Proteinuria: its clinical importance and role in progressive renal disease

SDS Electrophoresis on Gradient Polyacrylamide Gels as a Semiquantitative Tool for the Evaluation of Proteinuria

Proteinuria is an important sign of kidney diseases. Different protein patterns in urine associated with glomerular, tubular and overload proteinuria may be differentiated using the immunochemical detection of indicator proteins or via urinary proteins electrophoresis. Our aim was to characterize sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) using commercially available 4-20% gradient gels as a method to detect and differentiate proteinuria. Our laboratory-based study used excess urine samples collected for routine diagnostic purposes from adult patients of a tertiary-care hospital, including patients with albumin/creatinine < 30 mg/g and patients with dipstick proteinuria. The limit of albumin detection was estimated to be 3 mg/L. In 93 samples with albumin/creatinine < 30 mg/g, an albumin fraction was detected in 87% of samples with a minimum albumin concentration of 2.11 mg/L. The separation of 300 urine samples of patients with proteinuria revealed distinct protein patterns differentiated using the molecular weights of the detected proteins: glomerular (albumin and higher molecular weights) and two types of tubular proteinuria ("upper" ≥20 kDa and "lower" with lower molecular weights). These patterns were associated with different values of the glomerular filtration rate (median 66, 71 and 31 mL/min/1.72 m², respectively, p = 0.004) and different proportions of multiple myeloma and nephrological diagnoses. As confirmed using tandem mass spectrometry and western blot, the SDS-PAGE protein fractions contained indicator proteins including immunoglobulin G, transferrin (glomerular proteinuria), α1-microglobulin, retinol-binding protein, neutrophil gelatinase-associated lipocalin, cystatin C, and β2-microglobulin (tubular), immunoglobulin light chain, myoglobin, and lysozyme (overflow). SDS-PAGE separation of urine proteins on commercially available 4-20% gradient gels is a reliable technique to diagnose proteinuria and differentiate between its main clinically relevant types.

Clinicopathological Characteristics and Outcomes of Immunoglobulin A Nephropathy with Different Types of Dyslipidemia: A Retrospective Single-Center Study

INTRODUCTION

Immunoglobulin A nephropathy (IgAN) is one of the most common glomerulonephritic diseases in the world. Several lines of evidence have suggested that dyslipidemia is related to the disease progression and prognosis of IgAN. However, the study is scarce on the clinicopathological characteristics and outcomes of IgAN with dyslipidemia.

METHODS

This study retrospectively analyzed 234 patients with biopsy-proven idiopathic IgAN at the Department of Nephrology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, between January 2015 and June 2021. The participants were divided into dyslipidemia (n = 119) and non-dyslipidemia (n = 115), and the dyslipidemia group was also divided into the following 4 groups: hypertriglyceridemia group, hypercholesterolemia group, mixed hyperlipidemia group, and low high-density lipoprotein cholesterol group. The estimated glomerular filtration rate (eGFR) was estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

RESULTS

The prevalence of dyslipidemia in IgAN patients in our center was 50.9% (119/234). The patients with dyslipidemia presented with higher systolic blood pressure (BP), diastolic BP, serum creatinine, uric acid, hemoglobin, proteinuria, and eGFR (p < 0.05). Proportions of males, hypertension, and chronic kidney disease stage 2∼5 were also higher in the dyslipidemia group (p < 0.05). Similarly, the pathological characteristics performed were worse in the dyslipidemia group. Most dyslipidemia patients had a higher percentage of mesangial hypercellularity (M1) and tubular atrophy/interstitial fibrosis (T1∼2) in the Oxford Classification's scoring system (p < 0.05). Multivariate logistic regression analysis revealed that male gender (odds ratio [OR] = 2.397, 95% confidence interval [CI]: 1.051-5.469, p = 0.038) and proteinuria (OR = 1.000, 95% CI: 1.000-1.001, p = 0.035) were possible risk factors for dyslipidemia. A total of 13 patients (13.8%) in the dyslipidemia group had an endpoint event, of which 6 patients (6.4%) had a ≥50% decrease in eGFR from baseline and 7 patients (7.4%) reached the end-stage renal disease stage. Kaplan-Meier survival curve analysis showed that patients in the dyslipidemia group had a worse outcome than those in the non-dyslipidemia group (log-rank test, p = 0.048).

CONCLUSIONS

IgAN patients with dyslipidemia presented more severe clinicopathological characteristics. Male gender and proteinuria are significantly associated with the occurrence of dyslipidemia in IgAN patients. Patients in the dyslipidemia group had a worse prognosis than those in the non-dyslipidemia group, which may be essential for the disease management of IgAN and help identify the high-risk patients.

Chinese Herbal Medicine Suyin Detoxification Granule Inhibits Pyroptosis and Epithelial-Mesenchymal Transition by Downregulating MAVS/NLRP3 to Alleviate Renal Injury

Purpose

Proteinuria is an independent risk factor of chronic kidney disease (CKD). Albumin-induced tubulointerstitial inflammation and epithelial-mesenchymal transition (EMT) via the activation of NLRP3 inflammasome is a potential therapeutic target for CKD. Suyin Detoxification Granule (SDG) improves proteinuria and postpones renal failure. However, the underlying mechanism is still unknown.

Methods

Firstly, the rat model of renal failure was established using intragastric administration of adenine. Renal function, proteinuria, inflammatory indicators in serum, and renal pathology were assessed, and renal immunohistochemical staining of NLRP3 inflammasomes was performed after intervention with low and high concentrations of SDG. Secondly, the model of renal tubular epithelial HK-2 cells was established using albumin in vitro, and the cell viability, EMT phenotype, and the expression of proteins in the NLRP3 inflammasome signaling pathway were measured after the freeze-dried powder of Suyin Detoxification Prescription (SDP) and CY-09, which is a selective and direct NLRP3 inhibitor, were co-incubated with albumin. ATP, SOD, mitochondrial membrane potential, and ROS were further measured in vitro, and changes in the mitochondrial function after SDP intervention were observed. The mitochondrial antiviral signaling protein (MAVS) was knocked down using siRNA, and the interaction between MAVS and NLRP3 was verified using Western blotting, polymerase chain reaction (PCR), and immunofluorescence.

Results

SDG improved renal function and proteinuria, alleviated renal fibrosis, and reduced serum inflammation and the expression of the components of the NLRP3 inflammasome in the kidney. In vitro, SDP and CY-09 enhanced cell viability after injury with albumin and inhibited pyroptosis induced by the NLRP3 inflammatory signaling pathway and expression of proteins involved in EMT. It was further found that SDP alleviated the mitochondrial dysfunction caused by albumin. The knockdown of MAVS reduced the expression of NLRP3 pathway proteins and their mRNA levels and also weakened the co-localization of NLRP3, thus, reducing cell pyroptosis.

Conclusion

SDP protected renal tubular epithelial cells from cell pyroptosis and EMT by regulating the albumin-induced mitochondrial dysfunction/ MAVS/ NLRP3-ASC-caspase-1 inflammasome signaling pathway.

Inhibition of NLRP3 inflammasome ameliorates podocyte damage by suppressing lipid accumulation in diabetic nephropathy

BACKGROUND

Nucleotide leukin-rich polypeptide 3 (NLRP3) inflammasome is documented as a potent target for treating metabolic diseases and inflammatory disorders. Our recent work demonstrated that inhibition of NLRP3 inflammasome activation inhibits renal inflammation and fibrosis in diabetic nephropathy. This study was to investigate the effect of NLRP3 inflammasome on podocyte injury and the underlying mechanism in diabetic nephropathy.

METHODS

In vivo, db/db mice were treated with MCC950, a NLRP3 inflammasome specific inhibitor. NLRP3 knockout (NKO) mice were induced to diabetes by intraperitoneal injections of streptozotocin (STZ). We assessed renal function, albuminuria, podocyte injury and glomerular lipid accumulation in diabetic mice. In vitro, apoptosis, cytoskeleton change, lipid accumulation, NF-κB p65 activation and reactive oxygen species (ROS) generation were evaluated in podocytes interfered with NLRP3 siRNA or MCC950 under high glucose (HG) conditions. In addition, the effect and mechanism of IL-1β on lipid accumulation was explored in podocytes exposed to normal glucose (NG) or HG.

RESULTS

MCC950 treatment improved renal function, attenuated albuminuria, mesangial expansion, podocyte loss, as well as glomerular lipid accumulation in db/db mice. The diabetes-induced podocyte loss and glomerular lipid accumulation were reversed in NLRP3 knockout mice. The increased expression of sterol regulatory element-binding protein1 (SREBP1) and SREBP2, and decreased expression of ATP-binding cassette A1 (ABCA1) in podocytes were reversed by MCC950 treatment or NLRP3 knockout in diabetic mice. In vitro, NLRP3 siRNA or MCC950 treatment markedly inhibited HG-induced apoptosis, cytoskeleton change, lipid accumulation, NF-κB p65 activation, and mitochondrial ROS production in cultured podocytes. In addition, BAY11-7082 or tempol treatment inhibited HG-induced lipid accumulation in podocytes. Moreover, exposure of IL-1β to podocytes induced lipid accumulation, NF-κB p65 activation and mitochondrial ROS generation.

CONCLUSION

Inhibition of NLRP3 inflammasome protects against podocyte damage through suppression of lipid accumulation in diabetic nephropathy. IL-1β/ROS/NF-κB p65 mediates diabetes-associated lipid accumulation in podocytes. The suppression of NLRP3 inflammasome activation may be an effective therapeutic approach to diabetic nephropathy.

Lysosomal dysfunction induced by changes in albumin's tertiary structure: Potential key factor in protein toxicity during diabetic nephropathy

AIMS

Increased amounts of protein, in particular albumin within renal tubular cells (TBCs), induce the expression of inflammatory and fibrogenic mediators, which are adverse prognostic factors in tubulointerstitial fibrosis and diabetic nephropathy (DN). We sought to assess the participation of the thiol-linked tertiary structure of albumin in the mechanism of protein toxicity in a model of TBCs.

MATERIALS AND METHODS

Cultured human renal proximal tubular cells, HK-2, were exposed to isolated albumin from patients with and without DN (Stages 0, 1 and 4). The magnitude of change of the albumin tertiary structure, cell viability (LDH leakage), apoptosis (Annexin V), transdifferentiation and reticulum endoplasmic stress (Western blot and flow cytometry) and lysosomal enzyme activity were assessed.

KEY FINDINGS

We found that albumin from Stage 4 patients presented >50% higher thiol-dependent changes of tertiary structure compared to Stages 0 and 1. Cells incubated with Stage 4 albumin displayed 5 times less viability, accompanied by an increased number of apoptotic cells; evidence of profibrogenic markers E-cadherin and vimentin and higher expression of epithelial-to-mesenchymal transition markers α-SMA and E-cadherin and of endoplasmic reticulum stress protein GRP78 were likewise observed. Moreover, we found that cathepsin B activity in isolated lysosomes showed a significant inhibitory effect on albumin from patients in advanced stages of DN and on albumin that was intentionally modified.

SIGNIFICANCE

Overall, this study showed that thiol-dependent changes in albumin's tertiary structure interfere with the lysosomal proteolysis of renal TBCs, inducing molecular changes associated with interstitial fibrosis and DN progression.

Use of GLP-1 receptor agonists in patients with T2DM and chronic kidney disease

Diabetes mellitus is the leading cause of chronic kidney disease (CKD) in the US. An increasing number of glucagon-like peptide-1 receptor agonists are available for diabetes management. Differences between medications in this class, as well as limited data on patients with CKD, underscore the importance of a patient-centered approach to care.

Association of High Levels of Spot Urine Protein with High Blood Pressure, Mean Arterial Pressure and Pulse Pressure with the Development of Diabetic Chronic Kidney Dysfunction or Failure among Diabetic Patients. Statistical Regression Modeling to Predict Diabetic Proteinuria

INTRODUCTION

In research elevated Blood Pressure (BP) has been demonstrated to be a risk for the development of nephropathy and chronic renal disease (CKD) Or Diabetic Kidney Disease (DKD) among diabetics. However, no study has find correlation for the spot urine protein (UPr) excretion with elevated BP, Pulse Pressure (PP) and mean arterial pressure MAP). This technique was invented in the current study.

METHODS

10,270 were recruited for more than 12 years. Demographically, 43%, 38%, and 16% showed hypertension, nephropathy and chronic renal disease, respectively. UPr demonstrated significant correlations with systolic BP (SBP) and diastolic BP (DPB), MAP and PP (p < 0.0001 for all). SBP, DBP, PP and MAP, UPr were observed to be higher among the groups with nephroaphty and CKD/DKD with highly significant p-values (all p < 0.05). With logistic regression, odds ratio of hypertension (HTN) with nephropathy was observed to be 2.99 (95% CI 2.44 to 3.7; p < 0.0001); and odds ratio of HTN with CKD/DK was 7.1 (95% CI 4.3 to 11.84; p<0.0001), indicating that HTN significantly contributes to the development of nephropathy and CKD/DKD in diabetics.

RESULTS

Invented regression models for the excretion of UPr from the kidney with elevated SBP, DBP, MAP and PP were highly significant (p < 0.0001 for all); UPr = -138.6 + [1.347 × SBP] ; UPr = -93.4 + [1.62 × DBP] ; UPr = -149.5 + [1.922 × MAP] ; UPr = -41.23 +[1.541 × PP].

CONCLUSION

Current study is the first one to introduce this technique. These invented new equations can be used by physicians to estimate protein excretion in urine at bedside and outpatients departments for monitoring proteinuria and CKD/DKD.

Association Between Hypertensive Disorders During Pregnancy and the Subsequent Risk of End-Stage Renal Disease: A Population-Based Follow-Up Study

OBJECTIVE

To assess whether hypertensive disorders during pregnancy (HDPs) are associated with the subsequent development of end-stage renal disease (ESRD).

METHODS

The present study included 1 598 043 women who delivered in Canadian hospitals between April 1993 and March 2003. The baseline information was from the Canadian Institute for Health Information's Discharge Abstract Database. Women with chronic kidney disease, diabetes mellitus, and other specific conditions were excluded. A follow-up study was conducted through a record linkage on their hospitalizations as of the 13th month after the delivery discharge through March 31, 2013. The primary outcome of interest was subsequent hospitalization due to ESRD. Cox model was used to quantify the association between HDPs and ESRD hospitalization.

RESULTS

There occurred 9.9 and 1.7 ESRD hospitalizations per 100 000 person-years in the follow-up of HDPs and non-HDP women, respectively. An increased risk of ESRD hospitalization was observed in pregnant women with pre-eclampsia/eclampsia (adjusted hazard ratio [aHR] = 4.7, 95% CI 3.6-6.0), unspecified HDPs (aHR = 4.6, 95% CI 2.8-7.7), or gestational hypertension (aHR = 3.3, 95% CI 2.1-5.1). Caesarean delivery, preterm delivery, IUGR, and deep vein thrombosis were identified as significant correlates with the subsequent ESRD hospitalization. The risk of subsequent ESRD hospitalization appeared to be lower for women who had ≥2 deliveries compared with those who had one delivery during the study period.

CONCLUSION

Pregnancy complicated with HDPs was significantly associated with an increased risk of ESRD hospitalization in later life, and this association varied by HDP subtype and frequency of delivery.

Urinary protein/creatinine ratio weighted by estimated urinary creatinine improves the accuracy of predicting daily proteinuria

BACKGROUND

The spot urine protein/creatinine ratio (UPCR) is proposed to be a substitute for 24-hour urinary protein (24h-UP). This study is aimed to determine whether the predictive accuracy of 24h-UP using UPCR can be improved by simply multiplying estimated daily urine creatinine excretion (eUCr) and UPCR together.

METHODS

This study enrolled 120 participants to investigate the correlation between spot UPCR and 24h-UP. Three sets of spot urine samples were randomly collected throughout the day and night, along with the first morning void. UPCR was weighted by eUCr to investigate the improvement of accuracy in using spot urine samples to predict 24h-UP.

RESULTS

There were strong correlation and concordance between UPCR and 24h-UP irrespective of the time of spot urine sampling, and the correlation, concordance and agreement were improved after multiplying the UPCR value by the eUCr. Greater improvement was found in the subgroups with measured daily urine creatinine excretion ≤ 0.8 g/d and ≥ 1.2 g/d.

CONCLUSIONS

This investigation demonstrated that multiplying UPCR by eUCr can improve the accuracy of only using UPCR to predict 24h-UP.

Pentoxifylline Attenuates Proteinuria in Anti-Thy1 Glomerulonephritis via Downregulation of Nuclear Factor-κB and Smad2/3 Signaling

Anti-Thy1 glomerulonephritis is a rat nephritis model closely simulating human mesangial proliferative glomerulonephritis. It affects primarily the mesangium, yet displays substantial proteinuria during the course. This study investigated the molecular signals underlying proteinuria in this disease and the modulation of which by the known antiproteinuric agent, pentoxifylline. Male Wistar rats were randomly divided into a control group and nephritic groups with or without treatment with IMD-0354 (an IκB kinase inhibitor), SB431542 (an activin receptor-like kinase inhibitor) or pentoxifylline. Kidney sections were prepared for histological examinations. Glomeruli were isolated for mRNA and protein analysis. Urine samples were collected for protein and nephrin quantitation. One day after nephritis induction, proteinuria developed together with ultrastructural changes of the podocyte and downregulation of podocyte mRNA and protein expression. These were associated with upregulation of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β/activins mRNAs and activation of nuclear factor (NF)-κB p65 and Smad2/3. IMD-0354 attenuated proteinuria on d 1, whereas SB431542 decreased proteinuria on d 3 and 5, in association with partial restoration of downregulated podocyte mRNA and protein expression. Pentoxifylline attenuated proteinuria and nephrinuria through the course, plus inhibition of p-NF-κB p65 (d 1) and p-Smad2/3 (d 5) and partial reversal of downregulated podocyte mRNA and protein. Our data show that the pathogenesis of proteinuria in anti-Thy1 glomerulonephritis involves TNF-α and TGF-β/activin pathways, and the evolution of this process can be attenuated by pentoxifylline via downregulation of NF-κB and Smad signals and restoration of the podocyte component of the glomerular filtration barrier.

Metabolic changes in the urine of andrographolide sodium bisulfite-treated rats

In recent years, andrographolide sodium bisulfite (ASB) has been reported to cause acute renal failure frequently in clinical practice. We hypothesized that changes in metabolic profile could have occurred after administration of ASB. To investigate the metabolic changes caused by ASB-induced nephrotoxicity, metabonomics method was utilized to depict the urine metabolic characteristics and find the specific urine biomarkers associated with ASB-induced nephrotoxicity. Sprague-Dawley rats were randomly assigned into three experimental groups. They received a single daily injection of vehicle (0.9% sodium chloride solution) or ASB at a dose of 100 or 600 mg kg−1 day−1 for 7 days. Twelve-hour urine was collected after the last administration. The routine urinalysis was measured by a urine automatic analyzer while urinary metabolites were evaluated using gas chromatography/mass spectrometry. The acquired data were processed by multivariate principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal PLS-DA. After 7-day administration of ASB, the positive urine samples in protein, occult blood, and ketones were increased, presenting dose dependence. The PCA and PLS-DA models were capable of distinguishing the difference between ASB-treated group and control. Biomarkers such as 1,5-anhydroglucitol, d-erythro-sphingosine, and 2-ketoadipate were identified as the most influential factors in ASB-induced nephrotoxicity.

Fine-tuning of NFκB by glycogen synthase kinase 3β directs the fate of glomerular podocytes upon injury

NFκB is regulated by a myriad of signaling cascades including glycogen synthase kinase (GSK) 3β and plays a Janus role in podocyte injury. In vitro, lipopolysaccharide or adriamycin elicited podocyte injury and cytoskeletal disruption, associated with NFκB activation and induced expression of NFκB target molecules, including pro-survival Bcl-xL and podocytopathic mediators like MCP-1, cathepsin L and B7-1. Broad range inhibition of NFκB diminished the expression of all NFκB target genes, restored cytoskeleton integrity, but potentiated apoptosis. In contrast, blockade of GSK3β by lithium or TDZD-8, mitigated the expression of podocytopathic mediators, ameliorated podocyte injury, but barely affected Bcl-xL expression or sensitized apoptosis. Mechanistically, GSK3β was sufficient and essential for RelA/p65 phosphorylation specifically at serine 467, which specifies the expression of selective NFκB target molecules, including podocytopathic mediators, but not Bcl-xL. In vivo, lithium or TDZD-8 therapy improved podocyte injury and proteinuria in mice treated with lipopolysaccharide or adriamycin, concomitant with suppression of podocytopathic mediators but retained Bcl-xL in glomerulus. Broad range inhibition of NFκB conferred similar but much weakened antiproteinuric and podoprotective effects accompanied with a blunted glomerular expression of Bcl-xL and marked podocyte apoptosis. Thus, the GSK3β dictated fine-tuning of NFκB may serve as a novel therapeutic target for podocytopathy.

Early Predictors of Renal Dysfunction in Egyptian Patients with β-Thalassemia Major and Intermedia

Background

Better survival of thalassemia patients allowed previously unrecognized renal complications to emerge.

Objectives

Assess prevalence and early predictors of renal dysfunction in young β-thalassemia major (β-TM) and intermedia (β-TI) patients.

Subjects

66 β-TM (group I), 26 β-TI (group II) Egyptian patients and 40 healthy controls.

Methods

Clinical assessment and laboratory data including kidney and liver function tests, such as serum ferritin, serum bicarbonate, plasma osmolality and urinary total proteins, microalbuminuria (MAU), N-acetyl-β-D-glucosaminidase (NAG), retinol binding protein (RBP), α-1 microglobulin, bicarbonate, osmolality, creatinine clearance (CrCl), % fractional excretion of bicarbonate (% FE-HCO3).

Results

The prevalent renal abnormality was proteinuria (71%), followed by increased urinary level of RBP (69.4%), NAG (58.1%), α-1 microglobulin (54.8%) and microalbuminuria (29%) and also decreased urinary osmolality (58.1%). CrCl was a better assessment of renal function and significantly lowered in thalassemia patients. Tubular dysfunctions were more significant in splenectomized β-TM patients who showed more elevation of NAG and α-1 microglobulin and lower urinary osmolality. NAG, RBP and α-1 microglobulin were negatively correlated with CrCl and positively correlated with serum ferritin and urinary total protein. Z-score analysis for identifying patients with renal dysfunction proved superiority of urine total protein and RBP. Comparative statistics of different frequencies revealed significant difference between the urinary total protein and both MAU and % FE-HCO3.

Conclusion

Asymptomatic renal dysfunctions are prevalent in young β-TM and β-TI patients that necessitate regular screening. Urinary total protein and RBP may be cost-effective for early detection.

A community-based cross-sectional and longitudinal study uncovered asymptomatic proteinuria in Japanese adults with low body weight

Although proteinuria is highly prevalent in obese individuals, the association between proteinuria and low body weight is equivocal. In this study we determine whether low body weight is more strongly associated with proteinuria compared with normal weight. The association between body mass index (BMI) and proteinuria was examined in a cross-sectional study of 62,582 asymptomatic individuals aged 20-70 years without known kidney diseases recruited, based on the results of medical checkups in 1999. We also examined the incidence of recurrent or nonrecurrent proteinuria in an 8-year longitudinal analysis of 12,493 individuals without proteinuria at baseline. The prevalence of proteinuria showed a J-shaped relationship with BMI. Multivariate regression analysis showed that BMI of 27.0 kg/m(2) and above or 18.9 kg/m(2) and less was significantly associated with proteinuria relative to BMI 21.0-22.9 kg/m(2), even after adjusting for relevant cardiometabolic risk factors. In the longitudinal study, similar J-shaped relationships between the incident rates of proteinuria and baseline BMI groups were observed at post-baseline checkups. Baseline BMI 27.0 kg/m(2) and above was associated with significantly greater risk for recurrent and nonrecurrent proteinuria, whereas BMI 18.9 kg/m(2) and less was only associated with nonrecurrent proteinuria. Thus, obesity and low body weight may be associated with different types of proteinuria independent of cardiometabolic risk factors.

Renal function outcomes in kidney transplant recipients after conversion to everolimus-based immunosuppression regimen with CNI reduction or elimination

BACKGROUND

Chronic allograft nephropathy (CAN) is a major cause of progressive renal failure in kidney transplant recipients. Its etiology is multifactorial and can be due to immunologic or nonimmunologic conditions including calcineurin inhibitor (CNI) toxicity.

OBJECTIVE

To evaluate the effect of conversion from CNIs to everolimus in kidney transplant recipients with CAN.

PATIENTS AND METHODS

In this 12-month pilot study in renal transplant recipients with biopsy-proved CAN, therapy was changed to an everolimus-based immunosuppression regimen. Cyclosporine or tacrolimus dosage was reduced by 80% (group 1, n = 10) or discontinued (group 2, n = 10). Mycophenolate mofetil or azathioprine were withdrawn in group 1, whereas both agents were maintained in group 2. All patients received prednisone.

RESULTS

Twenty renal allograft recipients switched to an everolimus-based regimen, and patients were followed up for a mean (SD) of 12 (0.1) months. Baseline and end-of-study data were as follows: serum creatinine concentration, 1.27 (0.35) mg/dL vs 1.24 (0.4) mg/dL in group 1, and 1.27 mg/dL (0.36) vs 1.25 (0.3) mg/dL in group 2 (difference not significant); and estimated glomerular filtration rate, 72.4 (19.86) mL/min vs 76.26 (22.69) mL/min in group 1 (not significant), and 66.2 (12.95) mL/min vs 66.2 (13.73) mL/min in group 2 (not significant). One patient in group 1 experienced an acute rejection episode (Banff grade Ib), and 2 patients in group 1 and 1 patient in group 2 demonstrated borderline changes, all associated with everolimus blood concentration less than 3 ng/mL.

CONCLUSIONS

Reduction or withdrawal of CNI and introduction of everolimus may be useful to slow the rate of loss of renal function in patients with CAN.

A clinical comparative study of the management of chronic renal failure with Punarnavadi compound

India like any other country is facing a silent epidemic of chronic renal failure (CRF)- a facet of the health transition associated with industrialization partly fuelled by increase in sedentary lifestyle, low birth weight and malnutrition. Increasing figures by many folds seen is posing a difficult situation to overcome with respect to economy and health of the working and earning population of the nation. There is an urgent need to explore, highlight new interventions and modify modifiable risk factors as a basis for treatment strategies to prevent the development and progression of CRF. The present study was taken up to evaluate the role of trial formulation tab. Punarnavadi compound in the management of chronic renal failure. This was an open clinical comparative study in controlled circumstances wherein 67 patients were studied for two months in three groups- Group A (allopathic control), Group B (ayurvedic control) and Group C (ayurvedic test). It was a multi-centric study; patients were registered from Anandababa charitable dialysis centre, Jamnagar, Kayachikitsa O.P.D. of I.P.G.T. and R.A. Jamnagar and P. D. Patel Ayurveda hospital, Nadiad. Results were assessed on 15 parameters using Students (paired) 't' test. Group A patients showed comparatively better results in eight parameters- weight, platelet count, serum urea, serum uric acid, serum sodium, potassium, chloride and total proteins. Parameter Hemoglobin% showed better results in Group B patients and in Group C patients comparatively better results in six parameters viz.- quality of life (breathlessness, weakness, general functional capacity), total count, serum creatinine and serum calcium - were observed. Throughout the study, trial drug tab. Punarnavadi compound did not show any adverse drug reaction. The results of this study will help in developing a cheap and safe treatment for the management of CRF.

C-reactive protein and microalbuminuria in a multi-ethnic Asian population

BACKGROUND

C-reactive protein (CRP), a marker for inflammation, has been recently associated with early kidney damage. We examined the association between CRP and micro/macroalbuminuria in a multi-ethnic Asian population using data from two population-based studies in Singapore. Methods. We studied 5127 individuals, who participated in two separate, cross-sectional studies, the Singapore Prospective Study Program [SP2]/Singapore Cardiovascular Cohort Study 2 (SCCS2), involving 4233 participants of Chinese, Malay and Indian ethnicity, aged 24-95 years in Singapore, and the Singapore Malay Eye Study (SiMES), involving 894 participants of Malay ethnicity, aged 40-80 years. Micro/macroalbuminuria was defined as urinary albumin-to-creatinine ratio of > or =17 mg/g for men and > or =25 g/g for women. CRP was analyzed as a continuous variable and as categories (<1, 1-3, >3 mg/L). Results. The prevalence of micro/macroalbuminuria in the whole population was 21.1%. The prevalence increased with increasing categories of CRP. Compared with persons with CRP concentrations <1 mg/L, the multivariable odds ratio (OR) (95% confidence interval [CI]) was 1.33 (1.11-1.60) in persons with CRP concentrations 1-3 mg/L and 1.60 (1.30-1.96) in persons with CRP concentrations >3 mg/L; P trend <0.0001. In continuous analysis, each unit increase in log CRP was associated with an OR (95% CI) of 1.20 (1.11-1.28) of having micro/macroalbuminuria (P < 0.0001). This association was independent of potential confounders and was consistent across the two study cohorts with similar effect estimates (OR = 1.6) for micro/macroalbuminuria. Conclusions. Elevated CRP levels are associated with micro/macroalbuminuria independent of diabetes, hypertension and other potential confounders. This suggests that inflammation may play a role in early kidney damage.

Dual renin-angiotensin system blockade in the ONTARGET study: clinically relevant risk for the kidney?

Inhibition of the renin-angiotensin system contributes to reductions in proteinuria and in progression of chronic kidney disease. Indeed, monotherapy with either an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB) has been shown to decrease proteinuria and slow the decline of chronic kidney disease, but incompletely. Therefore, there is increasing interest in whether combination strategies will provide more complete blockade of the renin-angiotensin system, which may translate into superior renoprotective and cardioprotective effects compared with either agent alone. There have been several reports on combination strategies. However, the recent report of the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) has received much of the attention. The renal outcomes in ONTARGET suggest that combined ACE inhibitor and ARB therapy contributes to a higher rate of adverse renal outcomes than monotherapy. Therefore, this review explores data from ONTARGET in relation to other available evidence on the use of combination therapies.

Proteinuria >0.5 g/d, a prevalent prognostic factor for patient and graft survival in kidney transplantation

Proteinuria >0.5 g/d (HP) and serum creatinine (Scr) >120 micromol/L (HSC) at three months, two and five yr were compared as prognostic factors in kidney transplantation. We retrospectively analyzed 454 first transplants (follow-up: 100 +/- 3.2 months). Donor/recipient age, sex, panel reactive antibody (PRA), HLA mismatches, cold ischemia time, delayed graft function, acute rejection, blood pressure and its treatment, diabetes and anti-calcineurin use were also evaluated. Cox proportional hazard regression with time-dependent covariates to control for potentially confounding factors was used to analyze survival. The Kaplan-Meier product-limit estimate for survival according to urine protein excretion (< or = or >0.5 g/d) or Scr (< or = or >120 micromol/L) along with the log-rank test for all comparisons were computed. Statistical significance was set with p-value < 0.05.

RESULTS

HSC is a prognostic factor of graft survival (HR: 2.54; 95% CI: 1.98-3.10; p < 0.01) only at five yr, but it does not predict mortality at any period. HP at three months (HR: 2.07; 95% CI: 1.70-2.43; p < 0.001) and at two yr 3.03 (2.54-3.51; p < 0.001) significantly predicts graft failure. HP at two yr is the prevailingly prognostic factor of patient survival in kidney transplantation (HR: 3.30; 95% CI: 1.94-5.62; p < 0.0001).

The use of everolimus in renal-transplant patients

Despite advances in immunosuppressive therapy, long-term renal-transplantation outcomes have not significantly improved over the last decade. The nephrotoxicity of calcineurin inhibitors (CNIs) is an important cause of chronic allograft nephropathy (CAN), the major driver of long-term graft loss. Everolimus is a proliferation signal inhibitor with a mechanism of action that is distinct from CNIs. The efficacy and tolerability of everolimus in renal-transplant recipients have been established in a wide range of clinical trials. Importantly, synergism between everolimus and the CNI cyclosporine (CsA) permits CsA dose reduction, enabling nephrotoxicity to be minimized without compromising efficacy. Currently, everolimus is being investigated in regimens where reduced exposure CNIs are used from the initial post-transplant period to improve renal function and prevent CAN. By inhibiting the proliferation of smooth muscle cells, everolimus may itself delay the progression or development of CAN. Although everolimus is associated with specific side effects, these can generally be managed. By targeting the main causes of short- and long-term graft loss, everolimus has a key role to play in renal transplantation, which is being explored further in a number of ongoing Phase III–IV trials.

Socioeconomic status and microalbuminuria in an Asian population

BACKGROUND

In studies from developed Western countries, lower socioeconomic status (SES) has been reported to be associated with kidney diseases. However, this hypothesis has not been examined in populations from newly industrialized Asian countries. We evaluated the association between SES and micro/macroalbuminuria in a population-based sample in Singapore.

METHODS

We examined 920 participants of Malay ethnicity aged 40-80 years (49.6% female). SES was defined through education, income and housing type of participants. The main outcome of interest was the presence of micro/macroalbuminuria defined as a urinary albumin-to-creatinine ratio (ACR) >or=17 mg/g for men and >or=25 mg/g for women.

RESULTS

Lower categories of SES were associated with micro/macroalbuminuria; compared to the higher categories of SES, the odds ratio (95% confidence interval) of micro/macroalbuminuria was 1.76 (1.23-2.52) for primary/lower education, 1.64 (1.16-2.31) for income <1000 Singapore dollars (SGD)/retired status, 1.44 (1.01-2.06) for small/medium housing type and 2.37 (1.56-3.60) for the coexistence of all three low SES factors (primary/ below education, income <1000 SGD/retired status and small/medium housing type) compared to <or=1 low SES factor. This pattern of association was consistently present in subgroup analyses by gender and age.

CONCLUSIONS

Lower SES is associated with the presence of micro/macroalbuminuria independent of age, gender, smoking, alcohol intake and body mass index among Malay adults in Singapore.

Effect of LDL cholesterol and treatment with losartan on end-stage renal disease in the RENAAL study

Renal pathology and dyslipidemia commonly coexist. Treatments that lower albuminuria/proteinuria may lower lipids, but it is not known whether lipid lowering independent of lessening albuminuria/proteinuria slows progression of kidney disease. We examined the association between LDL cholesterol levels and treatment with losartan on end-stage renal disease (ESRD). Lipid levels and albuminuria measurements were obtained at baseline and at year 1 in a post hoc analysis from the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study, which compared the effects of losartan- versus placebo-based antihypertensive therapy in patients with type 2 diabetes and nephropathy. LDL cholesterol lowering was associated with a lower risk of ESRD; however, this seemed to be largely an association with the reduction in albuminuria.

Hypertensive renal vascular disease and cardiovascular endpoints

PURPOSE OF REVIEW

Hypertension involves the entire cardiovascular system, and hypertensive vascular disease may promote and exacerbate cardiac and renal dysfunction. We discuss the coexistence of cardiorenal disease as a manifestation of vascular involvement in hypertension, and the relationship of biomarkers of renal vascular involvement in hypertension with cardiovascular endpoints.

RECENT FINDINGS

Markers of renal dysfunction, especially microalbuminuria, have been considered recently as potent predictors of cardiovascular morbidity and mortality in all explored populations, including hypertensive individuals. Microalbuminuria, per se, is related to vascular injury and to the increased glomerular permeability of albumin as a direct manifestation of renal vascular involvement in hypertension, a systemic vascular disease. Left ventricular hypertrophy in hypertension develops even before proteinuria or impairment of renal function. Factors including anemia, inflammation and hyperuricemia are either induced or exacerbated by renal vascular disease, and each of these may exert additional influence in determining the increased incidence of cardiovascular events with progressive renal dysfunction.

SUMMARY

The development and progression of vascular disease is the primary determinant in the progressive cardiac and renal dysfunction observed in hypertension and, therefore, is the underlying mechanism of the overall clinical manifestations of cardiorenal disease. Commonly used biomarkers of renal and vascular function are important tools for determination of the progression and, hence, management of hypertensive disease and its complications.

Chronic kidney disease perspectives in Japan and the importance of urinalysis screening

There are racial differences in primary renal diseases for end-stage renal disease (ESRD) and the incidence and prevalence of cardiovascular disease (CVD). To reduce the number of patients with both ESRD and CVD, an effective screening method for CKD should be established. In Japan, screening with the urine dip-stick test for proteinuria has been used since 1972 targeting every child and worker and since 1983 for every resident over 40 years old. There are several reasons for continuing this screening program. First, the positive rate of proteinuria is high in the Japanese general population, especially subjects with neither hypertension nor diabetes. Most of these subjects have no symptoms, and the only sign of renal disease is asymptomatic urinary abnormalities. Second, the prevalence and incidence of glomerulonephritis, especially IgA nephropathy, are high in the Japanese and Asian races, and urinalysis is the only method for early detection of chronic glomerulonephritis. Third, 10-year survival of the ESRD patients due to glomerulonephritis was approximately twice that of ESRD patients due to diabetes and nephrosclerosis. Consequently, reducing the incidence of ESRD due to glomerulonephritis is one of the best ways to reduce the prevalence of ESRD. Furthermore, higher incidence of ESRD in Asian races than in Caucasians was reported. Proteinuria is known to be the best predictor for reducing renal function, and the urine dip-stick test for proteinuria is less expensive and is cost-effective. For an effective screening strategy to reduce the ESRD population in Japanese and Asians, universal screening with the urine dip-stick test for proteinuria could be one solution.

Spot urine protein/creatinine ratios are unreliable estimates of 24 h proteinuria in most systemic lupus erythematosus nephritis flares

The diagnosis of glomerulonephritis flares in systemic lupus erythematosus (SLE) is usually based on whether the magnitude of proteinuria has changed. Our study tests two methods to assess proteinuric change: protein/creatinine (P/C) ratios of intended 24-h urine collections or that of spot urine samples. Sixty-four patients with glomerulonephritis due to SLE followed in the Ohio SLE Study provided bimonthly paired spot and intended 24-h urine collections. Completeness of each collection was estimated as the ratio of the measured creatinine to the expected creatinine based upon Cockroft-Gault. Intended 24-h urine collections with measured/expected creatinine ratios between 0.5 and 0.9 (237 samples overall) showed ratios that were not significantly different from ratios of complete 24-h urine collections with ratios of 0.9-1.1 (159 samples). To compare spot and 24 h P/C ratios, we randomly selected pairs of samples with measured/expected ratios above 0.75. Consistent with previous studies, spot and 24-h urine P/C ratios showed good correlation over the range of values as well as reasonably strong concordance. Over the range of most SLE glomerulonephritis flares, however, correlation was present but concordance was poor. Our work suggests that the use of spot urine P/C ratios will yield more false-positive and -negative diagnoses of glomerulonephritis flares in patients with SLE than the ratio in 24-h urines.

Olmesartan reducing incidence of endstage renal disease in diabetic nephropathy trial (ORIENT): rationale and study design

Diabetic nephropathy (DN) is a leading cause of endstage renal disease (ESRD) in Japan and Hong Kong. Asian patients are known to be more predisposed to DN and ESRD than Caucasians. Strict blood glucose and blood pressure control are key factors in prevention and treatment of DN. In the last decade, inhibition of the renin-angiotensin-aldosterone (RAA) system has been confirmed to reduce the incidence of cardiovascular complications in Caucasian patients with diabetes. Although the RENAAL study has demonstrated the beneficial effects of inhibition of the RAA system on prevention of ESRD and death in type 2 diabetic patients with overt proteinuria, only 17% of patients in this multicenter study were of Asian ethnicity. Given the predilection of Asian diabetic patients for renal complications and the rising burden of ESRD, there is a need to confirm these findings in a homogenous group of Asian patients. The ORIENT (Omesartan Reducing Incidence of Endstage Renal Disease in Diabetic Nephropathy Trial) is a randomized, double-blind, placebo-controlled study in Japan and Hong Kong to evaluate the renal protective benefits of olmesartan medoxomil in type 2 diabetic patients with overt proteinuria (urinary albumin to creatinine ratio > or =300 mg/g creatinine) and renal insufficiency (serum creatinine: 1.0-2.5 mg/dl). The study has a targeted enrollment of 400 Japanese and Hong Kong Chinese patients. The primary outcome is the composite endpoint of time to the first occurrence of doubling of serum creatinine, ESRD (serum creatinine more than 5.0 mg/dl, the need for chronic dialysis, or renal transplantation) or death. The average follow-up period is 4 years and the study ends in 2009.

The confounding issue of comorbid renal insufficiency

The United States is currently beleaguered by twin epidemics, heart failure (HF) and renal insufficiency (RI). HF and RI frequently coexist in the same patient, and this conjunction, often called the "cardiorenal syndrome," has important therapeutic and prognostic implications. Approximately 60% to 80% of patients hospitalized for HF have at least stage III renal dysfunction as defined by the National Kidney Foundation (NKF), and this comorbid RI is associated with significantly increased morbidity and mortality risk. Numerous studies have demonstrated that in patients with HF, indices of renal function are the most powerful independent mortality risk predictors. Comorbid RI can result from both intrinsic renal disease and inadequate renal perfusion. Atherosclerosis, renal vascular disease, diabetes mellitus, and hypertension are significant precursors of both HF and RI. Moreover, diminished renal perfusion is frequently a consequence of the hemodynamic changes associated with HF and its treatment. Both HF and RI stimulate neurohormonal activation, increasing both preload and afterload and reducing cardiac output. Inotropic agents augment this neurohormonal activation. In addition, diuretics can produce hypovolemia and intravenous vasodilators can cause hypotension, further diminishing renal perfusion. Management of these patients requires successfully negotiating the delicate balance between adequate volume reduction and worsening renal function. Despite this, few evidence-based data are available to guide management decisions, indicating a compelling need for additional studies in this patient population.

Relationship Between Clinical Predictors and Tubulointerstitial Damage in Adult-onset Primary Nephrotic Syndrome

BACKGROUND

Tubulointerstitial damage (TID) is an important mediator in the progression of chronic proteinuric nephropathies. Our aim in this study was to evaluate the relationship between several clinical predictors and TID in adult-onset primary nephrotic syndrome in China.

METHODS

One hundred ninety-five adult inpatients who were diagnosed with primary nephrotic syndrome based on clinical presentation and biopsy results were enrolled in this study from March 2003 to September 2005. The degree of TID was graded by a semiquantitative method including <2 score and >or=2 score.

RESULTS

In all patients, the rate of glomerulosclerosis was correlated with the severity of TID. Serum creatinine and uric acid (r = 0.183, p = 0.012 and r = 0.377, p = 0.00001, respectively) but not serum lipid or total 24-h urinary protein were related with TID. In 64 patients, urinary excretion of IgG (r = 0.443, p = 0.00001) but not of albumin, transferrin, retinal-binding protein, or alpha1-microglobulin were significantly associated with the extent of TID. Proteinuria selectivity index based upon IgG also correlated significantly with the extent of TID (p = 0.0001) (score 0-1 vs. score >or=2).

CONCLUSIONS

These results showed that serum creatinine and uric acid, the excretion of urinary IgG and proteinuria selectivity index based upon IgG, were highly correlated with the severity of TID in adult-onset primary nephrotic syndrome. These clinical parameters might be useful for predicting the development and progression of proteinuric nephropathy as independent risk factors.

Renal and vascular function in women with previous preeclampsia: A comparison of low- and high-degree proteinuria

The degree of proteinuria during preeclampsia has been considered to be a marker of severity of the disease and of endothelial dysfunction. The aim of the study was to assess whether the degree of proteinuria in preeclamptic pregnancy is related to impairment of vascular dilatation and/or kidney function years after the index pregnancy. Thirty women with a history of severe preeclampsia divided into low (n=8, dU-prot <5 g/day) and high (n=22, dU-prot >/=5 g/day) proteinuric groups and 21 women with previous normotensive pregnancy were studied 5-6 years after index pregnancy. Renal function and blood pressure were assessed together with venous occlusion plethysmography, where changes in brachial artery blood flow, induced by intra-arterial infusions of an endothelium-independent (sodium nitroprusside) and an endothelium-dependent (acetylcholine) vasodilator, were measured. The results showed similar renal function in all groups. There was no difference in vasodilation between preeclamptic groups and controls or correlation between degree of proteinuria during index pregnancy and present vasodilation. We conclude that the degree of proteinuria during preeclampsia does not predict vascular dilatation or renal function 5-6 years after preeclamptic pregnancy.

Viral hepatitis and proteinuria in an area endemic for hepatitis B and C infections: another chain of link?

BACKGROUND AND OBJECTIVES

Virus hepatitis may lead to nephropathy as one of its multiple extrahepatic manifestations. Proteinuria by dipstick, a simple test in practice, is a useful and cardinal sign of underlying renal abnormalities. The aim of this study was to elucidate the impact of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections on the occurrence of proteinuria amongst adults.

DESIGN AND SETTING

A prospective, cross-sectional, community-based study was conducted in an HBV/HCV endemic area of southern Taiwan. Eligible subjects aged 40-65 years (n=9934) underwent testing of hepatitis B surface antigen (HBsAg), HCV antibody (anti-HCV) and other related biochemical profiles. Urinalysis with repeated dipstick for proteinuria detection was performed.

RESULTS

Anti-HCV-positive rate amongst proteinuria subjects was significantly higher than nonproteinuria subjects (9.6% vs. 6.2%, P<0.001). By contrast, HBsAg-positive rate did not differ between subjects with and without proteinuria (13.0% vs. 13.8%, P=0.57). Prevalence of proteinuria amongst anti-HCV-positive subjects (10.2%) was significantly higher than that in HBsAg-positive subjects (6.4%, P=0.004) and in HBsAg-negative or anti-HCV-negative subjects (7.0%, P=0.004). The difference persisted even after excluding diabetics. Multivariate logistic regression analyses showed that diabetes was the most important significant factor associated with proteinuria, followed by hypertension, anti-HCV seropositivity, body mass index, age and triglyceride levels.

CONCLUSION

We demonstrated the significant association between proteinuria and HCV, but not HBV, infection in this HBV/HCV-endemic area.

[Proteinuria]

Several health organizations recommend that people be regularly checked for proteinuria to detect and treat kidney disease before it progresses. Proteinuria detected by a simple dipstick test should be confirmed by a quantitative measurement to assess persistent proteinuria. Most proteins are too big to pass through the kidneys' filters into the urine unless the kidneys are damaged. Markers of kidney damage in addition to proteinuria include abnormalities in the urine sediment, ultrasound of the kidneys and estimation of kidney function (creatinemia to calculate glomerular filtration rate). These assessments provide clues to the type (diagnosis) of chronic kidney disease and will the risk for developing progressive kidney failure. Thus, early detection of kidney disease will result in a more timely introduction of therapy that may slow the course of kidney disease. Microalbuminuria (albumin excretion above the normal range) that a marker of microvascular lesions in diabetes and hypertension is associated with a worth cardiovascular prognosis. Level of proteinuria in excess of 3,0 g/d in glomerular disease strongly determines the extent of kidney damage and renal prognosis.

Pentoxifylline ameliorates proteinuria through suppression of renal monocyte chemoattractant protein-1 in patients with proteinuric primary glomerular diseases

Proteinuria (albuminuria) reflects dysfunction of the glomerular permeability barrier in which inflammatory cytokines play a key role. Pentoxifylline (PTX) is a phosphodiesterase inhibitor that possesses potent anti-inflammatory and immunomudulatory effects. This study evaluated the effectiveness of PTX to reduce proteinuria and inflammatory mediators in patients with proteinuric primary glomerular diseases. Seventeen patients with primary glomerular diseases, a persistent spot proteinuria exceeding 1.5 g/g creatinine (Cr) and a glomerular filtration rate between 24 and 115 ml/min/1.73 m(2) were treated with PTX 400 mg twice daily for 6 months. Before and after the treatment, serum Cr, plasma renin activity and aldosterone concentrations, plasma and urinary tumor necrosis factor (TNF)-alpha, interleukin-1beta and monocyte chemoattractant protein (MCP)-1, as well as urinary protein and Cr were measured. PTX significantly reduced urinary protein excretion, along with an increase of serum albumin. A significant correlation existed between the basal urinary protein/Cr and the basal urinary MCP-1/Cr ratios. PTX lowered the urinary MCP-1/Cr ratio, and the percent reduction of urinary protein/Cr ratio correlated directly with the precent decrease of urinary MCP-1/Cr ratio after PTX treatment. There was no significant change in blood pressure, renal function, biochemical parameters, plasma renin activity and aldosterone concentrations, or plasma TNF-alpha and MCP-1 levels during the study. In conclusion, administration of PTX 800 mg per day is safe and effective for reducing proteinuria in patients with proteinuric primary glomerular diseases. This beneficial effect occurs in close association with a reduction of urinary MCP-1 excretion.

The association of poverty with the prevalence of albuminuria: data from the Third National Health and Nutrition Examination Survey (NHANES III)

BACKGROUND

Albuminuria is a major risk factor for the development and progression of chronic kidney disease (CKD) and cardiovascular disease. Socioeconomic factors also have been reported to modify CKD and cardiovascular risk factors and clinical outcomes. The extent to which poverty influences the prevalence of albuminuria, particularly among racial/ethnic minority populations, is not well established. The influence of poverty on the prevalence of albuminuria and the implication of this relationship for the racial and/or ethnic differences in the prevalence of albuminuria were examined.

METHODS

We examined data from 6,850 male and 7,634 female adults from a national probability survey conducted between 1988 and 1994.

RESULTS

In univariate analysis, poverty, defined as less than 200% federal poverty level (FPL), was associated with the presence of both microalbuminuria (odds ratio [OR], 1.35; 95% confidence interval, 1.22 to 1.49) and macroalbuminuria (OR, 1.78; 95% confidence interval, 1.40 to 2.26). The association of less than 200% FPL with microalbuminuria persisted in a multivariate model controlling for age, sex, race, education, obesity, hypertension, diabetes, reduced glomerular filtration rate, and medication use (OR, 1.18; 95% confidence interval, 1.05 to 1.33). FPL less than 200% was not associated with macroalbuminuria in the multivariate model. When multivariate analysis is stratified by FPL (<200% and > or =200%), differences in ORs for microalbuminuria and macroalbuminuria among racial/ethnic minority participants compared with whites were more apparent among the less affluent participants in the FPL-less-than-200% stratum.

CONCLUSION

FPL less than 200% is associated with microalbuminuria, and differences in FPL levels may account for some of the observed differences in prevalence of albuminuria between racial/ethnic minority participants and their white counterparts.

Management of the cardiorenal syndrome in heart failure

Heart failure treatment has seen great improvements in the past few decades. In many cases of heart failure, coexisting renal dysfunction, known as the cardiorenal syndrome, complicates treatment. Renal dysfunction is known to be a predictor of increased mortality. Renal dysfunction can be caused by various hemodynamic forces, medications, and intrinsic renal disease. With an understanding of the underlying etiology and physiology of the renal dysfunction, the appropriate treatment strategy can be planned. This understanding can also indicate when it is necessary to resort to therapies such as left ventricular assist device or dialysis. Such targeting of therapy can improve the prognosis of patients with heart failure and renal dysfunction.

Adverse perinatal outcome and later kidney biopsy in the mother

Strong associations of adverse perinatal outcomes have been identified with later cardiovascular disease in the mother. Few studies have addressed associations with kidney disease. This study investigated whether perinatal outcomes are associated with later clinical kidney disease as diagnosed by kidney biopsy. The Medical Birth Registry of Norway contains data on all childbirths in Norway since 1967. The Norwegian Kidney Biopsy Registry contains data on all kidney biopsies in Norway since 1988. All women with a first singleton delivery from 1967 to 1998 were included. Pregnancy-related predictors of later kidney biopsy were analyzed by Cox regression analyses. A total of 756,420 women were included, and after a mean period of 15.9+/-9.4 yr, 588 had a kidney biopsy. Compared with women without preeclampsia and with offspring with birth weight of >or=2.5 kg, women with no preeclampsia and with offspring with birth weight of 1.5 to 2.5 kg had a relative risk (RR) for a later kidney biopsy of 1.7, women with no preeclampsia and with offspring with birth weight of <1.5 kg had an RR of 2.9, women with preeclampsia and with offspring with a birth weight of >or=2.5 kg had an RR of 2.5, women with preeclampsia and with offspring with a birth weight of 1.5 to 2.5 kg had an RR of 4.5, and women with preeclampsia and with offspring with a birth weight of <1.5 kg had an RR of 17. Similar results were found in adjusted analyses and after exclusion of women with diabetes, kidney disease, or rheumatic disease before pregnancy. The same risk patterns applied to any of the specific categories of kidney disease as well as specific kidney diseases investigated. Women who have preeclampsia and give birth to offspring with low birth weight and short gestation have a substantially increased risk for having a later kidney biopsy.

Kidney disease and cardiovascular disease: implications of dyslipidemia

Cardiovascular complications are common inpatients with kidney disease. Regulating the lipid levels in these patients is important so that the risks of kidney and cardiovascular complications can be minimized. Lipid regulation decreases the incidence of coronary vascular events and other vascular complications in patients with kidney disease; however, whether lipid regulation slows progression of kidney disease is not yet known. Additional studies of the implications of dyslipidemia in patients with kidney disease are needed.

Managing the Failing Allograft

Managing the failing allograft juxtaposes immunosuppressive management and routine chronic kidney disease care. The complications of immunosuppression can be more pronounced in those with renal failure (infection, anemia, bone disease). The withdrawal of immunosuppression may be associated with acute allograft rejection, arthralgias, and the development of antidonor antibodies. Likewise depression is prevalent. Improving well-being and overall survival necessitates proper titration of immunosuppressive medications and control of blood pressure, anemia, lipids, and glucose along with attention to treatment of depression.