Anemia Associated With Increased Dementia Risk in CKD

Results of studies have suggested that anemia is a risk factor for dementia. Other study results have indicated that older adults with chronic kidney disease (CKD) are at increased risk for both anemia and dementia. However, according to Alain Koyama, ScD, and colleagues it is unclear how CVD influences the association between anemia and dementia.

The researchers performed an analysis designed to examine the association between anemia and the risk of dementia in a cohort of US veterans with new-onset CKD. Results were reported during a poster session at the American Society of Nephrology Kidney Week 2022 in a poster titled Anemia and Dementia Risk in US Veterans With New-Onset CKD.

The cohort included 444,474 veterans ≥65 years of age with new-onset CKD, defined as estimated glomerular filtration rate <60 mL/min/1.73 m² for >3 months, who were treated in the 2005-2014 Veterans Health Administration (VHA). Participants were followed for 2 to 14 years. Eligible veterans were free of dementia and end-stage kidney disease at baseline.

Anemia severity was identified using baseline hemoglobin with predefined thresholds (g/dL): moderate or severe, <11.0; mild, 11.0-11.9; and none, ≥12.0 for women; and <11.0, 11.0-12.9, and ≥13.0 for men, respectively. The outcome of interest was incident dementia over follow-up, identified using International Classification of Diseases codes in claims from the VHA and the Centers for Medicare & Medicaid Services. To account for the competing risk of death, the researchers estimated unadjusted and adjusted risks of dementia using cause-specific hazard ratios (HRs).

Mean age of the cohort was 76.3 years and 98% were men. At baseline, 5% (n=22,3239) had moderate or severe anemia, 26% (n=114,314) had mild anemia, and 69% (n=307,831) had no anemia. For patients with moderate or severe anemia, the incidence of dementia per 1000 person-years was 52.7 cases (adjusted HR, 1.23; 95% CI, 1.19-1.27); for those with mild anemia, the incidence per 1000 person-years was 46.1 cases (adjusted HR, 1.12; 95% CI, 1.10-1.14). For those with no anemia, the incidence was 35.9 cases.

Following multivariable adjustment, compared with patients without anemia, those with moderate or severe anemia has a 23% significant increased risk of dementia Those with mild anemia had a 12% significant increased risk.

“Among patients with incident CKD, anemia was independently associated with an increased risk of dementia,” the authors said.

Source: Koyama A, Yu W, Burrows NR, et al. Anemia and dementia risk in US veterans with new-onset CKD. TH-PO659. Abstract of a poster presented at the American Society of Nephrology Kidney Week 2022; November 3, 2022; Orlando, Florida.