KDOQI US commentary on the 2009 KDIGO Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of CKD-Mineral and Bone Disorder (CKD-MBD)

Long-term safety of total knee arthroplasty in patients with chronic kidney disease in Taiwan: A retrospective cohort study

BACKGROUND

Chronic kidney disease (CKD) is a prevalent condition in Taiwan, and the incidence of total knee arthroplasty (TKA) is on the rise. This study aimed to evaluate the postoperative results of patients with different degrees of CKD after TKA, using data from the Taiwan National Health Insurance Research Database.

METHODS

The study analyzed 3078 patients who received TKA from 2012 to 2017, equally divided into three groups: none-CKD, mild CKD (without dialysis), and severe CKD (with dialysis). Propensity score matching was used to minimize selection bias.

RESULTS

After TKA, there was no significant difference in the risk of debridement surgery for infection between the three groups (adjusted HR of mild CKD: 0.71 95% CI=0.36-1.38, p=0.3073; adjusted HR of severe CKD: 1.14, 95% CI=0.63-2.06, p=0.6616). However, CKD patients requiring dialysis had a significantly higher risk of mortality (adjusted HR: 1.98, 95% CI=1.57-2.50, p<0.001) and readmission within 90days of any causes (adjusted HR: 1.83, 95% CI=1.48-2.26, p<0.001) than non-CKD and mild CKD patients.

CONCLUSION

Severe CKD patients needing dialysis after TKA have a higher risk of mortality and readmission rates than that of the non-CKD or mild CKD patients. If the patient is in the early stage of CKD, their prognosis after receiving TKA is expected to be as good as non-CKD patients.

LEVEL OF EVIDENCE

IV; well-designed cohort study.

Association of serum intact parathyroid hormone levels with sarcopenia in patients undergoing peritoneal dialysis

Objective

Sarcopenia is highly prevalent in patients undergoing peritoneal dialysis (PD), contributing to adverse clinical outcomes. Animal models suggest that parathyroid hormone (PTH) induces muscle wasting through adipose tissue browning. However, the relationship between PTH dysregulation and sarcopenia in the PD population remains unclear. Thus, we aimed to explore the association between serum intact PTH levels and sarcopenia in PD patients.

Methods

We conducted a cross-sectional analysis using data from the Tzu-Chi PD cohort, comprising 186 PD patients with a mean age of 57.5 ± 14.1 years. Basic information, comorbidities, serum intact PTH levels, and other biochemical data were retrieved. Atherosclerotic cardiovascular disease (ASCVD) includes any history of coronary artery disease, myocardial infarction, peripheral arterial disease, and stroke. All patients were evaluated for appendicular skeletal muscle mass (ASM) using the Body Composition Monitor (BCM), handgrip strength, and 6-m usual gait speed. Sarcopenia was defined based on the consensus of the Asian Working Group for Sarcopenia 2019. Relative over-hydration (OH) was also assessed using BCM.

Results

The overall prevalence of sarcopenia was 38.2%. Across three groups of intact PTH levels (<150 pg/mL, 150-300 pg/mL, and >300 pg/mL), the prevalence rates of sarcopenia were 29.7, 36.4, and 46.2%, respectively (p for trend = 0.044). In the unadjusted model, age, ASCVD, subjective global assessment score, body mass index, relative OH, serum albumin, creatinine, phosphorus, and log-transformed intact PTH levels were significantly associated with sarcopenia. After full adjustment for all above factors, age (odds ratio [OR] = 1.04, 95% confidence interval [CI] = 1.00-1.08), ASCVD (OR = 4.12, 95% CI = 1.34-12.65), BMI (OR = 0.51, 95% CI = 0.41-0.64), relative OH (OR = 1.04, 95% CI = 1.00-1.07), log-transformed intact PTH levels (OR = 3.72, 95% CI = 1.51-9.14) were independently associated sarcopenia among PD patients.

Conclusion

Among PD patients, elevated serum intact PTH levels are independently associated with sarcopenia. Further longitudinal studies are warranted to confirm their causal relationship.

Tc-99m-MIBI SPECT/CT imaging to diagnose secondary hyperparathyroidism after parathyroid forearm transplantation

This article report a 40-year-old male patient who underwent total thyroidectomy and forearm auto-transplantation in another hospital for secondary hyperparathyroidism. After 4 years of follow-up, the level of parathyroid hormone continued to increase, and ultrasound showed nodules in the neck and right forearm, which were considered to be of parathyroid origin. Technetium 99m sestamibi single photon emission computed tomography and computed tomography (Tc-99m-MIBI SPECT/CT) imaging showed increased radioactive uptake in the submuscular soft tissue nodule of the right medial forearm, maximum standardized uptake value (SUVmax) is 0.98, which was identified as transplanted functioning parathyroid tissue. No parathyroid imaging activity was found in the neck. The patient then underwent partial removal of ectopic parathyroid tissue from the right forearm. Pathological examination confirmed parathyroid tissue, and removal was followed by a rapid decline in serum parathyroid hormone levels.

Pharmaceutical Management of Secondary Hyperparathyroidism and the Role of Surgery: A 5-Year Retrospective Study

Background and Objectives: Secondary hyperparathyroidism (SHPT) poses a common condition among patients with chronic kidney disease (CKD) due to the chronic stimulation of the parathyroid glands as a result of persistently low calcium levels. As a first option for medical treatment, vitamin D receptor analogs (VDRAs) and calcimimetic agents are generally used. Apart from cinacalcet, which is orally taken, in recent years, another calcimimetic agent, etelcalcetide, is being administered intravenously during dialysis. Materials and Methods: In a 5-year retrospective study between 2018 and 2023, 52 patients undergoing dialysis were studied. The aim of this study is to highlight the possible effects and/or benefits that intravenously administered calcimimetic agents have on CKD patients. A total of 34 patients (65.4%) received cinacalcet and etelcalcetide while parathormone (PTH) and calcium serum levels were monitored on a monthly basis. Results: A total of 29 out of 33 patients (87.9%) that received treatment with etelcalcetide showed a significant decrease in PTH levels, which rose up to 57% compared to the initial values. None of the included patients needed to undergo parathyroidectomy (PTx) due to either extremely high and persistent PTH levels or severe side effects of the medications. It is generally strongly advised that parathyroidectomies should be performed by an expert surgical team. In recent years, a significant decrease in parathyroidectomies has been recorded globally, a fact that is mainly linked to the constantly wider use of new calcimimetic agents. This decrease in parathyroidectomies has resulted in an important decrease in complications occurring in cervical surgeries (e.g., perioperative hemorrhage and nerve damage). Conslusions: Despite the fact that these surgical complications cannot be easily compared to the pharmaceutical side effects, the recorded decrease in parathyroidectomies is considered to be notable, especially in cases of relapse where a difficult reoperation would be considered based on previously published guidelines.

Academy of Nutrition and Dietetics Commentary on the Phosphorus Recommendation in the KDOQI Clinical Practice Guidelines for Nutrition in CKD: 2020 Update

The Kidney Disease Outcomes Quality Initiative Clinical Practice Guidelines for Nutrition in Chronic Kidney Disease: 2020 Update recommends adjusting dietary phosphorus to maintain a serum phosphate goal for hemodialysis patients in the normal range (0.81 to 1.45 mmol/L [2.5 to 4.5 mg/dL]). This is lower than the serum phosphate goal used by many dialysis centers (0.97 to 1.78 mmol/L [3.0 and 5.5 mg/dL]). Although context and clinical judgment must always be considered when providing individualized care to patients, a guideline implementation study conducted from December 2020 to December 2022 found that, based on their documentation, registered dietitian nutritionists from two national dialysis chains are almost universally using dialysis center goals instead of the lower phosphate goal recommended by the guideline. This commentary discusses the possible barriers to implementing the Kidney Disease Outcomes Quality Initiative 2020 nutrition guideline's phosphorus recommendation and proposes a systems level approach to promote and support adoption of the recommendation. Calls to action for potential changes in clinician practices, organizational/institutional culture, and government regulations are put forth.

Renal hyperparathyroidism- a risk factor in the development of encapsulating peritoneal sclerosis

Background

Encapsulating peritoneal sclerosis (EPS) is a rare complication of prolonged peritoneal dialysis (PD) exposure, characterised by peritoneal thickening, calcification, and fibrosis ultimately presenting with life-threatening bowel obstruction. The presence or role of peritoneal calcification in the pathogenesis of EPS is poorly characterised. We hypothesise that significantly aberrant bone mineral metabolism in patients on PD can cause peritoneal calcification which may trigger the development of EPS. We compared the temporal evolution of bone mineral markers during PD in EPS patients with non-EPS long-term PD controls.

Methods

Linear mixed model and logistic regression analysis were used to compare four-monthly serum levels of calcium, phosphate, parathyroid hormone, and alkaline phosphatase (ALP) over the duration of PD exposure in 46 EPS and 46 controls (PD, non-EPS) patients.

Results

EPS patients had higher mean calcium (2.51 vs. 2.41 mmol/L) and ALP (248.00 vs. 111.13 IU/L) levels compared with controls (p=0.01 and p<0.001 respectively, maximum likelihood estimation). Logistic regression analysis demonstrated that high serum calcium and phosphate levels during PD were associated with a 4.5 and 2.9 fold increase in the risk of developing EPS respectively.

Conclusion

High levels of calcium and phosphate in patients on PD were identified to be risk factors for EPS development. Possible reasons for this may be an imbalance of pro-calcifying factors and calcification inhibitors promoting peritoneal calcification which increases peritoneal stiffness. Mechanical alterations may trigger, unregulated fibrosis and subsequent development of EPS. Improved management of secondary hyperparathyroidism during PD may ultimately diminish the EPS risk.

Advantages of total parathyroidectomy in patients with secondary hyperparathyroidism induced by end stage renal disease

Introduction

Secondary hyperparathyroidism, as a result of chronic kidney disease could be treated medically or surgically. When pharmacotherapy fails, patients undergo surgery - parathyroidectomy, the curative treatment of secondary hyperparathyroidism (SHPT). There are currently 3 accepted surgical techniques, each with supporters or opponents - total parathyroidectomy, subtotal parathyroidectomy and parathyroidectomy with immediate autotransplantation.

Methods

In this paper we described our experience on a series of 160 consecutive patients diagnosed with secondary hyperparathyroidism who underwent surgery, in 27 cases it was totalization of the intervention (patients with previously performed subtotal parathyroidectomy or with supernumerary glands and SHPT recurrence). We routinely perform total parathyroidectomy, the method that we believe offers the best results.

Results

The group of patients was studied according to demographic criteria, paraclinical balance, clinical symptomatology, pre- and postoperative iPTH (intact parathormone) values, SHPT recurrence, number of reinterventions. In 31 cases we found gland ectopy and in 15 cases we discovered supernumerary parathyroids. A percentage of 96.24% of patients with total parathyroidectomy did not show recurrence.

Discussions

After analyzing the obtained results, our conclusion was that total parathyroidectomy is the intervention of choice for patients suffering from secondary hyperparathyroidism when pharmacotherapy fails in order to prevent recurrence of the disease and to correct the metabolic parameters.

Does race impact outcomes after parathyroidectomy for secondary and tertiary hyperparathyroidism?

BACKGROUND

Racial disparities in care exist for diseases with heterogeneous treatment guidelines. The impact of these disparities on outcomes after parathyroidectomy for secondary(2HPT) and tertiary hyperparathyroidism(3HPT) was explored.

METHODS

The 2015-2019 NSQIP datasets were used. Patients who underwent parathyroidectomy for 2HPT and 3HPT were identified and analyzed separately. Patients were stratified by race (white vs. non-white); demographics, comorbidities, and outcomes were compared. Studied outcomes included 30-day morbidity, mortality, unplanned reoperation, readmission, and postoperative length of stay(LOS).

RESULTS

There were 1,150 patients with 2HPT and 262 with 3HPT. For 2HPT, 65.5% were non-white; morbidity, reoperation, and prolonged LOS(>3days) occurred disproportionately more often in non-white patients. Non-white race was independently associated with morbidity; higher ASA class and alkaline phosphatase levels were associated with prolonged LOS. For 3HPT, 53.1% were non-white; a prolonged LOS(>1day) occurred disproportionately more often in non-white patients. Higher alkaline phosphatase levels were independently associated with prolonged LOS.

CONCLUSION

Race and markers of advanced disease negatively impact outcomes after parathyroidectomy for 2HPT and 3HPT. Attention to racial disparities and earlier referral may positively impact outcomes.

In-hospital mortality predictors among hospitalized adults and those with chronic kidney disease with dengue

BACKGROUND

Accurately identifying risk factors that predict fatality in dengue is crucial for patient triage and clinical management. Our objective was to identify predictors of death associated with dengue and investigate the clinical characteristics and risk factors among patients with chronic kidney disease (CKD) who died from dengue.

METHODS

A multicenter longitudinal observation study conducted from 2008 to 2019.

RESULTS

A total of 1272 patients (113 who died and 1186 who recovered) diagnosed with dengue were included. Old age, CKD, and an elevated white blood cell count at hospital presentation were identified as independent predictors of in-hospital mortality among individuals infected with the dengue virus. In a subgroup analysis of 138 patients with CKD infected with dengue virus, 64 (46.3%) patients died, with 46 (33.3%) patients dying within 7 days after symptom onset. Among 64 fatal dengue patients with CKD, 34.4% were in stages 2 and 3 of kidney disease, 51.5% were in stages 4 and 5, and 14.1% had end stage renal disease as per the classification by Kidney Disease Improving Global Outcomes. Multivariate analysis revealed that initial altered consciousness, pulmonary edema, and leukocytosis during hospitalization were independently associated with in-hospital mortality in CKD patients infected with the dengue virus. Leukocytosis during hospitalization and severe hepatitis were independent risk factors for death within 7 days after dengue illness onset in CKD patients.

CONCLUSIONS

This study offers valuable insights into predictors linked to fatality in dengue and reinforces the importance of optimizing patient triage to improve the quality of care.

Early renal impairment affects hormonal regulators of calcium and bone metabolism and Wnt signalling and the response to vitamin D supplementation in healthy older adults

Bone and renal metabolism are regulated by common factors and there is extensive cross-talk between these organs (the 'renal-bone-axis'). Ageing is associated with physiological changes including reduced bone mass, renal function and tissue sensitivity to regulatory hormones, impacting the renal-bone axis. We aimed to investigate the influence of estimated Glomerular Filtration Rate (eGFR) on plasma concentrations of vitamin D metabolites, Wnt signalling and bone metabolism in a dose ranging vitamin D₃ RCT (12,000 IU, 24,000 IU, 48,000 IU/month for 1 year; n = 379, >70 y) with a baseline eGFR > 30 mL/min/1.73 m². Participants were categorised on basis of eGFR (≥60 or mL/min/1.73 m²) based on 5 commonly used algorithms for eGFR. Differences between eGFR categories were tested with ANCOVA. Before supplementation commenced, a lower eGFR was associated with significantly higher concentrations of c-terminal and intact Fibroblast Growth Factor-23 (cFGF23; iFGF23), intact Parathyroid Hormone (iPTH) and Sclerostin (SOST) and lower Klotho, 1,25-dihydroxy Vitamin D (1,25(OH)₂D) and Dickkopf-related Protein 1 (DKK1) concentrations. Differences between eGFR groups in 25-hydroxy Vitamin D (25(OH)D), 24,25-dihydroxy Vitamin D (24,25(OH)₂D) and iPTH were only detected with eGFR based on Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification in Diet for Renal Disease (MDRD-4) algorithms. Differences in Bone Mineral Density and Content (BMD; BMC) and bone turnover markers were detected only with Cockcroft-Gault (CG). Pre- and post- supplementation comparisons showed differences in the response to supplementation by eGFR group. Plasma 25(OH)D, 24,25(OH)₂D, 1,25(OH)₂D and DKK1 increased and iPTH and C-terminal telopeptide (CTX) decreased in both groups. Plasma iFGF23, bone specific alkaline phosphatase (BAP) and Procollagen 1 intact N-terminal Propeptide (PINP) increased and phosphate decreased only in the group with eGFR ≥ 60 mL/min/1.73 m². Findings were largely consistent across all eGFR algorithms. Post-supplementation, cFGF23, iFGF23, iPTH and SOST remained significantly higher in the lower eGFR group. Plasma 1,25(OH)₂D and Klotho did no longer differ between eGFR groups. This was found for all eGFR algorithms, with the exception of iPTH and iFGF23, which were not significantly different with eGFR based on CG. Differences in BMD and BMC were detected with CKD-EPI-creatinine and MDRD-4 but not GC. This study showed that even a moderate decline in eGFR is associated with alterations in vitamin D metabolism, Wnt signalling and bone turnover markers. Renal function influenced the response to vitamin D supplementation. Supplementation increased Vitamin D metabolites in the group with moderate renal impairment to concentrations comparable to those found in the group with normal renal function. However, although CTX decreased, an increase in bone formation markers was not found in the group with eGFR 60 mL/min/1.73 m². In conclusion, vitamin D supplementation had beneficial effects on markers of the renal-bone axis in older people with both normal and impaired renal function.

Missed Opportunities to Diagnose and Treat Tertiary Hyperparathyroidism After Transplant

INTRODUCTION

Tertiary hyperparathyroidism (3HPT) is common after renal transplant. However, guidelines for diagnosis are not clear and few patients are treated surgically. This study aims to determine rates of diagnosis and treatment of 3HPT in renal transplant patients with hypercalcemia.

MATERIALS AND METHODS

This retrospective chart review identified all renal transplant recipients at a single tertiary care institution between 2011 and 2021. Patients with post-transplant hypercalcemia (> 10.2 mg/dL) were identified. The time in months of index hypercalcemia was noted. Measurement of parathyroid hormone (PTH) levels after index hypercalcemia was determined and noted as elevated if > 64 pg/mL at least 6 mo after transplant. Documentation of symptoms of hyperparathyroidism, a diagnosis of hyperparathyroidism in the electronic medical record, and medical or surgical management of patients with classic 3HPT (elevated calcium and PTH) were determined.

RESULTS

Of 383 renal transplant recipients, hypercalcemia was identified in 132 patients. The majority of hypercalcemic patients had PTH levels measured (127, 96.2%). PTH was elevated in 109 (82.6%). Among the 109 patients with classic 3HPT, 54 (49.5%) had a documented diagnosis of hyperparathyroidism in the electronic medical record (P = 0.01). Kidney stones or abnormal DEXA scan were present in 16 (14.7%) and 18 (16.5%), respectively. Most patients were managed non-surgically (101, 92.6%); calcimimetics were prescribed for 42 (38.5%, P = 0.01). Eight (7.3%) patients with classic 3HPT were referred to a surgeon (P = 0.35); all were initially prescribed calcimimetics (P = 0.001).

CONCLUSIONS

3HPT is underdiagnosed in patients with elevated calcium and PTH levels post-transplant. A significant percentage of these patients go without surgical referral and curative treatment.

Vitamin D: sources, physiological role, biokinetics, deficiency, therapeutic use, toxicity, and overview of analytical methods for detection of vitamin D and its metabolites

Vitamin D has a well-known role in the calcium homeostasis associated with the maintenance of healthy bones. It increases the efficiency of the intestinal absorption of dietary calcium, reduces calcium losses in urine, and mobilizes calcium stored in the skeleton. However, vitamin D receptors are present ubiquitously in the human body and indeed, vitamin D has a plethora of non-calcemic functions. In contrast to most vitamins, sufficient vitamin D can be synthesized in human skin. However, its production can be markedly decreased due to factors such as clothing, sunscreens, intentional avoidance of the direct sunlight, or the high latitude of the residence. Indeed, more than one billion people worldwide are vitamin D deficient, and the deficiency is frequently undiagnosed. The chronic deficiency is not only associated with rickets/osteomalacia/osteoporosis but it is also linked to a higher risk of hypertension, type 1 diabetes, multiple sclerosis, or cancer. Supplementation of vitamin D may be hence beneficial, but the intake of vitamin D should be under the supervision of health professionals because overdosing leads to intoxication with severe health consequences. For monitoring vitamin D, several analytical methods are employed, and their advantages and disadvantages are discussed in detail in this review.

Baseline characteristics of participants enrolled in the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD)

BACKGROUND

We developed the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD) as a subcohort of KNOW-CKD to investigate the different characteristics of pediatric CKD between countries and races.

METHODS

Children aged younger than 18 years with stage 1 ~ 5 CKD were recruited at seven major pediatric nephrology centers in Korea. Blood and urine samples, as well as demographic and clinical data, were collected. From 2011 to 2016, 458 children were enrolled, and the baseline profiles of 437 children were analyzed.

RESULTS

The median age of the cohort was 10.9 years old, and 68.0% were males. The median estimated glomerular filtration rate was 53.1 mL/min/1.73 m². The most common etiology of CKD was congenital anomalies of the kidney and urinary tract (42.6%), followed by glomerulopathies (25.6%).

CONCLUSION

We report a cross-sectional analysis of the overall baseline characteristics such as age, CKD stage, and underlying kidney disease of the KNOW-Ped CKD. The cohort will be longitudinally followed for ten years. "A higher resolution version of the Graphical abstract is available as Supplementary information."

A feasibility study of avoiding positive calcium balance and parathyroid hormone increase in patients on peritoneal dialysis

Background

The effect of the dialysate calcium concentration (D[Ca]) on mineral and bone metabolism in patients on peritoneal dialysis (PD) is overlooked. D[Ca] of 1.75 mmol/L is still prescribed to many patients on PD around the world. Previous studies on the effects of reducing D[Ca] have been carried out before the incorporation of calcimimetics in clinical practice. We hypothesized that a reduction in D[Ca] is safe and without the risk of a rise in serum parathyroid hormone (PTH).

Methods

In this non-randomized clinical trial, the D[Ca] was reduced from 1.75 mmol/L to 1.25 mmol/L for one year in prevalent patients on PD. Demographic, clinical, and CKD-MBD-related biomarkers were evaluated at baseline, 3, 6, and 12 months of follow-up.

Results

20 patients completed 1-year follow-up (56 ± 16 years, 50 % male, 25 % diabetic, 55 % with baseline parathyroid hormone – PTH >300 pg/mL). Over time, there was no significant change in calcium, phosphate, total alkaline phosphatase, 25(OH)-vitamin D or PTH, although adjustments in calcitriol and sevelamer prescription were required. After 1 year, absolute and percentual change in PTH levels were 36 (−58, 139) pg/mL, and 20 % (−28, 45) respectively. The proportion of patients with PTH > 300 pg/mL did not change during the follow-up (p = 0.173).

Conclusion

Knowing the risk of a positive calcium balance in patients on PD, reducing the D[Ca] concentration is a safe and valuable option, although medication adjustments are needed to detain PTH rising.

Meta-analyses of the quantitative computed tomography data in dialysis patients show differential impacts of renal failure on the trabecular and cortical bones

Dialysis patients have compromised bone health that increases their fracture risk due to low bone mass and deterioration in bone microarchitecture. Through meta-analyses of published studies, we conclude that dialysis patients suffer from impaired compartmental bone parameters compared with healthy controls.

INTRODUCTION

We performed meta-analyses to determine the effect of chronic kidney disease (CKD) patients under dialysis on the trabecular and cortical parameters of radius and tibia.

METHODS

This is a meta-analysis of cross-sectional and prospective clinical studies. PubMed, Web of Science, Google Scholar, and Scopus were searched using various permutation combinations. Dialysis patients were compared with non-CKD healthy controls using quantitative computed tomography. High-resolution peripheral quantitative computed tomography (HR-pQCT) and pQCT data of dialysis patients were dissected from eligible studies for pooled analysis of each parameter.

RESULTS

Ten studies met the inclusion criteria that included data from 457 dialysis patients and 2134 controls. Pooled analysis showed a significant decrease (a) in total vBMD at distal radius [standard deviation of the mean (SDM) = -0.842, p = 0.000] and tibia (SMD = -0.705, p = 0.000) and (b) in cortical vBMD (SDM = -1.037, p = 0.000) at radius of dialysis patients compared with control. There were strong correlations between total vBMD and microarchitecture parameters at tibia in dialysis patients.

CONCLUSIONS

At radius and tibia, bone mass, microarchitecture, and geometry at trabecular and cortical envelopes displayed impairments in dialysis patients compared with control. Tibial vBMD may have diagnostic value in dialysis. HR-pQCT and pQCT may be used to further understand the compartmental bones response to CKD-induced loss at different stages of CKD.

Higher one-year achievement rate of serum phosphate associated with lower cardiovascular mortality in hemodialysis patients

Background

Estimation of phosphate load in hemodialysis patients is always controversial in clinical practice. The aim of this study was to verify individual achievement rate of serum phosphate as the evaluation of phosphate load through investigating its impact on cardiovascular mortality in hemodialysis patients.

Methods

This was a single-center, retrospective cohort study. A total of 251 maintenance hemodialysis patients were enrolled. The individual achievement rate of serum phosphate was defined as the times of tests within the target range divided by total times of tests over a period of time. Cox regression model was used to examine the relationship between individual achievement rate of serum phosphate and cardiovascular mortality.

Results

The mean age of the study population was 61 ± 13 years old. A total of 44 (17.5%) patients died from cardiovascular disease (CVD) during a median follow-up of 65 months. Multivariable Cox analysis showed that one-year serum phosphate achievement rate of 0% (HR = 4.117, P = 0.016) and 25% (HR = 3.343, P = 0.023) increased the risk of cardiovascular mortality while the achievement rate of 50% (HR = 2.129, P = 0.162) and 75% (HR = 1.080, P = 0.902) did not, compared to the rate of 100%. Urea reduction ratio (URR) was positively, while serum intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), normalized protein catabolic rate (nPCR), and total phosphate-binding capacity of drug were negatively associated with achievement in target of serum phosphate.

Conclusions

Keeping one-year achievement rate of serum phosphate higher than 50% provides significant clinical benefits in reducing cardiovascular mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02547-z.

Comparison of different parathyroid autograft project after total parathyroidectomy in patients with secondary hyperparathyroidism

OBJECTIVE

To evaluate the feasibility and efficacy of total parathyroidectomy followed by modified needle-quantified injection of parathyroid autograft compared with classic incision and transplantation.

METHODS

We conducted a retrospective study of 171 patients with secondary hyperparathyroidism treated by hemodialysis or peritoneal dialysis. These patients were included in our study from April 2006 to December 2016, who had undergone total parathyroidectomies with autotransplantation. Patients were divided into classic incision for transplantation of parathyroid autograft group and modified needle-quantified injection group. Clinical and biochemical characteristics, including preoperative and postoperative intact parathyroid hormone levels were recorded and compared between two group patients.

RESULTS

To compare the techniques of modified needle-quantified injection and classic incision and transplantation, pre- and postoperative biochemistry and length of operation was recorded and analyzed. Preoperative biochemistry was similarly in both groups. However, autograft function achieved was significantly faster in the group with modified needle-quantified injection compared with classic incision and transplantation (P = 0.03). Median time to parathyroid function regain was 3 months for injection compared with 7 months for classic incision. There was no remarkable difference in the recurrence rates between the two groups.

CONCLUSION

The modified needle-quantified injection of parathyroid tissue is a feasible and simple alternative to the more commonly used method of classic incision and transplantation.

Therapy with PTH 1-34 or calcitriol and calcium in diverse etiologies of hypoparathyroidism over 27 years at a single tertiary care center

OBJECTIVE

Hypoparathyroidism has heterogeneous genetic and acquired etiologies with a broad spectrum of severity. Herein we describe the clinical outcomes of the largest cohort of hypoparathyroid patients reported to date, who were followed over 27-years.

DESIGN

Pooled analysis of current and past studies describing the differential responses to PTH 1-34 injections vs conventional therapy among the varied hypoPT etiologies.

METHODS

192 participants (ages 2-74 years) with hypoparathyroidism who received either calcitriol and calcium or PTH 1-34 by subcutaneous injection.

RESULTS

Among the 4 main etiologic categories of hypoparathyroidism (autoimmune polyglandular failure type 1, activating mutation of the calcium receptor, surgical, and idiopathic hypoparathyroidism), we reveal significant differences in PTH 1-34 dose requirements, prevalence of nephrocalcinosis, biomarkers of mineral homeostasis, and pharmacodynamic profiles. Serum 1,25-dihydroxyvitamin D₃ increased significantly (P < 0.001) and 25-hydroxyvitamin D levels decreased during PTH 1-34 injections compared to calcitriol therapy (P < 0.01). Post-surgical patients achieved consistently lower urine calcium excretion over long-term PTH 1-34 therapy compared to conventional therapy (p < 0.001), but this was not achieved in the other etiologies. At study entry, patients had a high prevalence of renal insufficiency and nephrocalcinosis which were directly related to the duration of hypoparathyroidism (P < 0.03). Renal function remained stable during participation in our studies for both PTH 1-34 and conventional therapies.

CONCLUSIONS

We conclude that the effects and dose-response of PTH 1-34 treatment differ according to the etiology of hypoparathyroidism. Postsurgical hypoPT maintained mean serum calcium levels in the mid- to low-normal range while concurrently maintaining normal mean urine calcium during long-term twice-daily PTH 1-34 therapy.

Basal Ganglia Calcification Is Associated With Local and Systemic Metabolic Mechanisms in Adult Hypoparathyroidism

CONTEXT

Hypoparathyroidism is characterized by low serum calcium, increased serum phosphorus, and inappropriately low or decreased serum parathyroid hormone, which may be associated with soft tissue calcification in the basal ganglia of the brain.

OBJECTIVE

To assess the prevalence and factors involved in the pathophysiology of basal ganglia calcification (BGC) in the brain in chronic hypoparathyroidism and to evaluate proposed pathophysiologic mechanisms.

DESIGN

Case-control study with retrospective review of medical records over 20 years.

SETTING

Single academic medical center.

PATIENTS

142 patients with chronic hypoparathyroidism and computed tomography (CT) head scans followed between January 1, 2000 and July 9, 2020, and 426 age- and sex-matched controls with CT head scans over the same interval.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Demographic, biochemical, and CT head imaging findings, with semiquantitative assessment of volumetric BGC.

RESULTS

The study found that 25.4% of 142 patients followed for a median of 17 years after diagnosis of chronic hypoparathyroidism had BGC, which developed at a younger age than in controls. BGC was 5.1-fold more common in nonsurgical patients and less common in postsurgical patients. Low serum calcium and low calcium/phosphate ratio correlated with BGC. Neither serum phosphorus nor calcium × phosphate product predicted BGC. Lower serum calcium was associated with greater volume of BGC. The extent of BGC varied widely, with nonsurgical patients generally having a greater volume and distribution of calcification.

CONCLUSIONS

BGC is associated with low serum calcium and low serum calcium/phosphate ratio, which may be related to severity of the disease, its etiology, or duration of treatment.

Electrolyte Changes in Contemporary Hemodialysis: A Secondary Analysis of the Monitoring in Dialysis (MiD) Study

BACKGROUND

There is a paucity of contemporary data examining electrolyte changes during and immediately after hemodialysis (HD), and their relationship with dialysate prescriptions. The present study examines these relationships.

METHODS

We analyzed patient- (n=66) and HD session-level pre- and post-dialysis laboratory data (n=1,713) over a six-month period from the Monitoring in Dialysis Study. We fit mixed effects regression models to analyze electrolyte, blood urea nitrogen, creatinine, and albumin levels immediately post-HD, accounting for pre-HD and dialysate prescriptions. In a subset of US patients (n=40), 15-minute post-HD and 30-minute post-HD values were available at one session. Predictive models were fit to estimate electrolyte levels immediately post-HD, accounting for pre-HD concentrations and dialysate prescriptions.

RESULTS

Serum bicarbonate, calcium, and albumin increased (mean increase 4.9±0.3 mEq/L, 0.7±0.1 mEq/L, and 0.4±0.03 g/dL, respectively), whereas potassium, magnesium, and phosphorus decreased immediately post-HD (mean -1.2±0.1 mEq/L, -0.3±0.03 mEq/L, and -3.0±0.2 mg/dL, respectively). Hypokalemia and hypophosphatemia were present in 40% of and 67% of immediate post-HD samples, respectively. Dynamic changes were observed in electrolyte concentrations at 15- and 30-minutes post-HD, compared to immediately post-HD.

CONCLUSION

We describe the magnitude of post-dialytic changes in serum electrolytes with contemporary HD, reporting a high incidence of electrolyte abnormalities post-HD, and present predictive nomograms relating electrolyte changes immediately post-HD to dialysate prescriptions. Our results may be useful for clinical care and provide insights for future research on dialysate prescriptions.

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.

Basal ganglia calcification in hypoparathyroidism and pseudohypoparathyroidism: local and systemic metabolic mechanisms

BACKGROUND

Hypoparathyroidism and pseudohypoparathyroidism are rare disorders of mineral metabolism which may be associated with soft tissue calcification in the basal ganglia in the brain, and occasionally the skin and other tissues. The basal ganglia are the most common sites of calcification in the central nervous system in these disorders, and were first associated with this manifestation in a report from the Mayo Clinic in 1939. The reasons why the basal ganglia are a common site of soft tissue calcification in these rare disorders has been a matter of investigation for many years.

FINDINGS

Due to recent increased understanding of phosphate transport and new insights gained from mRNA expression in the basal ganglia, the pathophysiology of basal ganglia calcification (BGC) is now clearer. There is evidence that the absence of parathyroid hormone in hypoparathyroidism may play a direct role, but this is clearly not the case in pseudohypoparathyroidism, which is associated with increased parathyroid hormone levels. Maintaining the calcium/phosphorus ratio as close to normal as possible, and maintaining normal serum phosphate levels, may help mitigate the progression of BGC. There is no evidence of regression of BGC with conventional treatment, and long-term data with adjunctive or replacement therapy with parathyroid hormone or its analogues are not yet available.

PURPOSE OF THE REVIEW

This review will focus on the pathophysiology of BGC in hypoparathyroidism and pseudohypoparathyroidism, and review the proposed pathophysiologic mechanisms, as well as the clinical implications of BGC on patient quality of life.

State-of-the-Art Management of Hyperphosphatemia in Patients With CKD: An NKF-KDOQI Controversies Perspective

Phosphate binders are among the most common medications prescribed to patients with kidney failure receiving dialysis and are often used in advanced chronic kidney disease (CKD). In patients with CKD glomerular filtration rate category 3a (G3a) or worse, including those with kidney failure who are receiving dialysis, clinical practice guidelines suggest "lowering elevated phosphate levels towards the normal range" with possible strategies including dietary phosphate restriction or use of binders. Additionally, guidelines suggest restricting the use of oral elemental calcium often contained in phosphate binders. Nutrition guidelines in CKD suggest<800-1,000mg of calcium daily, whereas CKD bone and mineral disorder guidelines do not provide clear targets, but<1,500mg in maintenance dialysis patients has been previously recommended. Many different classes of phosphate binders are now available and clinical trials have not definitively demonstrated the superiority of any class of phosphate binders over another with regard to clinical outcomes. Use of phosphate binders contributes substantially to patients' pill burden and out-of-pocket costs, and many have side effects. This has led to uncertainty regarding the use and best choice of phosphate binders for patients with CKD or kidney failure. In this controversies perspective, we discuss the evidence base around binder use in CKD and kidney failure with a focus on comparisons of available binders.

The risk of medically uncontrolled secondary hyperparathyroidism depends on parathyroid hormone levels at haemodialysis initiation

BACKGROUND

Optimal parathyroid hormone (PTH) control during non-dialysis chronic kidney disease (ND-CKD) might decrease the subsequent risk of parathyroid hyperplasia and uncontrolled secondary hyperparathyroidism (SHPT) on dialysis. However, the evidence for recommending PTH targets and therapeutic strategies is weak for ND-CKD. We evaluated the patient characteristics, treatment patterns and PTH control over the first year of haemodialysis (HD) by PTH prior to HD initiation.

METHODS

We studied 5683 incident HD patients from 21 countries in Dialysis Outcomes and Practice Patterns Study Phases 4-6 (2009-18). We stratified by PTH measured immediately prior to HD initiation and reported the monthly prescription prevalence of active vitamin D and calcimimetics over the first year of HD and risk of PTH >600 pg/mL after 9-12 months on HD.

RESULTS

The 16% of patients with PTH >600 pg/mL prior to HD initiation were more likely to be prescribed active vitamin D and calcimimetics during the first year of HD. The prevalence of PTH >600 pg/mL 9-12 months after start of HD was greater for patients who initiated HD with PTH >600 (29%) versus 150-300 (7%) pg/mL (adjusted risk difference: 19%; 95% confidence interval : 15%, 23%). The patients with sustained PTH >600 pg/mL after 9-12 months on HD were younger, more likely to be black, and had higher serum phosphorus and estimated glomerular filtration rates at HD initiation.

CONCLUSIONS

Increased PTH before HD start predicted a higher PTH level 9-12 months later, despite greater use of active vitamin D and calcimimetics. More targeted PTH control during ND-CKD may influence outcomes during HD, raising the need for PTH target guidelines in these patients.

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

BACKGROUND AND OBJECTIVES

With multiple medications indicated for mineral metabolism, dialysis providers can apply various strategies to achieve target phosphate and parathyroid hormone (PTH) levels. We describe common prescribing patterns and practice variation in mineral metabolism treatment strategies over the last decade.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a cohort of adults initiating hemodialysis at Dialysis Clinic, Inc. facilities, we assessed prescriptions of vitamin D sterols, phosphate binders, and cinacalcet longitudinally. To identify the influence of secular trends in clinical practice, we stratified the cohort by dialysis initiation year (2006-2008, 2009-2011, and 2012-2015). To measure practice variation, we estimated the median odds ratio for prescribing different mineral metabolism treatment strategies at 12 months post-dialysis initiation across facilities using mixed effects multinomial logistic regression. Sensitivity analyses evaluated strategies used after detection of first elevated PTH.

RESULTS

Among 23,549 incident patients on hemodialysis, there was a decline in vitamin D sterol-based strategies and a corresponding increase in strategies without PTH-modifying agents (i.e., phosphate binders alone or no mineral metabolism medications) and cinacalcet-containing treatment strategies between 2006 and 2015. The proportion with active vitamin D sterol-based strategies at dialysis initiation decreased across cohorts: 15% (2006-2008) to 5% (2012-2015). The proportion with active vitamin D sterol-based strategies after 18 months of dialysis decreased across cohorts: 52% (2006-2008) to 34% (2012-2015). The odds of using individual strategies compared with reference (active vitamin D sterol with phosphate binder) varied from 1.5- to two-fold across facilities in 2006-2008 and 2009-2011 cohorts, and increased to two- to three-fold in the 2012-2015 cohort. Findings were similar in sensitivity analyses starting from first elevated PTH measurement.

CONCLUSIONS

Over time, mineral metabolism management involved less use of vitamin D sterol-based strategies, greater use of both more conservative and cinacalcet-containing strategies, and increased practice variation, suggesting growing equipoise.

Evidence in chronic kidney disease-mineral and bone disorder guidelines: is it time to treat or time to wait?

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is one of the many important complications associated with CKD and may at least partially explain the extremely high morbidity and mortality among CKD patients. The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline document was based on the best information available at that time and was designed not only to provide information but also to assist in decision-making. In addition to the international KDIGO Work Group, which included worldwide experts, an independent Evidence Review Team was assembled to ensure rigorous review and grading of the existing evidence. Based on the evidence from new clinical trials, an updated Clinical Practice Guideline was published in 2017. In this review, we focus on the conceptual and practical evolution of clinical guidelines (from eMinence-based medicine to eVidence-based medicine and 'living' guidelines), highlight some of the current important CKD-MBD-related changes, and underline the poor or extremely poor level of evidence present in those guidelines (as well as in other areas of nephrology). Finally, we emphasize the importance of individualization of treatments and shared decision-making (based on important ethical considerations and the 'best available evidence'), which may prove useful in the face of the uncertainty over the decision whether 'to treat' or 'to wait'.

Meeting Treatment Goals in Patients on Extramural Dialysis in Health Social Security in Mexico

INTRODUCTION

For the majority of renal replacement therapy history, the main treatment option for patients with end-stage renal disease (ESRD) in Mexico has been peritoneal dialysis. However, the use of hemodialysis is overwhelmingly increasing, driving public health care institutions to subrogate this service. Even when the actual hiring model for subrogation is accurate, there is a lack of quality control points in the hemodialysis prescription, poor adherence to clinical practice guidelines, and a few or no record of outcomes in hemodialysis patients of these subrogated services. The objective of this work is to fill this information gap to allow for uniform and safe hemodialysis for patients of Mexico.

MATERIAL AND METHODS

An observational and cross-sectional study was performed, including all patients receiving chronic hemodialysis treatment in subrogated units of Mexican Social Security Institute (IMSS) in the northern region of Mexico City. Clinical and biochemical data as well as hemodialysis dose by Kt/V and urea reduction rate were collected and evaluated. To determine distribution, mean or median and SD or interquartile range were used; for nominal variables, the difference in proportions was estimated using the χ2 test; proportions were analyzed for biochemical values using the statistical package SPSS version 25.

RESULTS

In our study, >60% (485) of the patients were anemic with an average hemoglobin of 9.39 mg/dL (SD ± 1.83); serum calcium was found below 8.4 mg/dL in 51.3% (383) of patients, and only in 45.8% (342) was at an optimal level of this parameter. Only 33.5% of patients have arteriovenous fistula for dialysis access. The hemodialysis dose was optimal in >75% of patients.

CONCLUSIONS

It is necessary to enhance and monitor treatment of comorbidities in patients with ESRD in subrogated hemodialysis units in México. We observed adequate prescription of hemodialysis in a majority of patients, achieving quality control points for removal of nitrogen products. Yet, there is a lack of quality control of comorbidities; therefore, we should aim to optimize treatment for mineral-bone disorder, anemia, and nutritional status.

Alteration of N6-methyladenosine epitranscriptome profile in unilateral ureteral obstructive nephropathy

Aim: To reveal the alterations of N⁶-methyladenosine (m⁶A) epitranscriptome profile in kidney after unilateral ureteral obstruction in mice. Materials & methods: Total renal m⁶A and expressions of methyltransferases and demethylases were detected by colorimetric quantification method, real-time PCR and western blot, respectively. Methylated RNA immunoprecipitation sequencing was performed to map epitranscriptome-wide m⁶A profile. Results: Total m⁶A levels were time-dependent decreased within 1 week, with the lowest level detected at day 7. A total of 823 differentially methylated transcripts in 507 genes were identified. Specifically, demethylated mRNAs selectively acted on multiple pathways, including TGF-β and WNT. Conclusion: m⁶A modification has a functional importance in renal interstitial fibrosis during obstructive nephropathy and might be a promising therapeutic target.

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.

Medium cut-off dialyzers in a large population of hemodialysis patients in Colombia: COREXH registry

Expanded hemodialysis (HDx) provides increased clearance of conventional and large middle molecules through innovative medium cutoff (MCO) membranes. However, there is a paucity of real-world data regarding the benefits and safety of HDx. This large observational study evaluated outcomes among patients in Colombia undergoing HDx at a extended dialysis clinical services provider. This was a prospective single cohort study of prevalent patients who were treated with HDx; baseline information was collected from the most recent data before patients were started on HDx. Patients were followed prospectively for 1 year for changes in serum albumin and other laboratory parameters compared with the baseline. Survival, hospitalization and safety were assessed from the start of HDx. A total of 1000 patients were invited to enroll; 992 patients met the inclusion criteria for data analysis and 638 patients completed the year of follow-up. Seventy-four (8%) patients died during 866 patient-years (PY) of follow-up; the mortality rate was 8.54 deaths/100 PY (95% confidence interval [CI], 6.8-10.7). There were 673 hospitalization events with a rate of 0.79 events/PY (95% CI, 0.73-0.85) with 6.91 hospital days/PY (95% CI, 6.74-7.09). The observed variability from baseline and maximum average change in mean serum albumin levels were -1.8% and -3.5%, respectively. No adverse events were related to the MCO membrane. HDx using an MCO membrane maintains stable serum albumin levels and is safe in terms of nonoccurrence of dialyzer related adverse events.

Targeting Vascular Calcification in Chronic Kidney Disease

Cardiovascular (CV) disease remains an important cause of morbidity and mortality for patients with chronic kidney disease (CKD). Although clustering of traditional risk factors with CKD is well recognized, kidney-specific mechanisms are believed to drive the disproportionate burden of CV disease. One perturbation that is frequently observed at high rates in patients with CKD is vascular calcification, which may be a central mediator for an array of CV sequelae. This review summarizes the pathophysiological bases of intimal and medial vascular calcification in CKD, current strategies for diagnosis and management, and posits vascular calcification as a risk marker and therapeutic target.

Early response of the parathyroid gland to withdrawal of a calcimimetic compound in uremic rats

Little is known about changes in parathyroid cells when calcimimetics are withdrawn. We examined the response of parathyroid glands to cinacalcet (Cina) withdrawal in uremic Sprague-Dawley rats fed a high-phosphate diet to develop secondary hyperparathyroidism and divided into groups treated with vehicle (UC), Cina, and Cina and maxacalcitol (Maxa), a vitamin D receptor activator (CiNa + Maxa). After 2 wk of treatment, vehicle and Cina were withdrawn and Maxa was continued. Rats were analyzed immediately (day 0) and 7 days (day 7) after withdrawal. The Cina and CiNa + Maxa groups had significantly lower parathyroid hormone (PTH) than the UC group on day 0, although PTH in the Cina group reached UC levels on day 7. On day 0, there were significantly more proliferating cell nuclear antigen-positive cells in the UC group compared with normal controls, and this increase was significantly suppressed in the Cina and CiNa + Maxa groups. On day 7, the Cina group, but not the CiNa + Maxa group, showed a significant increase in proliferating cell nuclear antigen-positive cells compared with the UC group. This increase was related to parathyroid cell diameter regression to UC levels, whereas combination treatment maintained diameter suppression. These results indicate that parathyroid growth activity is stimulated by Cina withdrawal, although the PTH level was not further increased. Continuous administration of Cina may be required for optimal control of secondary hyperparathyroidism, and simultaneous use of a vitamin D receptor activator may be advisable during Cina withdrawal.

Nutritional Status and Mortality Predictability for Time-Varying Serum Alkaline Phosphatase in Hemodialysis Patients: A Longitudinal Study

OBJECTIVE

Higher serum alkaline phosphatase (sALP) levels associate with a poor prognosis in maintenance hemodialysis patients. However, little is known about the meaning of lower sALP in this population. We hypothesized that lower sALP concentrations may express nutritional status and survival accordingly.

METHODS

A retrospective, longitudinal cohort study of a clinical database containing the medical records of 554 patients (367 men and 187 women, mean age 67.6 ± 14.2 years) receiving maintenance hemodialysis from November 2007 to July 2018 in a single center was conducted. sALP, nutritional, bone turnover, and inflammatory marker levels were recorded at 0, 6, 12, 18, 24, 30,and 36 months followed by 58 additional months of clinical observations.

RESULTS

The median sALP level was 90.0 (71.0-125.8) U/L. In a linear mixed effects model adjusted for baseline demographics and clinical parameters, each 1.0 U/L increase above the mean sALP at baseline was associated with 0.7% slower rate of decline in geriatric nutritional risk index per 3 years (P = .02 for sALP × time interaction). sALP remained associated with the rate of change in geriatric nutritional risk index, even after controlling for C-reactive protein and intact parathyroid hormone levels. For each 1.0 U/L increase in sALP over time, the fully adjusted all-cause mortality hazard ratio using Cox models with the time-varying risk effect was 0.996 (95% confidence interval 0.993-1.000, P = .04).

CONCLUSIONS

Increasing longitudinal levels of sALP associate with improved nutritional status and lower mortality rates. sALP can be used as an integrated marker, combining the properties of the nutritional marker, the marker of mineral-bone disease and inflammation, according to its levels.

Association between Bone Mineral Density and Severity of Chronic Kidney Disease

OBJECTIVE

We sought to evaluate the association between femoral neck (FN) and lumbar spine (LS) bone mineral densities (BMDs) with severity of chronic kidney disease (CKD) and prevalence of osteopenia or osteoporosis (OP) among the CKD group.

METHODS

Cross-sectional data from 11050 participants aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES) were analyzed. Specifically, Pearson correlation was applied to analyze the relationship between BMD and estimated glomerular filtration rate (eGFR). General linear models (GLMs) were adjusted for potential confounders and used to analyze mean BMD, based on CKD and CKD stages.

RESULTS

FN BMD was positively correlated with the eGFR in the total and male CKD, but not in the female CKD population. LS BMD was not significantly associated with eGFR. After controlling for partial correlations, FN T-score was positively correlated with the eGFR in the total at-risk population. According to FN BMD, OP prevalence was positively associated with CKD stage. However, according to LS BMD, there was no significant association between OP and CKD stage.

CONCLUSION

Our results may explain the higher prevalence of hip fracture, relative to that of the spine, among CKD patients and generate meaningful insights to guide care, prevention, and treatment regimens for CKD patients. However, the fact that this was a cross-sectional study may limit the possibility of drawing concrete conclusions. Nevertheless, these findings open up a new frontier for further studies to uncover the higher decrease of FN BMD compared to LS BMD among CKD cases.

Illness Perceptions, Self-Care Management, and Clinical Outcomes According to Age-Group in Korean Hemodialysis Patients

Illness perception, formed in social-cultural contexts, is the driving force for health behavior. Age difference can affect health outcomes due to its association with socioeconomic status. The purpose of this study is to determine the relationship between illness perception, self-care management, and clinical outcomes according to the age group in hemodialysis patients. A cross-sectional study was conducted. Using the Brief Illness Perception Questionnaire (BIPQ) and Patient Activation Measure (PAM) 13, clinical outcomes, such as serum phosphorus, potassium, hemoglobin, and albumin were investigated in maintenance hemodialysis patients. Illness perception, self-care management, and clinical outcomes in 189 hemodialysis patients were different according to age group. Younger hemodialysis patients had the lowest illness perception and the highest serum phosphorus. Illness perception was associated with self-care management and clinical outcomes. After the adjusted age, the association between illness perception and self-care management and the association between illness perception and phosphorus were reduced, while the association between illness perception and potassium increased. Uncontrolled phosphorus in younger hemodialysis patients can increase the risk of cardiovascular complications and mortality. To improve self-care management and clinical outcomes in hemodialysis patients, reconstruction, or expansion of illness perception needs to be differentiated according to age group.

The Frequency of Routine Blood Sampling and Patient Outcomes Among Maintenance Hemodialysis Recipients

RATIONALE & OBJECTIVE

Surveillance blood work is routinely performed in maintenance hemodialysis (HD) recipients. Although more frequent blood testing may confer better outcomes, there is little evidence to support any particular monitoring interval.

STUDY DESIGN

Retrospective population-based cohort study.

SETTING & PARTICIPANTS

All prevalent HD recipients in Ontario, Canada, as of April 1, 2011, and a cohort of incident patients commencing maintenance HD in Ontario, Canada, between April 1, 2011, and March 31, 2016.

EXPOSURE

Frequency of surveillance blood work, monthly versus every 6 weeks.

OUTCOMES

The primary outcome was all-cause mortality. Secondary outcomes were major adverse cardiovascular events, all-cause hospitalization, and episodes of hyperkalemia.

ANALYTICAL APPROACH

Cox proportional hazards with adjustment for demographic and clinical characteristics was used to evaluate the association between blood testing frequency and all-cause mortality. Secondary outcomes were evaluated using the Andersen-Gill extension of the Cox model to allow for potential recurrent events.

RESULTS

7,454 prevalent patients received care at 17 HD programs with monthly blood sampling protocols (n=5,335 patients) and at 8 programs with blood sampling every 6 weeks (n=2,119 patients). More frequent monitoring was not associated with a lower risk for all-cause mortality compared to blood sampling every 6 weeks (adjusted HR, 1.16; 95% CI, 0.99-1.38). Monthly monitoring was not associated with a lower risk for any of the secondary outcomes. Results were consistent among incident HD recipients.

LIMITATIONS

Unmeasured confounding; limited data for center practices unrelated to blood sampling frequency; no information on frequency of unscheduled blood work performed outside the prescribed sampling interval.

CONCLUSIONS

Monthly routine blood testing in HD recipients was not associated with a lower risk for death, cardiovascular events, or hospitalizations as compared with testing every 6 weeks. Given the health resource implications, the frequency of routine blood sampling in HD recipients deserves careful reassessment.

Benefit-risk balance of native vitamin D supplementation in chronic hemodialysis: what can we learn from the major clinical trials and international guidelines?

For some years, there has been a great renewal of interest in native vitamin D and its major involvement in osseous and non-osseous effects in the organism. Patients in chronic hemodialysis (CHD) constitute a specific population with different physiopathologic characteristics and needs, since morbidity and mortality are strongly correlated with vitamin D insufficiency. Vitamin D supplementation raises very pertinent questions for which we have only partial answers and we lack solid scientific proof to establish certain truths. Thus, we try through this mini-review to analyze the results of the main randomized clinical trials conducted during the last decade, and to discuss international guidelines concerning native vitamin D supplementation in CHD patients. Seven double-blind randomized clinical trials have evaluated native Vitamin D supplementation in CHD patients. These clinical trials began between 2007 and 2013 and studied relatively small samples of patients with an average of 50. All of these trials are important, but do not provide sufficient scientific proof concerning the advantages, consequences, and secondary effects of native vitamin D supplementation in CHD. None of the European, American, English, Asian, Australian, or Canadian recommendations have specified the targets, doses, duration, or the molecule of vitamin D supplementation in the patient on CHD. In 2017, the long-awaited KDIGO recommendations were published and despite the results of clinical trials conducted, the recommendations on native vitamin D supplementation in CHD were very imprecise and sparse, limited to suggesting correction of any state of vitamin D insufficiency or deficiency.

Diagnostic Tests for Vascular Calcification

Vascular calcification (VC) is the heterogeneous endpoint of multiple vascular insults, which varies by arterial bed, the layer of the arterial wall affected, and is propagated by diverse cellular and biochemical mechanisms. A variety of in vivo and ex vivo techniques have been applied to the analysis of VC in preclinical studies, but clinical examination has principally relied on a number of noninvasive and invasive imaging modalities for detection and quantitation. Most imaging methods suffer from suboptimal spatial resolution, leading to the inability to distinguish medial from intimal VC and insufficient sensitivity to detect microcalcifications that are indicative of active mineral deposition and of vulnerable plaques which may be prone to rupture. Serum biomarkers lack specificity for VC and cannot discriminate pathology. Overall, uncertainties surrounding the sensitivity and specificity of different VC testing modalities, the absence of a clear cause-effect relationship, and lack of any evidence-based diagnostic or therapeutic protocols in relation to VC testing in chronic kidney disease has yielded weak or ungraded recommendations for their use in clinical practice. While VC is recognized as a key manifestation of chronic kidney disease-mineral and bone disorder and those with an increasing burden of VC are considered to be at higher cardiovascular risk, routine screening is not currently recommended.

Interventions for preventing bone disease in kidney transplant recipients

BACKGROUND

People who have chronic kidney disease (CKD) have important changes to bone structure, strength, and metabolism. Children experience bone deformity, pain, and delayed or impaired growth. Adults experience limb and vertebral fractures, avascular necrosis, and pain. The fracture risk after kidney transplantation is four times that of the general population and is related to Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) occurring with end-stage kidney failure, steroid-induced bone loss, and persistent hyperparathyroidism after transplantation. Fractures may reduce quality of life and lead to being unable to work or contribute to community roles and responsibilities. Earlier versions of this review have found low certainty evidence for effects of treatment. This is an update of a review first published in 2005 and updated in 2007.

OBJECTIVES

This review update evaluates the benefits and harms of interventions for preventing bone disease following kidney transplantation.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 16 May 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

RCTs and quasi-RCTs evaluating treatments for bone disease among kidney transplant recipients of any age were eligible.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial risks of bias and extracted data. Statistical analyses were performed using random effects meta-analysis. The risk estimates were expressed as a risk ratio (RR) for dichotomous variables and mean difference (MD) for continuous outcomes together with the corresponding 95% confidence interval (CI). The primary efficacy outcome was bone fracture. The primary safety outcome was acute graft rejection. Secondary outcomes included death (all cause and cardiovascular), myocardial infarction, stroke, musculoskeletal disorders (e.g. skeletal deformity, bone pain), graft loss, nausea, hyper- or hypocalcaemia, kidney function, serum parathyroid hormone (PTH), and bone mineral density (BMD).

MAIN RESULTS

In this 2019 update, 65 studies (involving 3598 participants) were eligible; 45 studies contributed data to our meta-analyses (2698 participants). Treatments included bisphosphonates, vitamin D compounds, teriparatide, denosumab, cinacalcet, parathyroidectomy, and calcitonin. Median duration of follow-up was 12 months. Forty-three studies evaluated bone density or bone-related biomarkers, with more recent studies evaluating proteinuria and hyperparathyroidism. Bisphosphonate therapy was usually commenced in the perioperative transplantation period (within 3 weeks) and regardless of BMD. Risks of bias were generally high or unclear leading to lower certainty in the results. A single study reported outcomes among 60 children and adolescents. Studies were not designed to measure treatment effects on fracture, death or cardiovascular outcomes, or graft loss.Compared to placebo, bisphosphonate therapy administered over 12 months in transplant recipients may prevent fracture (RR 0.62, 95% CI 0.38 to 1.01; low certainty evidence) although the 95% CI included the possibility that bisphosphonate therapy might make little or no difference. Fracture events were principally vertebral fractures identified during routine radiographic surveillance. It was uncertain whether any other drug class decreased fracture (low or very low certainty evidence). It was uncertain whether interventions for bone disease in kidney transplantation reduce all-cause or cardiovascular death, myocardial infarction or stroke, or graft loss in very low certainty evidence. Bisphosphonate therapy may decrease acute graft rejection (RR 0.70, 95% CI 0.55 to 0.89; low certainty evidence), while it is uncertain whether any other treatment impacts graft rejection (very low certainty evidence). Bisphosphonate therapy may reduce bone pain (RR 0.20, 95% CI 0.04 to 0.93; very low certainty evidence), while it was very uncertain whether bisphosphonates prevent spinal deformity or avascular bone necrosis (very low certainty evidence). Bisphosphonates may increase to risk of hypocalcaemia (RR 5.59, 95% CI 1.00 to 31.06; low certainty evidence). It was uncertain whether vitamin D compounds had any effect on skeletal, cardiovascular, death, or transplant function outcomes (very low certainty or absence of evidence). Evidence for the benefits and harms of all other treatments was of very low certainty. Evidence for children and young adolescents was sparse.

AUTHORS' CONCLUSIONS

Bisphosphonate therapy may reduce fracture and bone pain after kidney transplantation, however low certainty in the evidence indicates it is possible that treatment may make little or no difference. It is uncertain whether bisphosphonate therapy or other bone treatments prevent other skeletal complications after kidney transplantation, including spinal deformity or avascular bone necrosis. The effects of bone treatment for children and adolescents after kidney transplantation are very uncertain.

Clinical characterization and prognostic implications of metabolic syndrome in patients undergoing peritoneal dialysis at a Chinese center

Objective

Metabolic syndrome (MS) is a common clinical condition associated with cardiovascular disease in patients undergoing peritoneal dialysis (PD); however, its prognostic implication among patients receiving PD remains controversial.

Methods

In a prospective study from January 2013 and June 2016, we enrolled 190 patients undergoing PD and followed them for 46.4 ± 30.7 months. We assessed the associations of clinical characteristics and measurements with diabetes mellitus (DM) status, MS, and prognostic outcomes among the included patients.

Results

We found that DM was associated with shortened duration of dialysis and poor survival. The prevalence of MS was 58.9% among all patients. We found significant differences in age, body weight, body mass index, triglycerides, high-density lipoprotein cholesterol, fasting plasma glucose, leukocytes, platelets, neutrophil percentage, and pre-albumin between patients with and without MS. We found a negative correlation trend between serum intact parathyroid hormone and MS among our patients. The arteriosclerosis index was significantly elevated in the MS group compared with the non-MS group. Serum calcium concentration and frequency of hospital admissions were significantly associated with mortality and technique failure.

Conclusions

MS was positively associated with cardiovascular disease. DM, and hypocalcemia. Frequent hospital admissions can predict poor prognosis in patients undergoing PD.

C-type natriuretic peptide attenuates renal osteodystrophy through inhibition of FGF-23/MAPK signaling

Renal osteodystrophy (ROD) occurs as early as chronic kidney disease (CKD) stage 2 and seems ubiquitous in almost all pediatric patients with CKD stage 5. Fibroblast growth factor (FGF)-23, a bone-derived endocrine regulator of phosphate homeostasis, is overexpressed in CKD and disturbs osteoblast differentiation and matrix mineralization. In contrast, C-type natriuretic peptide (CNP) acts as a potent positive regulator of bone growth. In the present study, we infused CNP into uremic rats and observed whether CNP could attenuate ROD through the inhibition of FGF-23 cascades. In uremic rats, CNP administration significantly alleviated renal dysfunction, calcium phosphate metabolic disorders, hypovitaminosis D, secondary hyperparathyroidism, the decrease in bone turnover markers and retarded bone pathological progression. More importantly, within FGF-23/mitogen-activated protein kinase (MAPK) signaling, the fibroblast growth factor receptor-1, Klotho and alternative (STAT-1/phospho-STAT-1) elements were upregulated by CNP, whereas FGF-23, RAF-1/phospho-RAF-1, and downstream (ERK/phospho-ERK and P38/phospho-P38) elements were paradoxically underexpressed in bone tissue. Therefore, CNP exerts a therapeutic effect on ROD through inhibition of FGF-23/MAPK signaling at the RAF-1 level.

Considerations and controversies in managing chronic kidney disease: An update

PURPOSE

Current considerations and controversies surrounding the management of chronic kidney disease (CKD) are reviewed.

SUMMARY

Patients diagnosed with CKD require a unique clinical approach to prevent medication toxicities and ensure appropriate management of disease-progressing comorbidities, and they require attention to commonly occurring complications that may affect disease control and impact quality of life, including anemia and CKD-bone-mineral disorder (CKD-BMD). Many CKD-related comorbidities put patients at increased cardiovascular risk, including diabetes, hypertension, and hyperlipidemia. Although there are clinical guidelines to help clinicians manage CKD and its related complications and comorbidities, there are many clinical controversies surrounding optimal treatment. Recent literature and clinical studies bring into question multiple controversies regarding the optimal management approach to the patient living with CKD, including the appropriateness of iron and erythropoiesis-stimulating agents (ESAs) for the treatment of anemia and vitamin D supplementation for the prevention of CKD-BMD. While available guidelines can provide clinicians with guidance regarding the appropriate management of the patient with CKD, they often differ dramatically in the optimal approach to the management of comorbidities and complications. For a patient with CKD, the pharmacist has an important role to ensure optimal outcomes, by appropriately managing comorbid conditions and optimizing drug dosing.

CONCLUSION

Multiple controversies regarding the optimal management of patients with CKD, including the appropriateness of iron and ESAs for treatment of anemia and vitamin D supplementation for the prevention of CKD-BMD. Available guidelines differ dramatically in the optimal approach to the management of comorbidities and complications.

Dialysis Prescription and Sudden Death

In the United States, end-stage renal disease patients receiving hemodialysis have an exceedingly high risk of sudden cardiac death (SCD), accounting for 29% of death events, likely relating to their uremic milieu, recurring exposure to fluid and electrolyte fluxes, and underlying cardiovascular pathology. Furthermore, epidemiologic studies have shown that SCD events, as well as mortality and hospitalizations, occur most frequently on the first dialysis day after the long interdialytic gap, suggesting that abrupt fluctuations in the accumulation and removal of electrolytes, fluid, and uremic toxins over the dialysis cycle may be contributory. Some population-based observational studies have suggested that lower dialysate potassium concentrations appear to be associated with a heightened risk of postdialysis cardiac arrest in hemodialysis patients, although the optimal serum-to-dialysate potassium gradient remains unclear. Some observational studies have suggested that low dialysate calcium concentrations and high serum-to-dialysate calcium gradients may predispose patients to SCD. There is ongoing controversy about an association between higher dialysate bicarbonate concentrations and higher risk of cardiac arrest, likely owing to confounding by indication. Some observational studies also have shown that large interdialytic weight gains, fluid retention, and high ultrafiltration rates are linked with higher risk of SCD and mortality. However, there remains considerable controversy regarding the pros and cons of designating a specific upper ultrafiltration limit with extended treatment times as a clinical practice measure, and further studies are needed to define the optimal tools, metrics, targets, and implementation measures for volume control in the hemodialysis population. In this review, we highlight the epidemiology and pathophysiology of how specific aspects of the hemodialysis procedure may relate to the risk of SCD, as well as preventative strategies and future research directions that can address this risk.

Clinical Studies of Interventions to Mitigate Cardiovascular Risk in Peritoneal Dialysis Patients

Cardiovascular disease (CVD) is highly prevalent in the peritoneal dialysis (PD) population, affecting up to 60% of cohorts. CVD is the primary cause of death in up to 40% of PD patients in Australia, New Zealand, and the United States. Cardiovascular mortality rates are reported to be approximately 14 per 100 patient-years, which are 10- to 20-fold greater than those of age- and sex-matched controls. The excess risk of CVD is related to a combination of traditional risk factors (such as hypertension, dyslipidemia, obesity, smoking, sedentary lifestyle, and insulin resistance), nontraditional (kidney disease-related) risk factors (such as anemia, chronic volume overload, inflammation, malnutrition, hyperuricemia, and mineral and bone disorder), and PD-specific risk factors (such as dialysis solutions, glycation end products, hypokalemia, residual kidney function, and ultrafiltration failure). Interventions targeting these factors may mitigate cardiovascular risk, although high-level clinical evidence is lacking. This review summarizes the evidence relating to cardiovascular interventions targeting modifiable CVD risk factors in PD patients, as well as highlighting the key recommendations of the International Society for Peritoneal Dialysis Cardiovascular and Metabolic Guidelines.

Long-Term Parathyroid Hormone 1-34 Replacement Therapy in Children with Hypoparathyroidism

OBJECTIVE

To determine whether multiple daily injections of parathyroid hormone (PTH) 1-34 are safe and effective as long-term therapy for children with hypoparathyroidism.

STUDY DESIGN

Linear growth, bone accrual, renal function, and mineral homeostasis were studied in a long-term observational study of PTH 1-34 injection therapy in 14 children.

METHODS

Subjects were 14 children with hypoparathyroidism attributable to autoimmune polyglandular syndrome type 1 (N = 5, ages 7-12 years) or calcium receptor mutation (N = 9, ages 7-16 years). Mean daily PTH 1-34 dose was 0.75 ± 0.15 µg/kg/day. Treatment duration was 6.9 ± 3.1 years (range 1.5-10 years). Patients were evaluated semiannually at the National Institutes of Health Clinical Center.

RESULTS

Mean height velocity and lumbar spine, whole body, and femoral neck bone accretion velocities were normal throughout the study. In the first 2 years, distal one-third radius bone accrual velocity was reduced compared with normal children (P < .003). Serum alkaline phosphatase correlated with PTH 1-34 dose (P < .006) and remained normal (235.3 ± 104.8 [SD] U/L, N: 51-332 U/L). Mean serum and 24-hour urine calcium levels were 2.05 ± 0.11 mmol/L (N: 2.05-2.5 mmol/L) and 6.93 ± 1.3 mmol/24 hour (N: 1.25-7.5 mmol/24 hour), respectively-with fewer high urine calcium levels vs baseline during calcitriol and calcium treatment (P < .001). Nephrocalcinosis progressed in 5 of 12 subjects who had repeated renal imaging although renal function remained normal.

CONCLUSIONS

Twice-daily or thrice-daily subcutaneous PTH 1-34 injections provided safe and effective replacement therapy for up to 10 years in children with hypoparathyroidism because of autoimmune polyglandular syndrome type 1 or calcium receptor mutation.