The association of chronic kidney disease complications by albuminuria and glomerular fltration rate: A cross-sectional analysis

Abstract

Background: Albuminuria is strongly associated with future risk for cardiovascular and kidney outcomes, and has been proposed to be included in the classif-cation of chronic kidney disease (CKD) along with glomerular fltration rate (GFR). Few data are available on whether albuminuria is associated with concurrent complications of CKD. Methods: A cross-sectional analysis of 1,665 participants screened for the Modi-fcation of Diet in Renal Disease (MDRD) study was performed to examine the association between albuminuria (determined using urine albumin-creatinine ratio (ACR)) and measured GFR (determined using urinary clearance of iothalamate) with anemia, acidosis, hyperphosphatemia, and hypertension. Results: Mean GFR (± SD) was 39 ml/ min/1.73 m2 (± 21) and the median (25 - 75th percentile) ACR was 161 (38 - 680) mg/g. In multivariable models adjusted for age, sex, race, kidney disease etiology, and GFR, higher ACR levels were not associated with any complication. For example, comparing ACR > 300 mg/g vs. < 30 mg/g, the prevalence ratio (95% CI) for anemia was 0.98 (0.81 - 1.20), acidosis 1.13 (0.86 - 1.48), hyperphosphatemia 1.69 (0.91 - 3.17), and hypertension 1.04 (0.97 - 1.12). Lower levels of GFR were associated with all complications. For example, GFR levels < 30 ml/ min/1.73 m2 vs. GFR levels 60 - 89 ml/ min/1.73 m2 were associated with prevalence ratios (95% CI) of anemia 4.35 (3.18 - 5.96), acidosis 5.31 (3.41 - 8.29), hyperphospha-temia 23.8 (7.71 - 73.6), and hypertension 1.21 (1.10 - 1.32). Conclusions: Albumin-uria is not associated with complications after controlling for GFR in patients younger than 70 years of age with non-diabetic CKD and GFR less than 90 ml/min/1.73 m2 and thus would not affect clinical action plans for decisions regarding evaluation and treatment of complications in similar populations. ©2013 Dustri-Verlag Dr. K. Feistle.