Chronic Kidney Disease as a Systemic Inflammatory Syndrome: Update on Mechanisms Involved and Potential Treatment

The relationship between dietary inflammatory index (DII) and early renal injury in population with/without hypertension: analysis of the National health and nutrition examination survey 2001-2002

BACKGROUND

Inflammation plays a crucial role in occurrence of kidney injury, and specific dietary patterns can influence systemic inflammation levels. However, the relationship between dietary inflammatory potential and early-stage kidney damage remains unclear.

METHOD

2,108 participants was recruited from 2001-2002 National Health and Nutrition Examination Survey (NHANES). Dietary Inflammatory Index (DII) is utilized to assess dietary inflammatory potential, calculated through a 24-h dietary recall questionnaire. Early renal injury was evaluated using urinary albumin to creatinine (UACR), cystatin C (CysC), β-2 microglobulin (β2M), and estimated glomerular filtration rate (eGFR) based on serum creatinine (eGFRs), cystatin C (eGFRc), and both Scr and CysC (eGFRs&c). Participant characteristics were analyzed, and association between DII, hypertension, and early renal injury markers was explored using multiple linear and logistic regression models.

RESULTS

The average age of participants was 53.9 years. DII exhibited a positive correlation with UACR (β = -0.048[0.017,0.078]), β2M (β = 0.019[0.010,0.027]), CysC (β = 0.012 [0.004,0.021]). Conversely, a negative correlation was observed between DII and eGFRc (β = -1.126[-1.554, -0.699]), eGFRs&c (β=-1.101[-1.653, -0.549]). A significant association was observed between hypertension and abnormality of early kidney damage markers. Subgroup analysis reveals that the positive correlation between DII and the occurrence of abnormal markers of early kidney damage is only observed in individuals with hypertension. Furthermore, an interaction between DII and hypertension was detected in eGFRs&c (OR:1.250[1.042, 1.499], p for interaction = 0.03).

CONCLUSION

Higher levels of DII may be associated with occurrence of early kidney damage. For individuals with hypertension, avoiding excessive consumption of pro-inflammatory foods may reduce the risk of renal injury.

Association between renal dysfunction and outcomes of lung cancer: A systematic review and meta‑analysis

Renal insufficiency and/or chronic kidney disease are common comorbidities in patients with lung cancer, potentially affecting their prognosis. The aim of the present study was to assess the existing evidence on the association between renal insufficiency (RI)/chronic kidney disease (CKD) and the overall survival (OS) and disease-free survival (DFS) of patients with lung cancer (LC). Comprehensive electronic searches in the PubMed, Embase and Scopus databases were performed for observational cohort and case-control studies and randomized controlled trials that investigated the association between RI/CKD and the OS and/or DFS of patients with LC. Random-effect models were used, and the combined effect sizes were reported as either standardized mean differences or relative risks, along with 95% confidence intervals (CI). A total of 10 studies were included. The duration of follow-up in the included studies ranged from 12 months to 5 years. Compared with patients with normal renal function, patients with LC with RI/CKD had worse OS rates [hazard ratio (HR), 1.38; 95% CI, 1.16-1.63] but similar DFS rates (HR, 1.12; 95% CI, 0.75-1.67) at follow-up. Subgroup analysis demonstrated a significant association between poor OS and RI/CKD in patients with stage I/II LC [HR, 1.76; 95% CI, 1.30-2.37] but not in patients with stage III/IV LC [HR, 1.18; 95% CI, 0.91, 1.54]. Furthermore, irrespective of the treatment modality i.e., surgery [HR, 1.78; 95% CI, 1.40-2.27] or medical management [HR, 1.37; 95% CI, 1.25-1.50], RI/CKD was notably associated with a poor OS at follow-up. The findings of the present study underscore the adverse impact of RI/CKD on the long-term survival of patients with LC.

Impaired Renal Function With Higher Remnant Cholesterol Related to Risk of Atherosclerotic Cardiovascular Disease: CGPS

BACKGROUND

Chronic kidney disease confers a high risk of atherosclerotic cardiovascular disease (ASCVD), partly due to hyperlipidemia. Although statins reduce the risk of ASCVD in chronic kidney disease, residual risk persists. We investigated whether higher remnant cholesterol is associated with an increased risk of ASCVD in statin users and nonusers with impaired renal function.

METHODS

We included 107 925 individuals from CGPS (Copenhagen General Population Study) initiated in 2003 to 2015, of whom 10 427 had impaired renal function (estimated glomerular filtration rate, <60 mL/min per 1.73 m2). Remnant cholesterol was calculated from a standard lipid profile. ASCVD was myocardial infarction, coronary heart disease death, ischemic stroke, coronary artery bypass graft, or percutaneous coronary intervention extracted from Danish nationwide health registries from baseline through 2018; individuals with events before the start of follow-up were excluded from relevant analysis.

RESULTS

In individuals with impaired renal function during up to 15 years of follow-up, 597 were diagnosed with myocardial infarction, 618 with ischemic stroke, and 1182 with ASCVD. In these individuals, a 1-mmol/L (39 mg/dL) higher remnant cholesterol level was associated with multivariable-adjusted hazard ratios of 1.21 (95% CI, 1.03-1.43) for myocardial infarction, 1.12 (95% CI, 0.93-1.34) for ischemic stroke, and 1.19 (95% CI, 1.05-1.35) for ASCVD. Corresponding hazard ratios for ASCVD were 1.36 (95% CI, 1.01-1.81) in statin users and 1.16 (95% CI, 1.01-1.33) in nonusers. Of the 1.36-fold excess risk of ASCVD in impaired versus normal renal function, elevated remnant cholesterol and elevated LDL (low-density lipoprotein) cholesterol explained 25% (95% CI, 2.5%-47%) and 0% in statin users and 8.3% (95% CI, 2.4%-14%) and 14% (95% CI, 6.4%-22%) in nonusers, respectively.

CONCLUSIONS

Our results suggest that higher remnant cholesterol is a good marker of increased risk of ASCVD in individuals with impaired renal function, while higher LDL cholesterol may not be. Patients with chronic kidney disease who have high levels of remnant cholesterol are identifiable through higher non-HDL (high-density lipoprotein) cholesterol or apoB levels.

Mediation analysis for TNF-α as a mediator between multiple metal exposure and kidney function

The association between metal mixtures and kidney function has been reported. However, reports on the mechanism of metal toxicity were limited. Oxidative stress was reported as a possible cause. This study aimed to determine the association between of kidney function and metals, such as arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), lead (Pb), selenium (Se), and zinc (Zn), and to explore the possible mediating role of tumor necrosis factor alpha (TNF-α) between metal toxicity and kidney function. In this study, we recruited 421 adults from a health examination. The concentration of blood metals was analyzed using inductively coupled plasma mass spectrometry. We used linear regression models to assess the association between metals and TNF-α. Then, mediation analysis was applied to investigate the relationship between metal exposure, TNF-α, and kidney function. In univariate linear regression, blood As, Cd, Co, Cu, Pb, and Zn levels significantly increased TNF-α and decreased kidney function. Higher blood As and Pb levels significantly increased TNF-α in multivariable linear regressions after adjusting for covariates. We found that blood levels of As (coefficients = -0.021, p = 0.011), Pb (coefficients = -0.060, p < 0.001), and Zn (coefficients = -0.230, p < 0.001) showed a significant negative association with eGFR in the multiple-metal model. Furthermore, mediation analysis showed that TNF-α mediated 41.7 %, 38.8 %, and 20.8 % of blood Cd, As and Pb, respectively. Among the essential elements, TNF-α mediated 24.5 %, 21.5 % and 19.9 % in the effects of blood Co, Cu, and Zn on kidney function, respectively. TNF-α, acting as a mediator, accounted for 20.1 % of the contribution between the WQS score of metal mixtures and the eGFR (p < 0.001). This study suggested that TNF-α may be a persuasive pathway mediating the association between metals and kidney function. Inflammation and kidney injury could be the underlying mechanisms of metal exposure. However, there is still a need to clarify the biochemical mechanism in follow-up studies.

Early use of SGLT2 inhibitors reduces the progression of diabetic kidney disease: a retrospective cohort study

OBJECTIVE

To evaluate the potential of sodium-glucose cotransporter 2 (SGLT2) inhibitors in preventing the progression of diabetic kidney disease and to provide guidance for clinical practice to improve renal health management strategies for diabetic patients.

METHODS

A retrospective analysis was conducted on 178 patients with diabetic kidney disease admitted to Baoji High Tech Hospital from March 2023 to March 2024. Of these, 88 patients who received early treatment with the SGLT2 inhibitor dapagliflozin were included in the early SGLT2-i group, while 90 patients receiving later treatment with SGLT2 inhibitor dapagliflozin were included in the late SGLT2-i group. Clinical data, overall effectiveness, adverse reactions, blood glucose, renal function, lipid levels, and inflammatory markers were compared between the two groups.

RESULTS

Prior to treatment, there were no differences in blood glucose indicators between the two groups (all P > 0.05). Following treatment, both groups showed reductions in 2-hour postprandial blood glucose (2hPG), fasting plasma glucose (FPG), and glycosylated hemoglobin (HbA1c), with the early SGLT2-i group demonstrating significantly lower values compared to the late SGLT2-i group (all P < 0.05). Similarly, there were no differences in renal function indicators between the two groups before treatment (all P > 0.05). However, following treatment, the early SGLT2-i group showed more noticeable improvements compared to the late SGLT2-i group (P < 0.05). Inflammatory markers and lipid levels followed similar patterns. The overall effectiveness of the early SGLT2-i group was higher than that of the late SGLT2-i group (92.05% vs. 78.89%, P < 0.05), while the incidence of adverse reactions did not differ statistically between the two groups (6.82% vs. 10.00%, P > 0.05).

CONCLUSION

Early use of SGLT2 inhibitors in diabetic kidney disease patients effectively controls blood glucose and lipid levels, improves renal function, reduces inflammatory responses, and exhibits a low incidence of adverse reactions. This demonstrates high safety and an important role in delaying disease progression. Therefore, it is worth considering clinical promotion and use for this patient population.

A Comprehensive Review of Biomarkers for Chronic Kidney Disease in Older Individuals: Current Perspectives and Future Directions

Chronic kidney disease (CKD) is a progressive condition characterized by a gradual loss of kidney function, leading to significant health complications and an increased risk of cardiovascular events. Early detection and effective management are crucial for slowing disease progression and improving patient outcomes. Biomarkers are valuable tools in CKD diagnosis, prognosis, and treatment. Traditional biomarkers, such as serum creatinine and urine protein, are widely used, but emerging biomarkers like cystatin C, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) offer enhanced diagnostic precision and insights into disease severity. These advanced biomarkers are particularly important in older adults, who may present with age-related physiological changes and comorbid conditions that complicate CKD management. This review explores the current state of biomarker research in CKD, focusing on their application in older populations. It highlights the role of traditional and emerging biomarkers, discusses their relevance for early detection and prognosis, and examines future directions in biomarker research, including technological innovations and personalized medicine approaches. By integrating biomarkers into clinical practice, healthcare providers can achieve more accurate diagnoses, tailor treatments to individual patient needs, and potentially improve the overall management of CKD. Continued research and development in this field are essential for addressing the complexities of CKD and advancing patient care.

GPCRs overexpression and impaired fMLP-induced functions in neutrophils from chronic kidney disease patients

Introduction

G-protein coupled receptors (GPCRs) expressed on neutrophils regulate their mobilization from the bone marrow into the blood, their half-live in the circulation, and their pro- and anti-inflammatory activities during inflammation. Chronic kidney disease (CKD) is associated with systemic inflammatory responses, and neutrophilia is a hallmark of CKD onset and progression. Nonetheless, the role of neutrophils in CKD is currently unclear.

Methods

Blood and renal tissue were collected from non-dialysis CKD (grade 3 - 5) patients to evaluate GPCR neutrophil expressions and functions in CKD development.

Results

CKD patients presented a higher blood neutrophil-to-lymphocyte ratio (NLR), which was inversely correlated with the glomerular filtration rate (eGFR). A higher frequency of neutrophils expressing the senescent GPCR receptor (CXCR4) and activation markers (CD18+CD11b+CD62L+) was detected in CKD patients. Moreover, CKD neutrophils expressed higher amounts of GPCR formyl peptide receptors (FPR) 1 and 2, known as neutrophil pro- and anti-inflammatory receptors, respectively. Cytoskeletal organization, migration, and production of reactive oxygen species (ROS) by CKD neutrophils were impaired in response to the FPR1 agonist (fMLP), despite the higher expression of FPR1. In addition, CKD neutrophils presented enhanced intracellular, but reduced membrane expression of the protein Annexin A1 (AnxA1), and an impaired ability to secrete it into the extracellular compartment. Secreted and phosphorylated AnxA1 is a recognized ligand of FPR2, pivotal in anti-inflammatory and efferocytosis effects. CKD renal tissue presented a low number of neutrophils, which were AnxA1+.

Conclusion

Together, these data highlight that CKD neutrophils overexpress GPCRs, which may contribute to an unbalanced aging process in the circulation, migration into inflamed tissues, and efferocytosis.

Innovative Treatments to Counteract Endothelial Dysfunction in Chronic Kidney Disease Patients

In chronic kidney disease (CKD) patients, several risk factors contribute to the development of endothelial dysfunction (ED), which can be described as an alteration in the cell structure or in the function of the endothelium. Among the well-known CKD-related risk factors capable of altering the production of endothelium-derived relaxing factors, we include asymmetric dimethylarginine increase, reduced dimethylarginine dimethylamine hydrolase enzyme activity, low-grade chronic systemic inflammation, hyperhomocysteinemia, oxidative stress, insulin resistance, alteration of calcium phosphorus metabolism, and early aging. In this review, we also examined the most important techniques useful for studying ED in humans, which are divided into indirect and direct methods. The direct study of coronary endothelial function is considered the gold standard technique to evaluate if ED is present. In addition to the discussion of the main pharmacological treatments useful to counteract ED in CKD patients (namely sodium-glucose cotransporter 2 inhibitors and mineralocorticoid receptor antagonist), we elucidate innovative non-pharmacological treatments that are successful in accompanying the pharmacological ones. Among them, the most important are the consumption of extra virgin olive oil with high intake of minor polar compounds, adherence to a plant-dominant, low-protein diet (LPD), an adaptive physical activity program and, finally, ketoanalogue administration in combination with the LPD or the very low-protein diet.

Associations of Kidney Functional Magnetic Resonance Imaging Biomarkers with Markers of Inflammation in Individuals with CKD

Key Points

Lower baseline apparent diffusion coefficient, indicative of greater cortical fibrosis, correlated with higher baseline concentrations of serum markers of inflammation. No association between baseline cortical R2* and baseline serum markers of inflammation were found. Baseline kidney functional magnetic resonance imaging biomarkers of fibrosis and oxygenation were not associated with changes in inflammatory markers over time, which may be due to small changes in kidney function in the study.

Background

Greater fibrosis and decreased oxygenation may amplify systemic inflammation, but data on the associations of kidney functional magnetic resonance imaging (fMRI) measurements of fibrosis (apparent diffusion coefficient [ADC]) and oxygenation (relaxation rate [R2*]) with systemic markers of inflammation are limited.

Methods

We evaluated associations of baseline kidney fMRI-derived ADC and R2* with baseline and follow-up serum IL-6 and C-reactive protein (CRP) in 127 participants from the CKD Optimal Management with Binders and NicotinamidE trial, a randomized, 12-month trial of nicotinamide and lanthanum carbonate versus placebo in individuals with CKD stages 3–4. Cross-sectional analyses of baseline kidney fMRI biomarkers and markers of inflammation used multivariable linear regression. Longitudinal analyses of baseline kidney fMRI biomarkers and change in markers of inflammation over time used linear mixed-effects models.

Results

Mean±SD eGFR, ADC, and R2* were 32.2±8.7 ml/min per 1.73 m2, 1.46±0.17×10−3 mm2/s, and 20.3±3.1 s−1, respectively. Median (interquartile range) IL-6 and CRP were 3.7 (2.4–4.9) pg/ml and 2.8 (1.2–6.3) mg/L, respectively. After multivariable adjustment, IL-6 and CRP were 13.1% and 27.3% higher per 1 SD decrease in baseline cortical ADC, respectively. Baseline cortical R2* did not have a significant association with IL-6 or CRP. Mean annual IL-6 and CRP slopes were 0.98 pg/ml per year and 0.91 mg/L per year, respectively. Baseline cortical ADC and R2* did not have significant associations with change in IL-6 or CRP over time.

Conclusions

Lower cortical ADC, suggestive of greater fibrosis, was associated with higher systemic inflammation. Baseline kidney fMRI biomarkers did not associate with changes in systemic markers of inflammation over time.

Effect of atherosclerosis on the relationship between atrial fibrillation and ischemic stroke incidence among patients on hemodialysis

In patients undergoing hemodialysis, the impact of atrial fibrillation (AF) through cardiac thromboembolism on the development of ischemic stroke may be influenced by the severity of atherosclerosis present. However, there are no large-scale reports confirming whether the severity of atherosclerosis influences the relationship between AF and stroke development in patients requiring hemodialysis. We aimed to investigate the effects of atherosclerotic disease on the relationship between AF and new-onset ischemic stroke. This nationwide longitudinal study based on dialysis facilities across Japan used data collected from the Japanese Renal Data Registry at the end of 2019 and 2020. The exposure was AF at the end of 2019, identified using a resting 12-lead electrocardiography. The primary outcome was the incidence of cerebral infarction (CI) after 1 year. To examine whether the number of atherosclerotic diseases modified the association between AF and the outcome, we estimated the odds ratios (ORs) using a logistic regression model and then assessed the presence of global interaction using Wald test. Following the study criteria, data from 151,350 patients (mean age, 69 years; men, 65.2%; diabetic patients, 48.7%) were included in the final analysis. A total of 9841 patients had AF (prevalence, 6.5%). Between 2019 and 2020, 4967 patients (3.2%) developed ischemic stroke. The adjusted OR of AF for new-onset CI was 1.5, which showed a decreasing trend with an increasing number of atherosclerotic diseases; the interaction was not significant (P = 0.34). While age, diabetes mellitus, smoking, systolic blood pressure, and serum C-reactive protein concentration were positively associated with CI, intradialytic weight gain, body mass index, and serum albumin level were negatively associated. While we demonstrated the association between AF and new-onset CI among Japanese patients on hemodialysis, we failed to demonstrate the evidence that the association was attenuated with an increasing numbers of atherosclerotic complications.

Exploring the association of metal mixture in blood to the kidney function and tumor necrosis factor alpha using machine learning methods

This research aimed to approach relationships between metal mixture in blood and kidney function, tumor necrosis factor alpha (TNF-α) by machine learning. Metals levels were measured by Inductively Couple Plasma Mass Spectrometry in blood from 421 participants. We applied K Nearest Neighbor (KNN), Naive Bayes classifier (NB), Support Vector Machines (SVM), random forest (RF), Gradient Boosting Decision Tree (GBDT), Categorical boosting (CatBoost), eXtreme Gradient Boosting (XGBoost), Whale Optimization-based XGBoost (WXGBoost) to identify the effect of plasma metals, TNF-α, and estimated glomerular filtration rate (eGFR by CKD-EPI equation). We conducted not only toxic metals, lead (Pb), arsenic (As), cadmium (Cd) but also included trace essential metals, selenium (Se), copper (Cu), zinc (Zn), cobalt (Co), to predict the interaction of TNF-α, TNF-α/white blood count, and eGFR. The high average TNF-α level group was observed among subjects with higher Pb, As, Cd, Cu, and Zn levels in blood. No associations were shown between the low and high TNF-α level group in blood Se and Co levels. Those with lower eGFR group had high Pb, As, Cd, Co, Cu, and Zn levels. The crucial predictor of TNF-α level in metals was blood Pb, and then Cd, As, Cu, Se, Zn and Co. The machine learning revealed that As was the major role among predictors of eGFR after feature selection. The levels of kidney function and TNF-α were modified by co-exposure metals. We were able to acquire highest accuracy of over 85% in the multi-metals exposure model. The higher Pb and Zn levels had strongest interaction with declined eGFR. In addition, As and Cd had synergistic with prediction model of TNF-α. We explored the potential of machine learning approaches for predicting health outcomes with multi-metal exposure. XGBoost model added SHAP could give an explicit explanation of individualized and precision risk prediction and insight of the interaction of key features in the multi-metal exposure.

Causal effects of systemic inflammatory regulators on chronic kidney diseases and renal function: a bidirectional Mendelian randomization study

Background

While targeted systemic inflammatory modulators show promise in preventing chronic kidney disease (CKD) progression, the causal link between specific inflammatory factors and CKD remains uncertain.

Methods

Using a genome-wide association study of 41 serum cytokines from 8,293 Finnish individuals, we conducted a bidirectional two-sample Mendelian randomization (MR) analysis. In addition, we genetically predicted causal associations between inflammatory factors and 5 phenotypes, including CKD, estimated glomerular filtration rate (eGFR), dialysis, rapid progression of CKD, and rapid decline in eGFR. Inverse variance weighting (IVW) served as the primary MR method, while MR-Egger, weighted median, and MR-pleiotropy residual sum and outlier (MR-PRESSO) were utilized for sensitivity analysis. Cochrane's Q test for heterogeneity. Leave-one-out method ensured stability of MR results, and Bonferroni correction assessed causal relationship strength.

Results

Seventeen cytokines were associated with diverse renal outcomes. Among them, after Bonferroni correction test, higher tumor necrosis factor alpha levels were associated with a rapid decrease in eGFR (OR = 1.064, 95% CI 1.028 - 1.103, P = 0.001), higher interleukin-4 levels were associated with an increase in eGFR (β = 0.003, 95% CI 0.001 - 0.005, P = 0.002), and higher growth regulated oncogene alpha (GROα) levels were associated with an increased risk of CKD (OR=1.035, 95% CI 1.012 - 1.058, P = 0.003). In contrast, genetic susceptibility to CKD was associated with an increase in GROa, and a decrease in eGFR may lead to an increase in stem cell factor. We did not find the presence of horizontal pleiotropy during the analysis.

Conclusion

We discovered causally related inflammatory factors that contribute to the initiation and progression of CKD at the genetic prediction level.

Disease-modifying interactions between chronic kidney disease and osteoarthritis: a new comorbid mouse model

OBJECTIVE

The prevalence of comorbid chronic kidney disease (CKD) and osteoarthritis (OA) is increasing globally. While sharing common risk factors, the mechanism and consequences of concurrent CKD-OA are unclear. The aims of the study were to develop a preclinical comorbid model, and to investigate the disease-modifying interactions.

METHODS

Seventy (70) male 8-10 week-old C57BL/6 mice were subjected to 5/6 nephrectomy (5/6Nx)±destabilisation of medial meniscus (DMM) or sham surgery. OA pathology and CKD were assessed 12 weeks postinduction by blinded histology scoring, micro-CT, immunohistochemistry for osteoclast and matrix metalloproteinase (MMP)-13 activity, and serum analysis of bone metabolic markers.

RESULTS

The 5/6Nx model recapitulated characteristic features of CKD, with renal fibrosis and deranged serum alkaline phosphatase, calcium and phosphate. There was no histological evidence of cartilage pathology induced by 5/6Nx alone, however, synovial MMP-13 expression and subchondral bone osteoclastic activity were increased (p<0.05), with accompanying reductions (p<0.05) in subchondral trabecular bone, bone volume and mineral density. DMM significantly (p<0.05) increased tibiofemoral cartilage damage, subchondral bone sclerosis, marginal osteophytes and synovitis, in association with increased cartilage and synovial MMP-13. DMM alone induced (p<0.05) renal fibrosis, proteinuria and increased (p<0.05) 5/6Nx-induced serum urea. However, DMM in 5/6Nx-mice resulted in significantly reduced (p<0.05) cartilage pathology and marginal osteophyte development, in association with reduced subchondral bone volume and density, and inhibition of 5/6Nx-induced subchondral bone osteoclast activation.

CONCLUSION

This study assessed a world-first preclinical comorbid CKD-OA model. Our findings demonstrate significant bidirectional disease-modifying interaction between CKD and OA.

Fibroblast Growth Factor 23 and Muscle Wasting: A Metabolic Point of View

Protein energy wasting (PEW), mostly characterized by decreased body stores of protein and energy sources, particularly in the skeletal muscle compartment, is highly prevalent in patients with moderate to advanced chronic kidney disease (CKD). Fibroblast growth factor 23 (FGF23) is an endocrine hormone secreted from bone and has systemic actions on skeletal muscle. In CKD, FGF23 is elevated and its coreceptor α-klotho is suppressed. Multiple lines of evidence suggest that FGF23 is interconnected with various mechanisms of skeletal muscle wasting in CKD, including systemic and local inflammation, exaggerated oxidative stress, insulin resistance (IR), and abnormalities in adipocytokine metabolism. Investigation of metabolic actions of FGF23 on muscle tissue could provide new insights into metabolic and nutritional abnormalities observed in patients with CKD.

Intrinsic TGF-β signaling attenuates proximal tubule mitochondrial injury and inflammation in chronic kidney disease

Excessive TGF-β signaling and mitochondrial dysfunction fuel chronic kidney disease (CKD) progression. However, inhibiting TGF-β failed to impede CKD in humans. The proximal tubule (PT), the most vulnerable renal segment, is packed with giant mitochondria and injured PT is pivotal in CKD progression. How TGF-β signaling affects PT mitochondria in CKD remained unknown. Here, we combine spatial transcriptomics and bulk RNAseq with biochemical analyses to depict the role of TGF-β signaling on PT mitochondrial homeostasis and tubulo-interstitial interactions in CKD. Male mice carrying specific deletion of Tgfbr2 in the PT have increased mitochondrial injury and exacerbated Th1 immune response in the aristolochic acid model of CKD, partly, through impaired complex I expression and mitochondrial quality control associated with a metabolic rewiring toward aerobic glycolysis in the PT cells. Injured S3T2 PT cells are identified as the main mediators of the maladaptive macrophage/dendritic cell activation in the absence of Tgfbr2. snRNAseq database analyses confirm decreased TGF-β receptors and a metabolic deregulation in the PT of CKD patients. This study describes the role of TGF-β signaling in PT mitochondrial homeostasis and inflammation in CKD, suggesting potential therapeutic targets that might be used to mitigate CKD progression.

Risk factors for heart, cerebrovascular, and kidney diseases: evaluation of potential side effects of medications to control hypertension, hyperglycemia, and hypercholesterolemia

Background

Heart disease (HD), cerebrovascular disease (CBD), and kidney disease (KD) are serious diseases worldwide. These diseases constitute the leading causes of death worldwide and are costly to treat. An analysis of risk factors is necessary to prevent these diseases.

Data and Methods

Risk factors were analyzed using data from 2,837,334, 2,864,874, and 2,870,262 medical checkups obtained from the JMDC Claims Database. The side effects of medications used to control hypertension (antihypertensive medications), hyperglycemia (antihyperglycemic medications), and hypercholesterolemia (cholesterol medications), including their interactions, were also evaluated. Logit models were used to calculate the odds ratios and confidence intervals. The sample period was from January 2005 to September 2019.

Results

Age and history of diseases were found to be very important factors, and the risk of having diseases could be almost doubled. Urine protein levels and recent large weight changes were also important factors for all three diseases and made the risks 10%-30% higher, except for KD. For KD, the risk was more than double for individuals with high urine protein levels. Negative side effects were observed with antihypertensive, antihyperglycemic, and cholesterol medications. In particular, when antihypertensive medications were used, the risks were almost doubled for HD and CBD. The risk would be triple for KD when individuals were taking antihypertensive medications. If they did not take antihypertensive medications and took other medications, these values were lower (20%-40% for HD, 50%-70% for CBD, and 60%-90% for KD). The interactions between the different types of medications were not very large. When antihypertensive and cholesterol medications were used simultaneously, the risk increased significantly in cases of HD and KD.

Conclusion

It is very important for individuals with risk factors to improve their physical condition for the prevention of these diseases. Taking antihypertensive, antihyperglycemic, and cholesterol medications, especially antihypertensive medications, may be serious risk factors. Special care and additional studies are necessary to prescribe these medications, particularly antihypertensive medications.

Limitations

No experimental interventions were performed. As the dataset was comprised of the results of health checkups of workers in Japan, individuals aged 76 and above were not included. Since the dataset only contained information obtained in Japan and the Japanese are ethnically homogeneous, potential ethnic effects on the diseases were not evaluated.

Chronic Kidney Disease Transdifferentiates Veins into a Specialized Immune-Endocrine Organ with Increased MYCN-AP1 Signaling

Most patients with end-stage renal disease (ESRD) and advanced chronic kidney disease (CKD) choose hemodialysis as their treatment of choice. Thus, upper-extremity veins provide a functioning arteriovenous access to reduce dependence on central venous catheters. However, it is unknown whether CKD reprograms the transcriptome of veins and primes them for arteriovenous fistula (AVF) failure. To examine this, we performed transcriptomic analyses of bulk RNA sequencing data of veins isolated from 48 CKD patients and 20 non-CKD controls and made the following findings: (1) CKD converts veins into immune organs by upregulating 13 cytokine and chemokine genes, and over 50 canonical and noncanonical secretome genes; (2) CKD increases innate immune responses by upregulating 12 innate immune response genes and 18 cell membrane protein genes for increased intercellular communication, such as CX3CR1 chemokine signaling; (3) CKD upregulates five endoplasmic reticulum protein-coding genes and three mitochondrial genes, impairing mitochondrial bioenergetics and inducing immunometabolic reprogramming; (4) CKD reprograms fibrogenic processes in veins by upregulating 20 fibroblast genes and 6 fibrogenic factors, priming the vein for AVF failure; (5) CKD reprograms numerous cell death and survival programs; (6) CKD reprograms protein kinase signal transduction pathways and upregulates SRPK3 and CHKB; and (7) CKD reprograms vein transcriptomes and upregulates MYCN, AP1, and 11 other transcription factors for embryonic organ development, positive regulation of developmental growth, and muscle structure development in veins. These results provide novel insights on the roles of veins as immune endocrine organs and the effect of CKD in upregulating secretomes and driving immune and vascular cell differentiation.

Th1-dominant cytokine responses in kidney patients after COVID-19 vaccination are associated with poor humoral responses

Cytokines are regulators of the immune response against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, the contribution of cytokine-secreting CD4⁺ and CD8⁺ memory T cells to the SARS-CoV-2-specific humoral immune response in immunocompromised kidney patients is unknown. Here, we profiled 12 cytokines after stimulation of whole blood obtained 28 days post second 100 μg mRNA-1273 vaccination with peptides covering the SARS-CoV-2 spike (S)-protein from patients with chronic kidney disease (CKD) stage 4/5, on dialysis, kidney transplant recipients (KTR), and healthy controls. Unsupervised hierarchical clustering analysis revealed two distinct vaccine-induced cytokine profiles. The first profile was characterized by high levels of T-helper (Th)₁ (IL-2, TNF-α, and IFN-γ) and Th₂ (IL-4, IL-5, IL-13) cytokines, and low levels of Th₁₇ (IL-17A, IL-22) and Th₉ (IL-9) cytokines. This cluster was dominated by patients with CKD, on dialysis, and healthy controls. In contrast, the second cytokine profile contained predominantly KTRs producing mainly Th₁ cytokines upon re-stimulation, with lower levels or absence of Th₂, Th₁₇, and Th₉ cytokines. Multivariate analyses indicated that a balanced memory T cell response with the production of Th₁ and Th₂ cytokines was associated with high levels of S1-specific binding and neutralizing antibodies mainly at 6 months after second vaccination. In conclusion, seroconversion is associated with the balanced production of cytokines by memory T cells. This emphasizes the importance of measuring multiple T cell cytokines to understand their influence on seroconversion and potentially gain more information about the protection induced by vaccine-induced memory T cells.

Dose- and time-dependent renoprotection of Angelica sinensis in patients with chronic kidney disease: A longitudinal cohort study

Background: Based on their anti-oxidative and anti-fibrotic properties, Angelica sinensis (Oliv.) Diels roots [Apiaceae; Radix Angelicae sinensis] (Danggui [abbreviated as S in the context]), Astragalus membranaceus (Fisch.) Bunge [Fabaceae; Astragalus membranaceus] (Huangqi [A]), Rheum palmatum L. [Polygonaceae; Rheum palmatum] (Dahuang [R]), and Salvia miltiorrhiza Bunge [Lamiaceae; Salvia miltiorrhiza Bunge radix et rhizoma] (Danshen [D]) are potential renoprotective Chinese herbal medicines (CHMs). Renoprotection using ARD alone for the treatment of chronic kidney disease (CKD) has been documented in pre-clinical, clinical, and meta-analysis research; however, only pre-clinical data are available for the use of S alone. Moreover, with an increasing number of CKD patients taking prescribed CHMs, hyperkalemia risk remains unclear. Methods: This study retrospectively analyzed national health insurance claims data in 2001-2017. Propensity score matching was used to analyze renal and survival outcomes and the dose-response effects of S without ARD use in 18,348 new S users, 9,174 new ARD users, and 36,696 non-users. Cox proportional hazard regression was used to investigate adjusted hazard ratios (aHRs) for end-stage renal disease (ESRD) in the presence of competing mortality and death. The additive effect of the S herb in single form to compounds was also analyzed. Additionally, to analyze hyperkalemia risk, an exact match on each covariate was used to include 42,265 new CHM users and non-users, while Poisson regression was used to estimate adjusted incidence rate ratios (aIRRs) of hyperkalemia of prescribed CHMs. Results: S users and ARD users were associated with aHRs of 0.77 (95% confidence interval; 0.69-0.86) and 1.04 (0.91-1.19), respectively, for ESRD and 0.55 (0.53-0.57) and 0.71 (0.67-0.75), respectively, for death. The renal and survival benefits of S use were consistent in several sensitivity analyses. The dose- and time-dependent renoprotection and dose-dependent survival benefits were observed for S use. The top two additive renoprotective collocations of the S herb in compounds were Xue-Fu-Zhu-Yu-Tang and Shen-Tong-Zhu-Yu-Tang, followed by Shu-Jing-Huo-Xue-Tang and Shen-Tong-Zhu-Yu-Tang. Moreover, CHM users were associated with aIRRs of 0.34 (0.31-0.37) for hyperkalemia. Conclusion: This study suggests dose- and time-dependent renoprotection and dose-dependent survival benefits of the S herb in compounds and no increased hyperkalemia risk of the prescribed CHMs in CKD patients.

The Onco-Nephrology Field: The Role of Personalized Chemotherapy to Prevent Kidney Damage

In recent years, the onco-nephrology field has acquired a relevant role in internal medicine due to the growing number of cases of renal dysfunction that have been observed in cancer patients. This clinical complication can be induced by the tumor itself (for example, due to obstructive phenomena affecting the excretory tract or by neoplastic dissemination) or by chemotherapy, as it is potentially nephrotoxic. Kidney damage can manifest as acute kidney injury or represent a worsening of pre-existing chronic kidney disease. In cancer patients, physicians should try to set preventive strategies to safeguard the renal function, avoiding the concomitant use of nephrotoxic drugs, personalizing the dose of chemotherapy according to the glomerular filtration rate (GFR) and using an appropriate hydration therapy in combination with nephroprotective compounds. To prevent renal dysfunction, a new possible tool useful in the field of onco-nephrology would be the development of a personalized algorithm for the patient based on body composition parameters, gender, nutritional status, GFR and genetic polymorphisms.

Untargeted Metabolomics by Ultra-High-Performance Liquid Chromatography Coupled with Electrospray Ionization-Quadrupole-Time of Flight-Mass Spectrometry Analysis Identifies a Specific Metabolomic Profile in Patients with Early Chronic Kidney Disease

Chronic kidney disease (CKD) has emerged as one of the most progressive diseases with increased mortality and morbidity. Metabolomics offers new insights into CKD pathogenesis and the discovery of new biomarkers for the early diagnosis of CKD. The aim of this cross-sectional study was to assess metabolomic profiling of serum and urine samples obtained from CKD patients. Untargeted metabolomics followed by multivariate and univariate analysis of blood and urine samples from 88 patients with CKD, staged by estimated glomerular filtration rate (eGFR), and 20 healthy control subjects was performed using ultra-high-performance liquid chromatography coupled with electrospray ionization-quadrupole-time of flight-mass spectrometry. Serum levels of Oleoyl glycine, alpha-lipoic acid, Propylthiouracil, and L-cysteine correlated directly with eGFR. Negative correlations were observed between serum 5-Hydroxyindoleacetic acid, Phenylalanine, Pyridoxamine, Cysteinyl glycine, Propenoylcarnitine, Uridine, and All-trans retinoic acid levels and eGFR. In urine samples, the majority of molecules were increased in patients with advanced CKD as compared with early CKD patients and controls. Amino acids, antioxidants, uremic toxins, acylcarnitines, and tryptophane metabolites were found in all CKD stages. Their dual variations in serum and urine may explain their impact on both glomerular and tubular structures, even in the early stages of CKD. Patients with CKD display a specific metabolomic profile. Since this paper represents a pilot study, future research is needed to confirm our findings that metabolites can serve as indicators of early CKD.

A Role of Sodium-Glucose Co-Transporter 2 in Cardiorenal Anemia Iron Deficiency Syndrome

Heart failure, renal dysfunction, anemia, and iron deficiency affect each other and form a vicious cycle, a condition referred to as cardiorenal anemia iron deficiency syndrome. The presence of diabetes further accelerates this vicious cycle. Surprisingly, simply inhibiting sodium-glucose co-transporter 2 (SGLT2), which is expressed almost exclusively in the proximal tubular epithelial cells of the kidney, not only increases glucose excretion into the urine and effectively controls blood glucose levels in diabetes but can also correct the vicious cycle of cardiorenal anemia iron deficiency syndrome. This review describes how SGLT2 is involved in energy metabolism regulation, hemodynamics (i.e., circulating blood volume and sympathetic nervous system activity), erythropoiesis, iron bioavailability, and inflammatory set points in diabetes, heart failure, and renal dysfunction.

TNFR2 as a Potential Biomarker for Early Detection and Progression of CKD

The inflammatory pathway driven by TNF-α, through its receptors TNFR1 and TNFR2, is a common feature in the pathogenesis of chronic kidney disease (CKD), regardless of the initial disease cause. Evidence correlates the chronic inflammatory status with decreased renal function. Our aim was to evaluate the potential of TNF receptors as biomarkers for CKD diagnosis and staging, as well as their association with the progression of renal lesions, in rat models of early and moderate CKD. We analyzed the circulating levels of inflammatory molecules—tumor necrosis factor-alpha (TNF-α), tumor necrosis factor receptor 1 (TNFR1) and 2 (TNFR2) and tissue inhibitor of metalloproteinase-1 (TIMP-1)—and studied their associations with TNFR1 and TNFR2 renal expression, glomerular and tubulointerstitial lesions, and with biomarkers of renal (dys)function. An increase in all inflammatory markers was observed in moderate CKD, as compared to controls, but only circulating levels of both TNFR1 and TNFR2 were significantly increased in the early disease; TNFR2 serum levels were negatively correlated with eGFR. However, only TNFR2 renal expression increased with CKD severity and showed correlations with the score of mild and advanced tubular lesions. Our findings suggest that renal TNFR2 plays a role in CKD development, and has potential to be used as a biomarker for the early detection and progression of the disease. Still, the potential value of this biomarker in disease progression warrants further investigation.

High dietary and lifestyle inflammatory scores are associated with increased risk of chronic kidney disease in Iranian adults

BACKGROUND

Systemic inflammation can be the initiator in developing chronic diseases that may be affected by the lifestyle and diet of individuals. In the current study, we aimed to assess the association of the inflammatory potential of diet and lifestyle, determined by the food-based index of dietary inflammatory potential (FBDI), dietary inflammation score (DIS), and lifestyle inflammation score (LIS), with risk of chronic kidney disease(CKD) in Iranian adults.

METHODS

A total of 6044 CKD-free individuals aged ≥ 18 years, were recruited from among participants of the Tehran Lipid and Glucose Study(surveys 3 and 4) and followed a mean of 6.03 years(follow-up rate:94.95%). Data on dietary intakes were determined using a food frequency questionnaire. The inflammatory potential of diet and lifestyle were determined based on three indices, including FBDI, DIS, and LIS. Using the National Kidney Foundation guidelines, we defined CKD as eGFR < 60 mL/min/1.73 m².

RESULTS

Mean ± SD age of the study population(54.3% women) was 37.8 ± 12.8 years. We identified 1216(20.1%) new cases of CKD during the 6.03 years of follow-up (46,889.8 person-years). In the multivariable-adjusted model, the risk of CKD incident is increased across quartiles of FBDI (HR = 1.21;95%CI:1.03-1.42, P_trend:0.014) and LIS (HR = 1.28;95%CI:1.07-1.55,P_trend:0.006). However, no significant relationship was observed between the higher DIS score and CKD risk.

CONCLUSION

Our findings showed that a higher inflammatory potential of diet and lifestyle, characterized by a higher score of FBDI and LIS, was related to increased incidence of CKD, while no significant relationship was reported between the DIS score and CKD incident.

Cinnamon: an aromatic condiment applicable to chronic kidney disease

Cinnamon, a member of the Lauraceae family, has been widely used as a spice and traditional herbal medicine for centuries and has shown beneficial effects in cardiovascular disease, obesity, and diabetes. However, its effectiveness as a therapeutic intervention for chronic kidney disease (CKD) remains unproven. The bioactive compounds within cinnamon, such as cinnamaldehyde, cinnamic acid, and cinnamate, can mitigate oxidative stress, inflammation, hyperglycemia, gut dysbiosis, and dyslipidemia, which are common complications in patients with CKD. In this narrative review, we assess the mechanisms by which cinnamon may alleviate complications observed in CKD and the possible role of this spice as an additional nutritional strategy for this patient group.

An updated clinical prediction model of protein-energy wasting for hemodialysis patients

Background and aim

Protein-energy wasting (PEW) is critically associated with the reduced quality of life and poor prognosis of hemodialysis patients. However, the diagnosis criteria of PEW are complex, characterized by difficulty in estimating dietary intake and assessing muscle mass loss objectively. We performed a cross-sectional study in hemodialysis patients to propose a novel PEW prediction model.

Materials and methods

A total of 380 patients who underwent maintenance hemodialysis were enrolled in this cross-sectional study. The data were analyzed with univariate and multivariable logistic regression to identify influencing factors of PEW. The PEW prediction model was presented as a nomogram by using the results of logistic regression. Furthermore, receiver operating characteristic (ROC) and decision curve analysis (DCA) were used to test the prediction and discrimination ability of the novel model.

Results

Binary logistic regression was used to identify four independent influencing factors, namely, sex (P = 0.03), triglycerides (P = 0.009), vitamin D (P = 0.029), and NT-proBNP (P = 0.029). The nomogram was applied to display the value of each influencing factor contributed to PEW. Then, we built a novel prediction model of PEW (model 3) by combining these four independent variables with part of the International Society of Renal Nutrition and Metabolism (ISRNM) diagnostic criteria including albumin, total cholesterol, and BMI, while the ISRNM diagnostic criteria served as model 1 and model 2. ROC analysis of model 3 showed that the area under the curve was 0.851 (95%CI: 0.799-0.904), and there was no significant difference between model 3 and model 1 or model 2 (all P > 0.05). DCA revealed that the novel prediction model resulted in clinical net benefit as well as the other two models.

Conclusion

In this research, we proposed a novel PEW prediction model, which could effectively identify PEW in hemodialysis patients and was more convenient and objective than traditional diagnostic criteria.

Association of the nutritional risk index for Japanese hemodialysis with mortality and dietary nutritional intake in patients undergoing hemodialysis during long-term hospitalization

AIM

The nutritional risk index for Japanese hemodialysis (NRI-JH) is a nutritional screening tool for predicting mortality in patients undergoing hemodialysis; however, its utility in patients undergoing hemodialysis during long-term hospitalization who have a high risk of protein-energy wasting, is unclear.

METHODS

This retrospective study assessed hospitalized patients undergoing hemodialysis during long-term care at a single hospital. The NRI-JH was calculated using body mass index, serum albumin level, total cholesterol level, and serum creatinine level. The patients were categorized into three risk groups-low, medium, and high. Dietary energy and protein intake were evaluated by dietitians. The association of NRI-JH risk with nutritional intake and mortality were examined.

RESULTS

In total, 133 patients were analyzed. The NRI-JH risk was low in 24%, medium in 26%, and high in 50% of the patients. The patients in the high-risk group were older and had lower energy and protein intakes than those in the low- and medium-risk groups. High-risk patients showed shorter survival times than low- and medium-risk patients, and a high NRI-JH risk was associated with a high mortality rate (hazard ratio [HR], 2.12; 95% confidence interval [CI], 1.08-4.77; p < 0.05). The association weakened when protein intake and C-reactive protein level were added as covariates (HR, 2.01; 95% CI, 0.95-4.28, p = 0.07).

CONCLUSIONS

High NRI-JH risk was associated with low dietary nutritional intake and poor survival in patients undergoing hemodialysis during long-term hospitalization. Nutritional status evaluation and nutritional interventions may improve prognosis in this population.

Association of Albumin and Globulin with Mortality Risk in Incident Peritoneal Dialysis Patients

Background: Nutrition and inflammation have been implicated in predicting mortality in patients on peritoneal dialysis (PD). Serum albumin and globulin can be regarded for the nutritional and inflammatory status. However, there is lack of data to evaluate the synergistic effect of albumin and globulin on mortality prediction. Methods: In 554 patients initiating PD from January 2001 to July 2016, we divided them into four groups by the combination of two categories of low vs. high albumin and low vs. high globulin. The median values for albumin and globulin were chosen to classify them into low or high groups. Their associations with all-cause and cardiovascular (CV) mortality were examined in Cox regression models adjusted for confounding clinical and laboratory data. Results: Patients, 52.91 ± 15.2 years old and 47.8% men, had a median (interquartile range) value of 3.3 (2.9−3.8) g/dL for albumin and 2.8 (2.5−3.2) g/dL for globulin, respectively. Patients with low albumin and high globulin had the highest all-cause mortality and CV mortality, with adjusted hazard ratios of 3.87 (95% CI 1.83−8.20, p < 0.001) and 5.65 (95% CI 2.23−14.34, p < 0.001), respectively, compared with those with a high albumin and low globulin having the lowest mortality rate. Sensitivity analyses further confirmed this relationship. Conclusions: A patient profile of either low albumin or high globulin is linked to a higher risk for mortality, particularly for a profile of both low albumin and high globulin compared with one without either of them. Further studies are needed to explore the mechanisms underlying this phenomenon and how to improve clinical outcomes in those high-risk patients.

Metals and Metallothionein Expression in Relation to Progression of Chronic Kidney Disease of Unknown Etiology (CKDu) in Sri Lanka

Chronic kidney disease of unknown etiology was investigated for metal relations in an endemic area by a cross-sectional study with CKD stages G1, G2, G3a, G3b, G4, G5 (ESRD), and endemic and nonendemic controls (EC and NEC) as groups. Subjects with the medical diagnosis were classified into groups by eGFR (SCr, CKD-EPI) and UACR of the study. It determined 24 metals/metalloids in plasma (ICPMS) and metallothionein (MT) mRNA in blood (RT-PCR). MT1A at G3b and MT2A throughout G2−G5 showed increased transcription compared to NEC (ANOVA, p < 0.01). Both MT1A and MT2A remained metal-responsive as associations emerged between MT2A and human MT inducer Cr (in EC: r = 0.54, p < 0.05, n = 14), and between MT1A and MT2A (in EC pooled with G1−G5: r = 0.58, p < 0.001, n = 110). Human MT (hMT)-inducers, namely Zn, Cu, As, Pb, and Ni; Σ hMT-inducers; 14 more non-inducer metals; and Σ MT-binding metals remained higher (p < 0.05) in EC as compared to NEC. Declining eGFR or CKD progression increased the burden of Be, Mg, Al, V, Co, Ni, Rb, Cs, Ba, Mn, Zn, Sr, Σ hMT-inducers, and Σ MT-binding metals in plasma, suggesting an MT role in the disease. MT1A/2A mRNA followed UACR (PCA, Dendrogram: similarity, 57.7%). The study provides evidence that proteinuric chronic renal failure may increase plasma metal levels where blood MT2A could be a marker.

Muscle Wasting in Chronic Kidney Disease: Mechanism and Clinical Implications—A Narrative Review

Muscle wasting, known to develop in patients with chronic kidney disease (CKD), is a deleterious consequence of numerous complications associated with deteriorated renal function. Muscle wasting in CKD mainly involves dysregulated muscle protein metabolism and impaired muscle cell regeneration. In this narrative review, we discuss the cardinal role of the insulin-like growth factor 1 and myostatin signaling pathways, which have been extensively investigated using animal and human studies, as well as the emerging concepts in microRNA- and gut microbiota-mediated regulation of muscle mass and myogenesis. To ameliorate muscle loss, therapeutic strategies, including nutritional support, exercise programs, pharmacological interventions, and physical modalities, are being increasingly developed based on advances in understanding its underlying pathophysiology.

Dietary Inflammatory Potential Is Associated With Sarcopenia Among Chronic Kidney Disease Population

Background

Sarcopenia, characterized by impaired muscle mass and function, is a common complication and the main reason for bad life quality and high mortality in chronic kidney disease (CKD). Limiting systemic inflammation is a potable intervention for sarcopenia. Dietary inflammatory potential can influence systemic inflammation. However, research about the association between dietary inflammatory potential and sarcopenia in CKD is limited.

Aim

To investigate the association between dietary inflammatory potential and sarcopenia in the CKD population.

Methods

We conducted a cross-section study based on the public database of the National Health and Nutrition Examination Survey (NHANES). In total, 2,569 adult CKD participants who had complete data for dietary inflammatory potential and sarcopenia were included. The dietary inflammatory potential was calculated by the dietary inflammation index (DII) score based on dietary recall interviews. We assessed sarcopenia via low skeletal muscle mass measured by dual-energy X-ray absorptiometry. Smooth curve fitting and a generalized linear mixed model were used to evaluate the relationship between DII and sarcopenia. Moreover, subgroup and sensitivity analyses were performed.

Results

The overall prevalence of sarcopenia among patients with CKD is 19.11%. Smooth curve fitting results displayed that the DII score is near-linear positively associated with sarcopenia. Logistic regression confirmed sarcopenia is independently related to DII scores (odds ratio [OR], 1.17; 95% CI, 1.06–1.29). Subgroup analyses revealed relatively stronger associations between DII and sarcopenia among patients with CKD with other sarcopenia risk factors, such as hypoalbuminemia, low energy intake, low protein intake, and comorbidities.

Conclusion

The dietary inflammatory potential is independently related to sarcopenia among patients with CKD. Anti-inflammatory diet patterns may be a protective intervention for CKD-associated sarcopenia.

The Signaling Pathway of TNF Receptors: Linking Animal Models of Renal Disease to Human CKD

Chronic kidney disease (CKD) has been recognized as a global public health problem. Despite the current advances in medicine, CKD-associated morbidity and mortality remain unacceptably high. Several studies have highlighted the contribution of inflammation and inflammatory mediators to the development and/or progression of CKD, such as tumor necrosis factor (TNF)-related biomarkers. The inflammation pathway driven by TNF-α, through TNF receptors 1 (TNFR1) and 2 (TNFR2), involves important mediators in the pathogenesis of CKD. Circulating levels of TNFRs were associated with changes in other biomarkers of kidney function and injury, and were described as predictors of disease progression, cardiovascular morbidity, and mortality in several cohorts of patients. Experimental studies describe the possible downstream signaling pathways induced upon TNFR activation and the resulting biological responses. This review will focus on the available data on TNFR1 and TNFR2, and illustrates their contributions to the pathophysiology of kidney diseases, their cellular and molecular roles, as well as their potential as CKD biomarkers. The emerging evidence shows that TNF receptors could act as biomarkers of renal damage and as mediators of the disease. Furthermore, it has been suggested that these biomarkers could significantly improve the discrimination of clinical CKD prognostic models.

Neuroimmunoendocrine Link Between Chronic Kidney Disease and Olfactory Deficits

Chronic kidney disease (CKD) is a multifactorial pathology that progressively leads to the deterioration of metabolic functions and results from deficient glomerular filtration and electrolyte imbalance. Its economic impact on public health is challenging. Mexico has a high prevalence of CKD that is strongly associated with some of the most common metabolic disorders like diabetes and hypertension. The gradual loss of kidney functions provokes an inflammatory state and endocrine alterations affecting several systems. High serum levels of prolactin have been associated with CKD progression, inflammation, and olfactory function. Also, the nutritional status is altered due to impaired renal function. The decrease in calorie and protein intake is often accompanied by malnutrition, which can be severe at advanced stages of the disease. Nutrition and olfactory functioning are closely interconnected, and CKD patients often complain of olfactory deficits, which ultimately can lead to deficient food intake. CKD patients present a wide range of deficits in olfaction like odor discrimination, identification, and detection threshold. The chronic inflammatory status in CKD damages the olfactory epithelium leading to deficiencies in the chemical detection of odor molecules. Additionally, the decline in cognitive functioning impairs the capacity of odor differentiation. It is not clear whether peritoneal dialysis and hemodialysis improve the olfactory deficits, but renal transplants have a strong positive effect. In the present review, we discuss whether the olfactory deficiencies caused by CKD are the result of the induced inflammatory state, the hyperprolactinemia, or a combination of both.

Anti-inflammatory response to curcumin supplementation in chronic kidney disease and hemodialysis patients: A systematic review and meta-analysis

Objective

This study was designed to determine the association curcumin has on pro-inflammatory biomarkers in patients with chronic kidney disease (CKD (and in those receiving hemodialysis (HD).

Materials and Methods

This meta-analysis was undertaken following PRISMA guidelines. An extensive systematic review was undertaken until 10/11/2021 using PubMed, Web of Science (ISI), and Scopus databases. The standardized mean difference (SMD) and 95% confidence intervals (CI) were used to estimate the overall effect size of curcumin on serum high-sensitivity C-reactive protein (hs-CRP), and pro-inflammatory cytokines including interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) in patients with CKD and those receiving HD.

Results

Overall, ten randomized controlled trials (RCTs) comprising 523 patients were incorporated into the systematic review and meta-analysis. The results showed that when compared with control groups, there was no significant effect observed linking curcumin and IL-6 (SMD = 0.24%, 95% CI = -0.14 to 0.62, p = 0.221), TNF-α (SMD = 0.11%, 95% CI = -0.19 to 0.40, p = 0.480) or hs-CRP (SMD = -0.17%, 95% CI = -0.36 to 0.03, p = 0.093). The analysis determined no publication bias related to the influence of curcumin on IL-6, TNF-α or acute phase reactant, hs-CRP. The Egger's and Begg's test results were not statistically significant (p˃0.20).

Conclusion

In patients with CKD and those receiving HD, the use of curcumin supplementation has no statistically significant effect on the anti-inflammatory biomarkers reviewed in this study.

Cholemic Nephropathy as Cause of Acute and Chronic Kidney Disease. Update on an Under-Diagnosed Disease

Cholemic nephropathy (CN) is a recognized cause of acute kidney injury (AKI) in patients with severe hyperbilirubinemia (sHyb) and jaundice. Pathophysiological mechanisms of CN are not completely understood, but it seems caused both by direct toxicity of cholephiles and bile casts formation in nephrons enhanced by prolonged exposure to sHyb, particularly in the presence of promoting factors, as highlighted by a literature reviewed and by personal experience. The aim of our update is to retrace CN in its pathophysiology, risk factors, diagnosis and treatment, underlining the role of sHyb, promoting factors, and CN-AKI diagnostic criteria in the different clinical settings associated with this often-concealed disease. Our purpose is to focus on clinical manifestation of CN, exploring the possible transition to CKD. Cholemic nephropathy is an overlooked clinical entity that enters differential diagnosis with other causes of AKI. Early diagnosis and treatment are essential because renal injury could be fully reversible as rapidly as bilirubin levels are reduced. In conclusion, our proposal is to introduce an alert for considering CN in diagnostic and prognostic scores that include bilirubin and/or creatinine with acute renal involvement, with the aim of early diagnosis and treatment of sHyb to reduce the burden on renal outcome.

Follistatin-Like-1 (FSTL1) Is a Fibroblast-Derived Growth Factor That Contributes to Progression of Chronic Kidney Disease

Our understanding of the mechanisms responsible for the progression of chronic kidney disease (CKD) is incomplete. Microarray analysis of kidneys at 4 and 7 weeks of age in Col4a3^-/- mice, a model of progressive nephropathy characterized by proteinuria, interstitial fibrosis, and inflammation, revealed that Follistatin-like-1 (Fstl1) was one of only four genes significantly overexpressed at 4 weeks of age. mRNA levels for the Fstl1 receptors, Tlr4 and Dip2a, increased in both Col4a^-/- mice and mice subjected to unilateral ureteral obstruction (UUO). RNAscope^® (Advanced Cell Diagnostics, Newark CA, USA) localized Fstl1 to interstitial cells, and in silico analysis of single cell transcriptomic data from human kidneys showed Fstl1 confined to interstitial fibroblasts/myofibroblasts. In vitro, FSTL1 activated AP1 and NFκB, increased collagen I (COL1A1) and interleukin-6 (IL6) expression, and induced apoptosis in cultured kidney cells. FSTL1 expression in the NEPTUNE cohort of humans with focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), and IgA nephropathy (IgAN) was positively associated with age, eGFR, and proteinuria by multiple linear regression, as well as with interstitial fibrosis and tubular atrophy. Clinical disease progression, defined as dialysis or a 40 percent reduction in eGFR, was greater in patients with high baseline FSTL1 mRNA levels. FSTL1 is a fibroblast-derived cytokine linked to the progression of experimental and clinical CKD.