Serum cystatin C as a predictor for cardiovascular events in end-stage renal disease patients at the initiation of dialysis

BACKGROUND

There has been no study to investigate whether cystatin C could predict cardiovascular events in incident dialysis patients. We aimed to delineate the role of serum cystatin C and cystatin C-based estimated glomerular filtration rate (eGFR(cysC)) for prediction of cardiovascular events.

METHODS

This study included 66 end-stage renal disease patients who survived for >3 months after the start of dialysis, and serum cystain C levels were measured at the point of dialysis initiation.

RESULTS

Serum cystatin C was correlated with blood urea nitrogen (r = 0.537, p < 0.001), serum creatinine (r = 0.480, p < 0.001) and smoking (r = 0.284, p = 0.021). Cystatin C was inversely correlated with age (r = -0.316, p = 0.01) and eGFR(Cr) by modification of diet in renal disease (r = -0.533, p < 0.001). Kaplan-Meier analysis for cardiovascular events revealed that patients in the group with lower cystatin C levels (<4.14 mg/L) had a better event-free survival rate than patients in the group with higher cystatin C levels (≥4.14 mg/L) (p = 0.039). In univariate analysis, cystatin C (hazard ratio (HR) 2.62, p = 0.011) and eGFR(cysC) (HR 0.64, p = 0.004) were significant factors for the prediction of cardiovascular events. After multivariate adjustment, serum cystatin C and eGFR(cysC) were independent determinants of cardiovascular events (HR 3.952, p = 0.001 and HR 0.640, p = 0.004, respectively).

CONCLUSION

Serum cystatin C might be an independent marker of cardiovascular events in incident dialysis patients. Furthermore, eGFR(cysC) based on measured serum cystatin C could have a new role in predicting cardiovascular events beyond the estimation of true GFR.

Imbalance of regulatory T cells to Th17 cells in IgA nephropathy

BACKGROUND

Dysregulation of CD4 (+) T cell subsets participates in the pathogenesis of IgA nephropathy (IgAN). FoxP3 (+) regulatory T cells (Treg) and Th17 cells are two novel subsets of CD4 (+) T cells. This study aims to investigate Treg/Th17 balance in IgAN patients.

METHODS

Peripheral frequencies of Th17 and Treg functional subsets - CD45RA (+) FoxP3(low) resting Treg (rTreg) and CD45RA(-)FoxP3(high) activated Treg (aTreg) were assessed in 63 adult IgAN patients. Expression of transcription factors (FoxP3 and RORγt) and related cytokines of Treg and Th17 were analysed. Renal expression of FoxP3 and IL-17A were detected by immunohistochemistry.

RESULTS

Compared with normal controls, IgAN patients had decreased frequency of CD45RA(-)FoxP3(high) aTreg subset (p < 0.05), increased frequency of Th17 (p < 0.05) and decreased ratio of Treg/Th17 (p < 0.05). Frequency of aTreg subset correlated with SBP(r = - 0.57, p < 0.05), DBP (r = - 0.50, p < 0.05), eGFR (r = 0.68, p < 0.05) and 24 h proteinuria (r = - 0.58, p < 0.05). RORγtmRNA/FoxP3mRNA ratio increased in IgAN (p < 0.05). Serum IL-17A, IL-21, IL-23, IL-1β and IL-6 elevated while IL-10 decreased in IgAN (p < 0.05), and serum IL-17A correlated with 24 h proteinuria (r = 0.35, p < 0.05). Serum TGF-β1 wasn't different between the two groups. Renal interstitial infiltration of FoxP3 (+) mononuclear cells were observed in IgAN patients, particularly prominent in those with > 25% tubular atrophy/interstitial fibrosis. Tubular IL-17A expression was found in 34 out of 63 IgAN patients. Compared with 29 patients without IL-17A expression, these patients had lower renal function, greater proteinuria, and more severe tubulointerstitial damage.

CONCLUSIONS

Imbalance of Treg/Th17 found in IgAN may play a role in disease pathogenesis and progression.

Analysis of early kidney damage in hospitalized patients with chronic kidney disease: a multicenter study

BACKGROUND

To identify the risk factors for early kidney damage in hospitalized Chinese patients with chronic kidney disease (CKD).

METHODS

A total of 12 multicenter cross-sectional studies were conducted between January 2005 and January 2006 in Chinese CKD patients with estimated glomerular filtration rate (eGFR) equal to or more than 30 mL/min/1.73 m2 in Shanghai. CKD was defined according to the K/DOQI guideline. GFR was estimated by the simplified modification of diet in renal disease equation. The demographic, clinical, and laboratory data were collected through a questionnaire and analyzed among eligible patients stratified by three different CKD groups (CKD stages 1, 2, and 3). The relevant clinical and laboratory risk factors for early kidney damage with a GFR < 90 mL/min/1.73 m2 were determined by logistic regression.

RESULTS

A total of 822 CKD patients were enrolled in this study. There were significant differences in age and gender among patients with CKD stages 1, 2, and 3. The prevalence of hypertension, cardiovascular disease, cerebral vascular disease, anemia, and hyperuricemia increases when the eGFR declines. Logistic analysis showed that age, hypertension, anemia, and hyperuricemia were independently associated with early kidney damage.

CONCLUSIONS

In CKD patients, we have identified only age, hypertension, anemia, and hyperuricemia as the risk factors for early kidney damage. Risk factors should be managed to prevent accelerated kidney damage in CKD patients.

Impact of elevated serum glycated albumin levels on contrast-induced acute kidney injury in diabetic patients with moderate to severe renal insufficiency undergoing coronary angiography

BACKGROUND

Glycated albumin (GA) has been shown to be a better indicator than glycosylated hemoglobin A1c (HbA1c) in terms of severity of renal impairment in patients with type 2 diabetes mellitus (T2DM). This study aimed to determine whether elevated serum GA levels are associated with an increased risk for contrast-induced acute kidney injury (CI-AKI) and worse clinical outcome in patients with T2DM and at least moderate renal insufficiency (RI) undergoing coronary angiography.

METHODS

Serum levels of fasting blood glucose (FBG), HbA1c and GA were measured in 1030 patients with T2DM and moderate to severe RI (eGFR 15-59 mL/min/1.73 m(2)). CI-AKI was defined as ≥ 25% increase in serum creatinine within 72 h after the procedure. Receiver-operating characteristic curve was constructed to assess the predictive value of GA, HbA1c and FBG for CI-AKI. Multivariable logistic regression model was developed to identify risk factors for CI-AKI, and Kaplan-Meier curve analysis was used to compare the rates of dialysis and major adverse cardiac events (MACE) during one-year follow-up.

RESULTS

The overall rate of CI-AKI was 11.1%. GA was significantly higher in patients with CI-AKI than in those without, and correlated positively with changes of renal function after the procedure. After adjusting for age, sex, left ventricular ejection fraction, multi-vessel disease, type and volume of contrast media, FBG, and HbA1c, GA remained an independent risk factor for CI-AKI. GA ≥ 21% was associated with increased rates of dialysis and MACE during one-year follow-up in patients with or without CI-AKI.

CONCLUSIONS

Increased GA level serves as a valuable risk factor for CI-AKI and indicates poor one-year clinical outcome in patients with T2DM and moderate to severe RI.

The impact of different GFR estimating equations on the prevalence of CKD and risk groups in a Southeast Asian cohort using the new KDIGO guidelines

Background

Recently, the Kidney Disease: Improving Global Outcomes (KDIGO) group recommended that patients with CKD should be assigned to stages and composite relative risk groups according to GFR (G) and proteinuria (A) criteria. Asians have among the highest rates of ESRD in the world, but establishing the prevalence and prognosis CKD is a problem for Asian populations since there is no consensus on the best GFR estimating (eGFR) equation. We studied the effects of the choice of new Asian and Caucasian eGFR equations on CKD prevalence, stage distribution, and risk categorization using the new KDIGO classification.

Methods

The prevalence of CKD and composite relative risk groups defined by eGFR from with Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI); standard (S) or Chinese(C) MDRD; Japanese CKD-EPI (J-EPI), Thai GFR (T-GFR) equations were compared in a Thai cohort (n = 5526)

Results

There was a 7 fold difference in CKD_3-5 prevalence between J-EPI and the other Asian eGFR formulae. CKD_3-5 prevalence with S-MDRD and CKD-EPI were 2 - 3 folds higher than T-GFR or C-MDRD. The concordance with CKD-EPI to diagnose CKD_3-5 was over 90% for T-GFR or C-MDRD, but they only assigned the same CKD stage in 50% of the time. The choice of equation also caused large variations in each composite risk groups especially those with mildly increased risks. Different equations can lead to a reversal of male: female ratios. The variability of different equations is most apparent in older subjects. Stage G3aA1 increased with age and accounted for a large proportion of the differences in CKD_3-5 between CKD-EPI, S-MDRD and C-MDRD.

Conclusions

CKD prevalence, sex ratios, and KDIGO composite risk groupings varied widely depending on the equation used. More studies are needed to define the best equation for Asian populations.

Estimating glomerular filtration rates by use of both cystatin C and standardized serum creatinine avoids ethnicity coefficients in Asian patients with chronic kidney disease

BACKGROUND

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is most accurate for estimating glomerular filtration rate (GFR) but requires an adjustment for African-American patients. Estimation equations are also improved with the use of serum cystatin C combined with standardized creatinine. Combination equations have been derived by the CKD-EPI and Chinese investigators. We investigated whether these cystatin C-based equations improve estimation adequately, so that adjustments for ethnicity are not required in a multiethnic Asian population with chronic kidney disease (CKD).

METHODS

This was a cross-sectional study of 232 stable CKD patients who underwent GFR measurements using 3-sample plasma clearances of (99m)Tc-DTPA, and for whom serum cystatin C and creatinine were quantified.

RESULTS

For all patients, the median biases with cystatin C equations were generally greater than with the CKD-EPI equation, and precision and root mean square error (RMSE) were not significantly better. However, the combination serum creatinine and cystatin C equation improved the precision, RMSE, and percentage of estimated GFR to within 15% and 30% of the measured GFR (57.3% vs 50.0%, 88.4% vs 82.8%, respectively). The derived ethnicity coefficients for the combination equation were all >1 (1.009-1.082) but small, suggesting that coefficients are not required. The Chinese-specific equations were more biased and performed more poorly than the CKD-EPI equation.

CONCLUSIONS

The use of a cystatin C and creatinine combination equation for estimating GFR in a multiethnic Asian population with CKD does not require ethnicity coefficients because the derived coefficients are very close to each other.

Frequency of established cardiovascular disease and its risk factors in Chinese patients with systemic lupus erythematosus

Cardiovascular disease (CVD) is one of the most serious complications of systemic lupus erythematosus (SLE). This study investigated the frequency of established CVD and its associated risk factors in Chinese patients with SLE. A retrospective, cross-sectional analysis was conducted of 1,072 consecutive patients with SLE from a single center. Patients with CVD were identified on the basis of medical record documentation. Stepwise multivariate logistic regression was used to assess the risk factors of CVD. Of the 1,072 patients with SLE, 71 (6.6%) had CVD. Patients with CVD were older than patients without CVD (39.0 ± 15.6 vs. 31.9 ± 13.3 years; P < 0.001), the frequency of CVD in patients aged ≤19 years, between 20 and 39 years, between 40 and 69 years, and greater than 60 years was increased by 3.4%, 5.5%, 9.2%, 20.4%, respectively. The frequency of CVD was higher in SLE patients with nephritis than without nephritis (7.6% vs. 3.8%; P = 0.026). Multivariate regression analyses confirmed that age ≥60 years (OR = 5.098; 95% CI 1.333, 19.488), higher diastolic blood pressure (OR = 1.050; 95% CI 1.022, 1.078), higher serum creatinine levels (OR = 1.002; 95% CI 1.000, 1.003), and long-term use of glucocorticoids (OR = 1.005; 95% CI 1.000, 1.010) were risk factors for CVD. HDL-C levels (OR = 0.121; 95% CI 0.041, 0.358) were negatively associated with CVD in patients with SLE. Our data suggest that the frequency of CVD was high in Chinese patients with SLE, and independent risk factors for CVD were increased age, higher diastolic blood pressure, higher serum creatinine levels, long-term use of glucocorticoids, and lower HDL-C levels.

Effect of HBV polymerase inhibitors on renal function in patients with chronic hepatitis B

BACKGROUND & AIMS

Therapy of chronic hepatitis B with HBV-polymerase inhibitors, in particular tenofovir or adefovir, may affect renal function. To assess renal function more accurately in the normal range, we used the recently validated, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula to calculate the estimated glomerular filtration rate (eGFR).

METHODS

Patient subgroups included: patients with HBV-monoinfection treated with lamivudine (n=36), adefovir (n=32), entecavir (n=32), or tenofovir (n=37). HBsAg-positive untreated patients (n=60) served as control. For comparison HIV-monoinfected patients treated with tenofovir (n=120) or zidovudine (n=52) based antiretroviral therapy and antiretroviral naive patients (n=109) were assessed. CKD-EPI equation was used to calculate eGFR. In a more sensitive approach, we modeled the individual change in eGFR over time with linear mixed effects models (LME).

RESULTS

Yearly predicted median changes in individual eGFR according to the LME model were: HBV untreated -2.05 ml/min, HBV lamivudine -0.92 ml/min, HBV adefovir -1.02 ml/min, HBV entecavir -1.00 ml/min, and HBV tenofovir -0.92 ml/min (p<0.01 for HBV untreated vs. HBV treated). In HIV-monoinfected patients: HIV untreated -0.62 ml/min, HIV treated with tenofovir -2.64 ml/min, HIV treated with zidovudine -1.0 ml/min (p=0.017 for tenofovir vs. no treatment, p<0.001 for tenofovir vs. zidovudine).

CONCLUSIONS

Therapy of HBV infection irrespective of medication seems to result in a milder decrease of renal function. In contrast tenofovir as part of HIV combination therapy seems to impair renal function in this Caucasian population.

Top Three Pharmacogenomics and Personalized Medicine Applications at the Nexus of Renal Pathophysiology and Cardiovascular Medicine

Pharmacogenomics is a field with origins in the study of monogenic variations in drug metabolism in the 1950s. Perhaps because of these historical underpinnings, there has been an intensive investigation of 'hepatic pharmacogenes' such as CYP450s and liver drug metabolism using pharmacogenomics approaches over the past five decades. Surprisingly, kidney pathophysiology, attendant diseases and treatment outcomes have been vastly under-studied and under-theorized despite their central importance in maintenance of health, susceptibility to disease and rational personalized therapeutics. Indeed, chronic kidney disease (CKD) represents an increasing public health burden worldwide, both in developed and developing countries. Patients with CKD suffer from high cardiovascular morbidity and mortality, which is mainly attributable to cardiovascular events before reaching end-stage renal disease. In this paper, we focus our analyses on renal function before end-stage renal disease, as seen through the lens of pharmacogenomics and human genomic variation. We herein synthesize the recent evidence linking selected Very Important Pharmacogenes (VIP) to renal function, blood pressure and salt-sensitivity in humans, and ways in which these insights might inform rational personalized therapeutics. Notably, we highlight and present the rationale for three applications that we consider as important and actionable therapeutic and preventive focus areas in renal pharmacogenomics: 1) ACE inhibitors, as a confirmed application, 2) VDR agonists, as a promising application, and 3) moderate dietary salt intake, as a suggested novel application. Additionally, we emphasize the putative contributions of gene-environment interactions, discuss the implications of these findings to treat and prevent hypertension and CKD. Finally, we conclude with a strategic agenda and vision required to accelerate advances in this under-studied field of renal pharmacogenomics with vast significance for global public health.

Glomerular filtration rate estimation in patients with type 2 diabetes: creatinine- or cystatin C-based equations?

AIMS/HYPOTHESIS

It is argued that GFR estimation (eGFR) using cystatin C-based equations (eGFRcys) is superior to that using creatinine-based equations (eGFRcre). We investigated whether eGFRcys are superior to eGFRcre in patients with type 2 diabetes.

METHODS

GFR was measured in 448 type 2 diabetic patients using (51)Cr-EDTA-measured GFR (mGFR) as the reference standard. Bias, precision and accuracy of eGFRcys and eGFRcre were compared.

RESULTS

The most accurate eGFRcre equation (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), which produced the highest proportion of estimates that were within 30% and 10% of the reference standard (80.7% and 38.0% of samples, respectively) had a bias of 7.1 and precision of 12.0 ml min(-1) 1.73 m(-2). The calibrated eGFRcys with the highest accuracy (Tan-C), which produced the highest proportion of estimates that were within 30% (78.8%) and within 10% (39.0%) of the reference standard had a bias of -3.5 and precision of 18.0 ml min(-1) 1.73 m(-2). Moreover, the areas under the receiver operating curve were higher with eGFRcre (CKD-EPI and Modification of Diet in Renal Disease [MDRD]) than with eGFRcys for the diagnosis of mild (mGFR <90 ml min(-1) 1.73 m(-2)) and moderate (mGFR <60 ml min(-1) 1.73 m(-2)) chronic kidney disease. In patients with mGFR ≥90 ml min(-1) 1.73 m(-2), CKD-EPI was the least biased, the most precise and the most accurate equation.

CONCLUSIONS/INTERPRETATION

In patients with type 2 diabetes, eGFRcys do not currently provide better eGFR than eGFRcre. At present, compared with eGFRcys, eGFRcre are better at predicting the stage of chronic kidney disease. In addition, CKD-EPI seems to be the best equation for eGFR in patients with normal renal function.

Re-evaluation of the histopathologic classification of ANCA-associated glomerulonephritis: a study of 121 patients in a single center

BACKGROUND

The recently published histopathologic classification of antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis might greatly aid in the prognostication of patients at the time of diagnosis. This study aims to re-evaluate the new classification for its prognostic capacity in an independent Chinese series.

METHODS

One hundred and twenty-one consecutive patients with ANCA-associated glomerulonephritis, diagnosed in our center from 1997 to 2010, were included in this retrospective study. The renal specimens were reviewed according to the proposed histopathologic classification. The predictive value of the classification for renal outcome and renal response to treatment was analyzed.

RESULTS

Thirty-three (27.3%), 24 (19.8%), 53 (43.8%) and 11 (9.1%) patients were classified as focal, mixed, crescentic and sclerotic ANCA-associated glomerulonephritis, respectively. The renal biopsy categories correlated with initial serum creatinine and the renal response to treatment (P < 0.001, P < 0.01, respectively). The probability of progressing to end-stage renal disease (ESRD) increased with ascending categories of focal, mixed, crescentic and sclerotic glomerulonephritis (P < 0.01). The patients with focal, mixed and crescentic ANCA-associated glomerulonephritis were all at decreased risk for developing ESRD compared with the patients with in the sclerotic category (P < 0.05).

CONCLUSIONS

The proposed classification system was re-evaluated for the first time in a relatively large and independent series of patients. This system reflects the severity of the initial renal impairment and can predict, at least to some extent, the renal response to treatment. More importantly, it can independently predict renal outcome, in particular development of ESRD.

The serum level of fibroblast growth factor-23 and calcium-phosphate homeostasis in obese perimenopausal women

Plasma FGF-23 concentrations and its relationship with calcium-phosphate homeostasis were evaluated in 48 perimenopausal obese women and in 29 nonobese controls. Serum parathyroid hormone, 25-hydroxyvitamin D(3), CTX1, osteocalcin, total calcium, phosphorus, creatinine, and plasma intact FGF-23 concentrations were assessed. DXA of lumbar spine and femoral neck was performed to determine bone mineral density (BMD). Plasma iFGF-23 concentration was significantly higher in obese patients (by 42%) and correlated with age and BMD of proximal femur (R = -0.346; R = 0.285, resp.) but not with markers of bone turnover. However, serum phosphorus level in obese subjects was significantly lower. iFGF-23 concentration correlated significantly with body mass index (R = 0.292) and fat content (R = 0.259) in all study subjects. Moreover, a significant correlation between iFGF-23 and iPTH (R = 0.254) was found. No correlation between serum phosphorus or eGFR and plasma iFGF-23 and between eGFR and serum phosphorus was found. Elevated serum iFGF-23 concentration may partially explain lower phosphorus levels in the obese and seems not to reflect bone turnover.

Association between GFR, proteinuria, and adverse outcomes among White, Chinese, and South Asian individuals in Canada

BACKGROUND

We investigated the association between proteinuria, estimated glomerular filtration rate (eGFR), and risk of mortality and kidney failure in white, Chinese, and South Asian populations.

STUDY DESIGN

Population-based cohort study.

SETTING & PARTICIPANTS

Participants from Alberta, Canada, with a serum creatinine and urine protein dipstick measurement from January 1, 2005, to December 31, 2005.

PREDICTOR

White, Chinese, or South Asian ethnicity.

OUTCOMES

Prevalence of proteinuria by level of eGFR (estimated using the MDRD [Modification of Diet in Renal Disease] Study equation) and the association between eGFR, proteinuria, and all-cause mortality and kidney failure.

MEASUREMENTS

Rates of all-cause mortality and kidney failure per 1,000 person-years were calculated using Poisson regression by ethnicity, eGFR level, and proteinuria level while adjusting for sociodemographic variables and comorbid conditions.

RESULTS

Of 491,729 participants, 5.3% were Chinese and 4.7% were South Asian. For participants with eGFR <60 mL/min/1.73 m(2), the prevalence of heavy proteinuria was higher in Chinese and South Asians compared with whites. Compared with whites, adjusted rates of death were significantly lower for Chinese and South Asian populations (rate ratios, 0.67 [95% CI, 0.56-0.80] and 0.73 [95% CI, 0.59-0.88], respectively); these rate ratios did not vary by eGFR and proteinuria levels.

LIMITATIONS

Using surname to identify ethnicity has the potential for misclassification due to name changes and identical last names from different ethnic groups. Also, to be eligible for inclusion, participants had to have a measurement of serum creatinine and urine dipstick proteinuria.

CONCLUSIONS

Although increasing proteinuria and lower eGFR predicted mortality and progression to kidney failure in all 3 ethnic groups, both Chinese and South Asian populations experienced a lower risk of death and similar risk of kidney failure compared with whites at all eGFR and proteinuria levels. Studies exploring this association further are required.

Clinical outcome of hyperuricemia in IgA nephropathy: a retrospective cohort study and randomized controlled trial

BACKGROUND

Hyperuricemia is an independent risk factor for renal progression in IgA nephropathy (IgAN). However, no study has evaluated the effect of allopurinol on the clinical outcome in hyperuricemic IgAN.

METHODS

First,a retrospective cohort study of 353 IgAN patients was conducted to explore the relationship between uric acid (UA) and the progression of renal disease over a mean period of 5 years. Then, 40 hyperuricemic IgAN patients were randomized to receive allopurinol (100-300 mg/day) or usual therapy for 6 months. The study outcomes were renal disease progression and/or blood pressure.

RESULTS

Hyperuricemia independently predicted renal survival at 1, 3, and 5 years after adjustment for different baseline estimated glomerular filtration rates. In the randomized controlled trial, allopurinol did not significantly alter renal progression or proteinuria. The antihypertensive drug dosage was reduced in 7 of 9 cases with hypertension in the allopurinol group compared to 0 of 9 cases in the control group (p < 0.01). UA levels correlated with mean arterial pressure in normotensive patients (r = 0.388, p < 0.001).

CONCLUSION

Hyperuricemia predicts the progression of IgAN independently of baseline estimated glomerular filtration rate. Allopurinol may improve the control of blood pressure. Further studies are required to explore the effects of lowering UA on renal protection in IgAN.

A comparison of clinical outcomes of Chinese sirolimus-eluting stents versus foreign sirolimus-eluting stents for the treatment of coronary artery disease

BACKGROUND

Chinese sirolimus-eluting stents (SES) have been widely used in recent years. However, the comparison of clinical outcomes between Chinese and foreign SES remains unknown.

OBJECTIVES

To compare the outcomes of Chinese SES (Firebird) with foreign SES (Cypher Select) in the treatment of patients undergoing percutaneous coronary intervention (PCI).

METHODS

4000 consecutive patients treated with SESs from January 2008 to December 2009 were included in this study. Based on the differences of the stents, the patients were divided into a Chinese SES group (Firebird; n = 2008) and a foreign SES group (Cypher Select; n = 1992). Outcomes were monitored for 1 year. The primary clinical endpoint was major adverse cardiac events (MACE): a composite of death, non-fatal myocardial infarction (MI) and target-vessel revascularisation (TVR).

RESULTS

No differences were observed in the incidence of MACE (17.8% vs. 18.6%, p = 0.514) and TVR rate (9.0% vs. 8.6%, p = 0.632) during 1-year follow-up.

CONCLUSIONS

Chinese SES and foreign SES have similar effects on 1-year clinical outcomes and safety.

Extracellular fluid volume and glomerular filtration rate in 1878 healthy potential renal transplant donors: effects of age, gender, obesity and scaling

Aim. The aim of this study was to investigate the influence of age, gender, obesity and scaling on glomerular filtration rate (GFR) and extracellular fluid volume (ECV) in healthy subjects.

METHODS

This is a retrospective multi-centre study of 1878 healthy prospective kidney transplant donors (819 men) from 15 centres. Age and body mass index (BMI) were not significantly different between men and women. Slope-intercept GFR was measured (using Cr-51-EDTA in 14 centres; Tc-99m-DTPA in one) and scaled to body surface area (BSA) and lean body mass (LBM), both estimated from height and weight. GFR was also expressed as the slope rate constant, with one-compartment correction (GFR/ECV). ECV was measured as the ratio, GFR to GFR/ECV.

RESULTS

ECV was age independent but GFR declined with age, at a significantly faster rate in women than men. GFR/BSA was higher in men but GFR/ECV and GFR/LBM were higher in women. Young women (<30 years) had higher GFR than young men but the reverse was recorded in the elderly (>65 years). There was no difference in GFR between obese (BMI>30 kg/m2) and non-obese men. Obese women, however, had lower GFR than non-obese women and negative correlations were observed between GFR and both BMI and %fat. The decline in GFR with age was no faster in obese versus non-obese subjects. ECV/BSA was higher in men but ECV/LBM was higher in women. ECV/weight was almost gender independent, suggesting that fat-free mass in women contains more extracellular water. BSA is therefore a misleading scaling variable.

CONCLUSION

There are several significant differences in GFR and ECV between healthy men and women.

Cardiovascular risk management in chronic kidney disease in general practice (the AusHEART study)

BACKGROUND

Chronic kidney disease (CKD) is common and increasing in prevalence. Adverse outcomes of CKD can be prevented through early detection and treatment. There is limited data on the awareness of CKD and the quality of care offered to patients with CKD in the primary care setting. The objectives of this study were to assess the prevalence, general practitioner (GP) awareness and extent of current evidence-practice gaps in the management of CKD in Australian primary care.

METHODS

The Australian Hypertension and Absolute Risk Study (AusHEART) was a nationally representative, cluster stratified, cross-sectional survey among 322 GPs. Each GP was asked to provide data for 15-20 consecutive patients (age ≥ 55 years) who presented between April and June, 2008. The main outcome measures were CKD prevalence based on proteinuria and decreased estimated glomerular filtration rate. Evidence-practice gaps in management of patients with CKD were identified.

RESULTS

Among a total of 4966 patients with kidney function test data, 1845 (37%) had abnormal kidney function. Of the 1312 patients with abnormal kidney function known to the GP at the time of visit, only 235 were correctly identified as having CKD. GPs under-estimated cardiovascular (CV) risks in patients with CKD when compared with the prevailing guidelines at the time of survey and the recent national guidelines, particularly in later stages of CKD. Among CKD patients not prescribed blood pressure-lowering agents or lipid-lowering agents, treatment was indicated as per relevant guidelines in 51 and 46%, respectively. For CKD patients who were already prescribed blood pressure-lowering and lipid-lowering agents, 61 and 50%, respectively, did not meet the treatment targets recommended by the relevant guidelines.

CONCLUSIONS

CKD is common, significantly under-recognized and under-treated in primary care. Effort to increase awareness and provide opportunities for improved screening and assessment should improve the management and outcome of these patients at high risk of CV disease.

CPVL/CHN2 genetic variant is associated with diabetic retinopathy in Chinese type 2 diabetic patients

OBJECTIVE

Diabetic nephropathy and retinopathy are two important microvascular diabetes complications with a high concordance rate in diabetic patients. A recent genome-wide association study in type 1 diabetic patients of European descent identified four loci to be associated with diabetic nephropathy. The aim of this study was to test the effects of single nucleotide polymorphisms (SNPs) from these four loci on diabetic nephropathy and retinopathy in Chinese type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

In stage 1, we recruited 1,276 type 2 diabetic patients, including 378 patients with diabetic nephropathy but no retinopathy, 374 patients with diabetic retinopathy but no nephropathy, 244 patients with both diabetic retinopathy and nephropathy, and 280 control subjects with diabetes for >10 years and no diabetic retinopathy or nephropathy. Fifty-five SNPs from four loci (CPVL/CHN2, FRMD3, CARS, and IRS2) were genotyped. The SNPs that showed associations to diabetic retinopathy or nephropathy were genotyped in stage 2 samples for replication.

RESULTS

SNPs from CPVL/CHN2 and FRMD3 were associated with diabetic retinopathy with rs39059 and rs10868025 as the top SNPs (odds ratio [OR] 1.292, 95% CI 1.097-1.523, P = 0.0022, for rs39059; 1.201, 1.014-1.422, P = 0.0343, for rs10868025) in stage 1 samples. In stage 2 analysis, only rs39059 showed similar effect to diabetic retinopathy (OR 1.269, 0.989-1.628, P = 0.0689), and meta-analysis showed a significant association between rs39059 and diabetic retinopathy, with an OR of 1.285 (1.120-1.474, P = 0.0003). CPVL/CHN2 rs39059 was also associated with levels of diabetic retinopathy (P = 0.0007 for trend). However, no association was detected between these SNPs and diabetic nephropathy.

CONCLUSIONS

In this study, we found CPVL/CHN2 rs39059 was associated with diabetic retinopathy in the Chinese type 2 diabetic patients.

The association between plasma uric acid and renal function decline in a Chinese population-based cohort

BACKGROUND

Uric acid may be associated with kidney damage through multiple pathways. Previous cohort studies revealed inconsistent results, and research among the non-hypertensive and non-diabetic population are extremely limited.

METHODS

This prospective cohort study included 1410 residents aged 59.1 ± 9.4 years from an urban district of Beijing, China. All participants had an estimated glomerular filtration rate >60 mL/min/1.73m(2). Plasma uric acid was assessed at baseline; and its relation with renal function decline after 4 years' follow-up was analyzed.

RESULTS

During 4 years (5630 person-years) of follow-up, 168 patients (11.9%) developed renal function decline. After adjusting for potential confounders including baseline renal function, plasma uric acid levels were independently associated with an increased risk of renal function decline, with a fully adjusted odds ratio (OR) of 1.19 [per 1 mg/dL increase; 95% confidence interval (CI) 1.04-1.38]. Analysis among 615 hypertension-free and diabetes-free participants yielded similar results, with an adjusted OR of 1.50 (per 1 mg/dL increase; 95% CI 1.13-1.98).

CONCLUSION

Our prospective cohort study revealed that plasma uric acid level is independently associated with an increasing likelihood of renal function decline.

Oral calcitriol for reduction of proteinuria in patients with IgA nephropathy: a randomized controlled trial

BACKGROUND

Vitamin D has shown efficacy in the reduction of proteinuria in patients with chronic kidney disease. This study aimed to determine the effect of calcitriol on urinary protein excretion in patients with immunoglobulin A (IgA) nephropathy.

STUDY DESIGN

Open-label, non-placebo-controlled, randomized study.

SETTING & PARTICIPANTS

50 patients with IgA nephropathy were enrolled. The main criterion for inclusion was urinary protein excretion >0.8 g/d after renin-angiotensin system-inhibitor treatment for at least 3 months.

INTERVENTION

Patients were randomly assigned (1:1) to receive 2 doses (0.5 μg) of calcitriol per week or no treatment for 48 weeks.

OUTCOMES

The primary end point was to compare change in 24-hour urinary protein excretion from baseline to last measurement during treatment.

MEASUREMENTS

Every 8 weeks, there was measurement of 24-hour urinary protein excretion, serum calcium, serum phosphorus, serum creatinine, and intact parathyroid hormone.

RESULTS

Measurement of the primary end point showed changes in urinary protein excretion of +21% (from 1.29 to 1.58 g/24 h; 95% CI, -9% to +52%) in the control group and -19% (from 1.60 to 1.30 g/24 h; 95% CI, -42% to +4%) in the calcitriol-treated group. There was a significant decrease in proteinuria in the calcitriol-treated group compared with the control group (difference between groups, 41%; 95% CI, 5%-79%; P = 0.03). The secondary end point of achieving at least a 15% decrease in proteinuria was attained by 7 of 24 (29%) controls and 17 of 26 (65%) of those treated with calcitriol (P = 0.02). No significant differences were observed in decrease in estimated glomerular filtration rate and change in blood pressure between the 2 groups. The incidence of recorded adverse events was similar between the 2 groups.

LIMITATIONS

Small and non-placebo-controlled study.

CONCLUSIONS

The addition of calcitriol to a renin-angiotensin system inhibitor resulted in a safe decrease in proteinuria in patients with IgA nephropathy.

Cellular and molecular mechanisms of renal fibrosis

Renal fibrosis, particularly tubulointerstitial fibrosis, is the common final outcome of almost all progressive chronic kidney diseases. Renal fibrosis is also a reliable predictor of prognosis and a major determinant of renal insufficiency. Irrespective of the initial causes, renal fibrogenesis is a dynamic and converging process that consists of four overlapping phases: priming, activation, execution and progression. Nonresolving inflammation after a sustained injury sets up the fibrogenic stage (priming) and triggers the activation and expansion of matrix-producing cells from multiple sources through diverse mechanisms, including activation of interstitial fibroblasts and pericytes, phenotypic conversion of tubular epithelial and endothelial cells and recruitment of circulating fibrocytes. Upon activation, matrix-producing cells assemble a multicomponent, integrin-associated protein complex that integrates input from various fibrogenic signals and orchestrates the production of matrix components and their extracellular assembly. Multiple cellular and molecular events, such as tubular atrophy, microvascular rarefaction and tissue hypoxia, promote scar formation and ensure a vicious progression to end-stage kidney failure. This Review outlines our current understanding of the cellular and molecular mechanisms of renal fibrosis, which could offer novel insights into the development of new therapeutic strategies.

The contribution of chronic kidney disease to the global burden of major noncommunicable diseases

Noncommunicable diseases (NCDs) are the most common causes of premature death and morbidity and have a major impact on health-care costs, productivity, and growth. Cardiovascular disease, cancer, diabetes, and chronic respiratory disease have been prioritized in the Global NCD Action Plan endorsed by the World Health Assembly, because they share behavioral risk factors amenable to public-health action and represent a major portion of the global NCD burden. Chronic kidney disease (CKD) is a key determinant of the poor health outcomes of major NCDs. CKD is associated with an eight- to tenfold increase in cardiovascular mortality and is a risk multiplier in patients with diabetes and hypertension. Milder CKD (often due to diabetes and hypertension) affects 5-7% of the world population and is more common in developing countries and disadvantaged and minority populations. Early detection and treatment of CKD using readily available, inexpensive therapies can slow or prevent progression to end-stage renal disease (ESRD). Interventions targeting CKD, particularly to reduce urine protein excretion, are efficacious, cost-effective methods of improving cardiovascular and renal outcomes, especially when applied to high-risk groups. Integration of these approaches within NCD programs could minimize the need for renal replacement therapy. Early detection and treatment of CKD can be implemented at minimal cost and will reduce the burden of ESRD, improve outcomes of diabetes and cardiovascular disease (including hypertension), and substantially reduce morbidity and mortality from NCDs. Prevention of CKD should be considered in planning and implementation of national NCD policy in the developed and developing world.

Measuring the population burden of chronic kidney disease: a systematic literature review of the estimated prevalence of impaired kidney function

BACKGROUND

Internationally, there have been substantial efforts to improve the early identification of chronic kidney disease (CKD), with a view to improving survival, reducing progression and minimizing cardiovascular morbidity and mortality. In 2002, a new and globally adopted definition of CKD was introduced. The burden of kidney function impairment in the population is unclear and widely ranging prevalence estimates have been reported.

METHODS

We conducted a systematic literature review, searching databases to June 2009. We included all adult population screening studies and studies based on laboratory or clinical datasets where the denominator was clear. Studies reporting prevalence estimates based on at least one eGFR <60 mL/min/1.73m(2) or elevated creatinine above a stated threshold were included. Study design and quality were explored as potential factors leading to heterogeneity.

RESULTS

We identified 43 eligible studies (57 published reports) for inclusion. Substantial heterogeneity was observed with estimated prevalence (0.6-42.6%). The included studies demonstrated significant variation in methodology and quality that impacted on the comparability of their findings. From the higher quality studies, the six studies measuring impaired kidney function (iKF) using estimated glomerular filtration rate in community screening samples reported a prevalence ranging from 1.7% in a Chinese study to 8.1% in a US study, with four reporting an estimated prevalence of 3.2-5.6%. Heterogeneity was driven by the measure used, study design and study population.

CONCLUSION

In the general population, estimated iKF, particularly eGFR 30-59 mL/min/1.73m(2) was common with prevalence similar to diabetes mellitus. Appropriate care of patients poses a substantial global health care challenge.

Glomerular filtration rate estimation in patients with type 2 diabetes: creatinine- or cystatin C-based equations?

AIMS/HYPOTHESIS

It is argued that GFR estimation (eGFR) using cystatin C-based equations (eGFRcys) is superior to that using creatinine-based equations (eGFRcre). We investigated whether eGFRcys are superior to eGFRcre in patients with type 2 diabetes.

METHODS

GFR was measured in 448 type 2 diabetic patients using (51)Cr-EDTA-measured GFR (mGFR) as the reference standard. Bias, precision and accuracy of eGFRcys and eGFRcre were compared.

RESULTS

The most accurate eGFRcre equation (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), which produced the highest proportion of estimates that were within 30% and 10% of the reference standard (80.7% and 38.0% of samples, respectively) had a bias of 7.1 and precision of 12.0 ml min(-1) 1.73 m(-2). The calibrated eGFRcys with the highest accuracy (Tan-C), which produced the highest proportion of estimates that were within 30% (78.8%) and within 10% (39.0%) of the reference standard had a bias of -3.5 and precision of 18.0 ml min(-1) 1.73 m(-2). Moreover, the areas under the receiver operating curve were higher with eGFRcre (CKD-EPI and Modification of Diet in Renal Disease [MDRD]) than with eGFRcys for the diagnosis of mild (mGFR <90 ml min(-1) 1.73 m(-2)) and moderate (mGFR <60 ml min(-1) 1.73 m(-2)) chronic kidney disease. In patients with mGFR ≥90 ml min(-1) 1.73 m(-2), CKD-EPI was the least biased, the most precise and the most accurate equation.

CONCLUSIONS/INTERPRETATION

In patients with type 2 diabetes, eGFRcys do not currently provide better eGFR than eGFRcre. At present, compared with eGFRcys, eGFRcre are better at predicting the stage of chronic kidney disease. In addition, CKD-EPI seems to be the best equation for eGFR in patients with normal renal function.

Screening of a population at risk of chronic kidney disease: analysis of factors associated with low eGFR and microalbuminuria

BACKGROUND AND OBJECTIVE

Numerous screenings of chronic kidney disease (CKD) have been performed all over the world. This screening study was undertaken with the aim of estimating the prevalence of low glomerular filtration rate (eGFR) and microalbuminuria (MAU) and/or proteinuria in a population at risk for CKD and to detect factors associated with these CKD markers.

MATERIALS AND METHODS

This cross-sectional study included 1617 patients without previously known kidney disease who came for regular check-ups to their general practitioners in 13 Belgrade health centers over a 3-month period. Patients selected were as follows: 1316 with hypertension, 208 with type 2 diabetes, and 93 older than 60 years without hypertension or diabetes. Screening included a questionnaire, blood pressure measurement, single MAU dipstick measurement (Micral-test® strip) and proteinuria and GFR estimation by Modification of Diet in Renal Disease.

RESULTS

MAU was found in 419 (25.9%) patients, proteinuria in 163 (10.1%), and eGFR < 60 mL/min/1.73 m(2) in 370 (22.9%). Multivariate logistic regression analysis revealed that female gender, age, duration of hypertension, and smoking were associated with eGFR. Male gender, hypertension, treatment with angiotensin-converting enzyme inhibitors, proteinuria, and systolic blood pressure were associated with MAU.

CONCLUSIONS

High prevalence of MAU/proteinuria and reduced eGFR were found in high-risk persons for CKD. Besides nonmodifiable, significant modifiable factors for MAU were use of angiotensin-converting enzyme inhibitors and strict regulation of hypertension and the factor for reduced eGFR was smoking.

Detection of urinary abnormalities in a community from northern Italy based on the World Kidney Day screening program

BACKGROUND

Chronic kidney disease (CKD) is a worldwide health problem, and promotion of the World Kidney Day has improved general population education and awareness of renal illnesses aimed at ameliorating disease prevention. The Kidney Day was also an opportunity for us to investigate risk factors for CKD in an Italian population.

PATIENTS AND METHODS

A total of 1,341 subjects from the general population living in the area of Ferrara, a town in the northeast of Italy, aged 50-70 years, were investigated. From each participant age, sex, smoking status, current antihypertensive medications, hypercholesterolemic and diabetic status, body mass index (BMI), waist circumference and blood pressure (BP) were obtained. All subjects underwent dipstick urinalysis for the evaluation of proteinuria, hematuria and leukocyturia.

RESULTS

Fifteen percent of patients were diabetics, and 20% were smokers. Mean BMI was 26.9 ± 4.3 kg/m(2), mean systolic BP was 133.7 ± 18.7 mmHg and mean diastolic BP 78.1 ± 9.9 mmHg. A total of 828 participants were not taking any antihypertensive drugs. In 24% of subjects, we found proteinuria, in 18% hematuria and in 16% leukocyturia. Proteinuria was significantly associated with age and diabetes, hematuria was associated with age, female sex and smoking status, and leukocyturia was associated with age and female sex.

CONCLUSIONS

Urinary abnormalities are common in general population, and in many cases, various abnormalities overlap. These abnormalities could be associated with cardiovascular risk factors. We believe that our initiative, based on the experience of the World Kidney Day, could increase the awareness of general practitioners and general population of the risks of renal conditions.

Mortality and renal function decline among a community-based Chinese population with normal or mildly impaired renal function

BACKGROUND

Longitudinal studies of the mortality and renal outcomes among the population with an estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m(2) and among the elderly are limited, especially in developing countries.

METHODS

This prospective cohort study included 1563 residents aged 59.5 ± 9.4 years from an urban district of Beijing, China. All participants had an eGFR >30 mL/min/1.73 m(2). Urinary albumin-to-creatinine ratio and eGFR were assessed at baseline, and their relation with mortality and renal function decline after a 4-year follow-up were analyzed.

RESULTS

During 4 years (6142 person-years) of follow-up, 59 deaths occurred (9.6 per 1000 person-years). After adjusting for potential confounders, albuminuria was associated with increased risk of mortality, with an odds ratio (OR) of 3.09 [95% confidence interval (CI) 1.53-6.26]. Altogether 183 patients (12.3%) developed renal function decline, with a median change of eGFR of -20.0 mL/min/1.73 m(2). Presence of albuminuria was significantly associated renal function decline, with an OR of 1.79 (95% CI 1.02-3.15). Plasma uric acid (OR = 1.25/59 μmol/L increase, 95% CI 1.10-1.43) and age (OR = 1.35/5 years increase, 95% CI 1.22-1.50) was also independently associated with renal function decline. Baseline eGFR was not significantly associated with either mortality or renal function decline in our analysis.

CONCLUSIONS

Compared with eGFR, albuminuria is a strong independent predictor for both mortality and renal function decline among a Chinese population with normal or mildly impaired renal function. Furthermore, plasma uric acid level and age are also independently associated with renal function decline and therefore may be used for identifying patients at higher risk of chronic kidney disease progression.

A new tool to detect kidney disease in Chinese type 2 diabetes patients: comparison of EZSCAN with standard screening methods

BACKGROUND

EZSCAN(®) (Impeto Medical, Paris, France), a noninvasive device that assesses sweat gland dysfunction using reverse iontophoresis, also detects early dysglycemia. Given the interrelationships among dysglycemia, vasculopathy, and neuropathy, EZSCAN may detect kidney disease in diabetes (DKD).

METHODS

An EZSCAN score (0-100) was calculated using a proprietary algorithm based on the chronoamperometry analysis. We measured the score in 50 Chinese type 2 diabetes patients without DKD (urinary albumin-creatinine ratio [ACR] <2.5 mg/mmol in men or ACR <3.5 mg/mmol in women and estimated glomerular filtration rate [eGFR] >90 mL/min/1.73 m(2)) and 50 with DKD (ACR ≥25 mg/mmol and eGFR <60 mL/min/1.73 m(2)). We used spline analysis to determine the threshold value of the score in detecting DKD and its sensitivity and specificity.

RESULTS

EZSCAN scores were highly correlated with log values of eGFR (r=0.67, P<0.0001) and ACR (r=-0.66, P<0.0001). Using a cutoff value of 55, the score had 94% sensitivity, 78% specificity, and a likelihood ratio of 4.2 to detect DKD with a positive predictive value of 81% and a negative predictive value of 93%. On multivariable analysis, DKD was independently associated with EZSCAN score (β=-0.72, P=0.02), smoking status (1=never, 0=current/former) (β=-2.37, P=0.02), retinopathy (1=yes, 0=no) (β=3.019, P=0.01), triglycerides (β=2.56, P=0.013), and blood hemoglobin (β=-0.613, P=0.04). Patients without DKD but low EZSCAN score (n=10) had longer duration of disease (median [interquartile range], 13 [9-17] vs. 8 [4-16] years; P=0.017) and were more likely to have retinopathy (36.7% vs. 5.1%, P=0.02), lower eGFR (98 [95.00-103] vs. 106 [98.5-115], P=0.036), and treatment with renin-angiotensin system blockers (81.8% vs. 25.6%, P=0.002) than those with a normal score.

CONCLUSION

EZSCAN may detect high-risk subjects for DKD in Chinese populations.

IL-6 levels, nutritional status, and mortality in prevalent hemodialysis patients

BACKGROUND AND OBJECTIVES

The influence of serum IL-6 levels on nutritional status in chronic hemodialysis (HD) patients remains to be elucidated. The present report describes a prospective longitudinal study of IL-6 levels and nutritional parameters to determine whether high IL-6 levels are independently associated with nutritional status over time in a cohort of prevalent hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

85 clinically stable hemodialysis patients (37.6% women), with a mean age of 66.5 ± 10.6 years, were studied after exclusion of patients with BMI < 20 kg/m(2) and/or serum albumin <35 g/L. IL-6, dietary energy and protein intake, and biochemical markers of nutrition and body composition (anthropometry and bioimpedance analysis) were measured at baseline and at 6, 12, 18, and 24 months following enrollment. Observation of this cohort was continued over 2 additional years.

RESULTS

IL-6 levels increased with time in both unadjusted (linear estimate: 2.57 ± 0.44 pg/ml per 2 yrs; P = 0.001) and adjusted models (linear estimate: 2.35 ± 0.57 pg/ml per 2 yrs; P = 0.049). Significant reductions of daily energy intake, laboratory markers (albumin, transferrin, cholesterol, creatinine), and body composition (fat mass) with higher IL-6 levels were observed over the duration of the longitudinal observation period. However, none of the studied parameters were associated with changes in IL-6 levels over time (IL-6-by-time interactions were NS). Furthermore, cumulative incidences of survival were correlated with the baseline serum IL-6 levels (P = 0.004 by log-rank test). Finally, for each pg/ml increase in IL-6 level, the hazard ratio for death from all causes was 1.06 (95% CI 1.01 to 1.10) after adjustment for demographic and clinical parameters.

CONCLUSIONS

Our results suggest that higher serum IL-6 levels are associated with all-cause mortality without additional changes in clinical and laboratory markers of nutritional status in clinically stable HD patients.

Pathologic predictors of renal outcome and therapeutic efficacy in IgA nephropathy: validation of the oxford classification

BACKGROUND AND OBJECTIVES

The Oxford classification of IgA nephropathy (IgAN) may aid in predicting prognosis and providing therapeutic strategy but must be validated in different ancestry.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 410 patients with IgAN, enrolled from one of the largest renal centers in China, were evaluated for the predictive value of the Oxford classification to prognosis defined as end stage renal disease. A total of 294 of these patients were prospectively treated with renin-angiotensin system blockade and immunosuppressants sequentially and were evaluated separately to assess the predictive value to therapeutic efficacy (defined as time-averaged proteinuria <1 g/d). Three pathologists reviewed specimens independently according to the Oxford classification and were blinded to clinical data.

RESULTS

Segmental glomerulosclerosis and tubular atrophy and interstitial fibrosis were independent predictive factors of end stage renal disease. Patients who had >25% of glomeruli with endocapillary hypercellularity showed higher proteinuria, lower estimated GFR, and higher mean BP than patients with less endocapillary hypercellularity. Immunosuppressive therapy showed a protective effect to prognosis of endocapillary hypercellularity in patients with endoncapillary hypercellularity could benefit from immunosuppressive therapy. Mesangial hypercellularity and tubular atrophy and interstitial fibrosis were independent factors of inefficiency of renin-angiotensin system blockade alone. Crescents were not significant in predicting prognosis or in therapeutic efficacy.

CONCLUSIONS

The Oxford classification may aid in predicting prognosis and providing a therapeutic strategy in Chinese patients with IgAN.

Implication of CKD-EPI equation to estimate glomerular filtration rate in Chinese patients with chronic kidney disease

OBJECTIVE

To evaluate the applicability of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation to estimate glomerular filtration rate (GFR) in Chinese patients of different stages of CKD.

METHODS

The CKD-EPI equation estimated GFR (eGFR) was compared with body surface area standardized GFR (sGFR), which was measured by diethylenetriaminepentaacetic acid renal dynamic imaging method in 142 CKD cases.

RESULTS

eGFR was positively correlated with sGFR (r = 0.838, p < 0.001). eGFR of 15%, 30%, and 50% accuracy were 31.0%, 57.7%, and 76.8%, respectively. Average deviation of eGFR from sGFR was -0.92 ± 16.36 mL/min/1.73 m2 (p = 0.506). There was no significant deviation in the CKD from stages 2 to 5. However, in CKD stage 1, the deviation was increased with the value of 13.36 ± 18.44 mL/min/1.73 m(2) (p = 0.023).

CONCLUSION

CKD-EPI equation might be widely used in evaluation of Chinese CKD patients of different stages, with a less deviation and higher accuracy. However, in CKD stage 1, eGFR was higher than sGFR on average. It was suggested that eGFR might be overcorrected or overestimated. These results demonstrated that careful modification of CKD-EPI equation would be necessary in Chinese populations with CKD.

Acute-on-chronic kidney injury at hospital discharge is associated with long-term dialysis and mortality

Existing chronic kidney disease (CKD) is among the most potent predictors of postoperative acute kidney injury (AKI). Here we quantified this risk in a multicenter, observational study of 9425 patients who survived to hospital discharge after major surgery. CKD was defined as a baseline estimated glomerular filtration rate <45 ml/min per 1.73 m(2). AKI was stratified according to the maximum simplified RIFLE classification at hospitalization and unresolved AKI defined as a persistent increase in serum creatinine of more than half above the baseline or the need for dialysis at discharge. A Cox proportional hazard model showed that patients with AKI-on-CKD during hospitalization had significantly worse long-term survival over a median follow-up of 4.8 years (hazard ratio, 1.7) [corrected] than patients with AKI but without CKD.The incidence of long-term dialysis was 22.4 and 0.17 per 100 person-years among patients with and without existing CKD, respectively. The adjusted hazard ratio for long-term dialysis in patients with AKI-on-CKD was 19.8 compared to patients who developed AKI without existing CKD. Furthermore, AKI-on-CKD but without kidney recovery at discharge had a worse outcome (hazard ratios of 4.6 and 213, respectively) for mortality and long-term dialysis as compared to patients without CKD or AKI. Thus, in a large cohort of postoperative patients who developed AKI, those with existing CKD were at higher risk for long-term mortality and dialysis after hospital discharge than those without. These outcomes were significantly worse in those with unresolved AKI at discharge.