The 10-Year Effects of Intensive Lifestyle Intervention on Kidney Outcomes

Rationale & Objective

Limited data exist on longitudinal kidney outcomes after nonsurgical obesity treatments. We investigated the effects of intensive lifestyle intervention on kidney function over 10 years.

Study Design

Post hoc analysis of Action for Health in Diabetes (Look AHEAD) randomized controlled trial.

Setting & Participants

We studied 4,901 individuals with type 2 diabetes and body mass index of ≥25 kg/m2 enrolled in Look AHEAD (2001-2015). The original Look AHEAD trial excluded individuals with 4+ urine dipstick protein, serum creatinine level of >1.4 mg/dL (women), 1.5 mg/dL (men), or dialysis dependence.

Exposures

Intensive lifestyle intervention versus diabetes support and education (ie, usual care).

Outcome

Primary outcome was estimated glomerular filtration rate (eGFR, mL/min/1.73 m2) slope. Secondary outcomes were mean eGFR, slope, and mean urine albumin to creatinine ratio (UACR, mg/mg).

Analytical Approach

Linear mixed-effects models with random slopes and intercepts to evaluate the association between randomization arms and within-individual repeated measures of eGFR and UACR. We tested for effect modification by baseline eGFR.

Results

At baseline, mean eGFR was 89, and 83% had a normal UACR. Over 10 years, there was no difference in eGFR slope (+0.064 per year; 95% CI: -0.036 to 0.16; P = 0.21) between arms. Slope or mean UACR did not differ between arms. Baseline eGFR, categorized as eGFR of <80, 80-100, or >100, did not modify the intervention's effect on eGFR slope or mean.

Limitations

Loss of muscle may confound creatinine-based eGFR.

Conclusions

In patients with type 2 diabetes and preserved kidney function, intensive lifestyle intervention did not change eGFR slope over 10 years. Among participants with baseline eGFR <80, lifestyle intervention had a slightly higher longitudinal mean eGFR than usual care. Further studies evaluating the effects of intensive lifestyle intervention in people with kidney disease are needed.

Associations between plasma metabolites and heavy metal exposure in residents of environmentally polluted areas

Heavy metals are commonly released into the environment through industrial processes such as mining and refining. The rapid industrialization that occurred in South Korea during the 1960s and 1970s contributed significantly to the economy of the country; however, the associated mining and refining led to considerable environmental pollution, and although mining is now in decline in South Korea, the detrimental effects on residents inhabiting the surrounding areas remain. The bioaccumulation of toxic heavy metals leads to metabolic alterations in human homeostasis, with disruptions in this balance leading to various health issues. This study used metabolomics to explore metabolomic alterations in the plasma samples of residents living in mining and refining areas. The results showed significant increases in metabolites involved in glycolysis and the surrounding metabolic pathways, such as glucose-6-phosphate, phosphoenolpyruvate, lactate, and inosine monophosphate, in those inhabiting polluted areas. An investigation of the associations between metabolites and blood clinical parameters through meet-in-the-middle analysis indicated that female residents were more affected by heavy metal exposure, resulting in more metabolomic alterations. For women, inhabiting the abandoned mine area, metabolites in the glycolysis and pentose phosphate pathways, such as ribose-5-phosphate and 3-phosphoglycerate, have shown a negative correlation with albumin and calcium. Finally, Mendelian randomization(MR) was used to determine the causal effects of these heavy metal exposure-related metabolites on heavy metal exposure-related clinical parameters. Metabolite biomarkers could provide insights into altered metabolic pathways related to exposure to toxic heavy metals and improve our understanding of the molecular mechanisms underlying the health effects of toxic heavy metal exposure.

Pediatric kidney dimensions and risk of persistent albuminuria in Mexican adolescents

In Mexico, chronic kidney disease of unknown origin is highly prevalent. Screening studies in adolescents have shown persistent microalbuminuria (pACR), adaptive podocytopathy and decreased kidney volume (KV). Here, we sought to develop normality tables of kidney dimensions by ultrasound in the Mexican state of Aguascalientes pediatric population (0 to 18y) and evaluate the relationship between the KV and pACR among the region's adolescents in a cross-sectional study. Kidney length (KL) and KV were determined by ultrasound. Our findings were compared with those in international literature of different populations where tables and graphs of normal kidney dimensions by ultrasound were reported. We compared organ dimensions in individuals above the age of 11 without albuminuria with those in patients with pACR recruited through screening studies in adolescents in Aguascalientes. This included 1068 individuals to construct percentile tables and graphs of the KL. Kidney dimensions were significantly lower when compared with all international comparisons. From a total 14,805 screen individuals, we compared 218 adolescents with pACR and 377 individuals without significant albuminuria. The Total KV adjusted to body surface (TKVBS) was significantly associated with pACR (odds ratio 1.03, 95% confidence interval 1.02-1.03). The upper quartile of TKVBS was highly associated with pACR (7.57, 4.13-13.87), hypertension (2.53, 1.66-3.86), and hyperfiltration (26 vs 11.5%). Thus, TKVBS is directly associated with pACR while greater KV, arterial hypertension, and hyperfiltration in patients with pACR suggest that the increase in volume is secondary to kidney hypertrophy. Additionally, the adaptative podocytopathy with low fibrosis seen on kidney biopsy which was performed in a subset of patients, and the smaller kidney dimensions in our population point to prenatal oligonephronia as the primary cause of the detected kidney disease.

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.

Urinary Vitamin D Binding Protein: A Marker of Kidney Tubular Dysfunction in Patients at Risk for Type 2 Diabetes

Context

Recent studies have reported elevated urinary vitamin D binding protein (uVDBP) concentrations in patients with diabetic kidney disease, although the utility of uVDBP to predict deterioration of kidney function over time has not been examined.

Objective

Our objective was to assess the association of uVDBP with longitudinal changes in kidney function.

Methods

Adults at-risk for type 2 diabetes from the Prospective Metabolism and Islet Cell Evaluation (PROMISE) study had 3 assessments over 6 years (n = 727). Urinary albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were used as measures of kidney function. Measurements of uVDBP were performed with enzyme-linked immunosorbent assay and normalized to urine creatinine (uVDBP:cr). Generalized estimating equations (GEEs) evaluated longitudinal associations of uVDBP and uVDBP:cr with measures of kidney function, adjusting for covariates.

Results

Renal uVDBP loss increased with ACR severity at baseline. Individuals with normoalbuminuria, microalbuminuria, and macroalbuminuria had median log uVDBP:cr concentrations of 1.62 μg/mmol, 2.63 μg/mmol, and 2.48 μg/mmol, respectively, and ACR positively correlated with uVDBP concentrations (r = 0.37; P < .001). There was no significant association between uVDBP and eGFR at baseline. Adjusted longitudinal GEE models indicated that each SD increase both in baseline and longitudinal uVDBP:cr was significantly associated with higher ACR over 6 years (β = 30.67 and β = 32.91, respectively). Conversely, neither baseline nor longitudinal uVDBP:cr measures showed a significant association with changes in eGFR over time. These results suggest that loss of uVDBP:cr over time may be a useful marker for predicting renal tubular damage in individuals at risk for diabetes.

Feasibility and impact of ketogenic dietary interventions in polycystic kidney disease: KETO-ADPKD-a randomized controlled trial

Ketogenic dietary interventions (KDIs) are beneficial in animal models of autosomal-dominant polycystic kidney disease (ADPKD). KETO-ADPKD, an exploratory, randomized, controlled trial, is intended to provide clinical translation of these findings (NCT04680780). Sixty-six patients were randomized to a KDI arm (ketogenic diet [KD] or water fasting [WF]) or the control group. Both interventions induce significant ketogenesis on the basis of blood and breath acetone measurements. Ninety-five percent (KD) and 85% (WF) report the diet as feasible. KD leads to significant reductions in body fat and liver volume. Additionally, KD is associated with reduced kidney volume (not reaching statistical significance). Interestingly, the KD group exhibits improved kidney function at the end of treatment, while the control and WF groups show a progressive decline, as is typical in ADPKD. Safety-relevant events are largely mild, expected (initial flu-like symptoms associated with KD), and transient. Safety assessment is complemented by nuclear magnetic resonance (NMR) lipid profile analyses.

Obesity, Hyperfiltration, and Early Kidney Damage: A New Formula for the Estimation of Creatinine Clearance

CONTEXT

Glomerular hyperfiltration may represent a direct pathogenetic link between obesity and kidney disease. The most widely used methods to estimate creatine clearance such as Cockroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) have not been validated in subjects with obesity.

OBJECTIVE

The performance of prediction formulas was compared with measured creatinine clearance (mCrCl) in subjects with obesity.

METHODS

The study population included 342 patients with obesity (mean BMI 47.6 kg/m2) without primary kidney disease. A urine collection was performed over 24 hours for measurement of CrCl.

RESULTS

mCrCl increased with body weight. The CG formula showed an overestimation at high CrCl, whereas an underestimation resulted from CKD-EPI and MDRD. To improve the accuracy of estimated CrCl (eCrCl), a new CG-based formula was developed:53+0.7×(140-Age)×Weight/(96xSCr)×(0.85iffemale)A cut-off point for BMI of 32 kg/m2 was identified, at which the new formula may be applied to improve eCrCl.

CONCLUSION

In patients with obesity the glomerular filtration rate increases with body weight, and it is associated with the presence of albuminuria, suggesting an early kidney injury. We propose a novel formula that improves the accuracy of eCrCl to avoid missed diagnoses of hyperfiltration in patients with obesity.

The association between renal hyperfiltration and mortality is not mediated by diabetes mellitus

BACKGROUND

Renal hyperfiltration (RHF), recently established as a risk factor for mortality, is linked to current and subsequent diabetes mellitus (DM). DM could be seen as a mediator in the pathway between RHF and mortality. However, the mediating role of DM in the relationship between RHF and mortality is unclear.

METHODS AND RESULTS

Based on a cohort of 2682 Finnish men from the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) followed-up for 35 years, we evaluated the association between RHF and mortality, with DM as a mediator, following two methods: a classic mediation analysis approach, using Cox regression, and a counterfactual framework for mediation analysis, using g-computation, Cox regression, and logistic regression. RHF is associated with an increased risk of mortality. This association was not mediated by DM. Under a counterfactual framework and on a hazard ratio scale, RHF association with mortality had a total effect of 1.54 (95% confidence interval, 1.26-1.98) and a controlled direct effect of 1.66 (1.34-2.16).

CONCLUSION

An association between RHF and mortality risk, independent of DM, was established. RHF should be considered, managed, and followed-up as a mortality-associated condition, regardless of the status of DM. We suggest clinicians to consider including RHF screening in routine clinical care, especially diabetic care.

Glomerular hyperfiltration is an independent predictor of postoperative outcomes: A NSQIP multi-specialty surgical cohort analysis

AIM

While high estimated glomerular filtration rate (eGFR) has been associated with increased overall mortality, its effect on postoperative outcomes is relatively understudied. We sought to investigate the association between high eGFR and 30-day postoperative outcomes using a multi-specialty surgical cohort.

METHODS

Using the National Surgical Quality Improvement Program database, we selected adult for whom eGFR could be calculated using the 2021 Chronic Kidney Disease Epidemiology Collaboration equation. Based on sex-specific distributions of eGFR stratified by age quintiles, we classified patients into low (<5th percentile), normal (5-95th percentile) and high eGFR (>95th percentile). The primary outcome was a composite of any 30-day major adverse outcomes, including: death, reoperation, cardiac arrest, myocardial infarction and stroke. Secondary outcomes included 30-day infectious complications, venous thromboembolism (VTE), bleeding requiring transfusion, prolonged length of stay and unplanned readmission. After matching for demographic differences, comorbidity burden and operative characteristics, logistic regression models were used to evaluate the association between extremes of eGFR and the outcomes of interest.

RESULTS

Of 1 668 447 patients, 84 115 (5.07%) had a high eGFR. High eGFR was not associated with major adverse outcomes (odds ratio [OR] 1.00 [95% confidence interval (CI): 0.97, 1.03]); however, it was associated with reoperation (OR 1.04 [95% CI: 1.00,1.08]), infectious complications (OR 1.14 [95% CI: 1.11, 1.16]), VTE (OR 1.15 [95% CI: 1.09, 1.22]) and prolonged length of stay (OR 1.19 [95% CI: 1.16, 1.21]).

CONCLUSION

Our findings support an association between high eGFR and adverse 30-day postoperative outcomes.

Chronic intermittent hypoxia promotes glomerular hyperfiltration and potentiates hypoxia-evoked decreases in renal perfusion and PO2

Introduction: Sleep apnea (SA) is highly prevalent in patients with chronic kidney disease and may contribute to the development and/or progression of this condition. Previous studies suggest that dysregulation of renal hemodynamics and oxygen flux may play a key role in this process. The present study sought to determine how chronic intermittent hypoxia (CIH) associated with SA affects regulation of renal artery blood flow (RBF), renal microcirculatory perfusion (RP), glomerular filtration rate (GFR), and cortical and medullary tissue PO2 as well as expression of genes that could contribute to renal injury. We hypothesized that normoxic RBF and tissue PO2 would be reduced after CIH, but that GFR would be increased relative to baseline, and that RBF, RP, and tissue PO2 would be decreased to a greater extent in CIH vs. sham during exposure to intermittent asphyxia (IA, FiO2 0.10/FiCO2 0.03). Additionally, we hypothesized that gene programs promoting oxidative stress and fibrosis would be activated by CIH in renal tissue. Methods: All physiological variables were measured at baseline (FiO2 0.21) and during exposure to 10 episodes of IA (excluding GFR). Results: GFR was higher in CIH-conditioned vs. sham (p < 0.05), whereas normoxic RBF and renal tissue PO2 were significantly lower in CIH vs. sham (p < 0.05). Reductions in RBF, RP, and renal tissue PO2 during IA occurred in both groups but to a greater extent in CIH (p < 0.05). Pro-oxidative and pro-fibrotic gene programs were activated in renal tissue from CIH but not sham. Conclusion: CIH adversely affects renal hemodynamic regulation and oxygen flux during both normoxia and IA and results in changes in renal tissue gene expression.

Association of urine phthalate metabolites levels with kidney function in 1610 US adolescents

Phthalates are widely used as plasticizer or fragrance ingredients in various consumer products worldwide. However, evidence for the overall effects of mixed exposure to phthalate on kidney function has not been widely investigated. The purpose of this article was to assess the association of urine phthalate metabolite levels and kidney injury parameters in adolescents. We used data from the combined 2007-2016 National Health and Nutrition Examination Survey (NHANES). We fitted weighted linear regressions and Bayesian kernel machine regressions (BKMR) models to explore the association of urinary phthalate metabolites with four parameters of kidney function after adjusting for covariates. Weighted linear regression models showed that MiBP (β = 8.057; P_FDR = 0.016) was significantly positively associated with eGFR and MEP (β = -0.799; P_FDR < 0.001) was significantly negatively correlated with BUN. BKMR analysis showed that the higher the concentration of phthalate metabolite mixture, the higher eGFR in adolescents. Based on the results of these two models, our findings revealed that mixed exposure to phthalates was associated with elevated eGFR in adolescents. However, as the study is cross-sectional, reverse causality is possible, and altered kidney function may impact the concentration of phthalate metabolites in urine.

The causal effects of lipid traits on kidney function in Africans: bidirectional and multivariable Mendelian-randomization study

BACKGROUND

Observational studies have investigated the effect of serum lipids on kidney function, but these findings are limited by confounding, reverse causation and have reported conflicting results. Mendelian randomization (MR) studies address this confounding problem. However, they have been conducted mostly in European ancestry individuals. We, therefore, set out to investigate the effect of lipid traits on the estimated glomerular filtration rate (eGFR) based on serum creatinine in individuals of African ancestry.

METHODS

We used the two-sample and multivariable Mendelian randomization (MVMR) approaches; in which instrument variables (IV's) for the predictor (lipid traits) were derived from summary-level data of a meta-analyzed African lipid GWAS (MALG, n = 24,215) from the African Partnership for Chronic Disease Research (APCDR) (n = 13,612) & the Africa Wits-IN-DEPTH partnership for Genomics studies (AWI-Gen) dataset (n = 10,603). The outcome IV's were computed from the eGFR summary-level data of African-ancestry individuals within the Million Veteran Program (n = 57,336). A random-effects inverse variance method was used in our primary analysis, and pleiotropy was adjusted for using robust and penalized sensitivity testing. The lipid predictors for the MVMR were high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides (TG).

FINDINGS

We found a significant causal association between genetically predicted low-density lipoprotein (LDL) cholesterol and eGFR in African ancestry individuals β = 1.1 (95% CI [0.411-1.788]; p = 0.002). Similarly, total cholesterol (TC) showed a significant causal effect on eGFR β = 1.619 (95% CI [0.412-2.826]; p = 0.009). However, the IVW estimate showed that genetically predicted HDL-C β = -0.164, (95% CI = [-1.329 to 1.00]; p = 0.782), and TG β = -0.934 (CI = [-2.815 to 0.947]; p = 0.33) were not significantly causally associated with the risk of eGFR. In the multivariable analysis inverse-variance weighted (MVIVW) method, there was evidence for a causal association between LDL and eGFR β = 1.228 (CI = [0.477-1.979]; p = 0.001). A significant causal effect of Triglycerides (TG) on eGFR in the MVIVW analysis β = -1.3 ([-2.533 to -0.067]; p = 0.039) was observed as well. All the causal estimates reported reflect a unit change in the outcome per a 1 SD increase in the exposure. HDL showed no evidence of a significant causal association with eGFR in the MVIVW method (β = -0.117 (95% CI [-1.252 to 0.018]; p = 0.840)). We found no evidence of a reverse causal impact of eGFR on serum lipids. All our sensitivity analyses indicated no strong evidence of pleiotropy or heterogeneity between our instrumental variables for both the forward and reverse MR analysis.

INTERPRETATION

In this African ancestry population, genetically predicted higher LDL-C and TC are causally associated with higher eGFR levels, which may suggest that the relationship between LDL, TC and kidney function may be U-shaped. And as such, lowering LDL_C does not necessarily improve risk of kidney disease. This may also imply the reason why LDL_C is seen to be a poorer predictor of kidney function compared to HDL. In addition, this further supports that more work is warranted to confirm the potential association between lipid traits and risk of kidney disease in individuals of African Ancestry.

FUNDING

Wellcome (220740/Z/20/Z).

Prevalence and risk factors of chronic kidney disease among patients with type 2 diabetes mellitus at a tertiary care hospital in Nepal: a cross-sectional study

OBJECTIVE

To estimate the prevalence of chronic kidney disease (CKD) among patients with type 2 diabetes mellitus (T2DM) and determine the sociodemographic and clinical risk factors associated with CKD.

DESIGN AND SETTINGS

Cross-sectional study among diabetic outpatients of a tertiary hospital in Nepal.

PARTICIPANTS

201 patients with T2DM above 18 years of age.

INTERVENTION

Participants completed a questionnaire regarding their socioeconomic information and underwent pertinent physical and haematological examinations.

PRIMARY AND SECONDARY OUTCOMES MEASURE

The prevalence and risk factors of CKD among patients with T2DM.

RESULTS

The prevalence of CKD in T2DM was 86.6%. In univariable analysis, the variables like age (p=0.026), hypertension status (p=0.002), duration of diabetes (p=0.009) and haemoglobin levels (p=0.027) were significantly associated with CKD among the participants with T2DM. Kruskal-Wallis H test showed that age was significantly different between various CKD stages. Multivariate analysis demonstrated a significant relationship between CKD with age (Adjusted odds ratio (AOR) 3, 95% CI 1.1 to 8.8) and literacy status (AOR 5.8, 95% CI 1.4 to 24.6) CONCLUSION: Advancing age, concomitant hypertension, increasing duration of T2DM and presence of anaemia were found to be important risk factors of CKD. Age is the most important predictor of CKD showing increasing prevalence in the elderly population. Periodic screening tests are essential at an early age to identify kidney diseases at incipient stages, thereby preventing progression to end-stage renal disease.

CYP1A2 Genetic Variation, Coffee Intake, and Kidney Dysfunction

IMPORTANCE

Caffeine is detoxified by cytochrome P450 1A2 (CYP1A2), and genetic variation in CYP1A2 impacts the rate of caffeine clearance. Factors that may modify the association between coffee intake and kidney disease remain unclear.

OBJECTIVE

To assess whether CYP1A2 genotype modifies the association between coffee intake and kidney dysfunction.

DESIGN, SETTING, AND PARTICIPANTS

The Hypertension and Ambulatory Recording Venetia Study (HARVEST) was a prospective cohort study of individuals with stage 1 hypertension in Italy; HARVEST began on April 1, 1990, and follow-up is ongoing. The current study used data from April 1, 1990, to June 30, 2006, with follow-up of approximately 10 years. Blood pressure and biochemical data were collected monthly during the first 3 months, then every 6 months thereafter. Data were analyzed from January 2019 to March 2019. Participants were screened and recruited from general practice clinics. The present study included 1180 untreated participants aged 18 to 45 years with stage 1 hypertension; those with nephropathy, diabetes, urinary tract infection, and cardiovascular disease were excluded.

EXPOSURES

Coffee intake and CYP1A2 genotype rs762551 were exposures analyzed over a median follow-up of 7.5 (IQR, 3.1-10.9) years.

MAIN OUTCOMES AND MEASURES

Albuminuria (defined as an albumin level of ≥30 mg/24 h) and hyperfiltration (defined as an estimated glomerular filtration rate of ≥150 mL/min/1.73 m2) were the primary outcomes as indicators of kidney dysfunction.

RESULTS

Among 1180 participants, genotyping, lifestyle questionnaires, and urine analysis data were obtained from 604 individuals (438 [72.5%] male) with a mean (SD) age of 33.3 (8.5) years and a mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 25.4 (3.4). A total of 158 participants (26.2%) consumed less than 1 cup of coffee per day, 379 (62.7%) consumed 1 to 3 cups per day, and 67 (11.1%) consumed more than 3 cups per day. Genotype frequencies for rs762551 (260 participants [43.1%] with genotype AA, 247 participants [40.8%] with genotype AC, and 97 participants [16.1%] with genotype CC) did not differ between coffee intake categories. The level of risk of developing albuminuria, hyperfiltration, and hypertension, assessed by Cox regression and survival analyses, was not associated with coffee intake in the entire group or among fast metabolizers. The risks of albuminuria (adjusted hazard ratio [aHR], 2.74; 95% CI, 1.63-4.62; P < .001), hyperfiltration (aHR, 2.11; 95% CI, 1.17-3.80; P = .01), and hypertension (aHR, 2.81; 95% CI, 1.51-5.23; P = .001) increased significantly among slow metabolizers who consumed more than 3 cups per day.

CONCLUSIONS AND RELEVANCE

In this study, the risks of albuminuria, hyperfiltration, and hypertension increased with heavy coffee intake only among those with the AC and CC genotypes of CYP1A2 at rs762551 associated with slow caffeine metabolism, suggesting that caffeine may play a role in the development of kidney disease in susceptible individuals.

Glomerular hyperfiltration: part 2-clinical significance in children

Glomerular hyperfiltration (GHF) is a phenomenon that can occur in various clinical conditions affecting the kidneys such as sickle cell disease, diabetes mellitus, autosomal dominant polycystic kidney disease, and solitary functioning kidney. Yet, the pathophysiological mechanisms vary from one disease to another and are not well understood. More so, it has been demonstrated that GHF may occur at the single-nephron in some clinical conditions while in others at the whole-kidney level. In this review, we explore the pathophysiological mechanisms of GHF in relation to various clinical conditions in the pediatric population. In addition, we discuss the role and mechanism of action of important factors such as gender, low birth weight, and race in the pathogenesis of GHF. Finally, in this current review, we further highlight the consequences of GHF in the progression of kidney disease.

Urinalysis of individuals with renal hyperfiltration using ATR-FTIR spectroscopy

Abnormal increased glomerular filtration rate (GFR), otherwise known as renal hyperfiltration (RHf), is associated with an increased risk of chronic kidney disease and cardiovascular mortality. Although it is not considered as a disease alone in medicine today, early detection of RHf is essential to reducing risk in a timely manner. However, detecting RHf is a challenge since it does not have a practical biochemical marker that can be followed or quantified. In this study, we tested the ability of ATR-FTIR spectroscopy to distinguish 17 individuals with RHf (hyperfiltraters; RHf (+)), from 20 who have normal GFR (normofiltraters; RHf(-)), using urine samples. Spectra collected from hyperfiltraters were significantly different from the control group at positions 1621, 1390, 1346, 933 and 783/cm. Intensity changes at these positions could be followed directly from the absorbance spectra without the need for pre-processing. They were tentatively attributed to urea, citrate, creatinine, phosphate groups, and uric acid, respectively. Using principal component analysis (PCA), major peaks of the second derivative forms for the classification of two groups were determined. Peaks at 1540, 1492, 1390, 1200, 1000 and 840/cm were significantly different between the two groups. Statistical analysis showed that the spectra of normofiltraters are similar; however, those of hyperfiltraters show diversity at multiple positions that can be observed both from the absorbance spectra and the second derivative profiles. This observation implies that RHf can simultaneously affect the excretion of many substances, and that a spectroscopic analysis of urine can be used as a rapid and non-invasive pre-screening tool.

Serum Cystatin C Levels Could Predict Rapid Kidney Function Decline in A Community-Based Population

BACKGROUND

Several biomarkers have been correlated with the prevalence and severity of chronic kidney disease (CKD); however, the association between biomarkers and rapid kidney function decline (RKFD) is unknown. This study aimed to evaluate the predictive performance of biomarkers to determine who is likely to develop RKFD in a healthy population.

METHODS

A community-based cohort of 2608 people residing in northern Taiwan were enrolled, and their renal function was followed annually from January 2014 to December 2019. The outcomes of interest were RKFD, defined as a 15% decrease in the estimated glomerular filtration rate (eGFR) within the first 4 years, and a decrease in eGFR without improvement in the fifth year. Clinical variables and potential predictors of RKFD, namely adiponectin, leptin, tumor necrosis factor-alpha, and cystatin C, were measured and analyzed.

RESULTS

The incidence of RKFD was 17.0% (105/619). After matching for age and sex at a 1:1 ratio, a total of 200 subjects were included for analysis. The levels of cystatin C and total vitamin D were significantly negatively correlated with eGFR. eGFR was negatively correlated with the levels of cystatin C and total vitamin D. Among the biomarkers, cystatin C showed the best predictive performance for RKFD (area under the receiver operating characteristic curve: 0.789). Lower serum cystatin C was associated with a higher rate of RKFD in healthy subjects. A generalized additive model showed that 0.82 mg/L was an adequate cut-off value of cystatin C to predict RKFD. Multivariable logistic regression analysis further indicated that low cystatin C and eGFR were independent predictors of the possibility of RKFD.

CONCLUSIONS

Serum cystatin C level could predict the possibility of RKFD. We suggest that a low cystatin C level should be considered as a risk factor for RKFD in healthy subjects.

Association of Estimated Glomerular Filtration Rate with Risk of Head and Neck Cancer: A Nationwide Population-Based Study

In this study, through a cohort study of 10 million people, we investigated the association between estimated glomerular filtration rate (eGFR) and head and neck cancer (HNC) incidence. This is an observational cohort study using data from the national health claims database established by the Korean National Health Insurance Service (NHIS). We selected 9,598,085 participants older than 20 years who had undergone health checkups in 2009. A health checkup involves the history of any diseases, current health status, and results of several physical and blood exams including eGFR. We investigated the presence of HNC diagnosis in their national health insurance data from 2010 to 2018. Of the 9,598,085 participants, 10,732 had been newly diagnosed with HNC in the 9-year follow-up. In the multivariate Cox proportional hazard model, participants with elevated eGFR were associated with a risk of HNC incidence (HR = 1.129; 95% CI = 1.075−1.186 for eGFR = 90−104 mL/min/1.73 m2 and HR = 1.129; 95% CI = 1.076−1.194 for eGFR ≥ 105 mL/min/1.73 m2) compared with those with eGFR 60−89 mL/min/1.73 m2. Among HNC, the incidences of oral cavity, oropharyngeal, hypopharyngeal, and laryngeal cancers were significantly increased in the elevated eGFR group. According to the subgroup analysis, participants with eGFR ≥ 60 mL/min/1.73 m2 were correlated with risk of HNC incidence in middle age, non/mild drinker, low BMI, no diabetes, and no hypertension patients compared with those with eGFR < 60 mL/min/1.73 m2. Elevated eGFR was associated with the risk of some type of HNC, even in individuals with adjusted hypertension and diabetes without chronic diseases. The results of this study have implications for etiological investigations and preventive strategies.

Changes in residual kidney Pulsatility Index following living donor nephrectomy

OBJECTIVE

Nephrectomy in kidney transplant donors provokes a compensatory hyperfiltration process of the residual kidney, characterized by changes in renal vascular hemodynamics. This research aimed to determine the short-term difference in the pulsatility index (PI) of kidney transplant donors' residual kidney before and after nephrectomy.

METHODS

This is a prospective historical study using secondary data from kidney transplant living donors who have undergone nephrectomy at a tertiary referral hospital in Jakarta, Indonesia, from March 2019 to January 2020. PI of renal, segmental, interlobar, and arcuate arteries of the residual kidneys were measured in the preoperative and day-1, day-7, day-30 postoperative period. The pre- and postoperative PI values were statistically analyzed to examine differences between the groups.

RESULTS

PI of 40 residual kidneys were obtained. There were no significant mean PI changes in the arteries except for the middle interlobar artery (p = 0.049), which showed no significant difference after post hoc analysis.

CONCLUSIONS

There is no significant short-term difference in PI of the residual kidney before and after kidney transplant donor nephrectomy.

ADVANCES IN KNOWLEDGE

Short-term postoperative PI of the residual kidney arteries may not be suitable as a predictor for chronic kidney disease in kidney transplant donors. Other quantitative Doppler ultrasound parameters must be considered.

SLC12A3 Variation and Renal Function in Chinese Patients With Hypertension

Objective

SLC12A3 (solute carrier family 12 member 3) gene variants are associated with diabetic nephropathy; however, their association with hypertensive nephropathy remains unknown. We aimed to investigate the association between SLC12A3 gene polymorphisms and renal function in patients with hypertension.

Methods

Participants from three non-diabetic hypertensive cohorts, including young-onset hypertension (cohort 1, n = 882), treatment-naïve hypertension (cohort 2, n = 90), and follow-up cohort (cohort 3, n = 166), underwent genotyping for single nucleotide polymorphisms in SLC12A3. Renal events were defined as a >25 and >50% decline in estimated glomerular filtration rate (eGFR).

Results

In cohort 1, SLC12A3 rs16963397 C/C or C/G (P = 0.005), rs13334864 C/C or C/T (P = 0.020), and rs7187932 A/A or A/G polymorphisms (P = 0.014) had higher eGFRs compared to their counterparts, with similar findings observed in cohort 2. In cohort 3, over a mean follow-up of 5.8 ± 1.7 years, participants with either SLC12A3 rs16963397 C/C or rs13334864 C/C polymorphisms had more >25 and >50% eGFR decline than their counterparts (log-rank test, P = 0.058 and P = 0.038, respectively). Cox regression analysis revealed that SLC12A3 rs16963397 C/C and rs13334864 C/C polymorphisms were significantly associated with an increased risk of >25% [hazard ratio (HR), 3.294; 95% confidence interval (CI), 1.158–9.368; P = 0.025] and >50% decline in eGFR (HR, 18.630; 95% CI, 1.529–227.005, P = 0.022) than their counterparts.

Conclusion

SLC12A3 polymorphisms are associated with renal function in Chinese patients with hypertension.

ASSESSING PREDICTORS OF DIRECTLY ACTING ANTIVIRALS' FAILURE AS A FURTHER STEP TOWARDS MORE EFFICIENT HCV ELIMINATION PROGRAMS: IL28B (IFNL4) GENE POLYMORPHISM HAS NO ROLE WHILE HIGHER ESTIMATED CREATININE CLEARANCE IS A FORGOTTEN FACTOR

BACKGROUND

Sustained virologic response (SVR) rates after directly acting antivirals (DAAs) for hepatitis C virus (HCV) exceed 95%. This encouraged policymakers to put plans to achieve HCV elimination by 2030. The remaining percentage of non-SVR12 can affect HCV eradication strategies in the real-world especially the compliance of large numbers of treated persons to follow up for assessment of virologic response cannot be guaranteed.

OBJECTIVE

We aimed to assess predictors of failure to achieve SVR after receiving sofosbuvir plus NS5A inhibitor as an important step towards achieving better HCV eradication strategies.

METHODS

During the period from 1st November 2018 to 1st November 2019, 1581 treatment-naive patients received sofosbuvir plus daclatasvir ± ribavirin at our unit and 10 patients were referred to us with HCV relapse after the same regimens. A total of 163 out of the 1581 patients were lost for follow-up before assessment of virologic response and excluded from the analysis. 20 out of the remaining patients failed to achieve SVR12. Data from the 30 patients with non-SVR12 were included in the case-control analysis.

RESULTS

Every unit increase in estimated creatinine clearance using modification of diet in renal disease study (MDRD) score, total bilirubin, and INR was associated with 1.03, 13.92, and 80.08 times greater odds of non-SVR12 (P<0.001, P=0.0016, P=0.02) respectively. The presence of liver cirrhosis on ultrasonography increases the odds by 10.03. (P=0.009).

CONCLUSION

Higher MDRD score, INR, total bilirubin, and presence of sonographic features of liver cirrhosis are predictors of failure to achieve SVR12 using sofosbuvir plus NS5A inhibitor.

The association between skinfold thicknesses and estimated glomerular filtration rate in adolescents: a cross-sectional study

Background

Obesity is one of the causes of glomerular hyperfiltration. Studies on the relationship between body fat content and glomerular hyperfiltration have been limited to special children. Therefore, we aimed to evaluate the correlation between skinfold thickness, which represents body fat content, and estimated glomerular filtration rate (eGFR).

Methods

The cross-sectional study included 6655 participants (3532 boys and 3123 girls; age: 12 − 17.99 years); data was obtained from the National Health and Nutrition Examination Survey (NHANES; 2001–2010). The independent variables were subscapular skinfold thickness and triceps skinfold thickness. The dependent variable was eGFR. We used multivariate linear regression models to evaluate their associations and also performed subgroup analyses.

Results

After adjusting for age, standing height, race, family income, blood urea nitrogen and uric acid variables, multivariate regression analysis identified that triceps skinfold thickness and subscapular skinfold thickness were positively correlated with eGFR and glomerular hyperfiltration in boys. In subgroup analyses stratified by age and body mass index, triceps skinfold thickness was also associated with glomerular hyperfiltration in boys. There was a linear relationship between triceps skinfold thickness and eGFR in boys (β = 0.389, P < 0.001) and girls (β = 0.159, P = 0.0003).

Conclusions

Triceps skinfold thickness and subscapular skinfold thickness are positively correlated with eGFR and glomerular hyperfiltration in US male adolescents. In all adolescents, there is a linear relationship between triceps skinfold thickness and eGFR.

Combining Neprilysin Inhibitor With AT2R Agonist Is Superior to Combination With AT1R Blocker in Providing Reno-Protection in Obese Rats

Clinical use of the combination therapy of the neprilysin inhibitor sacubitril and angiotensin II type 1 receptor blocker valsartan is known to be associated with albuminuria. Albuminuria is both a risk factor for and an indicator of kidney injury. Earlier work from our laboratory reported that the agonist of angiotensin II type 2 receptor Compound 21 (C21) prevents proteinuria, albuminuria, and is reno-protective in obese Zucker rats fed high salt diet (HSD). Thus, we hypothesized that sacubitril/C21 combination provides superior reno-protection compared to sacubitril/valsartan. Male obese Zucker rats 10–11 weeks old were treated daily with vehicle, sacubitril + C21, or sacubitril + valsartan while fed HSD for 16 days. HSD-feeding caused kidney dysfunction, evident by significant increases in urinary protein, osteopontin, and cystatin C. HSD-feeding lowered plasma cystatin C and creatinine concentrations suggestive of hyperfiltration, which was not affected by either treatment. Unlike sacubitril/valsartan, sacubitril/C21 treatment significantly decreases proteinuria, albuminuria, the expression of nephrin, and kidney weight, independent of hyperfiltration, compared with HSD alone. Moreover, sacubitril/valsartan therapy increased plasma renin and did not prevent HSD-induced increases in renal angiotensin II, while sacubitril/C21 completely prevented these changes. Together, this study suggests that sacubitril/C21 afforded superior reno-protection compared to sacubitril/valsartan therapy in high salt-fed obese Zucker rats.

Smoking tobacco is associated with renal hyperfiltration

Tobacco consumption is a renal risk factor, but the effects on the estimated glomerular filtration rate (eGFR) remain unclear. We aimed to evaluate the possible impact of using tobacco products (smoking and snus) on eGFR based on creatinine or cystatin C. We used a first cohort with 949 participants and a second cohort with 995 participants; none had pre-existing renal disease. All subjects donated a blood sample and completed a questionnaire, including questions about tobacco use. To assess the effect on eGFR, hierarchical multiple linear regression models were used. Active smoking associated independently with a higher eGFRcreatinine in all subjects (p < 0.001; β = 0.11). Further analyses stratified for sex, showed similar findings for men (p < 0.001; β = 0.14) and for women (p = 0.026; β = 0.10). eGFRcystatin C was significantly associated with active smoking in all subjects (p = 0.040; β = -0.05), but no association was seen after stratification for sex. Snus did not associate with eGFR. In conclusion, smoking associated significantly with a higher eGFRcreatinine. The mechanism may be renal hyperfiltration of smaller molecules such as creatinine. This is probably caused by substances from smoked tobacco other than nicotine, as no effect was seen for snus.

Kidney disease risk factors do not explain impacts of low dietary protein on kidney function and structure

The kidneys balance many byproducts of the metabolism of dietary components. Previous studies examining dietary effects on kidney health are generally of short duration and manipulate a single macronutrient. Here, kidney function and structure were examined in C57BL/6J mice randomized to consume one of a spectrum of macronutrient combinations (protein [5%–60%], carbohydrate [20%–75%], and fat [20%–75%]) from weaning to late-middle age (15 months). Individual and interactive impacts of macronutrients on kidney health were modeled. Dietary protein had the greatest influence on kidney function, where chronic low protein intake decreased glomerular filtration rates and kidney mass, whereas it increased kidney immune infiltration and structural injury. Kidney outcomes did not align with cardiometabolic risk factors including glucose intolerance, overweight/obesity, dyslipidemia, and hypertension in mice with chronic low protein consumption. This study highlights that protein intake over a lifespan is an important determinant of kidney function independent of cardiometabolic changes.

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Chronic high macronutrient intake from any source increases kidney function (GFR)

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Low protein intake led to greater kidney tubular structural injury and inflammation

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Lower protein intake decreased kidney mass and glomerular filtration capacity

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Kidney outcomes did not align with longevity or cardiometabolic outcomes

TDAG51 induces renal interstitial fibrosis through modulation of TGF-β receptor 1 in chronic kidney disease

Chronic kidney disease (CKD) is characterized by the gradual loss of renal function and is a major public health concern. Risk factors for CKD include hypertension and proteinuria, both of which are associated with endoplasmic reticulum (ER) stress. ER stress-induced TDAG51 protein expression is increased at an early time point in mice with CKD. Based on these findings, wild-type and TDAG51 knock-out (TDKO) mice were used in an angiotensin II/deoxycorticosterone acetate/salt model of CKD. Both wild-type and TDKO mice developed hypertension, increased proteinuria and albuminuria, glomerular injury, and tubular damage. However, TDKO mice were protected from apoptosis and renal interstitial fibrosis. Human proximal tubular cells were used to demonstrate that TDAG51 expression induces apoptosis through a CHOP-dependent mechanism. Further, a mouse model of intrinsic acute kidney injury demonstrated that CHOP is required for ER stress-mediated apoptosis. Renal fibroblasts were used to demonstrate that TGF-β induces collagen production through an IRE1-dependent mechanism; cells treated with a TGF-β receptor 1 inhibitor prevented XBP1 splicing, a downstream consequence of IRE1 activation. Interestingly, TDKO mice express significantly less TGF-β receptor 1, thus, preventing TGF-β-mediated XBP1 splicing. In conclusion, TDAG51 induces apoptosis in the kidney through a CHOP-dependent mechanism, while contributing to renal interstitial fibrosis through a TGF-β-IRE1-XBP1 pathway.

Early life factors in relation to albuminuria and estimated glomerular filtration rate based on cystatin C and creatinine in adults from a Swedish population-based cohort study

Background

Early life factors influence the number of nephrons a person starts life with and a consequence of that is believed to be premature kidney ageing. Thus, we aimed to identify early life factors associated with cystatin C and creatinine-based estimated glomerular filtration (eGFR) rate equations and urine -albumin-to-creatinine ratio after a follow-up of 46–67 years.

Methods

The study included 593 Swedish subjects without diabetes mellitus from the Malmo Diet Cancer Cohort. Perinatal data records including birth weight, gestational age, placenta weight and maternal related risk factors were analysed. eGFR was determined by Chronic Kidney Disease Epidemiology (CKD-EPI), the Lund-Malmö revised and Caucasian, Asian, Paediatric, and Adult (CAPA) equations. Postnatal growth phenotypes were defined as low (≤ 0) or high (> 0) birth weight z-score, or low (≤ median) or high (> median) body mass index at 20 years of age.

Results

In women, lower birth weight was associated with lower eGFR (CAPA; CKD-EPI cystatin C). Birth weight z-score predicted adult albuminuria specifically in men (OR 0.75, 95% CI [0.58; 0.96]). Women with high birth weight z-score and low BMI at 20 years had lower eGFR (CAPA; CKD-EPI cystatin C; p = 0.04). Men with high birth weight z-score and high BMI at 20 years had lower risk for albuminuria (OR 0.35, 95% CI [0.12; 0.93]).

Conclusions

Lower birth weight, prematurity and postnatal growth curve have a potential sex- specific effect of early exposure to an adverse environment on lower cystatin C-based eGFR and albuminuria later in life. Cystatin C compared to creatinine -eGFR equations shows a higher ability to detect these findings.

Graphic abstract

Characterising the relationships between physiological indicators and all-cause mortality (NHANES): a population-based cohort study

BACKGROUND

Mortality risk stratification based on dichotomising a physiological indicator with a cutoff point might not adequately capture increased mortality risk and might not account for non-linear associations. We aimed to characterise the linear and non-linear relationships of 27 physiological indicators with all-cause mortality to evaluate whether the current clinical thresholds are suitable in distinguishing patients at high risk for mortality from those at low risk.

METHODS

For this observational cohort study of the US non-institutionalised population, we used data from adults (≥18 years) included in the 1999-2014 National Health and Nutrition Examination Survey (NHANES) linked with National Death Index mortality data collected from Jan 1, 1999, up until Dec 31, 2015. We used Cox proportional hazards regression models adjusted for age, sex, and race or ethnicity to assess associations of physiological indicators with all-cause mortality. We assessed non-linear associations by discretising the physiological indicator into nine quantiles (termed novemtiles) and by using a weighted sum of cubic polynomials (spline). We used ten-fold cross validation to select the most appropriate model using the concordance index, Nagelkerke R2, and Akaike Information Criterion. We identified the level of each physiological indicator that led to a 10% increase in mortality risk to define our cutoffs used to compare with the current clinical thresholds.

FINDINGS

We included 47 266 adults of 82 091 assessed for eligibility. 25 (93%) of 27 indicators showed non-linear associations with substantial increases compared with linear models in mortality risk (1·5-2·5-times increase). Height and 60 s pulse were the only physiological indicators to show linear associations. For example, participants with an estimated glomerular filtration rate (GFR) of less than 65 mL/min per 1·73 m2 or between 90-116 mL/min per 1·73 m2 are at moderate (hazard ratio 1-2) mortality risk. Those with a GFR greater than 117 mL/min per 1·73 m2 show substantial (hazard ratio ≥2) mortality risk. Both lower and higher values of cholesterol are associated with increased mortality risk. The current clinical thresholds do not align with our mortality-based cutoffs for fat deposition indices, 60 s pulse, triglycerides, cholesterol-related indicators, alkaline phosphatase, glycohaemoglobin, homoeostatic model assessment of insulin resistance, and GFR. For these indicators, the misalignment suggests the need to consider an additional bound when only one is provided.

INTERPRETATION

Most clinical indicators were shown to have non-linear associations with all-cause mortality. Furthermore, considering these non-linear associations can help derive reliable cutoffs to complement risk stratification and help inform clinical care delivery. Given the poor alignment with our proposed cutoffs, the current clinical thresholds might not adequately capture mortality risk.

Life course pathways from parental education to age-related decrements in kidney function among Black and white American adults

OBJECTIVE

Using cross-sectional data on Black and white adults, this analysis examined whether age-related decrements in kidney function across adulthood were associated with parental education, and whether the association was differentially influenced by race. Further, this study assessed racial differences in life course pathways from parental education to age-related decrements in kidney function, through current SES and health-related risk factors.

METHOD

Data from the main survey and the Biomarker Project of the Midlife in the United States (MIDUS) Wave 2 and Refresher samples were combined, resulting in 1861 adults (54.5% female; age 25-84, M_age = 53.37) who self-identified as non-Hispanic Black (n = 326) and non-Hispanic white (n = 1535). Estimated glomerular filtration rate (eGFR) was based on serum creatinine, calculated using the CKD-EPI formula. Adults SES was based on education, income, and financial strains. Health-related risk factors included obesity, elevated blood pressure (BP), and insulin resistance. Hypotheses were tested by utilizing multiple linear regression and regression-based moderated mediation analysis.

RESULTS

Lower parental education was associated with steeper age-related decrements in eGFR (B = 0.38, SE = 0.15, p = .013, 95%CI = 0.08, 0.68), due to higher eGFR among younger participants and lower eGFR among older participants. In addition, age-related decrements in kidney function were steeper among Black relative to white adults (B = 0.41, SE = 0.13, p < .01, 95%CI = 0.16, 0.66), driven by higher proportion of younger Black adults that met criterion for renal hyperfiltration. Furthermore, parental education and race were associated with age-related decrements in kidney function in an additive rather than interactive way. There were some racial differences in the life course pathways from parental education to age-related differences in eGFR, glucoregulation, and hypertension. Among Black adults, lower parental education was associated with elevated eGFR among younger participants through insulin resistance. Among white adults, lower parental education was linked to higher eGFR among younger adults and lower eGFR among older adults, and the association was mediated by current SES, elevated BP, and insulin resistance.

DISCUSSION

Early life SES can have a long-lasting influence on the preclinical renal senescence that is associated with the normal biology of aging for both Black and white adults.

Blocking angiotensin 2 receptor attenuates diabetic nephropathy via mitigating ANGPTL2/TL4/NF-κB expression

BACKGROUND

Diabetic nephropathy (DN) is a consequence of diabetes mellitus (DM) and is associated with early changes in renal angiotensin II (ANG II). These changes were evaluated using ANG II blocker valsartan early from week two of diabetes (experiment I, renoprotective) and late from week nine of diabetes (experiment II, renotherapeutic) to the end of both experiments at week twelve.

METHODS AND RESULTS

In both experiments, adult male Wister rats were divided into (i) vehicle group; (ii) valsartan received oral 30 mg/Kg/day; (iii) diabetic received single 50 mg/Kg intraperitoneal streptozotocin injection; (iv) renoprotection, diabetic rats received valsartan treated in experiments I and II. DM effects on urine albumin excretion, blood pressure, and renal ANG II were measured. Urinary nephrin, kidney injury molecule-1 (KIM-1), renal angiopoietin-like protein 2 (ANGPTL2), and toll-like receptor 4 (TLR 4) mRNA expression were tested. DM-initiated fibrotic markers integrin, α-smooth muscle actin expression, and collagen IV and apoptotic protein caspase 3 were tested. DM induced early changes starting from week four in the tested variables. At week twelve, in both experiments, valsartan intervention showed a significant reduction in ANG II, ANGPTL2, TLR 4 and integrin expression and improvement in albuminuria, blood pressure, urinary biomarkers, fibrotic and apoptotic markers.

CONCLUSIONS

Changes leading to DN starts early in the disease course and ANG II reduction decreased the expression of ANGPTL2 and integrin which preserve the glomerular barrier. Blocking ANG II was able to decrease TLR 4 and inflammatory cytokines leading to decreasing DN.

Fibrosis, the Bad Actor in Cardiorenal Syndromes: Mechanisms Involved

Cardiorenal syndrome is a term that defines the complex bidirectional nature of the interaction between cardiac and renal disease. It is well established that patients with kidney disease have higher incidence of cardiovascular comorbidities and that renal dysfunction is a significant threat to the prognosis of patients with cardiac disease. Fibrosis is a common characteristic of organ injury progression that has been proposed not only as a marker but also as an important driver of the pathophysiology of cardiorenal syndromes. Due to the relevance of fibrosis, its study might give insight into the mechanisms and targets that could potentially be modulated to prevent fibrosis development. The aim of this review was to summarize some of the pathophysiological pathways involved in the fibrotic damage seen in cardiorenal syndromes, such as inflammation, oxidative stress and endoplasmic reticulum stress, which are known to be triggers and mediators of fibrosis.

The effects of beraprost sodium on renal function and cardiometabolic profile in patients with diabetes mellitus: a systematic review and meta-analysis of clinical trials

PURPOSE

This systematic review and meta-analysis aimed to assess renal function and cardiometabolic biomarkers after treatment with beraprost sodium in patients with diabetes mellitus.

METHODS

We systemically searched PubMed, Embase, Scopus, Web of Science, and Cochrane Library up to August 2020. Statistical heterogeneities were computed using Cochrane's Q test and I² test. A fixed- or random-effects model was used to calculate the weighted mean difference (WMD) and corresponding 95% confidence intervals (CI).

RESULTS

From 341citations, seven trials were included into our meta-analysis. Our findings demonstrated that beraprost sodium intake significantly decreased blood urea nitrogen (BUN) (WMD = -5.62, 95% CI [-8.49, -2.74], P < 0.001) and cystatin C (WMD = -0.57, 95% CI [-0.68, -0.46], P < 0.001). Beraprost sodium intake had no significant effect on fasting blood sugar (FBS), hemoglobin A1c (HbA1c), cholesterol (TC), triglycerides (TG), HDL-C, LDL-C, systolic blood pressure (SBP), diastolic blood pressure (DBP), and creatinine (Cr) in patients with diabetes receiving beraprost sodium in comparison with the controls.

CONCLUSION

Our meta-analysis revealed that beraprost sodium administration significantly decreased BUN and cystatin C levels in patients with diabetes. However, no significant effect was observed on the cardiometabolic profile.

Advanced glycation end products as predictors of renal function in youth with type 1 diabetes

To examine if skin autofluorescence (sAF) differed in early adulthood between individuals with type 1 diabetes and age-matched controls and to ascertain if sAF aligned with risk for kidney disease. Young adults with type 1 diabetes (N = 100; 20.0 ± 2.8 years; M:F 54:46; FBG-11.6 ± 4.9 mmol/mol; diabetes duration 10.7 ± 5.2 years; BMI 24.5(5.3) kg/m²) and healthy controls (N = 299; 20.3 ± 1.8 years; M:F-83:116; FBG 5.2 ± 0.8 mmol/L; BMI 22.5(3.3) kg/m²) were recruited. Skin autofluorescence (sAF) and circulating AGEs were measured. In a subset of both groups, kidney function was estimated by GFR_{CKD-EPI CysC} and uACR, and DKD risk defined by uACR tertiles. Youth with type 1 diabetes had higher sAF and BMI, and were taller than controls. For sAF, 13.6% of variance was explained by diabetes duration, height and BMI (P_model = 1.5 × 10^-12). In the sub-set examining kidney function, eGFR and sAF were higher in type 1 diabetes versus controls. eGFR and sAF predicted 24.5% of variance in DKD risk (P_model = 2.2 × 10^-9), which increased with diabetes duration (51%; P_model < 2.2 × 10^-16) and random blood glucose concentrations (56%; P_model < 2.2 × 10^-16). HbA_1C and circulating fructosamine albumin were higher in individuals with type 1 diabetes at high versus low DKD risk. eGFR was independently associated with DKD risk in all models. Higher eGFR and longer diabetes duration are associated with DKD risk in youth with type 1 diabetes. sAF, circulating AGEs, and urinary AGEs were not independent predictors of DKD risk. Changes in eGFR should be monitored early, in addition to uACR, for determining DKD risk in type 1 diabetes.

Evaluation of renal injury in children with a solitary functioning kidney

Objective

Children with a solitary functioning kidney have an increased risk of developing renal injury that is hypothesized to be caused by glomerular hyperfiltration. In this study, we aimed to assess the early signs of renal injury and ambulatory blood pressure profiles in children with a solitary functioning kidney.

Materials and Methods

Data of children with normal office blood pressure measurement and a solitary functioning kidney were reviewed (serum creatinine and urine albumin and β2 microglobulin excretions), and 23 age-, weight-, and height-matched healthy children were considered as a control group. The size of the kidney was measured by renal ultrasound, and the presence of compensatory hypertrophy was calculated for all the subjects. Also, the subjects were additionally assessed for blood pressure (BP) pattern and the presence of hypertension by 24-hambulatory blood pressure monitoring.

Results

The solitary functioning kidney demonstrated compensatory hypertrophy in 36 out of the patients (86%) at a mean age of 14.0 (SD 3.0) years. Increased urine albumin and β2 microglobulinuria, which are signs of kidney damage, were found in 7 (17%) and 5(12%) patients. Compared with the controls, patients had significantly higher mean blood pressure standard deviation scores (p>0,001), and ambulatory blood pressure monitoring identified masked hypertension in 7 (17%) children and prehypertension in 6 (14%) patients. Therefore, renal injury, defined as the presence of hypertension and/or albuminuria and/or β2 microglobulinuria and/or hypertension, was present in 36% of all children with a solitary functioning kidney.

Conclusion

Children with a solitary functioning kidney need prolonged follow-up to detect early signs of renal injury and prevent end-organ damage later in life. Ambulatory blood pressure monitoring is an essential tool in the diagnosis and clinical management of solitary functioning kidney patients.

Arterial stiffness in regards to kidney function in middle-aged subjects with metabolic syndrome: Lithuanian high-risk cohort

OBJECTIVE

The current study aimed to check whether early vascular aging, measured as carotid-femoral pulse wave velocity (cfPWV), is related to kidney function, measured as creatinine-based estimated glomerular filtration (eGFR) and urinary albumin-to-creatinine ratio (UACR), in middle-aged subjects with metabolic syndrome.

METHODS

Participants were recruited from Lithuanian high-risk cohort (LitHiR). The cohort consists of middle-aged individuals with high cardiovascular risk but without overt cardiovascular disease. Participants underwent baseline and second visit hemodynamics measurement, including aortic mean arterial pressure (MAP), cfPWV, crPWV, carotid-intima media thickness measurement (CIMT) and biochemical analysis and all fulfilled NCEP/ATPIII criteria for metabolic syndrome diagnosis. First of all, we had determined correlations among hemodynamic measurement and eGFR together with albuminuria, expressed as UACR. Then we compared subjects who experienced significant eGFR decline with the remaining population and determining factors influencing this.

RESULTS

A total of 689 subject data were eligible for analysis. We observed relationship between cfPWV and MAP, crPWV, glucose, BMI, C-reactive protein, waist circumference except kidney function measured as eGFR at the baseline and at the second visit. eGFR was not associated with MAP or albuminuria. Baseline but not second visit UACR significantly positively correlated with cfPWV (r-spearman = 0.146, P = 0.003) and MAP (r-spearman = 0.142, P = 0.005). eGFR decline was mainly observed in subjects with higher baseline eGFR and was independently influenced by increase in cfPWV.

CONCLUSION

In middle-aged subjects with prevalent metabolic syndrome eGFR decline is related to aortic and not peripheral arterial stiffening. Better baseline kidney function could be possibly an effect of glomerular hyperfiltration, and it allows us to conclude that this phenomenon indicates early vascular damage and it should be addressed seriously in metabolic syndrome patients with normal kidney function.

Peri-renal adipose inflammation contributes to renal dysfunction in a non-obese prediabetic rat model: Role of anti-diabetic drugs

Diabetic nephropathy is a major health challenge with considerable economic burden and significant impact on patients' quality of life. Despite recent advances in diabetic patient care, current clinical practice guidelines fall short of halting the progression of diabetic nephropathy to end-stage renal disease. Moreover, prior literature reported manifestations of renal dysfunction in early stages of metabolic impairment prior to the development of hyperglycemia indicating the involvement of alternative pathological mechanisms apart from those typically triggered by high blood glucose. Here, we extend our prior research work implicating localized inflammation in specific adipose depots in initiating cardiovascular dysfunction in early stages of metabolic impairment. Non-obese prediabetic rats showed elevated glomerular filtration rates and mild proteinuria in absence of hyperglycemia, hypertension, and signs of systemic inflammation. Isolated perfused kidneys from these rats showed impaired renovascular endothelial feedback in response to vasopressors and increased flow. While endothelium dependent dilation remained functional, renovascular relaxation in prediabetic rats was not mediated by nitric oxide and prostaglandins as in control tissues, but rather an upregulation of the function of epoxy eicosatrienoic acids was observed. This was coupled with signs of peri-renal adipose tissue (PRAT) inflammation and renal structural damage. A two-week treatment with non-hypoglycemic doses of metformin or pioglitazone, shown previously to ameliorate adipose inflammation, not only reversed PRAT inflammation in prediabetic rats, but also reversed the observed functional, renovascular, and structural renal abnormalities. The present results suggest that peri-renal adipose inflammation triggers renal dysfunction early in the course of metabolic disease.

Performance and Determinants of Serum Creatinine and Cystatin C-Based GFR Estimating Equations in South Asians

INTRODUCTION

The creatinine-based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate (eGFR) equation was calibrated for the general Pakistan population (eGFRcr-PK) to eliminate bias and improve accuracy. Cystatin C-based CKD-EPI equations (eGFRcys and eGFRcr-cys) have not been assessed in this population, and non-GFR determinants of cystatin C are unknown.

METHODS

We assessed eGFRcys, eGFRcr-cys, and non-GFR determinants of cystatin C in a cross-sectional study of 557 participants (≥40 years of age) from Pakistan. We compared bias (median difference in measured GFR [mGFR] and eGFR), precision (interquartile range [IQR] of differences), accuracy (percentage of eGFR within 30% of mGFR), root mean square error (RMSE), and classification of mGFR <60 ml/min/1.73 m2 (area under the receiver operating characteristic curve [AUC] and net reclassification index [NRI]) among eGFR equations.

RESULTS

We found that eGFRcys underestimated mGFR (bias, 12.7 ml/min/1.73 m2 [95% confidence interval {CI} 10.7-15.2]). eGFRcr-cys did not improve performance over eGFRcr-PK in precision (P = 0.52), accuracy (P = 0.58), or RMSE (P = 0.49). Results were consistent among subgroups by age, sex, smoking, body mass index (BMI), and eGFR. NRI was 7.31% (95% CI 1.52%-13.1%; P < 0.001) for eGFRcr-cys versus eGFRcr-PK, but AUC was not improved (0.92 [95% CI 0.87-0.96] vs. 0.90 [95% CI 0.86-0.95]; P = 0.056). Non-GFR determinants of higher cystatin C included male sex, smoking, higher BMI and total body fat, and lower lean body mass.

CONCLUSION

eGFRcys underestimated mGFR in South Asians and eGFRcr-cys did not offer substantial advantage compared with eGFRcr-PK. Future studies are warranted to better understand the large bias in eGFRcys and non-GFR determinants of cystatin C in South Asians.

The HARVEST. Looking for optimal management of young people with stage 1 hypertension

In the last few decades there has been much debate about the management of low-risk stage 1 hypertension in youth. In this article, we review the main findings of the HARVEST cohort accrued over 30 years, highlighting the contribution of this study to the existing literature. Tachycardia and sympathetic overdrive were closely intertwined in our HARVEST participants, promoting the development of sustained hypertension, metabolic abnormalities, and increased susceptibility to vascular complications. Short-term blood pressure variability in this age group had a prognostic power even greater than that of average 24h blood pressure. In the HARVEST participants, changes in left ventricular anatomy and contractility were the earliest signs of hypertensive cardiac involvement, whereas left ventricular filling was only marginally affected. Our results highlighted the role of glomerular hyperfiltration in determining microalbuminuria and renal damage in the early stage of hypertension. The genetic approach provided an important contribution to risk stratification and patient management. The HARVEST confirmed the importance of maintaining a good lifestyle for preventing the onset of hypertension, diabetes and cardiovascular events. Isolated systolic hypertension in the first decades of life appeared as a heterogeneous condition. To establish whether antihypertensive drug treatment should be started in this condition the clinician should consider the individual cardiovascular risk profile, the level of office mean BP and central BP. Despite recent progress in our knowledge, systolic hypertension still represents a challenging issue for the clinician. Hopefully, the HARVEST will continue to contribute data that help to fill the present gaps in evidence.

Energy Expenditure Improved Risk Factors Associated with Renal Function Loss in NAFLD and MetS Patients

To assess the efficacy of three lifestyle interventions on the reduction of liver fat content and metabolic syndrome (MetS), and whether such reductions would influence renal outcomes, we conducted a randomized controlled trial on 128 participants with MetS and non-alcoholic fatty liver disease (NAFLD), as well as available data on estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatine ratio (UACR). Patients were randomized in 1:1:1 ratio to either Conventional Diet, Mediterranean diet (MD)-high meal frequency, and MD-physical activity groups. Each intervention aimed at reducing caloric intake by 25%-30% of baseline intake and increase energy expenditure by 400 kcal/70 kg. Patients attended regular visits and were followed-up for 6 months. Increased albuminuria was present in 13.3% of patients, while 32.8% showed hyperfiltration. UACR reduction was associated with higher levels of UACR at baseline but not with changes in liver fat. eGFR decreased in patients presenting hyperfiltration at baseline and was associated with reduction in liver fat and insulin resistance, as well as with increase in energy expenditure (R² = 0.248, p = 0.006). No significant differences were observed between the three treatment groups. In patients with NAFLD and MetS, energy expenditure significantly reduced hepatic fat accumulation and insulin resistance, which reduced glomerular hyperfiltration. Increased albuminuria was reduced, but it was not associated with reduced liver fat.

Glomerular hyperfiltration with hyperglycemia in the spontaneously diabetic Torii (SDT) fatty rat, an obese type 2 diabetic model

Glomerular hyperfiltration is observed in an early stage of kidney diseases including diabetic nephropathy. A better understanding of pathophysiological changes in glomerular hyperfiltration is essential for development of new therapies to prevent kidney disease progression. In this study, we investigated glomerular changes including glomerular filtration rate (GFR) and glomerular size in the Spontaneously Diabetic Torii (SDT) fatty rat, an obese type 2 diabetic model, and we also evaluated pharmacological effects of the sodium glucose cotransporter 2 inhibitor dapagliflozin on the renal lesions. Dapagliflozin was administered to SDT fatty rats from 5 to 17 weeks of age. Blood and urinary biochemical parameters were periodically measured. GFR was determined by transdermal GFR monitor at 16 weeks of age and histopathological analysis was performed at 17 weeks of age. SDT fatty rat developed severe hyperglycemia and exhibited pathophysiological abnormalities in the kidney, such as an increased GFR, glomerular hypertrophy and tissue lesions. Dapagliflozin achieved good glycemic control during the experimental period, inhibited the increase in GFR, and improved histopathological abnormalities in tubules. These results suggest that the SDT fatty rat is a useful model for analyzing the pathogenesis of diabetic nephropathy during its early stage and dapagliflozin improves not only hyperglycemia but also glomerular hyperfiltration and tubule lesions in SDT fatty rat.

Efficacy, safety and response predictors of adjuvant astragalus for diabetic kidney disease (READY): study protocol of an add-on, assessor-blind, parallel, pragmatic randomised controlled trial

INTRODUCTION

Diabetic kidney disease (DKD) is a prevalent and costly complication of diabetes with limited therapeutic options, being the leading cause of end-stage kidney disease in most developed regions. Recent big data studies showed that add-on Chinese medicine (CM) led to a reduced risk of end-stage kidney disease and mortality among patients with chronic kidney disease (CKD) and diabetes. Astragalus, commonly known as huang-qi, is the most prescribed CM or used dietary herb in China for diabetes and DKD. In vivo and in vitro studies showed that astragalus ameliorated podocyte apoptosis, foot process effacement, mesangial expansion, glomerulosclerosis and interstitial fibrosis. Nevertheless, the clinical effect of astragalus remains uncharacterised. This pragmatic clinical trial aims to evaluate the effectiveness of add-on astragalus in patients with type 2 diabetes, stage 2-3 CKD and macroalbuminuria, and to identify related response predictors.

METHODS AND ANALYSIS

This is an add-on, assessor-blind, parallel, pragmatic randomised controlled clinical trial. 118 patients diagnosed with DKD will be recruited and randomised 1:1 to receive 48 weeks of add-on astragalus or standard medical care. Primary endpoints are the changes in estimated glomerular filtration rate and urine albumin-to-creatinine ratio between baseline and treatment endpoint. Secondary endpoints include adverse events, fasting blood glucose, glycated haemoglobin, lipids and other biomarkers. Adverse events are monitored through self-complete questionnaire and clinical visits. Outcomes will be analysed by regression models. Subgroup and sensitivity analyses will be conducted for different epidemiological subgroups and statistical analyses. Enrolment started in July 2018.

ETHICS AND DISSEMINATION

This study was approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West/East/Kowloon Central clusters (UW 16-553/HKEC-2019-026/REC (KC/KE)-19-0049/ER-4). We will report the findings in medical journals and conferences. The dataset will be available on reasonable request.

TRIAL REGISTRATION NUMBER

NCT03535935.

Tenofovir disoproxil fumarate associated nephrotoxicity: a retrospective cohort study at two referral hospitals in Namibia

INTRODUCTION

The incidence and risk factors of tenofovir disoproxil fumarate (TDF)-related renal impairment (RI) in Namibia are unknown where TDF-containing ART regimens are used as the first line for HIV.

METHODOLOGY

A retrospective cohort study among HIV-infected patients at two intermediate hospitals. A decline in estimated glomerular filtration rate (eGFR) was significant if it was ≥25% and included a change to a lower eGFR stage. New-onset RI was defined as an eGFR <50 mL/min/1.73m² .

RESULTS

10 387 patients were included: 11.4% (n = 1182) experienced the decline in eGFR. Of these, 0.6% (n = 62) migrated to eGFR stages IV and V. The incidence was 4.5 (95% CI: 4.3-4.8) per 100 patient years. RI developed in 400 patients for an incidence rate of 2.4 (95% CI: 2.2-2.6) cases per 100 patient years. Risk factors with effect sizes >2.0, for decline-in-eGFR were baseline eGFR >60 (aHR = 15.6); hyperfiltration (aHR = 5.0); and pregnancy (aHR = 2.4); while for RI, they were hyperfiltration (aHR = 4.1) and pregnancy (aHR = 29).

CONCLUSION

The incidence of decline-in-eGFR was higher than in other sub-SSA countries, but not RI. A high baseline eGFR had the greatest risk for the decline, and hyperfiltration for the RI.

Early life exposure to per- and polyfluoroalkyl substances (PFAS) and latent health outcomes: A review including the placenta as a target tissue and possible driver of peri- and postnatal effects

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous drinking water contaminants of concern due to mounting evidence implicating adverse health outcomes associated with exposure, including reduced kidney function, metabolic syndrome, thyroid disruption, and adverse pregnancy outcomes. PFAS have been produced in the U.S. since the 1940s and now encompass a growing chemical family comprised of diverse chemical moieties, yet the toxicological effects have been studied for relatively few compounds. Critically, exposures to some PFAS in utero are associated with adverse outcomes for both mother and offspring, such as hypertensive disorders of pregnancy (HDP), including preeclampsia, and low birth weight. Given the relationship between HDP, placental dysfunction, adverse health outcomes, and increased risk for chronic diseases in adulthood, the role of both developmental and lifelong exposure to PFAS likely contributes to disease risk in complex ways. Here, evidence for the role of some PFAS in disrupted thyroid function, kidney disease, and metabolic syndrome is synthesized with an emphasis on the placenta as a critical yet understudied target of PFAS and programming agent of adult disease. Future research efforts must continue to fill the knowledge gap between placental susceptibility to environmental exposures like PFAS, subsequent perinatal health risks for both mother and child, and latent health effects in adult offspring.

Transtubular potassium gradient predicts kidney function impairment after adrenalectomy in primary aldosteronism

Background:

In primary aldosteronism (PA), kidney function impairment could be concealed by relative hyperfiltration and emerge after adrenalectomy. We hypothesized transtubular gradient potassium gradient (TTKG), a kidney aldosterone bioactivity indicator, could correlate to end organ damage and forecast kidney function impairment after adrenalectomy.

Methods:

In the present prospective study, we enrolled lateralized PA patients who underwent adrenalectomy and were followed up 12 months after operation in the Taiwan Primary Aldosteronism Investigation (TAIPAI) registry from 2010 to 2018. The clinical outcome was kidney function impairment, defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² at 12 months after adrenalectomy. End organ damage is determined by microalbuminuria and left ventricular mass.

Results:

In total, 323 patients [mean, 50.8 ± 10.9 years old; female 178 (55.1%)] were enrolled. Comparing pre-operation and post-operation data, systolic blood pressure, serum aldosterone, urinary albumin to creatinine ratio and eGFR decreased. TTKG ⩾ 4.9 correlated with pre-operative urinary albumin to creatinine ratio >50 mg/g [odds ratio (OR) = 2.42; p = 0.034] and left ventricular mass (B = 20.10; p = 0.018). Multivariate logistic regression analysis demonstrated that TTKG ⩾ 4.9 could predict concealed chronic kidney disease (OR = 5.42; p = 0.011) and clinical success (OR = 2.90, p = 0.017) at 12 months after adrenalectomy.

Conclusions:

TTKG could predict concealed kidney function impairment and cure of hypertension in PA patients after adrenalectomy. TTKG more than 4.9 as an adverse surrogate of aldosterone and hypokalaemia correlated with pre-operative end organ damage in terms of high proteinuria and cardiac hypertrophy.

Renal hyperfiltration as a risk factor for chronic kidney disease: A health checkup cohort study

Introduction

Renal hyperfiltration (RHF) has been found to be an independent predictor of adverse cardiovascular outcome. However, it remains uncertain whether it is precursor of chronic kidney disease (CKD) in a healthy population.

Materials and methods

To determine relative risks and identify the predictor of incident proteinuria and decline of estimated glomerular filtration rate (eGFR) in subjects with RHF. A total of 55,992 subjects aged ≥20 years who underwent health check-up during 2004–2017 were included. Among them, 16,946 subjects who completed at least two health checkups were analyzed.

Results

A total of 949 (5.6%) subjects developed proteinuria and 98 (0.6%) subjects showed ≥ 30% of eGFR decline. The risk of incident proteinuria was significantly higher in those with RHF (RR: 1.644; 95% CI: 1.064–2.541). Those with RHF showed 8.720 fold (95% CI: 4.205–18.081) increased risk for ≥30% decline. ESR, CRP, and monocyte count showed reversed J shaped curve according to the increase of eGFR. The adjusted mean of monocyte count was significantly higher in participants with eGFR ≥90ml/min/1.73m² or < 60ml/min/1.73m² compared to that in patients with eGFR 75-89ml/min/1.73m². Compared to subjects with the lowest tertile of monocyte and no RHF, those with the highest tertile of monocyte count in the RHF group had 3.314-fold (95% CI: 1.893–5.802) higher risk of incident proteinuria and 3.822-fold (95% CI, 1.327–11.006) risk of 30% eGFR decline.

Conclusions

RHF had significantly increased risk of developing proteinuria and CKD in healthy subjects. Higher monocyte count might be used as a predictor of CKD in subjects with RHF.

Kidney Function and Arterial Calcification in Major Vascular Beds

Background

The purpose of this study was to investigate the association between kidney function and arterial calcification in major vascular beds and to establish whether arterial calcification mediates the relation between kidney function measures and cardiovascular disease (CVD) incidence.

Methods and Results

In 2241 participants from the Rotterdam Study (mean age 69 years, 52% female), kidney function was assessed using the estimated glomerular filtration rate and urine albumin‐to‐creatinine ratio. All participants underwent noncontrast computed tomography to quantify the amount of arterial calcification in the coronary arteries, aortic arch, extracranial, and intracranial internal carotid arteries. We used linear regression models, adjusted for age, sex, and cardiovascular risk factors, to evaluate the association between kidney function and arterial calcification volume in the 4 vessel beds. Incidence rate of CVD was calculated in 3 groups of participants based on their kidney function and presence of arterial calcification. We conducted mediation analysis to evaluate whether arterial calcification mediates this association. We found that in age‐ and sex‐adjusted models, lower estimated glomerular filtration rate and higher albumin‐to‐creatinine ratio were associated with larger calcification volumes in all 4 vascular beds. Adjusting for cardiovascular risk factors attenuated the effect estimates. CVD incidence was higher in participants with estimated glomerular filtration rate <60 mL/min per 1.73 m² and presence of arterial calcification compared with individuals with estimated glomerular filtration rate >60 and no calcification. After adjusting for cardiovascular risk factors, arterial calcification did not mediate the association between kidney function measures and CVD incidence.

Conclusions

The association of impaired kidney function and larger volumes of arterial calcification is partly explained by cardiovascular risk factors. Arterial calcification does not mediate the association between kidney function and CVD beyond cardiovascular risk factors.