MDRD Study Equation Research Articles

MO955: Serum Cystatin C in Renal Transplantation: Beyond GFR Estimation, A Prognosis Marker?

Abstract BACKGROUND AND AIMS In renal transplantation, death with a functioning graft remains one of the main causes of graft loss. In the general population, renal function impairment is strongly associated with cardiovascular and all-cause mortality. Whether this association holds true for kidney transplant recipients (KTR) is unclear. This uncertainty is likely to be due, in part, to the fact that glomerular filtration rate (GFR) estimation based on serum creatinine (SCr) does not always provide an accurate evaluation of the graft function in KTR. As compared to SCr, we have previously shown in a large cohort of KTR that serum cystatin C (SCysC) is a much better marker of GFR. Herein, we sought to study the ability of the 1-year-post-transplant renal function to predict all-cause mortality according to the methods used to assess GFR. METHOD Four hundred and ten consecutive KTR for whom a measurement of GFR by inulin clearance was available at 1 year post-transplant were included. SCr and ScysC were measured with standardized methods. The association of the 1-year inulin clearance value the 1-year MDRD Study equation value and the 1-year CKD-EPI ScysC equation value with all-cause mortality was studied by ROC analysis and Cox model. RESULTS During a median follow-up of 17 years, 131 KTR died. Mean (±SD) inulin clearance at 1-year-post-transplant was 47 (±13) mL/min/1.73 m2. Areas under the ROC curves were similar for inulin and CKD-EPI ScysC equation values (0.62 for both), and were both significantly superior to that of the MDRD equation (0.54, P < 0.01). In Cox analysis, while all types of GFR evaluations were significantly associated to graft loss, only an inulin and a CKD-EPI ScysC equation values below 45 mL/min/1.73 m2 were associated with an excess risk of mortality (HR of 1.55, 1.45 and 1.01 for inulin, CKD-EPI ScysC and MDRD, respectively). CONCLUSION We conclude that ScysC-based GFR estimation might better predict KTR outcome as compared with a traditional SCr-based estimation. The one year-post transplant GFR value given by the CKD-EPI ScysC equation should be further evaluated as a potential surrogate marker for both graft and patient survival.

MDRD or CKD-EPI study equations for estimating prevalence of stage 3 CKD in Moroccan population

MDRD or CKD-EPI study equations for estimating prevalence of stage 3 CKD in Moroccan population

Estimation of glomerular filtration rate from skeletal muscle mass. A new equation independent from age, weight, gender, and ethnicity

Background and aimsThe most used indicator for the renal function is the glomerular filtration rate (GFR). Current used predictive GFR equations were calibrated on patients with chronic kidney disease. Thus, they are not very precise in healthy individuals. The estimation of skeletal muscle mass (SMM) allows the prediction of the daily urinary creatinine excretion (24hUCrE). This study proposes an equation for the estimation of GFR based on SMM (eGFRMuscle) and serum creatinine (SCr). Methods and resultsFour hundred sixty-six free-living men underwent a bioelectrical impedance analysis for the evaluation of SMM (kg), a blood withdrawal for the measurement of SCr (mg/dL), and a 24-h urinary collection for the assessment of 24hUCrE (g/24 h). The linear regression analysis between SMM and 24hUCrE and the measurement of SCr allowed developing a predictive equation of eGFRMuscle. The equation predicting eGFRMuscle (ml/min/1.73 m2) was SMM (kg) × 3.06/SCr (mg/dL). eGFRMuscle was statistically different from eGFR predicted by Cockroft–Gault, MDRD Study, and CKD-EPI equations (p = 0.017, p < 0.001, and p < 0.001, respectively). Pairwise comparison of standard error of the area under the ROC curve (AUC) of eGFRMuscle with all the other AUCs of ROC curves highlighted significant differences. ConclusionsThe equation presented in this study results in age, weight, gender, and ethnicity independent because it arises directly from SMM estimation. Therefore, the proposed equation could allow evaluating the GFR also in healthy people with low, average, or high weight, and in older people, regardless of GFR and SCr levels.

Comparison of Estimated Glomerular Filtration Rate with Both Serum Creatinine and Cystatin C (eGFRcr-cys) versus Single Analyte (eGFRcr or eGFRcys) Using CKD-EPI and MDRD Equations in Tertiary Care Hospital Settings.

To assess and compare the glomerular filtration rate (eGFR) estimated through MDRD and CKD-EPIcr equations in early and late stages of chronic kidney disease on biochemical marker creatinine (eGFRcr), cystatin C (eGFRcys); and combined (eGFRcr-cys), using CKD-EPI equation. Observational, comparative cross-sectional study. Chemical Pathology and Endocrinology Department, Armed Forces Institute of Pathology (AFIP), Rawalpindi in collaboration with Armed Forces Institute of Urology (AFIU), Rawalpindi from October 2019 to March 2020. GFR was assessed on the basis of creatinine clearance taking serum and 24-hour urinary specimens. MDRD and CKD-EPI equations were applied to calculate eGFR by serum creatinine (eGFRcr), cystatin C (eGFRcys), and combined (eGFRcr-cys). Pearson correlation technique was used to compare eGFR calculated by different equations with creatinine clearance in different stages of CKD. Performance of equations was evaluated and compared in different stage of CKD. A total of 181 subjects were enrolled. Median age was 57 years (IQR, 25). Median (IQR) GFR (ml/min/1.73m2) calculated by CrCl, MDRD, CKD-EPIcr, CKD-EPIcys and CKD-EPIcr-cys equations were 45.1 (41.5), 50.6 (23.8), 52.0 (28.0), 43.0 (65.0) and 45 (47), respectively. eGFR calculated by CKD-EPIcr had positive and slightly higher correlation (r=0.880) than MDRD study equation (r=0.867). While comparing the markers, it was observed that CKD-EPIcys had better correlation in early stages of CKD (r=0.889); whereas, CKD-EPIcr performed better in late stages (r=0.896). CKD-EPIcr-cys had the highest correlation (r=0.984) at all stages of CKD. eGFR calculated by CKD-EPI equation considered as better diagnostic efficient response than MDRD equation in diagnosis and staging of chronic kidney disease. While applying CKD-EPI equation for measurement of eGFR, eGFRcr-cys performs better than any of eGFRcr or eGFRcys at all stages of CKD. Key Words: Estimated glomerular filtration rate (eGFR), Cystatin C (Cys), Creatinine (Cr), Creatinine clearance (CrCl), CKD-EPI equation, MDRD equation.

Attainment of Guideline-Directed Medical Treatment in Stable Ischemic Heart Disease Patients With and Without Chronic Kidney Disease

Stable ischemic heart disease (SIHD) is prevalent in patients with chronic kidney disease (CKD); however, whether guideline-directed medical therapy (GDMT) is adequately implemented in patients with SIHD and CKD is unknown. Use of GDMT and achievement of treatment targets would be higher in SIHD patients without CKD than in patients with CKD. This was a retrospective study of 563 consecutive patients with SIHD (mean age 67.8years, 84% Caucasians, 40% females). CKD was defined as an estimated glomerular filtration rate (eGFR) of < 60mL/min/1.73m2 using the four-variable MDRD Study equation. We examined the likelihood of achieving GDMT targets (prescription of high-intensity statins, antiplatelet agents, renin-angiotensin-aldosterone system inhibitors (RAASi), and low-density lipoprotein cholesterol levels < 70mg/dL, blood pressure < 140/90mmHg, and hemoglobin A1C < 7% if diabetes) in patients with (n = 166) and without CKD (n = 397). Compared with the non-CKD group, CKD patients were significantly older (72 vs 66years; p < 0.001), more commonly female (49 vs 36%; p = 0.002), had a higher prevalence of diabetes (46 vs 34%; p = 0.004), and left ventricular systolic ejection fraction (LVEF) < 40% (23 vs. 10%, p < 0.001). All GDMT goals were achieved in 26% and 24% of patients with and without CKD, respectively (p = 0.712). There were no between-group differences in achieving individual GDMT goals with the exception of RAASi (CKD vs non-CKD: adjusted risk ratio 0.73, 95% CI 0.62-0.87; p < 0.001). Attainment of GDMT goals in SIHD patients with CKD was similar to patients without CKD, with the exception of lower rates of RAASi use in the CKD group.

Impact of estimation versus direct measurement of predonation glomerular filtration rate on the eligibility of potential living kidney donors

While direct measurements of glomerular filtration rate (GFR) provide the most accurate evaluation of pre-donation kidney function, guidelines do not systematically require the use of a reference method. We evaluated whether and to what extent relying upon creatinine-based estimating equations (eGFR) rather than direct measurement of GFR (mGFR) alters the selection of potential living donors. We compared the impact of 4 equations (the MDRD study equation, the CKD-EPI equation, the revised Lund-Malmö equation, and the full age spectrum [FAS] equation) on the evaluation of 2733 potential donors with GFR measured by reference methods. We also considered the impact of using either absolute or age-adapted GFR thresholds. The CKD-EPI and FAS equations had the best performances (P10 of 50.6% and 47.8%; P30 of 94.4% and 93.1%, respectively) and led to the lowest proportion of improperly evaluated candidates. Misclassification was more frequent when GFR adequacy was defined as an absolute threshold of 90 ml/min/1.73m2 as compared to an age-adapted definition (26% and 5%, respectively). Interpretation of eGFR according to an absolute threshold of 90 ml/min/1.73m2 identified 1804 candidates eligible to donate, compared to 2648 when mGFR was interpreted with age-adapted thresholds. We conclude that creatinine-based estimates cannot substitute for direct GFR measurement to evaluate candidates for kidney donation. When reference methods for direct GFR measurement are not available, our data suggest that a strategy based on age-adapted eGFR values estimated with either the CKD-EPI or FAS equation should be preferred.

A study on prevalence of chronic kidney disease and its risk factors among adults in selected slums of Chennai

Background: Chronic kidney disease (CKD) is a silent epidemic. The true prevalence of CKD with in a population are very difficult to estimate, since early to moderate CKD were usually asymptomatic. ESRD in the consequence of CKD is one of the most expensive diseases to treat.Only way is to prevent it and Hence this was conducted to estimate the prevalence of CKD and its associated risk factors among adults in selected slums of Chennai.Methods: This is a cross sectional study done from May 2013 to June 2014 in selected slums of Chennai. The study population includes adult males and females. Multi stage sampling method used. Sample size covered was 400. A semi structured questionnaire used as tool. Based on the serum creatinine eGFR calculated using modified MDRD study equation and CKD prevalence was identified. The data was entered in MS excel and analyzed using SPSS version 21.Results: Total of 400 participants involved. Females were predominant in the study. Among them, 67 (16.8%) were diagnosed as CKD patients and Stage 1, 4.0% had stage 2, 3.6% had stage 3, 1.3% had stage 4 and 0.5% had stage 5 at the time of diagnosis.Conclusions: This study revealed prevalence of CKD among slum population was 16.8%. This study showed that old age, uncontrolled hypertension, uneducated, Diabetes with poor control, overuse of analgesics, H/o smoking, obesity, alcoholism, passive smoking, family H/o CKD and proteinuria were significant risk factor for CKD among study subjects. Slum population with risk factors should be regularly screened for CKD.

109 - High Right Ventricular Stroke Work Index is Associated with Worse Kidney Function in Patients with Heart Failure with Preserved Ejection Fraction (HFpEF)

Background: In patients with heart failure with preserved ejection fraction (HFpEF), worse kidney function is associated with worse overall cardiac mechanics. However, the direct relationship between right ventricular function and kidney function is unclear. Right ventricular stroke work index(RVSWI) is a parameter of right ventricular function. Increased RVSWI indicates higher right ventricular workload. There has been only a single study showing the association between increased RVSWI and increased creatinine in HFpEF. The aim of our study was to determine the relationship between RVSWI and glomerular filtration rate (GFR) in patients with HFpEF. Methods: This was a single center study including patients with HFPEF (left ventricular ejection fraction more than 50%) underwent right heart catheterization between January 2010 and April 2016. Patients with moderate or severe valvular heart disease, end-stage renal disease, prosthetic valve or organ transplant were excluded. A retrospective chart review for demographic data, risk factors, right heart catheterization parameters and laboratory results was done. RVSWI(normal value 8–12 g/m/beat/m2) was calculated using the formula, RVSWI = 0.0136x Stroke volume index x (Mean pulmonary artery pressure-mean right atrial pressure). GFR was calculated using MDRD study equation. Linear regression analysis was done to study the correlation between RVSWI and GFR. Multivariable linear regression analysis was also performed to adjust for potential confounders. Results: A total of 130 patients were included in the study. The patients were predominantly female (n = 88, 66%) and African American (n = 83, 64%). Mean age was 68 ± 12 years; 111 (85%) patients had hypertension, 85(65%) had diabetes mellitus, and 28(22%) were smokers. Mean GFR was 61 ± 33 ml/min/1.73 m2. Mean RVSWI was 11 ± 6 g/m/beat/m2. Linear regression analysis showed that there was a significant inverse relationship between RVSWI and GFR (Beta = -1.32, P = .007). After adjusting for confounders including age, sex, race, hypertension, diabetes mellitus, smoking, and history of coronary artery disease, the association remained significant (Beta = −1.12, P = .024, Table 1). Conclusion: Increased right ventricular stroke work index, which reflects the RV adaptation to increased afterload, is associated with worse renal function in patients with heart failure with preserved ejection fraction. Further prospective studies are needed to better understand this association and establish causal relationship.Table 1multivariable linear regression analysisVariablesBeta95% CI of BetaP-valueRVSWI−1.12−2.08 to −0.15.024Age−0.22−0.75 to 0.30.402Race−3.09−8.27 to 2.10.241Hypertension−9.76−26.65 to 7.13.255Hyperlipidemia16.854.36−2.93.009Diabetes Mellitus−5.29−17.83 to 7.26.406Smoking−0.97−15.48 to 13.54.895Sex15.143.30–26.97.013History of coronary artery disease−13.05−24.57 to −1.53.027 Open table in a new tab

Quality of diabetes mellitus therapy in patients with chronic kidney disease in the real world

Chronic kidney disease (CKD) is very often among diabetic patients. Some oral antidiabetic agents are not recommended in the presence of CKD. Aim of the study was to evaluate the quality of diabetes mellitus (DM) treatment in nephrophatic patients in the real world. A total of 265 subjects with type 2 DM, consecutively admitted to the internal medicine departments of two hospitals in Rome, were recruited. Patients hospitalized for hypoglycemia, decompensated DM, acute kidney failure or worsening nephropathy were excluded. For each patient, the following data were collected: age, gender, estimated glomerular filtration rate (eGFR) using the MDRD (&lt;em&gt;modification of diet in renal disease&lt;/em&gt;) study equation, type of antidiabetic drug treatment. A total of 265 subjects were studied, 127 male (47.9%) and 138 female (52.1%). The mean age was 77.5 years. The mean of glycemia glycated hemoglobin (HbA1c) value was 57.5 mmol/mol (7.4%). 137 patients (51.7%) were treated with oral antidiabetic agents, 29 (10%) with both oral antidiabetic agents and insulin, 90 (34%) with insulin alone, 8 (3%) with dipeptidyl peptidase-4 inhibitors, 1 (0.4%) with incretin agents plus oral antidiabetic drugs. According to the Kidney Disease Outcomes Quality Initiative (KDOQI) classification of CKD, the sample was divided into 5 groups using eGFR criteria. For each group, mean HbA1c values, type of antidiabetic treatment, appropriateness of therapy according to guidelines and how it may affect the HbA1c levels were considered. Our data show that 30.5% of patients with CKD stage 3-5 is treated with drugs not recommended by current guidelines.

Abstract WP313: Quality of Ischemic Stroke-related Care in Patients With Chronic Kidney Disease (CKD) on Dialysis: Findings From Get With the Guidelines-stroke

Objectives: To assess the quality of ischemic stroke-related care based on American Heart Association (AHA) Get With The Guidelines (GWTG)-Stroke metrics for patients receiving dialysis compared to those with less severe or no CKD . Methods: The analysis is based on data from 232,236 Medicare-eligible fee-for-service patients admitted to 1581 GWTG-Stroke participating hospitals between January 2009 and December 2012. GFR was determined based on the MDRD study equation. Patients receiving dialysis were identified by ICD-9 diagnosis codes (V45.11 renal dialysis status, 585.6 end stage renal disease, V56.X encounter for dialysis and dialysis catheter care). Results: Compared to no CKD, dialysis patients received fewer guideline-based therapies (Table). Compared to other CKD stages, dialysis patients less often received VTE prophylaxis, timely treatment with IV-tPA, and defect free care. Treatment with early antithrombotics, discharge on antithrombotics, anticoagulation for atrial fibrillation, and statin use were lowest in patients with CKD stage 5. Conclusion: Among Medicare beneficiaries with acute ischemic stroke, guideline-adherent care is less frequent in patients on dialysis compared to those with less severe or no CKD. Additional work is needed to determine the reasons for these differences.

Abstract WP312: The Association of Chronic Kidney Disease (CKD) With 30-day and 1-year Post Ischemic Stroke Mortality and Rehospitalization: Get With the Guidelines (GWTG) Stroke

Background: The extent to which CKD is associated with 30-day and 1-year post ischemic stroke mortality and rehospitalization rates has not been well studied. Methods: Data from 232,236 fee for service Medicare patients admitted with ischemic stroke to 1581 AHA GWTG-Stroke participating hospitals between January 2009 and December 2012 were analyzed. Estimated GFR in mL/min/1.73 m2 was determined based on the MDRD study equation categorized as: no CKD (GFR ≥60); stage 3a CKD (GFR 45-59); stage 3b CKD (GFR 30-44); stage 4 CKD, (GFR 15-29); stage 5 CKD (GFR &lt;15 excluding those on dialysis). Dialysis was identified by ICD-9 codes. Multivariable Cox proportional hazards models adjusted for demographics, medical history, NIHSS, arrival hour, and hospital characteristics were used to determine the independent associations of CKD (reference group those without CKD) with mortality and readmission at 30 days and 1 year. Results: After adjustment, 30-days poststroke mortality was highest among those with CKD stage 5 (HR 1.94, 95%CI 1.72-2.18), even after excluding in-hospital mortality and patients discharged to hospice (HR 2.09, 95%CI 1.66-2.63). Unadjusted 1-year mortality and readmission rates were highest among patients on dialysis (Figure). After adjustment, 1-year post-stroke mortality remained highest among patients on dialysis (HR 2.19, 95%CI 2.08-2.31), even after excluding in-hospital mortality and discharge to hospice (HR 2.65, 95%CI 2.49-2.81). For those discharged alive, 30-day and 1-year rehospitalization rates were also highest among patients on dialysis (HR 2.10, 95%CI 1.95-2.26; HR 2.55, 95%CI 2.44-2.66, respectively) as was the 30-day and 1-year composite of mortality and rehospitalization (HR 2.04, 95%CI 1.90-2.18; HR 2.46, 95% CI 2.36-2.56, respectively). Conclusion: Among Medicare beneficiaries with acute ischemic stroke, poststroke mortality and rehospitalization varied by CKD stage and were highest among those with advanced CKD.

Marker of lipid peroxidation related to diabetic nephropathy in Indonesian type 2 diabetes mellitus patients

ObjectiveEven though diabetes patients exhibit an increased oxidative stress, its correlation with diabetic nephropathy is not fully understood. The purpose of this study was to determine whether lipid peroxidation marker correlates well with eGFR and UACR in type 2 diabetes mellitus patients. MethodsWe collected urine and serum samples of Indonesian type 2 diabetes mellitus outpatients with normo- and microalbuminuria at a Local Government Clinic (from ages: 39–74 years). Urinary 8-iso-PGF2α was measured by ELISA, the serum malondialdehyde by TBARS assay, and urinary albumin by BCG albumin assay. eGFR was calculated using the corrected-Cockcroft–Gault (CG), MDRD, and CKD-EPI equation. Other necessary data were obtained through questionnaires. ResultsThe results showed that the increasing level of malondialdehyde was mildly correlated with the decline in eGFR (MDRD). In contrary, there was a significant positive correlation between 8-iso-PGF2α concentration and eGFR based on the corrected-CG, MDRD study, and CKD-EPI equation (r=0.457, p<0.001; r=0.424, p<0.001; r=0.443, p<0.001). This relationship still persisted in the normoalbuminuric subjects (n=43) (r=0.491, p=0.001; r=0.461, p=0.002; r=0.455, p=0.002). The multivariate analysis showed that 8-iso-PGF2α together with fasting plasma glucose was the most predictive factor for the high 2-quantile eGFR (adjusted OR 1.001, (95% CI, 1.000–1.001)). However, there was no significant correlation between UACR with malondialdehyde (r=0.268, p=0.050) and 8-iso-PGF2α(r=−0.030, p=0.808). UACR itself was inversely correlated with eGFR based on the corrected-CG, the MDRD, and CKD-EPI (r=−0.232, p<0.05; r=−0.228, p<0.05; r=−0.232, p<0.05). ConclusionsIncreased 8-iso-PGF2α and malondialdehyde in type 2 diabetes mellitus patients may play a role in the pathophysiologic significance of diabetic nephropathy, even while considering the effect of potential confounders.

Serum cystatin C is a determinant of central pressure augmentation index measured by oscillometric method in renal transplant recipients.

BackgroundSerum cystatin C (ScysC) may help predicting cardiovascular outcome not only through its ability to detect renal dysfunction but also through its potential connection to others factors that are directly related to cardiovascular diseases. We explored the potential association of ScysC with arterial stiffness - a major contributor to cardiovascular disease - in renal transplant recipients (RTR).MethodsTraditional and non-traditional cardio-vascular risk factors were collected from 215 stable RTR whom arterial stiffness was evaluated by the measure of the augmentation index of central pressure (AIx) determined by the arteriograph device. Serum creatinine and ScysC were measured the same day using standardized methods. Association between ScysC and AIx was examined in univariate and multivariate linear regression analysis.ResultsIn univariate analysis, ScysC was strongly associated with AIx. This relationship was not confounded by age, gender, length of time spent on dialysis and transplantation vintage. Adjustment on the level of GFR estimated by the MDRD Study equation attenuated but did not abolish the association between ScysC and AIx.ConclusionsIn conclusion, ScysC is an independent predictor of AIx in RTR. Our data suggest that arterial stiffness may partially mediate the association between ScysC and cardiovascular risk in renal transplantation.

Comparison of association of glomerular filtration rate with metabolic syndrome in a community-based population using the CKD-EPI and MDRD study equations

BackgroundTargeting metabolic syndrome (MetS) in early chronic kidney disease (CKD) is essential to reduce cardiovascular complications. We compared the association of kidney function estimated by two glomerular filtration rate (GFR) equations with MetS in community population. MethodsWe analyzed 12,700 participants from 2009 to 2010 the Korea National Health Survey data. GFR was estimated using the CKD Epidemiology Collaboration equation (GFRCKD-EPI) and the Modification of Diet in Renal Disease study equation (GFRMDRD). ResultsThe prevalence of MetS increased from the highest GFR category (>105ml/min/1.73m2) to the lowest (<60ml/min/1.73m2) using both equations (GFRCKD-EPI, 14.1% to 62.3%; GFRMDRD, 18.4% to 62.9%). Participants reclassified to higher GFRCKD-EPI category (upward) from GFRMDRD had lower prevalence of MetS than those moved downward (Net reclassification improvement 13.7%, P<0.001). Compared with GFR ≥105ml/min/1.73m2, mildly impaired GFRCKD-EPI (75–89ml/min/1.73m2) was independently associated with increased odds of MetS (OR 1.30, 95% CI 1.09–1.56, P=0.003) in multivariate analysis, whereas GFRMDRD was not (OR 1.08, 95% CI 0.92–1.27, P=0.344). ConclusionsCompared with GFRMDRD, GFRCKD-EPI showed better association with prevalence of MetS, particularly in normal to mildly impaired GFR range. GFRCKD-EPI may improve risk stratification of individuals with MetS according to kidney function in community-based population.

Abstract 19119: Augmentation Index is Associated With Renal Function in Black but Not in White Young Adults: The Bogalusa Heart Study

Background: Increased Augmentation Index (AI) has been associated with kidney damage in patients with hypertension and underlying cardio-metabolic diseases. However, information is scant on the association between AI and renal function/performance in non-institutionalized asymptomatic young adults. Hypothesis: Race-specific differences exist on the association between AI and renal function (as defined by estimated glomerular filtration rate (eGFR)), in asymptomatic young adults. Methods: As a part of the Bogalusa Heart Study, a long term community based study, 884 non-institutionalized participants with a mean age of 43.5 years (29.4-51.3), 68.3% whites and 41.9% male were considered. AI was estimated non-invasively by applanation tonometry of the radial artery. eGFR was calculated using the MDRD study equation. Race-specific independent association of AI with eGFR was tested through multivariable adjusted linear regression analyses. Results: Black participants had higher AI and eGFR levels compared to whites. Of note, black females had significantly higher levels of AI and eGFR compared to black males (p&lt;0.01). No significant sex differences were noted in white participants. In multivariable adjusted linear regression analyses, controlling for age, sex and traditional cardiovascular risk factors, AI was significantly and directly associated with eGFR in blacks (B=1.12, p&lt;0.001), but not in whites (B=0.039, p=0.34) Conclusion: The observed differences in the impact of AI on renal function help support the hypothesis that underlying mechanisms for cardiovascular disease related-end organ damage differ among race groups. Further, this may aid to enhance race-specific approaches on prevention and screening of cardiovascular disease and complications.

Prevalence of chronic kidney disease across levels of glycemia among adults in Pudong New Area, Shanghai, China

BackgroundFew population-based studies have examined the relationship between glycemic status and chronic kidney disease (CKD) in China. We examined the prevalence of CKD across categories of glycemia [diagnosed diabetes, undiagnosed diabetes (fasting plasma glucose [FPG] ≥ 126 mg/dL), prediabetes (FPG 100–126 mg/dL) and normal glycemia (FPG <100 mg/dL)] among Chinese adults and assessed the relative contribution of dysglycemia (prediabetes and/or diabetes) to the burden of CKD.Methods5,584 Chinese adults aged 20–79 years were selected from the Pudong New Area of Shanghai through a multistage random sampling. Demographic and lifestyle characteristics, anthropometry and blood pressure were measured. Biochemical assays included FPG, serum creatinine and lipids, urinary creatinine and albumin. Prevalence of albuminuria [urine albumin-to-creatinine ratio (ACR) ≥ 30 mg/g], decreased kidney function and CKD (either decreased kidney function or albuminuria) across levels of glycemia were estimated.ResultsThe prevalence of albuminuria, decreased kidney function and CKD each increased with higher glycemic levels (P < 0.001). Based on the MDRD Study equation, the unadjusted CKD prevalence was 30.9%, 28.5%, 14.1% and 9.2% in those with diagnosed diabetes, undiagnosed diabetes, prediabetes and normoglycemia, respectively. The corresponding age-, gender- and hypertension-adjusted CKD prevalence were 25.8%, 25.0%, 12.3% and 9.1%, respectively. In a multivariable analysis, the factors associated with CKD were hypertension (Odds ratio [OR] 1.70, 95% confidence interval [CI]: 1.42-2.03), dysglycemia (OR 1.65, 95% CI: 1.39-1.95), female gender (OR 1.48, 95% CI: 1.25-1.75), higher triglycerides (OR 1.14, 95% CI: 1.08-1.20 per mmol/L), higher body mass index (OR 1.08, 95% CI: 1.05-1.10 per kg/m2), and older age (OR 1.02, 95% CI: 1.01 -1.03 per year). The population attributable risks (PARs) associated with diabetes, prediabetes, dysglycemia (diabetes and prediabetes) and hypertension were 18.4%, 19.7%, 30.3% and 44.5% for CKD as defined by the MDRD study equation, and 15.8%, 24.4%, 29.2% and 10.0% with the CKD-EPI equation. Estimates of prevalence and ORs of the relative contribution of various risk factors to CKD obtained with the CKD-EPI equation were similar.ConclusionsAs much as 30% of the CKD burden may be associated with dysglycemia among Chinese adults, independent of age, gender and hypertension status. Prevention and control of diabetes and prediabetes should be a high priority in reducing the CKD burden in China.

Estimating the Glomerular Filtration Rate in the General Population Using Different Equations: Effects on Classification and Association

Background/Aims: Several formulas for glomerular filtration rate (GFR) estimation, based on serum creatinine or cystatin C, have been proposed. We assessed the impact of some of these equations on estimated GFR (eGFR) and chronic kidney disease (CKD) prevalence, and on the association with cardiovascular risk factors, in a general population sample characterized by a young mean age. Methods: We studied 1,199 individuals from three Alpine villages enrolled into the MICROS study. eGFR was obtained with the 4- and 6-parameter MDRD study equations, the Virga equation, and with the three CKD-EPI formulas for creatinine, cystatin C, and the combination of creatinine and cystatin C. We assessed the concordance between quantitative eGFR levels, CKD prevalence, and in terms of association with total, LDL, and HDL cholesterol. Results: The highest and lowest eGFR levels corresponded to the cystatin C-based and MDRD-4 equations, respectively. CKD prevalence varied from 1.8% (Virga) to 5.8% (MDRD-4). The CKD-EPI based on creatinine showed the highest agreement with all other equations. Agreement between methods was higher at lower eGFR levels, older age, and in the presence of diabetes and hypertension. Creatinine-based estimates of eGFR were associated with total and low-density lipoprotein but not high-density lipoprotein cholesterol. The opposite was observed for the cystatin C-based GFR. Conclusion: GFR estimation is strongly affected by the chosen equation. Differences are more pronounced in healthy and younger individuals. To identify CKD risk factors, the choice of the equation is of secondary importance to the choice of the biomarker used in the formula. If eGFR is not calibrated to a gold standard GFR in the general population, reports about CKD prevalence should be considered with caution.

CKD-EPI eGFR categories were better than MDRD categories for predicting mortality in a range of populations

Source Citation Matsushita K, Mahmoodi BK, Woodward M, et al; Chronic Kidney Disease Prognosis Consortium. Comparison of risk prediction using the CKD-EPI equation and the MDRD study equation for estimated glomerular filtration rate. JAMA. 2012;307:1941-51. 22570462

Risk Factors and Impact of Proximal Fixation on Acute and Chronic Renal Dysfunction After Endovascular Aortic Aneurysm Repair Using Glomerular Filtration Rate Criteria

The incidence of renal impairment relevant to proximal fixation of aortic endograft devices remains unclear. Retrospective cohort of 208 consecutive patients that underwent EVAR from 2006 to 2011. Estimated glomerular filtration rate (eGFR) was based on MDRD study equation. Acute kidney injury (AKI) and chronic kidney disease (CKD) were classified with ADIQ/RIFLE criteria and National Kidney Foundation criteria, respectively. Kaplan-Meier curve was applied to evaluate progression to CKD. Multivariate regression model was fit to identify predictors for developing AKI and CKD. Suprarenal fixation group (SF) included 110 patients and infrarenal fixation group (IF) included 98 patients. Both groups had similar demographics, baseline eGFR, and renal-protection protocols. There was a trend for decreased use of contrast in IF group (median: 93.5 vs. 103 cc, P=0.07). AKI occurred in 15% of patients in SF group and 19% of patients in IF group (RR: 1.24, P=0.47). The freedom from progression to stage 3 or 4 CKD in the SF group was 0.76, 0.72, and 0.49 at 6, 12, and 18 months, respectively, while for IF group was 0.8, 0.73, and 0.68, respectively (P=0.4). Increasing age (P=0.07), lengthy procedures (P<0.001), and baseline renal dysfunction (P<0.001) were significant predictors for developing CKD. Contrast volume (P<0.001) and ace-inhibitors (P=0.07) were predictors for AKI. Proximal fixation type has no significant effect on both acute and chronic renal function. Identification of modifiable perioperative risk factors may be used to improve renal function outcomes.

Estimating glomerular filtration rate (GFR) in diabetes: The performance of MDRD and CKD-EPI equations in patients with various degrees of albuminuria

ObjectivesThe aim of this study was to compare the performance of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease Study (MDRD) equations in estimating GFR in a large cohort of diabetic patients with various degrees of albuminuria. Design and methodsIn a group of 842 diabetic patients GFR was estimated from standardized creatinine, with MDRD-Study and CKD-EPI equations, and their performance evaluated regarding clinical stages of albuminuria and chronic kidney disease (CKD). ResultsPatients with normoalbuminuria had higher eGFR when calculated by CKD-EPI, than MDRD-Study equation [median (IQR): 103 (91–115) vs 97 (85–113)mL/min/1.73m2, P=0.006, n=364], which significantly influenced the prevalence of stage 1 CKD [eGFR>90mL/min/1.73m2: 76.7% (CKD-EPI) vs. 65.1% (MDRD-Study), P=0.005]. There were no differences between the eGFR values derived by two equations in patients with micro- and macroalbuminuria, and more advanced staging of CKD. ConclusionCKD-EPI equation might be a superior surrogate marker of GFR in patients with normoalbuminuria and hyperfiltration and could be used as a screening tool for early renal impairment in diabetes. It's validity as a marker of progression of diabetic nephropathy merits further investigation.