Kidney disease progression and all-cause mortality across estimated glomerular filtration rate and albuminuria categories among patients with vs. without type 2 diabetes

Clinical Outcomes in Patients with CKD and Rapid or Non-rapid eGFR Decline: A Report from the DISCOVER CKD Retrospective Cohort

INTRODUCTION

This analysis examined the baseline characteristics and clinical outcomes of patients with chronic kidney disease (CKD) and rapid or non-rapid estimated glomerular filtration rate (eGFR) decline, using retrospective data from DISCOVER CKD (ClinicalTrials.gov, NCT04034992).

METHODS

Data (2008-2020) were extracted from UK Clinical Practice Research Datalink, US TriNetX, US Limited Claims and Electronic Health Record Dataset, and Japan Medical Data Vision. Patients with CKD (two consecutive eGFR measures < 75 mL/min/1.73 m2 recorded 90-730 days apart) were included. Rapid eGFR decline was defined as an annual decline of > 4 mL/min/1.73 m2 at 2 years post-index; non-rapid eGFR decline was defined as an annual decline of ≤ 4 mL/min/1.73 m2. Clinical outcomes assessed included all-cause mortality, kidney outcomes (composite risk of kidney failure [progression to CKD stage 5] or > 50% eGFR decline, and kidney failure alone), cardiovascular events-including major adverse cardiovascular events (MACE; non-fatal myocardial infarction/stroke and cardiovascular death)-and all-cause hospitalization.

RESULTS

Across databases, rapid eGFR decline occurred in 13.7% of 804,237 eligible patients. Mean annual eGFR decline ranged between - 6.21 and - 6.86 mL/min/1.73 m2 in patients with rapid eGFR decline versus between - 0.11 and - 0.77 mL/min/1.73 m2 in patients with non-rapid eGFR decline. Rapid eGFR decline was associated with increased comorbidity burden and medication prescriptions. Across databases, the composite risk of kidney failure or > 50% decline in eGFR was significantly greater in patients with rapid versus non-rapid eGFR decline (P < 0.01); all-cause mortality, kidney failure alone, MACE, and all-cause hospitalization each significantly increased in two databases (P < 0.01-0.05).

CONCLUSION

Understanding patient factors associated with rapid eGFR decline in patients with CKD may help identify individuals who would benefit from proactive management to minimize the risk of adverse outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04034992.

Body mass index modifies the effect of urinary protein-to-creatinine ratio on chronic kidney disease progression

BACKGROUND

This study aimed to determine the association between the urinary protein-to-creatinine ratio (UPCR) and chronic kidney disease (CKD) progression in a cohort study, and to determine whether body mass index (BMI) modifies this association.

METHODS

The study population consisted of 856 hypertensive patients with CKD stages 2-5, enrolled between 2010 and 2011 in Japan. Generalized linear models with a logit link were used to evaluate the independent and combined effects of the UPCR and BMI on CKD progression RESULTS: During a median follow-up of 25 months, 242 patients developed CKD progression during follow-up. A notably higher risk of CKD progression was found in participants in tertiles 2 [odds ratio (OR): 5.46, 95% confidence interval (95% CI): 2.49-11.99] and 3 (OR 27.74, 95% CI 12.34-62.38) comparing with tertiles 1 for UPCR levels. Moreover, an interaction was found between UPCR and BMI on CKD progression (P for interaction = 0.006). Participants in both the highest tertile of UPCR and overweight (UPCR ≥ 248.9 mg/mmol and BMI ≥ 25 kg/m2) had a 45.59-times higher risk of CKD progression compared with those in the lowest tertile of UPCR and nonoverweight (UPCR < 36.2 mg/mmol and BMI < 25 kg/m2) CONCLUSIONS: The present study demonstrates that the combination of elevated UPCR and BMI may contribute to an increased risk of CKD progression.

Effects of Empagliflozin in Type 2 Diabetes With and Without Chronic Kidney Disease and Nondiabetic Chronic Kidney Disease: Protocol for 3 Crossover Randomized Controlled Trials (SiRENA Project)

BACKGROUND

Sodium-glucose-cotransporter 2 inhibitors (SGLT2is) have revolutionized the treatment of type 2 diabetes mellitus (DM2) and chronic kidney disease (CKD), reducing the risk of cardiovascular and renal end points by up to 40%. The underlying mechanisms are not fully understood.

OBJECTIVE

The study aims to examine the effects of empagliflozin versus placebo on renal hemodynamics, sodium balance, vascular function, and markers of the innate immune system in patients with DM2, DM2 and CKD, and nondiabetic CKD.

METHODS

We conducted 3 double-blind, crossover, randomized controlled trials, each with identical study protocols but different study populations. We included patients with DM2 and preserved kidney function (estimated glomerular filtration rate >60 mL/min/1.73 m2), DM2 and CKD, and nondiabetic CKD (both with estimated glomerular filtration rate 20-60 mL/min/1.73 m2). Each participant was randomly assigned to 4 weeks of treatment with either 10 mg of empagliflozin once daily or a matching placebo. After a wash-out period of at least 2 weeks, participants were crossed over to the opposite treatment. End points were measured at the end of each treatment period. The primary end point was renal blood flow measured with 82Rubidium positron emission tomography-computed tomography (82Rb-PET/CT). Secondary end points include glomerular filtration rate measured with 99mTechnetium-diethylene-triamine-pentaacetate (99mTc-DTPA) clearance, vascular function assessed by forearm venous occlusion strain gauge plethysmography, measurements of the nitric oxide (NO) system, water and sodium excretion, body composition measurements, and markers of the complement immune system.

RESULTS

Recruitment began in April 2021 and was completed in September 2022. Examinations were completed by December 2022. In total, 49 participants completed the project: 16 participants in the DM2 and preserved kidney function study, 17 participants in the DM2 and CKD study, and 16 participants in the nondiabetic CKD study. Data analysis is ongoing. Results are yet to be published.

CONCLUSIONS

This paper describes the rationale, design, and methods used in a project consisting of 3 double-blind, crossover, randomized controlled trials examining the effects of empagliflozin versus placebo in patients with DM2 with and without CKD and patients with nondiabetic CKD, respectively.

TRIAL REGISTRATION

EU Clinical Trials Register 2019-004303-12; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2019-004303-12, EU Clinical Trials Register 2019-004447-80; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2019-004447-80, EU Clinical Trials Register 2019-004467-50; https://www.clinicaltrialsregister.eu/ctr-search/search?query=and+2019-004467-50.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/56067.

Endothelin receptor antagonists in diabetic and non-diabetic chronic kidney disease

Chronic kidney disease (CKD) is one of the major causes of morbidity and mortality, affecting >800 million persons globally. While we still lack efficient, targeted therapies addressing the major underlying pathophysiologic processes in CKD, findings of several recent trials have brought about a shifting landscape of promising therapies. The endothelin system has been implicated in the pathophysiology of CKD and endothelin receptor antagonists are one class of drugs for which we have increasing evidence of efficacy in these patients. In this review we summarize the most recent findings on the safety and efficacy of endothelin receptor antagonists in diabetic and non-diabetic CKD, future directions of research and upcoming treatments.

Assessing trends and variability in outpatient dual testing for chronic kidney disease with urine albumin and serum creatinine, 2009-2018: a retrospective cohort study in the Veterans Health Administration System

BACKGROUND

Simultaneous urine testing for albumin (UAlb) and serum creatinine (SCr), that is, 'dual testing,' is an accepted quality measure in the management of diabetes. As chronic kidney disease (CKD) is defined by both UAlb and SCr testing, this approach could be more widely adopted in kidney care.

OBJECTIVE

We assessed time trends and facility-level variation in the performance of outpatient dual testing in the integrated Veterans Health Administration (VHA) system.

DESIGN, SUBJECTS AND MAIN MEASURES

This retrospective cohort study included patients with any inpatient or outpatient visit to the VHA system during the period 2009-2018. Dual testing was defined as UAlb and SCr testing in the outpatient setting within a calendar year. We assessed time trends in dual testing by demographics, comorbidities, high-risk (eg, diabetes) specialty care and facilities. A generalised linear mixed-effects model was applied to explore individual and facility-level predictors of receiving dual testing.

KEY RESULTS

We analysed data from approximately 6.9 million veterans per year. Dual testing increased, on average, from 17.4% to 21.2%, but varied substantially among VHA centres (0.3%-43.7% in 2018). Dual testing was strongly associated with diabetes (OR 10.4, 95% CI 10.3 to 10.5, p<0.0001) and not associated with VHA centre complexity level. However, among patients with high-risk conditions including diabetes, <50% received dual testing in any given year. As compared with white veterans, black veterans were less likely to be tested after adjusting for other individual and facility characteristics (OR 0.93, 95% CI 0.92 to 0.93, p<0.0001).

CONCLUSIONS

Dual testing for CKD in high-risk specialties is increasing but remains low. This appears primarily due to low rates of testing for albuminuria. Promoting dual testing in high-risk patients will help to improve disease management and patient outcomes.

Impact of Sodium-Glucose Cotransporter-2 Inhibitors in the Management of Chronic Kidney Disease: A Middle East and Africa Perspective

Chronic kidney disease (CKD) is a major public health concern in the Middle East and Africa (MEA) region and a leading cause of death in patients with type 2 diabetes mellitus (T2DM) and hypertension. Early initiation of sodium-glucose cotransporter - 2 inhibitors (SGLT-2i) and proper sequencing with renin-angiotensin-aldosterone system inhibitors (RAASi) in these patients may result in better clinical outcomes due to their cardioprotective properties and complementary mechanisms of action. In this review, we present guideline-based consensus recommendations by experts from the MEA region, as practical algorithms for screening, early detection, nephrology referral, and treatment pathways for CKD management in patients with hypertension and diabetes mellitus. This study will help physicians take timely and appropriate actions to provide better care to patients with CKD or those at high risk of CKD.

Associations Between Albuminuria and Mortality Among US Adults by Demographic and Comorbidity Factors

Background Albuminuria is a known marker of mortality risk. Whether the association between albuminuria and mortality differs by demographic and comorbidity factors remains unclear. Therefore, we sought to determine whether albuminuria is differentially associated with mortality. Methods and Results This study included 49 640 participants from the National Health and Nutrition Examination Survey (1999-2018). All-cause mortality through 2019 was linked from the National Death Index. Multivariable-adjusted Poisson regression models were used to determine whether levels of urine albumin-to-creatinine ratio (ACR) were associated with mortality. Models were adjusted for demographic, socioeconomic, behavioral, and clinical factors. Mean age in the population was 46 years, with 51.3% female, and 30.3% with an ACR ≥10 mg/g. Over a median follow-up of 9.5 years, 6813 deaths occurred. Compared with ACR <10, ACR ≥300 was associated with increased risk of mortality by 132% overall (95% CI, 2.01-2.68), 124% among men (95% CI, 1.84-2.73), 158% among women (95% CI, 2.14-3.11), 130% among non-Hispanic White adults (95% CI: 1.89-2.79), 135% among non-Hispanic Black adults (95% CI, 1.82-3.04), and 114% among Hispanic adults (95% CI, 1.55-2.94). Compared with ACR <10, ACR ≥300 was associated with increased risk of mortality by 148% among individuals with neither hypertension nor hypercholesterolemia (95% CI, 1.69-3.64), 128% among individuals with hypertension alone (95% CI, 1.86-2.79), and 166% among individuals with both hypertension and hypercholesterolemia (95% CI, 2.18-3.26). Conclusions We found strong associations between albuminuria and mortality risk, even at mildly increased levels of albuminuria. Associations persisted across categories of sex, race or ethnicity, and comorbid conditions, with subtle differences.

Association between estimated glomerular filtration rate slope and cardiovascular disease among individuals with and without diabetes: a prospective cohort study

BACKGROUND

Previous studies have reported an association between a significant decline in estimated glomerular filtration rate (eGFR) over time and an increased risk of cardiovascular disease (CVD). This study aimed to investigate the association between the eGFR slope and CVD among individuals with and without diabetes.

METHODS

This prospective cohort study was conducted within the Tehran Lipid and Glucose Study (TLGS) framework. We studied 6919 adults aged 20-70 years, including 985 with diabetes and 5934 without diabetes. The eGFR slope was determined based on repeated measurements of eGFR through linear mixed-effects models. A multivariable Cox proportional hazard model was employed to evaluate the association between eGFR slope, both in continuous and categorical form, and the risk of CVD.

RESULTS

The slopes of eGFR exhibited a bell-shaped distribution, with a mean (standard deviation (SD)) of -0.63 (0.13) and - 0.70 (0.14) ml/min per 1.73 m2 per year in individuals with and without diabetes, respectively. During a median follow-up of 8.22 years, following the 9-year eGFR slope ascertainment period, a total of 551 CVD events (195 in patients with diabetes) were observed. Among individuals with diabetes, a steeper decline in eGFR slope was significantly associated with a higher risk of CVD events, even after adjusting for baseline eGFR, demographic factors, and traditional risk factors for CVD; slopes of (-1.05 to -0.74) and (-0.60 to -0.52) were associated with 2.12 and %64 higher risks for CVD, respectively, compared with a slope of (-0.51 to 0.16). Among individuals without diabetes, the annual eGFR slope did not show a significant association with the risk of CVD.

CONCLUSION

Monitoring the eGFR slope may serve as a potential predictor of CVD risk in individuals with diabetes.

Clinical outcomes in patients with type 2 diabetes mellitus-related kidney disease: A Jordanian population cohort study

BACKGROUND

Diabetic kidney disease (DKD) increases the risk of cardiovascular (CV) complications, kidney disease progression, and mortality. We aimed to determine the incidence and risk of these outcomes according to DKD phenotype among the Jordanian population.

METHODS

A total of 1172 type 2 diabetes mellitus patients with estimated glomerular filtration rates (eGFRs) of >30 ml/min/1.73 m² were followed-up from 2019 to 2022. At baseline, patients were classified according to the presence of albuminuria (>30 mg/g creatinine) and reduced eGFR (<60 ml/min/1.73 m²) into four phenotypes: non-DKD (reference category), albuminuric DKD without decreased eGFR, non-albuminuric DKD with decreased eGFR, and albuminuric DKD with decreased eGFR.

RESULTS

Mean follow-up was 2.9 ± 0.4 years. Overall, 147 patients (12.5 %) experienced CV events, while 61 (5.2 %) demonstrated kidney disease progression (eGFR: <30 ml/min/1.73 m²). The mortality rate was 4.0 %. Multivariable-adjusted risk for CV events and mortality was greatest for the albuminuric DKD with decreased eGFR group (hazard ratio [HR]: 1.45, 95 % confidence interval [CI]: 1.02-2.33 and HR: 6.36, 95 % CI: 2.98-13.59, respectively), with the risk increasing when adjusted for prior CV history (HR: 1.47, 95 % CI: 1.06-3.42 and HR: 6.70, 95 % CI: 2.70-16.60, respectively). Risk of a ≥40 % decline in eGFR was greatest for the albuminuric DKD with decreased eGFR group (HR: 3.45, 95 % CI: 1.74-6.85), followed by the albuminuric DKD without decreased eGFR group (HR: 1.6, 95 % CI: 1.06-2.75).

CONCLUSION

Thus, patients with albuminuric DKD and decreased eGFR were at greater risk for poor CV, renal, and mortality outcomes compared to other phenotypes.

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

Nontraditional Risk Factors for Progression Through Chronic Kidney Disease Risk Categories: The Coronary Artery Risk Development in Young Adults Study

BACKGROUND

There may be nontraditional pathways of chronic kidney disease (CKD) progression that are complementary to classical pathways. Therefore, we aimed to examine nontraditional risk factors for incident CKD and its progression.

METHODS

We used the generally healthy population (n = 4382) starting at age 27-41 years in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, which is an observational longitudinal study. Nontraditional risk factors included forced vital capacity, inflammation, serum urate, and serum carotenoids. CKD risk category was classified using the estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) measured in 1995-1996 and repeated every 5 years for 20 years: No CKD, low risk, moderate risk, high risk, and very high risk.

RESULTS

At baseline, 84.8% had no CKD (eGFR ≥60 mL/min/1.73 m2 and UACR <10 mg/g), 10.3% were in the low risk (eGFR ≥60 and UACR 10-29), and 4.9% had CKD (eGFR <60 and/or UACR ≥ 30). Nontraditional risk factors were significantly associated with the progression of CKD to higher categories. Hazard ratios per standard deviation of the predictor for incident CKD and its progression from the No CKD and low and moderate risk into CKD were inverse for forced vital capacity and serum carotenoids and positive for serum urate, GlycA, and C-reactive protein, the first 3 even after adjustment for conventional risk factors.

CONCLUSION

Several nontraditional markers were significantly associated with an increased risk of progression to higher CKD categories in generally healthy young to middle-aged adults.

Cadmium-Induced Proteinuria: Mechanistic Insights from Dose-Effect Analyses

Cadmium (Cd) is a toxic metal that accumulates in kidneys, especially in the proximal tubular epithelial cells, where virtually all proteins in the glomerular ultrafiltrate are reabsorbed. Here, we analyzed archived data on the estimated glomerular filtration rate (eGFR) and excretion rates of Cd (E_Cd), total protein (E_Prot), albumin (E_alb), β₂-microglobulin (E_β2M), and α1-microglobulin (E_α1M), which were recorded for residents of a Cd contamination area and a low-exposure control area of Thailand. Excretion of Cd and all proteins were normalized to creatinine clearance (C_cr) as E_Cd/C_cr and E_Prot/C_cr to correct for differences among subjects in the number of surviving nephrons. Low eGFR was defined as eGFR ≤ 60 mL/min/1.73 m², while proteinuria was indicted by E_Pro/C_cr ≥ 20 mg/L of filtrate. E_Prot/C_cr varied directly with E_Cd/C_cr (β = 0.263, p < 0.001) and age (β = 0.252, p < 0.001). In contrast, eGFR values were inversely associated with E_Cd/C_cr (β = -0.266, p < 0.001) and age (β = -0.558, p < 0.001). At E_Cd/C_cr > 8.28 ng/L of filtrate, the prevalence odds ratios for proteinuria and low eGFR were increased 4.6- and 5.1-fold, respectively (p < 0.001 for both parameters). Thus, the eGFR and tubular protein retrieval were both simultaneously diminished by Cd exposure. Of interest, E_Cd/C_cr was more closely correlated with E_Prot/C_cr (r = 0.507), E_β2M (r = 0.430), and E_α1M/C_cr (r = 0.364) than with E_Alb/C_cr (r = 0.152). These data suggest that Cd may differentially reduce the ability of tubular epithelial cells to reclaim proteins, resulting in preferential reabsorption of albumin.

Cardiovascular events and mortality in chronic kidney disease in primary care patients with previous type 2 diabetes and/or hypertension. A population-based epidemiological study (KIDNEES)

BACKGROUND

Chronic Kidney Disease (CKD), Type 2 Diabetes (T2D) and Hypertension (HTN) are frequently associated with adverse outcomes. We aimed to estimate the impact of a prior diagnosis of T2D and/or HTN on clinical characteristics, cardiovascular events (CVE) and all-cause mortality (ACM) of patients with CKD.

METHODS

We conducted a retrospective cohort study based on primary care electronic health records of people without atherosclerotic cardiovascular disease, aged 18-90 years with incident CKD between January 1, 2007, and December 31, 2017. The association between CKD groups classified according to prior diagnosis of T2D and/or HTN and risk of ACM and CVE at follow-up was evaluated with Cox and Fine-Gray regression models, respectively.

RESULTS

398,477 patients were included. Median age was 74 years and 55.2% were women. Individuals were classified as CKD with HTN (51.9%), CKD with T2D (3.87%), CKD with HTN/T2D (31.4%) and CKD without HTN/T2D (12.9%). In the multivariate analysis, with the CKD without HTN/T2D group as reference, the ACM Hazard Ratio (HR) was 0.74 (95%CI 0.72-0.75) for the CKD with HTN group, 0.81 (95%CI 0.79-0.83) for CKD with HTN/T2D and 1.14 (95%CI 1.10-1.19) for the CKD with T2D group. The sub distribution HRs for CVE were 1.40 (95%CI 1.34-1.47), 1.70 (95%CI 1.61-1.80) and 1.37 (95%CI 1.26-1.48), respectively.

CONCLUSION

In patients with CKD, the risk of ACM and CVE differed in patients with previous HTN and/or T2D. These comorbidities can help identify individuals at higher risk of adverse outcomes and improve the management of patients with CKD in primary care.

Progression of Chronic Kidney Disease Risk Categories and Risk of Cardiovascular Disease and Total Mortality: Coronary Artery Risk Development in Young Adults Cohort

Background Previous studies of worsening chronic kidney disease (CKD) based on declining estimated glomerular filtration rate (eGFR) or increasing urine albumin-creatinine ratio (UACR) are limited to later middle-age and older adults. We examined associations of CKD progression and incident cardiovascular disease (CVD) and mortality in younger adults. Methods and Results We studied 4382 adults in CARDIA (Coronary Artery Risk Development in Young Adults) initially aged 27 to 41 years and prospectively over 20 years. Five-year transition probabilities across CKD risk categories were based on eGFR and UACR measured at each exam. Proportional hazards models predicted incident CVD and all-cause mortality by time-varying CKD risk category, adjusting for demographics and CVD risk factors. Progression of CKD risk categories over 20 years occurred in 28.7% (1256/4382) of participants, driven by increases in UACR, but including 5.8% (n=255) with eGFR<60 mL/min per 1.73 m² or UACR ≥300 mg/g. Compared with eGFR ≥60 and UACR <10, demographic and smoking-adjusted hazard ratios for CVD were 1.62 (95% CI, 1.21-2.18) for low CKD risk (eGFR ≥60 with UACR 10-29) and 13.65 (95% CI, 7.52-24.79) for very high CKD risk (eGFR <30 or eGFR 30-44 with UACR 30-299; or eGFR 30-59 with UACR ≥300). Corresponding hazard ratios for all-cause mortality were 1.42 (95% CI, 1.08-1.88) and 14.75 (95% CI, 9.97-21.82). Although CVD associations were attenuated after adjustment for mediating CVD risk factors, all-cause mortality associations remained statistically significant. Conclusions Among young to middle-aged adults, progression to higher CKD risk category was common. Routine monitoring eGFR and UACR holds promise for prevention of CVD and total mortality.

The NOAEL Equivalent of Environmental Cadmium Exposure Associated with GFR Reduction and Chronic Kidney Disease

Cadmium (Cd) is a highly toxic metal pollutant present in virtually all food types. Health guidance values were established to safeguard against excessive dietary Cd exposure. The derivation of such health guidance figures has been shifted from the no-observed-adverse-effect level (NOAEL) to the lower 95% confidence bound of the benchmark dose (BMD), termed BMDL. Here, we used the PROAST software to calculate the BMDL figures for Cd excretion (E_Cd) associated with a reduction in the estimated glomerular filtration rate (eGFR), and an increased prevalence of chronic kidney disease (CKD), defined as eGFR ≤ 60 mL/min/1.73 m². Data were from 1189 Thai subjects (493 males and 696 females) mean age of 43.2 years. The overall percentages of smokers, hypertension and CKD were 33.6%, 29.4% and 6.2%, respectively. The overall mean E_Cd normalized to the excretion of creatinine (E_cr) as E_Cd/E_cr was 0.64 µg/g creatinine. E_Cd/E_cr, age and body mass index (BMI) were independently associated with increased prevalence odds ratios (POR) for CKD. BMI figures ≥24 kg/m² were associated with an increase in POR for CKD by 2.81-fold (p = 0.028). E_Cd/E_cr values of 0.38-2.49 µg/g creatinine were associated with an increase in POR for CKD risk by 6.2-fold (p = 0.001). The NOAEL equivalent figures of E_Cd/E_cr based on eGFR reduction in males, females and all subjects were 0.839, 0.849 and 0.828 µg/g creatinine, respectively. The BMDL/BMDU values of E_Cd/E_cr associated with a 10% increase in CKD prevalence were 2.77/5.06 µg/g creatinine. These data indicate that Cd-induced eGFR reduction occurs at relatively low body burdens and that the population health risk associated with E_Cd/E_cr of 2.77-5.06 µg/g creatinine was not negligible.

Association of Longitudinal Trajectories of Insulin Resistance With Adverse Renal Outcomes

OBJECTIVE

To analyze the relationship between time-serial changes in insulin resistance and renal outcomes.

RESEARCH DESIGN AND METHODS

A prospective cohort of subjects from the general population without chronic kidney disease (CKD) underwent a biennial checkup for 12 years (n = 5,347). The 12-year duration was divided into a 6-year exposure period, where distinct HOMA for insulin resistance (HOMA-IR) trajectories were identified using latent variable mixture modeling, followed by a 6-year event accrual period, from which the renal outcome data were analyzed. The primary end point was adverse renal outcomes, defined as a composite of estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 in two or more consecutive checkups or albumin ≥1+ on urine strip.

RESULTS

Two distinct groups of HOMA-IR trajectories were identified during the exposure period: stable (n = 4,770) and increasing (n = 577). During the event accrual period, 449 patients (8.4%) developed adverse renal outcomes, and the risk was higher in the increasing HOMA-IR trajectory group than in the stable group (hazard ratio 2.06, 95% CI 1.62-2.60, P < 0.001). The results were similar after adjustment for baseline clinical characteristics, comorbidities, anthropometric and laboratory findings, eGFR, and HOMA-IR. The clinical significance of increasing HOMA-IR trajectory was similar in three or four HOMA-IR trajectories. The increasing tendency of HOMA-IR was persistently associated with a higher incidence of adverse renal outcomes, irrespective of the prevalence of diabetes.

CONCLUSIONS

An increasing tendency of insulin resistance was associated with a higher risk of adverse renal outcomes. Time-serial tracking of insulin resistance may help identify patients at high risk for CKD.

The Lower Limit of Reference of Urinary Albumin/Creatinine Ratio and the Risk of Chronic Kidney Disease Progression in Patients With Type 2 Diabetes Mellitus

A urine albumin/creatinine ratio (UACR) <30 mg/g is considered to be normal, while increased risk of incident hypertension and cardiovascular disease mortality in subjects with high normal UACR level had been observed. However, a mild elevated but normal UACR level was associated with the risk of initiating chronic kidney disease (CKD) is uncertain. We investigated whether higher normal UACR is associated with the risk of developing CKD. A total of 4821 subjects with type 2 diabetes mellitus (T2DM), an estimated glomerular filtration rate >60 ml/min/1.73 m² and UACR <30 mg/g enrolled in a diabetes disease management program between 2006 and 2020 were studied. The optimal cutoff point for baseline UACR as a predictor for progression to CKD according to the 2012 KDIGO definition was calculated using receiving operating characteristic curve analysis. After a mean of 4.9 years follow-up, the CKD risk progression increased in parallel with the quartiles of baseline UACR <30 mg/g (p for trend <0.0001). UACR cutoff points of 8.44 mg/g overall, 10.59 mg/g in males and 8.15 mg/g in females were associated with the risk of CKD progression. In multivariate Cox regression analysis, the hazard ratios for the association between UACR (>8.44 mg/g, >10.9 mg/g, >8.15 mg/g in overall, male, and female patients, respectively) and the risk of CKD progression were significant. This study demonstrated that a cutoff UACR value of >10 mg/g could significantly predict the cumulative incidence and progression of CKD in patients with T2DM.

Astragaloside IV ameliorates diabetic nephropathy in db/db mice by inhibiting NLRP3 inflammasome‑mediated inflammation

Diabetic nephropathy (DN) is a primary cause of end‑stage renal disease. Despite the beneficial effects of astragaloside IV (AS)‑IV on renal disease, the underlying mechanism of its protective effects against DN has not been fully determined. The aims of the present study were to assess the effects of AS‑IV against DN in db/db mice and to explore the mechanism of AS‑IV involving the NLR family pyrin domain containing 3 (NLRP3), caspase‑1 and interleukin (IL)‑1β pathways. The 8‑week‑old db/db mice received 40 mg/kg AS‑IV once a day for 12 weeks via intragastric administration. Cultured mouse podocytes were used to further confirm the underlying mechanism in vitro. AS‑IV effectively reduced weight gain, hyperglycemia and the serum triacylglycerol concentration in db/db mice. AS‑IV also reduced urinary albumin excretion, urinary albumin‑to‑creatinine ratio and creatinine clearance rate, as well as improved renal structural changes, accompanied by the upregulation of the podocyte markers podocin and synaptopodin. AS‑IV significantly inhibited the expression levels of NLRP3, caspase‑1 and IL‑1β in the renal cortex, and reduced the serum levels of tumor necrosis factor (TNF)‑α and monocyte chemoattractant protein‑1. In high glucose‑induced podocytes, AS‑IV significantly improved the expression levels of NLRP3, pro‑caspase‑1 and caspase‑1, and inhibited the cell viability decrease in a dose‑dependent manner, while NLRP3 overexpression eliminated the effect of AS‑IV on podocyte injury and the inhibition of the NLRP3 and caspase‑1 pathways. The data obtained from in vivo and in vitro experiments demonstrated that AS‑IV ameliorated renal functions and podocyte injury and delayed the development of DN in db/db mice via anti‑NLRP3 inflammasome‑mediated inflammation.

Correction to: Kidney disease progression and all-cause mortality across estimated glomerular filtration rate and albuminuria categories among patients with vs. without type 2 diabetes

An amendment to this paper has been published and can be accessed via the original article.