Association of race/ethnicity, inflammation, and albuminuria in patients with diabetes and early chronic kidney disease

Abstract

OBJECTIVE: African Americans (AAs) and Hispanics have higher diabetes and end-stage renal disease but similar or lower early chronic kidney disease (CKD) compared with whites. Inflammation plays a critical role in the pathogenesis of diabetes-related CKD. We postulated that in contrast to the general population, AAs and Hispanics have a higher prevalence of early diabetic CKD and systemic inflammatory markers compared with whites. RESEARCH DESIGN AND METHODS: We analyzed the National Health and Nutrition Examination Survey 1999-2008 of 2,310 diabetic patients aged ≥20 years with fasting plasma glucose (FPG) ≥126 mg/dL. We performed multiple linear regression among patients with early CKD (urinary albumin excretion [UAE] ≥30 μg/mL and estimated glomerular filtration rate ≥60 mL/min/1.73 m2) to test the relationship between UAE and C-reactive protein (CRP) by race/ethnicity, adjusting for demographics, diabetes duration, FPG, hemoglobin A1c, uric acid, white blood cell count, medication use, cardiovascular disease, and related parameters. RESULTS: In patients with diabetes, the prevalence of early CKD was greater among Hispanics and AAs thanwhites (P < 0.0001). AAs had higher adjusted odds ratio (AOR) for CRP ≥0.2 mg/dL (AOR 1.81 [95% CI 1.19-2.78]), and Hispanics had higher AOR for UAE ≥30 μg/mL (AOR 1.65 [1.07-2.54]). In a regression model adjusted for confounding variables, there was a significant association between UAE and CRP in the mid-CRP tertile (CRP 0.20-0.56 mg/dL, P = 0.001) and highest CRP tertile (CRP ≥0.57 mg/dL, P = 0.01) for Hispanics, but only in the mid-CRP tertile (P = 0.04) for AAs, compared with whites. CONCLUSIONS: AAs and Hispanics with diabetes have a higher prevalence of early CKD compared with whites, which is significantly associated with UAE and/or CRP. © 2014 by the American Diabetes Association.