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Background: Few studies have examined the impact of chronic kidney disease (CKD) on adverse cardiovascular outcomes and deaths in Asian populations. We evaluated the associations of CKD with cardiovascular disease (CVD) and all-cause mortality in a multi-ethnic Asian population., Design: Prospective cohort study of 7098 individuals who participated in two independent population-based studies involving Malay adults (n = 3148) and a multi-ethnic cohort of Chinese, Malay and Indian adults (n = 3950)., Methods: CKD was assessed from CKD-EPI estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR). Incident CVD (myocardial infarction, stroke and CVD mortality) and all-cause mortality were identified by linkage with national disease/death registries., Results: Over a median follow-up of 4.3 years, 4.6% developed CVD and 6.1% died. Risks of both CVD and all-cause mortality increased with decreasing eGFR and increasing albuminuria (all p-trend <0.05). Adjusted hazard ratios (HR (95% confidence interval)) of CVD and all-cause mortality were: 1.54 (1.05-2.27) and 2.21 (1.67-2.92) comparing eGFR <45 vs ≥60; 2.81 (1.49-5.29) and 2.34 (1.28-4.28) comparing UACR ≥300 vs <30. The association between eGFR <60 and all-cause mortality was stronger among those with diabetes (p-interaction = 0.02). PAR of incident CVD was greater among those with UACR ≥300 (12.9%) and that of all-cause mortality greater among those with eGFR <45 (16.5%)., Conclusions: In multi-ethnic Asian adults, lower eGFR and higher albuminuria were independently associated with incident CVD and all-cause mortality. These findings extend previously reported similar associations in Western populations to Asians and emphasize the need for early detection of CKD and intervention to prevent adverse outcomes., (© The European Society of Cardiology 2014.)

Background: Obesity is associated with diabetes and hypertension, two major risk factors for chronic kidney disease (CKD). Recently, it has been shown that obesity is associated with preclinical kidney disease defined by elevated levels of cystatin C among those without CKD in US adults. However, the association of obesity with cystatin C is not known in industrialized Asian populations., Methods: We examined 2,052 Indian adults aged 40-80 years in Singapore who were free of CKD defined as a serum creatinine-based estimated glomerular filtration rate (eGFRcr) <60 mL/min/1.73 m(2) and/or the presence of microalbuminuria. Body mass index (BMI) values were categorized into normal (18.5-24.9), overweight (25-29.9) and obese (≥30 kg/m(2)). Elevated serum cystatin C was defined as cystatin C ≥1 mg/L., Results: Overweight and obesity were significantly associated with elevated levels of cystatin C after adjusting for potential confounders including diabetes and hypertension and eGFRcr. Compared to those with normal weight, the odds ratio (95 % confidence interval) of elevated cystatin C was 1.49 (1.17-1.88) for overweight and 3.20 (2.33-4.39) for obese. This association was consistently present when BMI was analyzed as a continuous variable and also in subgroups of men, women and in those without diabetes mellitus or hypertension., Conclusions: Higher BMI levels are associated with preclinical kidney disease in Indian adults aged 40 years and above without CKD.

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.

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.

Background: Clinical practice guidelines recommend objective nutritional assessments in managing chronic kidney disease (CKD) patients but were developed while referencing to a North-American population. Specific recommendations for assessing muscle mass were suggested (mid-arm circumference, MAC; corrected mid-arm muscle area, cAMA; mid-arm muscle circumference, MAMC). This study aimed to assess correlation and association of these assessments with dietary protein intake in a multi-ethnic Asian population of healthy and CKD patients., Methods: We analyzed 24-hour urine collections of selected participants to estimate total protein intake (TPI; g/day). Ideal body weight (IDW; kg) was calculated and muscle assessments conducted. Analyses involved correlation and linear regression, taking significance at p<0.05., Results: There were 232 stable CKD patients and 103 healthy participants comprising of 51.0% male, 38.5% Chinese, 29.6% Malay, 23.6% Indian, and 8.4% others. The mean TPI was 58.9 ± 18.4 g/day in healthy participants and 53.6 ± 19.4 g/day in CKD patients. When normalized to ideal body weight, TPI-IDW (g/kg/day) was similar in healthy and CKD participants. Overall, TPI was associated with MAC (r=0.372, p<0.001), cAMA (r=0.337, p<0.001), and MAMC (r=0.351, p<0.001). TPI-IDW was also associated with MAC (r=0.304, p<0.001), cAMA (r=0.202, p<0.001), and MAMC (r=0.200, p<0.001) but not for TPI normalized to actual body weight. When examined separately, TPI was associated with MAC, cAMA, and MAMC in both CKD and healthy participants, but was associated with TPI-IDW only in CKD patients., Conclusion: Total protein intake was associated with muscle assessments in all participants. TPI normalized to IDW should only be used in CKD patients.

Background: Chronic kidney disease (CKD) is an emerging public health problem worldwide. Previous studies have shown an association between blood pressure (BP) and CKD. However, it is not clear if there are ethnic differences in this association. We examined the association between BP and CKD in a multi-ethnic Asian population in Singapore., Methods: We analysed data from three large population-based studies conducted between 2004-2011, (n=3,167 Chinese, 3,082 Malays and 3,228 Indians) aged 40-80 years. CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m² from serum creatinine. Hypertension was defined as a self-reported current use of antihypertensive medication or systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg. We also analysed the association of CKD with individual BP components., Results: The prevalence of both hypertension and CKD was higher among Malays (68.6, 21%) compared to Chinese (57.9, 5.9%) and Indians (56.0, 7.4%), but treatment for hypertension was lower among Malays (53.4%) compared to Chinese (89.8%) and Indians (83.1%). Hypertension was associated with CKD in all three ethnic groups (OR [95% CI] = 2.71 [1.59-4.63], 2.08 [1.62-2.68], 2.43 [1.66-3.57] in Chinese, Malays and Indians). Among the BP components, both systolic and diastolic BP were associated with CKD in Malays whereas, systolic BP was not significantly associated with CKD, and diastolic BP showed an inverse association which was explained by anti-hypertensive medication use in Chinese and Indians., Conclusions: Hypertension was associated with CKD in Chinese, Malays and Indians. However, the BP components were associated with CKD only in Malays.

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.)