Incidence and Progression of Chronic Kidney Disease in Black and White Individuals with Type 2 Diabetes

Abstract

Background and objectives: Type 2 diabetes and associated CKD disproportionately affect blacks. It is uncertain if racial disparities in type 2 diabetes-associated CKD are driven by biologic factors that influence propensity to CKD or by differences in type 2 diabetes care.

Design, setting, participants, & measurements: We conducted a post hoc analysis of 1937 black and 6372 white participants of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial to examine associations of black race with change in eGFR and risks of developing microalbuminuria, macroalbuminuria, incident CKD (eGFR<60 ml/min per 1.73m², ≥25% decrease from baseline eGFR, and eGFR slope <-1.6 ml/min per 1.73 m² per year), and kidney failure or serum creatinine >3.3 mg/dl.

Results: During a median follow-up that ranged between 4.4 and 4.7 years, 278 black participants (58 per 1000 person-years) and 981 white participants (55 per 1000 person-years) developed microalbuminuria, 122 black participants (16 per 1000 person-years) and 374 white participants (14 per 1000 person-years) developed macroalbuminuria, 111 black participants (21 per 1000 person-years) and 499 white participants (28 per 1000 person-years) developed incident CKD, and 59 black participants (seven per 1000 person-years) and 178 white participants (six per 1000 person-years) developed kidney failure or serum creatinine >3.3 mg/dl. Compared with white participants, black participants had lower risks of incident CKD (hazard ratio, 0.73; 95% confidence intervals, 0.57 to 0.92). There were no significant differences by race in eGFR decline or in risks of microalbuminuria, macroalbuminuria, and kidney failure or of serum creatinine >3.3 mg/dl.

Conclusions: Black participants enrolled in a randomized controlled trial had lower rates of incident CKD compared with white participants. Rates of eGFR decline, microalbuminuria, macroalbuminuria, and kidney failure did not vary by race.

Keywords: Biological Factors; Cardiovascular Diseases; Confidence Intervals; Diabetes Mellitus, Type 2; Disease Progression; Follow-up Studies; Humans; Incidence; Renal Insufficiency; Renal Insufficiency, Chronic; chronic kidney disease; creatinine; diabetes; glomerular filtration rate; risk factors.