Selective Partitioned Regression for Accurate Kidney Health Monitoring

The number of people diagnosed with advanced stages of kidney disease have been rising every year. Early detection and constant monitoring are the only minimally invasive means to prevent severe kidney damage or kidney failure. We propose a cost-effective machine learning-based testing system that can facilitate inexpensive yet accurate kidney health checks. Our proposed framework, which was developed into an iPhone application, uses a camera-based bio-sensor and state-of-the-art classical machine learning and deep learning techniques for predicting the concentration of creatinine in the sample, based on colorimetric change in the test strip. The predicted creatinine concentration is then used to classify the severity of the kidney disease as healthy, intermediate, or critical. In this article, we focus on the effectiveness of machine learning models to translate the colorimetric reaction to kidney health prediction. In this setting, we thoroughly evaluated the effectiveness of our novel proposed models against state-of-the-art classical machine learning and deep learning approaches. Additionally, we executed a number of ablation studies to measure the performance of our model when trained using different meta-parameter choices. Our evaluation results indicate that our selective partitioned regression (SPR) model, using histogram of colors-based features and a histogram gradient boosted trees underlying estimator, exhibits much better overall prediction performance compared to state-of-the-art methods. Our initial study indicates that SPR can be an effective tool for detecting the severity of kidney disease using inexpensive lateral flow assay test strips and a smart phone-based application. Additional work is needed to verify the performance of the model in various settings.

Kidney function decline mediates the adverse effects of per- and poly-fluoroalkyl substances (PFAS) on uric acid levels and hyperuricemia risk

Previous studies indicated per- and poly-fluoroalkyl substances (PFAS) were related to uric acid and hyperuricemia risk, but evidence for the exposure-response (E-R) curves and combined effect of PFAS mixture is limited. Moreover, the potential mediation effect of kidney function was not assessed. Hence, we conducted a national cross-sectional study involving 13,979 US adults in NHANES 2003-2018 to examine the associations of serum PFAS with uric acid and hyperuricemia risk, and the mediation effects of kidney function. Generalized linear models and E-R curves showed positive associations of individual PFAS with uric acid and hyperuricemia risk, and nearly linear E-R curves indicated no safe threshold for PFAS. Weighted quantile sum regression found positive associations of PFAS mixture with uric acid and hyperuricemia risk, and PFOA was the dominant contributor to the adverse effect of PFAS on uric acid and hyperuricemia risk. Causal mediation analysis indicated significant mediation effects of kidney function decline in the associations of PFAS with uric acid and hyperuricemia risk, with the mediated proportion ranging from 19 % to 57 %. Our findings suggested that PFAS, especially PFOA, may cause increased uric acid and hyperuricemia risk increase even at low levels, and kidney function decline plays a crucial mediation effect.

8-OHdG mediates the association of co-exposure to fifty-five typical endocrine-disrupting chemicals with renal function: a cross-section investigation in Southern Chinese adults

Individual typical endocrine-disrupting chemicals (EDCs), including organophosphate triesters (OPEs), parabens, triclosan (TCS), bisphenols, benzophenones (BPs), phthalates (PAEs), and synthetic phenolic antioxidants (SPAs), are associated with renal dysfunction. However, the combined effects and underlying mechanisms of mixed EDC exposure on renal function remain unclear. Two hundred ninety-nine adult participants were enrolled in the cross-sectional survey conducted in Guangzhou, China. Urinary levels of 7 OPEs, 6 parabens, TCS, 14 bisphenols, 8 BPs, 15 PAEs, 4 SPAs, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were determined, and estimated glomerular filtration rate (eGFR) was served as the outcome index. We found elevated levels of diphenyl phosphate (DPP), bisphenol A (BPA), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-butyl phthalate (MBP) showed dose-responsive associations with eGFR decline, However, nonlinear associations were observed for bis(2-butoxyethyl) hydrogen phosphate (BBOEP), TCS, 4-hydroxybenzophenone (HBP), mono-n-pentyl phthalate (MnPP), and mono-benzyl phthalate (MBzP). The quantile-based g-computation model demonstrated that a quartile increase in the EDC mixture corresponded to a 0.383-SD decrease (95% CI - 0.658 ~  - 0.108, P = 0.007) in eGFR. Notably, BPA was identified as the primary contributor to this effect. Moreover, 8-OHdG mediated the eGFR decline associated with EDC mixtures with a mediation proportion of 25.49%. A sex-modified effect was also observed (P = 0.004), indicating that exposure to the mixture of EDC was linked to more pronounced renal dysfunction in females. Our novel findings suggest that exposure to a typical mixture of EDCs is associated with renal dysfunction in the general adult population of Southern China. Furthermore, 8-OHdG may play a role in the pathogenesis of EDC mixture-related renal dysfunction.

Safety and efficacy of nivolumab therapy in patients with metastatic renal cell carcinoma and impaired kidney function

INTRODUCTION

Patients with renal insufficiency, usually defined as those with creatinine clearance < 40 mL/min, were excluded from pivotal clinical trials, especially in studies involving nivolumab therapy in patients with renal cell carcinoma (RCC). The aim of the study is to evaluate the efficacy and safety of nivolumab in patients with metastatic RCC (mRCC) stratified according to creatinine clearance.

MATERIAL AND METHODS

Data from mRCC patients treated with nivolumab were retrospectively analyzed. Patients were classified into two categories according to their estimated glomerular filtration rate (eGFR); the first category (C1) included patients with eGFR < 40 mL/min/1.73 m2 and the second category (C2) included those with eGFR ≥ 40 mL/min/1.73 m2.

RESULTS

Of the 95 patients enrolled, 1. group included 26 patients (27.4%) and 2. group included 69 patients (72.6%). None of the pts in category 1 were on hemodialysis. Overall incidence of adverse events was not statistically different between the two groups (P = .469). The overall response rate ORR was 50% in the first group and 42.0% in the second group (P = .486). Median overall survival (OS) was longer with 23.3 months in the 2. group versus 11 months in the 1. group (P = .415).

CONCLUSION

Renal insufficiency is a common problem in patients with advanced renal cancer since they often undergo nephrectomy and their renal function may also worsen while receiving tyrosine kinase inhibitor therapy. We found that there is no significant difference in the safety and efficacy of nivolumab treatment between two groups. Nivolumab appears to be a safe and effective agent in patients with renal impairment.

New race-free creatinine- and cystatin C-based equations for the estimation of glomerular filtration rate and association with cardiovascular mortality in the AtheroGene study

Renal function is associated with cardiovascular outcomes and mortality. Among equations used to eGFR, CKD-EPI equations show more accurate association with cardiovascular risk and mortality than MDRD. Recently, new CKD-EPI equations were proposed which do not include race and would be considered sufficiently accurate to estimate eGFR in clinical practice. It is unknown if these new race-free equations are comparably well associated with cardiovascular outcomes in high-risk individuals. The analysis was performed in the AtheroGene Study cohort including patients at high cardiovascular risk. eGFR was determined using the established as well as the recently developed formulas which are calculated without the otherwise existing coefficient for black race. The outcome was cardiovascular death. Analyses included Cox-proportional hazard regression and area-under-the-curve calculation. The analysis included 2089 patients followed up for a median of 3.8 years with a maximum of 6.9 years, corresponding to an overall period of 7701 patient-years. Cardiovascular death occurred in 93 (4.45%), corresponding to an annualized rate of 1.2/100 person-years. In all Cox regression analyses, the estimated adjusted GFR was an independent predictor of cardiovascular death. The equations which included cystatin C showed higher C-index compared to those which did not include cystatin C (0.75-0.76 vs. 0.71, respectively). The equations for the estimation of eGFR which include cystatin C are better associated with cardiovascular death compared to the race-free equations which include only creatinine. This finding adds on the related literature which supports the elimination of race in GFR-estimating equations, and promotion of the use of cystatin C.

Evaluation of eGFR methods in a sub-Saharan African community-based pediatric population

BACKGROUND

Accurate assessment of the estimated glomerular filtration rate (eGFR) plays a pivotal role in the early detection, management, and optimal medication dosing for chronic kidney disease (CKD). However, validation of eGFR, utilizing cystatin C-based equations, is limited in African children and adolescents with CKD. We evaluate the agreement of eGFR equations incorporating both cystatin C and creatinine in this specific population.

METHODS

This community-based study assessed CKD in children (2-15 years) using cystatin C and serum creatinine. eGFR agreement with the reference was evaluated with Bland-Altman plots, ROC curves, and Lin's CCC, using the Under-25 serum creatinine-cystatin C equation as the reference standard. Pairwise ROC comparisons assess the statistical differences in estimation equation agreement.

RESULTS

Among 666 children (mean age, 7.8 ± 3.8 years; 48.6% male), CKD prevalence was 11.6% (95% CI, 9.2-14.2%). Notably, the Chehade equation, using combined biomarkers, aligned best with the reference, displaying the lowest mean deviation (- 0.59; 95% CI, - 1.19 to 0.01), superior agreement (P10, 91.0%; P30, 96.70%), and highest discriminatory power (0.989). In contrast, CKD-EPI 2012 cystatin C had the highest mean deviation (- 35.90) and lowest discriminatory power (0.79). Equations combining creatinine and cystatin C (Schwartz, Chehade, Full Age Spectrum) demonstrated strong positive Lin's CCC with CKiD U25 creatinine-cystatin C, while Bouvet showed a notably weak correlation (Lin's CCC, 0.22).

CONCLUSION

In African children with CKD, the Chehade, CKiD Under 25 creatinine-based equations, and the Full Age Spectrum equations show promise for CKD diagnosis. However, a measured GFR is essential to identifying the most accurate eGFR equation in this population.

Association between branched-chain amino acids and renal function in the ELSA-Brasil study

BACKGROUND & AIMS

Epidemiologic studies show high circulating Branched-chain amino acids (BCAA) are associated with excess body weight, impaired fasting glucose, insulin resistance, high blood pressure, and dyslipidemia. There is scarce data on the association between renal function and circulating levels of BCAA. Therefore, we aim to study this association in a sample of the Brazilian Longitudinal Study of Adults (ELSA-Brasil) METHODS: We analyzed participants who had at the baseline BCAA: valine, isoleucine, and leucine measured through nuclear magnetic resonance. The outcomes evaluated were estimated glomerular function (eGFR - CKD-EPI without race) and 12h-albumin-creatinine ratio (ACR). In addition, we built unadjusted and adjusted multivariable linear regression models to investigate the association between the BCAA (total and individual) and eGFR and ACR.

RESULTS

We studied 4912 participants (age 51.7(±9.0) years, 53.4% women, 59.5% White (59.5%), 32.7% hypertension, and 18.2% diabetes). The mean BCAA level was 429.15 ± 87.15. The mean eGFR was 84.95 ± 15 ml/min/1.73 m2, and the median ACR was 6.5 (1.8-4920) mg/g. Descriptive analyses comparing eGFR stratified <60 ml/min/1.73 m2 and ACR≥30 mg/g demonstrate that BCAA levels are higher in patients with eGFR<60 and ACR ≥30. Regarding eGFR, an inverse association was detected with BCAA levels when adjusted for demographic variables, and it is not maintained after adjustments for other confounders. Also, a positive association was found for ACR≥30 mg/g, and BCAA levels, and this association is not confirmed after adjustments.

CONCLUSIONS

BCAA levels were inversely associated with eGFR and positively associated with ACR. Further studies are necessary to allow the comprehension of those associations.

Diet quality in relation to kidney function and its potential interaction with genetic risk of kidney disease among Dutch post-myocardial infarction patients

PURPOSE

We examined the relation between diet quality, its components and kidney function decline in post-myocardial infarction (MI) patients, and we explored differences by genetic risk of chronic kidney disease (CKD).

METHODS

We analysed 2169 patients from the Alpha Omega Cohort (aged 60-80 years, 81% male). Dietary intake was assessed at baseline (2002-2006) using a validated food-frequency questionnaire and diet quality was defined using the Dutch Healthy Diet Cardiovascular Disease (DHD-CVD) index. We calculated 40-months change in estimated glomerular filtration rate (eGFR, mL/min per 1.73m2). We constructed a weighted genetic risk score (GRS) for CKD using 88 single nucleotide polymorphisms previously linked to CKD. Betas with 95%-confidence intervals (CIs) were obtained using multivariable linear regression models for the association between DHD-CVD index and its components and eGFR change, by GRS.

RESULTS

The average DHD-CVD index was 79 (SD 15) points and annual eGFR decline was 1.71 (SD 3.86) mL/min per 1.73 m2. The DHD-CVD index was not associated with annual eGFR change (per 1-SD increment in adherence score: -0.09 [95% CI -0.26,0.08]). Results for adherence to guidelines for red meat showed less annual eGFR decline (per 1-SD: 0.21 [0.04,0.38]), whereas more annual eGFR decline was found for legumes and dairy (per 1-SD: -0.20legumes [-0.37,-0.04] and - 0.18dairy [-0.34,-0.01]). Generally similar results were obtained in strata of GRS.

CONCLUSION

The DHD-CVD index for overall adherence to Dutch dietary guidelines for CVD patients was not associated with kidney function decline after MI, irrespective of genetic CKD risk. The preferred dietary pattern for CKD prevention in CVD patients warrants further research.

Exposures to drinking water disinfection byproducts and kidney function in Chinese women

BACKGROUND

Disinfection byproducts (DBPs), the ubiquitous contaminants in drinking water, have been shown to impair renal function in experimental studies. However, epidemiological evidence is sparse.

OBJECTIVE

To investigate exposures to DBPs in associations with renal function among women.

METHODS

A total of 920 women from December 2018 to January 2020 were abstracted from the Tongji Reproductive and Environmental (TREE) Study, an ongoing cohort study in Wuhan, China. Urine samples were gathered at baseline recruitment and analyzed for dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) as biomarkers of DBP exposures. Serum uric acid (UA), creatinine, and estimated glomerular filtration rate (eGFR) were measured as indicators of renal function. Multivariate linear regression and restricted cubic spline (RCS) models were conducted to assess urinary DCAA and TCAA concentrations in associations with renal function indicators. Stratified analyses by age and body mass index (BMI) were also performed.

RESULTS

We found null evidence of urinary TCAA in associations with renal function indicators. However, elevated urinary DCAA tertiles were related to decreased eGFR (β = -1.78%, 95% CI: 3.21%, -0.36%, comparing the upper vs. lower tertile; P for trend = 0.01). This inverse association still existed when urinary DCAA concentration was treated as a continuous variable, and the dose-response relationship was linear based on the RCS model (P for overall association = 0.002 and P for non-linear associations = 0.44). In the stratified analyses, we found an association of urinary DCAA concentration with decreased UA level among women <30 years but an association with increased UA level among women ≥30 years (P for interaction = 0.04).

CONCLUSION

Urinary DCAA but not TCAA was associated with impaired renal function among women undergoing assisted reproductive technology.

Exploring Renal Function Assessment: Creatinine, Cystatin C, and Estimated Glomerular Filtration Rate Focused on the European Kidney Function Consortium Equation

Serum creatinine and serum cystatin C are the most widely used renal biomarkers for calculating the estimated glomerular filtration rate (eGFR), which is used to estimate the severity of kidney damage. In this review, we present the basic characteristics of these biomarkers, their advantages and disadvantages, some basic history, and current laboratory measurement practices with state-of-the-art methodology. Their clinical utility is described in terms of normal reference intervals, graphically presented with age-dependent reference intervals, and their use in eGFR equations.

Efficacy of dotinurad in patients with severe renal dysfunction

BACKGROUND

Although hyperuricemia is associated with the progression of chronic kidney disease (CKD), a reduction in CKD progression by uric acid (UA)-lowering therapy has been controversial. Recently, dotinurad, a uricosuric drug with selective urate reabsorption inhibitory properties, has been developed. However, its efficacy in lowering serum UA levels and its effects on renal function in patients with severe renal dysfunction are unclear. Thus, this study aimed to determine the effects of dotinurad on renal function in patients with severe renal dysfunction.

METHODS

Data from 53 outpatients with hyperuricemia who newly received dotinurad between December 2020 and October 2022 were retrospectively analyzed. The mean baseline estimated glomerular filtration rate (eGFR) was 38.7 ± 17.0 mL/min/1.73 m2. The patients were divided into three groups based on their baseline eGFR: eGFR < 30 (n = 17), 30 ≤ eGFR < 45 (n = 17), and eGFR ≥ 45 (n = 19).

RESULTS

The mean follow-up period was 9.8 ± 4.5 (range, 3-21) months. Serum UA levels significantly decreased in all groups. Although eGFR did not significantly change in patients with 30 ≤ eGFR < 45 and eGFR ≥ 45 (P = 0.918 and P = 0.535, respectively), it improved significantly in patients with eGFR < 30 (P = 0.032). The proportion of patients with improved eGFR was significantly higher in patients with eGFR < 30 (P = 0.038) than in patients with 30 ≤ eGFR < 45 and eGFR ≥ 45. In the multivariate logistic regression analysis, baseline eGFR < 30 and achieving a serum UA level of ≤ 6.0 mg/dL were significantly associated with improved eGFR (P = 0.033 and P = 0.015, respectively).

CONCLUSIONS

Dotinurad may have UA-lowering effects and the potential to improve kidney function in patients with severe renal dysfunction.

The association between the estimated glomerular filtration rate and cognitive impairment: the Suita Study

This cross-sectional study investigated the association between the estimated glomerular filtration rate (eGFR), a measure of chronic kidney disease (CKD), and cognitive impairment. We used data from 6215 Japanese individuals registered in the Suita Study. Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score of ≤ 26. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of cognitive impairment for eGFR 45-59.9 and < 45 mL/min/1.73 m2 (mild and moderate-to-severe eGFR reductions) compared to eGFR ≥ 60 mL/min/1.73 m2 (normal eGFR). The results showed that both mild and moderate-to-severe eGFR reductions were associated with cognitive impairment: ORs (95% CIs) = 1.49 (1.22-1.83) and 2.35 (1.69-3.26), respectively (p-trend < 0.001). Each increment of eGFR by 10 mL/min/1.73m2 was associated with 4.8% lower odds of cognitive impairment. In conclusion, eGFR reduction was associated with cognitive impairment. Managing CKD is essential for preventing cognitive impairment.

Renal dysfunction in routine proton-pump inhibitor use may be linked to comorbidities: A real-world observational study

INTRODUCTION

The use of proton-pump inhibitors (PPI) is linked with infrequent but serious adverse events, including acute kidney injury, chronic kidney disease (CKD) and progression of CKD. Data on renal safety in routine use of PPI are more relevant to clinical practice. We studied whether such use of PPI is associated with renal dysfunction.

METHODS

Patients taking PPI for at least six weeks had serum creatinine tested pre (n = 200) and post (n = 180) recruitment. These patients were then advised to follow-up: those taking PPI for at least 90 days in the next six months (n = 77) and at least another 90 days in the following six months (n = 50), had serum creatinine tested at such follow-up. Renal dysfunction was defined as any increase in serum creatinine level above baseline.

RESULTS

The 200 patients recruited had mean age 39.6 (SD 9.2) years. Ninety-eight (49%) patients had a history of previous PPI use (median six months; interquartile range [IQR] 3-24). Only 20 (11.1%) patients at six weeks, 11 (14.3%) at six months and six (12%) at one year had increase in creatinine level; a majority of them had less than 0.3 mg/dL increase. Ten of these 20 (six weeks), five of 11 (six months) and five of six (one year) had other risk factors for renal dysfunction. No patient developed CKD during the study period.

CONCLUSIONS

Mild and non-progressive increase in serum creatinine occurred in 10% to 15% of patients on routine PPI use. A majority of them had other risk factors. Small sample size and short follow-up duration are a few limitations of this study.

Assessing bias in GFR estimating equations: improper GFR stratification can yield misleading results

BACKGROUND

Assessing bias (estimated - measured) is key to evaluating glomerular filtration rate (GFR). Stratification by subgroups can indicate where equations perform differently. However, there is a fallacy in the assessment of two instruments (e.g., eGFR and mGFR) when stratifying on the level of only one of those instruments. Here, we present statistical aspects of the problem and a solution for GFR stratification along with an empirical investigation using data from the CKiD study.

METHODS

Compared and contrasted biases (eGFR relative to mGFR) with 95% confidence intervals within strata of mGFR only, eGFR only, and the average of mGFR and eGFR using data from the Chronic Kidney Disease in Children (CKiD) study.

RESULTS

A total of 304 participants contributed 843 GFR studies with a mean mGFR of 48.46 (SD = 22.72) and mean eGFR of 48.67 (SD = 22.32) and correlation of 0.904. Despite strong agreement, eGFR significantly overestimated mGFR when mGFR < 30 (+ 6.2%; 95%CI + 2.9%, + 9.7%) and significantly underestimated when mGFR > 90 (-12.2%; 95%CI - 17.3%, - 7.0%). Significant biases in opposite direction were present when stratifying by eGFR only. In contrast, when stratifying by the average of eGFR and mGFR, biases were not significant (+ 1.3% and - 1.0%, respectively) congruent with strong agreement.

CONCLUSIONS

Stratifying by either mGFR or eGFR only to assess eGFR biases is ubiquitous but can lead to inappropriate inference due to intrinsic statistical issues that we characterize and empirically illustrate using data from the CKiD study. Using the average of eGFR and mGFR is recommended for valid inferences in evaluations of eGFR biases.

Development and Validation of a Multivariable Nomogram Predictive of Post-Nephroureterectomy Renal Function

BACKGROUND AND OBJECTIVE

The timing of perioperative nephrotoxic chemotherapy for upper tract urothelial carcinoma (UTUC) remains controversial and strongly depends on predicted platinum eligibility after radical nephroureterectomy (RNU). The study objective was to develop and validate a multivariable nomogram to predict estimated glomerular filtration rate (eGFR) following RNU.

METHODS

This was a multi-institutional retrospective study of patients with UTUC treated with RNU from 2000 to 2020 at seven high-volume referral centers. Use of adjuvant chemotherapy was risk-stratified. Patients were retrospectively randomly allocated 2:1 to discovery and validation cohorts. Discovery data were used to identify independent factors associated with GFR at 1-3 mo after RNU on linear regression, and backward selection was applied for model construction. Accuracy was defined as the percentage of predicted eGFR results within 30% of the corresponding observed eGFR.

KEY FINDINGS AND LIMITATIONS

We included 1100 patients, of whom 733 were in the discovery and 367 were in the validation cohort. Multivariable predictors of postoperative eGFR decline included advanced age (odds ratio [OR] -0.18, 95% confidence interval [CI] -0.28 to -0.08), diabetes (OR -2.38, 95% CI -4.64 to -0.11), and hypertension (OR -2.24, 95% CI -4.16 to -0.32). Factors associated with favorable postoperative eGFR included larger tumor size (OR 10.57, 95% CI 7.4-13.74 for tumors >5 cm vs ≤2 cm) and preoperative eGFR (OR 0.44, 95% CI 0.39-0.49). A composite nomogram predicted postoperative eGFR with good accuracy in both the discovery (80.5%) and validation (78.6%) cohorts. Limitations include exclusion of patients who received neoadjuvant chemotherapy.

CONCLUSIONS

A nomogram that incorporates ubiquitous preoperative clinical variables can predict post-RNU eGFR and was validated with an independent cohort.

PATIENT SUMMARY

We developed a tool that uses patient data to predict eligibility for chemotherapy after surgery to remove the kidney and ureter in patients with cancer in the upper urinary tract.

Coffee consumption affects kidney function based on GCKR polymorphism in a Korean population

Kidney function can be preserved through pharmacological interventions and nonpharmacological strategies, such as lifestyle and dietary adjustments. Among these, coffee has been linked to protective effects on kidney function. However, few studies have investigated the effect of coffee consumption on kidney function according to specific genes. We hypothesized that the impact of coffee consumption on kidney function might vary depending on GCKR polymorphism. GCKR rs1260326 polymorphism was examined using the Korean genome and epidemiology data from 656 chronic kidney disease (CKD) cases and 38,540 individuals without CKD (non-CKD). GCKR polymorphism has been previously associated with both coffee consumption and kidney function in Europeans. We replicated the associations between GCKR rs1260326 and coffee consumption and kidney function in Korean individuals. We also explored the effect of coffee consumption on kidney function by multivariate logistic regression analysis. Individuals with the rs1260326 (TC/CC) genotype did not experience significant changes in CKD risk based on their coffee consumption habits. In contrast, individuals with the TT genotype exhibited a significantly lower risk of CKD based on coffee consumption. Interestingly, in the non-CKD group, a beneficial effect on estimated glomerular filtration rate was observed in individuals with the T allele as coffee consumption increased. Our findings supported the hypothesis and revealed that the impact of coffee consumption habits on kidney function may vary based on the GCKR rs1260326 genotype of Korean individuals.

Which dose of apixaban is suitable for Asian patients with atrial fibrillation who have a serum creatinine < 1.5 mg/dL but an estimated glomerular filtration rate < 50 mL/min?

Introduction

Reduced-dose (Low-dose [LD]) apixaban is recommended in patients with atrial fibrillation (AF) who fulfill 2 of 3 criteria: age ≥ 80 years, body weight ≤ 60 kg, and a serum creatinine (sCr) ≥ 1.5 mg/dl. However, the suitable (appropriate) dose for Asian patients who have a sCr < 1.5 mg/dl but an estimated glomerular filtration rate (eGFR) < 50 mL/min is unknown.

Methods

This is a retrospective study using the Chang Gung Memorial hospital medical database in Taiwan. A total of 13,508 AF patients receiving oral anticoagulants (OACs) from 2012 to 2018 were reviewed and 1595 patients with a sCr < 1.5 mg/dL and an eGFR < 50 mL/min who met 1 criterion of dose reduction of apixaban other than sCr (that is, age ≥ 80 years or body weight < 60 kg) were identified. Clinical outcomes were compared between LD and SD apixaban versus warfarin.

Results

Their OACs use was as follows: 343 receiving apixaban (128 patients on standard dose [SD] and 215 on LD), 174 receiving warfarin, and 1078 on other NOACs. Patients with an eGFR < 50 mL/min had higher risk of mortality (adjusted hazard ratio [aHR], 1.264; 95 % confidence interval [CI], 1.086-1.472) and composite endpoint of 'ischemic stroke/systemic embolism (IS/SE) or major bleeding or mortality (aHR, 1.202; 95 % CI, 1.056-1.370) compared to those with an eGFR ≥ 50 mL/min whereas the risk of IS/SE and major bleeding were similar. LD apixaban was associated with lower risk of composite endpoint of IS/SE or major bleeding (aHR, 0.567; 95 % CI, 0.331 - 0.972), mortality (aHR, 0.336; 95 % CI, 0.138 - 0.815), and 'IS/SE or major bleeding or mortality (aHR, 0.551; 95 % CI, 0343 - 0.886) compared to warfarin while the risk was comparable between SD apixaban and warfarin (aHR, 0.745; 95 % CI, 0.402 - 1.378; aHR, 0.407; 95 % CI, 0.145 - 1.143; aHR, 0.619; 95 % CI, 0.354 - 1.084, respectively).

Conclusion

In patients with sCr < 1.5 mg/dL and eGFR < 50 mL/min, SD and LD apixaban were comparable in the prevention of IS/SE, but LD apixaban was superior in reducing the composite endpoint of 'IS/SE or major bleeding or mortality'. Therefore, LD apixaban might be a preferred dose for this population.

Estimated glomerular filtration rate among intensive care unit survivors: From the removal of race coefficient to cystatin C-based equations

PURPOSE

Black race coefficient used in serum creatinine (sCr)-based estimated glomerular filtration rate (eGFR) calculation may perpetuate racial disparities. Among intensive care unit (ICU) survivors, sCr overestimates kidney function due to sarcopenia. Cystatin C (cysC) is a race- and muscle mass-independent eGFR marker. We investigated the impact of removing the race coefficient from sCr-based eGFR and compared cysC- and sCr-based eGFR in ICU survivors.

MATERIALS AND METHODS

Among 30,920 patients from 2 institutions in the Bronx and Boston, eGFR was calculated at hospital discharge using sCr-based equations with and without race coefficient (eGFRsCr2009 and eGFRsCr2021). In a subset with available cysC between ICU admission and 1-year follow-up, sCr- and cysC-based estimates were compared.

RESULTS

eGFRsCr2021 was higher than eGFRsCr2009 by a median of 4 ml/min/1.73 m2 among non-Black patients and lower by a median of 8 ml/min/1.73 m2 among Black patients. Removing race coefficient reclassified 12.9% of non-Black subjects and 16.1% of Black subjects to better and worse eGFR category, respectively, and differentially impacted the prevalence of kidney dysfunction between the institutions due to differences in racial composition. Among 51 patients with available cysC (108 measurements), cysC-based estimates were lower than sCr-based estimates (median difference 9 to 16 ml/min/1.73 m2), resulting in reclassification to worse eGFR category in 34% to 53.5% of measurements.

CONCLUSIONS

Among ICU survivors, removal of race coefficient leads to lower eGFR in Black patients and may contribute to overestimation of kidney function in non-Black patients. While cysC is rarely used, estimates based on this marker are significantly lower than those based on sCr.

Decreased estimated glomerular filtration rate increase the risk of pancreatic cancer: A nationwide retrospective cohort study

BACKGROUND AND AIM

Decreased kidney function is a putative risk factor for various cancers. However, few studies have investigated the association between a decreased estimated glomerular filtration rate (eGFR) and incident pancreatic cancer. We aimed to investigate the risk of incident pancreatic cancer according to eGFR categories.

METHODS

In this retrospective cohort study, we included 359 721 adults who underwent health checkups in 2009 or 2010 by using the Korean National Health Insurance Database. The study population was categorized into four groups by eGFR (mL/min/1.73 m2 ) using the Chronic Kidney Disease Epidemiology Collaboration equation: group 1 (eGFR < 45), group 2 (eGFR ≥ 45 to < 60), group 3 (eGFR ≥ 60 to < 90), and group 4 (eGFR ≥ 90). Multivariate Cox proportional hazards models were used to determine the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of pancreatic cancer until 2019 by comparing the eGFR groups.

RESULTS

During the 3 493 589.05 person-years of follow-up, 1702 pancreatic cancer cases were identified. Compared with group 4 (eGFR ≥ 90), HRs and 95% CIs for the incidence of pancreatic cancer were 1.39 (1.24-1.56) for group 3 (eGFR ≥ 60 to < 90), 1.79 (1.47-2.16) for group 2 (eGFR ≥ 45 to < 60), and 2.05 (1.62-2.60) for group 1 (eGFR < 45) in the multivariate adjusted model.

CONCLUSIONS

Decreased eGFR was significantly associated with an increased risk of pancreatic cancer in Korean population. Further studies are needed to investigate the relationship between a decreased eGFR and the risk of pancreatic cancer in other ethnic groups.

Comparison and evaluation of the 2009 and 2021 chronic kidney disease-epidemiological collaboration equations among Jordanian patients with type 2 diabetes mellitus

AIMS

This study compared the 2009 versus 2021 chronic kidney disease (CKD) Epidemiological Collaboration (CKD-EPI) equations to calculate estimated glomerular filtration rate (eGFR) among Jordanian patients with T2DM to assess their agreement and impact on CKD staging.

METHODS

This cross-sectional study included 2382 adult Jordanian patients with T2DM. The 2009 and 2021 CKD-EPI equations were used to calculate eGFR. Patients were reclassified according to kidney disease-Improving Global Outcomes (KDIGO) categories. Agreement between the equations was assessed using Bland-Altman plots and Lin's concordance correlation.

RESULTS

The 2021 equation significantly increased eGFR by a median of 2.1 mL/min/1.73 m2 (interquartile range: 0.6-3.6 mL/min/1.73 m2). However, there was significant agreement between equations (Kappa: 0.99; 95% confidence interval: 0.95-1.00), independent of age, sex, and the presence of hypertension. In total, 202 patients (8.5%) were reclassified to higher KDIGO categories using the 2021 equation, with category G3 being most affected. The overall prevalence of patients in the high to highest risk categories decreased (28.0% vs. 26.5%).

CONCLUSIONS

Although there was significant agreement with the 2009 equation, the 2021 equation increased eGFR and resulted in the reclassification of a subset of subjects according to KDIGO criteria. The uncertain impact of reducing high-risk category patients raises concerns about potential delays in referral and intervention, while holding the potential to enhance high-risk patient categorization, thus alleviating healthcare burden.

Association of estimated glomerular filtration rate with prostate cancer risk in a cross-ethnic population: a Mendelian randomization study

OBJECTIVE

To investigate whether a causal relationship exists between the estimated glomerular filtration rate (EGFR) and the occurrence of prostate cancer in East Asian and European populations and to determine if genetic factors influence the association between the EGFR and prostate cancer risk.

METHODS

In this Mendelian randomization study, the existence of a causal relationship between the EGFR and prostate cancer occurrence was assessed using five analytical techniques, including Mendelian randomization-Egger regression (MR-Egger), calculation of the weighted median estimator (WME), the maximum likelihood ratio method, the linear median weighting method and the random-effects inverse-variance weighting (IVW) method.

RESULTS

In the IVW model, no causal relationship was observed between the EGFR and prostate cancer in either the East Asian or European populations.

CONCLUSIONS

After excluding confounding factors and reverse causal associations using two-sample Mendelian randomization, unbiased estimates were obtained, and there was no causal relationship between prostate cancer and the EGFR in the East Asian or European populations. Therefore, for patients with suspected prostate cancer, it is considered unnecessary to improve the detection of glomerular filtration rate, which will effectively reduce the economic burden of patients.

Heterogeneity by age and gender in the association of kidney function with mortality among patients with diabetes - analysis of diabetes registry in Singapore

BACKGROUND

We aimed to explore the three-way interaction among age, gender, and kidney function on the risk of all-cause mortality and cardiovascular mortality among patients with type 2 diabetes (T2D).

METHODS

In a retrospective cohort study, patients aged > 40 years with T2D with serum creatinine and urine albumin measured from 2013 to 2019 were included from a multi-institutional diabetes registry. The exposure was estimated glomerular filtration rate (eGFR), outcomes were all-cause mortality (primary outcome) and cardiovascular disease (CVD) mortality (secondary outcome). We applied multivariable cox proportional hazards regression analysis to compute the association between eGFR and mortality.

RESULTS

A total of 36,556 patients were followed for up to 6 years during which 2492 (6.82%) died from all causes, and 690 (1.9%) died from CVD. We observed a significant three-way interaction (p = 0.021) among age (younger, < 65; older, ≥65 years), gender and eGFR for the risk of all-cause mortality. Using age- and gender-specific eGFR of 90 ml/min/1.73m2 as the reference point, the adjusted hazard rate (HR) (95% CI) for all-cause mortality at eGFR of 40 ml/min/1.73m2 was 3.70 (2.29 to 5.99) in younger women and 1.86 (1.08 to 3.19) in younger men. The corresponding adjusted HRs in older women and older men were 2.38 (2.02 to 2.82) and 2.18 (1.85 to 2.57), respectively. Similar results were observed for CVD deaths, although the three-way interaction was not statistically significant. Sensitivity analysis yielded similar results.

CONCLUSIONS

In this T2D population, younger women with reduced kidney function might be more susceptible to higher risks of all-cause mortality and CVD mortality than younger men.

The causal relationship between COVID-19 and estimated glomerular filtration rate: a bidirectional Mendelian randomization study

BACKGROUND

Previous Mendelian studies identified a causal relationship between renal function, as assessed by estimated glomerular filtration rate (eGFR), and severe infection with coronavirus disease 2019 (COVID-19). However, much is still unknown because of the limited number of associated single nucleotide polymorphisms (SNPs) of COVID-19 and the lack of cystatin C testing. Therefore, in the present study, we aimed to determine the genetic mechanisms responsible for the association between eGFR and COVID-19 in a European population.

METHODS

We performed bidirectional Mendelian randomization (MR) analysis on large-scale genome-wide association study (GWAS) data; log-eGFR was calculated from the serum levels of creatinine or cystatin C by applying the Chronic Kidney Disease Genetics (CKDGen) Meta-analysis Dataset combined with the UK Biobank (N = 1,004,040) and on COVID-19 phenotypes (122,616 COVID-19 cases and 2,475,240 controls) from COVID19-hg GWAS meta-analyses round 7. The inverse-variance weighted method was used as the main method for estimation.

RESULTS

Analyses showed that the genetically instrumented reduced log-eGFR, as calculated from the serum levels of creatinine, was associated with a significantly higher risk of severe COVID-19 (odds ratio [OR]: 2.73, 95% confidence interval [CI]: 1.38-5.41, P < 0.05) and significantly related to COVID-19 hospitalization (OR: 2.36, 95% CI: 1.39-4.00, P < 0.05) or infection (OR: 1.24, 95% CI: 1.01-1.53, P < 0.05). The significance of these associations remained when using log-eGFR based on the serum levels of cystatin C as genetically instrumented. However, genetically instrumented COVID-19, regardless of phenotype, was not related to log-eGFR, as calculated by either the serum levels of creatinine or cystatin C.

CONCLUSIONS

Our findings suggest that genetical predisposition to reduced kidney function may represent a risk factor for COVID-19. However, a consistent and significant effect of COVID-19 on kidney function was not identified in this study.

Recent ambient temperature and fine particulate matter (PM2.5) exposure is associated with urinary kidney injury biomarkers in children

BACKGROUND

Limited research has examined associations between exposure to ambient temperature, air pollution, and kidney function or injury during the preadolescent period. We examined associations between exposure to ambient temperature and particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) with preadolescent estimated glomerular filtration rate (eGFR) and urinary kidney injury biomarkers.

METHODS

Participants included 437 children without cardiovascular or kidney disease enrolled in the Programming Research in Obesity, Growth, Environment and Social Stressors birth cohort study in Mexico City. eGFR and urinary kidney injury biomarkers were assessed at 8-12 years. Validated satellite-based spatio-temporal models were used to estimate mean daily temperature and PM2.5 levels at each participant's residence 7- and 30-days prior to the date of visit. Linear regression and distributed lag nonlinear models (DLNM) were used to examine associations between daily mean temperature and PM2.5 exposure and kidney outcomes, adjusted for covariates.

RESULTS

In single linear regressions, higher seven-day average PM2.5 was associated with higher urinary alpha-1-microglobulin and eGFR. In DLNM analyses, higher temperature exposure in the seven days prior to date of visit was associated with a decrease in urinary cystatin C of -0.56 ng/mL (95 % confidence interval (CI): -1.08, -0.04) and in osteopontin of -0.08 ng/mL (95 % CI: -0.15, -0.001). PM2.5 exposure over the seven days prior to date of visit was associated with an increase in eGFR of 1.77 mL/min/1.73m2 (95 % CI: 0.55, 2.99) and urinary cystatin C of 0.19 ng/mL (95 % CI: 0.03, 0.35).

CONCLUSIONS

Recent exposure to ambient temperature and PM2.5 were associated with increased and decreased urinary kidney injury biomarkers that may reflect subclinical glomerular or tubular injury in children. Further research is required to assess environmental exposures and worsening subclinical kidney injury across development.

Changes in estimated glomerular filtration rate in patients administered proton pump inhibitors: a single-center cohort study

Proton pump inhibitor (PPI) use may be associated with renal dysfunction. Renal dysfunction in PPI users requires evaluation of development and progression risks simultaneously, using estimated glomerular filtration rate (eGFR) slope, which indicates changes in eGFR per year. To the best of our knowledge, no studies have evaluated eGFR slope in PPI users. This study investigated the association between PPI use and renal dysfunction using eGFR slope. A single-center cohort study was conducted using the health records data at Hamamatsu University Hospital in Japan. Participants were defined as first users of acid-suppressing drugs (PPIs or Histamine H2 receptor antagonists (H2RAs)) from 2010 to 2021 and continuously prescribed for  ≥ 90 days. The H2RA group was used for the propensity-score matching (PSM) to the PPI group to minimize the effects of confounders. The eGFR slope was estimated using a linear mixed effects model. Participants were stratified by baseline eGFR and age, respectively, as subgroup analyses. A total of 4,649 acid-suppressing drug users met the inclusion criteria, including 950 taking H2RAs and 3,699 PPIs. After PSM, 911 patients were assigned to each group. The eGFR slopes of the PPI and H2RA users were -4.75 (95% CI: -6.29, -3.20) and -3.40 (-4.38, -2.42), respectively. The difference between the groups was not significant. Significant declines in eGFR were observed with PPIs with baseline eGFR ≥ 90 and age  < 65. PPI use for  ≥ 90 days may hasten eGFR decline compared to H2RA use, especially in patients with eGFR  ≥ 90 or age  < 65.

The impact of diabetes, anemia, and renal function in the relationship between osteoporosis and fasting blood glucose among Taiwanese women: a cross-sectional study

BACKGROUND

The aim of this study was to investigate the association between fasting blood glucose and osteoporosis in women with diabetes, anemia, and renal function.

METHODS

The medical records of women who underwent a general health examination at a regional hospital in southern Taiwan were retrospectively reviewed. Logistic regression analysis was performed to assess the association between osteoporosis and fasting blood glucose separately for the eight subgroups (diabetes or non-diabetes, anemia or non-anemia, normal or decreased renal function), adjusting for other clinical characteristics and laboratory findings.

RESULTS

A total of 11,872 women were included in the study. Among women with diabetes, anemia, and decreased renal function, an increment of 10 mg/dL in fasting blood glucose was associated with an increased risk of osteoporosis (adjusted odds ratio [aOR] = 1.57, p = 0.004). Among women without diabetes, fasting blood glucose was significantly associated with an increased risk of osteoporosis in those with anemia and normal renal function (OR = 1.14, p = 0.023) and those without anemia and normal renal function (OR = 1.04, p = 0.015), but these associations were not significant after adjusting for other covariates.

CONCLUSIONS

Higher fasting blood glucose levels in women with diabetes, anemia, and decreased renal function were associated with an increased risk of osteoporosis. Clinicians should be vigilant about glucose control in patients with diabetes to reduce the risk of fracture.

Is Kidney Function Associated with Age-Related Macular Degeneration?: Findings from the Asian Eye Epidemiology Consortium

PURPOSE

Chronic kidney disease (CKD) may elevate susceptibility to age-related macular degeneration (AMD) because of shared risk factors, pathogenic mechanisms, and genetic polymorphisms. Given the inconclusive findings in prior studies, we investigated this association using extensive datasets in the Asian Eye Epidemiology Consortium.

DESIGN

Cross-sectional study.

PARTICIPANTS

Fifty-one thousand two hundred fifty-three participants from 10 distinct population-based Asian studies.

METHODS

Age-related macular degeneration was defined using the Wisconsin Age-Related Maculopathy Grading System, the International Age-Related Maculopathy Epidemiological Study Group Classification, or the Beckman Clinical Classification. Chronic kidney disease was defined as estimated glomerular filtration rate (eGFR) of less than 60 ml/min per 1.73 m2. A pooled analysis using individual-level participant data was performed to examine the associations between CKD and eGFR with AMD (early and late), adjusting for age, sex, hypertension, diabetes, body mass index, smoking status, total cholesterol, and study groups.

MAIN OUTCOME MEASURES

Odds ratio (OR) of early and late AMD.

RESULTS

Among 51 253 participants (mean age, 54.1 ± 14.5 years), 5079 had CKD (9.9%). The prevalence of early AMD was 9.0%, and that of late AMD was 0.71%. After adjusting for confounders, individuals with CKD were associated with higher odds of late AMD (OR, 1.46; 95% confidence interval [CI], 1.11-1.93; P = 0.008). Similarly, poorer kidney function (per 10-unit eGFR decrease) was associated with late AMD (OR, 1.12; 95% CI, 1.05-1.19; P = 0.001). Nevertheless, CKD and eGFR were not associated significantly with early AMD (all P ≥ 0.149).

CONCLUSIONS

Pooled analysis from 10 distinct Asian population-based studies revealed that CKD and compromised kidney function are associated significantly with late AMD. This finding further underscores the importance of ocular examinations in patients with CKD.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Trajectories of kidney function and risk of mortality

BACKGROUND

We aimed to identify patterns within the rate of kidney function decline, determinants of these patterns and their association with all-cause mortality risk in the general population.

METHODS

Participants aged ≥ 45 years with at least one assessment of creatinine-based estimated glomerular filtration rate (eGFR) taken between 1997 and 2018 were selected from a population-based cohort study. Analyses were performed using several distinct latent class trajectory modelling methods. Cumulative incidences were calculated with 45 years of age as the starting point.

RESULTS

In 12 062 participants (85 922 eGFR assessments, mean age 67.0 years, 58.7% women, median follow-up 9.6 years), four trajectories of eGFR change with age were identified: slow eGFR decline [rate of change in mL/min/1.73 m2 per year (RC), -0.9; 95% CI, -0.9 to -0.9; reference group], intermediate eGFR decline (RC, -2.5; 95% CI, -2.7 to -2.5) and fast eGFR decline (RC, -4.3; 95% CI, -4.4 to -4.1), and an increase/stable eGFR (RC, 0.3; 95% CI, 0.3 to 0.4). Women were more likely to have an increase/stable eGFR [odds ratio (OR), 1.94; 95% CI, 1.53 to 2.46] whereas men were more likely to have a fast eGFR decline (OR, 1.86; 95% CI, 1.33 to 2.60). Participants with diabetes, cardiovascular disease (CVD) or hypertension were more likely to have an intermediate or fast eGFR decline. All-cause mortality risks (cumulative incidence at age of 70 years) were 32.3% (95% CI, 21.4 to 47.9, slow eGFR decline), 6.7% (95% CI, 3.5 to 12.4, intermediate eGFR decline), 68.8% (95% CI, 44.4 to 87.8, fast eGFR decline) and 9.5% (95% CI, 5.5 to 15.7, increase/stable eGFR).

CONCLUSION

Sex, hypertension, diabetes and CVD were identified as trajectory membership determinants. Having fast eGFR decline was associated with the highest risk of all-cause mortality, highlighting the need for extensive monitoring and prevention of kidney function decline in individuals at risk of having fast eGFR decline.

Kidney function and other associated factors of sarcopenia in community-dwelling older adults: The SCOPE study

AIM

Sarcopenia is associated with several factors and medical conditions among older adults, though previous research has shown limitations and inconsistencies, especially regarding chronic kidney disease (CKD). We investigated the clinical and laboratory variables associated with sarcopenia and severe sarcopenia in older adults, focusing on kidney function measures.

METHODS

Data from community-dwelling adults aged ≥75 years participating in the SCOPE multicenter prospective cohort study were assessed cross-sectionally. Comprehensive geriatric assessment was conducted; sociodemographic and lifestyle factors, clinical variables and comorbidities, anthropometric and bioelectrical impedance analysis, blood and urine laboratory variables were collected. EWGSOP2 revised criteria were used to define sarcopenia and its severity. Estimated glomerular filtration rate (eGFR) was calculated using creatinine and non-creatinine-based equations, and CKD stages were defined accordingly.

RESULTS

1420 participants were included, prevalence of sarcopenia was 10.6 %, and 6 % had severe sarcopenia. Multivariate logistic regression analysis showed that age [OR =1.14; 95 %CI (1.09-1.19)], body mass index (BMI) [0.83 (0.79-0.88)], disability performing instrumental activities of daily living (IADL) [2.61 (1.69-4.06)], Mini Mental State Examination (MMSE) score <24 [2.75 (1.62-4.67)], osteoporosis [2.39 (1.55-3.67)], and stage 4 CKD defined by CKD-EPIBTP-B2M, a non-creatinine-based eGFR equation [2.88 (1.11-7.49)], were independently associated with sarcopenia; as were specifically with severe sarcopenia, with more pronounced associations.

CONCLUSIONS

In community-dwelling older adults, sarcopenia is a relevant condition and is associated with severe CKD, older age, IADL, cognitive impairments, osteoporosis and low BMI. These factors should be assessed for proper identification and management of older patients with sarcopenia, and even more so with severe sarcopenia.

Association of fresh vegetable and salt-preserved vegetable consumptions with estimated glomerular filtration rate

OBJECTIVE

This study aimed to investigate the relationship between the consumption of fresh and salt-preserved vegetables and the estimated glomerular filtration rate (eGFR), which requires further research.

METHODS

For this purpose, the data of those subjects who participated in the 2011-2012 and 2014 surveys of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and had biomarker data were selected. Fresh and salt-preserved vegetable consumptions were assessed at each wave. eGFR was assessed using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on plasma creatinine. Furthermore, a linear mixed model was used to evaluate associations between fresh/salt-preserved vegetables and eGFR.

RESULTS

The results indicated that the median baseline and follow-up eGFRs were 72.47 mL/min/1.73 m² and 70.26 mL/min/1.73 m², respectively. After applying adjusted linear mixed model analysis to the data, the results revealed that compared to almost daily intake, occasional consumption of fresh vegetables was associated with a lower eGFR (β=-2.23, 95% CI: -4.23, -0.23). Moreover, rare or no consumption of salt-preserved vegetables was associated with a higher eGFR (β = 1.87, 95% CI: 0.12, 3.63) compared to individuals who consumed salt-preserved vegetables daily.

CONCLUSION

Fresh vegetable consumption was direct, whereas intake of salt-preserved vegetables was inversely associated with eGFR among the oldest subjects, supporting the potential benefits of diet-rich fresh vegetables for improving eGFR.

Relationship between bone marrow adipose tissue and kidney function in postmenopausal women

Introduction

Bone marrow adipose tissue (BMAT) is associated with aging, osteoporosis, and chronic kidney disease (CKD). To date, the association between BMAT and kidney function in postmenopausal women has not been thoroughly investigated. The main purpose of this study was to determine whether a relationship exists between proton density fat fraction (PDFF) and kidney function in postmenopausal women.

Methods

We investigated the cross-sectional association between estimated glomerular filtration rate (eGFR) - calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation - and PDFF - measured at the lumbar spine and proximal femur using Water Fat Imaging (WFI) MRI - in 199 postmenopausal women from the ADIMOS cohort study. We also performed DXA scans and laboratory measurements of sclerostin and c-terminal Fibroblast Growth Factor 23 (cFGF23).

Results

Participants' mean age was 67.5 (standard deviation, SD 10.0) years. Their median eGFR was 85.0 (interquartile range, IQR 72.2-95.0) ml/min/1.73 cm2, and their mean lumbar spine PDFF was 57.9 % (SD 9.6). When classified by eGFR-based CKD stages, 41.7 % of the cohort had an eGFR ≥ 90 (n = 83), 47.2 % had an eGFR of 60-89.9 (n = 94), and 11.1 % had an eGFR of 30-59.9 (n = 22). Participants with eGFR ≥ 90 had a lower lumbar spine PDFF than those with eGFR 60-89.9 (mean 55.8 % (9.8) vs. 58.9 % (9.0), p = 0.031) and those with eGFR 30-59.9 (55.8 % (9.8) vs. 60.8 % (9.8), p = 0.043). However, the differences did not remain significant after adjusting for predetermined confounders, including age, diabetes, Charlson comorbidity index, recent history of fragility fracture, appendicular lean mass, and lumbar spine BMD. The inclusion of sclerostin and/or cFGF23 as suspected mediators did not alter the findings. When proximal hip imaging-based PDFF was considered, no significant differences were found between the eGFR categories in the unadjusted and adjusted analyses.

Conclusion

No evidence of an association between kidney function and bone marrow adiposity was found either in the lumbar spine or proximal femur in a cohort of postmenopausal women.

Trajectories of eGFR after kidney transplantation according to trajectories of eGFR prior to kidney replacement therapies in children with chronic kidney disease

BACKGROUND

In children with chronic kidney disease (CKD), certain risk factors are associated with faster eGFR decline and earlier kidney failure. Whether these factors have lingering effects on post-transplant eGFR trajectory remains unclear. We characterized pre- and post-transplant eGFR trajectories in pediatric kidney transplant recipients by their pre-kidney replacement therapy (KRT) risk factors.

METHODS

We studied eGFR trajectories before KRT initiation and after transplantation among Chronic Kidney Disease in Children (CKiD) Study participants. We used mixed-effects models to compare pre-KRT versus post-transplant eGFR trajectories within individual participants by 7 pre-KRT risk factors: glomerular/non-glomerular etiology, race, preemptive transplant, proteinuria, albuminuria, and systolic/diastolic blood pressure (SBP/DBP).

RESULTS

We analyzed 1602 pre-KRT and 592 post-transplant eGFR measurements from 246 transplant recipients. Mean annual eGFR decline was decreased from 18.0% pre-KRT (95%CI, 16.1-19.8) to 5.0% post-transplant (95%CI, 3.3-6.7). All 7 pre-KRT risk factors showed strong associations with faster pre-KRT eGFR decline, but not with post-transplant eGFR decline; only albuminuria, high SBP, and high DBP reached statistical significance with notably attenuated associations. In our multivariable model of the pre-KRT risk factors, post-transplant eGFR decline was more rapid only when albuminuria and high SBP were both present.

CONCLUSIONS

eGFR decline substantially slows down after transplant even among children with rapidly progressing forms of CKD. Nonetheless, those who had albuminuria and high SBP before KRT might continue to show faster eGFR decline after transplant, specifically when both risk factors were present. This subgroup might benefit from intensive pre-transplant management for at least one of the two risk factors. A higher resolution version of the Graphical abstract is available as Supplementary information.

Long-Term Change in Renal Function After Intravitreal Anti-VEGF Treatment for Diabetic Macular Edema: A 2-Year Retrospective Cohort Study

INTRODUCTION

To investigate the longitudinal changes in renal function and associated factors after intravitreal anti-vascular endothelial growth factor (VEGF) administration in diabetic macular edema (DME).

METHODS

A total of 108 patients who had received intravitreal ranibizumab or aflibercept for DME and had follow-up visits for at least 2 years in one hospital were retrospectively enrolled. The estimated glomerular filtration rate (eGFR) at baseline and during the follow-up period and receipt of any renal replacement therapy were recorded. Linear regression and Cox regression models were used to evaluate factors associated with eGFR decline and renal replacement therapy.

RESULTS

After intravitreal anti-VEGF treatment, eGFR showed a mean decline of -10.4 ± 23.2% and -16.5 ± 26.4% at months 12 and 24, respectively. Patients in the eGFR > 120 mL/min and 15-30 mL/min groups had the greatest decline (-32.0 ± 20.6% and -37.4 ± 30.9%, respectively) while those in the 61-90 mL/min group had the smallest decline (-4.3 ± 19.7%) in eGFR after the 2-year treatment. One out of 52 patients (1.9%) receiving ranibizumab and five out of 56 patients (8.9%) receiving aflibercept started hemodialysis or peritoneal dialysis within the 2-year follow-up period (P = 0.21). Baseline eGFR correlated with renal replacement therapy after intravitreal anti-VEGF treatment (hazard ratio = 0.879 per increase of 1 in eGFR, P = 0.018).

CONCLUSIONS

In DME patients receiving intravitreal anti-VEGF treatment, a persistent decline in eGFR was observed during the 2-year treatment course. Patients with extremely high or low eGFR had greater eGFR decline, and those with poor baseline eGFR tended to require dialysis after intravitreal anti-VEGF treatment.

Long-term safety and efficacy of pegunigalsidase alfa: A multicenter 6-year study in adult patients with Fabry disease

PURPOSE

Fabry disease (FD) is a rare lysosomal storage disorder caused by pathogenic variants in the GLA gene encoding α-galactosidase (α-Gal)-A. We evaluated long-term safety/efficacy of pegunigalsidase alfa, a novel PEGylated α-Gal-A enzyme replacement therapy (ERT) now approved for FD.

METHODS

In a phase-1/2 dose-ranging study, 15 ERT-naive adults with FD completed 12 months of pegunigalsidase alfa and enrolled in this 60-month open-label extension of 1 mg/kg pegunigalsidase alfa infusions every 2 weeks.

RESULTS

Fifteen patients enrolled (8 males; 7 females); 10 completed ≥48 months (60 months total treatment), and 2 completed 60 months (72 months total treatment). During treatment, most treatment-emergent adverse events were mild/moderate in severity and all infusion-related reactions were mild/moderate in severity. Four patients were transiently positive for anti-pegunigalsidase alfa IgG. Patients showed continuous reduction in plasma lyso-Gb3 concentrations with mean (standard error) reduction of 76.1 [25.1] ng/mL from baseline to month 24. At 60 months, the estimated glomerular filtration rate slope was comparable to that observed in patients treated with other ERTs. Cardiac function assessments revealed stability; no cardiac fibrosis was observed.

CONCLUSION

In this first long-term assessment of pegunigalsidase alfa administration in patients with FD, we found favorable safety/efficacy. Our data suggest long-term continuous benefits of pegunigalsidase alfa treatment in adults with FD.

Association between 1-year changes in urinary albumin-to-creatinine ratio and kidney disease progression in Japanese individuals with diabetes: a historical cohort study

BACKGROUND

The National Kidney Foundation recently proposed a ≥ 30% decrease in urinary albumin-to-creatinine ratio (UACR) over 0.5-2 years as a surrogate endpoint for chronic kidney disease (CKD) progression in individuals with baseline UACR > 30 mg/g. This historical cohort study aimed to determine the applicability of a decrease in UACR, within as little as 1 year, as a surrogate endpoint for Japanese individuals with type 2 diabetes mellitus (T2D).

METHODS

A total of 5067 individuals with T2D were divided into three groups based on 1-year change in UACR: ≥ 30% decrease (UACR decreased group), < 30% decrease and < 30% increase (UACR unchanged group), or ≥ 30% increase (UACR increased group). The primary endpoint was a composite of a ≥ 30% decline in estimated glomerular filtration rate (eGFR) or the initiation of kidney replacement therapy, whichever occurred first.

RESULTS

At baseline, the proportions of individuals with normoalbuminuria, microalbuminuria, and eGFR ≥ 60 mL/min/1.73 m2 were 68.1%, 22.1%, and 75.5%, respectively. During a median follow-up of 6.8 years, 926 individuals (18.3%) reached the composite endpoint. Adjusted hazard ratios (vs. the UACR unchanged group) for the UACR decreased and increased groups were 0.758 (95% confidence interval [CI], 0.636-0.905; P = 0.002) and 1.304 (95% CI, 1.108-1.536; P = 0.001), respectively.

CONCLUSIONS

These findings support the use of 1-year changes in UACR as a surrogate endpoint for the progression of CKD and the implementation of a ≥ 30% decrease in UACR as a positive efficacy endpoint in Japanese individuals with T2D and early-stage kidney disease.

Meta-analysis of the effects of CPAP therapy on estimated glomerular filtration rate in patients with obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is highly prevalent in patients with chronic kidney disease and may lead to a loss of kidney function. However, it remains unclear whether or not continuous positive airway pressure (CPAP) treatment improves the estimated glomerular filtration rate (eGFR) in patients with OSA. This meta-analysis was designed to investigate the effect of CPAP therapy on eGFR in patients with OSA.

METHODS

We searched the electronic databases Web of Science, Cochrane Library, PubMed, and Embase through June 1, 2022. Information about patients, CPAP duration, gender distribution, pre- and post-CPAP treatment eGFR, and age of patients were collected for further analysis. We applied the standardized mean difference (SMD) with a 95%confidence interval (CI) to analyze the pooled effects. Both Stata 12.0 software and Review Manager 5.2 software were employed for all statistical analyses.

RESULTS

A sample of 13 studies with 519 patients was included in the meta-analysis. There was no significant change of eGFR levels before and after CPAP usage for patients with OSA (SMD =  - 0.05, 95%CI: - 0.30 to 0.19, Z = 0.43, p = 0.67). However, subgroup analysis revealed that the level of eGFR was obviously decreased after CPAP therapy in patients with OSA and CPAP use duration > 6 months (SMD =  - 0.30, 95% CI =  - 0.49 to - 0.12, z = 3.20, p = 0.001), and elderly patients (> 60 years) (SMD =  - 0.32, 95% CI =  - 0.52 to - 0.11, z = 3.02, p = 0.002).

CONCLUSIONS

Meta-analysis confirmed that OSA treatment with CPAP has no clinically significant effect on eGFR.

Population pharmacokinetics of rivaroxaban in Chinese deep vein thrombosis patients and the exposure simulation for dosing recommendation

This study aimed to develop a population pharmacokinetic (PPK) model for rivaroxaban and establish a model-based dosing guideline tailored to Chinese patients with deep vein thrombosis (DVT). A nonlinear mixed-effects modeling approach was employed using Phoenix NLME 7.0 software to construct the PPK model for rivaroxaban. The PK of rivaroxaban was adequately characterized through a one-compartment model. Monte Carlo simulations were employed to formulate dosing guidelines applicable to different patient subgroups. Data from 60 Chinese DVT patients yielded 217 rivaroxaban plasma concentrations for analysis. The apparent clearance (CL/F) of rivaroxaban was found to be significantly influenced by the estimated glomerular filtration rate (eGFR), identified as a major covariate. Based on Monte Carlo simulations, for the acute DVT treatment, a regimen of 15 mg, 10 mg, or 5 mg twice daily was associated with the highest total probability target attainment (PTAtotal) in patients with normal, mildly impaired, or moderately impaired renal function, respectively. For the continued DVT treatment, a regimen of 20 mg, 15 mg, or 5 mg once daily exhibited the maximum PTAtotal in patients with normal, mildly impaired, or moderately impaired renal function, respectively. The recommendation label dose achieved the PK target in those with normal renal function. However, for patients with mild or moderate renal impairment, dose adjustments below the label recommendation might be necessary. The PPK model associated CL/F with the covariate eGFR. Utilizing the PPK model, a dosage regimen table was constructed to offer tailored dosing recommendations for Chinese DVT patients.

Diabetic Retinopathy and Chronic Kidney Disease: Associations and Comorbidities in a Large Diabetic Population - The Tongren Health Care Study

INTRODUCTION

The aim of the study was to investigate associations between diabetic retinopathy (DR) and chronic kidney disease (CKD) in patients with type 2 diabetes (TD2).

METHODS

The participants of the cross-sectional, community-based Tongren Health Care Study underwent a detailed medical and ophthalmological examination. We defined TD2 by a fasting plasma glucose concentration of ≥7.0 mmol/L or a medical history. CKD was classified as either reduced estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 mm2 or presence of albuminuria. DR was assessed using color fundus photographs.

RESULTS

Out of 62,217 participants of the Tongren Health Care Study, 5,103 (8.2%) patients had TD2. The prevalence of DR was 12.8% (95% CI, 11.8%, 13.7%), CKD was 13.3% (95% CI, 12.4%, 14.3%), and the subtypes of CKD including reduced eGFR and albuminuria was 4.6% (95% CI, 4.2%, 5.1%) and 10.1% (95% CI, 9.3%, 10.9%), respectively. DR was detectable in 21.0% of the patients with CKD, while CKD was present in 20.9% of the DR patients. Higher DR prevalence was associated with higher prevalence of albuminuria and reduced eGFR (both p < 0.05). Factors independently associated with the presence of CKD instead of DR were older age (p < 0.001, OR = 1.05), a higher body mass index (p < 0.001, OR = 1.14), a higher serum concentration of triglycerides (p < 0.001, OR = 1.26), and a lower blood glucose (p < 0.001, OR = 0.93). Having hypertension was additionally associated with the presence of reduced eGFR as compared with DR (p = 0.005, OR = 4.47).

CONCLUSIONS

TD2 patients of older age and with higher body mass index, hypertension, and dyslipidemia had a higher probability of being affected by CKD rather than DR, while those with a higher blood glucose level were more prone to DR than CKD.

Genome-wide association study and fine-mapping on Korean biobank to discover renal trait-associated variants

Background

Chronic kidney disease is a significant health burden worldwide, with increasing incidence. Although several genome-wide association studies (GWAS) have investigated single nucleotide polymorphisms (SNP) associated with kidney trait, most studies were focused on European ancestry.

Methods

We utilized clinical and genetic information collected from the Korean Genome and Epidemiology Study (KoGES).

Results

More than five million SNPs from 58,406 participants were analyzed. After meta-GWAS, 1,360 loci associated with estimated glomerular filtration rate (eGFR) at a genome-wide significant level (p = 5 × 10-8) were identified. Among them, 399 loci were validated with at least one other biomarker (blood urea nitrogen [BUN] or eGFRcysC) and 149 loci were validated using both markers. Among them, 18 SNPs (nine known ones and nine novel ones) with 20 putative genes were found. The aggregated effect of genes estimated by MAGMA gene analysis showed that these significant genes were enriched in kidney-associated pathways, with the kidney and liver being the most enriched tissues.

Conclusion

In this study, we conducted GWAS for more than 50,000 Korean individuals and identified several variants associated with kidney traits, including eGFR, BUN, and eGFRcysC. We also investigated functions of relevant genes using computational methods to define putative causal variants.

Effect of Two Cystatin C Reagents and Four Equations on Glomerular Filtration Rate Estimations After Standardization

Background

Serum cystatin C (cysC), which is less affected by sex, race, and muscle mass than creatinine, is a useful biomarker of the estimated glomerular filtration rate (eGFR). The standardization of cysC measurements remains controversial, although a certified reference material (ERM-DA471/IFCC) is available. Moreover, the effect of combinations of cysC reagents and equations for eGFR is unclear.

Methods

We conducted a simulation analysis of cysC measured using two reagents standardized against ERM-DA471/IFCC-Gentian cystatin C immunoassay (Gentian_cys; GentianAS, Moss, Norway) and Roche Tina-quant Cystatin C Gen.2 (Roche_cys; Roche, Mannheim, Germany)-on a Cobas c702 system (Roche) and eGFR generated by eight combinations of four equations: 2012 cystatin C-based Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI_cys); the Caucasian, Asian, pediatric, and adult equation (CAPA_eq); full age spectrum equation (FAS_eq); and 2023 cystatin C-based European Kidney Function Consortium equation (EKFC_cys).

Results

A total of 148 participants (mean age, 60.5±14.5 years; 43% female) were enrolled. The mean cysC was 1.72±1.44 mg/L for Gentian_cys and 1.71±1.35 mg/L for Roche_cys. Regression analysis showed concordance between the reagents within 0.85-4.40 mg/L when using ±7.61% total allowable error. Lin's concordance correlation coefficient of eGFR, by combining the measuring system and equation, varied from 0.73 to 1.00.

Conclusions

The equivalence of cysC values at low concentrations (<0.85 mg/L) between the two reagents was unsatisfactory. Results obtained with different measurement systems could lead to larger differences in eGFR varying with the combination.

Association of clinical characteristics with urine uromodulin in children with chronic kidney disease

BACKGROUND

Uromodulin is the most abundant protein in the urine of healthy adults, and higher urine concentrations mark better tubular health. Greater kidney size and function are predictors of higher uromodulin levels in adults. Urine uromodulin has not yet been studied in children with chronic kidney disease (CKD). Thus, we sought to determine the relationship between age and kidney function with urine uromodulin levels in children with CKD.

METHODS

In the CKD in Children (CKiD) cohort, we utilized multivariable linear regression to evaluate the relationship of age and eGFR with urine uromodulin levels. The primary outcome was uromodulin indexed to urine creatinine (Umod/Cr, mg/g), which was log2-transformed given its skewed distribution.

RESULTS

Among 677 CKiD participants, the median age was 11.8 years (8.2-15.3), the median eGFR was 49 ml/min/1.73 m2 (37-63), the etiology of CKD was glomerular disease in 31%, and the median Umod/Cr level was 0.114 mg/g (0.045-0.226). In the multivariable models, each one-year older age was associated with 0.18 (12%) lower log2(Umod/Cr) and 0.20 (13%) lower log2(Umod/Cr) among those with non-glomerular and glomerular disease, respectively (p < 0.001). However, we did not find a statistically significant association between eGFR and Umod/Cr in either participants with non-glomerular or glomerular disease (p = 0.13 and p = 0.58, respectively).

CONCLUSIONS

Among children with CKD, older age is significantly associated with lower Umod/Cr, independent of eGFR. Further studies are needed to comprehensively evaluate age-specific reference ranges for urine uromodulin and to evaluate the longitudinal relationship of uromodulin with both age and eGFR in children with CKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Association of Chronic Kidney Disease with Cardiovascular Disease in Cancer Patients: A Cross-Sectional Study

INTRODUCTION

Due to the cardiotoxicity of cancer treatment and traditional risk factors for cardiovascular disease (CVD) such as obesity, diabetes, dyslipidemia, and hypertension, cancer patients are at higher risk of developing CVD. However, limited research exists on the correlation between chronic kidney disease (CKD) and CVD risk in cancer patients.

METHODS

This cross-sectional study selected cancer patients aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES) conducted from 2015 to 2020. Multivariable logistic regression was used to assess the association between CKD and CVD in cancer patients. Additionally, subgroup analyses were conducted to investigate the association among different groups of cancer patients.

RESULTS

We included 1,700 adult cancer patients (52.53% were females). After multivariable adjustment for covariates including traditional CVD factors, CKD was significantly associated with CVD, with an odds ratio (95% confidence interval) and p value of 1.61 (1.18, 2.19) and 0.004. Subgroup analyses after multivariable adjustment showed a significant correlation between CKD and increased CVD risk in the following cancer patients: age ≥60 years, males, white ethnicity, and individuals with or without traditional CVD factors (obesity, diabetes, dyslipidemia, and hypertension).

CONCLUSIONS

CKD remains a significant factor in the higher risk of CVD among adult cancer patients in the United States, even after adjustment for traditional CVD risk factors. Therefore, to reduce the risk of CVD in cancer patients, it is important to treat CKD as a non-traditional risk factor for CVD and actively manage it.

Clopidogrel-Related High Residual Platelet Reactivity Associated with Estimated Glomerular Filtration Rate in Patients with Acute Ischemic Stroke

INTRODUCTION

There are few studies on the relationship between the occurrence of clopidogrel-related high residual platelet reactivity (HRPR) and estimated glomerular filtration rate (eGFR) at admission in patients with ischemic stroke. The aim of this study was to investigate the possible relationship between the two.

METHODS

Patients who were hospitalized and diagnosed with acute ischemic stroke were recruited from July 1, 2017, to June 30, 2018, at Shanghai TCM-Integrated Hospital. Renal function was measured within 24 h of enrollment and eGFR was calculated. Patients were tested for platelet reactivity using the VerifyNow system after 7 days of antiplatelet therapy with clopidogrel 75 mg/d alone, and patients with P2Y12 reaction unit values ≥230 were diagnosed with HRPR. The association between HRPR and eGFR was analyzed.

RESULTS

A total of 274 patients were enrolled in the study, of whom 91 (33.21%) had HRPR. Multivariate logistic regression analysis suggested that an increased risk of HRPR was independently associated with female sex and reduced eGFR (female sex: OR = 2.24, 95% CI: 1.26-3.99, p = 0.006; mild chronic kidney disease [CKD]: OR = 2.95, 95% CI: 1.47-5.93, p = 0.002; moderate CKD: OR = 3.07, 95% CI: 1.08-8.75, p = 0.04).

CONCLUSION

Decreased eGFR is an independent risk factor for the occurrence of HRPR in patients with ischemic stroke.

Examine the optimal multidisciplinary care teams for patients with chronic kidney disease from a nationwide cohort study

Background

Multidisciplinary team-based integrated care (MDC) has been recommended for patients with chronic kidney disease (CKD). However, team-based specific structured care systems are not yet established. Therefore, we investigated the efficacy of MDC system and the optimal number of professionals that make up the team for maintaining kidney function and improving prognosis.

Methods

This nationwide, multicenter, observational study included 2,957 Japanese patients with CKD who received MDC from 2015 to 2019. The patients were divided into four groups according to the number of professionals in the MDC team. Groups A, B, C, and D included nephrologists and one, two, three, and four or more other professionals, respectively. Changes in the annual decline in estimated glomerular filtration rate before and after MDC were evaluated. Cox regression was utilized to estimate the correlation between each group and all-cause mortality and the start of renal replacement therapy (RRT) for 7 years.

Results

The change in eGFR significantly improved between before and at 6, 12, and 24 months after MDC in all groups (all p < 0.0001). Comparing group D to group A (reference), the hazard ratio (HR) for all-cause mortality and the start of the RRT was 0.60 (95% confidence interval, 0.48-0.73; p < 0.0001) after adjustment for multiple confounders. Lower HR in group D was confirmed in both diabetes and nondiabetes subgroups.

Conclusion

An MDC team comprised of five or more professionals might be associated with improvements in mortality and kidney prognosis. Furthermore, MDC might be effective for treating CKD other than diabetes.

The prognostic value of estimated glomerular filtration rate on admission for death within 30 days among COVID-19 inpatients using fractional polynomial and spline smoothing

BACKGROUND

The common regression models included estimated glomerular filtration rate (eGFR) in the continuous and categorical form for predicting the mortality in COVID-19 inpatients. However, the relationship may be non-linear, and categorizing implies a loss of information. This study aimed to assess the effect of eGFR on admission on death within 30 days among COVID-19 inpatients using flexible and smooth transformations of eGFR and compare the results against the common models.

METHODS

A retrospective study was conducted on hospitalized COVID-19 patients between April 2019 and July 2019 in Hamadan, Western Iran. The effect of eGFR on the death within 30 days was evaluated using different modeling: categorization, linear, unrestricted cubic spline (USC) with 4 knots, and fractional polynomial (FP). The results adjusted for older age and intensive care unit (ICU) admission. Discrimination power and model performance of the best-fitting model was evaluated using the area under the ROC (AUROC) and Brier score.

RESULTS

In total, 2945 patients (median age 61 years; interquartile range 48-73 years) were included, of whom the mortality rate was 9.23%. The relationship between the eGFR and death within 30 days is non-linear, so the degree-2 FP with powers (- 2, - 1) is the best-fitting model. Using the FP model, the risk increased exponentially in eGFR < 45 and then increased linearly and slowly. The AUROC of the FP model involving eGFR, older age, and ICU admission was 0.92 (95% CI 0.90-0.93) with a Brier score of 0.09.

CONCLUSION

There is a non-linear and asymmetric relationship between eGFR and death within 30 days among COVID-19 inpatients. Kidney function can be measured in COCID-19 patients on admission to know better understanding about prognosis of the patients.

Association between weight-adjusted-waist index and chronic kidney disease: a cross-sectional study

AIMS

We aimed to investigate the potential association between weight-adjusted-waist index (WWI) and chronic kidney disease (CKD).

DESIGN AND METHODS

This research examined data collected from the National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2020. CKD was defined as the low estimated glomerular filtration rate (eGFR) or the existence of albuminuria (urinary albumin-to-creatinine ratio (ACR) ≥ 30mg/g). Low-eGFR was described as eGFR < 60 mL/min/1.73m2. The associations between WWI with CKD, albuminuria, and low-eGFR were examined using generalized additive models and weighted multivariable logistic regression models. We also analyzed the associations of other obesity indicators with CKD, albuminuria, and low-eGFR, including body mass index (BMI), waist-to-height ratio (WHtR), waist circumference(WC), height, and weight. The receiver operating characteristic (ROC) curves were used to assess and compare their diagnostic abilities.

RESULTS

Males made up 48.26% of the total 40,421 individuals that were recruited. The prevalences of CKD, albuminuria, and low-eGFR were 16.71%, 10.97%, and 7.63%, respectively. WWI was found to be positively linked with CKD (OR = 1.42; 95% CI: 1.26, 1.60). A nonlinear connection between WWI and CKD was found using smooth curve fitting. Additionally, a higher prevalence of albuminuria is linked to a higher level of WWI (OR = 1.60; 95% CI: 1.40, 1.82). Different stratifications did not substantially influence the connection between WWI and CKD, albuminuria, and low-eGFR, according to subgroup analysis and interaction tests. We observed higher height was related to higher low-eGFR prevalence (OR = 1.05; 95% CI: 1.03, 1.06). ROC analysis revealed that WWI had the best discrimination and accuracy for predicting CKD and albuminuria compared to other obesity indicators (BMI, WHTR, WC, height and weight). In addition, height had the highest area under the curve (AUC) value for predicting low-eGFR.

CONCLUSION

WWI is the best obesity indicator to predict CKD and albuminuria compared to other obesity indicators (BMI, WHTR, WC, height, and weight). WWI and CKD and albuminuria were found to be positively correlated. Furthermore, height had the strongest ability to predict low-eGFR. Therefore, the importance of WWI and height in assessing kidney health in US adults should be emphasized.

Variation of eGFR reporting and CKD equations used in the United Kingdom

BACKGROUND

UK Clinical laboratories have been routinely reporting an estimated glomerular filtration rate (eGFR) based on creatinine measurements using an eGFR equation since the early 2000s. Though there have been recommendations to use enzymatic based creatinine assays, and a recommendation of which equation to use, there still remains a high degree of variation in calculated eGFR results.

METHODS

Data from the UK NEQAS for Acute and Chronic Kidney Disease Scheme have been reviewed to look at the CKD equations that are currently in use in the UK and the impact on eGFR results reported. The UK NEQAS for Acute and Chronic Kidney Disease has over 400 participants measuring creatinine across all major clinical biochemistry platforms.

RESULTS

An audit of EQA registration against results returned showed that in February 2022 at most 44% of registered participants were correctly reporting the 2009 CKD-EPI equation. At higher creatinine concentrations (which give rise to lower eGFR results), the spread of eGFRs is tight and there is little difference between results from different method principles. However, at lower creatinine concentrations, where it is known that there is more variation in creatinine depending on method choice, both method principle and eGFR equation choice can influence calculated eGFR. In some cases, this can impact CKD Stage classification.

CONCLUSIONS

CKD is a serious public health issue that requires accurate assessment of eGFR. Laboratories should be in constant dialogue with their renal teams about their creatinine assay performance and impact on eGFR reporting across their service.

Prognostic role of the neutrophil-to-lymphocyte ratio in patients with chronic kidney disease

BACKGROUND/AIMS

The neutrophil-to-lymphocyte ratio (NLR) has a prognostic value in cardiovascular disease, infection, inflammatory disease, and several malignancies. Therefore, the NLR has a possible predictive value in patients with chronic kidney disease (CKD), but this predictive value has not been validated. Here, we aimed to investigate the possibility of NLR as a predictor of CKD progression.

METHODS

This retrospective observational study included 141 patients with non-dialysis CKD. The participants were divided into terciles (T1, T2, and T3) according to NLR. The primary outcome was defined as a composite kidney event, which included a decline in the estimated glomerular filtration rate (eGFR) of at least 50% or initiation of renal replacement therapy during the follow-up period.

RESULTS

The mean follow-up duration was 5.45 ± 2.11 years. The mean NLRs were 1.35 ± 0.05 in T1 (n = 47), 2.16 ± 0.04 in T2 (n = 47), and 4.29 ± 0.73 in T3 (n = 47). The group with the highest NLR (T3) had higher baseline CKD and serum creatinine and lower eGFR levels than the group with the lowest NLR (T1). The cumulative incidence rate of composite kidney events was significantly higher in T3 compared with T1 (p < 0.001, log-rank test). Cox regression analysis revealed that high NLR was associated with the risk of composite kidney events (adjusted hazard ratio, 3.33; 95% confidence interval, 1.43-7.76).

CONCLUSION

A higher NLR reflects the more advanced stage of CKD and suggests a role for NLR as a biomarker for predicting CKD progression.