among the antegonial index (P < 0.001), gonial cortical bone thickness (P < 0.001), and gonial angle (P < 0.001) values of study and control groups. Besides, mandibular canal wall resorption (P < 0.001) was also statistically significant. In the study group, pathologies with ground-glass appearance were encountered in mandible, but no radiographic findings were observed similar to brown tumor.

CONCLUSIONS

Compared to the control group, decreases were found in gonial cortical bone thicknesses, antegonial index values, mandibular canal wall resorption, and gonial angle values of the patients receiving dialysis treatment due to chronic renal failure. Although it is not statistically significant, pathology with ground-glass appearance was detected in a patient, but no pathologies like brown tumor were observed. These findings from patients with chronic renal failure must be evaluated in panoramic radiography.

The uses and abuses of Vitamin D compounds in chronic kidney disease-mineral bone disease (CKD-MBD)

Vitamin D is of paramount importance to skeletal development, integrity and health. Vitamin D homeostatis is typically deranged in a number of chronic conditions, of which chronic kidney disease is one of the most important. The use of vitamin D based therapy to target secondary hyperparathyroidism is now several decades old, and there is a large body of clinical practice, experience, guidelines and research to underpin this. However, there are many unknowns, of significant clinical relevance. Amongst which is what "species" of vitamin D we should be using, in what patient, and, under what conditions. Sadly, there has been a real dearth of randomised controlled trials, and trials with outputs of clinical relevance, which means our clinical practice has not developed and refined adequately ove the last 4 decades. This article will discuss the vexed but critical questions of which vitamin D therapies might suit which kidney patients, and will high-light the many important clinical questions which urgently require answering.

The influence of vitamin D analogs on calcification modulators, N-terminal pro-B-type natriuretic peptide and inflammatory markers in hemodialysis patients: a randomized crossover study

Background

The risk of cardiovascular disease is tremendously high in dialysis patients. Dialysis patients treated with vitamin D analogs show decreased cardiovascular morbidity and mortality compared with untreated patients. We examined the influence of two common vitamin D analogs, alfacalcidol and paricalcitol, on important cardiovascular biomarkers in hemodialysis patients. Anti-inflammatory effects and the influence on regulators of vascular calcification as well as markers of heart failure were examined.

Methods

In 57 chronic hemodialysis patients enrolled in a randomized crossover trial comparing paricalcitol and alfacalcidol, we examined the changes in osteoprotegerin, fetuin-A, NT-proBNP, hs-Crp, IL-6 and TNF-α, during 16 weeks of treatment.

Results

NT-proBNP and osteoprotegerin increased comparably in the paricalcitol and alfacalcidol-treated groups. Fetuin-A increased significantly in the alfacalcidol-treated group compared with the paricalcitol-treated group (difference 32.84 μmol/l (95% C.I.; range 0.21–67.47)) during the first treatment period. No difference was found between the groups during the second treatment period, and IL-6, TNF-α and hs-Crp were unchanged in both treatment groups.

Conclusions

Paricalcitol and alfacalcidol modulate regulators of vascular calcification. Alfacalcidol may increase the level of the calcification inhibitor fetuin-A. We did not find any anti-inflammatory effect or difference in changes of NT-proBNP.

Trial registry

ClinicalTrials.gov NCT00469599 May 3 2007.

Severe secondary hyperparathyroidism and panoramic radiography parameters

OBJECTIVES

Renal osteodystrophy (RO) are skeletal abnormalities seen in patients with secondary hyperparathyroidism (SHPT). This study aims to evaluate the effects of RO using panoramic radiography parameters. Furthermore, the correlation between these parameters and parathyroid hormone (PTH) levels was tested.

MATERIALS AND METHODS

Qualitative (mandibular cortical index/trabecular bone pattern) and quantitative parameters (mental index/calcification and resorption foci) were applied from panoramic radiographs of chronic kidney disease (CKD) patients and controls. Frequency distribution and descriptive analysis were used to compare the results of both groups. Spearman's correlation coefficient evaluated the correlation between serum PTH levels of CKD patients and the radiographic parameters. Intra- and interobserver agreement was tested using the intraclass correlation coefficient and kappa index.

RESULTS

Intra- and interobserver agreement was respectively excellent (0.81-1.00) and good (0.61-0.80). Qualitative parameters demonstrate significant difference compared with the control group. Mean mental index was lower in patients with CKD (3.17 ± 1.35 mm), but the difference was not significant. Calcification/resorption foci (3.63 ± 2.07) of CKD patients were significantly more present than in the control group (p = 0.0001). PTH levels were correlated with mental index, mandibular cortical index and trabecular bone pattern (respectively, 0.0034, 0.0315, and 0.0370).

CONCLUSIONS

RO presented a number of characteristic bone metabolic effects in the jaws that could be observed on panoramic radiographs. Radiographs of CKD patients demonstrate significantly more calcification and resorption.

CLINICAL RELEVANCE

The mental index, mandibular cortical index, and trabecular bone pattern are good parameters for evaluating the effects of RO on severe secondary hyperparathyroidism.

Correlation between hand/wrist and panoramic radiographs in severe secondary hyperparathyroidism

OBJECTIVES

Hand/wrist and dental radiographs are important for osteoporosis analysis in secondary hyperparathyroidism (SHPT). This study evaluated whether a correlation exists between the effects of the disease on the hands and jaws, and investigated the association between osteoporosis progression in the hands and parathyroid hormone (PTH) levels in chronic kidney disease (CKD) patients.

MATERIALS AND METHODS

Four panoramic radiographic parameters (mental index, mandibular cortical index, trabecular bone pattern, and calcification/resorption) and four corresponding hand/wrist radiographic parameters (metacarpal cortical thickness, phalangeal cortical index, trabecular bone pattern, and calcification/resorption) were applied to investigate possible correlation between the effects of SHPT on the jaws and hands/wrists, by Spearman's correlation coefficient. PTH levels and the hand/wrist radiographic parameters were also tested by spearman's correlation coefficient (p < 0.05). The presence of brown tumors, vascular calcifications, and acroosteolysis on the hands was also evaluated.

RESULTS

Mandibular cortical index was strongly correlated with the phalangeal cortical index (p = 0.000). Phalangeal cortical index and trabecular bone pattern of hand/wrist correlated with PTH levels (0.002 and 0.000, respectively). Brown tumors occurred in four CKD patients, while both vascular calcifications and acroosteolysis were observed in 19 patients.

CONCLUSION

There is a significant correlation between the morphological changes caused by secondary hyperparathyroidism in hand and jaw bones. The morphological status can be assessed using the mandibular cortical index, besides the phalangeal cortical index. The latter correlates well with parathyroid hormone levels of advanced chronic kidney disease.

CLINICAL RELEVANCE

Panoramic images reveal morphological changes in the jaw bone, indicating likewise changes in the hand/wrist in severe secondary hyperparathyroidism. The severity of the bone changes may be a reflection of the parathyroid hormone levels in advanced chronic kidney disease.

Changes in fibroblast growth factor 23 during treatment of secondary hyperparathyroidism with alfacalcidol or paricalcitol

BACKGROUND

Fibroblast growth factor 23 (FGF23) increases renal phosphate excretion and decreases the formation of 1,25 dihydroxyvitamin D. In patients with chronic kidney disease, plasma FGF23 levels are markedly elevated by unknown mechanisms. We explored the changes in FGF23 during treatment of secondary hyperparathyroidism (SHPT) with alfacalcidol or paricalcitol in haemodialysis patients.

METHODS

Intravenous alfacalcidol and paricalcitol were compared in haemodialysis patients with SHPT in a randomized 2 × 16-week cross-over study, with 6 weeks washout period preceding treatment and between treatment periods. In 57 of the enrolled patients, blood samples were frozen before and after each treatment period and available for measurement of FGF23.

RESULTS

Treatment with both analogues increased FGF23 (P < 0.05 in all treatment periods). The magnitude of increase was similar for alfacalcidol and paricalcitol (Period 1: 223 versus 314%; P = 0.384 and Period 2: 174 versus 227%; P = 0.510) and the levels returned to pre-treatment levels during the washout period. Independent predictors of rise in FGF23 were baseline levels of FGF23 (P < 0.01), changes in ionized calcium (P < 0.01) and phosphate (P < 0.01) and cumulative dose of vitamin D analogues (P = 0.024).

CONCLUSION

Alfacalcidol and paricalcitol increase the plasma levels of FGF23 equally and substantially in haemodialysis patients.

Optimal vitamin D, calcitriol, and vitamin D analog replacement in chronic kidney disease: to D or not to D: that is the question

PURPOSE OF REVIEW

Patients with chronic kidney disease (CKD) are often insufficient in 25(OH) vitamin D and are almost uniformly deficient in 1,25(OH)2 vitamin D, because of decreased renal hydroxylation resulting from hyperphosphatemia and elevated fibroblast growth factor-23 (FGF-23) levels. These same abnormalities lead to secondary hyperparathyroidism for which the administration of calcitriol or vitamin D analogs has been the mainstay of therapy for decades. This review summarizes new trials of vitamin D, calcitriol, and its analogs over the last 2 years.

RECENT FINDINGS

In addition to the endocrine effects of the vitamin D axis on bone and mineral metabolism, studies have demonstrated there is also extrarenal conversion of 25(OH) vitamin D to 1,25(OH)2 vitamin D in multiple cells leading to autocrine effects. This advance has led to the speculation that CKD patients may also need to be supplemented with ergocalciferol or cholecalciferol. Unfortunately, to date, the majority of interventional studies have focused on biochemical end points. There are no randomized controlled trials demonstrating that therapy with any formulation of vitamin D results in improved patient level outcomes.

SUMMARY

Despite the physiologic importance of vitamin D in health and disease, more research is required to determine which vitamin D derivative is required for optimal health in CKD patients.

No difference between alfacalcidol and paricalcitol in the treatment of secondary hyperparathyroidism in hemodialysis patients: a randomized crossover trial

Alfacalcidol and paricalcitol are vitamin D analogs used for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease, but have known dose-dependent side effects that cause hypercalcemia and hyperphosphatemia. In this investigator-initiated multicenter randomized clinical trial, we originally intended two crossover study periods with a washout interval in 86 chronic hemodialysis patients. These patients received increasing intravenous doses of either alfacalcidol or paricalcitol for 16 weeks, until parathyroid hormone was adequately suppressed or calcium or phosphate levels reached an upper threshold. Unfortunately, due to a period effect, only the initial 16-week intervention period for 80 patients was statistically analyzed. The proportion of patients achieving a 30% decrease in parathyroid hormone levels over the last four weeks of study was statistically indistinguishable between the two groups. Paricalcitol was more efficient at correcting low than high baseline parathyroid hormone levels, whereas alfacalcidol was equally effective at all levels. There were no differences in the incidence of hypercalcemia and hyperphosphatemia. Thus, alfacalcidol and paricalcitol were equally effective in the suppression of secondary hyperparathyroidism in hemodialysis patients while calcium and phosphorus were kept in the desired range.

The association of vitamin D use with hypercalcemia and hyperphosphatemia in hemodialysis patients: a case-crossover study

PURPOSE

Elevated levels of phosphorus (P) and calcium (Ca) have been shown in observational studies to be associated with an increased risk of adverse clinical outcomes including mortality. Vitamin D sterols have been shown to increase the risk of hypercalcemia and hyperphosphatemia in clinical trials. We sought to explore these risks in real-world clinical practice.

METHODS

We employed a case-crossover design, which eliminates confounding by non-time-varying patient characteristics by comparing, within each patient, vitamin D doses before the event with those at an earlier period. Using this method, we estimated the risk of hypercalcemic (Ca ≥ 11 g/dL) and hyperphosphatemic (P ≥ 8 g/dL) events for patients at different dose quartiles of vitamin D relative to patients not on a vitamin D sterol.

RESULTS

There was a dose-dependent association between vitamin D dose quartile and risk of hypercalcemia or hyperphosphatemia. In adjusted analyses, each increase in vitamin D quartile was associated with a multiple of hypercalcemia risk between 1.7 and 19 times compared with those not on vitamin D and a multiple of hyperphosphatemia risk between 1.8 and 4.

CONCLUSION

Use of vitamin D sterols is associated with an increased risk of hypercalcemic and hyperphosphatemic events in real-world clinical practice. Other potential predictors of these events, such as phosphate binder use and dialysate Ca levels, were not examined in this analysis.