Anemia in patients with chronic kidney disease (CKD) portends an increased risk for dementia, investigators report.

Among 620,095 US veterans with stage G3 CKD, 92,306 (15%) veterans developed dementia over a median 4.1 years before progressing to kidney failure or death. At the time of CKD diagnosis, mean age was 72 years. Men accounted for 97% of the cohort and women 3%.

Anemia in the 2 years before CKD diagnosis was categorized as normal, mild, or moderate/severe hemoglobin levels of 12.0 or more, 11.0-11.9, or less than 11.0 g/dL in women, respectively, and 13.0 or more, 11.0-12.9, or less than 11.0 g/dL in men, respectively.

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In multivariable-adjusted models, dementia risk was significantly increased 16% and 27% in veterans with mild and moderate/severe anemia, respectively, compared with veterans with no anemia, Alain K. Koyama, ScD, of the Centers for Disease Control and Prevention in Atlanta, Georgia, and colleagues reported in the American Journal of Kidney Diseases. Adjusting for iron deficiency using transferrin saturation and use of erythropoiesis-stimulating agents (ESA) did not alter results. Time-varying anemia showed even stronger associations with the endpoint.

The risk for a composite of kidney failure or death was significantly increased 1.4- and 2.2-fold among veterans with mild and moderate/severe anemia, respectively, the investigators further reported.

Whether anemia contributes to dementia risk remains an open question. Reduced oxygenation of brain tissue might increase production of β-amyloid protein, Dr Koyama’s team noted. However, dementia can also lead to cognitive impairment resulting in malnutrition and thereby anemia. A myriad of other associations could underlie the anemia-dementia association.

“Future studies are warranted to identify what factors leading to anemia play the largest role in the etiology of dementia. Identification of modifiable risk factors would have the greatest potential public health impact in reducing dementia risk among adults with CKD.”


Koyama AK, Nee R, Yu W, et al. Role of anemia in dementia risk among veterans with incident CKD. Am J Kidney Dis. Published online July 27, 2023. doi:10.1053/j.ajkd.2023.04.013