K/DOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease

Distribution of HPV types among women with HPV-related diseases and exploration of lineages and variants of HPV 52 and 58 among HPV-infected patients in China: A systematic literature review

To summarize the distribution of types of human papillomavirus (HPV) associated with HPV-related diseases and investigate the potential causes of high prevalence of HPV 52 and 58 by summarizing the prevalence of lineages, sub-lineages, and mutations among Chinese women. We searched PubMed, EMBASE, CNKI, and WanFang from January, 2012 to June, 2023 to identify all the eligible studies. We excluded patients who had received HPV vaccinations. Data were summarized in tables and cloud/rain maps. A total of 102 studies reporting HPV distribution and 15 studies reporting HPV52/HPV58 variants were extracted. Among Chinese women, the top five prevalent HPV types associated with cervical cancer (CC) were HPV16, 18, 58, 52, and 33. In patients with vaginal cancers and precancerous lesions, the most common HPV types were 16 and 52 followed by 58. For women with condyloma acuminatum (CA), the most common HPV types were 11 and 6. In Chinese women with HPV infection, lineage B was the most prominently identified for HPV52, and lineage A was the most common for HPV58. In addition to HPV types 16, which is prevalent worldwide, our findings revealed the unique high prevalence of HPV 52/58 among Chinese women with HPV-related diseases. HPV 52 variants were predominantly biased toward lineage B and sub-lineage B2, and HPV 58 variants were strongly biased toward lineage A and sub-lineage A1. Further investigations on the association between the high prevalent lineage and sub-lineage in HPV 52/58 and the risk of cancer risk are needed. Our findings underscore the importance of vaccination with the nine-valent HPV vaccine in China.

Bilateral rupture of the quadricipital tendon in patients with chronic kidney disease: The peculiarities of management (case report)

INTRODUCTION

Bilateral forms of quadricipital tendon rupture are rare. They are usually associated with predisposing factors, such as secondary hyperparathyroidism due to chronic renal failure, which need to be treated to avoid recurrence.

PRESENTATION OF CASE

A 38-year-old man with a medical history of chronic kidney failure was presented to the hospital for bilateral quadricipital tendon ruptures after a low-energy trauma. Ruptures were in the midportion of the tendon on the right side and in the level of patellar insertion on the left side. We performed a surgical reparation. One year after surgery, he consulted for a recurrence of the left quadricipital tendon rupture after an impeded extension movement. Biology showed secondary hyperparathyroidism due to chronic renal failure. Surgical reparation and reconstruction by a graft tendon were performed. As for his secondary hyperparathyroidism, he got a sub-parathyroidectomy after medical treatment failure. Recovery was remarkably uneventful.

DISCUSSION

Despite the early diagnosis and treatment of a bilateral quadricipital tendons rupture, our patient had an iterative rupture. His secondary hyperparathyroidism due to chronic renal failure may weaken the tendon system through physiological and histological modifications, as it is reported in the literature. As a result, treating a bilateral rupture as a banal post-traumatic lesion without management of the predisposing factors may lead to recurrences.

CONCLUSION

A non or low-traumatic tendon rupture in a patient with a history of chronic renal failure needs to identify secondary hyperparathyroidism, which must be treated to avoid recurrences.

Apparent Treatment-Resistant Hypertension in the First Year Associated With Cardiovascular Mortality in Peritoneal Dialysis Patients

BACKGROUND

Few reports have focused on the association between apparent treatment-resistant hypertension (aTRH) and cardiovascular (CV) mortality in peritoneal dialysis (PD) population, thus we conducted this retrospective cohort to explore it.

METHODS

This was a retrospective cohort study conducted from January 2011 to January 2020 with PD patients in 4 Chinese dialysis centers. aTRH was defined according to the American College of Cardiology and American Heart Association guidelines. aTRH duration was calculated as the total number of months when patients met the diagnostic criteria in the first PD year. The primary outcome was CV mortality, and the secondary outcomes were CV events, all-cause mortality, combined endpoint (all-cause mortality and transferred to hemodialysis [HD]), and PD withdrawal (all-cause mortality, transferred to HD, and kidney transplantation). Cox proportional hazards models were used to assess the association.

RESULTS

A total of 1,422 patients were finally included in the analysis. During a median follow-up period of 26 months, 83 (5.8%) PD patients incurred CV mortality. The prevalence of aTRH was 24.1%, 19.9%, and 24.6% at 0, 3, and 12 months after PD initiation, respectively. Overall, aTRH duration in the first PD year positively associated with CV mortality (per 3 months increment, adjusted hazards ratio [HR], 1.29; 95% confidence interval 1.10, 1.53; P = 0.002). After categorized, those with aTRH duration more than 6 months presented the highest adjusted HR of 2.92. Similar results were found for secondary outcomes, except for the CV event.

CONCLUSIONS

Longer aTRH duration in the first PD year is associated with higher CV mortality and worse long-term clinical outcomes. Larger studies are warranted to confirm these findings.

CLINICAL TRIALS REGISTRATION

There is no clinical trial registration for this retrospective study.

Chronic kidney disease in postmenopausal women is associated with tooth loss

OBJECTIVE

Menopause is characterized by changes in reproductive hormone levels that can negatively affect bone. Chronic kidney disease (CKD) and tooth loss are also important and common health issues after menopause. This study aimed to evaluate the association between CKD and tooth loss in postmenopausal women.

METHODS

The study evaluated 64,971 participants who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) from 2010-2018, including postmenopausal women, aged 40 to 79 years. Participants were divided into two groups based on the number of teeth in their dentition (≥20 and <20).

MAIN OUTCOME MEASURES

The association between CKD and tooth loss was analyzed using multivariate logistic regression. Age, income, education, smoking, alcohol intake, body mass index, hypertension, diabetes, annual oral examination, toothbrushing, and the use of oral care products were considered. Subgroup analyses were further conducted according to age (40-65 yr and 66-79 yr).

RESULTS

After adjusting for covariates, CKD and estimated glomerular filtration rate were significantly associated with having ≥20 teeth (PT20; CKD: odds ratio [OR] 1.41, 95% confidence interval [CI] 1.04-1.90; estimated glomerular filtration rate (10 mL/min/1.73 m2): OR 0.90, 95% CI 0.86-0.94). Importantly, the association between CKD and PT20 was significant in postmenopausal women, aged 66 to 79 years (OR 1.45, 95% CI 1.05-2.01).

CONCLUSIONS

In postmenopausal women, CKD and tooth loss may be associated. The association is significant in postmenopausal women, aged 66 to 79 years.

Aberrant Splicing of COL4A5 Intronic Variant Contribute to the Pathogenesis of X-Linked Alport Syndrome: A Case Series

Introduction

X-linked Alport syndrome (XLAS) is caused by pathogenic variants in COL4A5 which lead to abnormalities of the glomerular basement membrane (GBM) structural and is characterized by progressive kidney disease, hearing loss, and ocular abnormalities. The aim of this study was to identify gene mutations in a Chinese family with XLAS by whole-exome sequencing (WES) and verified the pathogenicity of the mutation in vitro experiments.

Case Presentation

A five-generation pedigree with a total of 49 family members originating from Hainan province of China was investigated in this study. The proband was a 23-year-old male who developed microscopic hematuria, proteinuria and end-stage kidney disease (ESKD) at age 17. WES identified a novel splicing mutation c.321+5G>A of COL4A5, which cause exon skip. Further co-segregation analysis confirmed that this mutation exists in relatives who had renal abnormalities using Sanger sequencing. According to American College of Medical Genetics and Genomics guidelines (ACMG), the mutation was determined to be of uncertain significance (VUS). In vitro splicing experiments have shown that the COL4A5 variant induces aberrant mRNA splicing and transcript deletion.

Conclusion

We identified a novel intronic COL4A5 pathogenic mutation (c.321+5G>A) in a Chinese XLAS family and described the phenotypes of affected relatives. This study expands the mutation spectrum of COL4A5 gene in XLAS and demonstrates the importance of gene screening for AS.

Association between statin therapy and long-term clinical outcomes in patients with stable coronary disease undergoing percutaneous coronary intervention

This longitudinal cohort study examined the long-term effect of statin therapy on clinical outcomes in patients undergoing percutaneous coronary intervention (PCI). A total of 1760 patients with stable coronary artery disease (CAD) were divided by receipt of statin therapy or not after index PCI. Baseline clinical characteristics, risk factors, angiographic findings, and medications after interventional procedure were assessed to compare long-term clinical outcomes between groups. Predictors for all-cause death and major adverse cardiovascular events (MACE), including myocardial infarction (MI), cardiovascular death, and repeated PCI procedures, were also analyzed. The statin therapy group had higher average serum cholesterol and more elevated low-density lipoprotein cholesterol (LDL-C) than the non-statin therapy group (189.0 ± 47.9 vs 169.3 ± 37.00 mg/dl, 117.2 ± 42.6 vs 98.7 ± 31.8 mg/dl, respectively, both P < 0.001). The non-statin group had higher rates of all-cause death and cardiovascular death compared to statin group (both P < 0.001). After adjustment for age, diabetes, and chronic kidney disease, Cox proportion hazard analysis revealed statin use significantly reduced all-cause death and repeated PCI procedure (hazard ratio: 0.53 and 0.69, respectively). Statin use seemed not reduce the hazard of cardiovascular death or MI in patients with stable CAD after PCI; however, statin therapy still was associated with reduced rates of all-cause death and repeat PCI procedure.

Hemodialysis Procedures for Stable Incident and Prevalent Patients Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance

The demographic profile of patients transitioning from chronic kidney disease to kidney replacement therapy is changing, with a higher prevalence of aging patients with multiple comorbidities such as diabetes mellitus and heart failure. Cardiovascular disease remains the leading cause of mortality in this population, exacerbated by the cardiovascular stress imposed by the HD procedure. The first year after transitioning to hemodialysis is associated with increased risks of hospitalization and mortality, particularly within the first 90-120 days, with greater vulnerability observed among the elderly. Based on data from clinics in Fresenius Medical Care Europe, Middle East, and Africa NephroCare, this review aims to optimize hemodialysis procedures to reduce mortality risk in stable incident and prevalent patients. It addresses critical aspects such as treatment duration, frequency, choice of dialysis membrane, dialysate composition, blood and dialysate flow rates, electrolyte composition, temperature control, target weight management, dialysis adequacy, and additional protocols, with a focus on mitigating prevalent intradialytic complications, particularly intradialytic hypotension prevention.

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.

Impact of hyperparathyroidism on allograft histology and function after kidney transplantation: Rethinking its causal role in graft dysfunction

INTRODUCTION

The causal relationship between hyperparathyroidism and kidney graft dysfunction remains inconclusive. Applying Bradford-Hill's temporality and consistency causation principles, we assessed the effect of parathyroid hormone (iPTH) on graft histology and eGFR trajectory on kidney transplant recipients (KTRs) with normal time-zero graft biopsies.

METHODS

Retrospective cohort study evaluating the effect of hyperparathyroidism on interstitial fibrosis and tubular atrophy (IF/TA) development in 1232 graft biopsies. Pre-transplant hyperparathyroidism was categorized by KDIGO or KDOQI criteria, and post-transplant hyperparathyroidism by iPTH >1× and >2× the URL 1 year after transplantation.

RESULTS

We included 325 KTRs (56% female, age 38 ± 13 years, follow-up 4.2 years [IQR: 2.7-5.8]). Based on pre-transplant iPTH levels, 26% and 66% exceeded the KDIGO and KDOQI targets, respectively. There were no significant differences in the development of >25% IF/TA between KTRs with pre-transplant iPTH levels above and within target range according to KDIGO (53% vs. 62%, P = .16, HR.94 [95% CI:.67-1.32]) and KDOQI (60% vs. 60%, P = 1.0, HR 1.19 [95% CI:.88-1.60]) criteria. Similarly, there were no differences when using 1 year post-transplant iPTH cut-offs > 88 pg/mL (58% vs. 64%, P = .33) and > 176 pg/mL (55% vs. 62%, P = .19). After adjusting for confounders, no significant differences were observed in eGFR trajectories among the iPTH strata.

CONCLUSION

In young KTRs who received a healthy graft, no association was found between increased pre- and post-transplant iPTH levels and graft dysfunction, as assessed histologically and through eGFR trajectory. The concept of hyperparathyroidism as a risk factor for graft dysfunction in recipients at low risk requires reevaluation.

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

A Systematic Review of Online Resources for the Dietary Management of Hyperphosphatemia in People With Chronic Kidney Disease

OBJECTIVE

Internet search engines and social media websites are prominent and growing sources of dietary information for people with chronic kidney disease (CKD) and their healthcare providers. However, nutrition therapy for CKD is undergoing a paradigm shift, which may lead to inconsistent advice for managing hyperphosphatemia. The aim of this study was to summarize and evaluate online resources for phosphorus-specific nutrition therapy.

DESIGN AND METHODS

Patient-facing resources were collected from Google, Yahoo, and Facebook in June-July 2021. Using nine independent search terms, the first 100 hits were reviewed. Dietary advice for food types, food groups, food subgroups, and individual food items was categorized as "restricted," "recommended," "mixed," and "not mentioned." Information on publication date, source, and author(s), phosphorus bioavailability, and demineralization were also collected.

RESULTS

After removing duplicates, 199 resources from Google and Yahoo and 33 from Facebook were reviewed. Resources ranged from 2005 to 2021 and were primarily authored by registered dietitians and medical doctors (65% and 31%, respectively). Dietary advice mostly focuses on restricting high-phosphorus foods and phosphorus additive-based processed foods. Dietary restrictions were generally consistent with the traditional low-phosphorus diet, which targets whole grains, dairy, and plant-based protein foods, although major inconsistencies were noted. Phosphorus bioavailability and demineralization were rarely mentioned (16% and 8%, respectively). Similar findings were found on Facebook, but the limited number of resources limited meaningful comparisons.

CONCLUSION

Results showed that online resources for phosphorus-specific nutrition therapy are highly restrictive of heart-healthy food items and contain significant inconsistencies. Given the widespread and increasing use of online resources by people with CKD and health care professionals to inform dietary choices, efforts are urgently needed to establish consensus for phosphorus-specific nutrition therapy. Until then, the findings of this study provide a basis for increasing awareness of the potential for confusion arising from online resources.

Prevalence, Risk Factors, and Management of Metabolic Acidosis in Chronic Kidney Disease Patients: A Multicenter Retrospective Study in Malaysia

Background Metabolic acidosis in chronic kidney disease (CKD) patients has lately gained attention due to the growing evidence of its treatment benefits. This study aims to provide baseline data on the prevalence, risk factors, and current management of metabolic acidosis among the pre-dialysis adult Malaysian CKD population. Methodology This multicenter cross-sectional retrospective study involved pre-dialysis CKD patients above 18 years old on regular nephrology clinic follow-up at three Malaysian government hospitals with nephrology subspecialty. Demographic data, clinical information, laboratory data, and a list of concomitant medications were collected. Factors associated with the occurrence of metabolic acidosis were identified via multiple logistic regression. Results Six hundred and fifty-seven CKD patients were screened for this study, in which only 39.4% (n=259) had available bicarbonate levels. From this, a total of 86.1% (n=223) had metabolic acidosis. Higher estimated glomerular filtration rate (odds ratio (OR) 0.96, 95% confidence interval (CI) 0.93-1.00, p=0.043) and those with cardiovascular disease (OR 0.33, 95% CI 0.15-0.73; p=0.007) were significantly associated with lower odds of metabolic acidosis. There were 43.0% (n=96) on alkali therapy with sodium bicarbonate solution being the most common (n=91, 94.8%). Among those receiving alkali therapy, only 19.8% (n=19) achieved bicarbonate levels of ≥ 22 mEq/L. Conclusion Our study showed that metabolic acidosis was highly prevalent, although few achieved target levels despite supplementation, supporting the need for focused management of metabolic acidosis in the CKD population.

Hyperparathyroidism, Serum Phosphorus and Dietary Intake in Hemodialysis Patients: Is There a Novel Relationship?

The management of hyperparathyroidism (intact parathyroid hormone (iPTH) serum levels > 585 pg/mL), frequently focuses on the appropriate control of mineral and bone markers, with the decrease in serum and dietary phosphorus as two of the targets. We aimed to investigate the association between iPTH, serum phosphorus levels and dietary intake. This was a cross-sectional, multicenter, observational study with 561 patients on hemodialysis treatment. Clinical parameters, body composition and dietary intake were assessed. For the analysis, patients were divided into three groups: (a) iPTH < 130, (b) iPTH between 130 and 585 and (c) iPTH > 585 pg/mL. The association between PTH, serum phosphorus and dietary intake was analyzed using linear regression models. In the whole sample, 23.2% of patients presented an iPTH > 585 pg/mL. Patients with higher iPTH levels were those with longer HD vintage and lower ages, higher serum phosphorus, serum calcium, Ca/P product, albumin and caffeine intake, and a lower dietary intake of phosphorus, fiber, riboflavin and folate. Higher serum phosphorus predicted higher iPTH levels, even in the adjusted model. However, lower dietary phosphorus and fiber intake were predictors of higher iPTH levels, including in the adjusted model. Our results bring new data to the relationship between dietary intake and iPTH values. Despite higher serum phosphorus being observed in patients with HPTH, an opposite association was noted regarding dietary phosphate and fiber.

Recommended calcium intake in adults and children with chronic kidney disease-a European consensus statement

Mineral and bone disorders (MBD) are common in patients with chronic kidney disease (CKD), contributing to significant morbidity and mortality. For several decades, the first-line approach to controlling hyperparathyroidism in CKD was by exogenous calcium loading. Since the turn of the millennium, however, a growing awareness of vascular calcification risk has led to a paradigm shift in management and a move away from calcium-based phosphate binders. As a consequence, contemporary CKD patients may be at risk of a negative calcium balance, which, in turn, may compromise bone health, contributing to renal bone disease and increased fracture risk. A calcium intake below a certain threshold may be as problematic as a high intake, worsening the MBD syndrome of CKD, but is not addressed in current clinical practice guidelines. The CKD-MBD and European Renal Nutrition working groups of the European Renal Association (ERA), together with the CKD-MBD and Dialysis working groups of the European Society for Pediatric Nephrology (ESPN), developed key evidence points and clinical practice points on calcium management in children and adults with CKD across stages of disease. These were reviewed by a Delphi panel consisting of ERA and ESPN working groups members. The main clinical practice points include a suggested total calcium intake from diet and medications of 800-1000 mg/day and not exceeding 1500 mg/day to maintain a neutral calcium balance in adults with CKD. In children with CKD, total calcium intake should be kept within the age-appropriate normal range. These statements provide information and may assist in decision-making, but in the absence of high-level evidence must be carefully considered and adapted to individual patient needs.

Biomonitoring of Oxidative-Stress-Related Genotoxic Damage in Patients with End-Stage Renal Disease

Chronic kidney disease (CKD), a common progressive renal failure characterized by the permanent loss of functional nephrons can rapidly progress to end-stage renal disease, which is known to be an irreversible renal failure. In the therapy of ESRD, there are controversial suggestions about the use of regular dialysis, since it is claimed to increase oxidative stress, which may increase mortality in patients. In ESRD, oxidative-stress-related DNA damage is expected to occur, along with increased inflammation. Many factors, including heavy metals, have been suggested to exacerbate the damage in kidneys; therefore, it is important to reveal the relationship between these factors in ESRD patients. There are very few studies showing the role of oxidative-stress-related genotoxic events in the progression of ESRD patients. Within the scope of this study, genotoxic damage was evaluated using the comet assay and 8-OHdG measurement in patients with ESRD who were undergoing hemodialysis. The biochemical changes, the levels of heavy metals (aluminum, arsenic, cadmium, lead, and mercury) in the blood, and the oxidative biomarkers, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels were evaluated, and their relationship with genotoxic damages was revealed. Genotoxicity, oxidative stress, and heavy-metal levels, except mercury, increased significantly in all renal patients. DNA damage, 8OHdG, and MDA significantly increased, and GSH significantly decreased in patients undergoing dialysis, compared with those not having dialysis. The duration and the severity of disease was positively correlated with increased aluminum levels and moderate positively correlated with increased DNA damage and cadmium levels. In conclusion, this study revealed that the oxidative-stress-related DNA damage, and also the levels of Al and Cd, increased in ESRD patients. It is assumed that these changes may play an important role in the progression of renal damage. Approaches for reducing oxidative-stress-related DNA damage and heavy-metal load in ESRD patients are recommended.

Personalizing electrolytes in the dialysis prescription: what, why and how?

Maintenance hemodialysis patients suffer from multiple comorbidities and treatment-related complications. A personalized approach to hemodialysis prescription could reduce some of these burdens by preventing complications such as excessive changes in blood pressure, arrhythmias, post-dialysis fatigue and decreased quality of life. A patient-centered approach to dialysate electrolyte concentrations represents one such opportunity. In addition to modifications in dialysate electrolyte concentrations, consideration of individual factors such as patients' serum concentrations, medication profiles, nutritional status and comorbidities is critical to tailoring hemodialysis prescriptions to optimize patient outcomes. The development of personalized dialysis treatment depends on the collection of comprehensive patient data, advances in technology, resource allocation and patient involvement in decision-making. This review discusses how the treatment of maintenance hemodialysis patients could benefit from individualized changes in certain dialysis fluid components.

Oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: A pilot randomised controlled trial

OBJECTIVE

Peritoneal dialysis (PD)-related peritonitis is independently associated with low serum 25-hydroxy vitamin D [25(OH)D] levels. Our objective is to examine the feasibility of conducting a large, randomised controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis.

DESIGN

Pilot, prospective, open-label randomised controlled trial.

SETTING

Peking University First Hospital, China.

PARTICIPANTS

Patients receiving PD who had recovered from a recent episode of peritonitis between 30 September 2017 and 28 May 2020.

INTERVENTIONS

Oral natural vitamin D supplementation (2000 IU per day) versus no vitamin D supplementation for 12 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25(OH)D level during follow-up) for a large, randomised controlled trial in the future to determine the effects of vitamin D on PD-related peritonitis. Secondary outcomes were time to peritonitis occurrence and outcome of subsequent peritonitis.

RESULTS

Overall, 60 among 151 patients were recruited (recruitment rate was 39.7%, 95% CI 31.9-47.5%, recruitment rate among eligible patients was 61.9%, 95% CI 52.2-71.5%). Retention and adherence rates were 100.0% (95% CI 100.0-100.0%) and 81.5% (95% CI 66.8-96.1%), respectively. During follow-up, serum 25(OH)D levels increased in the vitamin D (VD) group (from 19.25 ± 10.11 nmol/L to 60.27 ± 23.29 nmol/L after 6 months, p < 0.001, n = 31), and remained higher (p < 0.001) than those in the control group (n = 29). No differences were observed between the two groups with respect to time to subsequent peritonitis (hazard ratio 0.85, 95% CI 0.33-2.17) or any of the peritonitis outcomes. Adverse events were uncommon.

CONCLUSIONS

A randomised controlled trial of the effect of vitamin D supplementation on peritonitis occurrence in patients receiving PD is feasible, safe and results in adequate serum 25(OH)D levels.

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

RATIONALE & OBJECTIVE

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

STUDY DESIGN

Two observational clinical trial emulations.

SETTING & PARTICIPANTS

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

EXPOSURE

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

OUTCOME

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

ANALYTICAL APPROACH

Pooled logistic regression.

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

PLAIN-LANGUAGE SUMMARY

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

Phase 2 study of upacicalcet in Japanese haemodialysis patients with secondary hyperparathyroidism: an intraindividual dose-adjustment study

Background

Upacicalcet is a novel small-molecule calcimimetic agent developed for intravenous injection. Here, we evaluated the long-term efficacy and safety of upacicalcet treatment via intraindividual dose adjustment in haemodialysis patients with secondary hyperparathyroidism (SHPT).

Methods

A phase 2, multicentre, open-label, single-arm study was conducted. Upacicalcet was administered for 52 weeks; the starting dose was 50 μg thrice a week, and then adjusted to 25, 50, 100, 150, 200, 250, or 300 μg, according to the dose-adjustment method set in the protocol. The primary endpoint was the percentage of patients with serum intact parathyroid hormone (iPTH) level achieving a target range of 60-240 pg/mL (target achievement rate) at week 18.

Results

A total of 58 patients were administered upacicalcet. The target achievement rate of serum iPTH level at week 18 was 57.9%, which increased to 80.8% at week 52. The serum-corrected calcium (cCa) level decreased immediately after upacicalcet administration, but no further decrease was observed. Adverse events were observed in 94.8% of patients, and adverse drug reactions (ADRs) occurred in 20.7% of patients. The most common ADR was decreased adjusted calcium in eight patients; dizziness occurred as a serious ADR in one patient. The serum cCa level of patients who interrupted upacicalcet treatment at a serum cCa level of <7.5 mg/dL recovered to ≥7.5 mg/dL immediately after the interruption.

Conclusions

In haemodialysis patients with SHPT, upacicalcet doses of 25-300 μg for 52 weeks were found to be highly effective and well-tolerated, with minor safety concerns.

Association between serum total cholesterol and chronic kidney disease progression in children: results from the KNOW-PedCKD

BACKGROUND

Dyslipidemia can cause cardiovascular disease and increase the fatality rate among children with chronic kidney disease (CKD); this makes early screening and treatment of dyslipidemia crucial. This study aimed to assess the association between the changes in serum total cholesterol levels over time and the degree of CKD progression in children.

METHODS

From April 2011 to August 2021, 379 of the 432 participants enrolled in the KoreaN cohort study for Outcomes in patients With Pediatric CKD (KNOW-PedCKD) were included and divided into 4 categories based on total cholesterol levels (< 170 mg/dL, acceptable; 170-199, borderline; 200-239, high; and ≥ 240, very high). Survival analysis using conventional and time-dependent Cox proportional hazards model were performed for a composite event of CKD progression (≥ 50% decrease in estimated glomerular filtration rate from baseline, a twofold increase in creatinine, or the occurrence of dialysis or kidney transplantation).

RESULT

The incidence of composite event of CKD progression was 96.3, 90.4, 87.3, and 270.6 cases per 1000 person-years in the acceptable, borderline, high, and very high categories, respectively. On using the time-dependent Cox proportional hazards model, the hazard ratio of the very high category was significantly higher than that of the acceptable category by 3.13 times as per univariate analysis and 2.37 times as per multivariate analysis.

CONCLUSIONS

Very high serum total cholesterol is a significant risk factor for CKD progression in children. Lowering total cholesterol levels below the very high category in children with CKD may delay the progression of CKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Long-term effects of hypercalcemia in kidney transplant recipients with persistent hyperparathyroidism

BACKGROUND

Hypercalcemia is highly prevalent in kidney transplant recipients with hyperparathyroidism. However, its long-term impact on graft function is uncertain.

METHODS

We conducted a prospective cohort study investigating adverse graft outcomes associated with persistent hypercalcemia (free calcium > 5.2 mg/dL in ≥ 80% of measures) and inappropriately elevated intact parathyroid hormone (> 30 pg/mL) in kidney transplant recipients. Asymptomatic mild hypercalcemia was monitored unless complications developed.

RESULTS

We included 385 kidney transplant recipients. During a 4-year (range 1-9) median follow-up time, 62% of kidney transplant recipients presented persistent hypercalcemia. Compared to kidney transplant recipients without hypercalcemia, there were no significant differences in graft dysfunction (10% vs. 12%, p = 0.61), symptomatic urolithiasis (5% vs. 3%, p = 0.43), biopsy-proven calcium deposits (6% vs. 5%, p = 1.0), fractures (6% vs. 4%, p = 0.64), and a composite outcome of urolithiasis, calcium deposits, fractures, and parathyroidectomy indication (16% vs. 13%, p = 0.55). In a subset of 76 kidney transplant recipients, subjects with persistent hypercalcemia had higher urinary calcium (median 84 [43-170] vs. 38 [24-64] mg/day, p = 0.03) and intact fibroblast growth factor 23 (median 36 [24-54] vs. 27 [19-40] pg/mL, p = 0.04), and lower 25-hydroxyvitamin D levels (11.3 ± 1.2 vs. 16.3 ± 1.4 ng/mL, p < 0.001). In multivariate analysis, pretransplant intact parathyroid hormone < 300 pg/mL was associated with a reduced risk of post-transplant hypercalcemia (OR 0.51, 95% CI 0.32-0.80).

CONCLUSIONS

Long-term persistent mild hypercalcemia (tertiary hyperparathyroidism) was frequent in kidney transplant recipients in our series. This condition presented with lower phosphate and 25-hydroxyvitamin D, and higher urinary calcium and intact fibroblast growth factor 23 levels compared to kidney transplant recipients without hypercalcemia, resembling a mild form of primary hyperparathyroidism. Despite these metabolic derangements, the risk of adverse graft outcomes was low.

Surgical treatment of tertiary hyperparathyroidism: does one fit for all?

Background

Tertiary hyperparathyroidism (3HPT) is defined as a condition of excessive autonomous excretion of intact parathyroid hormone (iPTH) with persistent hypercalcemia (>10.5 mg/dL) that lasts for more than 12 months after a successful kidney transplantation, in the context of a long course secondary hyperparathyroidism (2HPT). The chronic high levels of iPTH cause a worsening of graft function, accompanied by systemic symptoms of hypercalcemia. The only curative therapy is parathyroidectomy (PTX). It remains unclear whether total parathyroidectomy with autotransplantation (TPTX-AT) or subtotal parathyroidectomy (SPTX) lead to better outcomes.

Aims

The aim of this retrospective, single-institution cohort study is to evaluate the rate of persistent or recurrent disease and postoperative calcium/iPTH disturbances in patients treated with TPTX-AT or SPTX for 3HPT.

Methods

A single-center retrospective analysis of 3HPT patients submitted to TPTX-AT or SPTX between 2007-2020 with at least 24 months follow-up was conducted. The outcome parameters included persistence/recurrence of disease, incidence of transitory hypocalcemia, and temporary/permanent hypoparathyroidism.

Results

A cohort of 52 patients was analyzed and divided in two groups: 38 (73%) were submitted for TPTX-AT, and 14 patients (27%) were submitted for SPTX. The TPTX-AT population showed lower plasmatic calcium concentrations compared with the SPTX group during the entire follow-up period (p<0.001). There were eight cases (21%) of transitory hypocalcemia in the TPTX-AT group and none in the SPTX group, with p=0.065. Two cases (5%) of temporary hypoparathyroidism occurred in the TPTX-AT group and none in the SPTX group, with p= 0.530. There were no cases of permanent hypoparathyroidism and no cases of persistent disease. No statistical difference was assessed for the recurrence of 3HPT between the TPTX-AT group and the SPTX group (N=1, 3% vs N=1, 7%) (p=0.470).

Conclusion

No significative difference was registered between the TPTX-AT and SPTX groups in terms of persistence/recurrence of disease, incidence of transitory hypocalcemia, and temporary/permanent hypoparathyroidism. Mean calcium levels iPTH values were statistically lower among the TPTX-AT group compared with the SPTX group while remaining always in the range of normality.

Frequency and determinants of serum calcium monitoring during eldecalcitol therapy in patients with osteoporosis

INTRODUCTION

Eldecalcitol (ELD) is an active vitamin D3 analog (AVD) commonly used to treat osteoporosis in Japan. Although routine monitoring of serum calcium levels during ELD therapy is recommended, little is known about the actual frequency and determinants of monitoring.

MATERIALS AND METHODS

This was a descriptive cohort study using a Japanese electronic medical records database. We identified osteoporosis patients who initiated treatment with ELD or other AVDs (alfacalcidol and calcitriol) between April 1, 2011 and September 10, 2021. The index date for cohort entry was the first prescription date of ELD or other AVDs. The frequency of serum calcium monitoring was evaluated every 6 months. Determinants of serum calcium monitoring were identified using multivariable logistic regression models. We also calculated the incidence of hypercalcemia and the frequency of serum calcium monitoring within 6 months before hypercalcemia.

RESULTS

We identified 12,671 ELD users and 7867 other AVD users. Within 6 months after cohort entry, 45.9% of ELD users and 58.7% of other AVD users underwent serum calcium monitoring. Female sex, no use of systemic corticosteroids, moderate-to-good renal function, treatment in smaller hospitals, and treatment in orthopedic surgery departments were associated with a lower likelihood of receiving serum calcium monitoring during ELD therapy. The incidence of hypercalcemia among ELD users was 6.36 per 100 person-years, with 20.6% of cases not receiving serum calcium monitoring before hypercalcemia.

CONCLUSION

Our findings suggest that serum calcium monitoring is not given adequate attention during ELD therapy in routine clinical practice.

Clinical Experience of a Long-acting Pegylated Erythropoietin-Stimulating Agent in Pediatric Chronic Kidney Disease

OBJECTIVE

Management of anemia of chronic kidney disease (CKD) often includes subcutaneous or intravenous administration of erythropoietin-stimulating agents (ESAs). Mircera, a pegylated continuous erythropoietin receptor agonist, has a longer duration of action and requires less frequent administration than other ESAs. Pediatric experience with Mircera is limited. We retrospectively reviewed our long-term experience of Mircera in a national pediatric nephrology center.

METHODS

Patients were identified via an electronic patient record database. Data collected included demographics (sex, age, etiology of CKD, CKD stage, dialysis modality), dosing information, and laboratory data-hemoglobin (Hb), parathormone (PTH), ferritin, hematinics prior to commencing Mircera and all subsequent values associated with dose adjustments.

RESULTS

Seventy-seven patients aged 2 to 18 years, with CKD stages 2 to 5T had received at least 1 dose of Mircera, with 75 patients having sufficient data and a total of 1473 doses. No patients discontinued Mircera owing to adverse effects. One patient experienced a potential severe adverse drug reaction. Mircera was effective in improving or maintaining Hb ≥10.0 g/dL in most (58/75, 77.3%) patients. The median dose to achieve Hb ≥10.0 g/dL was 2.1 µg/kg/4 wk. Most doses (1039, 71.5%) were administered 4-weekly. The doses (161, 11.1%) that were administered 6-weekly remained efficacious. Thirty-two patients started Mircera with Hb <10.0 g/dL; 26 (81%) achieved Hb ≥10.0 g/dL within a median time of 4 months. Mircera was less effective if given every 8 weeks, or in the presence of hyperparathyroidism or hyperferritinemia.

CONCLUSION

Mircera appears safe and effective in pediatric patients with CKD.

Efficacy and safety of radiofrequency ablation for primary and secondary hyperparathyroidism: a retrospective study

There is now growing interest in the use of Ultrasound-guided radiofrequency ablation (RFA) to treat hyperparathyroidism. But the efficacy and limitations of this treatment have not been described in sufficient detail. Assessing and contrasting the effectiveness and safety of RFA in treating primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism (SHPT). This retrospective study included 57 HPT patients (48 for PHPT and 9 for SHPT) who underwent RFA between January 2017 and April 2021. The serum intact parathyroid hormone (iPTH) and calcium, hyperplastic parathyroid volume, volume reduction rate (VRR) before and after RFA, clinical success rate, symptoms, and complications were analyzed and compared. In SHPT group, bone pain (7/9, 77.8%), skin pruritus (4/9, 44.4%), and multiple hyperplastic parathyroid glands (4/9, 44.4%) were more common compared to the PHPT group. After 12 months of follow-up, the serum iPTH, calcium, and the volume of PHPT and SHPT groups had decreased by more than 60%, 10%, and 90%, respectively (P < 0.05). In the VRR, 13 glands of SHPT (72.2%) and 42 glands of PHPT (87.5%) had achieved the clinical success. In addition, the preoperative and postoperative serum iPTH were higher in the SHPT group than in the PHPT group (P < 0.05). In terms of the serum iPTH and calcium, the PHPT group had substantially higher rates of clinical success, with 42 patients (87.5%) and 46 patients (95.8%) meeting the criteria, respectively compared to 3 patients (33.3%) and 6 patients (66.7%) of SHPT group (P < 0.05). After RFA, the clinical symptoms improved in both groups. The overall incidence of complications (hoarseness and postoperative hematoma) of RFA in the two groups was 10.5% (6/57), and hoarseness (3/9, 33.3%) of SHPT group was more common than PHPT group. All the complications were resolved spontaneously within 12 months after symptomatic treatments. In the treatment of PHPT and SHPT, ultrasound-guided RFA is both successful and safe. PHPT patients have better results in restoring normal iPTH by RFA, and have no considerable difference with the SHPT patients in terms of serum calcium, the volume of the ablation area, and the VRR.

Resistin: A Potential Indicator of Aortic Stiffness in Non-Dialysis Chronic Kidney Disease Patients

Background and Objectives: In the progression and development of atherosclerosis, resistin plays a significant role. Chronic kidney disease (CKD), frequently associated with atherosclerosis, exhibits a marked increase in morbidity and mortality rates. This study set out to explore the association between aortic stiffness and serum levels of resistin in non-dialysis-dependent CKD patients ranging from stages 3 to 5. Materials and Methods: We collected fasting blood samples from 240 CKD patients across stages 3 to 5. The concentration of resistin in serum was determined using a commercially available enzyme immunoassay kit. Those patients who exhibited a carotid-femoral pulse wave velocity (cfPWV) greater than 10 m/s were identified as the aortic stiffness group. Results: Out of the 240 CKD patients, 88 (36.7%) were classified within the aortic stiffness group. This group demonstrated higher incidences of diabetes, advanced age, increased body weight, body mass index, body fat mass, systolic and diastolic blood pressure, fasting glucose, and serum resistin levels. Multivariate logistic regression analysis highlighted resistin, diabetes, and body weight as independent predictors of aortic stiffness. Additionally, body fat mass, logarithmically transformed cfPWV (log-cfPWV) values and log-triglyceride levels were independent predictors of log-resistin levels by multivariate stepwise linear regression analysis. Conclusions: In CKD patients from stages 3 to 5, a positive correlation exists between elevated serum resistin levels and cfPWV values, identifying resistin as a potential predictor of aortic stiffness.

Treatment of vitamin D deficiency in children

INTRODUCTION

Vitamin D deficiency affects from 10% to 50% in various pediatric population groups and causes life-threatening hypocalcemia in infants, crippling rickets in infants and children, and increased risk of subsequent adult metabolic and neurologic problems.

AREAS COVERED

An English language literature search of PubMed was performed since 1940 as were the authors' personal literature collections. References identified in the reviewed literature are considered.

DIAGNOSIS

The diagnosis of vitamin D deficiency is based on serum 25-hydroxyvitamin D levels. Clinical features of rickets include bone deformities and elevated alkaline phosphatase. Most children and adolescents who are biochemically vitamin D deficient do not have specific symptoms or signs of deficiency.

PREVENTION

Prevention of vitamin D deficiency is via exposure to sunshine, food and beverage fortification, and dietary supplementation.

TREATMENT

Effective treatment of vitamin D deficiency is via oral or injectable administration of vitamin D. Dosing and duration of vitamin D therapy have been described for healthy children and for children with underlying medical conditions, but recommendations vary.

EXPERT OPINION

Further investigation is needed to determine long-term non-skeletal effects of childhood vitamin D deficiency, benefits of supplementation in asymptomatic individuals with biochemical vitamin D deficiency, and appropriate screening for vitamin D deficiency in asymptomatic children and adolescents.

Parathyroidectomy and survival in a cohort of Italian dialysis patients: results of a multicenter, observational, prospective study

BACKGROUND

Severe secondary hyperparathyroidism (SHPT) is associated with mortality in end stage kidney disease (ESKD). Parathyroidectomy (PTX) becomes necessary when medical therapy fails, thus highlighting the interest to compare biochemical and clinical outcomes of patients receiving either medical treatment or surgery.

METHODS

We aimed to compare overall survival and biochemical control of hemodialysis patients with severe hyperparathyroidism, treated by surgery or medical therapy followed-up for 36 months. Inclusion criteria were age older than 18 years, renal failure requiring dialysis treatment (hemodialysis or peritoneal dialysis) and ability to sign the consent form. A control group of 418 patients treated in the same centers, who did not undergo parathyroidectomy was selected after matching for age, sex, and dialysis vintage.

RESULTS

From 82 Dialysis units in Italy, we prospectively collected data of 257 prevalent patients who underwent parathyroidectomy (age 58.2 ± 12.8 years; M/F: 44%/56%, dialysis vintage: 15.5 ± 8.4 years) and of 418 control patients who did not undergo parathyroidectomy (age 60.3 ± 14.4 years; M/F 44%/56%; dialysis vintage 11.2 ± 7.6 y). The survival rate was higher in the group that underwent parathyroidectomy (Kaplan-Meier log rank test = 0.002). Univariable analysis (HR 0.556, CI: 0.387-0.800, p = 0.002) and multivariable analysis (HR 0.671, CI:0.465-0.970, p = 0.034), identified parathyroidectomy as a protective factor of overall survival. The prevalence of patients at KDOQI targets for PTH was lower in patients who underwent parathyroidectomy compared to controls (PTX vs non-PTX: PTH < 150 pg/ml: 59% vs 21%, p = 0.001; PTH at target: 18% vs 37% p = 0.001; PTH > 300 pg/ml 23% vs 42% p = 0.001). The control group received more intensive medical treatment with higher prevalence of vitamin D (65% vs 41%, p = 0.0001), calcimimetics (34% vs 14%, p = 0.0001) and phosphate binders (77% vs 66%, p = 0.002).

CONCLUSIONS

Our data suggest that parathyroidectomy is associated with survival rate at 36 months, independently of biochemical control. Lower exposure to high PTH levels could represent an advantage in the long term.

[Applying Serum Vitamin D Metabolites in the Assessment of Renal Impairment in Diabetic Kidney Disease of Type 2 Diabetes Mellitus Patients: A Retrospective Study]

Objective

Total 25(OH)D (t-25[OH]D), a marker traditionally used in the assessment of vitamin D (VitD) in the human body, includes 25(OH)D 2, 25(OH)D 3, and C 3-epimers-25(OH)D 3(C 3-epi). In this study, we analyzed the relationship between serum VitD metabolites and renal impairment in patients with diabetic kidney disease (DKD).

Methods

We covered, in the study, 339 subjects, including 114 otherwise healthy controls (HC), 74 type 2 diabetes mellitus (DM) patients with no glomerular filtration dysfunction, and 151 DKD patients. According to the results of combined evaluation of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR), the DKD patients were further divided into four subgroups, stage 2 subgroup of patients of DM combined with stage-2 chronic kidney disease (CKD2), stage 3 subgroup of patients of DM combined with CKD3, stage 4 subgroup of patients of DM combined with CKD4, and stage 5 subgroup of patients of DM combined with CKD5. The levels of 25(OH)D 2, 25(OH)D 3, and C 3-epi were measured by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and the activity level of 25(OH) 3 (AVitD 3), t-25(OH)D concentration, 25(OH)D 2/25(OH)D 3 ratio, C 3-epi/t-25(OH)D ratio, and C 3-epi/AVitD 3 ratio were calculated.

Results

The levels of 25(OH)D 3, t-25(OH)D, and AVitD 3 were lower in the DKD group than those in the DM and HC groups (all P<0.05). C 3-epi/t-25(OH)D ratio and C 3-epi/AVitD 3 ratio were higher in the DKD group than those in the HC group (all P<0.05). The levels of 25(OH)D 3, t-25(OH)D, AVitD 3, and C 3-epi were lower in the stage 5 subgroup than those in the stage 2 and stage 3 subgroups (all P<0.05). The levels of 25(OH)D 3, t-25(OH)D, and C 3-epi were lower in the stage 4 subgroup than those in the stage 3 subgroup (all P<0.05). The 25(OH)D 3, t-25(OH)D, and AVitD 3 levels were lower in the stage 4 subgroup than those in the stage 2 subgroup (all P<0.05).

Conclusions

UPLC-MS/MS can be used to perform accurate evaluation of VitD nutritional status in DKD patients. DKD patients have decreased levels of serum t-25(OH)D, 25(OH)D 3, and AVitD 3, all of which progressively decrease along with the rise in CKD staging. The trend of C 3-epi and 25(OH)D 3 changes were not consistent.

High Dietary Phosphorus Is Associated with Increased Breast Cancer Risk in a U.S. Cohort of Middle-Aged Women

Research has shown that high amounts of dietary phosphorus that are twice the amount of the U.S. dietary reference intake of 700 mg for adults are associated with all-cause mortality, phosphate toxicity, and tumorigenesis. The present nested case-control study measured the relative risk of self-reported breast cancer associated with dietary phosphate intake over 10 annual visits in a cohort of middle-aged U.S. women from the Study of Women's Health Across the Nation. Analyzing data from food frequency questionnaires, the highest level of daily dietary phosphorus intake, >1800 mg of phosphorus, was approximately equivalent to the dietary phosphorus levels in menus promoted by the United States Department of Agriculture. After adjusting for participants' energy intake, this level of dietary phosphorus was associated with a 2.3-fold increased risk of breast cancer incidence compared to the reference dietary phosphorus level of 800 to 1000 mg, which is based on recommendations from the U.S. National Kidney Foundation, (RR: 2.30, 95% CI: 0.94-5.61, p = 0.07). Despite the lack of statistical significance, likely due to the small sample size of the cohort, the present nested case-control study's clinically significant effect size, dose-response, temporality, specificity, biological plausibility, consistency, coherence, and analogy with other research findings meet the criteria for inferred causality in observational studies, warranting further investigations. Furthermore, these findings suggest that a low-phosphate diet should be tested on patients with breast cancer.

Derivation and elimination of uremic toxins from kidney-gut axis

Uremic toxins are chemicals, organic or inorganic, that accumulate in the body fluids of individuals with acute or chronic kidney disease and impaired renal function. More than 130 uremic solutions are included in the most comprehensive reviews to date by the European Uremic Toxins Work Group, and novel investigations are ongoing to increase this number. Although approaches to remove uremic toxins have emerged, recalcitrant toxins that injure the human body remain a difficult problem. Herein, we review the derivation and elimination of uremic toxins, outline kidney-gut axis function and relative toxin removal methods, and elucidate promising approaches to effectively remove toxins.

Pre-operative Cinacalcet Administration Reduces Immediate Post-operative Hypocalcemia Following Total Parathyroidectomy in Severe Renal Hyperparathyroidism

BACKGROUND

In severe renal hyperparathyroidism (RHPT), whether administrating Cinacalcet before total parathyroidectomy can reduce post-operative hypocalcemia remains unclear. We compared post-operative calcium kinetics between those who took Cinacalcet before surgery (Group I) and those who did not (Group II).

METHODS

Patients with severe RHPT (defined by PTH ≥ 100 pmol/L) who underwent total parathyroidectomy between 2012 and 2022 were analyzed. Standardized peri-operative protocol of calcium and vitamin D supplementation was followed. Blood tests were performed twice daily in the immediate post-operative period. Severe hypocalcemia was defined as serum albumin-adjusted calcium < 2.00 mmol/L.

RESULTS

Among 159 patients who underwent parathyroidectomy, 82 patients were eligible for analysis (Group I, n = 27; Group II, n = 55). Demographics and PTH levels before Cinacalcet administration were comparable (Group I: 169 ± 49 pmol/L vs Group II: 154 ± 45, p = 0.209). Group I had significantly lower pre-operative PTH (77 ± 60 pmol/L vs 154 ± 45, p < 0.001), higher post-operative calcium (p < 0.05), and lower rate of severe hypocalcemia (33.3% vs 60.0%, p = 0.023). Longer duration of Cinacalcet use correlated with higher post-operative calcium levels (p < 0.05). Cinacalcet use for > 1 year resulted in fewer severe post-operative hypocalcemia than non-users (p = 0.022, OR 0.242, 95% CI 0.068-0.859). Higher pre-operative ALP independently correlated with severe post-operative hypocalcemia (OR 3.01, 95% CI 1.17-7.77, p = 0.022).

CONCLUSION

In severe RHPT, Cinacalcet led to significant drop in pre-operative PTH, higher post-operative calcium levels, and less frequent severe hypocalcemia. Longer duration of Cinacalcet use correlated with higher post-operative calcium levels, and the use of Cinacalcet for > 1 year reduced severe post-operative hypocalcemia.

The Potential Influence of Uremic Toxins on the Homeostasis of Bones and Muscles in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) often experience a high accumulation of protein-bound uremic toxins (PBUTs), specifically indoxyl sulfate (IS) and p-cresyl sulfate (pCS). In the early stages of CKD, the buildup of PBUTs inhibits bone and muscle function. As CKD progresses, elevated PBUT levels further hinder bone turnover and exacerbate muscle wasting. In the late stage of CKD, hyperparathyroidism worsens PBUT-induced muscle damage but can improve low bone turnover. PBUTs play a significant role in reducing both the quantity and quality of bone by affecting osteoblast and osteoclast lineage. IS, in particular, interferes with osteoblastogenesis by activating aryl hydrocarbon receptor (AhR) signaling, which reduces the expression of Runx2 and impedes osteoblast differentiation. High PBUT levels can also reduce calcitriol production, increase the expression of Wnt antagonists (SOST, DKK1), and decrease klotho expression, all of which contribute to low bone turnover disorders. Furthermore, PBUT accumulation leads to continuous muscle protein breakdown through the excessive production of reactive oxygen species (ROS) and inflammatory cytokines. Interactions between muscles and bones, mediated by various factors released from individual tissues, play a crucial role in the mutual modulation of bone and muscle in CKD. Exercise and nutritional therapy have the potential to yield favorable outcomes. Understanding the underlying mechanisms of bone and muscle loss in CKD can aid in developing new therapies for musculoskeletal diseases, particularly those related to bone loss and muscle wasting.

Salt-Sensitive Hypertension: Mediation by Salt-Induced Hypervolemia and Phosphate-Induced Vascular Calcification

Preventing hypertension by restricting dietary salt intake, sodium chloride, is well established in public health policy, but a pathophysiological mechanism has yet to explain the controversial clinical finding that some individuals have a greater risk of hypertension from exposure to salt intake, termed salt-sensitive hypertension. The present perspective paper synthesizes interdisciplinary findings from the research literature and offers novel insights proposing that the pathogenesis of salt-sensitive hypertension is mediated by interaction of salt-induced hypervolemia and phosphate-induced vascular calcification. Arterial stiffness and blood pressure increase as calcification in the vascular media layer reduces arterial elasticity, preventing arteries from expanding to accommodate extracellular fluid overload in hypervolemia related to salt intake. Furthermore, phosphate has been found to be a direct inducer of vascular calcification. Reduction of dietary phosphate may help reduce salt-sensitive hypertension by lowering the prevalence and progression of vascular calcification. Further research should investigate the correlation of vascular calcification with salt-sensitive hypertension, and public health recommendations to prevent hypertension should encourage reductions of both sodium-induced hypervolemia and phosphate-induced vascular calcification.

Patiromer Treatment in Patients With CKD, Hyperkalemia, and Hyperphosphatemia: A Post Hoc Analysis of 3 Clinical Trials

RATIONALE & OBJECTIVE

Patients with chronic kidney disease (CKD), hyperkalemia (serum potassium [sK+]>5.0 mEq/L), and hyperphosphatemia experience poor clinical outcomes. Patiromer, a potassium binder that uses calcium as the exchange ion, may also reduce serum phosphorus (sP). We characterized the effect of patiromer on sP in patients with CKD, hyperkalemia, and hyperphosphatemia.

STUDY DESIGN

A post hoc pooled analysis of individual-level data from the AMETHYST-DN, OPAL-HK, and TOURMALINE trials of patiromer.

SETTING & PARTICIPANTS

Patients with CKD and hyperkalemia.

EXPOSURE

Patients treated with patiromer (8.4-33.6 g/day).

OUTCOME

Mean changes from baseline in sP, sK+, serum calcium (sCa2+), and serum magnesium (sMg2+) after 2 and 4 weeks of treatment.

ANALYTICAL APPROACH

Descriptive statistics to summarize pooled data on the study outcomes from the 3 studies.

RESULTS

We included 578 patients in the analysis. Of these participants, 86 patients (14.9%) had baseline hyperphosphatemia of whom 75.6% (65 of 86) had CKD stage 4/5 and 31.1% (153 of 492) with sP≤4.5mg/dL had CKD stage 4/5. Among the patients with elevated sP and sK+at baseline, the mean±SD reduction in sP and sK+after 4 weeks of patiromer treatment was-0.62±1.09mg/dL and-0.71± 0.51 mEq/L, respectively. Additionally, the mean±SD reduction in sMg2+in these patients was -0.25±0.23mg/dL while sCa2+remained unchanged. Both sMg2+and sCa2+remained within the normal range. Patiromer was generally well tolerated, and no serious adverse events were considered related to patiromer.

LIMITATIONS

These were post hoc analyses, no placebo comparison was performed due to the design of the original studies, and the follow-up period was limited to 4 weeks.

CONCLUSIONS

Reductions in sP and sK+to the normal range were observed after 2 weeks of patiromer treatment, and the reduction was sustained during 4 weeks of treatment among patients with non-dialysis-dependent CKD, hyperkalemia, and hyperphosphatemia. Future controlled trials are needed to establish if patiromer is useful to reduce both sK+and sP in hyperkalemic patients with CKD and hyperphosphatemia.

Vitamin D Deficiency in Chronic Childhood Disorders: Importance of Screening and Prevention

Vitamin D plays a vital role in regulating calcium and phosphate metabolism and maintaining bone health. A state of prolonged or profound vitamin D deficiency (VDD) can result in rickets in children and osteomalacia in children and adults. Recent studies have demonstrated the pleiotropic action of vitamin D and identified its effects on multiple biological processes in addition to bone health. VDD is more prevalent in chronic childhood conditions such as long-standing systemic illnesses affecting the renal, liver, gastrointestinal, skin, neurologic and musculoskeletal systems. VDD superimposed on the underlying disease process and treatments that can adversely affect bone turnover can all add to the disease burden in these groups of children. The current review outlines the causes and mechanisms underlying poor bone health in certain groups of children and young people with chronic diseases with an emphasis on the proactive screening and treatment of VDD.

Recommendations of the Spanish Society of Nephrology for the management of mineral and bone metabolism disorders in patients with chronic kidney disease: 2021 (SEN-MM)

As in 2011, when the Spanish Society of Nephrology (SEN) published the Spanish adaptation to the Kidney Disease: Improving Global Outcomes (KDIGO) universal Guideline on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD), this document contains an update and an adaptation of the 2017 KDIGO guidelines to our setting. In this field, as in many other areas of nephrology, it has been impossible to irrefutably answer many questions, which remain pending. However, there is no doubt that the close relationship between the CKD-MBD/cardiovascular disease/morbidity and mortality complex and new randomised clinical trials in some areas and the development of new drugs have yielded significant advances in this field and created the need for this update. We would therefore highlight the slight divergences that we propose in the ideal objectives for biochemical abnormalities in the CKD-MBD complex compared to the KDIGO suggestions (for example, in relation to parathyroid hormone or phosphate), the role of native vitamin D and analogues in the control of secondary hyperparathyroidism and the contribution of new phosphate binders and calcimimetics. Attention should also be drawn to the adoption of important new developments in the diagnosis of bone abnormalities in patients with kidney disease and to the need to be more proactive in treating them. In any event, the current speed at which innovations are taking place, while perhaps slower than we might like, globally drives the need for more frequent updates (for example, through Nefrología al día).

Values of Donor Serum Lipids and Calcium in Predicting Graft Function after Kidney Transplantation: A Retrospective Study

OBJECTIVE

Delayed graft function (DGF) and early graft loss of renal grafts are determined by the quality of the kidneys from the deceased donor. As "non-traditional" risk factors, serum biomarkers of donors, such as lipids and electrolytes, have drawn increasing attention due to their effects on the postoperative outcomes of renal grafts. This study aimed to examine the value of these serum biomarkers for prediction of renal graft function.

METHODS

The present study consecutively collected 306 patients who underwent their first single kidney transplantation (KT) from adult deceased donors in our center from January 1, 2018 to December 31, 2019. The correlation between postoperative outcomes [DGF and abnormal serum creatinine (SCr) after 6 and 12 months] and risk factors of donors, including gender, age, body mass index (BMI), past histories, serum lipid biomarkers [cholesterol, triglyceride, high-density lipoprotein (HDL) and low-density lipoprotein (DL)], and serum electrolytes (calcium and sodium) were analyzed and evaluated.

RESULTS

(1) Donor age and pre-existing hypertension were significantly correlated with the incidence rate of DGF and high SCr level (≥2 mg/dL) at 6 and 12 months after KT (P<0.05); (2) The donor's BMI was significantly correlated with the incidence rate of DGF after KT (P<0.05); (3) For serum lipids, merely the low level of serum HDL of the donor was correlated with the reduced incidence rate of high SCr level at 12 months after KT [P<0.05, OR (95% CI): 0.425 (0.202-0.97)]; (4) The serum calcium of the donor was associated with the reduced incidence rate of high SCr level at 6 and 12 months after KT [P<0.05, OR (95% CI): 0.184 (0.045-0.747) and P<0.05, OR (95% CI): 0.114 (0.014-0.948), respectively].

CONCLUSION

The serum HDL and calcium of the donor may serve as predictive factors for the postoperative outcomes of renal grafts after KT, in addition to the donor's age, BMI and pre-existing hypertension.

Serum 25-hydroxyvitamin D as a predictive biomarker of clinical outcomes in patients with primary membranous nephropathy

Background

Primary membranous nephropathy (PMN) is an immune-related disease with increased morbidity and the most common cause of adult nephrotic syndrome (NS). The serum 25-hydroxyvitamin D [25(OH)D)], a biomarker of vitamin D (VD) status, tends to decline in patients with kidney disease. However, the relationship between 25(OH)D and PMN is still unclear. Therefore, this study aims to clarify the association between 25(OH)D and disease severity and therapy response of PMN.

Methods

A total of 490 participants diagnosed with PMN by biopsy from January 2017 to April 2022 were recruited at the First Affiliated Hospital of Nanjing Medical University. The correlations between baseline 25(OH)D and manifestations of nephrotic syndrome (NS) or seropositivity of anti-PLA2R Ab were confirmed by univariate and multivariate logistic analyses. Spearman's correlations were used to examine the associations between baseline 25(OH)D and other clinical parameters. In the follow-up cohort, Kaplan-Meier analysis was used to assess remission outcomes among groups with low, medium, and high levels of 25(OH)D. Furthermore, the independent risk factors for non-remission (NR) were explored by COX regression analysis.

Results

At baseline, 25(OH)D was negatively related to 24-h urinary protein and serum anti-PLA2R Ab. The lower level of baseline 25(OH)D was associated with an increased risk for the incidence of NS in PMN (model 2, OR 6.8, 95% CI 4.4, 10.7, P < 0.001) and seropositivity of anti-PLA2R Ab (model 2, OR 2.4, 95% CI 1.6, 3.7, P < 0.001). Furthermore, the lower level of 25(OH)D during follow-up was demonstrated as an independent risk factor for NR even after adjusting age, gender, MBP, 24 h UP, serum anti-PLA2R Ab, serum albumin, and serum C3 [25(OH)D (39.2-62.3 nmol/L): HR 4.90, 95% CI 1.02, 23.53 P = 0.047; 25(OH)D < 39.2 nmol/L: HR 17.52, 95% CI 4.04, 76.03 P < 0.001); vs. 25(OH)D ≥ 62.3 nmol/L]. The Kaplan-Meier survival analysis also demonstrated that the higher level of follow-up 25(OH)D had a higher possibility of remission than the lower one (log-rank test, P < 0.001).

Conclusion

Baseline 25(OH)D was significantly correlated with nephrotic proteinuria and seropositivity of anti-PLA2R Ab in PMN. As an independent risk factor for NR, a low level of 25(OH)D during follow-up might serve as a prognostic tool for sensitively identifying cases with a high probability of poor treatment response.

Treatment for secondary hyperparathyroidism focusing on parathyroidectomy

Secondary hyperparathyroidism (SHPT) is a major problem for patients with chronic kidney disease and can cause many complications, including osteodystrophy, fractures, and cardiovascular diseases. Treatment for SHPT has changed radically with the advent of calcimimetics; however, parathyroidectomy (PTx) remains one of the most important treatments. For successful PTx, removing all parathyroid glands (PTGs) without complications is essential to prevent persistent or recurrent SHPT. Preoperative imaging studies for the localization of PTGs, such as ultrasonography, computed tomography, and 99mTc-Sestamibi scintigraphy, and intraoperative evaluation methods to confirm the removal of all PTGs, including, intraoperative intact parathyroid hormone monitoring and frozen section diagnosis, are useful. Functional and anatomical preservation of the recurrent laryngeal nerves can be confirmed via intraoperative nerve monitoring. Total or subtotal PTx with or without transcervical thymectomy and autotransplantation can also be performed. Appropriate operative methods for PTx should be selected according to the patients' need for kidney transplantation. In the case of persistent or recurrent SHPT after the initial PTx, localization of the causative PTGs with autotransplantation is challenging as causative PTGs can exist in the neck, mediastinum, or autotransplanted areas. Additionally, the efficacy and cost-effectiveness of calcimimetics and PTx are increasingly being discussed. In this review, medical and surgical treatments for SHPT are described.

A Scoping Review of Vitamin D for Nonskeletal Health: A Framework for Evidence-Based Clinical Practice

BACKGROUND

Low serum 25-hydroxy-vitamin D [25(OH)D] levels are prevalent worldwide. Although the benefits of vitamin D supplementation have focused on skeletal disorders (eg, rickets, osteomalacia, osteoporosis), emerging evidence for nonskeletal health merits further discussion.

PURPOSE

The purpose of this review was to critically examine the vitamin D supplementation literature pertaining to nonskeletal health to help guide clinicians.

METHODS

A scoping review that included observational studies and randomized clinical trials (RCTs) was performed. Evidence from meta-analyses and individual RCTs are discussed, and controversies and future directions are considered.

FINDINGS

25(OH)D deficiency is a ubiquitous condition associated with multiple nonskeletal diseases, including cardiometabolic (heart disease, diabetes, and kidney disease), immune (HIV/AIDS and cancer), lung (from traditional chronic disorders to coronavirus disease 2019), and gut diseases. Vitamin D deficiency also affects health across the life span (children, pregnant, and elderly), mental illness, and reproduction in both men and women. In contrast, vitamin D supplementation does not necessarily improve major medical outcomes, even when low 25(OH)D levels are treated. Screening for 25(OH)D status remains an important practice, primarily for high-risk patients (eg, elderly, women with osteoporosis, people with low exposure to sunlight). It is reasonable to supplement with vitamin D to treat 25(OH)D deficiency, such that if beneficial nonskeletal health occurs, this may be considered as a coadjutant instead of the central tenet of the disease. Furthermore, optimizing dosing regimens is an important clinical consideration.

IMPLICATIONS

Although 25(OH)D deficiency is prevalent in nonskeletal diseases, there is no uniform evidence that vitamin D supplementation improves major medical outcomes, even when low 25(OH)D levels are corrected. Findings from RCTs warrant caution due to possible selection bias. Overall, vitamin D supplementation must be guided by circulating levels as a reasonable medical practice to correct 25(OH)D deficiency.

The Impact of Cholecaciferol Supplementation on Bone Mineral Density in Long-Term Kidney Transplant Recipients

Although reduced bone mineral density (BMD) is associated with a higher risk of fractures, morbidity, and mortality in kidney transplant patients (KTRs), there is no consensus on optimal treatment for the alterations of BMD in this population. This study aims at assessing the effect of cholecalciferol supplementation on BMD over a follow-up period of 2 years in a cohort of long-term KTRs. Patients with age ≥ 18 years were included and divided into two subgroups based on treatment with bisphosphonate and/or calcimimetics and/or active vitamin D sterols (KTRs-treated) or never treated with the above medications (KTRs-free). BMD was evaluated at lumbar vertebral bodies (LV) and right femoral neck (FN) with standard DEXA at the beginning and end of the study. According to World Health Organization (WHO) criteria, results were expressed as T-score and Z-score. Osteoporosis and osteopenia were defined as T score ≤ −2.5 SD and T score < −1 and >−2.5 SD, respectively. Cholecalciferol was supplemented at a dose of 25,000 IU/week over 12 weeks followed by 1500 IU/day. KTRs-free (n. 69) and KTRs-treated (n. 49) consecutive outpatients entered the study. KTRs-free were younger (p < 0.05), with a lower prevalence of diabetes (p < 0.05) and of osteopenia at FN (46.3 % vs. 61.2 %) compared to KTRs-treated. At the entry none of the study subjects had a sufficient level of cholecalciferol; Z-score and T-score at LV and FN were not different between groups. At the end of the study period, serum cholecalciferol concentration was significantly increased in both groups (p < 0.001); the KTRs-free group presented an improvement in both T-score and Z-score at LV (p < 0.05) as well as a lower prevalence of osteoporotic cases (21.7% vs. 15.9%); in contrast, no changes were recorded in KTR-treated individuals. In conclusion, supplementation with cholecalciferol ameliorated Z-score and T-score at LV in long-term KTRs who had been never treated with active or inactive vitamin D sterols, bisphosphonates, and calcimimetics. Future endeavours are needed to confirm these preliminary findings.

Vitamin D supplementation in children and young adults with persistent proteinuria secondary to glomerular disease

BACKGROUND

Vitamin D deficiency is common in glomerular disease. Supplementation may be ineffective due to ongoing urinary losses of vitamin D binding protein. We sought to determine if daily cholecalciferol supplementation would increase vitamin D concentrations in children with glomerular disease and persistent proteinuria, without adverse effects.

METHODS

Eighteen participants at least 5 years of age with primary glomerular disease and urine protein:creatinine ratio ≥ 0.5 were enrolled from four pediatric nephrology practices to receive cholecalciferol supplementation: 4,000 IU or 2,000 IU per day for serum 25 hydroxyvitamin vitamin D (25OHD) concentrations < 20 ng/mL and 20 ng/mL to < 30 ng/mL, respectively. Measures of vitamin D and mineral metabolism were obtained at baseline and weeks 6 and 12. Multivariable generalized estimating equation (GEE) regression estimated mean percent changes in serum 25OHD concentration.

RESULTS

Median baseline 25OHD was 12.8 ng/mL (IQR 9.3, 18.9) and increased to 27.8 ng/mL (20.5, 36.0) at week 6 (p < 0.001) without further significant increase at week 12. A total of 31% of participants had a level ≥ 30 ng/mL at week 12. Supplementation was stopped in two participants at week 6 for mildly elevated calcium and phosphorus, respectively, with subsequent declines in 25OHD of > 20 ng/mL. In the adjusted GEE model, 25OHD was 102% (95% CI: 64, 141) and 96% (95% CI: 51, 140) higher versus baseline at weeks 6 and 12, respectively (p < 0.001).

CONCLUSION

Cholecalciferol supplementation in vitamin D deficient children with glomerular disease and persistent proteinuria safely increases 25OHD concentration. Ideal dosing to fully replete 25OHD concentrations in this population remains unknown.

CLINICAL TRIAL

NCT01835639. A higher resolution version of the Graphical abstract is available as Supplementary information.

Target phosphate and calcium levels in patients undergoing hemodialysis: a post-hoc analysis of the LANDMARK study

BACKGROUND

It is necessary to re-examine the optimal phosphate (P) and calcium (Ca) target values in the contemporary management of chronic kidney disease-mineral and bone disorder to reduce the risks of cardiovascular events in patients receiving hemodialysis.

METHODS

We performed a post-hoc analysis of the LANDMARK study. The outcomes were defined as cardiovascular events and all-cause death. Data from 2135 patients receiving hemodialysis at risk of vascular calcification were analyzed using a time-dependent Cox proportional hazard model adjusted for background factors.

RESULTS

On the hazard ratio (HR) curve, the ranges where the lower 95% confidence interval (CI) were below the minimum of HR (= 1.00) were as follows: P = 3.5-5.5 mg/dL; albumin-adjusted Ca < 9.1 mg/dL for cardiovascular events; and P = 3.6-5.3 mg/dL; albumin-adjusted Ca < 9.1 mg/dL for all-cause mortality. In stratified analysis, the HRs for cardiovascular events in P < 3.5 mg/dL and P ≥ 5.5 mg/dL were similar to that of P = 3.5-5.5 mg/dL (P ≥ 0.05), and albumin-adjusted Ca ≥ 9.1 mg/dL had higher HR than values < 9.1 mg/dL [1.30 (95% CI 1.00-1.68; P = 0.046)]. For all-cause mortality, the HR in P < 3.6 mg/dL was higher than that in P = 3.6-5.3 mg/dL [1.76 (95% CI 1.25-2.48; P = 0.001)], while the HRs between P ≥ 5.3 mg/dL and P = 3.6-5.3 mg/dL as well as those between albumin-adjusted Ca ≥ 9.1 and < 9.1 mg/dL were not significantly different (P ≥ 0.05).

CONCLUSIONS

Managing albumin-adjusted Ca < 9.1 mg/dL may reduce the cardiovascular risk among patients undergoing hemodialysis. Hypophosphatemia < 3.6 mg/dL may be associated with mortality.

Sodium zirconium cyclosilicate and metabolic acidosis: Potential mechanisms and clinical consequences

Metabolic acidosis is frequent in chronic kidney disease (CKD) and is associated with accelerated progression of CKD, hypercatabolism, bone disease, hyperkalemia, and mortality. Clinical guidelines recommend a target serum bicarbonate ≥ 22 mmol/L, but metabolic acidosis frequently remains undiagnosed and untreated. Sodium zirconium cyclosilicate (SZC) binds potassium in the gut and is approved to treat hyperkalemia. In clinical trials with a primary endpoint of serum potassium, SZC increased serum bicarbonate, thus treating CKD-associated metabolic acidosis. The increase in serum bicarbonate was larger in patients with more severe pre-existent metabolic acidosis, was associated to decreased serum urea and was maintained for over a year of SZC therapy. SZC also decreased serum urea and increased serum bicarbonate after switching from a potassium-binding resin in normokalemic individuals. Mechanistically, these findings are consistent with SZC binding the ammonium ion (NH₄⁺) generated from urea by gut microbial urease, preventing its absorption and, thus, preventing the liver regeneration of urea and promoting the fecal excretion of H⁺. This mechanism of action may potentially result in benefits dependent on corrected metabolic acidosis (e.g., improved well-being, decreased catabolism, improved CKD mineral bone disorder, better control of serum phosphate, slower progression of CKD) and dependent on lower urea levels, such as decreased protein carbamylation. A roadmap is provided to guide research into the mechanisms and clinical consequences of the impact of SZC on serum bicarbonate and urate.

Real-World Analysis of Outcomes and Economic Burden in Patients with Chronic Kidney Disease with and without Secondary Hyperparathyroidism among a Sample of the Italian Population

This real-world analysis evaluated the clinical and economic burden of non-dialysis-dependent CKD patients with and without secondary hyperparathyroidism (sHPT) in Italy. An observational retrospective study was conducted using administrative databases containing a pool of healthcare entities covering 2.45 million health-assisted individuals. Adult patients with hospitalization discharge diagnoses for CKD stages 3, 4, and 5 were included from 1 January 2012 to 31 March 2015 and stratified using the presence/absence of sHPT. Of the 5710 patients, 3119 were CKD-only (62%) and 1915 were CKD + sHPT (38%). The groups were balanced using Propensity Score Matching (PSM). Kaplan-Meier curves revealed that progression to dialysis and cumulative mortality had a higher incidence in the CKD + sHPT versus CKD-only group in CKD stage 3 patients and the overall population. The total direct healthcare costs/patient at one-year follow-up were significantly higher in CKD + sHPT versus CKD-only patients (EUR 8593 vs. EUR 5671, p < 0.001), mostly burdened by expenses for drugs (EUR 2250 vs. EUR 1537, p < 0.001), hospitalizations (EUR 4628 vs. EUR 3479, p < 0.001), and outpatient services (EUR 1715 vs. EUR 654, p < 0.001). These findings suggest that sHPT, even at an early CKD stage, results in faster progression to dialysis, increased mortality, and higher healthcare expenditures, thus indicating that timely intervention can ameliorate the management of CKD patients affected by sHPT.

Association of Anemia with Parathyroid Hormone Levels and Other Factors in Patients with End-Stage Renal Disease Undergoing Hemodialysis: A Cross-Sectional, Real-World Data Study in Pakistan

End-stage renal disease (ESRD) patients are mostly managed with maintenance hemodialysis (MHD). ESRD patients on MHD also present with many complications, such as anemia, hyperparathyroidism, and hepatitis prevalence. This study depicts the real-world scenario of anemia among MHD and end-stage renal disease patients in the Pakistani population. A retrospective, multicentric, and real-world data analytical study was conducted at 4 dialysis centers in Pakistan. The study had a sample size of n = 342 patients on maintenance hemodialysis. The data were gathered from the medical records of patients. Data analysis was performed using STATA Version 16. Statistical significance was gauged at a 0.05 level of significance. According to our results, the mean age of the patients was 45 (±15) years. Most of the patients were male (n = 234, 68.4%), whereas 58.1% of the patients were maintained on twice-weekly hemodialysis. The most commonly reported comorbidities were hypertension and diabetes mellitus. The frequency of dialysis (P < 0.01) and comorbidities (P = 0.009) had a significant association with anemia in MHD patients. The majority of the patients had hyperparathyroidism (52%) with anemia. Upon performing binary logistic regression, multivariate analysis displayed a similar odds value for having anemia in patients with every additional month in the duration of hemodialysis (OR 1.01, P = 0.001), the odds of anemic patients having a positive antihepatitis-C antibody (OR 2.22, P = 0.013), and the odds of having anemia in patients in the age category below 45 years (OR 1.93, P = 0.013). In conclusion, the study results depict that every additional month in the duration of hemodialysis, age (<45 years), and positive anti-HCV antibody status, these variables were more likely to have anemia in our study MHD patients. While in our final multivariate model, no statistically significant association was observed between hyperparathyroidism and anemia.

Black patients are more likely to undergo parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

Prior studies have demonstrated racial disparities in the severity of secondary hyperparathyroidism among dialysis patients. Our primary objective was to study the racial and socioeconomic differences in the timing and likelihood of parathyroidectomy in patients with secondary hyperparathyroidism.

METHODS

We used the United States Renal Data System to identify 634,428 adult (age ≥18) patients who were on maintenance dialysis between 2006 and 2016 with Medicare as their primary payor. Adjusted multivariable Cox regression was performed to quantify the differences in parathyroidectomy by race.

RESULTS

Of this cohort, 27.3% (173,267) were of Black race. Compared to 15.4% of White patients, 23.1% of Black patients lived in a neighborhood that was below a predefined poverty level (P < .001). The cumulative incidence of parathyroidectomy at 10 years after dialysis initiation was 8.8% among Black patients compared to 4.3% among White patients (P < .001). On univariable analysis, Black patients were more likely to undergo parathyroidectomy (adjusted hazard ratio = 1.83; 95% confidence interval, 1.74-1.93). This association persisted after adjusting for age, sex, cause of end-stage renal disease, body mass index, comorbidities, dialysis modality, and poverty level (adjusted hazard ratio = 1.35; 95% confidence interval, 1.27-1.43). Therefore, patient characteristics and socioeconomic status explained 26% of the association between race and likelihood of parathyroidectomy.

CONCLUSION

Black patients with secondary hyperparathyroidism due to end-stage renal disease are more likely to undergo parathyroidectomy with shorter intervals between dialysis initiation and parathyroidectomy. This association is only partially explained by patient characteristics and socioeconomic factors.

Bone Disease in Chronic Kidney Disease and Kidney Transplant

Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) comprises alterations in calcium, phosphorus, parathyroid hormone (PTH), Vitamin D, and fibroblast growth factor-23 (FGF-23) metabolism, abnormalities in bone turnover, mineralization, volume, linear growth or strength, and vascular calcification leading to an increase in bone fractures and vascular disease, which ultimately result in high morbidity and mortality. The bone component of CKD-MBD, referred to as renal osteodystrophy, starts early during the course of CKD as a result of the effects of progressive reduction in kidney function which modify the tight interaction between mineral, hormonal, and other biochemical mediators of cell function that ultimately lead to bone disease. In addition, other factors, such as osteoporosis not apparently dependent on the typical pathophysiologic abnormalities resulting from altered kidney function, may accompany the different varieties of renal osteodystrophy leading to an increment in the risk of bone fracture. After kidney transplantation, these bone alterations and others directly associated or not with changes in kidney function may persist, progress or transform into a different entity due to new pathogenetic mechanisms. With time, these alterations may improve or worsen depending to a large extent on the restoration of kidney function and correction of the metabolic abnormalities developed during the course of CKD. In this paper, we review the bone lesions that occur during both CKD progression and after kidney transplant and analyze the factors involved in their pathogenesis as a means to raise awareness of their complexity and interrelationship.