Microalbuminuria: causes and implications

Evaluation of a multiplexed assay for six urinary proteins based on liquid microarray analysis technology

Proteinuria serves as a critical indicator in the progression of chronic kidney disease. The quantification of urinary protein is instrumental in diagnosing kidney disease and monitoring therapeutic efficacy. Nephelometry and turbidimetric immunoassay are predominantly employed for the quantitative detection of various urinary proteins. We developed a quantitative detection method for six proteins in urine utilizing the flow fluorescence luminescence method on the Luminex®200™ detection platform. This study aims to evaluate the clinical performance and accuracy of the method. The sensitivity, precision, recovery, linearity, and interference metrics for the method meet the needs of clinical applications. The correlation coefficient (r) between the results of the method and nephelometry immunoassay on SIEMENS BNII platform ranged from 0.9375 to 0.9847, indicating a strong linear relationship. The results of the Bland-Altman analysis indicated that the systematic bias between the two methods was minimal. Additionally, Passing-Bablok regression analysis, both including and excluding outliers, was conducted on the clinical trial data. The findings demonstrated consistency between the two methods, with the expected confidence interval of bias remaining within the allowable error limits, indicating no significant discrepancy. This urine six protein quantification method demonstrates satisfactory performance, meeting the standards necessary for medical diagnosis and clinical application.

Effects of APOE isoforms in diabetic nephropathy patients of South India

BACKGROUND

Diabetic nephropathy (DN) is a grave complication and the most common renal dysfunction of diabetes mellitus. Genetic factors, including Apolipoprotein E (APOE) isoforms, have been implicated in the pathogenesis of DN.

METHODS

A total of 577 type 2 Diabetes mellitus subjects were categorized into diabetes non-nephropathic (Controls: n = 321), diabetes nephropathic (DN: n = 256) groups. Demographic, clinical, and biochemical parameters including age, BMI, lipid profiles (TC, LDL-C, HDL-C, TG), glucose metabolism (plasma glucose, HbA1c, serum insulin), renal function (UACR, PCR), and blood pressure (SBP, DBP) were assessed. APOE variant frequencies were determined using restriction fragment length polymorphism (RFLP) analysis, validated against Hardy-Weinberg equilibrium (HWE), and statistically correlated with each clinical and biochemical parameter.

RESULTS

The DN group had an increased prevalence of hypertension, fatty liver, and dyslipidemia compared to the Control group. Biochemical analyses revealed elevated levels of TC (213.41 mg/dL vs. 189.32 mg/dL), LDL-C (134.46 mg/dL vs. 107.56 mg/dL), and reduced HDL-C (58.13 mg/dL vs. 65.32 mg/dL) in DN cases compared to Controls (all p < 0.0001). The APOE variants distribution showed a significant increase in E2 allele frequency (69.1% vs. 15.3%) and corresponding homozygous genotype (E2/2: 42.2% vs. 5.6%) in DN cohorts.

CONCLUSION

The study found a higher frequency of E2 allele in the DN group compared to Controls, though no statistically significant risk of DN was linked to this allele. The results suggest a potential association for APOE polymorphisms, requiring broader studies to clarify the role of APOE polymorphisms in DN susceptibility.

1,4-Dihydropyridine-based FA1 site-specific fluorescent probes for the selective detection and quantification of HSA levels in biofluids

Human serum albumin (HSA) is a multifunctional circulatory protein essential for many physiological processes including oncotic pressure maintenance, ligand/drug binding and transport, antioxidant activity, etc. Abnormal HSA levels in biological fluids have been reported in a variety of clinical disorders, making it a potential biomarker for early diagnosis. Low serum albumin levels have been linked to increased long- and short-term mortality rates in ICU patients. Therefore, quantifying HSA in biofluids such as serum and urine offers a convenient approach for the early identification of underlying clinical conditions and assessing the risk factors. Herein, we report a series of fluorescent 1,4-dihydropyridine (DHP) derivatives for the detection and quantification of HSA in biofluids. Their response towards HSA can be tuned by varying the substituents at the C-4 and the N-1 of the DHP ring. Depending on the nature of the substituents, they generated either a turn-on or ratiometric response with a LoD in low nanomolar or subnanomolar levels. A pair of enantiomers obtained by introducing a chiral center on the N-substituents highlighted the importance of stereochemistry in HSA-ligand interactions. Quantification of HSA in complex biofluids, such as blood serum and urine, was also accomplished using these probes. The high selectivity of some of the probes towards HSA over the homologous BSA allowed the discrimination of these two proteins. The preferred binding location of the probes was the hemin binding site and the detection mechanism was identified as the restriction of intramolecular rotation. Additionally, a prototype of a smartphone-integrated point-of-care device was also fabricated to demonstrate the feasibility of utilizing these probes in clinical settings.

Adiponectin Reduces Glomerular Endothelial Glycocalyx Disruption and Restores Glomerular Barrier Function in a Mouse Model of Type 2 Diabetes

Adiponectin has vascular anti-inflammatory and protective effects. Although adiponectin protects against the development of albuminuria, historically, the focus has been on podocyte protection within the glomerular filtration barrier (GFB). The first barrier to albumin in the GFB is the endothelial glycocalyx (eGlx), a surface gel-like barrier covering glomerular endothelial cells (GEnCs). In diabetes, eGlx dysfunction occurs before podocyte damage; hence, we hypothesized that adiponectin could protect from eGlx damage to prevent early vascular damage in diabetic kidney disease (DKD). Globular adiponectin (gAd) activated AMPK signaling in human GEnCs through AdipoR1. It significantly reduced eGlx shedding and the tumor necrosis factor-α (TNF-α)-mediated increase in syndecan-4 (SDC4) and MMP2 mRNA expression in GEnCs in vitro. It protected against increased TNF-α mRNA expression in glomeruli isolated from db/db mice and against expression of genes associated with glycocalyx shedding (namely, SDC4, MMP2, and MMP9). In addition, gAd protected against increased glomerular albumin permeability (Ps'alb) in glomeruli isolated from db/db mice when administered intraperitoneally and when applied directly to glomeruli (ex vivo). Ps'alb was inversely correlated with eGlx depth in vivo. In summary, adiponectin restored eGlx depth, which was correlated with improved glomerular barrier function, in diabetes.

ARTICLE HIGHLIGHTS

Association between continuous glucose monitoring-derived glycemic control indices and urinary biomarkers of diabetic kidney disease: Hyogo Diabetes Hypoglycemia Cognition Complications study

AIMS

Glomerular damage and proximal tubular damage play an important role in the pathogenesis of diabetic kidney disease. This study aimed to investigate the relationship between the urinary markers of proximal tubular injury, including urinary liver-type fatty acid-binding protein-to-creatinine ratio (uL-FABP/Cr) and urinary N-acetyl-β-D-glucosaminidase-to-creatinine ratio (uNAG/Cr), and glycemic control status.

METHODS

This cross-sectional study included 245 and 39 patients with type 2 diabetes mellitus (T2DM) and non-T2DM (NDM), respectively. The participants of this study were fitted with retrospective CGM, and glycemic control indices, such as time in range (TIR) and glycemia risk index (GRI), were calculated.

RESULTS

The results were presented as medians (interquartile ranges). The uL-FABP/Cr was significantly higher in the microalbuminuria than in the normo-albuminuria group [4.2 (2.7-7.1) and 2.2 (1.4-3.4) μg/gCr, respectively, P < 0.001], while the uNAG/Cr in the normo-albuminuria group [6.3 (4.5-10.1) U/gCr] was significantly higher than that in the NDM group [5.3 (3.8-6.3) U/gCr, P = 0.048] but significantly lower than that in the microalbuminuria group [9.2 (6.4-11.1) U/gCr, P = 0.004]. The multivariate logistic regression analysis indicated that CGM-derived TIR was significantly associated with the urinary albumin-to-creatinine ratio [uAlb/Cr, odds ratio (OR) 0.985, 95% confidence interval (CI) 0.971-0.998, P = 0.029] and uNAG/Cr (OR 0.973, 95% CI 0.957-0.989, P = 0.001) independent of renal function. GRI was similarly associated with uAlb/Cr and uNAG/Cr.

CONCLUSION

The findings of this study indicated that uNAG/Cr was elevated before albuminuria development and was associated with CGM-derived TIR and GRI.

A quantitative assessment of renal function utilizing albuminuria in pediatric heart transplant recipients

INTRODUCTION

Kidney disease is common after pediatric heart transplantation. Serum creatinine-based glomerular filtration rate is the most frequently reported measure of kidney function. Albuminuria is an additional marker of kidney dysfunction and is not well described in this population. In this study, we evaluate the prevalence and degree of albuminuria and describe clinical factors associated with albuminuria in a cohort of pediatric heart transplant recipients.

METHODS

This was a cross-sectional study of pediatric heart transplant recipients. Albuminuria was assessed using spot urine albumin-to-creatinine ratio collected at the most recent annual screening cardiac catheterization through August 2019.

RESULTS

In 115 patients at a median duration of 10.2 years post-transplant, 39% had albuminuria. Stage 3 or greater chronic kidney disease was present in 6%. The immunosuppressive regimen at the time of measurement contained a calcineurin inhibitor (CNI) in 88% and a proliferation signal inhibitor (PSI) in 62%. In multivariable modeling, lower eGFR, PSI use, and younger age at transplant were associated with higher levels of albuminuria, whereas CNI use was associated with lower levels of albuminuria.

CONCLUSION

Albuminuria is a prevalent finding in medium-term follow up of pediatric heart transplant recipients, reflecting kidney injury, and is associated with other markers of kidney dysfunction, such as low eGFR. Younger age at transplant, lower eGFR, and PSI use were among the associations with albuminuria.

Prevalence and Determinants of Endothelial Dysfunction among Adults Living with HIV in Northwest Nigeria

Background

Endothelial dysfunction constitutes an early pathophysiological event in atherogenesis and cardiovascular disease. This study aimed to assess the prevalence, determinants, and degree of endothelial dysfunction in antiretroviral therapy (ART)-treated people living with HIV (PLWH) in northwestern Nigeria using brachial flow-mediated dilatation (FMD).

Methods

This was a comparative, cross-sectional study. A total of 200 ART-treated adults living with HIV with no evidence of kidney disease were compared with 200 HIV-negative participants attending a tertiary hospital in Kano, Nigeria, between September 2020 and May 2021. Endothelial function was evaluated by measuring FMD with a high-resolution vascular ultrasound transducer. FMD was calculated as the ratio of the brachial artery diameter after reactive hyperemia to baseline diameter and expressed as a percentage of change. Blood and urine samples were obtained from participants in both arms. Urine albumin-to-creatinine ratio (uACR) was calculated using the 2021 CKD-EPI estimated glomerular filtration rate (eGFR) creatinine-cystatin C equation without the race variable, and low-density lipoprotein (LDL) cholesterol was measured using enzymatic method.

Results

The overall mean age (± standard deviation) of the study participants was 42 ± 11 years. Participants in the comparison arm were younger than PLWH (38 ± 11 versus 46 ± 10 years, respectively). The median (interquartile range) uACR was 41.6 (23.2-162.9) mg/g for the ART-treated PLWH versus 14.5 (7.4-27.0) mg/g for healthy controls. PLWH had a significantly lower mean percent FMD when compared to HIV-negative participants (9.8% ± 5.4 versus 12.1% ± 9.2, respectively). Reduced FMD was independently associated with HIV infection (β = -2.83%, 95% CI, -4.44% to -1.21%, p = 0.001), estimated glomerular filtration rate (β = -0.04%, 95% CI, -0.07% to -0.01%, p = 0.004) and LDL cholesterol (β = -1.12%, 95% CI, -2.13% to -0.11%, p = 0.029).

Conclusion

HIV-positive status, lower estimated GFR, and higher LDL cholesterol levels were independently associated with endothelial dysfunction. Future prospective studies with larger cohorts of persons living with HIV (and age- and sex-matched HIV-negative controls) are needed to gain further insight into these important findings. In the interim, aggressive management of modifiable risk factors is warranted.

Association between Hypokalemia and Albuminuria in a Japanese General Population

INTRODUCTION

Hypokalemia is associated with an increased risk of chronic kidney disease (CKD) and is a risk factor for mortality. Albuminuria is an early manifestation of CKD. We investigated the association between hypokalemia and the prevalence of albuminuria in a Japanese general population.

METHODS

We analyzed the data of 18,289 subjects who underwent annual health checkups in 2018. We categorized them into four groups according to their concentration of serum potassium (sK) and performed a multivariate logistic regression analysis to determine the association between hypokalemia and the prevalence of albuminuria in this population. Hypokalemia was defined as having an sK = 3.1-3.5 mEq/L. After dividing the subjects into those with/without renal dysfunction, those with/without hypertension, and those with/without hyperglycemia, we examined the association between hypokalemia and albuminuria in each group.

RESULTS

Compared to the subjects with sK = 4.1-4.5 mEq/L, the subjects with hypokalemia had a significantly high prevalence of albuminuria: multivariable-adjusted odds ratio (OR) = 2.70 (95% confidence interval [CI] 1.84-3.96). The subgroup analyses showed the following multivariable-adjusted ORs (95% CIs) of the subjects: without renal dysfunction, 3.08 (2.00-4.73); with renal dysfunction, 2.05 (0.89-4.69); without hypertension, 2.89 (1.36-6.16); with hypertension, 2.60 (1.67-4.04); without hyperglycemia, 2.49 (1.62-3.84); and with hyperglycemia, 3.55 (1.43-8.79).

CONCLUSIONS

Hypokalemia was significantly associated with the high prevalence of albuminuria in general population. Regardless of the presence/absence of renal dysfunction, hypertension, or hyperglycemia, hypokalemia was positively associated with the prevalence of albuminuria, and the associations were significant except for the subjects with renal dysfunction.

Kidney function and renal resistive index in children with juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a common pediatric rheumatic disease. Renal manifestations have been rarely observed in JIA, although amyloidosis could be a renal complication in systemic JIA (sJIA). To investigate renal damage in JIA children and to establish the relationship with treatment. Blood urea nitrogen (BUN), creatinine, cystatin C (CysC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), urinary albumin excretion (UAE), estimated glomerular filtration rate (eGFR), and renal resistive index (RRI) were assessed in 49 JIA children (9 boys/40 girls, mean age 10.3 ± 3.8 years) and in 49 healthy controls (24 boys/25 girls, mean age 11.3 ± 3.4 years). Twenty-two JIA patients were on methotrexate (MTX) therapy (group A) and 27 on biologic drugs (group B). CysC and BUN (respectively, 0.8 ± 0.1 vs. 0.7 ± 0.1 mg/dl; 13.3 ± 2.9 vs. 11.7 ± 1.4 mg/dl) were higher (p ≤ 0.001) whereas creatinine and eGFR (respectively, 0.5 ± 0.1 vs. 0.6 ± 0.1 mg/dl; 99.2 ± 10.5 vs. 122.5 ± 19.8 ml/min/1.73 m²) were lower in JIA children as compared to controls (p < 0.001). UAE resulted higher in patients than in controls (p = 0.003). Mean RRI was higher in JIA children than controls (0.7 ± 0.04 vs. 0.6 ± 0.04; p < 0.001). Group B showed higher mean RRI than group A (0.7 ± 0.1 vs. 0.7 ± 0.04; p < 0.001). Associations were found between RRI and ESR, JADAS-27, disease state, BMI-SDS (p < 0.001), CRP (p = 0.003) and eGFR (p = 0.001). JIA children had reduced eGFR, increased UAE and higher RRI values, than controls. RRIs were higher in patients on biologic drugs than MTX group and were associated with inflammation indexes and disease state, suggesting a direct effect of the disease.

The microvascular endothelial glycocalyx: An additional piece of the puzzle in veterinary medicine

The endothelial glycocalyx (eGlx) is a critically important structure lining the luminal surface of endothelial cells. There is increasing evidence, in human patients and animal models, for its crucial role in the maintenance of health. Moreover, its damage is associated with the pathogenesis of multiple disease states. This review provides readers with an overview of the eGlx; summarising its structure, essential functions, and evidence for its role in disease. We highlight the lack of studies regarding the eGlx in cats and dogs, particularly in naturally occurring diseases. Importantly, we discuss techniques to aid its study, which can be applied to veterinary species. Finally, we present targeted therapies aimed at preserving, and in some cases, restoring damaged eGlx.

Dehydration Status Aggravates Early Renal Impairment in Children: A Longitudinal Study

Dehydration is common in children for physiological and behavioral reasons. The objective of this study was to assess changes in hydration status and renal impairment across school weekdays. We conducted a longitudinal study of three repeated measures of urinalysis within one week in November 2019 in a child cohort in Beijing, China. We measured urine specific gravity (USG) to determine the dehydration status, and the concentration of β₂-microglobulin (β₂-MG) and microalbumin (MA) to assess renal function impairment among 1885 children with a mean age of 7.7 years old. The prevalence of dehydration was 61.9%, which was significantly higher in boys (64.3%). Using chi-square tests and linear mixed-effects regression models, we documented the trends of the renal indicators’ change over time among different hydration statuses. Compared to Mondays, there were apparent increases of β₂-MG concentrations on Wednesdays (β = 0.029, p < 0.001) and Fridays (β = 0.035, p < 0.001) in the dehydrated group, but not in the euhydrated group. As for the MA concentrations, only the decrease on Fridays (β = −1.822, p = 0.01) was significant in the euhydrated group. An increased trend of elevated β₂-MG concentration was shown in both the euhydrated group (Z = −3.33, p < 0.001) and the dehydrated group (Z = −8.82, p < 0.001). By contrast, there was a decreased trend of elevated MA concentrations in the euhydrated group (Z = 3.59, p < 0.001) but not in the dehydrated group. A new indicator ratio, β₂-MG/MA, validated the consistent trends of renal function impairment in children with dehydration. Renal impairment trends worsened as a function of school days during the week and the dehydration status aggravated renal impairment during childhood across school weekdays, especially tubular abnormalities in children.

Microalbuminuria and Urinary Neutrophil Gelatinase-associated Lipocalin (uNGAL) in human immunodeficiency virus infected children

Introduction:

Renal dysfunction and progression to end stage renal disease is well known in human immunodeficiency virus (HIV) infection. We studied the role of microalbuminuria and urinary NGAL levels in children with HIV infection for the prediction of renal dysfunction.

Design and Methods:

A cross-sectional study was carried out and 60 HIV infected children, aged (18 months to 15 years) were screened for microalbuminuria by nephelometry and for uNGAL by ELISA. Thirty healthy children were screened for uNGAL for normative data in Indian children.

Results:

The prevalence of microalbuminuria in studied population was 3.3%. The mean uNGAL and uNGAL/creatinine in study population was higher than controls (26.94 ± 93.12 ng/ml vs. 88.94 ± 345.20 mcg/g, and 15.53 ± 37.52 ng/ml vs. 30.12 ± 78.66 ng/ml; P = 0.003, P = 0.002). Children with lower CD4 counts had significant higher mean Albumin Creatinine Ratio (ACR) and mean uNGAL; P = 0.03, P = 0.01.

Conclusions:

uNGAL and urine microalbumin are useful biomarkers of early tubular and glomerular injury in children with HIV infection.

The Glomerular Endothelium Restricts Albumin Filtration

Inflammatory activation and/or dysfunction of the glomerular endothelium triggers proteinuria in many systemic and localized vascular disorders. Among them are the thrombotic microangiopathies, many forms of glomerulonephritis, and acute inflammatory episodes like sepsis and COVID-19 illness. Another example is the chronic endothelial dysfunction that develops in cardiovascular disease and in metabolic disorders like diabetes. While the glomerular endothelium is a porous sieve that filters prodigious amounts of water and small solutes, it also bars the bulk of albumin and large plasma proteins from passing into the glomerular filtrate. This endothelial barrier function is ascribed predominantly to the endothelial glycocalyx with its endothelial surface layer, that together form a relatively thick, mucinous coat composed of glycosaminoglycans, proteoglycans, glycolipids, sialomucins and other glycoproteins, as well as secreted and circulating proteins. The glycocalyx/endothelial surface layer not only covers the glomerular endothelium; it extends into the endothelial fenestrae. Some glycocalyx components span or are attached to the apical endothelial cell plasma membrane and form the formal glycocalyx. Other components, including small proteoglycans and circulating proteins like albumin and orosomucoid, form the endothelial surface layer and are bound to the glycocalyx due to weak intermolecular interactions. Indeed, bound plasma albumin is a major constituent of the endothelial surface layer and contributes to its barrier function. A role for glomerular endothelial cells in the barrier of the glomerular capillary wall to protein filtration has been demonstrated by many elegant studies. However, it can only be fully understood in the context of other components, including the glomerular basement membrane, the podocytes and reabsorption of proteins by tubule epithelial cells. Discovery of the precise mechanisms that lead to glycocalyx/endothelial surface layer disruption within glomerular capillaries will hopefully lead to pharmacological interventions that specifically target this important structure.

Prevalence of Microalbuminuria and Its Association with Subclinical Carotid Atherosclerosis in Middle Aged, Nondiabetic, Low to Moderate Cardiovascular Risk Individuals with or without Hypertension

Microalbuminuria is closely associated with the risk of cardiovascular disease and all-cause mortality in the general population. Less is known about its relationship with subclinical atherosclerosis. We aimed to assess the prevalence of microalbuminuria and its relationship with subclinical atherosclerosis in middle-aged, nondiabetic, apparently healthy individuals (N = 187; 40.1% men, 59.9% women; aged 35–55 years) as well as to evaluate its potential associations with established risk modifiers, especially with the presence of carotid plaque. Clinical and laboratory parameters, the estimated 10-year fatal cardiovascular risk (SCORE), as well as circulating, functional (flow mediated vasodilation, ankle-brachial index, augmentation index, and pulse wave velocity), and morphological markers (mean carotid intima–media thickness, and carotid plaque) of subclinical atherosclerosis were analysed in group with vs. without microalbuminuria. Microalbuminuria was present in 3.8% of individuals with SCORE risk 0.43 ± 0.79%. Functional markers predominated in both groups. Carotid intima–media thickness (mean ± SD) in both groups was in range: 0.5–0.55 ± 0.09–0.14 mm. Carotid plaque was more frequent in group with (14.3%) vs. without (4.4%) microalbuminuria. Microalbuminuria had no statistically significant effect on most markers of subclinical atherosclerosis, but the increasing value of microalbuminuria was significantly associated with the occurrence of carotid plaque (p = 0.035; OR = 1.035; 95% CI = 1.002–1.07). Additional multiple logistic regression analysis, where variables belonged to microalbuminuria, number of risk factors, and family history, finally showed only two variables: microalbuminuria (p = 0.034; OR = 1.04; 95%CI = 1.003–1.09) and the number of risk factors (p = 0.006; OR = 2.15; 95% CI = 1.24–3.73) with independent and significant impact on the occurrence of carotid plaque. Our results may indicate an association of microalbuminuria with the presence of carotid atherosclerotic plaque; in addition, microalbuminuria and the number of risk factors appear to be possible predictors of the carotid plaque occurrence. Monitoring microalbuminuria may improve the personalized cardiovascular risk assessment in nondiabetic, low-to-moderate cardiovascular risk individuals with or without hypertension.

Evaluation of microalbuminuria as a prognostic indicator after a TIA or minor stroke in an outpatient setting: the prognostic role of microalbuminuria in TIA evolution (ProMOTE) study

OBJECTIVE

Transient ischaemic attacks (TIA) and minor strokes are important risk factors for further vascular events. We explored the role of albumin creatinine ratio (ACR) in improving risk prediction after a first event.

SETTING

Rapid access stroke clinics in the UK.

PARTICIPANTS

2202 patients attending with TIA or minor stroke diagnosed by the attending stroke physician, able to provide a urine sample to evaluate ACR using a near-patient testing device.

PRIMARY AND SECONDARY OUTCOMES

Primary outcome was major adverse cardiac events (MACE: recurrent stroke, myocardial infarction or cardiovascular death) at 90 days. The key secondary outcome was to determine whether urinary ACR could contribute to a risk prediction tool for use in a clinic setting.

RESULTS

151 MACE occurred in 144 participants within 90 days. Participants with MACE had higher ACR than those without. A composite score awarding a point each for age >80 years, previous stroke/TIA and presence of microalbuminuria identified those at low risk and high risk. 90% of patients were at low risk (scoring 0 or 1). Their 90-day risk of MACE was 5.7%. Of the remaining 'high-risk' population (scoring 2 or 3) 12.4% experienced MACE over 90 days (p<0.001 compared with the low-risk population). The need for acute admission in the first 7 days was twofold elevated in the high-risk group compared with the low-risk group (3.23% vs 1.43%; p=0.05). These findings were validated in an independent historic sample.

CONCLUSION

A risk score comprising age, previous stroke/TIA and microalbuminuria predicts future MACE while identifying those at low risk of a recurrent event. This tool shows promise in the risk stratification of patients to avoid the admission of low-risk patients.

Are point-of-care urine albumin-creatinine ratio measurements accurate in the critically ill?

BACKGROUND

In the critical care environment, elevated albuminuria values show capacity to reflect illness severity and predict mortality and hence assessing albumin/creatinine ratio (ACR) at the bedside has potential clinical benefit Point-of-care (POC) analysers offer rapid results but may be less accurate then laboratory analysis.

METHODS

Critically ill adult patients with a urinary catheter in situ had albumin, creatinine, and ACR measurements performed via laboratory and POC analysis. Data are presented as mean (standard deviation) or median [interquartile range]. Measurement agreement was assessed by Lin's concordance correlation coefficient, Bland Altman 95% limits of agreement, and classification by Cohen's kappa statistic.

RESULTS/FINDINGS

Albumin, creatinine, and ACR analysis was performed for 30 patients. Lin's correlation coefficient showed 'substantial' agreement for albumin and ACR and 'almost perfect' agreement for creatinine for POC vs laboratory analysis. POC vs laboratory analysis also showed poor agreement for identification of normal ACR (>1 mg/mmol) and mild urine ACR (1-3 mg/mmol) and 'substantial' agreement for moderately increased urine ACR (3-30 mg/mmol).

CONCLUSIONS

ACR POC values appear to provide an accurate and rapid method that has potential to provide an early indication of injury severity and mortality risk in the critically ill.

Dietary inflammation and cardiometabolic health in adolescents

BACKGROUND

The Children's Dietary Inflammatory Index (C-DII) has been validated to characterize the inflammatory potential of an individual child's diet.

OBJECTIVE

To determine the association between C-DII and markers of cardiometabolic risk (adiposity, blood pressure [BP], lipids, albuminuria, glomerular hyperfiltration) in adolescents.

METHODS

Participants aged 12-18 enrolled in NHANES from 2005 to 2014 who completed a 24-hour dietary recall were included in this cross-sectional study. Regression models adjusted for age, sex, race and height examined associations of C-DII quartiles stratified by weight status.

RESULTS

Among adolescents (mean age 15 years), the average C-DII score was 0.86 (SE 0.04). When comparing C-DII quartile 4 (most pro-inflammatory) to quartile 1 (most anti-inflammatory), there was a positive association with albuminuria (OR 1.44, 95% CI 1.02, 2.03). After stratifying by weight status, C-DII quartile was found to be significantly associated with albuminuria (OR 4.27, 95% CI 1.83, 9.92) and dyslipidemia (OR 1.87, 95% CI 1.15, 3.03) in adolescents who were overweight. Among adolescents with obesity, C-DII quartile was associated with higher SBP (β = 5.07, 95% CI 2.55-7.59) and lower DBP (β = -4.14, 95% CI -6.74, -1.54).

CONCLUSION

Consuming a pro-inflammatory diet in adolescence was associated with alterations in albuminuria, lipid and BP measures.

Relationship between Endothelial Function, Antiretroviral Treatment and Cardiovascular Risk Factors in HIV Patients of African Descent in South Africa: A Cross-Sectional Study

Limited information on the effect of antiretroviral treatment (ART) on vascular function in South Africans of African descent living with human immunodeficiency virus (HIV) is available. The relationship between ART, vascular function and cardiovascular risk factors in South Africans of African ancestry with HIV was therefore studied. This cross-sectional study recruited 146 HIV-positive individuals on ART (HIV⁺ART⁺), 163 HIV-positive individuals not on ART (HIV⁺ART⁻) and 171 individuals without HIV (HIV⁻) in Mthatha, Eastern Cape Province of South Africa. Flow-mediated dilation (FMD) test was performed to assess endothelial function. Anthropometry and blood pressure parameters were measured. Lipid profile, glycaemic indices, serum creatinine as well as CD4 count and viral load were assayed in blood. Urinary albumin to creatinine ratio (ACR) was determined as a marker of cardiovascular risk. Obesity and albuminuria were positively associated with HIV, and HIV⁺ART⁺ participants had significantly higher HDL cholesterol. Dyslipidaemia markers were significantly higher in hypertensive HIV⁺ART⁺ participants compared with the controls (HIV⁺ART⁻ and HIV⁻ participants). FMD was not different between HIV⁺ART⁺ participants and the controls. Moreover, HIV⁺ART⁺ participants with higher FMD showed lower total cholesterol and LDL cholesterol comparable to that of HIV⁻ and HIV⁺ART⁻ participants. A positive relationship between FMD and CD4 count was observed in HIV⁺ART⁺ participants. In conclusion, antiretroviral treatment was associated with cardiovascular risk factors, particularly dyslipidaemia, in hypertensive South Africans of African ancestry with HIV. Although, ART was not associated with endothelial dysfunction, flow-mediated dilatation was positively associated with CD4 count in HIV-positive participants on ART.

Association Between Neck Circumference and Microalbuminuria in Community Residents

OBJECTIVE

Neck circumference (NC) represents the subcutaneous fat deposition in the neck and is an effective indicator for evaluating metabolic disorders, such as metabolic syndrome, subclinical atherosclerosis, and non-alcoholic fatty liver disease. Microalbuminuria (MAU) is regarded as a potential sign of systemic endothelial dysfunction and microvascular abnormalities. The aim of this study was to elucidate the association of NC with urine albumin-to-creatinine ratio (UACR) and MAU.

METHODS

A total of 1882 Shanghai community residents were enrolled (816 men and 1066 women), with age ranging from 40 to 80 years. Anthropometric parameters, including NC, and biochemical indices were measured. MAU was determined if 30 mg/g ≤ UACR < 300 mg/g. An elevated NC was defined as NC ≥ 38.5 cm for men and NC ≥ 34.5 cm for women.

RESULTS

Individuals with an elevated NC had significantly higher prevalence of MAU and UACR values than those with normal NC in both men and women (all P < 0.05). The logistic regression analysis showed that there were significant and positive associations between elevated NC and the increasing risk of MAU after adjusting for lipid profile and glycemic indices (P = 0.007 for men and P = 0.009 for women). After further adjusting for blood pressure, elevated NC caused an 69.3% additional risk of MAU in men (P = 0.037) and the positive correlation in women disappeared (P = 0.131).

CONCLUSION

There was an independent and positive association between elevated NC and the risk of MAU in men in the Chinese community population.

CHINESE CLINICAL TRIAL REGISTRY WWWCHICTRORGCN REGISTRATION NUMBER

ChiCTR1900024011.

Relationship between High Blood Pressure and Microalbuminuria in Children Aged 6-9 Years in a South African Population

Though the association between high blood pressure and microalbuminuria is well established in adults, there is a paucity of information on microalbuminuria in children. This study investigated the relationship between high blood pressure and microalbuminuria in 6-9-year-old children. A cross-sectional study, which included 306 primary school children of age 6-9 years old from urban areas (n = 154) and rural areas (n = 152) of the Eastern Cape Province of South Africa, was conducted. Participants' anthropometric data were determined and systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured and converted to BP percentiles for age, sex and height. Creatinine and albumin concentrations were assayed in early morning midstream urine and the albumin to creatinine ratio (ACR) was calculated. There was a 42.8% prevalence of elevated blood pressure/high blood pressure (E-BP/H-BP) and a 10.1% prevalence of microalbuminuria. Among the 131 children with E-BP/H-BP, 17 had elevated ACR with a prevalence of 13.95%. SBP and HR increased with increasing range of ACR and, furthermore, SBP was significantly (p < 0.05) higher in children with moderately and severely increased ACR. SBP was associated with ACR and increased SBP predicted microalbuminuria (R2 = 0.42, adj R2 = 0.039, B: 0.120, p = < 0.05). In conclusion, microalbuminuria was present in 6-9-year-old South African children of African Ancestry and a weak association was observed with SBP in children.

A higher level of serum furin indicates a higher risk of microalbuminuria: results from a longitudinal study in Chinese adults

BACKGROUND

Furin, a key enzyme of natriuretic peptide system, has been suggested to play a role in microalbuminuria, but the association between furin and microalbuminuria has been scarcely studied.

METHODS

Leveraging a longitudinal cohort of Chinese adults who had urinary albumin measured twice 4 years apart, we examined the cross-sectional and prospective associations of baseline serum furin with microalbuminuria, adjusting for age, sex, education level, smoking, drinking, obesity, blood pressure, glucose, lipids, and antihypertensive medications.

RESULTS

The cross-sectional analysis in 2175 participants (53 ± 10 years, 38% men) found that a 10-time higher level of serum furin was significantly associated with a 64% higher risk of having microalbuminuria (OR = 1.64, P = 0.005). The longitudinal analysis found a positive association between baseline serum furin and dynamic elevation of albumin excretion during follow-up. The prospective analysis in 1357 participants free of microalbuminuria at baseline found that a 10-time higher level of serum furin at baseline was significantly associated with a 1.28-time higher risk of developing microalbuminuria 4 years later (OR = 2.28, P < 0.001).

CONCLUSIONS

A higher level of serum furin at baseline predicted an increased risk of developing microalbuminuria in Chinese adults. These findings indicate that furin might be a predictor or a risk factor for microalbuminuria but the causality still needs more investigations.

Lipid Biomarkers as Predictors of Diastolic Dysfunction in Diabetes with Poor Glycemic Control

Uncontrolled type-1 diabetes (T1DM) can lead to dyslipidaemia and albuminuria, which may promote cardiovascular injuries. However, some lipidemic factors could be useful in predicting cardiac dysfunction. Seventy-eight adolescents under insulin treatment due to a 6-year history of T1DM and were retrospectively examined. Glycemia, lipidemia, and albuminuria were measured in addition to development of cardiovascular abnormalities Both girls and boys showed higher HbA1c and fasting blood glucose and 27.1% females and 33.3% males exhibited microalbuminuria though their plasma levels of total cholesterol (TC), triglycerides (TG), and low-density lipoproteins (LDL) and high-density lipoproteins (HDL lipoproteins were in the normal range. They exhibited a preserved systolic function, but 50% of females and 66.6% of males had developed diastolic failures. Interestingly, girls with diastolic dysfunction showed significantly lower concentrations of HDL and higher TC/HDL and TG/HDL ratios. In fact, low HDL levels (OR 0.93; 95% CI 0.88-0.99; p = 0.029) and high TC/HDL (OR 2.55; 95% CI 1.9-5.45; p = 0.016) and TG/HDL (OR 2.74; 95% CI 1.12-6.71; p = 0.028) ratios associated with the development of diastolic complications. The cut-off values for HDL, TC/HDL, and TG/HDL were 49 mg/dL, 3.0 and 1.85, respectively. HDL and TC/HDL and TG/HDL ratios may be useful for predicting diastolic dysfunction in girls with uncontrolled T1DM.

A Novel Near Infrared Spectroscopy Based Device for Albumin Estimation

In this paper we have proposed a fluorescence based spectroscopy device which can be used to quantitatively estimate the amount of albumin that gets excreted out of our body. Albumin is a significant protein in bio-fluids and performs a wide range of metabolic functions. The dye that has been used as a fluorescent indicator for the presence of albumin in this study has been earlier tested with bovine serum albumin (BSA) and human serum albumin (HSA) with satisfactory results. The method is based on principle of fluorescence in near infrared range (NIR) of 700 to 850 nm by using a novel dye with the test mixture. The chosen near infrared range has a benefit of absence of the auto fluorescence of the bio-molecules present in urine other than the albumin molecules. The system consists of: light source, spectroscopic chamber, sensing and computational unit. The study shows the stability and reproducibility of device so as to avoid fluctuations of voltage and other undesirables. The optimization with bovine serum albumin and human serum albumin has been done and the device can sense as low as 100 nM concentration precisely and accurately.Clinical Relevance-The system being presented is intended for developing a low cost point of care testing device for determining albumin concentration in urine.

Subclinical hypothyroidism is associated with albuminuria in Japanese nondiabetic subjects

PURPOSE

Thyroid dysfunction is a risk factor of cardiovascular disease (CVD), and albuminuria is a predictor of CVD. For preventing the CVD, it is essential to clarify from which stage of thyroid dysfunction the risk of CVD starts developing. We thus investigated the association between subclinical thyroid dysfunction and albuminuria, focusing on a nondiabetic general population.

METHODS

We analyzed the data of 17,221 nondiabetic subjects who underwent annual health checkups by multivariate logistic regression analyses.

RESULTS

Compared with the subjects with euthyroidism, those with subclinical hypothyroidism presented a higher prevalence of albuminuria. By a multivariate logistic regression analysis, subclinical hypothyroidism showed a significant and independent association with the high prevalence of albuminuria compared with euthyroidism (OR 1.64, 95% CI 1.21-2.21, p = 0.001). In accord with this result, the analysis in which the lowest quartile of thyroid stimulating hormone (TSH) concentration (<0.96 µIU/mL) was used as a reference revealed that the highest quartile (>2.07 µIU/mL) had a significant and independent association with the prevalence of albuminuria (OR 1.23, 95% CI 1.01-1.51, p = 0.04). One microliter unit per milliliter increase of the serum concentration of TSH also had a significant and independent association with the prevalence of albuminuria (OR 1.07, 95% CI 1.02-1.12, p = 0.006). The association between subclinical hyperthyroidism and the prevalence of albuminuria was not significant.

CONCLUSION

Our data indicated that subclinical hypothyroidism was significantly and independently associated with the high prevalence of albuminuria.

Clinical trial recommendations for potential Alport syndrome therapies

Alport syndrome is experiencing a remarkable increase in preclinical investigations. To proactively address the needs of the Alport syndrome community, as well as offer clarity for future clinical research sponsors, the Alport Syndrome Foundation hosted a workshop to generate consensus recommendations for prospective trials for conventional drugs. Opinions of key stakeholders were carefully considered, including those of the biopharmaceutical industry representatives, academic researchers, clinicians, regulatory agency representatives, and-most critically-patients with Alport syndrome. Recommendations were established for preclinical researchers, the use and selection of biomarkers, standards of care, clinical trial designs, trial eligibility criteria and outcomes, pediatric trial considerations, and considerations for patient engagement, recruitment, and treatment. This paper outlines their recommendations.

Comparative validity of microalbuminuria versus clinical mortality scores to predict pediatric intensive care unit outcomes

BACKGROUND

Predicting the prognosis of patients admitted to the pediatric intensive care unit (PICU) is very important in determining further management and resource allocation. The prognostication of critically ill children can be challenging; hence, accurate methods for predicting outcomes are needed.

PURPOSE

To evaluate the role of microalbuminuria at admission as a prognostic marker in comparison to standard Pediatric Risk of Mortality (PRISM) and Pediatric Logistic Organ Dysfunction (PELOD) mortality scores in children admitted to the PICU.

METHODS

This cross-sectional study was conducted from January 2015 to October 2016. Eighty-four patients aged 1 month to 18 years admitted to the PICU of teaching hospitals for more than 24 hours were enrolled by convenience sampling method. Microalbuminuria was estimated by spot urinary albumin-creatinine ratio. PRISM and PELOD scores were calculated using an online calculator. Outcome measures were PICU length of stay, inotrope usage, multiorgan dysfunction, and survival. ACR was compared with mortality scores for predicting survival.

RESULTS

Microalbuminuria was present in 79.8% with a median value of 85 mg/g (interquartile range, 41.5-254 mg/g). A positive correlation was found between albumin-creatinine ratio and PICU length of stay (P=0.013, r=0.271). Albumin-creatinine ratio was significantly associated with organ dysfunction (P=0.004) and need for inotropes (P=0.006). Eight deaths were observed in the PICU. The area under the curve for mortality for albumin-creatinine ratio (0.822) was comparable to that for PRISM (0.928) and PELOD (0.877). Albumin-creatinine ratio >109 mg/g predicted mortality with a sensitivity of 87.5% and specificity of 63.2%.

CONCLUSION

Microalbuminuria is a good predictor of PICU outcomes comparable with mortality scores.

Genetic characterization of suspected MODY patients in Tunisia by targeted next-generation sequencing

AIMS

Maturity Onset Diabetes of the Young (MODY) is a monogenic form of diabetes with autosomal dominant inheritance pattern. The diagnosis of MODY and its subtypes is based on genetic testing. Our aim was investigating MODY by means of next-generation sequencing in the Tunisian population.

METHODS

We performed a targeted sequencing of 27 genes known to cause monogenic diabetes in 11 phenotypically suspected Tunisian patients. We retained genetic variants passing filters of frequency in public databases as well as their probable effects on protein structures and functions evaluated by bioinformatics prediction tools.

RESULTS

Five heterozygous variants were found in four patients. They include two mutations in HNF1A and GCK that are the causative genes of the two most prevalent MODY subtypes described in the literature. Other possible mutations, including novel frameshift and splice-site variants were identified in ABCC8 gene.

CONCLUSIONS

Our study is the first to investigate the clinical application of targeted next-generation sequencing for the diagnosis of MODY in Africa. The combination of this approach with a filtering/prioritization strategy made a step towards the identification of MODY mutations in the Tunisian population.

Kidney Size, Renal Function, Ang (Angiotensin) Peptides, and Blood Pressure in Young Adults Born Preterm

Preterm birth incurs a higher risk for adult cardiovascular diseases, including hypertension. Because preterm birth may impact nephrogenesis, study objectives were to assess renal size and function of adults born preterm versus full term and to examine their relationship with blood pressure (BP; 24-hour ambulatory BP monitoring) and circulating renin-Ang (angiotensin) system peptides. The study included 92 young adults born (1987-1997) preterm (≤29 weeks of gestation) and term (n=92) matched for age, sex, and race. Young adults born preterm had smaller kidneys (80±17 versus 90±18 cm³/m²; P<0.001), higher urine albumin-to-creatinine ratio (0.70; interquartile range, 0.47-1.14 versus 0.58, interquartile range 0.42 to 0.78 mg/mmol, P=0.007), higher 24-hour systolic (121±9 versus 116±8 mm Hg; P=0.001) and diastolic (69±5 versus 66±6 mm Hg; P=0.004) BP, but similar estimated glomerular filtration rate. BP was inversely correlated with kidney size in preterm participants. Plasma Ang I was higher in preterm versus term participants (36.3; interquartile range, 13.2-62.3 versus 19.4; interquartile range, 9.9-28.1 pg/mL; P<0.001). There was no group difference in renin, Ang II, Ang (1-7), and alamandine. In the preterm, but not in the term group, higher BP was significantly associated with higher renin and alamandine and lower birth weight and gestational age with smaller adult kidney size. Young adults born preterm have smaller kidneys, higher urine albumin-to-creatinine ratio, higher BP, and higher circulating Ang I levels compared with term controls. Preterm young adults with smaller kidneys have higher BP. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT03261609.

Appropriateness of Using Tests for Blood Glucose and Diabetic Complications in Clinical Practice: Experiences in a Hospital in Thailand

BACKGROUND This study aimed to evaluate how the tests for blood glucose (BG) and diabetic complications have been utilized in a hospital in Thailand. MATERIAL AND METHODS Patient medical records having the results of BG, HbA1c, and/or urine microalbumin presented and the records of DM patients having the results of serum lipids, serum LDL-C, and/or serum creatinine presented were selected. The data of diagnosis, ordered tests, and testing results in these records were extracted for evaluation. RESULTS This study recruited 1066 patients diagnosed with DM and 3081 patients diagnosed with other diseases. Point-of-care testing (POCT) for BG was repeatedly used in 371 non-DM cases; most of its results were normal. The results of BG and HbA1c were often used together. There was a good relationship between them, and these test results indicated poor glycemic control in 58% of DM cases. In non-DM cases, the test results agreed, indicating normoglycemia in 17.32%, pre-diabetes in 20.47%, and diabetes in 21.78%. To prevent diabetic nephropathy, serum creatinine was frequently used, whereas urine microalbumin, the recommended test, was underutilized. The result of LDL-C from both direct measurement and calculation were used; however, based on the same guidelines, the results of measured LDL-C indicated risk of cardiovascular diseases in a higher percentage of DM cases than did the results of calculated LDL-C. CONCLUSIONS The use of POCT for BG in hospitalized patients may be inappropriate. The utilization of urine microalbumin should be promoted to effectively prevent diabetic nephropathy.

Correlation between urinary albumin to creatinine ratio and systemic glycocalyx degradation in pediatric sepsis

Background: Increased capillary permeability in sepsis is associated with several complications and worse outcomes. Glycocalyx degradation, marked by increased serum syndecan-1 levels, alters vascular permeability, which can manifest as albuminuria in the glomerulus. Therefore, elevated urinary albumin to creatinine ratio (ACR) potentially provides an index of systemic glycocalyx degradation. The aim of this study was to analyze the correlation between urinary ACR and serum syndecan-1 levels.Methods: A longitudinal prospective study with repeated cross-sectional design was conducted on children with sepsis in pediatric intensive care unit, we evaluated serum syndecan-1 levels and urinary ACR on days 1, 2, 3, and 7. A descriptive study on healthy children was also conducted to determine the reference value of syndecan-1 in children.Results: 49 subjects with sepsis were recruited. Based on the data of the healthy children group (n=30), syndecan-1 level of >90th percentile (41.42 ng/mL) was defined as systemic glycocalyx degradation. The correlation coefficients (r) between urinary ACR and syndecan-1 levels were 0.32 (p<0.001) from all examination days (162 specimens), 0.298 (p=0.038) on day 1, and 0.469 (p=0.002) on day 3. The area under the curve of urinary ACR and systemic glycocalyx degradation was 65.7% (95% CI 54.5%–77%; p=0.012). Urinary ACR ≥157.5 mg/g was determined as the cut-off point for glycocalyx degradation, with a sensitivity of 77.4% and a specificity of 48%.Conclusion: Urinary ACR showed a weak correlation with systemic glycocalyx degradation, indicating that the pathophysiology of elevated urinary ACR in sepsis is not merely related to glycocalyx degradation.

Relationship between serum thyrotropin and urine albumin excretion in euthyroid subjects with diabetes

BACKGROUND

Microalbuminuria represents vascular and endothelial dysfunction. Thyroid hormones can influence urine albumin excretion as it exerts crucial effects on the kidney and on the vascular system. This study explores the relationship between serum thyrotropin and urine albumin excretion in euthyroid patients with diabetes.

METHODS

A total of 433 patients with type 1 or 2 diabetes were included in this retrospective cross-sectional study. Data included anthropometric measurements and biochemical parameters from diabetes clinic. Males with urine albumin creatinine ratio >2.5 and female's >3.5 mg/mmoL were considered to have microalbuminuria.

RESULTS

34.9% of the patients had microalbuminuria. Prevalence of microalbuminuria increased according to TSH quartiles (26.9, 34.6, 38.5 and 44.9%, P for trend = 0.02). In a fully adjusted logistic regression model, higher TSH concentrations were associated with high prevalence of microalbuminuria (adjusted odds ratio 2.06 [95% CI: 1.14-3.72]; P = 0.02), while comparing the highest with the lowest quartile of TSH. Multiple linear regression analysis showed an independent association between serum TSH and urine albumin creatinine ratio (β = 0.007, t = 2.03 and P = 0.04). The risk of having microalbuminuria was higher with rise in TSH concentration in patients with younger age (<65 years), raised body mass index (≥25 kg/m²), hypertension, type 2 diabetes and hyperlipidaemia and age was the most important determinant ( P for interaction = 0.02).

CONCLUSION

Serum TSH even in the euthyroid range was positively associated with microalbuminuria in euthyroid patients with diabetes independent of traditional risk factors. This relationship was strongest in patients with components of the metabolic syndrome.

Early renal damage among children living in the region of highest burden of chronic kidney disease of unknown etiology (CKDu) in Sri Lanka

Background

Chronic kidney disease of unknown origin (CKDu) in Sri Lanka is grouped with several other epidemics of similar nature across the world as Chronic Interstitial Nephritis in Agricultural Communities (CINAC). In CKDu endemic countries, the focus has mainly been on adults. We hypothesized that studying distribution and factors associated with elevated urine albumin to creatinine ratio (UACR), an early marker of kidney injury, among children living in a CKDu endemic area may provide important clues about the onset and progression of the disease.

Methods

This cross sectional study was performed in rural primary schools in North Central Province of Sri Lnaka, a CKDu high endemic region. Total of 2880 students aging 5 to 11 years from 67 schools were enrolled for urinalysis in a random spot urine sample. Bedside Schwartz formula was used to measure estimated glomerular filtration rate (eGFR) on all children with UACR > 30 mg/g in Polonnaruwa district and a group of age matched controls. A standard multiple linear regression using log transformed UACR as the dependent variable was performed. Mean eGFR were compared between UACR elevated group and controls using independent sample t test.

Results

Median UACR was 10.3 mg/g. Sex, ethnicity, history of having a chronic disease and age uniquely contributed to the multiple regression model which only explained 2.8% of the variance in the log of the UACR (p < 0.001). Only 15 (0.5%) had UACR> 300 mg/g while 8.2% (n = 236) had UACR between 30 to 300 mg/g and 89.8% (n = 203) of them did not have a chronic disease (Chi square 2.21, p = 0.091). Mean eGFR was significantly lower in the group with elevated UACR (88.9 mg/dl/1.73 m2, 95% CI for mean 86.4- 91.3) compared to group with normal UACR (93.7 mg/dl/1.73 m2,95% CI 91.1- 96.3) (t 2.7, p 0.007). Three out of the four students with eGFR less than 60 mg/dl/1.73 m2 had moderately elevated UACR.

Conclusion

This study provides evidence to suggest that children in CKDu endemic regions are having an early renal damage. This observation needs to be investigated further in order to understand the worldwide epidemic of CKDu.

Prevalence and associated factors of renal dysfunction and proteinuria in cyanotic congenital heart disease

BACKGROUND

Cyanotic nephropathy (CN), seen in 30-50% of patients with congenital cyanotic heart disease (CCHD), affects both tubular and glomerular function, resulting in proteinuria and azotemia. Microalbuminuria is an early marker for glomerular damage and an independent predictor of progressive renal disease.

METHODS

A cross-sectional study was conducted. A total of 116 patients aged 1 month to 15 years with CCHD at Chiang Mai University Hospital between 2015 and 2016 were assessed and 94 patients were enrolled. To determine the prevalence and associated factors of significant albuminuria in CCHD patients, baseline characteristics, oxygen saturation, surgery, hemoglobin (Hb), hematocrit (Hct), spot urine albumin, urine protein, and creatinine were obtained. Binary logistic-regression modeling was used to identify associated factors.

RESULTS

Prevalence of CN in children with CCHD was 58.51% and 92.55% according to albuminuria and proteinuria staging respectively. Prevalence of significant proteinuria, significant albuminuria, and decreased GFR was 88.30%, 41.49% and 31.91% respectively. Participants with significant albuminuria had fewer previous surgeries (p = 0.05), a longer waiting time for surgery (p = 0.02), enalapril usage (p = 0.04), pulmonary hypertension (p = 0.03), higher Hct z-score (p = 0.03) and lower platelet count (p = 0.001) compared with those without significant albuminuria. Using multivariate logistic regression analysis, waiting duration for surgery (p = 0.04), Hct >40% (p = 0.02), and platelet count <290,000/mm³ (p = 0.04) were predictive of microalbuminuria.

CONCLUSIONS

Cyanotic nephropathy can be detected in the first decade of life with the presentation of microalbuminuria. High Hct level and low platelet count were identified as a predictor of microalbuminuria, whereas early cardiac surgery decreased the risk of developing significant albuminuria.

The population-based prevalence of albuminuria in children

OBJECTIVES

To determine the population-based prevalence of albuminuria in Australian children and validate any negative correlation with body mass index (BMI).

METHODS

Data from the Australian Health Survey 2011-2013 were used. This is a large-scale survey of the health of the Australian population, conducted by the Australian Bureau of Statistics, and uses a stratified, multistage area design with replicate weights attached to observations to allow for the derivation of accurate population estimates. We considered children aged 5-18 years, and defined albuminuria as an albumin-to-creatinine ratio (ACR) >30 mg/g (3.4 mg/mmol).

RESULTS

A total of 975 children provided urine samples for determination of ACR. The prevalence of albuminuria was 10.2% for males (95% confidence interval [CI] 6.1-14.2) and 15.5% for females (95% CI 10.7-20.3). After adjusting for age and gender, the odds ratio for albuminuria associated with being overweight or obese was 0.34 (95% CI 0.15-0.75). This relationship also held for waist-to-height ratio, where the adjusted odds ratio for each 0.1 increase was 0.46 (95% CI 0.26-0.82).

CONCLUSIONS

Albuminuria, using a measurement suitable for population-based and clinical screening, occurs in 12.8% of school-aged Australian children, and is less common in overweight and obese children.

Glomerular barrier behaves as an atomically precise bandpass filter in a sub-nanometre regime

The glomerular filtration barrier is known as a 'size cutoff' slit, which retains nanoparticles or proteins larger than 6-8 nm in the body and rapidly excretes smaller ones through the kidneys. However, in the sub-nanometre size regime, we have found that this barrier behaves as an atomically precise 'bandpass' filter to significantly slow down renal clearance of few-atom gold nanoclusters (AuNCs) with the same surface ligands but different sizes (Au18, Au15 and Au10-11). Compared to Au25 (∼1.0 nm), just few-atom decreases in size result in four- to ninefold reductions in renal clearance efficiency in the early elimination stage, because the smaller AuNCs are more readily trapped by the glomerular glycocalyx than larger ones. This unique in vivo nano-bio interaction in the sub-nanometre regime also slows down the extravasation of sub-nanometre AuNCs from normal blood vessels and enhances their passive targeting to cancerous tissues through an enhanced permeability and retention effect. This discovery highlights the size precision in the body's response to nanoparticles and opens a new pathway to develop nanomedicines for many diseases associated with glycocalyx dysfunction.

Albuminuria, renal function and blood pressure in undernourished children and recovered from undernutrition

BACKGROUND

The objective of this study was to investigate some biomarkers of renal function and blood pressure in children who had recovered from undernutrition.

METHODS

This was cross-sectional, comparative study in which a convenience sample of children of both genders (n = 126; age range 6-16 years) treated at the Centre for Nutritional Recovery and Education (São Paulo, Brazil) was used. These children were classified into four groups for analysis: (1) children who were well nourished (control group; n = 50), (2) those showing stunted growth (stunted group; n = 22), (3) those who were underweight (underweight group; n = 23) and (4) those who had recovered from undernutrition (recovered group; n = 31).

RESULTS

No between-group differences were found for mean levels of albuminuria, serum creatinine and cystatin C, and similar mean estimates of glomerular filtration rate (eGFR; using either creatinine, cystatin C or both). Almost 14% of the stunted group, 4% of the underweight group and 3% of the recovered group had albuminuria of >30 mg/g creatinine (chi-square p = 0.034); none of the control children showed albuminuria of >30 mg/g creatinine. Mean systolic (SBP) and diastolic blood pressure (DBP) adjusted for age and gender of the children in the stunted [SBP (95% confidence interval): 92 (88-96) mmHg; DBP: 47 (44-49) mmHg] and recovered [SBP: 93 (90-96) mmHg; DBP: 49 (47-51) mmHg] groups were significantly lower than those of the controls [SBP: 98 (95-100) mmHg, P = 0.027; DBP: 53 (52-55) mmHg, P = 0.001]. After additional adjustment for height, mean DBP remained significantly lower in the recovered group compared with the control group [49 (46-51) vs. 53 (51-55) mmHg, respectively; P = 0.018). Logistic regression analysis showed that the stunted group had a 8.4-fold higher chance of developing albuminuria (>10 mg/g creatinine) than the control children (P = 0.006).

CONCLUSIONS

No alterations in renal function were found in underweight children and those who had recovered from undernutrition, whereas children with stunted growth presented with a greater risk for albuminuria. A lower DBP was found in children with stunted growth and those who had recovered from undernutrition.

Albuminuria in Pediatric Patients With Adenotonsillar Hypertrophy

The relationship between intermittent nocturnal hypoxia and albuminuria in pediatric patients with adenotonsillar hypertrophy was evaluated in this prospective study. Fifty children with grade 3 to 4 adenotonsillar hypertrophy scheduled for adenoidectomy and/or adenotonsillectomy were selected for study group. Fifteen patients with adenotonsillar grade 1 to 2 or adenotonsillectomized subjects in a similar range of sex, age, and body mass index scheduled for other surgeries were selected for control group. All children were monitored using finger pulse oximeter during the night before surgery. At the day of surgery, first morning urine samples were sent to the laboratory for analysis of albuminuria.Albuminuria was determined in 8 (16%) patients in study group and 1 (6.7%) patient in control group. This difference between groups was determined not to be statistically significant (P > 0.05). None of the pulse oximetry parameters was also found to be associated with albuminuria statistically (P > 0.05). However, the adenoid grade was observed to be associated with albuminuria (P = 0.011).This study revealed no relationship between albuminuria and intermittent hypoxia in children, although previous studies have reported that intermittent hypoxia causes albuminuria in adults. On the contrary, the adenoid grade was found to be in association with albuminuria. The reason seems to be unclear because of the lack of studies investigating albuminuria in children with adenotonsillar hypertrophy. However, inflammatory mediators arising from adenoid tissue may cause increase in renal capillary permeability and urine albumin excretion.

Profiling of Kidney Injury Biomarkers in Patients Receiving Cisplatin: Time-dependent Changes in the Absence of Clinical Nephrotoxicity

The success of cisplatin-containing regimens to treat solid tumors is limited, in part, by nephrotoxicity. In rodents, several urinary proteins have emerged that are sensitive indicators of cisplatin-induced kidney injury. We sought to characterize time-dependent changes in the urinary concentrations of 12 proteins, including kidney injury molecule-1 (KIM-1), calbindin, beta 2-microglobulin (β2M), and trefoil factor 3 (TFF3) after cisplatin therapy. Urine was collected at baseline, 3 days (range, 2-5 days), and 10 days (range, 9-11 days) from 57 patients with solid tumors receiving outpatient cisplatin therapy (≥25 mg/m2 ). Serum creatinine was largely unchanged after cisplatin infusion. However, compared with baseline values, several novel biomarkers were significantly increased in the urine, including β2M, which was threefold higher by day 3 (P < 0.0001). Urinary KIM-1 and TFF3 were elevated twofold by day 10 (P = 0.002 and P = 0.002, respectively), whereas calbindin levels were increased eightfold (P < 0.0001). We report novel time-dependent changes in the urinary excretion of noninvasive markers of subclinical kidney injury after cisplatin treatment.

A functional variant in NEPH3 gene confers high risk of renal failure in primary hematuric glomerulopathies. Evidence for predisposition to microalbuminuria in the general population

Background

Recent data emphasize that thin basement membrane nephropathy (TBMN) should not be viewed as a form of benign familial hematuria since chronic renal failure (CRF) and even end-stage renal disease (ESRD), is a possible development for a subset of patients on long-term follow-up, through the onset of focal and segmental glomerulosclerosis (FSGS). We hypothesize that genetic modifiers may explain this variability of symptoms.

Methods

We looked in silico for potentially deleterious functional SNPs, using very strict criteria, in all the genes significantly expressed in the slit diaphragm (SD). Two variants were genotyped in a cohort of well-studied adult TBMN patients from 19 Greek-Cypriot families, with a homogeneous genetic background. Patients were categorized as “Severe” or “Mild”, based on the presence or not of proteinuria, CRF and ESRD. A larger pooled cohort (HEMATURIA) of 524 patients, including IgA nephropathy patients, was used for verification. Additionally, three large general population cohorts [Framingham Heart Study (FHS), KORAF4 and SAPHIR] were used to investigate if the NEPH3-V353M variant has any renal effect in the general population.

Results and conclusions

Genotyping for two high-scored variants in 103 TBMN adult patients with founder mutations who were classified as mildly or severely affected, pointed to an association with variant NEPH3-V353M (filtrin). This promising result prompted testing in the larger pooled cohort (HEMATURIA), indicating an association of the 353M variant with disease severity under the dominant model (p = 3.0x10^-3, OR = 6.64 adjusting for gender/age; allelic association: p = 4.2x10^-3 adjusting for patients’ kinships). Subsequently, genotyping 6,531 subjects of the Framingham Heart Study (FHS) revealed an association of the homozygous 353M/M genotype with microalbuminuria (p = 1.0x10^-3). Two further general population cohorts, KORAF4 and SAPHIR confirmed the association, and a meta-analysis of all three cohorts (11,258 individuals) was highly significant (p = 1.3x10^-5, OR = 7.46). Functional studies showed that Neph3 homodimerization and Neph3-Nephrin heterodimerization are disturbed by variant 353M. Additionally, 353M was associated with differential activation of the unfolded protein response pathway, when overexpressed in stressed cultured undifferentiated podocyte cells, thus attesting to its functional significance. Genetics and functional studies support a “rare variant-strong effect” role for NEPH3-V353M, by exerting a negative modifier effect on primary glomerular hematuria. Additionally, genetics studies provide evidence for a role in predisposing homozygous subjects of the general population to micro-albuminuria.

Soluble Endoglin Level Increase Occurs Prior to Development of Subclinical Structural Vascular Alterations in Diabetic Adolescents

OBJECTIVE

Soluble endoglin (S-endoglin) has been implicated as a potential marker of endothelial dysfunction (ED) and was reported to be elevated in diabetic adults, correlating with the severity of diabetic vasculopathy. However, circulating S-endoglin and its association with other markers of ED have not been formerly analyzed in the first decade of diabetes onset in adolescents with type 1 diabetes mellitus (T1DM).

METHODS

Fifty-eight adolescents with moderately/poorly controlled T1DM were included in this study and twenty-nine healthy adolescents served as controls. The diabetic group was divided into two groups based on the presence of microalbuminuria, as the microalbuminuria group (n=15) and the normoalbuminuria group (n=43). Functional vascular alterations were evaluated by measuring serum S-endoglin and plasma nitric oxide (NO) concentrations, the flow-mediated dilatation (FMD) of the brachial artery. Carotid intima media thickness (CIMT) was measured for evaluation of structural vascular alterations.

RESULTS

The S-endoglin and NO levels of both microalbuminuria and normoalbuminuria groups were higher than those of the control group (for S-endoglin, p=0.047 and p<0.001; for NO, p=0.004 and p=0.006, respectively). The FMD percent was lower in the microalbuminuria group compared to the normoalbuminuria and control groups (p=0.036 and p=0.020, respectively). There were negative correlations between S-endoglin concentration and FMD percent (r=-0.213, p=0.051) and between serum S-endoglin concentration and albumin excretion rate (r=-0.361, p=0.005). No significant differences were found in CIMT among any of the groups (p=0.443).

CONCLUSION

In adolescents with T1DM, S-endoglin concentrations might increase in parallel to the deterioration in endothelial function before subclinical structural vascular alterations become evident.

Microalbuminuria could improve risk stratification in patients with TIA and minor stroke

Objective

Transient ischemic attacks (TIA) and minor strokes are important risk factors for recurrent strokes. Current stroke risk prediction scores such as ABCD2, although widely used, lack optimal sensitivity and specificity. Elevated urinary albumin excretion predicts cardiovascular disease, stroke, and mortality. We explored the role of microalbuminuria (using albumin creatinine ratio (ACR)) in predicting recurrence risk in patients with TIA and minor stroke.

Methods

Urinary ACR was measured on a spot sample in 150 patients attending a daily stroke clinic with TIA or minor stroke. Patients were followed up at day 7, 30, and 90 to determine recurrent stroke, cardiovascular events, or death. Eligible patients had a carotid ultrasound Doppler investigation. High‐risk patients were defined as those who had an event within 90 days or had >50% internal carotid artery (ICA) stenosis.

Results

Fourteen (9.8%) recurrent events were reported by day 90 including two deaths. Fifteen patients had severe ICA stenosis. In total, 26 patients were identified as high risk. These patients had a higher frequency of previous stroke or hypercholesterolemia compared to low‐risk patients (P = 0.04). ACR was higher in high‐risk patients (3.4 [95% CI 2.2–5.2] vs. 1.7 [1.5–2.1] mg/mmol, P = 0.004), independent of age, sex, blood pressure, diabetes, and previous stroke. An ACR greater than 1.5 mg/mmol predicted high‐risk patients (Cox proportional hazard ratio 3.5 (95% CI 1.3–9.5, P = 0.01).

Interpretation

After TIA or minor stroke, a higher ACR predicted recurrent events and significant ICA stenosis. Incorporation of urinary ACR from a spot sample in the acute setting could improve risk stratification in patients with TIA and minor stroke.

Influence of common genetic variants on childhood kidney outcomes

BACKGROUND

Kidney measures in early life are associated with kidney disease in later life. We hypothesized that these associations are partly explained by common genetic variants that lead to both smaller kidneys with lower kidney function in early childhood and kidney disease in adulthood.

METHODS

We examined in a population-based prospective cohort study among 4,119 children the associations of a weighted genetic risk score combining 20 previously identified common genetic variants related to adult eGFRcreat with kidney outcomes in children aged 6.0 years (95% range 5.7-7.8). Childhood kidney outcomes included combined kidney volume, glomerular filtration rate (eGFR) based on creatinine levels, and microalbuminuria based on albumin and creatinine urine levels.

RESULTS

We observed that the genetic risk score based on variants related to impaired kidney function in adults was associated with a smaller combined kidney volume (P value 3.0 × 10(-3)) and with a lower eGFR (P value 4.0 × 10(-4)) in children. The genetic risk score was not associated with microalbuminuria.

CONCLUSION

Common genetic variants related to impaired kidney function in adults already lead to subclinical changes in childhood kidney outcomes. The well-known associations of kidney measures in early life with kidney disease in later life may at least be partly explained by common genetic variants.

Prevalence and Significance of Unrecognized Renal Dysfunction in Patients with Acute Coronary Syndrome

BACKGROUND

Unrecognized renal insufficiency, defined as estimated glomerular filtration rate <60 mL/min/1.73 m(2) in the presence of normal serum creatinine, is common among patients with acute coronary syndrome. We aimed to determine the prevalence and clinical significance of unrecognized renal insufficiency in a large unselected population of patients with acute coronary syndrome.

METHODS

The study population consisted of patients with acute coronary syndrome included in the Acute Coronary Syndrome Israeli biennial Surveys during 2000-2013. The estimated glomerular filtration rate was calculated using the simplified Modification of Diet in Renal Disease formula. Patients were stratified into 3 groups: 1) normal renal function (estimated glomerular filtration rates ≥60 mL/min/1/73 m(2)); 2) unrecognized renal insufficiency (estimated glomerular filtration rates <60 mL/min/1/73 m(2) with serum creatinine ≤1.2 mg/dL); and 3) recognized renal insufficiency (estimated glomerular filtration rates <60 mL/min/1/73 m(2) with serum creatinine ≥1.2 mg/dL). The primary endpoint was all-cause mortality at 1 year.

RESULTS

Included in the study were 12,830 acute coronary syndrome patients. Unrecognized renal insufficiency was present in 2536 (19.8%). Patients with unrecognized renal insufficiency were older and more frequently females. All-cause mortality rates at 1 year were highest among patients with recognized renal insufficiency, followed by patients with unrecognized renal insufficiency, with the lowest mortality rates observed in patients with normal renal function (19.4%, 9.9%, and 3.3%, respectively, P <.0001). Despite their increased risk, patients with renal insufficiency were less frequently referred for coronary angiography and were less commonly treated with guideline-based cardiovascular medications.

CONCLUSIONS

Acute coronary syndrome patients with unrecognized renal insufficiency should be considered as a high-risk population. The question of whether this group would benefit from a more aggressive therapeutic approach should still be evaluated.