Mineral and bone disorder in Chinese dialysis patients: a multicenter study

Prevalence and outcomes associated with hypocalcaemia and hypercalcaemia among pre-dialysis chronic kidney disease patients with mineral and bone disorder

INTRODUCTION

Chronic kidney disease-mineral and bone disease (CKD-MBD) is a complication of chronic kidney disease (CKD) involving derangements in serum calcium and phosphate. This study aims to evaluate hypo- and hypercalcaemia and their associated outcomes among pre-dialysis CKD patients.

METHODS

A retrospective cohort study was performed and included all adult CKD stage 4-stage 5 patients who were on treatment for CKD-MBD between 2016 and 2017. Each patient was followed up for 3 years. Hypo- and hypercalcaemia were defined as serum corrected calcium (Ca 2+ ) <2.10 and >2.46 mmol/L, respectively. Outcomes evaluated included all-cause mortality and cardiovascular events. Multivariate Cox regression analysis was done to evaluate the association of hypocalcaemia and/or hypercalcaemia with the clinical outcomes. Severity of hypocalcaemia episode was classified as 'mild' (Ca 2+ : between 1.90 and 2.10 mmol/L) and 'severe' (Ca 2+ : <1.90 mmol/L). Severity of hypercalcaemia was classified as 'mild' (Ca 2+ : between 2.47 and 3.00 mmol/L), moderate (Ca 2+ : between 3.01 and 3.50 mmol/L) and severe (Ca 2+ : >3.50 mmol/L).

RESULTS

Of the 400 patients, 169 (42.2%) and 94 (23.5%) patients experienced hypocalcaemia and hypercalcaemia, respectively. Severe hypocalcaemia was more prevalent in CKD stage 5 compared to CKD stage 4 (96 [40.5%] vs. 36 [25.9%], P = 0.004). Results from multivariate analyses after adjustment showed that hypocalcaemia and/or hypercalcaemia were not associated with all-cause mortality ( P > 0.05) or the occurrence of cardiovascular events ( P > 0.05).

CONCLUSION

Hypocalcaemia and hypercalcaemia episodes were prevalent among pre-dialysis CKD patients. Studies with longer follow-up durations are required to assess the effects of calcium derangements on clinical outcomes.

Radiofrequency ablation for patients with recurrent or persistent secondary hyperparathyroidism after parathyroidectomy: initial experience

BACKGROUND

Reoperation for recurrent or persistent secondary hyperparathyroidism (SHPT) after parathyroidectomy is challenging due to surgical scars and postoperative adhesions. Therefore, there is an increasing need to develop a new minimally invasive therapy.

OBJECTIVE

To analyze the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) in patients with recurrent or persistent SHPT after parathyroidectomy.

PATIENTS AND METHODS

From March 2013 to January 2022, 20 enlarged parathyroid glands in 10 patients with recurrent or persistent SHPT were treated with US-guided RFA. The levels of serum intact parathyroid hormone (iPTH), calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP), as well as clinical symptoms, were compared before and after RFA. The ablation procedure-related complications were also evaluated. The target range for iPTH levels was approximately 2-9 times the upper limit of normal (130-585 pg/mL).

RESULTS

The mean follow-up time was 49.6 ± 34.5 months (range from 6 to101 months). The levels of serum iPTH, Ca, and P decreased significantly one day post-ablation. Six months after RFA, 70% of patients reached the targets for iPTH, and 50% of patients reached targets at the end of follow-up. Two patients underwent repeat ablation at 9 months and 6 years after RFA, respectively, due to persistently elevated iPTH levels, and both had serum iPTH concentrations in the recommended range at the recent follow-up visit. The patients' clinical symptoms significantly improved after ablation. Major complications after RFA included hoarseness (2/10) and permanent hypoparathyroidism (1/10). Severe hypocalcemia occurred in four patients (4/10) after ablation.

CONCLUSION

US-guided percutaneous RFA for recurrent or persistent SHPT is safe, efficacious, and repeatable, and can significantly improve hyperparathyroidism-related symptoms.

Misdiagnosis of chronic kidney disease and parathyroid hormone testing during the past 16 years

Chronic kidney disease (CKD) is a prevalent pathological condition worldwide. Parathyroid hormone (PTH) is an important index related to bone metabolism in CKD patients and has not received enough attention. This study was performed to investigate the incidence and diagnostic rate of CKDin hospital as well as PTH testing and treatment for secondary hyperparathyroidism (SHPT) in patients with stage 3 to 5 CKD. The data of patients who visited Zhejiang Provincial People's Hospital from February 2006 to April 2022 were retrieved from the hospital database. All data were divided into three subgroups using PTH testing and SHPT treatment as major comparative indicators for analysis. The data were then analyzed for overall PTH testing, CKD incidence, and diagnostic rate. Among 5,301,391 patients, the incidence of CKD was 13.14%. The missed diagnosis rate for CKD was 65.76%. The total PTH testing rate was 1.22%, of which 15.37% of PTH testing was performed in patients with stage 3 to 5 CKD. The overall diagnosis rate of SHPT in patients with stage 3 to 5 CKD was 31.0%. The prophylactic medication rate was 7.4%, and the rate of post-diagnostic drug therapy was 22.2% in patients who underwent SHPT treatment. The high misdiagnosis rate and low PTH testing rate of CKD requires prompt attention from clinicians. SHPT treatment should be considered especially in patients with stage 3 to 5 CKD.

Association of amino acids and parameters of bone metabolism with endothelial dysfunction and vasculopathic changes in limited systemic sclerosis

Objectives

Pathways contributing to endothelial dysfunction in patients with limited cutaneous systemic sclerosis (lcSSc) are largely unknown. The aim of this study was to investigate potential associations of amino acids and parameters of bone metabolism with endothelial dysfunction and vasculopathy-related changes in patients with lcSSc and early-stage vasculopathy.

Methods

Amino acids, calciotropic parameters, including 25-hydroxyvitamin D and parathyroid hormone (PTH), and bone turnover parameters, including osteocalcin and N-terminal peptide of procollagen-3 (P3NP), were measured in 38 lcSSc patients and 38 controls. Endothelial dysfunction was assessed by biochemical parameters, pulse-wave analysis, flow-mediated and nitroglycerine-mediated dilation. Additionally, vasculopathy-related and SSc-specific clinical changes including capillaroscopic, skin, renal, pulmonary, gastrointestinal and periodontal parameters were recorded.

Results

No significant differences in amino acids, calciotropic and bone turnover parameters were observed between lcSSc patients and controls. In patients with lcSSc, several significant correlations were found between selected amino acids, parameters of endothelial dysfunction, vasculopathy-related and SSc-specific clinical changes (all with p < 0.05). In addition, significant correlations were observed between PTH and 25-hydroxyvitamin D with homoarginine, and between osteocalcin, PTH and P3NP with modified Rodnan skin score and selected periodontal parameters (all with p < 0.05). Vitamin D deficiency defined as 25-hydroxyvitamin D < 20 ng/ml was associated with the presence of puffy finger (p = 0.046) and early pattern (p = 0.040).

Conclusion

Selected amino acids may affect endothelial function and may be associated to vasculopathy-related and clinical changes in lcSSc patients, while the association with parameters of bone metabolism seems to be minor.

The Situation and Influencing Factors of Depression and Anxiety in Patients of Hemodialysis during the COVID-19 Pandemic in China

OBJECTIVE

To investigate the incidence of depression and anxiety among maintenance hemodialysis (MHD) patients during the regular prevention and control stage of COVID-19 in China as well as the influencing factors.

METHODS

A cross-sectional study including 180 patients under the treatment of hemodialysis was conducted in the hemodialysis center of the 8th Affiliated Hospital of Sun Yat-Sen University. The questionnaire regarding the subject's general information, Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) was completed by the patients, and the laboratory test results were recorded.

RESULTS

The incidences of anxiety and depression were 35.6% and 38.9%, respectively, and the average scores of SAS and SDS were (48.03 ± 5.02) and (48.12 ± 5.42), respectively, in the subjects. The results showed that age, monthly income, vascular access of dialysis, feeling of pain and itching (within a week), worried about being infected by COVID-19, whether having health insurance and the levels of hemoglobin, parathyroid hormone, and phosphorus were the impact factors of both anxiety and depression in the MHD patients (p < 0.05 for all).

CONCLUSION

The proportion of depression and anxiety is relatively high in the MHD patients during the regular prevention and control stage of COVID-19.

The current status of chronic kidney disease-mineral and bone disorder management in China

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is one of the most common complications of patients with chronic kidney disease (CKD). After considering updated international and domestic CKD-MBD management guidelines, the current management status of CKD-MBD in China remains unclear. We aimed to investigate the management status of CKD-MBD in China. A nationwide survey was combined with a real-world study from Sichuan. Targets recommended in KDIGO 2017 and Chinese 2019 guidelines were used as targets. We compared the data between Sichuan from western China and the eastern developed areas of China, and also compared the results of the real-world data from Sichuan with those of DOPPS5. In the questionnaire, a total of 51,039 maintenance hemodialysis (MHD) patients from 272 centers were involved. Estimated achievement rates for Ca (2.1–2.5 mmol/L), P (1.13–1.78 mmol/L), and iPTH (150–600 pg/mL) levels were 57.1%, 41.1% and 52.0%, respectively. Differences in MBD management between Sichuan from questionnaire and central region. In the real-world survey, a total of 7,053 patients were enrolled. Among them, 57.6%, 24.3%, and 55.0% of patients met corrected Ca, serum P, and iPTH targets specified in Chinese 2019 guidelines, respectively. The comprehensive achievement rate was 7.5%. There are differences in MBD management between Sichuan and DOPPS5 regions, with Sichuan being relatively poorer. The level of the above parameters varies among different genders, age groups, and hospital grades. The achievement rate of serum P was higher in tertiary hospitals and elderly patients (P < 0.05). Current MBD management is poor. Phosphate levels in patients treated in secondary and lower hospitals and young dialysis patients should be strengthened.

Implementation and effectiveness of an intensive education program on phosphate control among hemodialysis patients: a non-randomized, single-arm, single-center trial

BACKGROUND

Hyperphosphatemia is a common complication in patients on maintenance hemodialysis. Patients' adherence to phosphorus control can be improved by consistent education. However, few studies have focused on the model construction and effects of health education on phosphate control for hemodialysis patients.

OBJECTIVE

To develop an intensive education program focusing on phosphate control among hemodialysis patients and to analyze the effectiveness of this program.

DESIGN

A non-randomized, single-arm, single-center trial lasting for 6 months.

SETTING

This program was conducted in a hemodialysis center in a teaching hospital in Zhuhai, China.

PARTICIPANTS

Patients on maintenance hemodialysis with hyperphosphatemia.

METHODS

An intensive hyperphosphatemia control education program lasting for 6 months was conducted among 366 hemodialysis patients applying the First Principles of Instruction model, which focused on mastering four stages: (a) activation of prior experience, (b) demonstration of skills, (c) application of skills and (d) integration of these skills into real-world activities. The controlled percentage of serum phosphorus, knowledge of hyperphosphatemia, and adherence to phosphate binders before and after the education program were assessed.

RESULTS

The proportion of controlled serum phosphorus was significantly increased from 43.5 to 54.9% (P<0.001). The scores on the knowledge of phosphate control were improved significantly from 59.0 ± 18.9 to 80.6 ± 12.4 (P < 0.001). The proportion of high adherence to phosphate binders was increased dramatically from 21.9 to 44.5% (P < 0.001).

CONCLUSION

The intensive education program can effectively improve serum phosphorus, knowledge of hyperphosphatemia, and adherence to phosphate binders among hemodialysis patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100042017 . Retrospectively registered January 12th, 2021.

High prevalence of biochemical disturbances of chronic kidney disease - mineral and bone disorders (CKD-MBD) in a nation-wide peritoneal dialysis cohort: are guideline goals too hard to achieve?

INTRODUCTION

Chronic kidney disease - mineral and bone disorders (CKD-MBD) are common in dialysis patients. Definition of targets for calcium (Ca), phosphorus (P), parathormone (iPTH), and alkaline phosphatase (ALP) and their treatment recommendations, are provided by international guidelines. There are few studies analyzing CKD-MBD in peritoneal dialysis (PD) patients and the impact of guidelines on mineral metabolism control. The aim of our study was to describe the prevalence of biomarkers for CKD-MBD in a large cohort of PD patients in Brazil.

METHODS

Data from the nation-wide prospective observational cohort BRAZPD II was used. Incident patients were followed between December 2004 and January 2011. According to KDOQI recommendations, reference ranges for total Ca were 8.4 to 9.5 mg/dL, for P, 3.5 to 5.5 mg/dL, for iPTH, 150-300 pg/mL, and for ALP, 120 U/L.

RESULTS

Mean age was 59.8 ± 16 years, 48% were male, and 43% had diabetes. In the beginning, Ca was 8.9 ± 0.9 mg/dL, and 48.3% were on the KODQI target. After 1 year, Ca increased to 9.1 ± 0.9 mg/dL and 50.4% were in the KDOQI preferred range. P at baseline was 5.2 ± 1.6 mg/dL, with 52.8% on target, declining to 4.9 ± 1.5 mg/dL after one year, when 54.7% were on target. Median iPTH at baseline was 238 (P25% 110 - P75% 426 pg/mL) and it remained stable throughout the first year; patients within target ranged from 26 to 28.5%. At the end of the study, 80% was in 3.5 meq/L Ca dialysate concentration, 66.9% of patients was taking any phosphate binder, and 25% was taking activated vitamin D.

CONCLUSIONS

We observed a significant prevalence of biochemical disorders related to CKD-MBD in this dialysis population.

Modification and Validation of the Phosphate Removal Model: A Multicenter Study

BACKGROUND

Our research group has previously reported a noninvasive model that estimates phosphate removal within a 4-h hemodialysis (HD) treatment. The aim of this study was to modify the original model and validate the accuracy of the new model of phosphate removal for HD and hemodiafiltration (HDF) treatment.

METHODS

A total of 109 HD patients from 3 HD centers were enrolled. The actual phosphate removal amount was calculated using the area under the dialysate phosphate concentration time curve. Model modification was executed using second-order multivariable polynomial regression analysis to obtain a new parameter for dialyzer phosphate clearance. Bias, precision, and accuracy were measured in the internal and external validation to determine the performance of the modified model.

RESULTS

Mean age of the enrolled patients was 63 ± 12 years, and 67 (61.5%) were male. Phosphate removal was 19.06 ± 8.12 mmol and 17.38 ± 6.75 mmol in 4-h HD and HDF treatments, respectively, with no significant difference. The modified phosphate removal model was expressed as Tpo4 = 80.3 × C45 - 0.024 × age + 0.07 × weight + β × clearance - 8.14 (β = 6.231 × 10-3 × clearance - 1.886 × 10-5 × clearance2 - 0.467), where C45 was the phosphate concentration in the spent dialysate measured at the 45th minute of HD and clearance was the phosphate clearance of the dialyzer. Internal validation indicated that the new model was superior to the original model with a significantly smaller bias and higher accuracy. External validation showed that R2, bias, and accuracy were not significantly different than those of internal validation.

CONCLUSIONS

A new model was generated to quantify phosphate removal by 4-h HD and HDF with a dialyzer surface area of 1.3-1.8 m2. This modified model would contribute to the evaluation of phosphate balance and individualized therapy of hyperphosphatemia.

Parathyroid Hormone Serum Levels and Mortality among Hemodialysis Patients in the Gulf Cooperation Council Countries: Results from the DOPPS (2012-2018)

BACKGROUND

The prospective Dialysis Outcomes and Practice Patterns Study (DOPPS) has collected data since 2012 in all six Gulf Cooperation Council (GCC) countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates). We report the relationship of PTH with mortality in this largest GCC cohort of patients on hemodialysis studied to date.

METHODS

Data were from randomly selected national samples of hemodialysis facilities in GCC-DOPPS phases 5 and 6 (2012-2018). PTH descriptive findings and case mix-adjusted PTH/mortality Cox regression analyses were based on 1825 and 1422 randomly selected patients on hemodialysis, respectively.

RESULTS

Mean patient age was 55 years (median dialysis vintage, 2.1 years). Median PTH ranged from 259 pg/ml (UAE) to 437 pg/ml (Kuwait), with 22% having PTH <150 pg/ml, 24% with PTH of 150-300 pg/ml, 34% with PTH 301-700 pg/ml, and 20% with PTH >700 pg/ml. Patients with PTH >700 pg/ml were younger; on dialysis longer; less likely to be diabetic; have urine >200 ml/d; be prescribed 3.5 mEq/L dialysate calcium; had higher mean serum creatinine and phosphate levels; lower white blood cell counts; and more likely to be prescribed cinacalcet, phosphate binders, or IV vitamin D. A U-shaped PTH/mortality relationship was observed with more than two- and 1.5-fold higher adjusted HR of death at PTH >700 pg/ml and <300 pg/ml, respectively, compared with PTH of 301-450 pg/ml.

CONCLUSIONS

Secondary hyperparathyroidism is highly prevalent among GCC patients on hemodialysis, with a strong U-shaped PTH/mortality relationship seen at PTH <300 and >450 pg/ml. Future studies are encouraged for further understanding this PTH/mortality pattern in relationship to unique aspects of the GCC hemodialysis population.

Hemodialysis patients with low serum parathyroid hormone levels have a poorer prognosis than those with secondary hyperparathyroidism

BACKGROUND

Low serum parathyroid hormone (PTH) level and secondary hyperparathyroidism (SHPT) are very common in hemodialysis patients. However, the outcomes of patients with low PTH level or SHPT have not been carefully compared. Therefore, in the present study, we compared the outcomes of hemodialysis patients with low PTH level or SHPT.

METHODS

This was a multi-center, prospective, cohort study of 647 patients. The patients were recruited between 1 September 2016 and 1 January 2017 and followed until 31 December 2018. The participants were allocated to a low PTH group [serum intact PTH (iPTH) concentration < 60 pg/ml] and an SHPT group (iPTH ⩾ 600 pg/ml) according to their mean iPTH concentration across the entire observation period, and the outcomes were compared between these groups. The primary outcome was a composite outcome, which comprised all-cause mortality, non-fatal acute myocardial infarction, non-fatal acute stroke, and acute heart failure.

RESULTS

A total of 197 hemodialysis patients were allocated to the two groups: 87 with low PTH level and 110 with SHPT; 450 patients with time-averaged iPTH concentrations of 60-600 pg/ml were excluded. Kaplan-Meier analysis of the composite endpoint revealed a significant difference between participants with low PTH level and those with SHPT (p = 0.002). Cox multiple regression showed that participants with low PTH level had a higher incidence of the composite endpoint than those with SHPT (relative risk: 1.337, 95% confidence interval: 1.059-1.688).

CONCLUSION

Hemodialysis patients with low PTH level had a higher incidence of mortality and non-fatal cardiovascular events than those with SHPT, irrespective of whether the participants were age-matched.

Parathyroid Hormone Serum Levels and Mortality among Hemodialysis Patients in the Gulf Cooperation Council Countries: Results from the DOPPS (2012–2018)

Background

The prospective Dialysis Outcomes and Practice Patterns Study (DOPPS) has collected data since 2012 in all six Gulf Cooperation Council (GCC) countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates). We report the relationship of PTH with mortality in this largest GCC cohort of patients on hemodialysis studied to date.

Methods

Data were from randomly selected national samples of hemodialysis facilities in GCC-DOPPS phases 5 and 6 (2012–2018). PTH descriptive findings and case mix–adjusted PTH/mortality Cox regression analyses were based on 1825 and 1422 randomly selected patients on hemodialysis, respectively.

Results

Mean patient age was 55 years (median dialysis vintage, 2.1 years). Median PTH ranged from 259 pg/ml (UAE) to 437 pg/ml (Kuwait), with 22% having PTH <150 pg/ml, 24% with PTH of 150–300 pg/ml, 34% with PTH 301–700 pg/ml, and 20% with PTH >700 pg/ml. Patients with PTH >700 pg/ml were younger; on dialysis longer; less likely to be diabetic; have urine >200 ml/d; be prescribed 3.5 mEq/L dialysate calcium; had higher mean serum creatinine and phosphate levels; lower white blood cell counts; and more likely to be prescribed cinacalcet, phosphate binders, or IV vitamin D. A U-shaped PTH/mortality relationship was observed with more than two- and 1.5-fold higher adjusted HR of death at PTH >700 pg/ml and <300 pg/ml, respectively, compared with PTH of 301–450 pg/ml.

Conclusions

Secondary hyperparathyroidism is highly prevalent among GCC patients on hemodialysis, with a strong U-shaped PTH/mortality relationship seen at PTH <300 and >450 pg/ml. Future studies are encouraged for further understanding this PTH/mortality pattern in relationship to unique aspects of the GCC hemodialysis population.

Pattern of Laboratory Parameters and Management of Secondary Hyperparathyroidism in Countries of Europe, Asia, the Middle East, and North America

INTRODUCTION

This analysis explored laboratory mineral and bone disorder parameters and management of secondary hyperparathyroidism in patients undergoing hemodialysis in Belgium, Canada, China, France, Germany, Italy, Japan, Russia, Saudi Arabia, Spain, Sweden, the UK, and the USA.

METHODS

Analyses used demographic, medication, and laboratory data collected in the prospective Dialysis Outcomes and Practice Patterns Study (2012-2015). The analysis included 20,612 patients in 543 facilities. Descriptive data are presented as regional mean (standard deviation), median (interquartile range), or prevalence, weighted for facility sampling fraction. No testing of statistical hypotheses was conducted.

RESULTS

The frequency of serum intact parathyroid hormone levels > 600 pg/mL was lowest in Japan (1%) and highest in Russia (30%) and Saudi Arabia (27%). The frequency of serum phosphorus levels > 7.0 mg/dL was lowest in France (4%), the UK (6%), and Spain (6%), and highest in China (27%). The frequency of serum calcium levels > 10.0 mg/dL was highest in the UK (14%) and China (13%) versus 2% to 9% elsewhere. Dialysate calcium concentrations of 2.5 mEq/mL were common in the USA (78%) and Canada (71%); concentrations of 3.0-3.5 mEq/L were almost universal at facilities in Italy, France, and Saudi Arabia (each ≥ 99%).

CONCLUSIONS

Wide international variation in mineral and bone disorder laboratory parameters and management practices related to secondary hyperparathyroidism suggests opportunities for optimizing care.

The history of hemodialysis in China

The technique of hemodialysis was introduced into China more than 50 years ago; and both research and use of clinical hemodialysis began in mid-1960s to late-1960s. A brief review of the history of hemodialysis in China is presented here, including a brief description of pioneers and their contributions, local development and use of dialyzers, hemodialysis machines, and vascular access, and dialysis management and logistics.

Mineral and bone disorder and management in the China Dialysis Outcomes and Practice Patterns Study

BACKGROUND

Despite a growing population of patients starting hemodialysis in China, little is known about markers of mineral bone disease (MBD) and their management. We present data on prevalence and correlates of hypocalcemia, hyperphosphatemia, and secondary hyperparathyroidism from the China Dialysis Outcomes and Practice Patterns Study (DOPPS), with evaluation of whether these laboratory markers triggered changes in management.

METHODS

We compared the frequency of measurement and prevalence of poor control of MBD markers in China DOPPS with other DOPPS regions. We also used generalized estimating equations to assess correlates of MBD markers, and separate models to assess predictors of vitamin D and phosphate binder prescriptions in the China DOPPS.

RESULTS

Severe hyperphosphatemia (>7 mg/dL) and secondary hyperparathyroidism (>600 pg/mL) were common (27% and 21% prevalence, respectively); both were measured infrequently (14.9% and 3.2% of patients received monthly measurements in China). Frequency of dialysis sessions was positively associated with hyperphosphatemia; presence of residual kidney function was negatively associated with both hyperphosphatemia and secondary hyperparathyroidism. Laboratory measures indicating poor control of MBD were not associated with subsequent prescription of active vitamin D or phosphate binder.

CONCLUSIONS

There are substantial opportunities for improvement and standardization of MBD management in China. Development of country-specific guidelines may yield realistic targets and standardization of medication use accounting for availability and cost.

Mineral and bone disorder in hemodialysis patients in the Tibetan Plateau: a multicenter cross-sectional study

Background: Mineral and bone disorder (MBD) in hemodialysis patients is associated with increased morbidity and mortality. Studies on the MBD status of hemodialysis patients at high altitudes are extremely limited. Methods: A total of 146 hemodialysis patients from 5 local hospitals across all districts with hemodialysis centers in the Tibetan Plateau were enrolled in this cross-sectional study. Parameters related to MBD, including serum phosphorus (P), calcium (Ca), and intact parathyroid hormone (iPTH) levels, were measured. The achievement of MBD goals was compared with the achievement in the Dialysis Outcomes and Practice Study (DOPPS) 3, DOPPS 4 and a multicenter study of MBD in China. Factors associated with hyperphosphatemia were examined. Results: Altogether, 146 hemodialysis patients were recruited from the Tibetan Plateau. According to the K/DIGO guidelines, there were low achievement rates for serum Ca (40.4%), P (29.7%), and iPTH (47.1%). As for the (KDOQI) guidelines, the rates of achievement of defined targets were 38.4%, 33.7% and 16.4% for serum Ca, P and iPTH, respectively. The percentages of patients reaching the KDOQI targets for corrected Ca, P, and iPTH were significantly lower for Tibetan patients than the percentages found in DOPPS 3 (38.4% vs. 50.4%, 33.7% vs. 49.8%, and 16.4% vs. 31.4%, respectively, all p < .001) and DOPPS 4 (38.4% vs. 56.0%, 33.7% vs. 54.5%, and 16.4% vs. 35.3%, respectively, all p < .001). The percentage of patients reaching the KDOQI targets for iPTH was significantly lower in Tibet than in the plain areas of China (16.4% vs. 26.5%, p < .001). The proportion of patients with hypocalcemia was higher in Tibet than in the plain areas (44.5% vs. 19.4%, p < .001). The percentage of local patients with optimal P was significantly higher for patients with an activated vitamin D prescription than for patients without an activated vitamin D prescription (45.3% vs. 19.3%, p < .001). Age and the activated vitamin D prescription were independently associated with hyperphosphatemia. Conclusion: The MBD status of hemodialysis patients in Tibet is far from the ideal level. High altitude is one of the possible causes of the differences found, but not the principal one. It is necessary for medical staff in Tibet to improve the detection and treatment of MBD.

Associations between serum mineral metabolism parameters and mortality in patients on peritoneal dialysis

AIM

Disturbances in mineral metabolism markers are common in patients with chronic kidney disease but there is no consensus on the association between these markers and clinical outcomes. This study investigated associations between mineral metabolism parameters and mortality in Chinese peritoneal dialysis (PD) patients.

METHODS

This was a single-centre retrospective cohort study. Incident PD patients between 1 January 2006 and 31 December 2013 with baseline phosphate, albumin-corrected calcium, and calcium-phosphate product data were enrolled. Associations between these parameters and all-cause and cardiovascular mortality were assessed using multivariable-adjusted Cox models.

RESULTS

Of 1662 patients (mean age: 47.4 ± 15.3 years), 59.3% were male and 23.8% had diabetes. Over a median 38.1 month (interquartile range: 21.3-59.7 months) follow-up period, 382 (23.0%) patients died. After adjusting for confounders, the higher serum phosphate level (>1.78 mmol/L) and calcium-phosphate product level (≥4.4 mmol² /L² ) were significantly associated with an increased risk for all-cause mortality (hazards ratio (HR) = 1.818, 95% CI = 1.379-2.396 and HR = 1.735, 95% CI = 1.261-2.386) and cardiovascular mortality (HR = 2.069, 95% CI = 1.428-2.998 and HR = 2.175, 95% CI = 1.450-3.262), respectively. While each 1 mmol/L higher baseline albumin-corrected calcium level was associated with an 14.3% (95% CI = 0.749-0.981) lower risk for all-cause mortality after adjusting for potential confounders.

CONCLUSION

Abnormalities in mineral metabolism markers, particularly higher serum phosphate and calcium-phosphate product levels, at the commencement of PD were independently associated with increased all-cause and cardiovascular mortality in this cohort of PD patients.

The association between periodontal conditions, inflammation, nutritional status and calcium-phosphate metabolism disorders in hemodialysis patients

Objectives

To analyze the association between periodontal conditions and inflammation, nutritional status and calcium-phosphate metabolism disorders in hemodialysis (HD) patients.

Material and Methods

We analyzed 128 HD patients divided into two groups: dentate (n = 103) and edentulous (n=25). The following items were assessed: baseline characteristics, age at the start and duration of HD, biochemical data: C-reactive protein (CRP), serum albumin, calcium, phosphorus, alkaline phosphatase, parathormone. A single dentist performed a complete dental/periodontal examination, including parameters of oral hygiene and gingival bleeding.

Results

One person had healthy periodontium, 62.14% of the patients had gingivitis, and 36.9% had moderate or severe periodontitis. The age at HD onset had a positive impact on periodontal status and negatively correlated with the number of teeth. A positive correlation between age and CRP level and negative correlations between age and serum albumin and phosphorus were found. Pocket depth (PD) was negatively correlated with serum albumin. The number of teeth was negatively correlated with serum CRP.

Conclusions

High prevalence and severity of periodontal disease are observed in hemodialysis patients. There is a high probability that periodontal disease may be present at the early stages of chronic kidney disease (CKD) before the hemodialysis onset.

Microwave ablation: an effective treatment for mild-to-moderate secondary hyperparathyroidism in patients undergoing haemodialysis

BACKGROUND

Microwave ablation (MWA) is an effective treatment for severe secondary hyperparathyroidism (SHPT), but it can also be used for mild-to-moderate secondary hyperparathyroidism (SHPT). In this randomised, controlled study, the efficacy of MWA in the treatment of mild-to-moderate hyperparathyroidism is investigated.

MATERIALS AND METHODS

We assessed outcomes 12 months after the randomisation of 28 patients with mild-to-moderate SHPT. The subjects received either MWA plus calcitriol or calcitriol alone. The primary end-points were the rate of achieving target levels of intact parathyroid hormone (iPTH), changes in iPTH levels and the rate of patients developing severe SHPT.

RESULTS

Primary end points: the overall rates of achieving target levels of iPTH were comparable between the MWA and calcitriol alone groups (24% vs. 22%, p = 0.85). However, the rate of iPTH <150 pg/mL (lower limit of the target range) in the MWA group was higher than that in the calcitriol alone group (23% vs. 8%, p = 0.02). The mean iPTH level in the MWA group after MWA was lower than that in the calcitriol alone group (373.09 ± 322.31 vs. 552.28 ± 361.87 pg/mL, p < 0.001). There was a significant difference in the change in iPTH levels over time within the MWA group (p < 0.001) but not in the calcitriol alone group. Only one patient developed severe SHPT in the MWA group, while six patients in the calcitriol alone group developed severe SHPT (p = 0.04).

CONCLUSIONS

Compared with calcitriol alone, MWA plus calcitriol decreases iPTH levels and prevents the progression of mild-to-moderate SHPT.

Chronic Kidney Disease-Mineral and Bone Disorder in Asia

BACKGROUND

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is one of the most common complications in patients with CKD. As CKD-MBD is a systemic syndrome, prevention and management should be aimed at achieving better survival and less risk of cardiovascular events and fractures.

SUMMARY

Although target ranges for serum markers of mineral metabolism have been proposed in several global or local guidelines, these were mostly based on data from non-Asian patients. Additionally, there remain differences in medical and social systems as well as in economic status, even among Asian countries and areas.

KEY MESSAGE

Asian CKD patient data needs to be analyzed, published, and shared to establish optimal local strategies for CKD-MBD management.

Clinical Epidemiology of Mineral Bone Disorder Markers in Prevalent Hemodialysis Patients in the Xinjiang Uyghur Autonomous Region in China

We investigated the clinical epidemiology of mineral bone disorder markers in prevalent hemodialysis (HD) patients in Xinjiang, the largest province in China. Data were obtained from 59 hospitals. A total of 3725 patients tracked from January 1 to December 31, 2014, were enrolled. Serum calcium (Ca) levels, phosphorus (P) levels, and intact parathyroid hormone (iPTH) levels were analyzed. Serum Ca levels were lower compared to the International Dialysis Outcomes and Practice Patterns Study (DOPPS4) and the Chinese DOPPS. The hypercalcemia rate was similar to DOPPS4 and lower than in the Chinese DOPPS. Serum P levels were higher than in DOPPS4 and lower than those in the Chinese DOPPS. Hyperphosphatemia rates were higher than DOPPS4 and lower than Chinese DOPPS. Serum iPTH levels were higher than in DOPPS4 and the Chinese DOPPS. We demonstrated higher serum P and iPTH levels in Xinjiang HD patients than in the DOPPS4 and Chinese DOPPS. In contrast, serum Ca levels were lower than the other two studies. High hypocalcemia and hyperphosphatemia rates may suggest that HD services in Xinjiang are inadequate. A multidiscipline chronic kidney disease (CKD) care program needs to be established to improve chronic kidney disease-mineral and bone disorder (CKD-MBD) target achievement in Xinjiang.

Association between the Achievement of Target Range CKD-MBD Markers and Mortality in Prevalent Hemodialysis Patients in Taiwan by Using the Kidney Disease: Improving Global Outcomes Clinical Guidelines

Background. This study evaluated the association between achieving target chronic kidney disease-mineral and bone disorder (CKD-MBD) marker levels and mortality in Taiwanese hemodialysis (HD) patients. Target levels were based on the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Methods. We performed a retrospective medical record review of 1126 HD patients between 2009 and 2013. A logistic regression model was used to evaluate the relationship between achieving target marker levels and the risk for all-cause and cardiovascular (CV) mortality. Reference target ranges were 7.9 ≤ calcium (Ca) ≤ 9.9 mg/dL, 2.4 ≤ phosphate (P) ≤ 4.7 mg/dL, and 144 ≤ intact parathyroid hormone (iPTH) ≤ 648 pg/mL. Results. Achievement of target P levels was associated with a lower risk for all-cause mortality compared to achievement of either target Ca or iPTH levels. Achieving target P + iPTH levels (OR 1.32) was associated with a lower odds ratio for all-cause mortality compared to achieving target Ca + P (OR 1.66) and Ca + iPTH (OR 1.43) levels. Similar trends were observed for CV mortality risk. Conclusions. The present study demonstrated that achieving serum P levels within the KDIGO target range is the most important factor for lowering mortality in HD patients.

Impact of Dialysate Calcium Concentration on Clinical Outcomes in Incident Hemodialysis Patients

The association between dialysate calcium (DCa) concentration and mortality in hemodialysis (HD) patients is controversial. In this study, we evaluated the impact of DCa concentration on mortality in incident HD patient. Incident HD patients were selected from the Clinical Research Center registry-a prospective cohort study on dialysis patients in Korea. Patients were categorized into 3 groups according to the prescribed DCa concentration at the time of enrollment. High DCa was defined as a concentration of 3.5 mEq/L, mid-DCa as 3.0 mEq/L, and low DCa as 2.5 to 2.6 mEq/L. The primary outcome was all-cause mortality and secondary outcomes were cardiovascular or infection-related hospitalization. A total of 1182 patients with incident HD were included. The number of patients in each group was 182 (15.4%) in high DCa group, 701 (59.3%) in the mid-DCa group, and 299 (25.3%) in the low DCa group. The median follow-up period was 16 months. The high DCa group had a significantly higher risk of all-cause mortality compared with the mid-DCa group (hazard ratio [HR] 2.23, 95% confidence interval [CI] 1.28-3.90, P = 0.005) and the low DCa group (HR 3.67, 95% CI 1.78-7.55, P < 0.001) after adjustment for clinical variables. The high DCa group was associated with higher risk of cardiovascular and infection-related hospitalization compared with the low DCa group (HR 3.25, 95% CI 1.53-6.89, P = 0.002; and HR 2.77, 95% CI 1.29-5.94, P =  .009, respectively). Of these 1182 patients, 163 patients from each group were matched by propensity scores. In the propensity score matched analysis, the high DCa group had a significantly higher risk of all-cause mortality compared with the mid-DCa group (HR 2.52, 95% CI 1.04-6.07, P = 0.04) and the low DCa group (HR 4.25, 95% CI 1.64-11.03, P = 0.003) after adjustment for clinical variables. Our data showed that HD using a high DCa was a significant risk factor for all-cause mortality and cardiovascular or infection-related hospitalization in incident HD patients.

Improving diet recipe and cooking methods attenuates hyperphosphatemia in patients undergoing peritoneal dialysis

BACKGROUND AND AIMS

Hyperphosphatemia is an independent predictor for cardiovascular and all-cause mortality in patients undergoing peritoneal dialysis (PD). The study aimed to investigate the effect of dietary intervention on reducing serum phosphate concentration in hyperphosphatemic PD patients.

METHODS AND RESULTS

In this single-center clinical trial, 97 prevalent PD patients with serum phosphate concentration ≥ 1.6 mmol/l were allocated to the intervention (n = 48) or control (n = 49) group and followed up for 1 year. In addition to phosphate binder (calcium carbonate) therapy, patients in the intervention group were intensively educated to reduce phosphate-rich food intake and improve cooking methods. While stable in the control group (1.97 ± 0.20 to 1.94 ± 0.35 mmol/l, p > 0.05), the serum phosphate concentration decreased significantly in the intervention group (1.98 ± 0.28 to 1.65 ± 0.33 mmol/l, p = 0.015) concurrently with the drop in dietary phosphate intake (13.03 ± 3.39 to 10.82 ± 3.00 mg/kg ideal body weight/day, p = 0.001). Moreover, after 6 months of intervention, fewer patients needed to use calcium carbonate (from 64.6% to 41.5%, p = 0.029) and the medicine dose reduced significantly (from 2.25 (0, 3.94) to 0 (0, 1.50) g/day, p < 0.001).

CONCLUSIONS

Our data indicated that intensive dietary intervention of reducing phosphate-rich food intake and improving cooking methods attenuated hyperphosphatemia in PD patients. It suggests that regular assessment of dietary phosphate intake and modification of diet recipe and cooking methods are essential for hyperphosphatemia treatment in PD patients in addition to phosphate binder therapy.

Effect of individual health education on hyperphosphatemia in the Hakkas residential area

The Hakka are a sub-ethnicity with unique diet customs in South China. This study investigated hyperphosphatemia in hemodialysis patients in relation to the current Hakka dietary customs and explored health education patterns for hyperphosphatemia control. Two continuous cross-sectional surveys were conducted among the local patients on dialysis. After the first survey, the patients with hyperphosphatemia were semi-randomized into regular (group 1) and individual (group 2) education groups. Regular health education was conducted for both groups. In group 2, the awareness of health knowledge and dietary customs was investigated using a self-designed questionnaire. Based on the questionnaire, individual dietary guidance was given. The second survey was performed after 3 months. In the first survey, a high-phosphorus diet was found in all 46 patients with 43 (93.5%) diagnosed with hyperphosphatemia. In group 1 and group 2, 15 patients and 25 patients completed the two surveys, respectively. In group 1, no patient changed their dietary habits; however, in group 2, some patients did. The level of serum inorganic phosphorus in group 1 increased significantly. In group 2, the data remained stable; the awareness rate of chronic kidney disease-mineral and bone disorder (CKD-MBD) increased, and six patients with good compliance showed decreased serum inorganic phosphorus (p = 0.046). High-phosphorus dietary customs and low CKD-MBD knowledge awareness are important reasons for the difficulty in hyperphosphatemia control of patients on dialysis in the Hakka region. Individual health education led by medical staff might be helpful in hyperphosphatemia control, but the pattern still needs further exploration.

Vascular calcification burden of Chinese patients with chronic kidney disease: methodology of a cohort study

Background

Vascular calcification is a common complication associated with chronic kidney disease and the major cause of cardiovascular disease in patients with end-stage renal disease. The vascular calcification risk burden is still unknown in China. This study aims to investigate the prevalence of vascular calcification and assess the predictive value of vascular calcification in patients with stage 5 chronic kidney disease on dialysis in China.

Methods/Design

This is a national, multicenter, non-interventional, prospective cohort study planning to recruit 1520 patients with end-stage renal disease receiving hemodialysis or peritoneal dialysis for at least 6 months in 24 dialysis centers in China. All the patients provided written informed consents before participating in this study. It will include a baseline visit and 24 months follow-up period with 4 other visits at 6-month intervals. Vascular calcification images will be obtained to determine the prevalence of vascular calcification, coronary artery calcification, abdominal aortic calcification and cardiac valve calcification. Association between vascular calcification and all-cause and cardiovascular disease mortality and non-fatal cardiovascular events will be assessed. Disease management, as assessed by serum level of calcium, phosphorus and intact parathyroid hormone and its impact on vascular calcification, will also be surveyed.

Discussion

The new results gained from this study will supplement limited current available data and provide better clinical decisions in Chinese patients with chronic kidney disease on dialysis.

Practical use of sevelamer in chronic kidney disease patients on dialysis in People's Republic of China

Hyperphosphatemia is a common complication of dialysis patients. Only 38.5% of Chinese dialysis patients met the Kidney Disease Outcomes Quality Initiative defined targets for serum phosphate. Sevelamer is a high molecular weight cationic hydrogel polymer that prevents absorption of dietary phosphate by binding it in the gastrointestinal tract. In Chinese trials, it was confirmed that sevelamer had better efficacy than calcium carbonate in terms of reducing the serum level of phosphorus and calcium-phosphate product. Sevelamer can also reduce the levels of lipid parameters and improve the micro-inflammatory state. When sevelamer was combined with other treatments, it elicited superior effects on calcium phosphorus metabolism, secondary hyperparathyroidism, and renal osteodystrophy. Combination treatment of sevelamer and traditional Chinese medicine has the unique advantage. However, sevelamer is associated with a high incidence of gastrointestinal adverse effects in Chinese patients. Although more effective, the practical use of sevelamer is not very common because it is expensive and not paid by medical insurance. This article provides a comprehensive review of the practical use of sevelamer in chronic kidney disease patients on dialysis in People's Republic of China.

Is the dialysate calcium concentration of 1.75 mmol/L suitable for Chinese patients on maintenance hemodialysis?

We studied the effects of increasing the dialysate calcium concentration (DCa) to 1.75 mmol/L on controlling chronic kidney disease-mineral and bone disorder in Chinese patients on maintenance hemodialysis (MHD). We reviewed the data of MHD patients in one center (cohort 1) during prior 10 years and analyzed the risk factors of mortality and transference calcification (TC) in120 MHD patients surviving in 2003 (cohort 2). A multicenter, prospective, parallel-group, controlled trial (cohort 3) was also conducted from January 2011 to December 2012. The DCa at one center was increased from 1.5 to 1.75 mmol/L but was not changed at the other two centers. The clinical outcomes, biochemical parameters, medicine treatments, and TC markers [aortic arch calcification score (AoACS)] were compared between groups. In cohort 1, the annual mean serum iPTH increased significantly over 10 years. In cohort 1, 72 patients survived for 10 years, whose doses of calcium salts and active vitamin D3 and AoACs increased progressively. In cohort 2, the main cause of death was cardiocerebrovascular disease (CCVD) (n = 18, 48.6 %). Male sex and lower serum calcium concentrations were independent risk factors for CCVD mortality. In cohort 3, serum phosphorus, iPTH, and 25(OH)D decreased and serum calcium increased significantly; also, the doses of calcium and vitamin D3 decreased from 2011 to 2012 in the DCa 1.75 group. There were no significant differences in clinical outcomes either between groups or between the two calendar years. Our results indicate that increasing DCa to 1.75 mmol/L can decrease the elevated levels of serum iPTH and phosphorus, reduce the doses of calcium and vitamin D3, and be safe for short periods of time.

Alkaline phosphatase and mortality in patients on peritoneal dialysis

BACKGROUND AND OBJECTIVES

Elevated total serum alkaline phosphatase levels have been associated with higher mortality in the general population, CKD patients, and hemodialysis patients. However, in peritoneal dialysis patients, this association has received little attention. The aim of this study was to evaluate the association between alkaline phosphatase and all-cause and cardiovascular mortality in peritoneal dialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this single center retrospective cohort study, 1021 incident peritoneal dialysis patients from January 1, 2006, to December 31, 2010 with baseline serum alkaline phosphatase values were enrolled. Collected baseline data included demographic characteristics and clinical and laboratory measurements. All patients were followed until December 31, 2012. The associations of total serum alkaline phosphatase levels with all-cause and cardiovascular mortality were assessed using multivariable-adjusted Cox models.

RESULTS

Of 1021 patients, mean age was 47.5 (± 15.5) years, 59.1% of patients were men, and 22.8% of patients were diabetic. The median serum alkaline phosphatase level was 64 U/L (interquartile range=52-82 U/L). During a median 31-month (interquartile range=19-45 months) follow-up period, 203 patients died, of which 109 deaths were caused by cardiovascular disease. After adjusting for demographics, comorbid conditions, liver function, and bone metabolism parameters, the highest alkaline phosphatase quartile was significantly associated with a hazard ratio for all-cause mortality of 1.70 (95% confidence interval, 1.06 to 2.74, P=0.03) and a hazard ratio for cardiovascular mortality of 1.94 (95% confidence interval, 1.02 to 3.72, P=0.04). Each 10 U/L higher baseline alkaline phosphatase level was associated with 4% (95% confidence interval, 1.00 to 1.08, P=0.04) and 7% (95% confidence interval, 1.02 to 1.11, P=0.003) higher risk of all-cause and cardiovascular mortality, respectively.

CONCLUSION

Higher total serum alkaline phosphatase levels at the commencement of peritoneal dialysis were independently associated with all-cause and cardiovascular mortality in peritoneal dialysis patients.