Anemia burden increases with chronic kidney disease (CKD) stage and may be undertreated, a new study finds.

Investigators led by Danielle K. Farrington, MD, MHS, of Johns Hopkins University in Baltimore, Maryland, characterized anemia prevalence in the United States during a contemporary era (2016-2019) using data from 5,004,957 individuals in the Optum Labs Data Warehouse. Low estimated glomerular filtration rate (eGFR) correlated with severe anemia (hemoglobin level less than 10 g/dL) in both men and women. Severe anemia affected 1.3%, 3.1%, 7.5%, 17.4%, and 29.7% of men and 1.9%, 3.9%, 8.6%, 19.4%, and 37.6% of women in eGFR categories of 60-74, 45-59, 30-44, 15-29, and less than 15 mL/min/1.73 m2, respectively, the investigators reported in the American Journal of Kidney Diseases. Older age and Black race also was associated with anemia.

Few patients overall were tested for iron deficiency, including 15.6% of men and 19.6% of women. Among those with anemia who had iron studies, 69.9% had low transferrin saturation (TSAT) and 76.4% had low ferritin. Iron deficiency was more prevalent with CKD. Among patients with anemia and an eGFR less than 15 mL/min/1.73 m2, only 40.1% of men and 50.5% of women had iron testing. According to Dr Farrington and colleagues, iron testing and potentially iron supplementation should increase.

Continue Reading

Overall use of erythropoiesis-stimulating agents (ESA) was less than 4%.

Anemia was independently associated with adverse outcomes, the investigators reported. Among men and women with a hemoglobin level less than 9 g/dL, they found a significant 1.4- and 1.6-fold increased risk for requiring kidney replacement therapy, a 2.1- and 1.9-fold increased risk for cardiovascular disease, a 1.6- and 1.7-fold increased risk for coronary heart disease, a 1.6- and 1.6-fold increased risk for stroke, a 2.2- and 2.0-fold increased risk for heart failure, and a 2.9- and 2.5-fold increased risk for death, respectively. Low iron did not worsen the risks for these outcomes.

“Future studies should investigate safe strategies to mitigate the risks associated with anemia in CKD,” Dr Farrington’s team concluded.


Farrington DK, Sang Y, Grams ME, et al. Anemia prevalence, type, and associated risks in a cohort of 5.0 million insured patients in the United States by level of kidney function. Am J Kidney Dis. 2023 Feb;81(2):201-209.e1. doi:10.1053/j.ajkd.2022.07.014