The Growing Epidemic of Chronic Kidney Disease: Preventive Strategies to Delay the Risk for Progression to ESRD

Exploring the Link between Oxidative Stress, Selenium Levels, and Obesity in Youth

Obesity is a worldwide increasing concern. Although in adults this is easily estimated with the body mass index, in children, who are constantly growing and whose bodies are changing, the reference points to assess weight status are age and gender, and need corroboration with complementary data, making their quantification highly difficult. The present review explores the interaction spectrum of oxidative stress, selenium status, and obesity in children and adolescents. Any factor related to oxidative stress that triggers obesity and, conversely, obesity that induces oxidative stress are part of a vicious circle, a complex chain of mechanisms that derive from each other and reinforce each other with serious health consequences. Selenium and its compounds exhibit key antioxidant activity and also have a significant role in the nutritional evaluation of obese children. The balance of selenium intake, retention, and metabolism emerges as a vital aspect of health, reflecting the complex interactions between diet, oxidative stress, and obesity. Understanding whether selenium status is a contributor to or a consequence of obesity could inform nutritional interventions and public health strategies aimed at preventing and managing obesity from an early age.

Targeted inhibition of ZAK ameliorates renal interstitial fibrosis

ZAK (sterile alpha motif and leucine zipper-containing kinase) is a newly discovered member of the subfamily of mitogen-activated protein kinase kinase kinases (MAP3Ks). The role of ZAK in kidney disease remains largely unknown. In this study, we systematically investigated the expression and function of ZAK in the progression of tubulointerstitial fibrosis (TIF). ZAK was induced, predominantly in tubular epithelium, in both fibrotic kidneys of human and mouse models with TIF. ZAK expression level was correlated with the extent of renal fibrosis and the decline of eGFR of CKD patients. Depleting ZAK attenuated TIF and inflammation induced by unilateral ureteral occlusion (UUO) together with decreased activation of p38 MAPK and Smads signaling. Moreover, we demonstrated that overexpressed ZAK was in complex with Smad2/3 and TGF-β receptor Ⅰ (TβRI). Whereas, silencing endogenous ZAK ameliorated the amount of Smad2/3 recruited to TβRI. Moreover, we discovered a novel small molecule inhibitor of ZAK, named 6p. In vitro, incubation with 6p inhibited TGF-β1-induced fibrogenic response in NRK52E cells. In vivo, intragastric administration of 6p ameliorated TIF and inflammation in UUO and unilateral ischemia-reperfusion injury model. Delayed administration of 6p was also effective in retarding the progression of the established TIF. In conclusion, ZAK is a novel therapeutic target for TIF, and 6p might be a potential therapeutic agent for TIF.

Serum uric acid level and all-cause and cardiovascular mortality in peritoneal dialysis patients: A systematic review and dose-response meta-analysis of cohort studies

BACKGROUND

The association between serum uric acid (SUA) and all-cause and cardiovascular disease (CVD) mortality in peritoneal dialysis (PD) patients is controversial. Therefore, we aimed to determine the relationship between SUA and all-cause and CVD mortality in PD patients.

METHOD

Web of Science, EMBASE, PubMed and the Cochrane Library databases were searched from their inception to 7 April 2021. Effect estimates were presented as hazard ratios (HRs) with 95% confidence intervals (95% CIs) and pooled using random effects model.

RESULT

Thirteen cohort studies with 22418 patients were included in this systematic review, of which 9 were included in the meta-analysis. Before switching the reference group, pooled result for the highest SUA category was significantly greater than the median for all-cause mortality (HR = 2.41, 95% CI: 1.37-4.26). After switching the reference group, the highest SUA category did not demonstrate an increased all-cause (HR = 1.40, 95% CI: 0.95-2.05) or CVD (HR = 1.30, 95% CI: 0.72-2.34) mortality compared with the lowest SUA category. Dose-response analysis suggested a nonlinear association between SUA and all-cause mortality risk (Pnonlinearity = 0.002).

CONCLUSION

This meta-analysis didn't find the relationship between SUA levels and all-cause and CVD mortality risk in PD patients. More rigorously designed studies are warranted in the future.

Long-term cardiometabolic consequences among adolescent offspring born to women with type1 diabetes

AIM

The aim of this study was to compare cardiometabolic measures between adolescents born to women with and without type1diabetes.

METHODS

In this cross-sectional study, 103 adolescents (51 males) aged 14-19 years, born to women with type1diabetes were enrolled in the study. Body mass index, blood pressure, urine microalbumin to creatinine ratio, hemoglobin A1c, serum urate, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, and estimated glomerular filtration rate (eGFR) were measured in all. The results were compared with 98 adolescents born to non-diabetic women.

RESULTS

In multiple linear regression models, adolescent offspring of women with type 1 diabetes had significantly higher blood pressure (Odds ratio [OR] 2·45; 95% Confidence interval [CI] 2.1-2.8, hypertension (OR 2.52; 95% CI 1.99-3.01), body mass index (OR 2.22; 95% CI: 1.76-2.69), elevated total cholesterol (OR 1.5; 95% CI 0.2-2.9), low-density lipoprotein cholesterol (OR·33; 95% CI 1.06-1.64), triglyceride (OR 1.34; 95% CI: 1.05-1.70), eGFR (OR 0.96 ;95% CI 0.81-1.11) and microlabuminuria (OR 1.1; 95% CI: 0.87-1.12) compared to offspring of women without diabetes.

CONCLUSION

The study demonstrates a strong correlation between maternal exposure to type1diabetes and higher risk of developing obesity, hypertension, dyslipidemia, eGFR, and microalbumiuria in the adolescent offspring.

Obesity and chronic kidney disease: prevalence, mechanism, and management

The prevalence of childhood obesity is increasing worldwide at an alarming rate. While obesity is known to increase a variety of cardiovascular and metabolic diseases, it also acts as a risk factor for the development and progression of chronic kidney disease (CKD). During childhood and adolescence, severe obesity is associated with an increased prevalence and incidence of the early stages of kidney disease. Importantly, children born to obese mothers are also at increased risk of developing obesity and CKD later in life. The potential mechanisms underlying the association between obesity and CKD include hemodynamic factors, metabolic effects, and lipid nephrotoxicity. Weight reduction via increased physical activity, caloric restriction, treatment with angiotensin-converting enzyme inhibitors, and judicious bariatric surgery can be used to control obesity and obesity-related kidney disease. Preventive strategies to halt the obesity epidemic in the healthcare community are needed to reduce the widespread deleterious consequences of obesity including CKD development and progression.

Alpha-1 Acid Glycoprotein and Podocin mRNA as Novel Biomarkers for Early Glomerular Injury in Obese Children

Introduction: Obesity, which is a serious problem in children, has a negative impact on many organs, including kidneys, and obesity-related glomerulopathy (ORG) is an increasingly common cause of ESKD (end-stage kidney disease) in adults. Early-detected and -treated glomerular lesions are reversible, so it is important to find a useful marker of early damage. The study aimed to evaluate the albumin-to-creatinine ratio (ACR), urinary alpha-1-acid glycoprotein (α1-AGP), and mRNA of podocyte-specific proteins as indicators of glomerular injury and their relationship with the degree of obesity and metabolic disorders. Materials and Methods: A total of 125 obese children and 33 healthy peers were enrolled. Patients were divided into two groups, depending on SDS BMI values. ACR, α1-AGP, mRNA expression of nephrin, synaptopodin, podocin, and C2AP protein in urine sediment were measured. Results: ACR values did not differ between groups and were within the normal range. α1-AGP and mRNA expression were significantly higher in obese children compared with controls. mRNA expression of the remaining podocyte proteins was similar in both groups. No significant differences concerning all examined parameters were found depending on the degree of obesity. There was a positive significant correlation between α1-AGP and ACR. Conclusions: Increased α1-AGP before the onset of albuminuria suggests its usefulness as a biomarker of early glomerular damage in obese children. An increased podocin mRNA expression also indicates podocyte damage and may be linked to ORG development. The lack of increase in expression of other podocyte proteins suggests that podocin mRNA may be a more specific and sensitive biomarker. The degree of obesity has no impact on the tested parameters, but further studies are needed to confirm it.

Risk of Kidney Failure in Patients With Cancer: A South Korean Population-Based Cohort Study

RATIONALE & OBJECTIVE

Reduced kidney function is associated with an increased risk of cancer; however, it is unclear if cancer increases the risk of kidney failure with replacement therapy (KFRT). We assessed the risk of KFRT among patients with various types of cancer collectively and with specific types of cancer.

STUDY DESIGN

Retrospective population-based cohort study.

SETTING & PARTICIPANTS

A total of 2,473,095 participants with (n = 824,365) or without (n = 1,648,730) cancer registered in the Korean National Health Insurance Service database.

PREDICTORS

Cancer and cancer subtypes defined using International Classification of Diseases, 10th Revision, Clinical Modification, codes.

OUTCOMES

Primary outcome was KFRT defined as the initiation of hemodialysis or peritoneal dialysis or kidney transplantation.

ANALYTICAL APPROACH

For each patient with cancer, 2 controls matched for age, sex, estimated glomerular filtration rate, diabetes, and hypertension were included. To address the competing risk of death, a competing risk survival analysis was conducted using the Fine and Gray method.

RESULTS

Occurrence of KFRT was higher in patients with cancer than in controls without cancer (incidence rates of 1.07 vs 0.51 cases per 1,000 person-years). Competing risk analysis showed that cancer was significantly associated with an increased risk of KFRT after adjusting for other potential predictors (adjusted hazard ratio, 2.29 [95% CI, 2.20-2.39]). Multiple myeloma, leukemia, lymphoma, and kidney, ovarian, and liver cancer were most significantly associated with an increased KFRT risk, with multiple myeloma conferring the highest risk across age and sex groups. All subgroups of patients with cancer (based on age, sex, smoking, alcohol, exercise, obesity, and comorbid conditions) exhibited a higher risk of KFRT.

LIMITATIONS

Causal association between cancer and kidney outcomes could not be confirmed.

CONCLUSIONS

Patients with cancer, particularly those with multiple myeloma, exhibited an increased risk of KFRT after accounting for the competing risk of death.

Perceived barriers and facilitators to chronic kidney disease care among patients in Singapore: a qualitative study

OBJECTIVE

To outline the facilitators and barriers to patients' self-management of predialysis chronic kidney disease (CKD).

DESIGN

Qualitative.

SETTING

Three polyclinics in a public primary care institution in Singapore.

PARTICIPANTS

20 patients entered and completed the study. Inclusion criteria were: (1) English speaking, (2) aged 40 years and above, (3) identified by clinical coding as 'DM (diabetes mellitus) nephropathy-overt' and 'DM nephropathy-incipient', by their physicians in the polyclinic, with an estimated glomerular filtration rate of less than 60 mL/min/1.73 m² (based on electronic health records) and (4) aware of their CKD illness. Exclusion criteria were: (1) receiving dialysis or had received a kidney transplant, (2) suffered from any visual, auditory or cognitive impairment which could hinder their ability to participate in the study or (3) pregnant.

RESULTS

We found that the major barriers to CKD management were a lack of knowledge and awareness of CKD, a passive attitude toward self-management and insufficient patient-physician communication. Major facilitators included patient trust and satisfaction with the physician and family support. Many patients reported that there was an overload of information and too little guidance on how to manage their condition, especially regarding dietary recommendations.

CONCLUSION

We identified several barriers and facilitators to the management of predialysis CKD among patients. A multi-pronged approach for raising CKD awareness is required: improving patient-physician communication, implementing CKD workshops and home-visits and disseminating accurate online information about CKD. Strategies should also focus on increasing patient engagement and optimising family support by involving family members in patients' care. Furthermore, clear dietary recommendations and patient-specific advice are needed to empower patients to manage their own condition.

Trace Proteinuria and the Incidence of Overt Proteinuria After Five Years: Results of the Kanagawa Investigation of the Total Checkup Data From the National Database-5 (KITCHEN-5)

Background

Trace proteinuria (TrP), which is usually defined as ± by dipstick urinalysis, is considered as normal and of limited clinical significance. However, the relationship between TrP and overt proteinuria (OP) (≥ +1) in the future is unknown. Therefore, we investigated the association between TrP and future incidence of OP in a community-based cohort study.

Methods

TrP detected during the initial 2 years, which was classified into transient TrP (once/2 years) (T-TrP) and recurrent TrP (twice/2 years) (R-TrP); and the incidence of OP after 5 years were investigated in 292,257 general Japanese people aged 40 - 68 years who attended checkups. To determine TrP and OP, dipstick urinalysis was conducted with visual reading (VR) by medical staff or automated reading (AR) using a machine reader.

Results

Overall, T-TrP and R-TrP were observed in 24,782 (8.5%) and 3,767 (1.3%) subjects, respectively. Both types of TrP were prevalent in the detection with AR than VR. The prevalences of T-TrP and R-TrP showed J-shaped relationships against baseline body mass index (BMI), regardless of sex and BMI categories. The incident of OP after 5 years was larger (around 10%) in R-TrP than T-TrP (around 5%): approximately two times. Logistic regression analysis showed that T-TrP and R-TrP were significantly associated with OP, even after adjustment for relevant confounding factors including age, sex, and BMI (odds ratios (95% confidence intervals (CIs)): 2.77 (2.60 - 2.95) and 4.85 (4.34 - 5.43)), which were not largely altered when sub-analysis was conducted according to men and women, non-obesity and obesity, or AR and VR. In all analysis above, the odds ratios (95% CIs) of R-TrP for OP were higher than T-TrP.

Conclusions

Our findings suggest that TrP, particularly R-TrP, is substantially associated with the future incidence of OP, which may be independent of confounding factors and the methods detecting TrP.