KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD)

Moderate-severe aortic arch calcification and high serum alkaline phosphatase co-modify the risk of cardiovascular events and mortality among chronic hemodialysis patients

BACKGROUND

Patients with end-stage kidney disease undergoing chronic hemodialysis (HD) have an unparalleled risk of vascular calcification (VC) and high alkaline phosphatase (Alk-P) levels. However, whether VC contributed to the cardiovascular risk modified by serum Alk-P levels was not addressed in the population.

METHODS

A retrospective cohort study was conducted on chronic HD patients, between October 1 and December 31, 2018, with aortic arch calcification (AoAC) scores and serum Alk-P levels. Patients were categorized into four groups: non-to-mild AoAC/low Alk-P, non-to-mild AoAC/high Alk-P, moderate-to-severe AoAC/low Alk-P, and moderate-to-severe AoAC/high Alk-P. The Cox proportional hazard model and Kaplan-Meier analysis were used to evaluate the risks of major adverse cardiovascular effects (MACEs) and cardiovascular and all-cause mortality after multivariate adjustment.

RESULTS

Among 376 chronic HD patients recruited, 125 (33%) had non-to-mild AoAC/low Alk-P, 76 (20%) had non-to-mild AoAC/high Alk-P, 89 (24%) had moderate-to-severe AoAC/low Alk-P, and 86 (23%) had moderate-to-severe AoAC/high Alk-P. After 3 years of follow-up, patients with coexisting moderate-to-severe AoAC and high Alk-P had a higher risk of MACEs (aHR 1.76; 95% CI 1.06-2.92), and cardiovascular (aHR 2.49; 95% CI 1.21-5.11) and all-cause mortality (aHR 2.67; 95% CI 1.39-5.13) compared to those with non-to-mild AoAC/low Alk-P even after adjustments for significant clinical variables.

CONCLUSIONS

In chronic HD patients, moderate to severe AoAC co-existed with high Alk-P levels and enhanced the risk of MACEs and cardiovascular and all-cause mortality. Interventions to attenuate these risk factors simultaneously should be emphasized in this population.

Endothelial injury is one of the risk factors for the progression of vascular calcification in patients receiving maintenance dialysis

BACKGROUND

Vascular calcification is common and progressive in patients with chronic kidney disease. However, the risk factors associated with the progression of vascular calcification in patients receiving maintenance dialysis have not been fully elucidated. Here, we aimed to evaluate vascular calcification and identify the factors associated with its progression in patients receiving maintenance hemodialysis.

METHODS

This is a prospective longitudinal study that included 374 patients receiving maintenance hemodialysis. The participants received assessments of coronary artery calcification (CAC) and abdominal aortic calcification (AAC), as measured by computed tomography. After the baseline investigation, a 2 years follow-up was performed. We also detected the markers of endothelial injury [E-selectin and soluble intercellular adhesion molecule-1 (sICAM-1)]. Finally, the risk factors affecting the CAC and AAC progression were examined by multivariate logistic regression analysis.

RESULTS

Among 374 patients, the median [interquartile range (IQR)] age was 54.0 (40.0-62.0) years; 59.9% of patients were male. The median (IQR) follow-up time was 1.9 (1.8-2.0) years for all patients. By the end of 2-year follow-up, progression of vascular calcification (including CAC and AAC) was observed in 58.0% of patients. Further, compared with the patients without progression of vascular calcification, the endothelial injury (including E-selectin and sICAM-1) of patients with progression of vascular calcification was markedly enhanced. Moreover, after adjustment for the confounders, endothelial injury was a risk factor for the progression of vascular calcification.

CONCLUSION

The present study indicated that endothelial injury is one of the risk factors for the progression of vascular calcification in patients receiving maintenance hemodialysis.

Characteristics and prognostic values of abdominal aortic branches calcification in hemodialysis patients

BACKGROUND

Vascular calcification is highly prevalent and associated with mortality in hemodialysis patients. However, extreme splanchnic arterial calcification in calciphylaxis with poor prognosis raises questions regarding the reliability of previous vascular calcification scoring methods. Therefore, this study aimed to examine the distribution characteristics of abdominal aortic branch calcification and identify a more reliable predictor of mortality in hemodialysis patients.

METHODS

The cohort study included 237 hemodialysis patients. The distribution characteristics of abdominal aortic branch calcification were determined by quantifying the calcification volumes. The primary and secondary outcomes were all-cause mortality and new-onset cardiovascular events, respectively. We compared the prognostic values of abdominal aortic branch calcification and constructed a predictive nomogram model.

RESULTS

The prevalence of abdominal vascular calcification in hemodialysis patients was 95.36%, with the highest prevalence in the abdominal aorta (88.61%) and internal iliac artery (85.65%). During a median follow-up period of 3.92 years, 137 patients died. Internal iliac artery and mesenteric artery calcification showed the greatest predictive values for mortality. Internal iliac artery calcification and serum albumin level were independently associated with mortality in hemodialysis patients (p < .001). The nomogram model constructed with internal iliac artery calcification, serum albumin level, age, and comorbid cardiovascular disease was well discriminative, calibrated, and clinically applicable for predicting 3-year survival.

CONCLUSION

Abdominal aortic branch calcification, particularly internal iliac artery calcification, is a preferable prognostic predictor than abdominal aorta or coronary artery calcification in hemodialysis patients.

Quantification and clinical performance of serum parathyroid hormone 1-84 via immunocapture coupled to LC-MS/MS in chronic renal failure

Accurate measurement of serum parathyroid hormone (PTH) is crucial for diagnosing and managing endocrine and osteological diseases. Conventional immunoassay methods struggle with cross reactivity issues between full-length PTH and truncated fragments or post-translationally modified forms. Both the standardization of PTH assays and the peptide's stability are concerning. This study addresses these issues by establishing an immunocapture coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to precisely quantify PTH1-84. PTH1-84 was isolated from one mL serum samples by immunocapture on a polystyrene bead and eluted from matrix, then quantitated by LC-MS/MS. The results from 268 serum samples were compared to an intact PTH immunoassay. The assay's linear range was 5.0-1000.0 pg/mL. The intra-assay coefficients of variation (CVs) ranged from 3.2 % to 6.8 %, and the inter-assay CVs ranged from 4.6 % to 9.5 %. The extraction efficiencies were 98.0 %-100.5 %, with no significant matrix effects observed after internal standard correction. The correlation coefficient between LC-MS/MS and immunoassay was 0.989, but the bias between the methods was substantial. Nevertheless, the immunocapture purification coupled LC-MS/MS method offers a promising approach for accurate PTH measurement.

Secondary hyperparathyroidism due to chronic kidney disease and access to clinical treatment and parathyroidectomy in Brazil: a nationwide survey

INTRODUCTION

Chronic kidney disease (CKD) may lead to secondary hyperparathyroidism (SHP) and its treatment is based on the control of hyperphosphatemia, hypocalcemia, and serum parathormone hormone levels (PTH) levels. Despite the advances in SHP treatment, therapeutic failure is frequent and CKD patients on dialysis require parathyroidectomy (PTx).

AIM

To update the 2011 survey, estimate the current prevalence of SHP in Brazilian dialysis centers, verify access to drugs, and identify obstacles to performing PTx.

METHODS

A questionnaire was sent to active dialysis facilities. The results were compiled and statistically compared (p < 0.05).

RESULTS

A total of 114 facilities successfully responded to the questionnaire, most of them in the Southeast region. Approximately 9% of the individuals (23,535) had serum PTH levels measurements above 1,000 pg/mL (10.7% were reported in the 2011 survey). A considerable number of the reported difficulties indicated limited availability of pivotal medications for SHP management and the associated complications. Of note, only 2.7% of the individuals were submitted to PTx. For those with PTx indication, the waiting time for the procedure was over two years in 28% of the cases. The main barriers to performing PTx were reported to be the long waiting time for PTx, the shortage of head and neck surgeons, and the lack of ward beds for hospital admissions.

CONCLUSION

Some aspects have improved since 2011. However, SHP remains highly prevalent in Brazil, and a significant number of individuals do not have access to PTx or experience long waiting times for this surgical procedure while facing substantial difficulties in obtaining clinical treatment.

Synbiotics as a novel therapeutic approach for hyperphosphatemia and hyperparathyroidism in chronic kidney disease rats

Hyperphosphatemia and secondary hyperparathyroidism (SHPT) are the common complications found in CKD that lead to severe complications including mineral bone disease (MBD), vascular calcification (VC), and cardiovascular mortality. To mitigate hyperphosphatemia, SHPT and uremic toxemia, we supplemented cisplatin-induced CKD rats with a synbiotic composed of Lactobacillus salivarius LBR228, Bifidobacterium longum BFS309, fructo-oligosaccharide and chitosan oligosaccharide, with Lactobacillus casei as a standard probiotic control. After the 12 weeks experiment, rats supplemented with the synbiotic had lower serum phosphate, calcium-phosphorus product, serum parathyroid hormone, and indoxyl sulfate levels than untreated rats. The expression of type 1 RNA and protein expression were increased in rats treated with the synbiotics. Our result showed that synbiotic treatment alleviates hyperphosphatemia and SHPT, which are the main risks of MBD and VC. The mode of the synbiotic action is hypothesized to associate with the improvement of the tight junction and gut barrier, leading to the suppression of intestinal paracellular phosphate transport. This study demonstrated the beneficial effects of synbiotic treatment in the control of serum phosphate and parathyroid hormone in an animal model with CKD.

Purinergic receptor P2X7 regulates interleukin-1α mediated inflammation in chronic kidney disease in a reactive oxygen species-dependent manner

Onset, progression and cardiovascular outcome of chronic kidney disease (CKD) are influenced by the concomitant sterile inflammation. The pro-inflammatory cytokine family interleukin (IL)-1 is crucial in CKD with the key alarmin IL-1α playing an additional role as an adhesion molecule that facilitates immune cell tissue infiltration and consequently inflammation. Here, we investigate calcium ion and reactive oxygen species (ROS)-dependent regulation of different aspects of IL-1α-mediated inflammation. We show that human CKD monocytes exhibit altered purinergic calcium ion signatures. Monocyte IL-1α release was reduced when inhibiting P2X7, and to a lesser extent P2X4, two ATP-receptors that were found upregulated compared to monocytes from healthy people. In murine CKD models, deleting P2X7 (P2X7-/-) abolished IL-1α release but increased IL-1α surface presentation by bone marrow derived macrophages and impaired immune cell infiltration of the kidney without protecting kidney function. In contrast, immune cell infiltration into injured wild type and P2X7-/- hearts was comparable in a myocardial infarction model, independent of previous kidney injury. Both the chimeric mouse line harboring P2X7-/- immune cells in wild type recipient mice, and the inversely designed chimeric line showed less acute inflammation. However, only the chimera harboring P2X7-/- immune cells showed a striking resistance against injury-induced cardiac remodeling. Mechanistically, ROS measurements reveal P2X7-induced mitochondrial ROS as an essential factor for IL-1α release by monocytes. Our studies uncover a dual role of P2X7 in regulating IL-1α biogenesis with consequences for inflammation and inflammation-induced deleterious cardiac remodeling that may determine clinical outcomes in CKD therapies.

Chronic kidney disease-mineral and bone disorder: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

In 2017, Kidney Disease: Improving Global Outcomes (KDIGO) published a Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). Since then, new lines of evidence have been published related to evaluating disordered mineral metabolism and bone quality and turnover, identifying and inhibiting vascular calcification, targeting vitamin D levels, and regulating parathyroid hormone. For an in-depth consideration of the new insights, in October 2023, KDIGO held a Controversies Conference on CKD-MBD: Progress and Knowledge Gaps Toward Personalizing Care. Participants concluded that the recommendations in the 2017 CKD-MBD guideline remained largely consistent with the available evidence. However, the framework of the 2017 Guideline, with 3 major sections-biochemical abnormalities in mineral metabolism; bone disease; and vascular calcification-may no longer best reflect currently available evidence related to diagnosis and treatment. Instead, future guideline efforts could consider mineral homeostasis and deranged endocrine systems in adults within a context of 2 clinical syndromes: CKD-associated osteoporosis, encompassing increased fracture risk in patients with CKD; and CKD-associated cardiovascular disease, including vascular calcification and structural abnormalities, such as valvular calcification and left ventricular hypertrophy. Participants emphasized that the complexity of bone and cardiovascular manifestations of CKD-MBD necessitates personalized approaches to management.

Efficacy of Alfacalcidol Versus Calcitriol in Managing Secondary Hyperparathyroidism in Patients With Chronic Kidney Disease

Background: Data comparing the efficacy of alfacalcidol to that of calcitriol in managing secondary hyperparathyroidism in patients with chronic kidney disease (CKD) is scarce. We sought to compare the efficacy of both drugs in managing hyperparathyroidism in patients with CKD. Methods: A retrospective observational cohort study conducted from January 2022 to March 2023 included adults with CKD stages 3 to 5 (non-dialysis) who received alfacalcidol for 3 months followed by calcitriol for another 3 months. Assessments were done at baseline and after 3 months of each treatment. The primary outcome was iPTH suppression, and the secondary outcome was total serum calcium levels. Results: A total of 70 patients were included, with 34 (48.6%) being male. The cohort's mean age was 65.5 ± 15 years. CKD stage 3 comprised 47.1% of the sample. The median dose of alfacalcidol was 0.5 (0.25-0.8) µg compared to 0.5 (0.25-0.5) µg for calcitriol (P = .001). Alfacalcidol did not significantly suppress iPTH levels, with median values of 13.31 (8.23-24.4) pg/mL at baseline and 12.5 (8.86-24.7) pg/mL after 3 months (P = .937). In contrast, calcitriol significantly reduced iPTH levels from 12.5 (8.86-24.7) pg/mL to 10.7 (5.7-19) pg/mL (P = .017). Additionally, alfacalcidol did not significantly increase calcium levels, while calcitriol did. Throughout the study period, albumin values, the follow-up times, and the use of phosphate binders or non-active vitamin D remained consistent for each drug. The multivariate Generalized Estimating Equations indicated that baseline iPTH [B = 0.041, 95% CI (0.03- 0.05); P < .001], calcitriol [B = -0.278, 95% CI (-0.5 to -0.06); P = .014], daily dose of the study drug [B = -0.45, 95% CI (-0.7 to -0.2); P < .001], and baseline phosphorus level [B = 0.354, 95% CI (0.004-0.7); P = .047] were independent factors associated with iPTH suppression. Conclusion: Calcitriol, at significantly lower doses, was more effective than alfacalcidol in suppressing iPTH levels and increasing calcium levels over 3 months. A randomized controlled study is needed to confirm these findings.

The autonomic nervous system and bone health in chronic kidney disease

Besides the well-known role of hormonal factors in mineral and bone metabolism, the sympathetic nervous system participates in this regulation by inhibiting bone formation and promoting bone resorption, primarily via β-adrenergic receptors expressed on osteoblasts. Conversely, the parasympathetic system, through cholinergic signalling, inhibits osteoclast activity, promoting bone formation and maintaining skeletal homeostasis. This review presents the role of the autonomic nervous system, with particular focus on the potential role of β-blockers, especially β1-selective blockers, in modulating bone health in people with normal kidney function and those with CKD. While early studies with non-selective β-blockers like propranolol showed mixed results, recent findings in postmenopausal women suggested that β1-selective β-blockers could enhance bone density by modulating sympathetic activity. Trial emulation using large databases and eventually randomized controlled trials are needed to test the hypothesis that β-blockade can favourably impact bone disease in patients with kidney failure.

Long-Term Changes in Parameters of Bone Quality in Kidney Transplant Recipients Treated with Denosumab

Kidney transplant recipients (KTRs) have an elevated fracture risk. While dual-energy X-ray absorptiometry (DXA) is commonly used to assess areal bone mineral density (aBMD), it does not capture all aspects of bone quality. We investigated the long-term effects on bone DXA-derived indices of bone quality in KTRs treated with denosumab and untreated with denosumab. This is a retrospective study, including KTRs treated with denosumab and untreated age and sex-matched KTR controls. DXA-derived parameters, including trabecular bone score (TBS) and 3D-DXA parameters, were measured at the lumbar spine and femur at baseline and after four years. Hierarchical linear models were used to assess the between-group effect of treatment over time, also adjusting for site-specific aBMDs. We enrolled 23 KTRs treated with denosumab and 23 KTR denosumab-untreated KTRs. Significant between-group differences over time in favor of the denosumab group were observed for TBS (0.843, 95%CI 0.439; 1.248,p < 0.001), trabecular volumetric BMD at the total hip (Tb.vBMD TH) (13.492, 95%CI 1.707; 25.278, p = 0.003), cortical volumetric BMD at the femoral neck (Ct.vBMD FN) (28.766, 95%CI 8.373; 49.158, p = 0.008), cortical surface BMD at the total hip (c.sBMD TH) (10.507, 95%CI 4.140; 16.873,p = 0.002), cortical surface at the femoral neck (c.sBMD FN) (8.795, 95%CI 2.818; 14.771, p = 0.006), and cortical thickness at the total hip (Ct.th.TH) (0.075, 95%CI 0.020; 0.130, p = 0.010). After adjusting for BMD, the differences on TBS and Ct.vBMD FN and c.sBMD FN remained significant. Denosumab treatment in KTRs was associated with better outcomes in terms of bone quality and geometry parameters, independent of changes in aBMD.

Mild Hyponatremia Is Not Associated With Degradation of Trabecular Bone Microarchitecture Despite Bone Mass Loss

CONTEXT

Hyponatremia is associated with increased risk of osteoporosis and fractures. The impact of hyponatremia on noninvasive indices of bone quality, however, is unknown.

OBJECTIVE

To evaluate whether trabecular bone microarchitecture, assessed noninvasively by trabecular bone score (TBS), is altered in patients with hyponatremia.

METHODS

We conducted a cross-sectional analysis of the population-based 2005-2008 cycles of the National Health and Nutrition Examination Survey, in which TBS measurement was performed. The main outcome measures were TBS values and bone mineral density (BMD) T-scores at the lumbar spine, total hip and femoral neck.

RESULTS

A total of 4204 subjects aged 50 years or older were included (4041 normonatremic, 163 hyponatremic-90.8% with mild hyponatremia). Univariate analyses did not show any difference in TBS between patients with and without hyponatremia (1.308 ± 0.145 vs 1.311 ± 0.141, P = .806). Hyponatremic subjects had lower BMD T-score at total hip (-0.70 ± 1.46 vs -0.13 ± 1.32, P < .001) and femoral neck (-1.11 ± 1.26 vs -0.72 ± 1.14, P = .004), while no difference was observed at lumbar spine (-0.27 ± 1.63 vs -0.31 ± 1.51, P = .772). After adjustment for relevant confounders, hyponatremia was confirmed as an independent predictor of lower BMD T-score at the total hip (β = -0.20, 95% confidence interval [CI]: [-0.39, -0.02], P = .029), while the significance was lost at the femoral neck (P = .308). Again, no association between hyponatremia and lumbar spine BMD (P = .236) or TBS (P = .346) was observed.

CONCLUSION

Hyponatremia, at least in mild forms, is not associated with a degradation of trabecular microarchitecture, assessed noninvasively by TBS. An independent association between hyponatremia and loss of bone mass is confirmed, particularly at the total hip.

Sarcopenia in Chronic Kidney Disease: A Narrative Review from Pathophysiology to Therapeutic Approaches

Chronic kidney disease (CKD) is a progressive condition linked to sarcopenia, a syndrome characterized by loss of skeletal muscle mass and strength, affecting a quarter of CKD patients globally. Sarcopenia has multiple paths through which it can worsen morbidity and mortality as well as decrease the quality of life in CKD, including systemic inflammation, hormonal imbalances, metabolic changes, and dysbiosis of gut microbiota. There is a regional variation in the criteria set for diagnosis, with two main groups being the European Working Group on Sarcopenia in Older People and the Asian Working Group for Sarcopenia. Management regimes such as nutritional optimization, vitamin D, exercise, correction of metabolic acidosis, and modulation of gut microbiota constitute effective intervention strategies. Emerging therapeutic options include anabolic agents, myostatin inhibitors, and anti-inflammatory treatment options. Future advances such as genomics, proteomics, and personalized medicine will open up new avenues for addressing the complex pathophysiology of sarcopenia. Hence, a comprehensive multidisciplinary approach focused on the specific needs of each patient will be vital in reducing the effects of sarcopenia and improving the situation of people with CKD.

Bone mineral density and the risk of kidney disease in patients with type 1 diabetes

AIM

To explore the association between bone disorder and the risk for progression of diabetic kidney disease (DKD) in persons with type 1 diabetes mellitus (T1DM).

METHODS

In this prospective cohort study the association between bone mineral density (BMD), bone-derived factors (sclerostin, Dickkopf-1, and osteoprotegerin (OPG)), and four outcomes were investigated: 1) progression of albuminuria; 2) decline in estimated glomerular filtration rate (eGFR) ≥30 %; 3) kidney failure (KF); and 4) a composite kidney outcome consisting of at least one of the outcomes.

RESULTS

In 318 participants (median follow-up time 5.5 years) patients with osteoporosis (BMD with T-score < -2.5) had increased risk of eGFR decline: hazard ratio (HR) 2.56 (95 % CI 1.06-6.19, p = 0.04), KF: HR 9.92 (95 % CI 1.16-84.95, p = 0.04), and the composite kidney outcome: HR 2.42 (95 % CI 1.18-4.96, p = 0.02). Patients with high OPG had increased risk of eGFR decline, KF, and the composite outcome, compared to patients with low OPG in unadjusted analysis. No bone-derived factor was associated with any outcome in adjusted analyses.

CONCLUSIONS

In patients with T1DM low BMD was associated with progression of DKD, suggesting an interaction between bone and kidney.

PTH levels and establishment of reference intervals: Impact of vitamin D and renal function

INTRODUCTION

Parathyroid hormone (PTH) and vitamin D are essential components in mineral metabolism. Our aims were to estimate the thresholds of 25-hydroxyvitamin D [25(OH)D] and estimated glomerular filtration rate (eGFR) that inhibit PTH, establish PTH reference intervals (RIs), and the stratify need based on age and gender.

MATERIALS AND METHODS

We conducted a cross-sectional study on participants older than 18 years. Segmented regressions (SR) were performed to determine the thresholds of 25(OH)D and eGFR in relation to PTH levels. Multivariate regression was used to evaluate the associations between PTH and 25(OH)D, gender, age, eGFR, and season. To establish the PTH RIs, extreme percentiles were calculated.

RESULTS

A total of 2794 subjects were analyzed (women, 77.56%). Multivariate regression indicated that age, gender, 25(OH)D, and eGFR explained PTH variation. SR demonstrated that PTH stabilized when eGFR>46.64mL/min/1.73m2, and PTH increased when 25(OH)D was <15.8ng/mL. Stratification by gender and age revealed different RIs, with women and over 70 years showing higher limits.

CONCLUSION

Our study suggests a stabilization point in PTH with an eGFR>46.64mL/min/1.73m2, indicating a significant interaction between renal function and PTH regulation. Additionally, the significant increase in PTH in individuals with 25(OH)D<15.8ng/mL emphasizes the importance of vitamin D in regulation. An association between age and PTH was also evident, particularly a substantial increase after the age of 70. Finally, we established the need to define partitioned RIs for PTH based on age and gender.

KDOQI US Commentary on the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD

The Kidney Disease Outcomes Quality Initiative (KDOQI) convened a work group to review the 2024 KDIGO (Kidney Disease: Improving Global Outcomes) guideline for the management of chronic kidney disease (CKD). The KDOQI Work Group reviewed the KDIGO guideline statements and practice points and provided perspective for implementation within the context of clinical practice in the United States. In general, the KDOQI Work Group concurs with several recommendations and practice points proposed by the KDIGO guidelines regarding CKD evaluation, risk assessment, and management options (both lifestyle and medications) for slowing CKD progression, addressing CKD-related complications, and improving cardiovascular outcomes. The KDOQI Work Group acknowledges the growing evidence base to support the use of several novel agents such as sodium/glucose cotransporter 2 inhibitors for several CKD etiologies, and glucagon-like peptide 1 receptor agonists and nonsteroidal mineralocorticoid receptor antagonists for type 2 CKD in setting of diabetes. Further, KDIGO guidelines emphasize the importance of team-based care which was also recognized by the work group as a key factor to address the growing CKD burden. In this commentary, the Work Group has also assessed and discussed various barriers and potential opportunities for implementing the recommendations put forth in the 2024 KDIGO guidelines while the scientific community continues to focus on enhancing early identification of CKD and discovering newer therapies for managing kidney disease.

Parathyroid gland volume and treatment resistance in patients with secondary hyperparathyroidism: a 4-year retrospective cohort study

Background

The role of parathyroid gland (PTG) ultrasonography in the management of secondary hyperparathyroidism after the introduction of calcimimetics remains unclear. Recent investigations have prompted renewed interest in the use of PTG ultrasonography for assessing treatment resistance to calcimimetics and determining the optimal timing for surgical intervention. This study aimed to explore the hypothesis that the PTG volume correlates with the calcimimetic dose.

Methods

We retrospectively observed outpatients undergoing haemodialysis at baseline and a 4-year follow-up. PTG volume was measured using ultrasonography between January and December 2017 and January and December 2021. We examined the association between baseline PTG volume and calcimimetic doses after 4 years.

Results

Of the 121 patients {median age 64 years [interquartile range (IQR) 54-72]}, 71 had PTG nodules on ultrasonography and the median total PTG volume was 34 mm3 (IQR 0-178). In the short dialysis vintage group, baseline parathyroid hormone levels tended to correlate with baseline calcimimetic doses; however, this trend was not observed in the extended dialysis vintage group. Baseline PTG volume correlated with the cinacalcet-equivalent calcimimetic dose (correlation coefficient 0.46; P < .001) after 4 years. The calcimimetic dose in the group with an estimated PTG volume >500 mm3 was ≈80 mg/day higher than that in the non-PTG nodule group after 4 years. In multivariate linear regression analysis, PTG volume >500 mm3 was associated with a high calcimimetic dose at 4 years in all analysis models.

Conclusions

Assessing PTG volume using ultrasonography may help predict high calcimimetic doses.

KDIGO 2025 clinical practice guideline for the evaluation, management, and treatment of autosomal dominant polycystic kidney disease (ADPKD): executive summary

The Kidney Disease: Improving Global Outcomes (KDIGO) 2025 Clinical Practice Guideline for the Evaluation, Management, and Treatment of Autosomal Dominant Polycystic Kidney Disease (ADPKD) represents the first KDIGO guideline on this subject. Its scope includes nomenclature, diagnosis, prognosis, and prevalence; kidney manifestations; chronic kidney disease (CKD) management and progression, kidney failure, and kidney replacement therapy; therapies to delay progression of kidney disease; polycystic liver disease; intracranial aneurysms and other extrarenal manifestations; lifestyle and psychosocial aspects; pregnancy and reproductive issues; pediatric issues; and approaches to the management of people with ADPKD. The guideline has been developed with patient partners, clinicians, and researchers around the world, with the goal to generate a useful resource for healthcare providers and patients by providing actionable recommendations. The development of this guideline followed an explicit process of evidence review and appraisal, based on a rigorous, formal systematic literature review. The strength of recommendations follows the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The guideline also provides practice points serving to direct clinical care or activities relating to areas for which a systematic review was not conducted. Limitations of the evidence are discussed. Research recommendations to address gaps in knowledge, and implications for policy and payment, are provided. The guideline targets a broad audience of healthcare providers, people living with ADPKD, and stakeholders involved in the various aspects of ADPKD care.

Management of Elderly Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) is highly prevalent among elderly patients, and as the global population ages, the number of elderly patients with CKD is increasing. Elderly patients require additional considerations beyond those required for their younger counterparts, such as comorbidities, frailty, and geriatric syndromes. In this review, we primarily focus on these additional considerations specific to elderly patients and discuss the assessment of CKD and its management strategies, including blood pressure and glycemic control; dyslipidemia, anemia, and electrolyte and metabolic acidosis management; and medication dosage, among others, as well as polypharmacy and nonpharmacological management. Furthermore, the concept of conservative kidney management and the practical recommendations of the Korean Society of Geriatric Nephrology for elderly patients with end-stage kidney disease requiring dialysis therapy are discussed. In particular, the aging rate in Korea is exceptionally high; therefore, it is crucial to pay more attention to the increase in elderly patients with CKD. A more palliative approach, rather than intensive treatment strategies, may be necessary for these patients. In a world with an abundance of information, shared decision-making with patients is of great importance, and it is essential to keep in mind that this holds true for elderly patients as well.

Cardiovascular Safety and Fracture Prevention Effectiveness of Denosumab Versus Oral Bisphosphonates in Patients Receiving Dialysis : A Target Trial Emulation

BACKGROUND

Dialysis patients have high rates of fracture morbidity, but evidence on optimal management strategies for osteoporosis is scarce.

OBJECTIVE

To determine the risk for cardiovascular events and fracture prevention effects with denosumab compared with oral bisphosphonates in dialysis-dependent patients.

DESIGN

An observational study that attempts to emulate a target trial.

SETTING

A Japanese administrative claims database (April 2014 to October 2022).

PATIENTS

Adults aged 50 years or older who have initiated denosumab or oral bisphosphonates for osteoporosis in dialysis-dependent patients.

MEASUREMENTS

The safety outcome was major adverse cardiac events (MACE). The effectiveness outcome was a composite of all fractures. Follow-up was 3 years.

RESULTS

A total of 1032 patients were identified (658 denosumab users and 374 oral bisphosphonate users). Overall average age was 74.5 years, and 62.9% were women. The weighted 3-year risk difference for MACE was 8.2% (95% CI, -0.2% to 16.7%), with a weighted 3-year risk ratio of 1.36 (CI, 0.99 to 1.87). The weighted 3-year risk difference for composite fractures was -5.3% (CI, -11.3% to -0.6%), and the weighted 3-year risk ratio was 0.55 (CI, 0.28 to 0.93).

LIMITATIONS

Lack of clinical data on kidney or osteoporosis disease severity and cardiovascular or other metabolic risk with residual confounding. Safety outcomes did not include kidney end points.

CONCLUSION

It was estimated that, compared with oral bisphosphonates, denosumab lowered the risk for fractures by 45% and increased the risk for MACE by 36%. The estimates, however, are imprecise and need to be confirmed in future studies.

PRIMARY FUNDING SOURCE

None.

FT4 is a novel indicator for risk assessment of severe hypocalcemia following parathyroidectomy

OBJECTIVE

To analyze the risk factors associated with the development of severe hypocalcemia (SH) in patients who have undergone parathyroidectomy (PTX).

METHODS

This research involved patients with chronic kidney disease-secondary hyperparathyroidism who underwent PTX between June 1, 2021, and May 31, 2023. SH was characterized by a serum total calcium (tCa) level below 1.8 mmol/L. This study aimed to analyze differences in preoperative laboratory findings and clinical manifestations between patients with and without SH. Logistic regression analysis was used to identify potential risk factors associated with the development of SH.

RESULTS

The incidence of SH was 23% (n = 176). Significant differences were observed in free thyroxine (FT4), free triiodothyronine, alanine aminotransferase, osteocalcin, tCa, alkaline phosphatase (ALP), C-terminal cross-linked telopeptide of type I collagen, and parathyroid hormone between the SH and non-SH groups. The three independent risk factors for SH were tCa [odds ratio (OR) 0.063, 95% confidence interval (95% CI) 0.006-0.663], ALP (OR 1.003, 95% CI 1.001-1.005), and FT4 (OR 0.439, 95%CI 0.310-0.621). The area under the curve, sensitivity, specificity, and overall accuracy of this model were 0.904 (95% CI 0.856-0.952), 46.3%(95% CI 32.0%-61.3%), 94.8% (95% CI 89.7%-97.5%), and 83.5% (95% CI 77.3%-88.3%), respectively.

CONCLUSION

The preoperative level of FT4 plays a crucial role in predicting the risk of SH after PTX. The combined FT4-ALP-tCa model demonstrates the ability to predict SH risk, providing valuable insights for customizing calcium supplementation strategies and improving clinical decision-making.

Etelcalcetide: What we know eight years since its approval

INTRODUCTION AND OBJECTIVES

The impact of etelcalcetide on patients with chronic kidney disease (CKD) and secondary hyperparathyroidism (SHPT) has been studied since its introduction in 2016/2017. However, only a handful of studies reported clinically relevant outcomes. This narrative review aims to summarize the published data about etelcalcetide, focusing on biochemical, cardiovascular (CV) and bone endpoints, as well as adverse effects and all-cause mortality.

MATERIALS AND METHODS

A literature review of the use of etelcalcetide in hemodialysis patients with SHPT was conducted. Several sources were used, such as PubMed, Google Scholar and Cochrane Library.

RESULTS

Regarding bone and mineral metabolism, etelcalcetide is effective in reducing serum levels of parathormone (PTH), calcium, phosphate and fibroblast growth factor 23 (FGF23). Preliminary data have highlighted its role in reducing bone turnover and improving mineralization and preservation of bone structure, indicating a possible positive impact on renal osteodystrophy. From a CV perspective, etelcalcetide is associated with a significant reduction in left ventricular hypertrophy. In addition, etelcalcetide reduces FGF23 and increases sclerostin serum levels. This data suggests a possible CV beneficial effect.

CONCLUSIONS

Etelcalcetide is effective in controlling SHPT. Promising data is available for some bone and surrogate cardiovascular endpoints, suggesting a possible beneficial effect. There is a lack of studies specifically designed to evaluate its role in reducing fractures, CV and all-cause mortality.

Practice patterns on the management of secondary hyperparathyroidism in the United States: Results from a modified Delphi panel

BACKGROUND

Secondary hyperparathyroidism (SHPT) is common in patients with chronic kidney disease (CKD). Many recommendations in the Kidney Disease Improving Global Outcomes (KDIGO) CKD-mineral and bone disorder guidelines are supported by modest evidence and predate the approval of newer agents. Therefore, an expert panel defined consensus SHPT practice patterns in the United States with real-world context from the nephrology community.

METHODS

Ten US healthcare providers and one patient participated in a modified Delphi method comprising three phases. Consensus was determined via iterative responses to a questionnaire based on the 2009 and 2017 KDIGO guidelines and published literature on the identification, evaluation, monitoring, and interventional strategies for patients with SHPT. The threshold for consensus was 66% agreement.

RESULTS

Panelists generally agreed with KDIGO recommendations, with some differences. Consensus was reached on 42/105 (40%), 95/105 (90.5%), and 105/105 (100%) questions after phases 1, 2, and 3, respectively. Panelists unanimously agreed that SHPT treatment is often started late. There was a preference for serum phosphate level <4.6 mg/dL, and consensus to maintain serum calcium levels <9.5 mg/dL. There was unanimous agreement for vitamin D analogues as first-line options in patients not on dialysis with severe, progressive SHPT and unanimous preference for intravenous calcimimetic, etelcalcetide, in appropriate in-center dialysis patients. Factors such as formularies, dialysis center protocols, and insurance were recognized to influence therapeutic strategies.

CONCLUSIONS

Expert consensus was reached on SHPT management, further defining therapeutic strategies and medication use and emphasizing need for treatment early. Despite evidence-based treatment preferences supported by clinical experience, factors other than scientific evidence influence decision making, particularly with medications.

Cost-effectiveness analysis of three surgical approaches for parathyroidectomy in secondary hyperparathyroidism patients

Background

There are three main surgical treatment options for secondary hyperparathyroidism (SHPT): subtotal parathyroidectomy (sPTX), total parathyroidectomy with auto-transplantation (tPTX+AT), and total parathyroidectomy (tPTX). However, a debate regarding which of these surgical methods is optimal has been ongoing. Aim of this study is to compare medical costs and final outcomes associated with the three surgical approaches for the entire treatment duration, aiming to identify the most cost-effective surgical method.

Methods

Based on previous research data from domestic and international studies, as well as data from on-site surveys, TreeAge Pro 2022 software was used to construct a Markov model for the surgical treatment of SHPT patients. The model was run using data from the 2022 registered population of end-stage renal disease dialysis patients in China (1 million) as baseline cohort. Main indicators for this analysis are total cost, quality-adjusted life years, and incremental cost-effectiveness ratio (ICER). The study period is 10 years post-surgery, with a discount rate of 5% per year. Uncertainty in the model was assessed using one-way sensitivity analysis and probabilistic sensitivity analysis (PSA).

Results

The costs incurred by SHPT patients undergoing sPTX, tPTX, and tPTX+AT within 10 years post-surgery are $7042.54, $9983.00, and $11435.60, respectively, with total utilities generated being 13.23 QALYs, 18.76 QALYs, and 18.69 QALYs. Compared to sPTX, the incremental costs and incremental effects of tPTX and tPTX+AT are $2,924.71 and $4,456.66, with 5.53 QALYs and 5.46 QALYs, respectively. The ICER for tPTX and tPTX+AT groups are $532.13/QALY and $805.10/QALY, respectively, which are well below our set willingness-to-pay (WTP) threshold. Sensitivity analysis results indicate that varying any parameter within a certain range over the given time interval will not cause the ICER to exceed the WTP threshold and will not reverse the primary analysis results.

Conclusion

In the Chinese healthcare system, tPTX is considered the most cost-effective treatment for refractory hyperparathyroidism, when compared to tPTX+AT and sPTX.

The Use of Bone Biomarkers, Imaging Tools, and Genetic Tests in the Diagnosis of Rare Bone Disorders

Rare bone diseases are clinically and genetically heterogenous. Despite those differences, the underlying pathophysiology is not infrequently different. Several of these diseases are characterized by abnormal bone metabolism and turnover with subsequent abnormalities in markers of bone turnover, rendering them useful adjuncts in the diagnostic process. As most rare bone diseases are inherited, genetic testing for implicated pathogenic variants, where known, is another relevant tool that can aid in diagnosis. While some skeletal disorders can be localized or monostotic, others can involve multiple skeletal sites and warrant imaging tools to localize them and determine the severity of disease and/or presence of complications as well as to assess bone quality and the potential risk of fractures. Rare bone disorders pose a great challenge in their diagnosis, ultimately resulting in delayed diagnosis, higher risk of complications and a poor quality of life in affected individuals. In this review we discuss the biochemical and radiological tools that can be utilized to diagnose selected orphan bone disorders, the clinical utility and limitations of these diagnostic tools, and areas where future research is warranted.

Biomimetic wrinkled prebiotic microspheres with enhanced intestinal retention for hyperphosphatemia and vascular calcification

It is urgent for patients with chronic kidney disease (CKD) to develop a robust and facile therapy for effective control of serum phosphate and reasonable regulation of gut microbiota, which are aiming to prevent cardiovascular calcification and reduce cardiovascular complications. Here, bioinspired by intestinal microstructures, we developed biomimetic wrinkled prebiotic-containing microspheres with enhanced intestinal retention and absorption for reducing hyperphosphatemia and vascular calcification of CKD model rats. The resultant CSM@5 microspheres exhibited favorable phosphate binding capacity in vitro and could effectively reduce serum concentration of phosphorous in vivo. Through increasing the beneficial bacteria and decreasing the harmful bacteria in the intestinal tract, these prebiotic microspheres can modulate intestinal microbiota and then ameliorate vascular calcification notably. This feasible and robust approach may offer a potential and effective strategy for the treatment of hyperphosphatemia of CKD and prevention of its cardiovascular complications.

Evaluation of Bone Mineral Metabolism in Pre-Dialysis Chronic Kidney Disease: Quantitative Computed Tomography vs. Dual-Energy Absorptiometry and Correlation with Bone Turnover Markers

Background and Objectives: Bone and mineral disease (BMD) is a prevalent complication of advanced chronic kidney disease (CKD). The risk of fractures can be assessed via dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT). This study aims to evaluate the effectiveness of two imaging modalities in identifying bone mineral status in individuals with pre-dialysis chronic renal disease and to assess their correlation with bone turnover markers. Materials and Methods: This controlled cross-sectional study, conducted at a single center from 2019 to 2022, assessed two groups of individuals aged 18 to 50. The patient cohort consisted of individuals with stage 4-5 chronic kidney disease, whereas the control cohort consisted of healthy participants. The participants' bone and mineral status was evaluated using both QCT and DXA methods. Diagnostic measurements of the lumbar spine and femoral neck, obtained using DXA and QCT, were compared. Z-scores were utilized to evaluate low bone mineral density, with low Z-scores identified in either lumbar spine or femoral neck measures being seen as indicative of low bone mineral density. Results: Data from 38 participants (patient group: 18; control group: 20) who underwent QCT and/or DXA were evaluated. Thirty-three subjects were assessed using both QCT and DXA (patient group: 14; control group: 19). The median age of the patient cohort was 44 (range: 22-50), whereas the median age of the control cohort was 42 (range: 27-48) (p = 0.72). Women constituted 33% of the patient cohort and 50% of the control cohort (p = 0.23). In the patient cohort, low bone mineral density was detected in four individuals (28%) through QCT, and in just two patients (14%) through DXA. Compared to DXA, QCT identified a higher number of cases of low bone mineral density in the CKD cohort; however, no statistically significant difference was observed (p = 0.06). In addition, our study found that TRACP5b had a strong negative correlation with the DXA L1-L4 Z-score. Conclusions: This study revealed that QCT may be more sensitive than DXA for detecting low bone density in pre-dialysis CKD patients. Additionally, DXA may overestimate lumbar spine BMD in this population, and the strong negative correlation between TRACP5b levels and the DXA L1-L4 Z-score highlights the potential role of biochemical markers in assessing bone status in CKD.

The effects of type 1 and type 2 diabetes mellitus on bone health in chronic kidney disease

Fracture is an under-recognized but common complication of diabetes mellitus, with an incidence approaching twofold in type 2 diabetes mellitus (T2DM) and up to sevenfold in type 1 diabetes mellitus (T1DM) compared with that in the general population. Both T1DM and T2DM induce chronic hyperglycaemia, leading to the accumulation of advanced glycosylation end products that affect osteoblast function, increased collagen crosslinking and a senescence phenotype promoting inflammation. Together with an increased incidence of microvascular disease and an increased risk of vitamin D deficiency, these factors reduce bone quality, thereby increasing bone fragility. In T1DM, reduced anabolic stimuli as well as the presence of autoimmune conditions might also contribute to reduced bone mass and increased fragility. Diabetes mellitus is the most common cause of kidney failure, and fracture risk is exacerbated when chronic kidney disease (CKD)-related mineral and bone disorders are superimposed on diabetic changes. Microvascular pathology, cortical thinning and trabecular deterioration are particularly prominent in patients with T1DM and CKD, who suffer more fragility fractures than do other patients with CKD. This Review explores the pathophysiology of bone fragility in patients with diabetes mellitus and CKD and discusses techniques to predict fracture and pharmacotherapy that might reduce fracture risk.

Energy Expenditure in Chronic Kidney Disease: Affecting Factors and Evaluation Methods

Chronic kidney disease (CKD) is a chronic health problem whose prevalence is increasing. Nutrition and nutrition-related factors, one of the modifiable risk factors for CKD, are of primary importance. The key to planning optimal nutritional therapy is accurately determining energy requirements and total energy expenditure. Many health problems can accompany CKD, such as protein-energy malnutrition, sarcopenia, etc, and increase the mortality rate. This study aims to present the specific factors affecting energy expenditure specific to CKD in line with the current literature, to discuss the methods used to determine energy expenditure, and to examine these methods according to groups receiving and not receiving renal replacement therapy (hemodialysis, peritoneal dialysis, and renal transplantation).

The comparison of serum bone-turnover markers in different stage of chronic kidney disease and the associated impact of intradialytic cycling in patients with end-stage renal disease

INTRODUCTION

Bone turnover markers reflected the bone remodeling process and bone health in clinical studies. Studies on variation of bone remodeling markers in different stage CKD were scant, and this study investigated the role of bedside intradialytic cycling in altering concentrations of bone-remodeling markers in patients with end-stage renal disease (ESRD).

MATERIALS AND METHODS

Participants were segmented into four groups: a group with eGFR >60 ml/min/1.73 m2, a chronic kidney disease group with eGFR 15-60 mL/min/1.73 m2), an ESRD group with an exercise intervention, and an ESRD group with standard care. Comparison of bone turnover markers was performed among groups. The intervention consisting of 12 weeks of intradialytic cycling was performed during dialysis. The variation of bone-remodeling markers was compared between the ESRD with exercise along with the ESRD with standard care after 12-week monitoring.

RESULTS

Bone-formative marker levels (bone-specific alkaline phosphatase and procollagen type 1 amino-terminal propeptide, P1NP) were higher in ESRD patients than in non-ESRD patients and were correlated with indoxyl sulfate and intact parathyroid hormone concentrations (p < 0.05). Postexercise concentrations of tartrate-resistant acid phosphatase-5b (p = 0.003) and N-terminal telopeptide-1 (p = 0.001) had increased in the ESRD patients after 12 weeks of bedside cycling. Bone-formative marker concentration was not altered in the exercise group after cycling.

CONCLUSION

Bone-formative marker concentrations increased with the severity of chronic kidney disease. Bone formative markers concentration increased along with CKD severity. We demonstrated the bone resorptive markers tartrate-resistant acid phosphatase-5b and N-terminal telopeptide-1 increased after intradialytic cycling in ESRD patients.

Secondary hyperoxaluria: Cause and consequence of chronic kidney disease

Secondary hyperoxaluria is a metabolic disorder characterized by an increase in urinary oxalate excretion. The etiology may arise from an increase in the intake of oxalate or its precursors, decreased elimination at the digestive level, or heightened renal excretion. Recently, the role of the SLC26A6 transporter in the etiopathogenesis of this disease has been identified. This transporter is active at both the intestinal and renal levels, and its mechanism of action is disrupted during systemic inflammation and metabolic syndrome, which could explain the rising incidence of secondary hyperoxaluria in recent decades. Treatment includes hygienic dietary measures, and medications aimed at reducing intestinal absorption by increasing fecal excretion. Different immunomodulatory drugs, microbiome modifiers and SGLT2 inhibitors could constitute new therapeutic targets. Currently, specific treatments for secondary hyperoxaluria are lacking, making early diagnosis and preventive measures against kidney failure the main therapeutic strategies.

Chronic kidney disease and menopausal health: An EMAS clinical guide

Kidney diseases are related to the aging process. Ovarian senescence and the loss of estrogen's renoprotective effects are directly associated with a decline in renal function and indirectly with an accumulation of cardiometabolic risk factors. The latter can predispose to the development of chronic kidney disease (CKD). Conversely, CKD diagnosed during reproductive life adversely affects ovarian function.

AIM

To set out an individualized approach to menopause management in women with CKD.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

SUMMARY RECOMMENDATIONS

Menopause hormone therapy can be given to women with CKD. The regimen should be selected on the basis of patient preference and the individual's cardiovascular risk. The dose of hormonal and non-hormonal preparations should be adjusted in accordance with the patient's creatinine clearance. The management of a postmenopausal woman with CKD should focus on lifestyle advice as well as regular monitoring of the main cardiovascular risk factors and evaluation of bone mineral density. Tailored multidisciplinary advice should be given to women with comorbidities such as diabetes, dyslipidemia, and hypertension. Management of osteoporosis should be based on the severity of the CKD.

A comparative study of epidemiological characteristics, treatment outcomes, and mortality among patients undergoing hemodialysis by health insurance types: data from the Korean Renal Data System

BACKGROUND

The prevalence of end-stage renal disease (ESRD) requiring dialysis has progressively increased. Therefore, to achieve financial stability by managing the increasing numbers of patients undergoing hemodialysis (HD), a fixed-payment system was introduced in 2001 for medical aid (MA) beneficiaries receiving HD in Korea.

METHODS

We identified patients in the Korean Renal Data System that received HD between 2001 and 2017 and stratified them into the following two groups: the National Health Insurance (NHI) and MA groups. Then, we compared the two groups that differed in demographic characteristics, the treatment process and outcomes, and mortality based on health insurance type.

RESULTS

Among 52,574 patients, the number of patients aged 65 years or older, hypertension was higher in the NHI group, but diabetes was higher in the MA group. Additionally, the MA group had more weekly dialysis sessions, and expensive drugs tended to be used less frequently. Regarding treatment outcomes, including laboratory test results, the MA group achieved significantly lower goals than the NHI group (p < 0.001). Furthermore, the mortality rate per 1,000 persons was 31 and 27 in the MA and NHI groups, respectively, and the mortality rate ratio was 1.2 (95% confidence interval [CI], 1.076-1.230). Moreover, the hazard ratio for mortality was 1.39 (95% CI, 1.30-1.49, p < 0.001) after adjusting for age, sex, causes of ESRD, and comorbidities.

CONCLUSION

There were significant differences in the treatment and mortality indicators between the groups. Therefore, policy support should be strengthened to provide better medical services to MA beneficiaries undergoing HD.

Two-Way Randomized Crossover Study to Establish Pharmacodynamic Bioequivalence Between Oxylanthanum Carbonate and Lanthanum Carbonate

PURPOSE

Phosphate binders (PB) are integral to hyperphosphatemia management in patients with end-stage kidney disease. PB efficacy is adversely affected by nonadherence and limited phosphate-binding capacity relative to dietary intake. Oxylanthanum carbonate is an investigational novel nanotechnology product that combines lanthanum, which has the highest binding capacity of available PBs, with a smaller pill size that is swallowed with water rather than chewed. This study's objective was to demonstrate the pharmacodynamic equivalence of orally administered oxylanthanum carbonate to lanthanum carbonate (LC) in healthy subjects.

METHODS

In this phase one, single-center, randomized, open-label study, healthy subjects were treated with oxylanthanum carbonate swallowable tablets 1000 mg three times/day and LC chewable tablets 1000 mg three times/day in a two-way crossover design. The primary pharmacodynamic variable was the least squares mean (LSM) change in urinary phosphate excretion from baseline to the evaluation period (Days 1-4 of treatment).

FINDINGS

A total of 80 subjects were randomized and 75 received all doses. The LSM change in urinary phosphate excretion from Baseline to the Evaluation (Treatment) Period was similar for both oxylanthanum carbonate (-320.4 mg/day [90% CI: -349.7, -291.0]) and LC (-324.0 mg/day [90% CI: -353.3, -294.7]); the between-group LSM difference was 3.6 [90% CI: -37.8, 45.1] mg/day. Both drugs were well tolerated with an equal incidence of adverse events.

IMPLICATIONS

Thus, oxylanthanum carbonate was bioequivalent to LC in healthy subjects and well tolerated. Oral oxylanthanum carbonate may provide an option for patients with chronic kidney disease and hyperphosphatemia for whom chewing tablets is disliked, inconvenient, or difficult.

CLINICAL TRIAL REGISTRATION NUMBER

NCT06218290.

Cerebral white matter damage in patients with end-stage kidney disease associates with cognitive impairment

Background

Damage to brain white matter often occurs in individuals with chronic kidney disease, which might be related to their cognitive decline. This study aims to investigate tract-specific white matter damage in patients with end-stage kidney disease by using fixel-based analysis.

Methods

Images of 31 end-stage kidney disease patients and 16 normal controls (aged: 61.1 ± 10.4 years; 11 men) were acquired from a 1.5T magnetic resonance scanner. The patients were subsequently divided into with normal cognition (N = 17, aged: 66.9 ± 7.2 years; 10 men) and cognitive impairment (N = 14, aged: 72.4 ± 9.4 years; 7 men). Cognitive assessment, and neurologic, hematologic and biochemical samples were collected. Fixel-based analysis was used to examine the tract-specific damage within white matter. Differences between groups were evaluated through connectivity-based fixel enhancement and non-parametric permutation testing. Correlation with biomarkers was conducted through general linear model. Significance was determined with family-wise error-corrected P-value <.05.

Results

Reduced fixel-based metrics were observed in specific tract located the cerebral peduncle, internal capsule, corpus callosum, fornix and superior corona radiata in patients when compared with normal controls, indicating a reduction in fiber content. The fibers crossing the corpus callosum and the fornix/stria terminalis are particularly vulnerable sites, which can be associated with the decrease in both Mini-Mental State Examination (R2 ranged between 0.420 and 0.556) and Montreal Cognitive Assessment (R2 ranged between 0.425 and 0.509), as well as the plasma concentration of calcium (R2 ranged between 0.207 and 0.322). The plasma concentration of indoxyl sulfate was associated with the descending tracts from right posterior limb of internal capsule to cerebral peduncle (R2 ranged between 0.262 and 0.335).

Conclusions

Tract-specific white matter damage can be noticed in the patients with end-stage kidney disease, and could be associated with their cognitive decline.

Uremic Leontiasis Ossea due to Resistant Secondary Hyperparathyroidism

Background/Objective

Severe progressive overgrowth of the facial bones known as uremic leontiasis ossea (ULO) is a rare complication of resistant hyperparathyroidism in end-stage renal disease (ESRD). The objective of this report is to describe the presentation and treatment of ULO.

Case Report

A 48-year-old woman with a history of hypertension, coronary artery disease, and ESRD on hemodialysis presented with severe secondary hyperparathyroidism and calciphylaxis. She had significant changes to her face in the last 3 months leading to oropharyngeal dysphagia and difficulty articulating. Physical examination revealed bony overgrowth in her upper jaw and hard palate, widely spaced teeth, and calcinosis cutis. Her parathyroid hormone (PTH), calcium, and phosphorus levels were 5066 pg/mL (normal range, 12-88 pg/mL); 10.0 mg/dL (8.4-10.2 mg/dL); and 5.4 mg/dL (2.7-4.5 mg/dL); respectively. Using a multidisciplinary approach, she successfully underwent a 3.5-gland parathyroidectomy (immediate postoperative PTH level, 600 pg/mL). She was discharged without complication. Pathology showed hypercellular parathyroid glands with reactive changes.

Discussion

ULO, the most severe form of renal osteodystrophy, results in hypertrophy of the craniofacial skeleton. It carries the risk of significant comorbidities due to cranial nerve compression, respiratory compromise, dysarthria, and dysphagia.

Conclusion

With prolonged, uncontrolled PTH stimulation in ESRD, significant facial disfiguration with disabilities can occur. It is of utmost importance to adhere to guideline-specified PTH targets in persons with ESRD to prevent patient harm from permanent physical deformities.

Nutritional and Inflammatory Aspects of Low Parathyroid Hormone in Maintenance Hemodialysis Patients-A Longitudinal Study

BACKGROUND

Low serum parathyroid hormone (PTH) is an accepted marker for adynamic bone disease which is characterized by increased morbidity and mortality in maintenance hemodialysis (MHD) patients. In light of the known cross-sectional associations between PTH and malnutrition-inflammation syndrome, we aimed to examine the longitudinal associations between PTH with changes in nutritional and inflammatory parameters and clinical outcomes in MHD patients with low PTH.

METHODS

This historical prospective and longitudinal study analyzed a clinical database at a single hemodialysis center, containing the medical records of 459 MHD patients (mean age of 71.4 ± 12.9 years old, 171 women), treated between the years 2007-2020. Bone turnover, nutritional and inflammatory marker levels were recorded at 0, 6, 12, 18, 24, 30, and 36 months followed by a median of 24 additional months of clinical observations. According to previous use of vitamin D analogs and/or calcium-sensing receptor agonists, the study participants were divided into treatment-related and disease-related groups. A linear mixed effects model was adjusted for baseline demographics and clinical parameters.

RESULTS

Of 459 MHD patients, 81 (17.6%) had PTH lower than 150pg/mL. Among them, 30 patients had treatment-related and 51 had disease-related low PTH. At baseline, MHD patients with treatment-related low PTH had a higher rate of diabetes compared to the disease-related group. In a linear mixed effects model, increased PTH over time was associated with decreased levels of alkaline phosphatase and C-reactive protein and with increased hemoglobin and albumin, but not the geriatric nutritional risk index at 3-year follow-up. The survival rate did not differ between the groups, with the risk of hospitalizations due to fractures being higher (HR: 4.04 with 95% CI: 1.51-10.8) in the disease-related group. Statistical significance of this association was abolished after adding C-reactive protein or alkaline phosphatase to the multivariate models.

CONCLUSIONS

Low serum PTH in MHD patients behaves differently depending on its cause, with a higher risk of fractures in the disease-related group. This association is dependent on inflammation. Our results should be verified in larger epidemiological studies.

Explaining International Trends in Mortality on Hemodialysis Through Changes in Hemodialysis Practices in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

RATIONALE & OBJECTIVE

Case-mix adjusted hemodialysis mortality has decreased since 1998. Many factors that influence mortality may have contributed to this trend, and these associations may differ by continental region. We studied changes in hemodialysis facility practices over time and their potential role in mediating changes in patient survival.

STUDY DESIGN

Observational prospective cohort study.

SETTING & PARTICIPANTS

Adult hemodialysis patients treated in 500 hemodialysis facilities participating in the Dialysis Outcomes and Practice Patterns Study (DOPPS) between 1999 and 2015 in the United States, Japan, and 4 European countries: Germany, Italy, Spain, and the United Kingdom.

PREDICTORS

Four practice measures at each facility: the percentages of patients with Kt/V≥1.2, interdialytic weight gain [IDWG]<5.7%, phosphorus<6mg/dL, and using arteriovenous fistulas (AVFs).

OUTCOME

Patient survival.

ANALYTICAL APPROACH

Mediation analyses, adjusted for case mix, were conducted using 3-year study phase as the exposure and facility practice measures as potential mediators.

RESULTS

In Europe, we observed a 13% improvement in overall case-mix adjusted survival per decade. Trends in facility practice measures, especially Kt/V and phosphorus, explained 10% improvement in case-mix survival per decade, representing 77% (10% explained of 13% improvement) of the observed improvement. In Japan, 73% of the observed 12%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially Kt/V and IDWG. In the United States, 56% of the observed 47%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially AVF use and phosphorus control.

LIMITATIONS

Unmeasured changes in the characteristics of the patient population over this period may confound the observed associations.

CONCLUSIONS

The improvements in adjusted hemodialysis patient survival in Europe, Japan, and the United States from 1999 to 2015 can be largely explained by improvements in specific facility practices. Future changes in patient survival may be responsive to further evolution in the implementation of common clinical practices.

PLAIN-LANGUAGE SUMMARY

Case-mix adjusted survival of patients treated with hemodialysis has improved over the last 2 decades in the United States, Japan, and Europe. Some of this improvement can be explained by region-specific changes in 4 dialysis practices, namely increases in the proportions of patients achieving (1) Kt/V≥1.2, (2) serum phosphorus levels<6mg/dL, (3) interdialytic weight gain<5.7% of body weight, and/or (4) use of arteriovenous fistulas as vascular access, with the magnitude varying according to region-specific trends in these practices. These findings suggest that further improvement in these practice measures may be attended by further reductions in mortality among patients treated with maintenance hemodialysis.

The Effect of Denosumab on Risk for Emergently Treated Hypocalcemia by Stage of Chronic Kidney Disease : A Target Trial Emulation

BACKGROUND

There is a paucity of data on treatment of osteoporosis in patients with advanced chronic kidney disease (CKD).

OBJECTIVE

To assess the risk for emergently treated hypocalcemia with denosumab by stage of CKD and presence of CKD-mineral and bone disorder (CKD-MBD).

DESIGN

Target trial emulation.

SETTING

Medicare fee-for-service data with prescription drug coverage, 2012 to 2020.

PARTICIPANTS

Female patients aged 65 years or older initiating denosumab, oral bisphosphonates, or intravenous (IV) bisphosphonates for osteoporosis.

MEASUREMENTS

Hospital and emergency department admissions (that is, emergent care) for hypocalcemia were assessed in the first 12 treatment weeks. Inverse probability of treatment weighted cumulative incidence and weighted risk differences (RDs) were calculated.

RESULTS

A total of 361 453 patients treated with denosumab, 829 044 treated with oral bisphosphonates, and 160 413 treated with IV bisphosphonates were identified. Risk for emergently treated hypocalcemia with denosumab versus oral bisphosphonates increased with worsening CKD stage (P < 0.001), with greatest risk among dialysis-dependent (DD) patients (3.01% vs. 0.00%; RD, 3.01% [95% CI, 2.27% to 3.77%]) and non-dialysis-dependent (NDD) patients with CKD stages 4 and 5 (0.57% vs. 0.03%; RD, 0.54% [CI, 0.41% to 0.68%]). Among patients with stages 4 and 5 CKD (NDD + DD), denosumab had a greater risk for emergently treated hypocalcemia versus oral bisphosphonates in those with CKD-MBD (1.53% vs. 0.02%; RD, 1.51% [CI, 1.21% to 1.78%]) than in those without CKD-MBD (0.22% vs. 0.03%; RD, 0.19% [CI, 0.08% to 0.31%]). Denosumab also showed increased risk compared with IV bisphosphonates.

LIMITATION

Generalizability to men and non-Medicare populations.

CONCLUSION

Risk for emergently treated hypocalcemia with denosumab increased with worsening CKD stage and was highest in DD patients and those with CKD-MBD.

PRIMARY FUNDING SOURCE

U.S. Food and Drug Administration.

Estimated Proximal Tubule Fluid Phosphate Concentration and Renal Tubular Damage Biomarkers in Early Stages of Chronic Kidney Disease

OBJECTIVE

An increase in proximal tubule fluid phosphate concentration is caused by increased serum fibroblast growth factor-23 (FGF23) levels, which resulted in renal tubular damage in a mouse model of chronic kidney disease (CKD). However, few human studies have supported this concept. This study aimed to explore the association among estimated proximal tubule fluid phosphate concentration (ePTFp), serum FGF23 levels, and renal tubular damage biomarkers in middle-aged and older populations with mild decline in renal function.

METHODS

This cross-sectional study included 218 participants aged ≥45 with CKD stages G2-G4. Anthropometric measurements, blood tests, spot urine biomarkers, renal ultrasonography, cardiovascular assessment, smoking status, and medication usage were obtained in the morning in fasted states. The ePTFp was calculated using serum creatinine, urine phosphate, and creatinine concentrations. Urinary β2-microglobulin (β2-MG) and liver-type fatty acid-binding protein (L-FABP) levels were evaluated to assess renal tubular damage.

RESULTS

PTFp, serum FGF23, urinary β2-MG, and urinary L-FABP levels increased with CKD stage progression (stages G2, G3, and G4). However, serum and urine phosphate concentrations were comparable across the CKD stages. Univariate analysis revealed a stronger correlation of ePTFp with serum FGF23, urinary β2-MG, and urinary L-FABP levels than with the corresponding serum and urine phosphate concentrations. Multivariate analyses demonstrated that increased ePTFp was independently associated with elevated serum FGF23 and urinary β2-MG levels, even after adjusting for potential covariates, including the estimated glomerular filtration rate and urinary albumin-to-creatinine ratio.

CONCLUSIONS

Our results are consistent with the concept in mouse model and suggest that increased ePTFp are associated with increased serum FGF23 levels and renal tubular damage during the early stages of CKD.

Vitamin D: an important treatment for secondary hyperparathyroidism in chronic kidney disease?

Secondary hyperparathyroidism (SHPT) is one of the most common complications of chronic kidney disease (CKD). Vitamin D levels begin to decrease in the early stages of CKD, and these vitamin D-related changes play a central role in the occurrence and development of SHPT. Vitamin D-based drugs, which inhibit parathyroid hormone secretion either directly or indirectly, are commonly used to treat SHPT. However, vitamin D-based drugs can also lead to a dysregulated balance between serum calcium and phosphorus, as well as other adverse reactions. Over the past several decades, researchers have conducted in-depth studies on the pathogenesis of SHPT, developed new vitamin D-based drugs, and explored combinatory methods to improve treatment efficacy for the disease. Here, we review vitamin D metabolism, the diagnosis of vitamin D deficiency in patients with CKD, the pathogenesis of SHPT, the pharmacological effects of vitamin D drugs, and the benefits and side effects of using vitamin D to treat SHPT.

Incidence, Prediction, and Prevention of Fractures After Kidney Transplantation: A Systematic Review Protocol

Background

Kidney transplant recipients are uniquely exposed to the disordered bone metabolism associated with chronic kidney disease beginning before transplantation followed by chronic corticosteroid use after transplantation. Previous efforts to synthesize the rapidly accruing evidence regarding estimation and management of fracture risk in kidney transplant recipients are outdated and incomplete.

Objective

To synthesize the evidence informing the overall incidence, patient-specific risk prediction, and methods of prevention of fractures in patient living with a kidney transplant.

Design

Three systematic reviews will address the following questions: What is the overall incidence of skeletal fracture after kidney transplantation (review 1)? Which prediction models and individual prognostic factors predict fracture in kidney transplant recipients (review 2)? and How effective are different antifracture interventions at preventing fracture or improving surrogate markers of bone health in kidney transplant recipients (review 3)?

Setting

Cohort studies (reviews 1 and 2) and randomized trials (review 2) with a mean/median follow-up ≥12 months beginning after transplant. Review 3: randomized trials or new-user cohort studies with concurrent controls evaluating the effect of antifracture interventions including bisphosphonates, calcium supplementation, cinacalcet, denosumab, parathyroid hormone analogues, parathyroidectomy, raloxifene, romosozumab, steroid withdrawal or minimization protocols after kidney transplant, vitamin D (both active and nutritional), other antifracture interventions.

Patients

Adult kidney transplant recipients in studies published after the year 2000.

Measurements

Review 1: incidence rate or cumulative risk of fracture. Review 2: For prediction models, measures of discrimination (eg, c-statistic), calibration (calibration curves, observed:expected ratios), and net benefit (ie, from decision curve analysis); for individual prognostic factors, relative measures of association with fractures. Review 3: measures of treatment effect on fractures and on surrogate markers of bone health (eg, bone mineral density, trabecular bone score).

Methods

We searched MEDLINE, Embase, and the Cochrane Library using subject headings and keywords related to kidney transplant and fractures. Pairs of reviewers will screen records independently in duplicate to identify studies relevant to one or more of the 3 reviews and categorize each study accordingly. Single reviewers will extract data and evaluate risk of bias for each included study using one of the following tools as appropriate: the Quality of Prognostic Studies tool, the Prediction model Risk Of Bias ASsessment tool, the Risk Of Bias In Non-randomised Studies-of Interventions tool, and the Cochrane Risk of Bias 2.0 tool. A second reviewer will independently verify. We will synthesize study-level summary estimates by random-effects meta-analysis for review 1, by vote counting and random-effects meta-analysis in review 2, and by random effects pairwise and, if feasible, network meta-analysis in review 3. We will summarize findings according to latest guidance of the Grading of Recommendations Assessment, Development, and Evaluation Working Group applicable to each review.

Limitations

Reliance on published studies is susceptible to publication bias, particularly in studies of prediction (review 2) and of treatment effects (review 3).

Conclusions

This review will provide an evidence update on 3 topics of relevance to patients, clinicians, guideline developers, and researchers.

Multidisciplinary team approach for CKD-associated osteoporosis

Chronic kidney disease-mineral and bone disorder (CKD-MBD) contributes substantially to the burden of cardiovascular disease and fractures in patients with CKD. An increasing arsenal of diagnostic tools, including bone turnover markers and bone imaging, is available to support clinicians in the management of CKD-associated osteoporosis. Although not mandatory, a bone biopsy remains useful in the diagnostic workup of complex cases. In this special report, the European Renal Osteodystrophy (EUROD) initiative introduces the concept of a kidney-bone multidisciplinary team (MDT) for the diagnosis and clinical management of challenging cases of CKD-associated osteoporosis. In 2021, the EUROD initiative launched virtual clinical-pathological case conferences to discuss challenging cases of patients with CKD-associated osteoporosis, in whom a bone biopsy was useful in the diagnostic workup. Out of these, we selected four representative cases and asked a kidney-bone MDT consisting of a nephrologist, an endocrinologist and a rheumatologist to provide comments on the diagnostic and therapeutic choices. These cases covered a broad spectrum of CKD-associated osteoporosis, including bone fracture in CKD G5D, post-transplant bone disease, disturbed bone mineralization, severely suppressed bone turnover and severe hyperparathyroidism. Comments from the MDT were, in most cases, complementary to each other and additive to the presented approach in the cases. The MDT approach may thus set the stage for improved diagnostics and tailored therapies in the field of CKD-associated osteoporosis. We demonstrate the clinical utility of a kidney-bone MDT for the management of patients with CKD-MBD and recommend their establishment at local, national, and international levels.

Uric Acid Correlates with Serum Levels of Mineral Bone Metabolism and Inflammation Biomarkers in Patients with Stage 3a-5 Chronic Kidney Disease

Background and Objectives: Uric acid (UA) and the markers of mineral bone metabolism and inflammation are commonly altered in patients with chronic kidney disease (CKD) and are associated with the risk of cardiovascular complications and death. Studies point to a link between high serum UA and mineral bone homeostasis and inflammation, but controversy remains. The aim of this study was to evaluate the relationship between UA levels and mineral bone metabolism and inflammation biomarkers in a sample of Mexican patients with CKD 3a-5. Materials and Methods: This cross-sectional study included 146 Mexican patients with CKD 3a-5. In addition, 25 healthy subjects were included in the study with the aim of generating reference data for comparisons. Metabolic parameters including UA serum concentrations, mineral bone metabolism (parathormone (PTH), fibroblast growth factor 23 (FGF23), calcium, and phosphate), and inflammation (interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α)) biomarkers were measured in all of the samples and compared as a function of the estimated glomerular function rate (eGFR) or UA levels. Results: Intact PTH, FGF23, and cytokines were higher in advanced CKD stages. Patients with hyperuricemia had significantly higher values of FGF23 and TNF-α compared with those without hyperuricemia. The eGFR was found to be significantly and negatively correlated with all markers. Uric acid was significantly correlated with phosphate, iPTH, FGF23, and TNF-α, whereas iPTH was significantly correlated with FGF23, TNF-α, and FGF23. Finally, a multivariate analysis confirmed the relationship of eGFR with all the tested biomarkers, as well as other relationships of iPTH with UA and TNF-α and of FGF23 with UA and TNF-α. Conclusions: This study supports the relationship between uric acid and levels of mineral bone metabolism and inflammation biomarkers in patients with CKD at middle to advanced stages. In the follow-up of patients with CKD, monitoring and controlling UA levels through nutritional or pharmacological interventions could help in the prevention of alterations related to mineral bone metabolism.

The different serum albumin assays influence calcium status in haemodialysis patients: a comparative study against free calcium as a reference method

OBJECTIVES

Accurate assessment of calcium levels is crucial for optimal management of regular Haemodialysis (HD) patients. Different calcium adjustment equations and albumin methods; including bromocresol purple (BCP) and bromocresol green (BCG) assays are employed by laboratories, which cause considerable discrepancies between reported results. The aim of this study is to assess the influence of albumin assays on calcium status in stable haemodialysis patients against free calcium (fCa) as a gold standard test.

METHODS

103 paired serum and fCa samples were collected from a cohort of stable HD patients. Albumin levels were measured by either the BCP or BCG method, and samples were also analysed for the total calcium (T.Ca), phosphate, bicarbonate, and pH levels. The performance of BCG-based and BCP-based adjusted calcium equations was compared using Z-scores scatter plots, intraclass correlation coefficient and Cohen Kappa statistic, with fCa being the reference standard.

RESULTS

Unadjusted T.Ca achieved a 70 % overall classification agreement with fCa and identified 61 % of the "true" hypocalcaemic samples. Adjusted calcium concentrations, calculated by either BCP- or BCG-based equation, were poor predictors of fCa; with more than 50 % of the hypocalcaemic samples being misclassified as normocalcaemic. Notably, both equations misclassified the calcium status in 5 (4.9 %) patients with severe hypocalcaemia (i.e., potentially requiring calcium infusion) as mild hypocalcaemia.

CONCLUSIONS

Our study showed evidence of hidden hypocalcaemia being missed by the current practice of using adjusted calcium in HD patients. Therefore, we recommend abandoning the adjustment procedure in samples from stable HD patients in favour of fCa measurement.

Assessing the quality of CKD care using process quality indicators: A scoping review

INTRODUCTION

Assessing the quality of chronic kidney disease (CKD) management is crucial for optimal care and identifying care gaps. It is largely unknown which quality indicators have been widely used and the potential variations in the quality of CKD care. We sought to summarize process quality indicators for CKD and assess the quality of CKD care.

METHODS

We searched databases including Medline (Ovid), PubMed, Cochrane Library, Web of Science, CINAHL, and Scopus from inception to June 20, 2024. Two reviewers screened the identified records, extracted relevant data, and classified categories and themes of quality indicators.

RESULTS

We included 24 studies, extracted 30 quality indicators, and classified them into three categories with nine themes. The three categories included laboratory measures and monitoring of CKD progression and/or complications (monitoring of kidney markers, CKD mineral and bone disorder, anemia and malnutrition, electrolytes, and volume), use of guideline-recommended therapeutic agents (use of medications), and attainment of therapeutic targets (blood pressure, glycemia, and lipids). Among the frequently reported quality indicators (in five or more studies), the following have a median proportion of study participants achieving that quality indicator exceeding 50%: monitoring of kidney markers (Scr/eGFR), use of medications (ACEIs/ARBs, avoiding non-steroidal anti-inflammatory drugs (NSAIDs)), management of blood pressure (with a target of ≤140/90, or without specific targets), and monitoring for glycated hemoglobin A1c (HbA1c)). The presence of diabetes, hypertension, cardiovascular disease, or proteinuria was associated with higher achievement in indicators of monitoring of kidney markers, use of recommended medications, and management of blood pressure and glycemia.

CONCLUSION

The quality of CKD management varies with quality indicators. A more consistent and complete reporting of key quality indicators is needed for future studies assessing CKD care quality.

Novel T-cell subsets as non-invasive biomarkers of vascular damage along the predialysis stages of chronic kidney disease

Introduction

Cardiovascular disease is the major cause of premature death in chronic kidney disease (CKD) and vascular damage is often detected belatedly, usually evaluated by expensive and invasive techniques. CKD involves specific risk factors that lead to vascular calcification and atherosclerosis, where inflammation plays a critical role. However, there are few inflammation-related markers to predict vascular damage in CKD. This study aimed to investigate immune populations in pre-dialysis patients to (i) identify subset alterations, (ii) assess longitudinal changes, and (iii) evaluate their applicability as biomarkers of subclinical vascular indices.

Methods

43 pre-dialysis CKD patients in stages CKD-2 to CKD-5 and 38 controls were recruited at baseline and after 18-month follow-up. Aortic stiffness was determined by carotid-femoral pulse wave velocity (PWV) and abdominal aortic calcification was quantified by the Kauppila index on X-rays. Carotid intima-media thickness, the number of carotid plaques and adventitial neovascularization were evaluated by Superb Microvascular Imaging. Peripheral blood mononuclear cells were isolated and immune cell populations were assessed by flow cytometry: senescent T cells (CD4+CD28null), Tang (CD3+CD31+CD184+) and derived subsets, and monocyte subsets (classical, intermediate and non-classical; and ACE expression).

Results

Senescent T cells were increased in CKD. Despite Tang levels were unchanged compared to controls, this subset exhibited enhanced immunosenescence traits (CD28null and inverted CD4+CD8+ ratio) in CKD. Furthermore, Tang were negatively correlated with CKD progression. Slight alterations within monocyte subsets were observed. These findings were validated at the 18-month follow-up. Tang were correlated with several subclinical indices, and further analyses revealed an independent effect on PWV and their potential value as biomarkers. Intermediate monocytes were positively correlated with PWV.

Conclusion

Pre-dialysis CKD stages are hallmarked by alterations in immune cell populations related to vascular homeostasis, including early T-cell immunosenescence traits and a stage-dependent Tang depletion, which was independently related to vascular stiffness. All these features were replicated upon follow-up, thus providing validation toward our results. Our findings pave the ground for future studies addressing the functional contribution of these cellular mediators at the local level, assessing their potential predictive value in the long-term and implementing preventive strategies in the clinical setting.

Vitamin D status and intermediate vascular and bone outcomes in chronic kidney disease: a secondary post hoc analysis of IMPROVE-CKD

BACKGROUND AND AIMS

Cardiovascular disease is the leading cause of death in patients with chronic kidney disease (CKD) and has been associated with abnormalities of mineral metabolism and vascular calcification. Vitamin D influences parathyroid hormone values and calcium and phosphate metabolism, and may play a role in vascular function and bone health. We aimed to test our hypothesis that vitamin D deficiency is associated with arterial stiffness, aortic calcification and lower bone mineral density (BMD) in patients with CKD.

METHODS

A cross-sectional analysis was performed using baseline data from the IMpact of Phosphate Reduction On Vascular Endpoints in CKD (IMPROVE-CKD) study cohort. Clinical and laboratory parameters were compared between those with and without vitamin D deficiency, defined as 25-hydroxyvitamin D (25(OH)D) <50 nmol/L. Univariable and multivariable linear regression analyses were performed to assess associations between serum 25(OH)D levels and pulse wave velocity (PWV), augmentation index (AIx), abdominal aortic calcification (measured by the Agatston score) and lumbar spine BMD.

RESULTS

Baseline 25(OHD) values were available in 208 out of 278 IMPROVE-CKD study participants, with a mean value of 70.1 ± 30.7 nmol/L. Of these, 57 (27%) patients had vitamin D deficiency. Those with 25(OH)D deficiency were more likely to have diabetes (56% vs 38%), cardiovascular disease (54% vs 36%) and lower serum calcium (2.29 ± 0.13 vs 2.34 ± 0.13 mmol/L). On univariable and multivariable regression analyses, baseline 25(OH)D values were not associated with PWV, the AIx, Agatston score or BMD.

CONCLUSION

Baseline 25(OH)D levels were not associated with intermediate markers of vascular function and BMD in patients with CKD stages 3b and 4.