Complication Of Chronic Kidney Disease Research Articles

Use of Fludrocortisone for Hyperkalemia in Chronic Kidney Disease Not Yet on Dialysis.

Hyperkalemia is a frequent and potentially lethal complication of chronic kidney disease (CKD). We retrospectively examined the potassium-lowering effect of oral fludrocortisone and its adverse effects in hyperkalemic CKD patients not yet on dialysis. Thirty-three patients (23 men and 10 women, ages 69±14 years) were included. To control hyperkalemia at the outpatient clinic, twenty-one patients (Group 1) received fludrocortisone (0.05-0.1 mg/day) without changes in angiotensin II receptor blockers (ARBs) and calcium polystyrene sulfonate (CPS), while twelve patients (Group 2) were treated with fludrocortisone in addition to stopping ARBs and/or adding low-dose CPS. Fludrocortisone was administered for a median of 169 days (interquartile range, 47-445). At the first follow-up after fludrocortisone administration, serum potassium dropped from 6.14±0.32 mEq/L to 4.52±1.06 mEq/L (p<0.001) in Group 1 and from 6.37±0.35 mEq/L to 4.08±0.74 mEq/L (p<0.01) in Group 2. Ten patients in Group 1 and five patients in Group 2 measured serum potassium levels at four outpatient visits before and after fludrocortisone administration, respectively. The frequency of serum potassium ≥6.0 mEq/L decreased from 19/40 (48%) to 2/40 (5%) (p<0.001) in Group 1 and from 11/20 (55%) to 0/20 (0%) (p<0.001) in Group 2. Eleven patients experienced sodium retention-related problems after fludrocortisone administration: 7 with worsening leg edema, 2 with pleural effusions, and 2 with pulmonary edema. In pre-dialysis CKD patients, fludrocortisone at low doses effectively reduced serum potassium levels; however, sodium retention was a common adverse effect.

Iron Deficiency Anemia in Patients with Chronic Renal Insufficiency at Tertiary Care Hospital in Northern Punjab

Anemia is a frequently encountered complication of chronic kidney disease (CKD) leading to worse outcomes in terms of quality of life and premature death. However, the current prevalence of iron deficiency anemia (IDA) in CKD is understudied in Pakistan. Objective: To assess the frequency of IDA in patients with CKD at Bewal International Hospital, Gujar Khan, Pakistan. Methods: A cross-sectional was executed at the Department of Nephrology, Bewal International Hospital, Pakistan from January 1, 2022, to June 30, 2022. The study comprised 97 patients aged &gt;13 years of either gender having CKD (GFR &lt;60 ml/min/1.73m²) for at least 90 days. All patients were tested for serum creatinine, ferritin, and hemoglobin levels. IDA was considered if hemoglobin was ≤12 mg/dL in women and ≤13 mg/dL in men. Results: Among 97 patients, there were 57(58.7%) males and 40(41.3%) females. The mean age was 51.23 ± 12.99 years while the mean disease duration was 6.01 ± 1.610 years. 57(58.7%) patients had IDA. IDA was more frequent in women with CKD (67.5%), compared to men (52.64%). However, this association was statically insignificant (p&gt;0.05). When data was stratified, a substantial association was found between IDA and the stage of CKD (p=0.007). There was no significant association between IDA and disease duration (p&gt;0.05). Conclusions: It was concluded that anemia is common in CKD patients, with a high prevalence in females. Stage 3–5 CKD is significantly associated with developing iron deficiency anemia. Early identification and timely management can avoid unfavorable outcomes in these patients.

Biological profile of secondary hyperparathyroidism in chronic renal failure patients

Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease, especially in hemodialysis patients. It is characterized by overproduction of parathyroid hormone in response to chronic deterioration of renal function. The aim of this retrospective study was to determine the average time to develop secondary hyperparathyroidism, analyze the initial phosphocalcic profiles, and evaluate the evolution of these profiles in hemodialysis patients, following the recommendations of the KDOQI 2003 and KDIGO 2009 groups. The study included 134 hemodialysis patients from two private dialysis centers. Data were collected from patients' medical records and analyzed using SPSS software. The results showed that the average time to develop secondary hyperparathyroidism was 3.15 years according to KDOQI recommendations and 4.64 years according to KDIGO recommendations based on parathyroid hormone levels. The initial assessment revealed an imbalance in phosphocalcic metabolism in approximately 20.1% to 22.5% of patients, a proportion that increased to 27.5% during follow-up, according to both sets of recommendations. In conclusion, secondary hyperparathyroidism is an inevitable complication of chronic kidney disease, affecting the vital and functional prognosis of hemodialysis patients. Diagnosis primarily relies on parathyroid hormone levels, associated with phosphocalcemia, vitamin D, and PAL analyses. Treatment aims mainly to maintain blood levels of calcium, phosphorus, and vitamin D within recommended limits and to reduce parathyroid response to phosphocalcic disturbances.

Low Protein Diet Reduces Proteinuria and Decline in Glomerular Filtration Rate in Advanced, Heavy Proteinuric Diabetic Kidney Disease.

Low protein diet (LPD) seems beneficial in ameliorating the complications of chronic kidney disease (CKD), in reducing proteinuria and the decline in kidney function, thus postponing the need for kidney replacement therapy (KRT). However, this type of intervention was less investigated in diabetic kidney disease (DKD). This is a single-center, prospective, interventional study that aims to assess the efficacy of reducing proteinuria and the rate of decline in the estimated glomerular filtration rate (eGFR). Patients with advanced DKD (stable proteinuria > 3 g/g and eGFR < 30 mL/min) with a good nutritional status and accepting a LPD were evaluated for inclusion. Ninety-two of the 452 screened patients (66% males, median age 61 years, proteinuria 4.8 g/g creatininuria, eGFR 11.7 mL/min/1.73 m2) completed the study. Intervention consisted of LPD supplemented with ketoanalogues of essential amino acids (KA) along with conventional nephroprotective therapy. Efficacy parameters were the variation in proteinuria and in eGFR from baseline to the end of the study. Proteinuria decreased 3-fold, and the rate of decline in eGFR decreased 5-fold in the intervention phase. No patient initiated KRT or died. LPD supplemented with KA seems effective in safely postponing KRT by reducing proteinuria and the decline in kidney function in advanced DKD.

#1395 Management of CKD patients and HK, as its main complication: degree of adoption of the multi-society consensus on CKD and HK in Spain

Abstract Background and Aims The high incidence, morbidity and mortality of Chronic Kidney Disease (CKD) makes it a public health problem, due to the difficulties in its early detection and management. Hyperkalemia (HK) is a common complication of CKD, also associated with high morbidity and mortality, impacting on the management of patients with CKD and leading sometimes to deoptimization of their treatment. It has been shown that the development of multidisciplinary consensus contributes to improving patient management. With this objective, the multi-society consensus documents –Information and consensus document for the detection and management of chronic kidney disease (2022)- and –Recommendations for the management of hyperkalemia in the emergency department (2022)- have been published. The aim of this study is to analyze the degree of adoption of the recommendations of both consensus in clinical practice in Spain, in order to identify potential areas of improvement in the management of CKD patients with HK. Method This study is based on the perceptions obtained through the discussion on the applicability of the national consensus documents for the management of CKD and HK. To this end, two medical education programs focused on CKD and HK, respectively, were carried out to discuss the applicability of both consensuses. In total, 41 meetings were held (14 from ERC and 27 from HK) from April 2022 to April 2023, involving a total of 542 healthcare professionals (HCPs) (nephrologists and emergency physicians). The main hypothesis was that neither the consensuses are being followed regularly in Spanish clinical practice. All responses were coded numerically, and a national mean was created based on the meeting means. Results The majority of nephrologists who participated in the discussion of the consensus analysis consider that CKD is underdiagnosed (77%), and that the detection of albuminuria is not routinely performed in Primary Care (PC) (72%). Furthermore, half of the nephrologists point out that referrals from PC do not meet the recommended criteria. In relation to treatment, almost 90% of nephrologists would follow the recommendations for the use of RAASi (renin angiotensin aldosterone system inhibitors) and Dapagliflozin very frequently. Regarding HK (a complication of CKD), 42% of HCPs considered that 30-40% of patients with CKD and/or HF suffered a second episode of HK. In relation to its management, only 21% of HCPs considered that the recommendations to maintain treatment with RAASis were followed. Of those who modified it, more than 50% did not consider reintroducing it or considered it little. 33% of HCPs did not show willingness to use the new antihyperkalemia treatments upon discharge. 50% of the participants said they did not have access to them. Regarding follow-up, 54% considered that it should be done by PC specialists. Conclusion The recommendations specified in the CKD and HK management consensuses are being applied less than desired in Spanish clinical practice. Especially highlighting the lack of detection of albuminuria and non-compliance with the referral criteria in patients with CKD, which is consistent with the high underdiagnosis described in Spain. Furthermore, the recommendation of not to modifying the RAASi treatment for the management of HK is not regularly adopted, despite of its impact on the morbidity and mortality of these patients. This information could help to guide future interventions that aim to improve the diagnosis and management of patients with CKD and/or HK.

#1825 Treating hyperphosphatemia in CKD via targeting Npt2a in the kidney

Abstract Background and Aims Targeting the renal sodium phosphate cotransporter 2a (Npt2a) offers a novel strategy for treating hyperphosphatemia in chronic kidney disease (CKD). In patients with and without reduced kidney function, hyperphosphatemia is associated with cardiovascular complications and currently treatment options are limited. Method To study the role of a novel Npt2a inhibitor (PF-06869206) we used in vitro (Opossum kidney [OK] cells) and in vivo approaches (C57Bl/6 and Npt2a knockout [Npt2a−/−] mice). As models of CKD, 5/6 nephrectomy (5/6 Nx) as well as novel Alport/Npt2a knockout mice (Alport/Npt2a−/−) were studied. Results OK cell experiments showed that the Npt2a inhibitor caused dose-dependent reductions of Na+-dependent Pi uptake (IC50: ∼1.4 μmol/L) and Michaelis-Menten kinetics identified a ∼2.4-fold higher Km for Pi in response to Npt2a inhibition with no significant change in apparent Vmax, indicating a competitive mode of action. In vivo, Npt2a inhibition enhanced urinary excretions of Pi, Ca2+, and Na+ dose-dependently, which is recapitulated in animal models with reduced kidney function (5/6 Nx and Alport mice). Reductions in plasma Pi occur within 30 minutes and reach a maximum (40-50%) after 2 hours, this coincided with ∼50% reductions in PTH levels. No effects on FGF23 were observed in this time frame. In C57Bl/6 mice qualitative immunohistochemistry after 24 hours showed reductions in Npt2a labelling in apical microvilli compared to vehicle treatment. Providing proof of concept, Npt2a−/− and Alport/Npt2a−/− mice confirmed specificity of the drug, effects on urinary and plasma Pi were absent. Further electrophysiological studies in acutely isolated connecting tubule/cortical collecting duct showed that open probability of the epithelial Na+ channel (ENaC) was reduced in response to Npt2a inhibition, suggesting that the natriuretic effect is mediated, at least in part, by inhibition of ENaC. Conclusion Npt2a inhibition offers a promising therapeutic approach for treating hyperphosphatemia and possibly offers the opportunity of reducing cardiovascular complications in CKD.

#3011 Pathophysiological link between renal and cardiovascular disease in patients with type 2 diabetes mellitus: preliminary results from a proteomic study

Abstract Background and Aims Diabetic kidney disease (DKD) affects nearly 40% of people with diabetes and is the leading cause of chronic kidney disease (CKD). A high prevalence of cardiovascular disease (CVD) is known in this population. Indeed, DKD and CVD are often related and lead to worse outcomes in type 2 diabetes mellitus (T2D), i.e. cardiac fibrosis and CV events are frequently described in patients with DKD. However, specific associations and accurate prediction biomarkers for DKD and CVD progression in T2D are still lacking as various proteins may play a multi-mechanistic role. Lipocalin-2 (LCN2) is involved in several pathophysiological processes (inflammation, renal disease and cardiometabolic complications in CKD). Its leukocyte-chemoattractant effect has shown to reduce CVD in experimental models of cardiomyopathy when suppressed. Excess LCN2 in CKD is a determinant of disease progression, but also a potent mediator of cardiac injury in CKD. Insulin-like growth factor binding proteins (IGFBPs) also play an important role in cell homeostasis by regulating cell transcription, migration, and apoptosis. IGFBP-3 down-regulation has demonstrated to be a predictor of rapid renal progression in T2DM. On the other hand, IGFBP-6 increases when GFR drops, being involved in the pathophysiological process of CKD as an apoptosis-inducing protein In this context, a proteomic-based approach would optimise the clinical utility of multiple plasma biomarkers. The aim was to identify proteins associated with DKD, cardiac fibrosis (estimated by the PICP biomarker) and the presence of a new CV event. Method A prospective cohort of 91 T2D patients, with a minimum follow-up of 3 years (mean: 4 years) was analysed. We evaluated the association between rates of change in GFR and PICP during follow-up (fold-change: end/initial) and their interaction with the development of a composite of cardiovascular (CV) events: CV death, stroke, ischaemic heart disease, atrial fibrillation, valvular heart disease and CV-related hospitalisation. In addition, ninety-two proteins were quantified in serum samples using a multiplex proximity extension assay with high-throughput protein detection technology (Olink proteomics, Cardiometabolic panel). Associations between variations in these proteins and changes in PICP and eGFR (all expressed as fold change from baseline) were assessed using linear regression analyses adjusted for their respective baseline values. All analyses were adjusted by multiple testing (Benjamini-Hochberg, FDR = 0.05%) using R software. Results Sixty-eight (74.7%) men and 23 (25.3%) women were included in the analysis. The mean age at baseline was 65.8 years, and the mean follow-up was 4 years (minimum 3 years). Sixteen cardiovascular events were recorded. An inverse association was observed between GFR and PICP (p = 0.003). Interaction analysis showed that this correlation occurred only in patients with incident CV events (p for interaction &amp;lt;0.001) (Fig. 1). By proteomic analysis (Fig. 2) several proteins were found to be significantly related to one of the three parameters studied (change in GFR, change in PICP and change with cardiovascular event), of which 3 proteins presented an overlap for all the parameters analysed: Lipocalin 2 (LCN2) and Insulin-like growth factor binding proteins 3 and 6 (IGFBP3 and IGFBP6). Interestingly, LCN2 and IGFBP6 were more highly expressed in patients with CV events whereas IGFBP3 was downregulated in these patients. Conclusion In patients with DKD, worsening enal function is associated with elevated circulating levels of the collagen synthesis biomarker PICP, particularly in those who developed at least one CV event. The link shown with LCN2, IGFBP-6 and IGFBP-3 shed light on possible multi-mechanistic pathways involved in DKD and narrow the scope towards a common pathway involving an interaction between pro-apoptotic and local inflammatory factors.

#2009 FGF23 in patients with diabetic kidney disease and atherosclerosis

Abstract Background and Aims Diabetes mellitus (DM) and chronic kidney disease (CKD) are risk factors for vascular atherosclerosis, a pathological process with an important inflammatory component. The coexistence of these conditions in patients with diabetic kidney disease (DKD) has additive effects with worst cardiovascular mortality and morbidity rates when compared to non-diabetic CKD patient on cardiovascular outcomes. Accumulating research has shown that increased levels of bone-derived fibroblast growth factor 23 (FGF23), the major phosphate-regulating hormone, constitute a novel predictor of cardiovascular and all-cause mortality in CKD patients, with potential effects on disorders of glucose metabolism as well. The objective of this comparative study is to determine the differences in FGF23 levels in two groups of patients with CKD, with and without DM, matched by age, sex and renal function, all of them with clinical atherosclerotic disease. We also evaluated the relationships of FGF23 with several inflammatory markers and parameters of glucose metabolism. Method Sixty-six patients with CKD stages 3-4 (33 of them with DM) and diagnosed with peripheral vascular disease were included in the study. Whole blood and serum samples were obtained from all participants. CRP values, neutrophil/lymphocyte (N/L) ratio, HbA1c (%), fasting glucose, and Triglycerides and glucose (TyG) index, among other parameters, were obtained using standardized routine methods. Circulating levels of the intact form of FGF23, tumor necrosis factor (TNF) α, interleukin (IL) 6, and IL10 were determined by ELISA immunoassays in both groups. We also performed gene expression analysis for these three cytokines in peripheral blood cells (PBCs) using qPCR. Results The mean values of eGFR, ACR and phosphate were 37.6 ± 11.2 ml/min/1.73 m2; 294.1 ± 271.2 mg/g; 3.8 ± 0.82 mg/dL; respectively without differences between patients with and without DM The median circulating FGF23 values were higher in the DM group (51.59 [37.73-89.68] vs. 38.1 [33-54.14] pg/mL; p&amp;lt;0.001). Likewise, patients with DM presented higher levels of TNFα both in serum concentration (1.78 [0.72-2.47] vs. 1.28 [1.01-1.88] pg/mL; p&amp;lt;0.01) as in the expression of mRNA in PBCs (2.1 ± 1.26 vs. 1.87 ± 1.16 a.u.; p&amp;lt;0.05). No differences were observed for IL6 and IL10 levels, nor for CRP concentration or N/L ratio. As expected, fasting glucose, HbA1c and TyG index were higher in the group of subjects with DM. FGF23 was inversely correlated with eGFR (r=−0.435, p&amp;lt;0.0001), while it showed a positive association with ACR (r=0.416, p&amp;lt;0.001) and, interestingly, with proinflammatory cytokines including circulating TNFα (r=0.44, p&amp;lt;0.001), circulating IL6 (r=0.27, p=0.04), and TNF mRNA expression in PBCs (r=0.245, p=0.047). Furthermore, circulating FGF23 was also direct and significantly correlated with HbA1c (r=0.34, p&amp;lt;0.01). Conclusion These results suggest that FGF23 levels are higher in DKD than in non-DM CKD patients with similar renal function. DKD patients also had higher levels of the proinflammatory cytokine TNFα. Our results also show positive correlations of FGF23 with the inflammatory cytokines TNFα and IL6, as well as with HbA1c. Previous studies, shown that elevated TNFα and glucose promote FGF23 production, which may help to explain the higher levels of FGF23 in patients with DM Future studies should clarify whether FGF23 is simply a marker of atherosclerosis disease severity or a contributing factor to this complication in CKD.

#571 Vitamin D receptor from VSMCs regulates vascular calcification during CKD: a potential role for miR-145a

Abstract Background and Aims Vascular calcification (VC) is a highly prevalent complication of chronic kidney disease (CKD) and is associated with the higher morbidity-mortality of patients with CKD. Vitamin D receptor (VDR) has been proposed to play a role in the osteoblastic differentiation of vascular smooth muscle cells (VSMCs), but the involvement of vitamin D (1, 25D) in VC associated to CKD is controversial. Accumulating evidence points to microRNAs as important players in the process of VC and recent studies show that miR-145a expression decreases in VSMCs during VC. In addition, VDR has been considered as a potent regulator of these small molecules, while miR-145a was identified as a target for 1, 25D. Our aim was to determine the role of local vitamin D signalling in VSMCs during CKD-induced VC and the involvement of miR-145a in this process. Method We used epigastric arteries from CKD-affected patients and from individuals with normal renal function. In vivo, we employed an experimental model of CKD-induced VC in mice with conditional deletion of VDR in VSMC (Myh11-CreERT2+ VDRlox/lox), while in vitro, we used mouse VSMC with (VDRwt) or without VDR (VDRko) incubated in calcification media. Transfection experiments with mmu-miR-145a-5p mimic or mmu-miR-145a-5p inhibitor were carried out in mouse VDRwt VSMCs. Results CKD-affected patients showed an increase in VC, alongside an increased arterial expression of VDR compared with controls with normal renal function. Conditional gene silencing of VDR in arterial VSMCs led to a significant decrease of VC in the mouse model of CKD, despite similar levels of renal impairment and serum calcium and phosphate levels. This was accompanied by lower arterial expression of osteopontin (OPN) and lamin A, and a higher expression of sclerostin (SOST). Runx2 was increased in arteries of both CKD groups independently of the presence of VDR in VSMCs. Furthermore, CKD-affected mice showed a reduction of miR-145a expression in calcified arteries, which was significantly recovered in animals with deletion of VDR in VSMCs. In vitro, the absence of VDR prevented VC, inhibited the increase of OPN, and re-established the expression of miR-145a. Forced expression of miR-145a in vitro in VDRwt VSMCs blunted VC and decreased OPN levels. Mir-145a levels markedly decreased both in human and mouse VDRwt VSMCs incubated in calcification media and 1, 25D. Overexpression of miR-145a suppressed the levels of OPN induced by 1, 25D, while the inhibition of mir-145a led to a significant increase in OPN levels, even higher than in cells treated solely with 1, 25D. A predicted miR-145a-binding site was detected at the 3’UTR of OPN mRNA transcript, through the extended seed region of the miRNA, pointing to OPN as a possible target of mir-145a during VC in CKD. There were no significant differences in Runx2 levels in 1, 25D-treated cells after transfection with mir-145a mimic or inhibitor. Conclusion VDR is induced in calcified VSMCs during CKD where it can modulate the expression of promoters and inhibitors of VSMC transdifferentiation, as well as small noncoding RNA molecules such as mir-145a that modulate VC. The regulation of these pathways by VDR seems to be essential for the settings of CKD-induced VC, as deletion of VDR from VSMCs prevented it.

#2070 Associations of fecal and plasma levels of SCFAs with gut microbiota and clinical characteristics in non-dialysis renal anemia patients

Abstract Background and Aims Renal anemia is one of the most common complications of Chronic Kidney Disease (CKD). The gut-kidney axis hypothesis has led to numerous studies showing that patients with CKD have a distinct gut microbiota structure compared with controls and that changes in gut microbiota correlate with disease severity and progression. The short-chain fatty acids (SCFAs) are speculated to be pivotal in the gut-kidney crosstalk. However, the role of SCFAs in renal anemia has not been elucidated. This study aimed to explore and compare the fecal and plasma levels of SCFAs in non-dialysis renal anemia patients and healthy controls to reveal the potential interactions among SCFAs, gut microbiota, and clinical features of renal anemia, which may provide new light on further studies. Method A cohort of 30 non-dialysis renal anemia patients and 20 healthy controls were recruited from the First Affiliated Hospital of Zhengzhou University. Gut microbiota was analyzed using 16S rRNA gene amplification sequencing. Fecal and plasma concentrations of SCFAs were measured using GC-MS/MS platform. The clinical characteristics of patients with renal anemia and controls were evaluated. Results Renal anemia patients displayed altered microbiota composition compared to healthy subjects. The relative abundance of Enterobacterales, Enterobacteriaceae, Escherichia-Shigella, and Escherichia-coli were higher in patients with renal anemia, and the Lachnospiraceae family decreased in renal anemia patients. In contrast, the relative abundance of Lachnospirales, Lachnospiraceae, and Bacteroides vulgatus was higher in the control group. Patients with renal anemia had higher fecal and plasma concentrations of SCFAs compared to controls. The fecal and plasma concentrations of SCFAs were significantly different not only between the patients with renal anemia and controls but also in the different severity of renal anemia. Moreover, different types of SCFAs are intimately associated with clinical characteristics. The applications of medications may exert effects on the fecal and plasma SCFAs. A positive correlation was obtained between Lachnospirales and the plasma SCFAs. The levels of acetic acid and caproic acid in fecal and the levels of acetic acid, propionic acid, and butyric acid in plasma were all positively correlated with the abundance of Cyanobacteria. Conclusion The gut metabolites SCFAs are tightly linked to the alterations of gut microbiota and clinical characteristics of renal anemia. Further studies are warranted to elucidate the relationships more in-depth.

#289 Lipocalin-2 promotes cardiovascular calcification in chronic kidney disease by upregulating STAT3/NCOA4-mediated ferritinophagy and ferroptosis

Abstract Background and Aims Cardiovascular calcification (CVC) is a common complication of chronic kidney disease (CKD) and contributes to cardiovascular morbidity and mortality without any effective therapies. To date, the underlying mechanism of CKD-CVC has not been elucidated. Recent studies suggest that ferroptosis is a novel programmed cell death that may play a role in the process of CKD-CVC, but the mechanism is largely unclear. Ferritinophagy is an important inducer of ferroptosis that is regulated by nuclear receptor coactivator 4 (NCOA4). However, the relationship between ferritinophagy and CKD-CVC has not been explored. Lipocalin-2 (LCN2) is an iron-trafficking protein that has been associated with both osteogenesis and ferroptosis, but the exact role and molecular mechanism of LCN2 in CKD-CVC needs to be explored. Method A cross-sectional clinical study was utilized to examine the association between LCN2 expression and CKD-CVC in serum and calcified radial arteries of CKD patients. LCN2 knockout mice, their wild type littermates and mice infected with VSMCs-targeted adeno-associated virus encoding LCN2 gene or negative control gene were all fed by the high adenine and phosphate diet to induce CKD-CVC.VSMCs transfected with LCN2-overexpressing lentivirus, LCN2-shRNA lentivirus or LCN2 siRNA and recombinant LCN2 stimulated VSMCs were treated under the condition of calcifying medium to investigate the role of LCN2 in CKD-CVC in vitro. Cardiovascular calcification was evaluated by Von-kossa staining and tissue calcium content assay. VSMCs calcification were checked by the Alizarin Red Staining and cellular calcium content assay. Cellular reactive oxygen species (ROS) were measured by the DCFDA assay. Lipid peroxidation was measured by the fluorescence of the fatty acid analog C11-BODIPY581/591 probe. Intracellular labile ferrous iron levels were measured by fluorescence of Phen Green SK probe and ferro-orange probe. Transmission electron microscopy was also used to examine mitochondrial change of ferroptosis. Results The cross-sectional study identified that LCN2 levels in serum and radial arteries were significantly increased as the severity of CKD-CVC increased. High adenine and phosphate diet intake provokes renal fibrosis and cardiovascular calcification in vivo. In vitro, five-days high phosphate sodium stimulation induced calcium deposition and osteoblastic trans differentiation of VSMCs. Meanwhile, high phosphate also increased the levels of ferroptosis in VSMCs as evidenced by decreased cell viability, iron and ROS accumulation, upregulated PTGS2 and MDA levels, reduced glutathione peroxidase 4 (GPX4) levels and significantly mitochondrial damage in VSMCs. Intriguingly, calcium deposition in VSMCs could be reversed by the ferroptosis inhibitor ferrostatin-1. LCN2 expression was significantly upregulated both in the aorta of mice and calcified VSMCs. Compared with WT mice, deletion of LCN2 inhibited cardiovascular calcification whereas VSMC-targeted LCN2 overexpression aggravated CKD-CVC. Consistently, LCN2 knockdown also alleviated calcium deposition of VSMCs. Meanwhile, inhibition of ferroptosis were observed after LCN2 silencing as evidenced by decreased ferrous and lipid oxidation while increased levels of GPX4. Mechanically, we demonstrated high phosphate increased the protein level of NCOA4 and downregulated FTH1, which was reversed by depletion of LCN2. Knockdown of NCOA4 partly alleviated the ferritin reduction, ferroptosis, and calcification in VSMCs, indicating that NCOA4-mediated ferritinophagy was required for VSMCs calcification. Furthermore, we found that the recombinant LCN2 treatment significantly upregulated phosphorylated STAT3. STAT3 signaling inhibitor abolished the recombinant LCN2 induced NCOA4 upregulation and calcification in VSMCs. Conclusion Our findings indicate that the pro-calcific effect of high phosphate is due to VSMCs ferroptosis mediated by LCN2 upregulation. LCN2 silencing alleviates CKD-CVC by suppressing the STAT3/ NCOA4/FTH1 signaling mediated ferritinophagy. LCN2 could serve as a candidate therapeutic strategy for CKD-CVC.

#2938 The association between serum iron biomarkers and health-related quality of life in patients undergoing dialysis

Abstract Background and Aims Anemia is a very common complication of chronic kidney disease, affecting most patients undergoing dialysis. Iron deficiency, one of the causes of anemia, is generally a second consideration in the management of anemia. Nephrologists mainly focus on the correction of hemoglobin, often prescribing iron therapy for this indication only. However, iron has important physiological functions besides erythropoiesis. Conversely, iron overload can lead to oxidative stress and cellular damage. Therefore, nephrologists have been cautious to prescribe iron therapy to patients with already high serum iron levels. This caution has been underscored by studies linking higher levels of iron to increased mortality. Unfortunately, evidence is lacking regarding the impact of iron on important patient-reported outcomes like health-related quality of life (HRQoL). Therefore, the aim of this study is to explore the association between serum iron biomarkers, health-related quality of life (HRQoL) and the presence of anemia-related symptoms over a one-year period in patients undergoing dialysis. Method Data were obtained from the multicenter, prospective, observational Dutch nOcturnal and hoME dialysis Study To Improve Clinical Outcomes (DOMESTICO). Adult patients new to dialysis were included, and had a baseline and follow-up assessments at 3, 6 and 12 months, with measurements of serum iron biomarkers ferritin and transferrin saturation (TSAT). HRQoL, encompassing physical and mental HRQoL, was measured using the validated 12-item Short Form Health Survey (SF12, summary scores ranging from 0 to 100). The presence of anemia-related symptoms: fatigue, shortness of breath, restless legs and muscle cramps were assessed using the Dialysis Symptom Index. Patients were categorized into 4 groups depending on their ferritin levels (μg/L): &amp;lt;200, 200–500 (reference), &amp;gt;500–700 and &amp;gt;700, and into 3 groups depending on their TSAT levels (%) at baseline: &amp;lt;20, 20–39 (reference), and ≥40. Longitudinal analyses were conducted using sequential conditional mean models to adjust for time-independent and time-varying confounding. All analyses captured the overall association over a one-year follow-up. Results We included 1069 patients, of whom 76% started hemodialysis, the median age was 68, 66% were male, and 32% were receiving iron therapy. Over a one-year follow-up, patients with ferritin &amp;lt;200 μg/L had similar physical HRQoL (MD=0.5 ; 95% CI –2.4 to 3.3 ) and mental HRQoL (MD=0.04 ; 95% CI -2.0 - 2.0) compared to the reference group with ferritin between 200–500 μg/L. Patients with ferritin between 501–700 μg/L also had a similar physical and mental HRQoL mental HRQoL compared to those with ferritin between 200-500 μg/L. This was also found for patients with ferritin above 700 μg/L (Fig. 1). Similarly, patients with TSAT levels below 20% and patients with TSAT levels ≥40% had comparable physical and mental HRQoL compared the reference group of patients with a TSAT between 20-39% (Fig. 2). For the secondary objectives, we found no significant differences in the anemia-related symptoms fatigue, shortness of breath, restless legs, or muscle cramps between patients with various levels of ferritin nor between the various TSAT groups. Conclusion We found that dialysis patients with higher or lower levels of ferritin or TSAT did not have a significantly different physical or mental HRQoL over a one year-follow up after starting dialysis. Similarly, no significant differences were found in the presence of fatigue, shortness of breath, restless legs, and muscle cramps between patients with these higher or lower levels of serum iron markers. And although iron levels do have impact on clinical outcomes such as mortality, these results suggest that they do not influence patient reported outcomes such as physical and mental HRQoL.

#1168 Responsiveness to roxadustat in chronic kidney disease associated anemia patients by baseline hemoglobin: a secondary analysis of ROXSTAR Registry

Abstract Background and Aims Anemia is a common complication of chronic kidney disease (CKD), and associated with increased morbidity and mortality, as well as a reduced quality of life (QoL). Various studies have shown anemia treatment in CKD patients improved the QoL. However, in ROXSTAR Registry (ChiCTR2100046322), although roxadustat corrected anemia and maintained hemoglobin (Hb) effectively, no improvement in QoL was observed. Hence, we conduct this secondary analysis of ROXSTAR to evaluate the Hb response to roxadustat treatment and the change of QoL in dialysis-dependent (DD) and non-dialysis-dependent (NDD) patients stratified by baseline Hb. Method This was a secondary analysis using existing data collected in the ROXSTAR Registry. DD &amp; NDD Patients who received at least one dose of roxadustat and had at least one post baseline Hb were included. We described the Hb response to roxadustat in patients with lower baseline (Hb &amp;lt;80) g/L &amp; higher baseline Hb (≥80 g/L). The changes from baseline to week 12 &amp; week 24 in Quality of Life (QoL) assessed by SF-36 Vitality (V) &amp; Physical Function (PF) subscales, and Rapid Assessment of Physical Activity (RAPA) Strength &amp; Flexibility scores were also analyzed respectively. Results Overall, 1998 patients (1508 DD patients and 490 NDD patients) were included, there were 238 patients (131 male [55.0%]) with a mean (standard deviation [SD]) age of 49.1 (13.6) years in the lower baseline Hb group, and 1760 patients (947 male [53.8%]) with a mean age of 50.3 (13.5) in the higher baseline Hb group. The overall mean baseline Hb was 97.3 (13.9) g/L, with 71.4 (7.2) g/L and 100.8 (10.5) g/L in the two groups respectively. The median (min, max) ferritin and mean transferrin saturation were 149.6 (3.3, 2304.0) ng/mL &amp; 22.8% (15.5) % in the lower baseline Hb group and 169.8 (3.8, 3966.0) ng/mL &amp; 30.6% (15.7%) in the higher baseline Hb group. More patients with CRP above normal limit were in the lower baseline Hb group (30.7%) compared to patients in the other group (19.7%) (Table 1). Mean weekly roxadustat dose started at 320 mg and was maintained during the first 12 weeks (correction phase) then slightly decreased to 300 mg from week 12 until week 52 (maintenance phase) in patients with baseline Hb &amp;lt;80 g/L, while it was from 286 mg to 260 mg during the correction phase then decreased and maintained at around 230 mg from week 12 to week 52 in patients with baseline Hb ≥80 g/L. The mean Hb change from baseline averaged over weeks 24-36 and 36-52 was 31.9 [95% CI: 29.9, 33.9] g/L &amp; 33.7 [95% CI: 31.8, 35.6] g/L in the lower baseline Hb group, and 11.3 [95% CI: 10.6, 12.0] g/L &amp; 11.1 [95% CI: 10.5, 11.8] g/L in the higher baseline Hb group. The proportion (%) of patients with mean Hb ≥100 g/L averaged over the same period were 58.8% [95% CI: 51.8%, 65.7%] &amp; 68.6% [95% CI: 61.8%, 75.3%] in the lower baseline Hb group, and 86.5% [95% CI: 84.7%, 88.3%] &amp; 88.2% [95% CI: 86.5%, 90.0%] in the higher baseline Hb group. Patients with baseline Hb &amp;lt;80 g/L had numerically higher mean increases from baseline to week 12 and 24 in SF-36 V and PF sub-scores (Table 2), though no clinical meaningful change was observed in either group. Conclusion Roxadustat effectively corrected anemia in DD and NDD patients regardless of baseline Hb level. There was no clinical meaningful improvement in QoL for either group. The weekly dose of roxadustat to correct and maintain Hb was higher in patient with baseline Hb &amp;lt;80 g/L than in patients with baseline Hb ≥80 g/L.

N-Terminal Pro-Brain Natriuretic Peptide Correlates with Ghrelin and Acyl-Ghrelin in Pre-Dialysis Chronic Kidney Disease.

Pro-B amino-terminal natriuretic peptide (NT-proBNP) is a diagnostic marker for heart failure (HF), a severe complication of chronic kidney disease (CKD). However, its significance in CKD is not clear, as other factors, such as renal function, may also have an impact. Recent studies have shown that ghrelin treatment is effective in HF in the general population, but the impact of ghrelin on cardiac function in CKD patients is still unknown. Our study aimed to investigate the factors associated with NT-proBNP in pre-dialysis CKD patients and to evaluate the correlation between NT-proBNP and ghrelin and acyl-ghrelin, molecules determined using ELISA methods. In a cross-sectional observational study, we included 80 patients with pre-dialysis CKD, with a mean age of 68 years and 50% men. The median values for NT-proBNP were 351.8 pg/mL, for acyl ghrelin 16.39 pg/mL, and for ghrelin 543.32 pg/mL. NT-proBNP was correlated with ghrelin (p = 0.034, r = 0.24), acyl-ghrelin (p = 0.033, r = -0.24), estimated glomerular filtration rate (p = 0.027, r = -0.25), serum urea (p = 0.006, r = 0.31), and ferritin (p = 0.041, r = 0.28). In multivariate analysis, ghrelin (p = 0.040) and blood urea (p = 0.040) remained significant predictors for NT-proBNP levels. NT-proBNP was a significant predictor for acyl-ghrelin (p = 0.036). In conclusion, in pre-dialysis CKD patients, a high value of NT-proBNP was associated with a high value of total ghrelin and a low value of acyl-ghrelin.

#2191 Platelet function in chronic kidney disease; can flow cytometry guide in the difficult balance between risk for bleeding versus thrombotic events?

Abstract Background and Aims Increased risk of bleeding is a well-known complication of chronic kidney disease (CKD). However, these patients also have an increased risk of thrombotic events. Several studies have implicated both impaired and enhanced platelet function in patients with chronic kidney disease, but results vary between different studies and methods. Flow cytometry has emerged as a new method to study platelet function. Our aim was to investigate platelet function using flow cytometry in patients with chronic kidney disease. Method 20 patients were included between February and May 2023. Pre-dialytic patients with an eGFR between 8-20 mL/min/1,73 m2 were included, mean eGFR 14.7 mL/min/1,73 m2. Patients with platelet levels &amp;gt;100 × 109/L were included. Medication in the form of anticoagulants, NSAIDs, platelet inhibitors or SSRIs were used as exclusion criteria. Platelet activation assay was performed with flow cytometry. The expression of activation markers PAC-1 (activated GPIIb/IIIa), CD62P (P-selectin) and CD63 (dense granules) were analysed before and after activation with ADP, CRP-XL (collagen stimulating peptide, activates GPVI) or TRAP-6 (stimulates platelet activating receptor 1, PAR1). Platelets from 20 healthy control subjects were analysed for comparison. Results The level and size of platelets (MPV) were comparable in both groups. There were significantly higher levels of D-dimer in the CKD group vs healthy controls (1,17 mg/L FEU vs 0,27 mg/L FEU). Except for the decreased expression of activated GPIIb-IIIa receptor after activation with ADP and CRP-XL in one patient, the platelet activation did not significantly differ between CKD patients and healthy controls. Conclusion No significant differences in the activation of platelets were observed between the CKD population and the healthy controls when analysed by flow cytometry. Elevated levels of D-dimer in CKD patients have previously been described and are believed to be due to increased fibrin formation, lysis and decreased renal clearance. Further studies in a larger patient population, including thrombocytopenic patients are planned, with greater focus to be placed on dense granula quantities which may correlate with decreased levels in the CKD population.

#2382 Renal tubule-derived EVs carrying complement 3 aggravate CKD vascular calcification by downregulating autophagy in vascular smooth muscle cells

Abstract Background and Aims Vascular calcification (VC) is a serious complication of chronic kidney disease (CKD) patients, recognized in KDIGO guidelines as a leading risk factor for cardiovascular diseases. Despite acknowledgment, the mechanisms of VC in CKD remain unclear. The kidneys intricately regulate blood vessel pathophysiology. Clinical studies suggest a correlation between elevated blood complement levels in CKD and arterial calcification, hinting at complement involvement in CKD-associated VC. Renal-origin complement, a significant source of circulating complement, activates in CKD. Extracellular vesicles (EVs), mediating intercellular communication, transport complement-related proteins in various physiological and pathological processes. Studies suggest that plasma EV rather than EV-depleted plasma causes pathogenic calcium salt deposition in smooth muscle cells. This study explores how renal-origin EVs carrying complement mediate CKD-associated VC. Method From October 2021 to August 2023, data from 110 clinical patients were gathered, encompassing both blood C3 levels and CT images of the thoracic aorta. Subsequently, we conducted a scoring analysis of the CT images and carried out correlation analyses. A CKD-associated VC model was induced by feeding C57BL/6j mice an adenine and high-phosphate diet for 16 weeks. Techniques, including WB, PCR, and immunofluorescence, detected complement activation and localization in renal tissues. EVs were isolated from kidney tissue and plasma and identified by NTA, electron microscopy, WB, etc. WB examined C3 and tubular markers of EVs. At the same time, the Elisa method was used to detect C3 in plasma, plasma EV, and EV-depleted plasma. Immunofluorescence investigated tubular-derived EVs uptake in calcified arteries. Tubular-derived EVs, C3a, C3aR receptor inhibitors (SB290157), and autophagy inhibitors (3-MA) intervened in high-phosphate-induced vascular smooth muscle cells (VSMCs). PCR and WB assessed calcification indicators, complement receptors, and autophagy-related indicators. Alizarin Red staining observed calcification nodules. Transcriptome sequencing was performed on control, high-phosphate, and renal tubular-derived EV intervention groups of VSMCs. An in vivo model infused renal tubular-derived EVs and injected C3aR inhibitors and autophagy inhibitors, measuring complement activation and VC indicators. Results There is a correlation between C3 and thoracic aorta calcium score in CKD patients, with a correlation coefficient of 0.3750 (P &amp;lt; 0.01). The CKD-associated VC mice model revealed complement C3 activation in renal tubules, secreted into the blood through EVs. The C3 proportion of plasma EV in CKD patients was significantly higher than that in the control group, but there was no statistical difference between the EV-depleted plasma control group and the CKD group. Immunofluorescence indicated tubular-derived EV uptake by the calcified vascular wall. In vitro, tubular-derived EVs enhanced VSMC osteogenic differentiation and upregulated C3aR, mimicking C3a intervention effects. C3aR receptor inhibitors produced opposing effects. Transcriptome sequencing suggested renal tubular-derived EVs downregulated VSMC autophagy-related pathways; in vitro autophagy inhibition reversed osteogenic differentiation. In vivo, reinfusing renal tubular-derived EVs exacerbated complement activation and VC, while injecting C3aR inhibitors and autophagy inhibitors alleviated CKD-associated VC. Conclusion This study confirms that tubular-derived EVs carrying C3 downregulate autophagy in VSMCs, mediating CKD-associated VC. These findings provide insights into understanding CKD-associated VC initiation and progression, revealing potential therapeutic targets.

#294 Pragmatic literature reviews to populate a patient-level model to project the future clinical burden of CKD in low-and middle-income countries

Abstract Background and Aims Chronic Kidney Disease (CKD) affects approximately one in ten people around the world and is associated with an increased risk of adverse cardiorenal outcomes and mortality. In low- and middle-income countries (LMICs), the situation is aggravated by the paucity of kidney replacement therapies (KRTs). The objective of this study was to review the literature around CKD prevalence to understand the future epidemiology and economic burden of CKD in four LMICs from different continents. Method Inside CKD is a project designed to perform a microsimulation on a representative patient cohort to simulate renal disease progression into the future, and to model the effects of interventions based on population and disease characteristics. A pragmatic literature review was performed to obtain the inputs required to adapt the Inside CKD model to project the epidemiological and economic burden of CKD in four World Bank (2022) classified LMICs (Bolivia, Kenya, Sri Lanka and Uzbekistan). Using a data quality scoring system designed for the Inside CKD programme, a model input template was created to guide the country-specific literature search, to identify country demographics, epidemiological data including CKD staging data, renal registries, comorbidities (type 2 diabetes and hypertension), complications data (stroke, myocardial infarction, heart failure) and economic data including health costs and quality-of-life measures. Additional needs, challenges or country specific risk factors have also been identified. Results Literature reviews identified the best sources of demographic, epidemiological data as well as the main drivers of CKD in the four countries (e.g. hypertension, type 2 diabetes, heart failure). In addition, the reviews identified the best proxy data to use when country-specific data was not available. The UN World Prospects database was selected to derive the current and future population dynamics in the four countries. For Kenya, data from local sources, sub-Saharan African and Uganda were utilised to estimate the primary drivers of CKD: a 2018 meta-analysis reported a CKD prevalence of 18% in sub-Saharan Africa and was used to derive the eGFR and UACR data required to project CKD prevalence. CKD prevalence by stage was also identified for Bolivia. A large-scale study across 12 countries with consistent methodology estimated a CKD prevalence of around 5.5% in Bolivia. CKD data from Kazakhstan was selected as a proxy for Uzbekistan, which had a low prevalence of 1.3%. Country-specific challenges were also identified: in Kenya, results showed the importance of malnutrition, infection and climate as key drivers of CKD. In Sri Lanka and Uzbekistan, environmental factors (air and water pollution) and agricultural activity may contribute to high CKD prevalence in rural areas alongside more common risk factors such as hypertension. In Sri Lanka, CKD has been estimated at around 8.2% in the general population versus 15.0% in areas where groundwater is consumed. For Bolivia, additional parameters including occupation, altitude, seasonal weather variation and extreme temperatures may exacerbate CKD risk. Conclusion CKD is a major public health problem in LMICs but with diverse drivers. Local capacities and healthcare financing priorities vary between regions and depend upon competing demands of acute conditions, infections and non-communicable diseases. Forecasting future CKD burden is helpful for policy and planning purposes. There is a clear need to tailor policies beyond early screening and proactive management to tackle country-specific challenges such as occupation, infection, seasonal weather variation and genetics.

#2818 Clinical outcomes of a pre-dialysis cohort in a tertiary renal centre in the United Kingdom

Abstract Background and Aims Patients with advanced chronic kidney disease (CKD) require significant resources in order to manage the complications of CKD, and provide education and planning for renal replacement therapy (RRT). To better gauge the clinical trajectory of these patients, we aimed to provide a descriptive overview of patients who attended the multidisciplinary Advanced Kidney Care Service (AKCS) clinic over 8 years in a tertiary renal referral centre in the United Kingdom. Patients are typically referred to this clinic once their estimated glomerular filtration rate (eGFR) drops below 20 ml/min/1.73 m2. Method This was a retrospective study of consecutive patients who first attended the AKCS clinic in our centre between September 2011 and September 2018, and last follow-up was the end of September 2023. Patients with a prior renal transplant, those with acute kidney injury with subsequent recovery of renal function, and those lost to follow-up were excluded. Patient details and outcomes were extracted from the hospital Electronic Patient Record including demographics, decisions regarding active or conservative management, timing of RRT initiation, first modality of RRT, transplantation, and mortality. The primary outcomes of interest included time to RRT, first modality of RRT, and death. Results A total of 1 957 patients were included. Of these 1,136 (58%) were male and 821 (42%) female. Median age was 69 years at the time of first AKCS review. A large proportion (80%) identified as white British, 13% as Asian or Asian British, 2% as Black or Black British, and the remaining as other ethnicities. Median eGFR was 16 ml/min/1.73 m2 (IQR 4-25 ml/min/1.73 m2) at first AKCS clinic. A total of 1 087 patients (56%) initiated RRT during follow-up. The first modality was haemodialysis in 622 (57%), peritoneal dialysis in 298 (27%), and a renal transplant in 167 patients (15%). Median time to RRT commencement was 12.2 months (IQR 6.4-30). A further 240 patients received a transplant after dialysis. Of the 870 patients who did not initiate RRT, 350 (40%) were documented as opting for conservative management. 756 (38.6%) patients died either before RRT initiation (434) or on the conservative care pathway (322). A further 583 (29.8%) who commenced RRT died during follow up. Median time to death from first AKCS review was 38.5 months in the active management group (21.8 months in those who died without RRT and 51.0 months in those on RRT) compared to a median of 29.7 months in the conservative group. Conclusion This study presents a descriptive analysis of long-term outcomes in a high-risk group of patients. Two-thirds of patients died within 5 years of their first AKCS review, demonstrating the high mortality burden in this population. Of those who died prior to RRT, 57.4% had opted for RRT or were undecided, highlighting the substantial competing risk of death prior to reaching end stage kidney disease. We are planning further work with this dataset including risk prediction modelling. The ability to risk-stratify and profile patients, including consideration of co-morbidities and clinical frailty score, would be beneficial for patients and healthcare providers when making decisions regarding RRT and conservative care.

#1841 Trimethylamine N-oxide (TMAO) induces the formation of endothelial extracellular vesicles

Abstract Background and Aims Endothelial dysfunction caused by the accumulation of uremic toxins is an important contributor to the development of cardiovascular disease in patients with chronic kidney disease (CKD). The uremic toxin trimethylamine n-oxide (TMAO) is associated with oxidative stress, vascular calcification, and inflammation, triggering the release of several proinflammatory molecules and Extracellular Vesicles (EVs). Clinical studies have shown that patients with CKD have high levels of circulating EVs, however, their role is still poorly understood. In this dysfunctional scenario, EVs can be used as damage biomarkers for CKD, as they carry information from their cells of origin. Here, we aim to elucidate the formation of EVs in endothelial cells exposed to TMAO. Method Human endothelial cells (EA.hy926, ATCC CRL-2922) were exposed for 24 h with TMAO at uremic concentrations (7.49 mg/L). EVs were isolated by differential ultracentrifugation. Protein concentration was analyzed by Pierce™ BCA Protein Assay Kit, and particle size and particle concentration were analyzed by NanoParticle Tracking Analysis (NTA), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM). EVs were stained with calcein and their internalization in endothelial cells was analyzed with Fluorescence Confocal Microscopy. Results TMAO treatment at uremic concentration induced the formation of EVs with a size of 202.8 ± 3.1 nm (image 1B) and 1.09 × 109 ± 2.68 × 107 particles/mL and a total protein concentration of 88.57 µg/mL. The morphological features of EVs are shown in images 1C-1F. TMAO-induced EVs were incorporated by endothelial cells, being dispersed in the cytoplasm or perinuclear regions (images 1G and end 1H). Conclusion TMAO was able to induce the formation of EVs in endothelial cells, with characteristics morphological features. When compared to control EVs (image 1A), TMAO-EVs have a more heterogeneous size, which indicate a change in the size pattern, and thus the nature of the EVs induced by TMAO. TMAO-EVs were able to be internalized by human endothelial cells. This uptake can be closely related to the effects of EVs in endothelial cells, but more experiments need to be performed. Taken together, these data could contribute to understanding how the formation and uptake of TMAO-EVs by the endothelium occurs, relating their effects to the cardiovascular complications of CKD.

Metabolic Acidosis in CKD: Pathogenesis, Adverse Effects, and Treatment Effects.

Metabolic acidosis is a frequent complication of chronic kidney disease and is associated with a number of adverse outcomes, including worsening kidney function, poor musculoskeletal health, cardiovascular events, and death. Mechanisms that prevent metabolic acidosis detrimentally promote further kidney damage, creating a cycle between acid accumulation and acid-mediated kidney injury. Disrupting this cycle through the provision of alkali, most commonly using sodium bicarbonate, is hypothesized to preserve kidney function while also mitigating adverse effects of excess acid on bone and muscle. However, results from clinical trials have been conflicting. There is also significant interest to determine whether sodium bicarbonate might improve patient outcomes for those who do not have overt metabolic acidosis. Such individuals are hypothesized to be experiencing acid-mediated organ damage despite having a normal serum bicarbonate concentration, a state often referred to as subclinical metabolic acidosis. Results from small- to medium-sized trials in individuals with subclinical metabolic acidosis have also been inconclusive. Well-powered clinical trials to determine the efficacy and safety of sodium bicarbonate are necessary to determine if this intervention improves patient outcomes.