Analysis Finds Anemia, Hemoglobin Associated With Cognitive Impairment

Low hemoglobin and anemia were associated with low cognitive function in older patients, according to analysis of the Longitudinal Ageing Study in India – Harmonized Diagnostic Assessment of Dementia (LASI-DAD) data set.

“We have established for the first time in a large South Asian population that anemia may be an important potentially modifiable risk factor for low cognitive function in an elderly population,” wrote authors, led by Laura Winchester, MD, from Oxford University in England.

Fortunately, testing for these conditions is generally widely accessible, the authors noted.

“Detection of anemia and low hemoglobin concentration is possible using common blood count assays making clinical assessment for the condition accessible and broadening research possibilities and impact particularly for dementia prevention,” Dr. Winchester added.

Anemia Associated with Cognitive Impairment

The analysis included 2,758 patients aged 60 or older from the LASI-DAD data set with available data on complete blood count from venous blood plus scores from episodic memory, executive function, and verbal fluency tests. The authors used linear regression to test for associations between anemia and hemoglobin concentration and 11 cognitive domains. Associations identified in the study were then validated against the US Health and Retirement Study (HRS) cohort of 5,720 patients.

The study found an association between anemia and poor memory (P=.0054), as well as a positive association between hemoglobin concentration and 10 cognitive domains (β=0.041-0.071; P<.05). The strongest associations were between hemoglobin and immediate episodic, delayed episodic, and broad domain memory tests (β=0.061-0.071; P<.005).

Additionally, general cognitive scores were associated with other red blood cell count tests including red blood cell distribution width (β=-0.11, P<.0001) and mean corpuscular hemoglobin concentration (β=0.06, P=.0001). The researchers stated positive associations from the LASI-DAD analysis were validated in the HRS cohort (P<.05).

“Increased prevalence anemia in South Asian cohorts makes further work into the effects and causes an important next step,” they suggested.

Reference

Winchester LM, Newby D, Ghose U, et al. Anemia, hemoglobin concentration and cognitive function in the Longitudinal Ageing Study in India-Harmonized Diagnostic Assessment of Dementia (LASI-DAD) and the Health and Retirement Study. Preprint. medRxiv. 2024;2024.01.22.24301583. doi:10.1101/2024.01.22.24301583