Cumulative Blood Pressure Load and Incident CKD.

RATIONALE & OBJECTIVE: The association of long-term cumulative blood pressure (BP) loads with the risk of incident chronic kidney disease (CKD) remains a matter of debate. This study aimed to investigate this association among healthy Korean adults with normal kidney function. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: We analyzed 5,221 participants without CKD in the Korean Genome and Epidemiology Study. Cumulative systolic and diastolic BP (SBP and DBP) loads were calculated as the ratios of the areas under the curve (AUC) for SBP ≥120 mmHg or ≥80 mmHg for DBP divided by the AUC for all SBP or DBP measurements during the exposure period. These AUCs were categorized into four groups: group 0 (reference), cumulative BP load of 0 and groups 1-3, tertiles of cumulative BP loads. OUTCOME: Primary endpoint was incident CKD defined as a composite of an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2 or proteinuria greater than 1+ on dipstick examination for at least two consecutive measurements ≥90 days apart. ANALYTICAL APPROACH: Multivariable Cox proportional hazards regression to estimate the independent association of cumulative BP loads with incident CKD. RESULTS: Higher cumulative SBP and DBP loads were associated with an increased risk of incident CKD (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.12-1.35 for SBP and HR 1.14, 95% CI 1.04-1.26 for DBP loads for each 1.0 unit greater load). Compared to SBP group 0, groups 2 and 3 were associated with 1.94- and 1.89-fold greater risk of incident CKD. Compared to DBP group 0, groups 2 and 3 were associated with 1.42- and 1.54-fold greater risks. These associations of high cumulative BP loads with an increased risk of incident CKD remained consistent even in subgroups not taking antihypertensive agents or without prior hypertension diagnosis. LIMITATIONS: The assessment of CKD outcomes relied on eGFR and spot urine tests. CONCLUSIONS: These findings highlight the association between high cumulative SBP and DBP loads and the occurrence of CKD, even in individuals with normal BP levels.

Understanding the Korean Dialysis Cohort for Mineral, Vascular Calcification, and Fracture (ORCHESTRA) Study: Design, Method, and Baseline Characteristics.

INTRODUCTION: End-stage renal disease (ESRD) is a growing disease worldwide, including Korea. This is an important condition that affects patient outcome. To provide optimal management for mineral disturbance, vascular calcification, and bone disease in ESRD patients, the Korean dialysis cohort for mineral, vascular calcification, and fracture (ORCHESTRA) study was conducted by enrolling Korean dialysis patients. METHODS: Sixteen university-affiliated hospitals and one Veterans' Health Service Medical Center participated in this study. This prospective cohort study enrolled approximately 900 consecutive patients on dialysis between May 2019 and January 2021. Enrolled subjects were evaluated at baseline for demographic information, laboratory tests, radiologic imaging, and bone mineral densitometry (BMD) scans. After enrollment, regular assessments of the patients were performed, and their biospecimens were collected according to the study protocol. The primary outcomes were the occurrence of major adverse cardiovascular events, invasive treatment for peripheral artery disease, and osteoporotic fractures. The secondary outcomes were hospitalization for cerebrovascular disease or progression of abdominal aortic calcification. Participants will be assessed for up to 3 years to determine whether primary or secondary outcomes occur. RESULTS: Between May 2019 and January 2021, all participating centers recruited 900 consecutive dialysis patients, including 786 undergoing hemodialysis (HD) and 114 undergoing peritoneal dialysis (PD). The mean age of the subjects was 60.4 ± 12.3 years. Males accounted for 57.7% of the total population. The mean dialysis vintage was 6.1 ± 6.0 years. The HD group was significantly older, had a longer dialysis vintage, and more comorbidities. Overall, the severity of vascular calcification was higher and the level of BMD was lower in the HD group than in the PD group. CONCLUSION: This nationwide, multicenter, prospective cohort study focused on chronic kidney disease-mineral and bone disorder and aimed to provide clinical evidence to establish optimal treatment guidelines for Asian dialysis patients.

Urinary chemokine C-X-C motif ligand 16 and endostatin as predictors of tubulointerstitial fibrosis in patients with advanced diabetic kidney disease.

BACKGROUND: Interstitial fibrosis and tubular atrophy (IFTA) is a well-recognized risk factor for poor renal outcome in patients with diabetic kidney disease (DKD). However, a noninvasive biomarker for IFTA is currently lacking. The purpose of this study was to identify urinary markers of IFTA and to determine their clinical relevance as predictors of renal prognosis. METHODS: Seventy patients with biopsy-proven isolated DKD were enrolled in this study. We measured multiple urinary inflammatory cytokines and chemokines by multiplex enzyme-linked immunosorbent assay in these patients and evaluated their association with various pathologic features and renal outcomes. RESULTS: Patients enrolled in this study exhibited advanced DKD at the time of renal biopsy, characterized by moderate to severe renal dysfunction [mean estimated glomerular filtration rate (eGFR) 36.1 mL/min/1.73 m2] and heavy proteinuria (mean urinary protein:creatinine ratio 7.8 g/g creatinine). Clinicopathologic analysis revealed that higher IFTA scores were associated with worse baseline eGFR (P < 0.001) and poor renal outcome (P = 0.002), whereas glomerular injury scores were not. Among measured urinary inflammatory markers, C-X-C motif ligand 16 (CXCL16) and endostatin showed strong correlations with IFTA scores (P = 0.001 and P < 0.001, respectively), and patients with higher levels of urinary CXCL16 and/or endostatin experienced significantly rapid renal progression compared with other patients (P < 0.001). Finally, increased urinary CXCL16 and endostatin were independent risk factors for poor renal outcome after multivariate adjustments (95% confidence interval 1.070-3.455, P = 0.029). CONCLUSIONS: Urinary CXCL16 and endostatin could reflect the degree of IFTA and serve as biomarkers of renal outcome in patients with advanced DKD.

Dialysis Care and Dialysis Funding in Asia.

Asia is the largest and most populated continent in the world, with a high burden of kidney failure. In this Policy Forum article, we explore dialysis care and dialysis funding in 17 countries in Asia, describing conditions in both developed and developing nations across the region. In 13 of the 17 countries surveyed, diabetes is the most common cause of kidney failure. Due to great variation in gross domestic product per capita across Asian countries, disparities in the provision of kidney replacement therapy (KRT) exist both within and between countries. A number of Asian nations have satisfactory access to KRT and have comprehensive KRT registries to help inform practices, but some do not, particularly among low- and low-to-middle-income countries. Given these differences, we describe the economic status, burden of kidney failure, and cost of KRT across the different modalities to both governments and patients and how changes in health policy over time affect outcomes. Emerging trends suggest that more affluent nations and those with universal health care or access to insurance have much higher prevalent dialysis and transplantation rates, while in less affluent nations, dialysis access may be limited and when available, provided less frequently than optimal. These trends are also reflected by an association between nephrologist prevalence and individual nations' incomes and a disparity in the number of nephrologists per million population and per thousand KRT patients.

New oral spherical carbon adsorbent effectively reduces serum indoxyl sulfate levels in moderate to advanced chronic kidney disease patients: a multicenter, prospective, open-label study.

BACKGROUND: Elevated levels of serum indoxyl sulfate (IS) have been linked to cardiovascular complications in patients with chronic kidney disease (CKD). Oral sorbent therapy using spherical carbons selectively attenuates IS accumulation in CKD patients. This study aimed to investigate whether oral administration of a new oral spherical carbon adsorbent (OSCA), reduces serum IS levels in moderate to severe CKD patients. METHODS: This prospective, multicenter, open-label study enrolled patients with CKD stages 3-5. Patients were prescribed OSCA for 8 weeks (6 g daily in 3 doses) in addition to standard management. Serum IS levels were measured at baseline and 4 and 8 weeks of treatment with OSCA. RESULTS: A total of 118 patients were enrolled and 87 eligible patients completed 8 weeks of study. The mean age of the study subjects was 62.8 ± 13.7 years, and 80.5% were male. Baseline levels of serum IS were negatively correlated with estimated glomerular filtration rate (eGFR) (r = - 0.406, P < 0.001) and increased with increasing CKD stages (stage 3, 0.21 ± 0.21 mg/dL; stage 4, 0.54 ± 0.52 mg/dL; stage 5, 1.15 ± 054 mg/dL; P for trend = 0.001). The patients showed significant reduction in serum total IS levels as early as 4 weeks after OSCA treatment (22.5 ± 13.9% reduction from baseline, P < 0.001) and up to 8 weeks (31.9 ± 33.7% reduction from baseline, P < 0.001). This reduction effect was noted regardless of age, kidney function, or diabetes. No severe adverse effects were reported. Gastrointestinal symptoms were the most commonly reported adverse effects. In total, 21 patients withdrew from the study, with dyspepsia due to heavy pill burden as the most common reason. The medication compliance rate was 84.7 ± 21.2% (min 9%, max 101%) for 8 weeks among those who completed the study. CONCLUSIONS: OSCA effectively reduced serum IS levels in moderate to severe CKD patients. Gastrointestinal symptoms were the most commonly reported complications, but no treatment-related severe adverse effects were reported. TRIAL REGISTRATION: Clinical Research Information Service ( KCT0001875 . 14 December 2015.).

Removal of large middle molecules via haemodialysis with medium cut-off membranes at lower blood flow rates: an observational prospective study.

BACKGROUND: Online haemodiafiltration (OL-HDF) may improve middle molecular clearance in contrast to conventional haemodialysis (HD). However, OL-HDF requires higher convective flows and cannot sufficiently remove large middle molecules. This study evaluated the efficacy of a medium cut-off (MCO) dialyser in removing large middle molecular uraemic toxins and compared it with that of conventional high-flux (HF) dialysers in HD and predilution OL-HDF. METHODS: Six clinically stable HD patients without residual renal function were investigated. Dialyser and treatment efficacies were examined during a single midweek treatment in three consecutive periods: 1) conventional HD using an HF dialyser, 2) OL-HDF using the same HF dialyser, and 3) conventional HD using an MCO dialyser. Treatment efficacy was assessed by calculating the reduction ratio (RR) for ß2-microglobulin (ß2M), myoglobin, κ and λ free light chains (FLCs), and fibroblast growth factor (FGF)-23 and measuring clearance for FLCs. RESULTS: All three treatments showed comparable RRs for urea, phosphate, creatinine, and uric acid. MCO HD showed greater RRs for myoglobin and λFLC than did HF HD and predilution OL-HDF (myoglobin: 63.1 ± 5.3% vs. 43.5 ± 8.9% and 49.8 ± 7.3%; λFLC: 43.2 ± 5.6% vs. 26.8 ± 4.4% and 33.0 ± 9.2%, respectively; P <  0.001). Conversely, predilution OL-HDF showed the greatest RR for ß2M, whereas MCO HD and HF HD showed comparable RRs for ß2M (predilution OL-HDF vs. MCO HD: 80.1 ± 4.9% vs. 72.6 ± 3.8%, P = 0.01). There was no significant difference among MCO HD, HF HD, and predilution OL-HDF in the RRs for κFLC (63.2 ± 6.0%, 53.6 ± 15.5%, and 61.5 ± 7.0%, respectively; P = 0.37), and FGF-23 (55.5 ± 20.3%, 34.6 ± 13.1%, and 35.8 ± 23.2%, respectively; P = 0.13). Notably, MCO HD showed improved clearances for FLCs when compared to HF HD or OL-HDF. CONCLUSIONS: MCO HD showed significantly greater RR of large middle molecules and achieved improved clearance for FLCs than conventional HD and OL-HDF, without the need for large convection volumes or high blood flow rates. This would pose as an advantage for elderly HD patients with poor vascular access and HD patients without access to OL-HDF. TRIAL REGISTRATION: Clinical Research Information Service (CRIS): KCT 0003009. The trial was prospectively registered on the 21 Jul 2018.

The relationship between autophagy, increased neutrophil extracellular traps formation and endothelial dysfunction in chronic kidney disease.

In chronic kidney disease (CKD), the number of circulating neutrophils are increased, and this is usually accompanied by an increased basal activation state. However, the possible association between neutrophil extracellular traps (NETs) with vascular complications has not been evaluated. We assessed the relationship between NETs, autophagy and endothelial dysfunction in maintenance hemodialysis (MHD) patients. NET formation, neutrophil elastase (NE) activities, and serum nucleosome levels were measured in MHD (n = 60) and controls (n = 20). Basal NET formation were markedly increased in MHD patient compared to controls. After PMA stimulation, MHD neutrophils showed significantly increased NETs formation response than controls. The degree of NETs was strongly associated with lower flow-mediated dilatation(%) of brachial artery even after adjustment for cardiovascular risk factors and uremic toxins. Moreover, MHD neutrophils showed increased basal autophagy activity. Interestingly, the levels of NETs were markedly augmented after autophagy inhibition, suggesting a protective role of autophagy in excessive NET formation.

Comparative efficacy and safety of gemigliptin versus linagliptin in type 2 diabetes patients with renal impairment: A 40-week extension of the GUARD randomized study.

AIMS: The long-term safety and efficacy of gemigliptin was evaluated in the present extension study after a 12-week study during a 40-week follow-up period. METHODS: The main study was a randomized, placebo-controlled, double-blinded, phase IIIb study in which 50 mg of gemigliptin (N = 66) or placebo (N = 66) was administered to patients with type 2 diabetes mellitus (T2DM) and moderate or severe renal impairment over a 12-week period. Patients with a glycated haemoglobin (HbA1c) level of 7% to 11% and an estimated glomerular filtration rate (eGFR) of 15 to 59 mL/min/1.73 m2 were enrolled in the main study. After 12 weeks, patients in the gemigliptin group continued to receive gemigliptin (N = 50), whereas patients in the placebo group were transitioned from placebo to linagliptin (N = 52). Each group received the indicated treatment over the subsequent 40-week period. A total of 102 patients consented to participate in the extension study, and 79 patients ultimately completed the study. RESULTS: The HbA1c levels of both groups were significantly reduced at week 52 compared with baseline. Specifically, the adjusted mean change ± standard error in HbA1c level in the gemigliptin and placebo/linagliptin groups was 1.00% ± 0.21% and 0.65% ± 0.22% lower at week 52 than at baseline (P < .001 and P = .003), respectively. No significant difference in the change in HbA1c level was found between the 2 groups (P = .148). Trends in fasting plasma glucose, fructosamine and glycated albumin levels in the 2 groups were similar to trends in HbA1c levels. The eGFR of both groups was also significantly lower at week 52 than at baseline, and no significant difference in change in eGFR was found between the 2 groups. In contrast, both drugs had little effect on urinary albumin excretion, although both drugs significantly reduced the urinary type IV collagen level. The overall rates of adverse events were similar between the 2 groups. CONCLUSIONS: Gemigliptin and linagliptin did not differ with respect to safety and efficacy in patients with T2DM and renal impairment. The 2 drugs had similar glucose-lowering effects, and the changes in eGFR and albuminuria were also similar. Additionally, the risk of side effects, including hypoglycaemia, was similar between the 2 groups.

Intravenous iron and erythropoiesis-stimulating agents in haemodialysis: A systematic review and meta-analysis.

AIM: Higher dosages of erythropoiesis-stimulating agents (ESAs) have been associated with adverse effects. Intravenous iron is used to optimize ESA response and reduces ESA doses in haemodialysis patients; this meta-analysis evaluates the magnitude of this effect. METHODS: A literature search was performed using MEDLINE, Embase and the Cochrane Collaboration Central Register of Clinical Trials from inception until December 2014, to identify randomized controlled trials of intravenous iron and ESA, in patients undergoing haemodialysis for end-stage kidney disease. Dosing of IV iron in concordance with the Kidney Disease Improving Global Outcomes guidelines was considered optimal iron therapy. RESULTS: Of the 28 randomized controlled trials identified, seven met the criteria for inclusion in the meta-analysis. Results of random-effects meta-analysis show a statistically significant weighted mean (95% CI) difference of -1733 [-3073, -392] units/week in ESA dose for optimal iron versus suboptimal iron. The weighted average change in ESA dose was a reduction of 23% (range -7% to -55%) attributable to appropriate dosing of intravenous iron. A comparison of intravenous iron versus oral iron/no iron (five trials) showed a greater reduction in ESA dose, although this did not reach statistical significance (weighted mean difference, 95% CI: -2,433 [-5183, 318] units/week). The weighted average change in ESA dose across the five trials was a reduction of 31% (range -8% to -55%). CONCLUSION: Significant reductions in ESA dosing may be achieved with optimal intravenous iron usage in the haemodialysis population, and suboptimal iron use may require higher ESA dosing to manage anaemia.

The relationship between hemodialysis modality and insulin resistance in non-diabetic hemodialysis patients.

BACKGROUND: Although various modalities of hemodialysis (HD) are presumed to have different effects on insulin resistance (IR), the relationship between hemodiafiltration (HDF) and IR has not been fully evaluated. METHODS: In a cross-sectional study, 82 non-diabetic HD patients were enrolled. The patients were divided into two groups according to the median homeostasis model assessment index (HOMA-IR) value of 1.685. Clinical and biochemical data were compared, and multivariate logistic regression analysis was performed to identify the independent factors associated with higher HOMA-IR. RESULTS: The higher HOMA-IR group had increased body mass index (BMI), decreased HDL cholesterol, and lower beta-2 microglobulin reduction rate (ß2-MG RR) compared to the lower HOMA-IR group. HOMA-IR was significantly correlated with ß2-MG RR. In addition, HDF patients had lower HOMA-IR levels compared with low flux hemodialysis patients. On multivariate logistic regression analysis, BMI and HDF treatment were independent factors associated with higher and lower HOMA-IR, respectively. CONCLUSION: This study suggests that HDF treatment may reduce IR in non-diabetic HD patients.

Customized Hydrogel Films for MicroRNA Super-Resolution Imaging in Liquid Biopsies.

Tissue biopsy for early diagnosis and monitoring comes with several challenges, such as its invasiveness, and issues related to tissue heterogeneity in sampling. To address these issues, researchers have proposed a noninvasive approach called liquid biopsy, which uses blood samples to detect specific noncoding RNA (microRNA, miRNA). However, the current process of isolating and amplifying miRNA can be time-consuming and yield nonspecific results. In this study, a new super-resolution imaging tool is introduced that utilizes a thin, hydrogel-based liquid view (LV) film. This film can undergo a ninefold expansion and allows the analysis of cells obtained from liquid biopsy. The potential of the LV film is validated as a tool for early diagnosis and prognosis by testing biofluids derived from a variety of diseases. This method is confirmed to accurately analyze a greater number of miRNAs with higher sensitivity in a shorter time compared to other analytical methods. These findings suggest that the LV film provides high specificity, and multiplexing in detecting small amounts of miRNAs within cells, making it suitable for 3D implementation. It is proposed that liquid biopsy with LV films can be a solution to limitations related to the invasiveness, cost, and time-consuming nature of molecular analysis.

Adiponectin-to-leptin ratio and incident chronic kidney disease: Sex and body composition-dependent association.

BACKGROUND: The association between the adiponectin-to-leptin ratio (A/L ratio) and the risk of incident chronic kidney disease (CKD) is poorly understood. This study aimed to investigate the association between A/L ratio and the risk of incident CKD and to examine whether such a relationship varied according to sex and body composition. METHODS: In this prospective community-based cohort, participants with normal kidney function were analysed (N = 5192). The association between the A/L ratio at baseline and the risk of incident CKD, defined as two or more occasions with an estimated glomerular filtration rate of <60 mL/min/m2 or proteinuria of ≥1+ on a dipstick test during the follow-up period, was evaluated using multivariable Cox proportional hazards analyses. Subgroup analyses were conducted based on sex, body mass index (BMI) and the presence of sarcopenia. RESULTS: The participants' mean age was 57.2 ± 8.3 years, and 53.2% were women. The A/L ratio was higher in men compared with women (1.5 [0.8-3.2] and 0.5 [0.3-0.9] µg/ng, P < 0.001). During a median follow-up of 9.8 [9.5-10.0] years, 417 incident CKD events occurred (8.7 per 1000 person-years). Men in the highest quartile of A/L ratio had a lower risk of incident CKD (adjusted hazard ratio [aHR], 0.57; 95% confidence interval [CI], 0.33-0.99) than those in the lowest quartile. Additionally, a 1.0 increase in A/L ratio was associated with a 12% decreased risk of incident CKD in men (aHR, 0.88; 95% CI, 0.80-0.97). However, no significant association was observed in women. In subgroup analysis stratified by BMI and the presence of sarcopenia, the association between a high A/L ratio and a reduced risk of incident CKD was consistent in men with a BMI < 23.0 kg/m2 and those with sarcopenia. However, no significant association was observed between men with a BMI ≥ 23.0 kg/m2 and those without sarcopenia. CONCLUSIONS: A high A/L ratio is an independent marker of a reduced risk of incident CKD in men, especially in those with a BMI < 23.0 kg/m2 and sarcopenia.

Capacity for the management of kidney failure in the International Society of Nephrology North and East Asia region: report from the 2023 ISN Global Kidney Health Atlas (ISN-GKHA).

Globally, there remain significant disparities in the capacity and quality of kidney care, as evidenced by the third edition of the International Society of Nephrology Global Kidney Health Atlas (ISN-GKHA). In the ISN North and East Asia region, the chronic kidney disease (CKD) burden varied widely; Taiwan had the heaviest burden of treated kidney failure (3679 per million population [pmp]) followed by Japan and South Korea. Except in Hong Kong, hemodialysis (HD) was the main dialysis modality for all other countries in the region and was much higher than the global median prevalence. Kidney transplantation services were generally available in the region, but the prevalence was much lower than that of dialysis. Most countries had public funding for kidney replacement therapy (KRT). The median prevalence of nephrologists was 28.7 pmp, higher than that of any other ISN region, with variation across countries. Home HD was available in only 17% of the countries, whereas conservative kidney management was available in 50%. All countries had official registries for dialysis and transplantation; however, only China and Japan had CKD registries. Advocacy groups for CKD, kidney failure, and KRT were uncommon throughout the region. Overall, all countries in the region had capacity for KRT, albeit with some shortages in their kidney care workforce. These data are useful for stakeholders to address gaps in kidney care and to reduce workforce shortages through increased use of multidisciplinary teams and telemedicine, policy changes to promote prevention and treatment of kidney failure, and increased advocacy for kidney disease in the region.

Atherogenic indices and risk of chronic kidney disease in metabolic derangements: Gangnam Severance Medical Cohort.

Background: The effects of atherogenic indices on kidney function remain unclear. This study evaluated the association between atherogenic indices and risk of chronic kidney disease (CKD) in adults with metabolic derangements. Methods: A total of 4,176 participants from the Gangnam Severance Medical Cohort (2006-2021), which consisted of participants who had at least one disease related to metabolic derangements including diabetes mellitus, fatty liver, and hypertension were enrolled and atherogenic indices (lipid ratios including atherogenic index of plasma [AIP]) were assessed. The study endpoint was a composite kidney outcome (estimated glomerular filtration rate [eGFR] of <60 mL/min/1.73 m2 in at least two measurements in participants with baseline eGFR of ≥60 mL/min/1.73 m2; ≥30% decrease in eGFR from baseline in participants with baseline eGFR of <60 mL/min/1.73 m2; or the initiation of dialysis or kidney transplantation). Results: During a median follow-up of 6.0 years (interquartile range, 2.5-11.0 years), 1,266 composite kidney outcomes (30.3%) occurred. The highest quartile of AIP showed a higher risk of composite kidney outcome than the lowest quartile (hazard ratio [HR], 1.31; 95% confidence interval [CI], 1.12-1.54). This association was consistent when the AIP was treated as a continuous variable (HR per 1.0 increase, 1.51; 95% CI, 1.21-1.88). However, other atherogenic indices did not show significant associations with composite kidney outcome. Adding AIP to the traditional risk model to predict composite kidney outcomes significantly improved the C-index, net reclassification index, and integrated discrimination improvement. The association between high AIP and an increased risk of composite kidney outcome was consistent regardless of subgroup. Conclusion: High AIP was associated with an increased risk of CKD in adults with metabolic derangements.

Machine learning-based 2-year risk prediction tool in immunoglobulin A nephropathy.

Background: This study aimed to develop a machine learning-based 2-year risk prediction model for early identification of patients with rapid progressive immunoglobulin A nephropathy (IgAN). We also assessed the model's performance to predict the long-term kidney-related outcome of patients. Methods: A retrospective cohort of 1,301 patients with biopsy-proven IgAN from two tertiary hospitals was used to derive and externally validate a random forest-based prediction model predicting primary outcome (30% decline in estimated glomerular filtration rate from baseline or end-stage kidney disease requiring renal replacement therapy) and secondary outcome (improvement of proteinuria) within 2 years after kidney biopsy. Results: For the 2-year prediction of primary outcomes, precision, recall, area-under-the-curve, precision-recall-curve, F1, and Brier score were 0.259, 0.875, 0.771, 0.242, 0.400, and 0.309, respectively. The values for the secondary outcome were 0.904, 0.971, 0.694, 0.903, 0.955, and 0.113, respectively. From Shapley Additive exPlanations analysis, the most informative feature identifying both outcomes was baseline proteinuria. When Kaplan-Meier analysis for 10-year kidney outcome risk was performed with three groups by predicting probabilities derived from the 2-year primary outcome prediction model (low, moderate, and high), high (hazard ratio [HR], 13.00; 95% confidence interval [CI], 9.52-17.77) and moderate (HR, 12.90; 95% CI, 9.92-16.76) groups showed higher risks compared with the low group. From the 2-year secondary outcome prediction model, low (HR, 1.66; 95% CI, 1.42-1.95) and moderate (HR, 1.42; 95% CI, 0.99-2.03) groups were at greater risk for 10-year prognosis than the high group. Conclusion: Our machine learning-based 2-year risk prediction models for the progression of IgAN showed reliable performance and effectively predicted long-term kidney outcome.

Clinical significance of neutrophil-to-lymphocyte ratio on the risk of abdominal aortic calcification and decreased bone mineral density in patients with end-stage kidney disease.

Inflammation plays a major role in the pathogenesis of chronic kidney disease (CKD), but the relationship between systemic inflammation and CKD-mineral bone disease is unclear. We aimed to investigate whether the neutrophil-to-lymphocyte ratio (NLR) is related to abdominal aortic calcification (AAC) and bone mineral density (BMD) in dialysis patients. In this cross-sectional analysis using baseline data of a multicenter cohort, a total of 759 patients were divided into three groups according to NLR level, and the associations between NLR and Kauppila AAC score (AACS) and BMD were assessed. The highest tertile NLR group had more males, alcohol consumers, higher diabetes prevalence, and higher comorbidity index than the lowest tertile NLR group. Fasting glucose and C-reactive protein levels were higher, while serum albumin, serum iron, and lipid profiles except triglycerides were lower in the highest tertile group. AACS was significantly higher in the highest tertile group than in the lowest and middle tertile groups (p = 0.017), but the mean areal BMD and T-score of the lumbar spine and femur were not different between groups. NLR level was positively correlated with AACS in all aortic wall segments except L1 and L3 anterior. In multivariable logistic regression analysis, the highest tertile NLR group was independently associated with AAC (odds ratio 2.876, 95% confidence interval 1.250-6.619, p = 0.013) but was not associated with osteoporosis in the lumbar spine and femur after adjusting for confounding factors. The NLR can be used as a potential indicator of AAC in dialysis patients.

Evaluating the Safety and effectivenesS in adult KorEaN patients treated with Tolvaptan for management of autosomal domInAnt poLycystic kidney disease (ESSENTIAL): short-term outcomes during the titration period.

BACKGROUND: Tolvaptan reduces height-adjusted total kidney volume (htTKV) and renal function decline in autosomal dominant polycystic kidney disease (ADPKD). This study was aimed at investigating the efficacy and safety of tolvaptan in Korean patients with ADPKD during the titration period. METHODS: This study is a multicenter, single-arm, open-label phase 4 study. We enrolled 108 patients with ADPKD (age, 19-50 years) with an estimated glomerular filtration rate (eGFR) of >30 mL/min/1.73 m2 and factors defined as indicative of rapid disease progression. After tolvaptan titration, we evaluated efficacy and side effects and assessed factors associated with the effects. RESULTS: After titration for 4 weeks, eGFR and htTKV decreased by 6.4 ± 7.9 mL/min/1.73 m2 and 16 ± 45 mL/m, respectively. No serious adverse drug reactions were observed during the titration period. The greatest eGFR decline was observed in the first week, with a starting tolvaptan dose of 45 mg. Multivariate linear regression for htTKV decline showed that the greater the change in urine osmolality (Uosm), the greater the decrease in htTKV (ß, 0.436; p = 0.009) in the 1D group stratified by the Mayo Clinic image classification. Higher baseline eGFR was related to a higher htTKV reduction rate in the 1E group (ß, -0.642; p = 0.009). CONCLUSION: We observed short-term effects and safety during the tolvaptan titration period. The decline of htTKV can be predicted as a short-term effect of tolvaptan by observing Uosm changes from baseline to end of titration in 1D and baseline eGFR in 1E groups.

Risk factors affecting seroconversion after influenza A/H1N1 vaccination in hemodialysis patients.

BACKGROUND: Hemodialysis (HD) patients have multiple causes of immune dysfunction and poor immune response to influenza vaccination. We investigated the antibody response rate to a pandemic H1N1/2009 influenza vaccination and clinical parameters influencing the induction of antibody responses in HD patients. METHODS: A total of 114 HD patients were vaccinated with a monovalent adjuvanted H1N1 inactivated influenza vaccine. Titers of neutralizing antibodies were evaluated by hemagglutination inhibition (HI) assay at pre- and 4 weeks after vaccination. Seroconversion was defined as either a pre-vaccination HI titer < 1:10 and a post vaccination HI titer > 1:40 or a pre-vaccination HI titer ≥ 1:10 and a minimum four-fold rise in post-vaccination HI antibody titer. Seventeen out of 114 HD patients (14.9%) tested positive for antibodies against influenza A/H1N1/2009 before vaccination. The remaining 97 baseline sero-negative patients were included in the analysis. RESULTS: Only 30 (30.9%) HD patients had seroconversion 4 weeks after vaccination. The elderly patients, those over 65 years of age, showed significantly lower seroconversion rate compared to younger HD patients (20.5% vs. 39.6%, p = 0.042). Furthermore, patients with hemoglobin values less than 10 g/dL had a significantly lower seroconversion rate compared to those with higher hemoglobin values (20.0 vs. 38.6%, p = 0.049). By multivariate logistic regression analysis, only age ≥65 years (OR = 0.336, 95% confidence interval (CI) 0.116-0.971, p = 0.044) and hemoglobin levels <10 g/dL (OR = 0.315, 95% CI 0.106-0.932, p = 0.037) were independently associated with seroconversion after vaccination. CONCLUSIONS: Our data show that HD patients, especially who are elderly with low hemoglobin levels, are at increased risk for lower seroconversion rate after influenza A/H1N1 vaccination. Further studies are needed to improve the efficacy of vaccination in these high risk patients.

Skin Sodium and Blood Pressure Regulation.

Hypertension is a major public health concern due to its high prevalence and increased risk of cardiovascular disease and mortality. Complex traits resulting from both genetic and environmental factors affect the development of hypertension. Among environmental factors, a high salt diet is an important cause for hypertension. Humans show a heterogeneous blood pressure (BP) response to sodium intake. Although the precise mechanisms for the association between salt sensitivity and hypertension have not been fully elucidated, renal sodium handling has been considered to play a pivotal role. However, this conventional view has recently been challenged in that a third compartment, namely, skin may have a role in the regulation of sodium homeostasis. Skin is comprised of a significant portion of interstitium, which is a major extracellular fluid compartment, and its complex capillary network regulates body temperature and skin perfusion. Growing evidence indicates that local regulatory action of cutaneous blood flow as well as salt and water metabolism is associated with systemic BP control. Previous experimental studies have shown that dietary salt loading resulted in nonosmotic sodium accumulation via glycosaminoglycans and lymphatics embedded in the skin that were mediated by several endogenous factors and attenuated an increase in BP. Studies in humans have also suggested that the skin serves as a buffer system for sodium storage and that skin sodium contributes to salt sensitivity and hypertension. Thus, skin sodium storage provides the possibility of being an additional buffering system in response to salt loading and concomitant BP changes in humans.

High Triglyceride-Glucose Index with Renal Hyperfiltration and Albuminuria in Young Adults: The Korea National Health and Nutrition Examination Survey (KNHANES V, VI, and VIII).

Background: High triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, is associated with an increased risk of albuminuria in adults. However, the relationship between high TyG index associated with renal hyperfiltration (RHF) and albuminuria among young adults is unclear. Methods: A total of 5420 participants aged 19−39 years were enrolled from the Korean National Health and Nutrition Examination Survey (2011−2014 and 2019) and their TyG index levels were analyzed. RHF was defined as eGFR with residuals > 90th percentile after adjusting for age, sex, weight, and height. Albuminuria was defined as urinary albumin-to-creatinine ratio ≥ 30 mg/g Cr. Logistic regression analyses were used to evaluate the association between TyG index, RHF, and albuminuria. Results: The mean age was 30.7 ± 6.0 years and 46.4% were male. The prevalence of albuminuria and RHF was higher in the higher tertiles of TyG index. In our multivariable model, high TyG index showed higher risk of albuminuria (odds ratio (OR) per 1.0 increase in TyG index, 1.56; 95% confidence interval (CI), 1.24−1.95 and OR in the highest tertile, 1.65; 95% CI, 1.08−2.52). High TyG index was associated with higher risk of RHF (OR per 1.0 increase in TyG index, 1.56; 95% CI, 1.32−1.84 and OR in the highest tertile, 1.73; 95% CI, 1.31−2.30). When participants were divided into with or without RHF, high-TyG index-associated high risk of albuminuria was only observed in those with RHF. Participants with concurrent high TyG index and RHF showed the highest risk of albuminuria. Mediation analysis showed that 54.2% of the relation between TyG index and albuminuria was mediated by RHF (95% CI of indirect effect, 0.27−0.76). Finally, incorporating TyG index into our basic model improved the predictive value for albuminuria only in participants with RHF. Conclusion: High TyG index associated with RHF was the strongest risk factor for albuminuria in this study. Early identification of high TyG index with RHF may prevent future development of CKD in relatively healthy and young adults.