ATLANTA — What is the role of anemia in risk of dementia in veterans with chronic kidney disease?
That was the question raised in a recent report in the American Journal of Kidney Disease. “While some evidence exists of increased dementia risk from anemia, it is unclear if this association persists among adults with CKD,” the authors wrote. “Anemia may be a key marker for dementia among adults with CKD. We therefore evaluated if anemia is associated with an increased risk of dementia among adults with CKD.”
The retrospective cohort study was conducted by a team of researchers from the national Centers for Disease Control and Prevention in Atlanta, the Walter Reed National Military Medical Center and Uniformed Services University, both in Bethesda, MD, and VAMCs in Salem, VA, and Salt Lake City, as well as academic institutions.
The study included 620,095 veterans aged 45 and older with incident Stage 3 CKD, defined as an estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2), between January 2005 and December 2016. The analysis of VHA data, which included follow-up until the end of 2018, focused on incident dementia, kidney failure or death.
The study assessed anemia based on the average of hemoglobin levels (g/L) during the two years prior to the date of incident CKD and categorized as normal, mild and moderate/severe anemia—(≥12.0, 11.0-11.9, <11.0 g/dL, respectively for women and ≥13.0, 11.0-12.9, <11.0 g/dL for men).
“At the time of incident CKD, mean age was 72 years, 97% were male, and mean eGFR was 51 mL/min per 1.73 m2,” according to the researchers. “Over a median 4.1 years of follow-up, 92,306 (15%) veterans developed dementia before kidney failure or death.”
Results indicated that, compared to veterans with CKD without anemia, multivariable-adjusted models showed a 16% (95% confidence interval [CI] 14% to 17%) significantly higher risk of dementia for those with mild anemia and a 27% (95% CI 23% to 31%) higher risk with moderate/severe anemia.
“Combined risk of kidney failure or death was higher at 39% (95% CI 37% to 40%) and 115% (95% CI 112% to 119%) for mild and moderate/severe anemia, respectively, compared to no anemia,” the study team added.
Limitations of the study included residual confounding from the observational study design and that findings might not be generalizable to the broader United States, according to the researchers.
“Anemia was significantly associated with increased risk of dementia among veterans with incident CKD, underscoring the role of anemia as a predictor of dementia risk,” the study concluded.
- Koyama AK, Nee R, Yu W, Choudhury D, et. al. Role of Anemia in Dementia Risk Among Veterans With Incident CKD. Am J Kidney Dis. 2023 Jul 27:S0272-6386(23)00735-7. doi: 10.1053/j.ajkd.2023.04.013. Epub ahead of print. PMID: 37516301.