For the KNOW-CKD study, investigators led by Kyu Hun Choi, MD, of Inje University, Pusan Paik Hospital in Busan, Korea, assessed anemia, albuminuria, and eGFR in 1,456 CKD patients. The average eGFR was 51.9 mL/min/1.73m2 and urinary albumin-to-creatinine ratio (ACR) was 853.2 mg/g. Forty-one percent of patients had anemia.
Anemia increased along with ACR, according to results published in PLOS One. The odds of anemia were 43% higher in patients with ACR 30–299 mg/g and 86% higher with ACR 300 mg/g and above. Adjustments were made for factors such as eGFR, age, body mass index, cause of CKD, and use of erythropoiesis-stimulating agents. Researchers further observed graded associations for macroalbuminuria at various eGFRs compared with normal ACR (less than 30 mg/g) and eGFR 60 mL/min/1.73m2 and above. Microalbuminuria showed no association with anemia.
The findings are additional evidence supporting the CGA staging system (the cause, GFR, and albuminuria) by Kidney Disease: Improving Global Outcomes (KDIGO), according to the researchers. Since this was a cross-sectional study, however, they were not able to determine the nature of the relationship between albuminuria and anemia.