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The National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines recommended the Modification of Diet in Renal Disease study equation for estimating glomerular filtration rate (GFR) for the classification of CKD, but its accuracy was limited to North American patients with estimated GFR <60 mL/min per 1.73 m 2 body surface area of European (White) or African (Black) descent. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) developed another equation for estimating GFR, derived from a population that included both participants without kidney disease and with CKD. But many ethnicities were inadequately represented. The International Society of Nephrology, Kidney Disease Improving Global Outcomes committee promulgated clinical practice guidelines, which recommended the CKD-EPI equation. Investigators in Asia subsequently assessed the performance of these GFR estimating equations-the Modification of Diet in Renal Disease study equation, the CKD-EPI equation (creatinine only), and the CKD-EPI equations (creatinine and cystatin C). In this review, we summarize the studies performed in Asia on validating or establishing new Asian ethnicity GFR estimating equations. We included both prospective and retrospective studies which used serum markers traceable to reference materials and focused the review of the performance of GFR estimation by comparisons with the GFR estimations obtained from the CKD-EPI equations., (Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: Clinical practice guidelines recommend using creatinine-based equations to estimate glomerular filtration rates (GFRs). While these equations were formulated for Caucasian-American populations and have adjustment coefficients for African-American populations, they are not validated for other ethnicities. The Chronic Kidney Disease-Epidemiology Collaborative Group (CKD-EPI) recently developed a new equation that uses both creatinine and cystatin C. We aimed to assess the accuracy of this equation in estimating the GFRs of participants (healthy and with chronic kidney disease [CKD]) from a multiethnic Asian population., Methods: Serum samples from the Asian Kidney Disease Study and the Singapore Kidney Function Study were used. GFR was measured using plasma clearance of 99mTc-DTPA. GFR was estimated using the CKD-EPI equations. The performance of GFR estimation equations were examined using median and interquartile range values, and the percentage difference from the measured GFR., Results: The study comprised 335 participants (69.3% with CKD; 38.5% Chinese, 29.6% Malays, 23.6% Indians, 8.3% others), with a mean age of 53.5 ± 15.1 years. Mean standardised serum creatinine was 127 ± 86 μmol/L, while mean standardised serum cystatin C and mean measured GFR were 1.43 ± 0.74 mg/L and 67 ± 33 mL/min/1.73 m2, respectively. The creatinine-cystatin C CKD-EPI equation performed the best, with an estimated GFR of 67 ± 35 mL/min/1.73 m2., Conclusion: The new creatinine-cystatin C equation estimated GFR with little bias, and had increased precision and accuracy in our multiethnic Asian population. This two-biomarker equation may increase the accuracy of population studies on CKD, without the need to consider ethnicity.

Aim: The Chronic Kidney Disease Collaboration - Epidemiology (CKD-EPI) glomerular filtration rates (GFR) estimation equation is believed to estimate GFR more accurately in healthy people but this has not been validated in Asians. We studied the distribution of GFR in a multi-ethnic Asian population without CKD, and compared the performance of measures of GFR estimation, including the CKD-EPI equation, Cockroft-Gault equation, and 24-hour urine creatinine clearances., Materials and Methods: A total of 103 healthy volunteers without a history of kidney disease, hypertension, or diabetes underwent GFR measurement using 3-sample plasma clearance of (99m) Tc-DTPA. Cockroft-Gault estimated GFR and 24-hour urine creatinine clearances were normalized to body surface area., Results: The mean measured GFR was 101 ± 15.8 mL/min per 1.73 m(2) and was lowest in Indians (93 ± 12.3 mL/min per 1.73 m(2); P < 0.001). The CKD-EPI equation appears to be more accurate for healthy participants. Estimated GFR correlated with measured GFR (r = 0.57, P < 0.001), and the mean difference is 3.72 ± 14.43 mL/min per 1.73 m(2) (P < 0.001). However, estimating GFR using self-directed 24-hour urine creatinine clearances is poorer than using the CKD-EPI equation., Conclusions: GFR estimation using self-directed 24-hour urine collection for creatinine clearance is less accurate than using the CKD-EPI equation. A larger study is required to clarify GFR in healthy Asians, and the association of health outcomes of Asian kidney donors with lower GFR thresholds., (© 2013 Asian Pacific Society of Nephrology.)

Purpose: Accurate assessment of kidney function is critical to evaluate living kidney donors. Direct glomerular filtration rate measurement using isotopes is currently the gold standard but it is complex and costly. We evaluated the performance of surrogate markers of the glomerular filtration rate in living kidney donors by comparing direct measurement of the rate to the creatinine based equation estimated rate, the kidney volume based estimated rate using a newly developed equation and creatinine clearance., Materials and Methods: We first statistically compared direct glomerular filtration rate measurement to the results of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) creatinine based equations, and to creatinine clearance in 54 potential renal donors from 2006 to 2010. In 32 donors with cross-sectional computerized tomography available we used measured functional renal volume with age, gender, weight and serum creatinine to estimate the rate based on kidney volume according to a previously reported model. Kidney volume based measurement was compared to direct glomerular filtration rate measurement and assessed against the results of the best performing creatinine based equation., Results: In the first group of 54 donors the correlation index of the estimated glomerular filtration rate according to MDRD and CKD-EPI creatinine based equations, and to creatinine clearance was low compared to direct measurement. In the subset of 32 potential donors the kidney volume based estimated rate correlated better with direct measurement than MDRD equation results with higher accuracy (estimated 87.5% and 75.0% within 30% and 10% of direct rate measurement, respectively)., Conclusions: To estimate the glomerular filtration rate in healthy individuals a volume based model correlated better than the MDRD equation, which is the best performing creatinine based equation used to estimate the rate. By providing a more robust estimation of the glomerular filtration rate in healthy potential kidney donors, the volume based model adds value to routine preoperative computerized tomography above that of anatomical evaluation., (Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

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.

Background: Clinical practice guidelines recommend using equations for estimating glomerular filtration rate (GFR) in chronic kidney disease (CKD) management and research. The MDRD (Modification of Diet in Renal Disease) Study and CKD-EPI (CKD Epidemiology Collaboration) equations originally were derived from a North American population and had an ethnic coefficient adjustment for African Americans. A Chinese coefficient for the MDRD Study equation subsequently was determined, but this has not been externally validated. We compared the accuracy of the equations, evaluated the ethnic coefficients, and assessed the equations for disease staging in a multiethnic Asian population with CKD., Study Design: A diagnostic test study comparing the Asian coefficient (and subgroups)-modified MDRD Study and CKD-EPI equations and a cross-sectional study assessing disease staging., Setting & Participants: 232 outpatients (52% men; 40.5% Chinese, 32% Malay, and 27.5% Indian/other) with stable CKD., Index Test: Asian and ethnicity-based modifications of the MDRD Study and CKD-EPI equations., Reference Test: Measured GFR using 3-sample plasma clearance of technetium-99m diethylenetriaminepentaacetic acid ((99m)Tc-DTPA), calculated using the slope-intercept method, with body surface area normalization (du Bois) and Brochner-Mortensen correction., Results: Overall, the CKD-EPI equation is more accurate than the MDRD Study equation throughout the GFR range, with improved bias (median difference of estimated GFR - measured GFR) and root mean square error (P <0.001). CKD-EPI versus MDRD Study equation: bias, 1.1 ± 13.8 vs -1.0 ± 15.2 mL/min/1.73 m(2); precision, 12.1 vs 12.2 mL/min/1.73 m(2). Ethnic coefficients did not improve estimates of GFR significantly. The correctness of staging was improved using the CKD-EPI equation., Limitations: All participants had CKD, but few were of European descent. The reference GFR technique was different from the original studies., Conclusions: The CKD-EPI is more accurate than the MDRD Study equation, particularly at higher GFRs. Therefore, we recommend adopting the CKD-EPI equation without ethnic adjustment for estimating GFR in multiethnic Asian patients with CKD., (Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: Clinical practice guidelines recommend different blood pressure (BP) goals for chronic kidney disease (CKD) patients. Usage of antihypertensive medication and attainment of BP targets in Asian CKD patients remain unclear. This study describes the profile of antihypertensive agents used and BP components in a multiethnic Asian population with stable CKD.Methods: Stable CKD outpatients with variability of serum creatinine levels < 20%, taken > 3 months apart, were recruited. Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using automated manometers, according to practice guidelines. Serum creatinine was assayed and the estimated glomerular filtration rate (GFR) calculated using the CKD Epidemiology Collaboration equation. BP and antihypertensive medication profile was examined using univariate analyses.Results: 613 patients (55.1% male; 74.7% Chinese, 6.4% Indian, 11.4% Malay; 35.7% diabetes mellitus) with a mean age of 57.8 ± 14.5 years were recruited. Mean SBP was 139 ± 20 mmHg, DBP was 74 ± 11 mmHg, serum creatinine was 166 ± 115 µmol/L and GFR was 53 ± 32 mL/min/1.73 m(2). At a lower GFR, SBP increased (p < 0.001), whereas DBP decreased (p = 0.0052). Mean SBP increased in tandem with the number of antihypertensive agents used (p < 0.001), while mean DBP decreased when ≥ 3 antihypertensive agents were used (p = 0.0020).Conclusion: Different targets are recommended for each BP component in CKD patients. A majority of patients cannot attain SBP targets and/or exceed DBP targets. Research into monitoring and treatment methods is required to better define BP targets in CKD patients. [ABSTRACT FROM AUTHOR]

Background Current literature reports improvement in kidney function in obese patients after bariatric surgery in non-Asian centers. It is unclear how kidney function is affected by postoperative body composition changes in obese Asian patients. Objectives To evaluate kidney function and its relationship to body composition in a multiethnic Asian population after bariatric surgery. Setting This study was performed in a university hospital. Methods Data of 68 obese patients who were followed for 1 year after surgery were retrieved from our university hospital clinical care database. Body composition was obtained by bioimpedance analysis. Kidney function was calculated as glomerular filtration rate (GFR) using the following formulas: (1) Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) (estimated GFR [eGFR], mL/min/1.73 m 2 ); (2) absolute GFR (aGFR, mL/min); and (3) lean weight–adjusted Cockcroft-Gault creatinine clearance (CG-LBW, mL/min). Patients were further examined by 2 subgroups: eGFR<90 and>90 mL/min/1.73 m 2 . Results One year after surgery, body mass index (BMI) declined from 41.9±5.7 to 29.6±4.2 kg/m 2 ( P <.001), body surface area (BSA) decreased from 2.15±0.23 to 1.86±0.18 m 2 ( P <.001), and fat mass (FM) reduced from 45.8±9.4 to 25.6±10.5 kg ( P <.001). There were significant differences in percentage excess weight loss (%EWL) among Chinese, Malays, Indians, and other ethnicities. Similar results were found with percentage fat mass loss (%FML). Changes in aGFR were associated with reductions in FM ( P = .010), BSA ( P = .049), and %EWL ( P <.001). In the eGFR>90 subgroup, eGFR decreased from 143±22 to 122±19 mL/min/1.73 m 2 . Conversely, in the eGFR<90 subgroup, eGFR had a trend of improvement from 69 to 79 mL/min/1.73 m 2 . Conclusion Changes in eGFR after bariatric surgery in the obese Asian patient are strongly associated with reduction in FM, BSA, and %EWL. More work is required to investigate if certain ethnicities have better postoperative renal profiles. [ABSTRACT FROM AUTHOR]

Background: Adiponectin and leptin, two of the key cytokines secreted by adipocytes, have been shown to be associated with cardiovascular disease. However, the association of these adipocytokines with chronic kidney disease (CKD) is not clear. We examined the association of serum adiponectin, leptin levels and leptin to adiponectin ratio (LAR) with CKD in a population-based sample of Asian adults. Methods: We conducted a case-control study (450 CKD cases and 920 controls matched for age, sex and ethnicity) involving Chinese and Indian adults aged 40–80 years who participated in the Singapore Epidemiology of Eye Diseases Study (2007–2011). CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73m2 from serum creatinine. Serum adiponectin and leptin levels were measured using commercially available ELISA. Odds ratio of CKD associated with elevated adiponectin and leptin levels were estimated using logistic regression models adjusted for age, gender, ethnicity, education, smoking, body mass index, diabetes, blood pressure, total and HDL cholesterol. Results: CKD cases had higher levels of leptin (mean [SD] 9.7 [11.5] vs.16.9 [20.2] ng/mL, p<0.0001) and adiponectin (10.4 [7.4] vs. 9.2 [4.2], p = 0.001) compared to controls. In multi-variable models, compared to those in the lowest quartile, the OR (95% confidence interval) of CKD among those in the highest quartile were: 6.46 (3.84, 10.88), 1.94 (1.32–2.85) and 2.88 (1.78–4.64) for leptin, adiponectin and LAR. Similar associations were also observed when adiponectin and leptin were analyzed as continuous variables. This positive association of serum adiponectin, leptin and LAR with CKD was consistently present in subgroups of gender, ethnicity, diabetes, hypertension and overweight status (all P-interaction >0.1). Conclusions: Higher levels of serum adiponectin, leptin and LAR were positively associated with CKD independent of traditional risk factors in this Asian population. [ABSTRACT FROM AUTHOR]

Background. The use of spot urine protein to creatinine ratios in estimating 24 hr urine protein excretion rates for diagnosing and managing chronic kidney disease (CKD) predated the standardization of creatinine assays. The comparative predictive performance of spot urine ratios and 24 hr urine collections (of albumin or protein) for the clinical outcomes of CKD progression, end-stage renal disease (ESRD), and mortality in Asians is unclear. We compared 4 methods of assessing urine protein excretion in a multiethnic population of CKD patients. Methods. Patients with CKD (n=232) provided 24 hr urine collections followed by spot urine samples the next morning. We created multiple linear regression models to assess the factors associated with GFR decline (median follow-up: 37 months, IQR 26–41) and constructed Cox proportional-hazards models for predicting the combined outcome of ESRD and death. Results. The linear regression models showed that 24 hr urine protein excretion was most predictive of GFR decline but all other methods were similar. For the combined outcomes of ESRD and death, the proportional hazards models had similar predictive performance. Conclusions. We showed that all methods of assessments were comparable for clinical end-points, and any method can be used in clinical practice or research. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To examine the ethnic differences in the association between metabolic syndrome components and CKD in Asian populations. Methods: We analyzed data from three independent populations in Singapore representing the three major Asian ethnic groups (n =3167 Chinese, 3082 Malays and 3228 Indians) aged 40–80 years. CKD was defined as an estimated glomerular filtration rate <60mL/min/1.73m2. Factor analysis of metabolic syndrome components was conducted and factor scores were used as independent variables in multivariable logistic regression models. Results: The prevalence of CKD was highest among Malays (21.0% vs. 7.4%, 5.9% in Indians and Chinese). Factor analysis identified three factors among Chinese (glycemia, blood pressure [BP], and obesity/lipid) and Malays (glycemia, BP, and lipids) accounting for 70% of the variance and four factors (glycemia, BP, lipids, and obesity) among Indians accounting for 82% of the variance. Glycemia was positively associated with CKD in all three ethnic groups. BP was positively associated with CKD among Malays (OR [95% CI] of 1.16 [1.06–1.28]), whereas it showed an inverse association among Chinese (0.84 [0.71–0.99]) and Indians (0.84 [0.73–0.97]). However, this inverse association lost significance after adjusting for antihypertensive medication use in Chinese and Indians. Obesity/lipids among Chinese and obesity among Indians showed a positive association; lipids showed an inverse association among Malays. Conclusions: These data suggest that while hyperglycemia was associated with CKD in all three ethnic groups, the impact of BP, lipids, obesity on CKD varies across ethnic groups. Understanding the specific associations may allow greater understanding of how CKD develops in different racial/ethnic groups. [Copyright &y& Elsevier]

AFCKDI RECOMMENDATIONS FOR EARLY DETECTION OF CHRONIC KIDNEY DISEASE 1. Targets Patients with diabetes, hypertension Those with family history of chronic kidney disease (CKD) Individuals receiving potentially nephrotoxic drugs, herbs or substances or taking indigenous medicine Patients with past history of acute kidney injury Individuals older than 65 years 2. Tools Spot urine sample for protein with standard urine Dipstick test (need a repeat confirmatory test if positive) Dipstick for red blood cells (need confirmation by urine microscopy) An estimate of glomerular filtration rate based on serum creatinine concentration 3. Frequency of screening Screening frequency for targeted individuals should be yearly if no abnormality is detected on initial evaluation. 4. Who should perform the screening Doctors, nurses, paramedical staff and other trained healthcare professionals 5. Intervention after screening Patients detected to have CKD should be referred to primary care physicians with experience in management of kidney disease for follow up. A management protocol should be provided to the primary care physicians. Further referral to nephrologists for management will be based on the protocol together with clinical judgment of the primary care physicians with their assessment of the severity of CKD and the likelihood of progression. 6. Screening for cardiovascular disease risk It is recommended that cardiovascular disease risk factors should be screened in all patients with CKD. [ABSTRACT FROM AUTHOR]

The article discusses a study which examined serum high-sensitivity troponin concentrations in a multi-ethnic Asian population with stable chronic kidney disease. Topics covered include the cardiac effect of elevated troponins in CKD, the use of a high-sensitivity assay in the study, and basic characteristics of the study participants.