Iron deficiency impairs cognition, and a recent study found that those with hemoglobin < 10.0 g/dl scored more than one standard deviation below those with milder anemia.
A hemoglobin level below 11 g/dl, considered moderate iron deficiency anemia (IDA), affects 1.5 percent of the U.S. population and is more common among minority groups. However, little is known about the cognitive and neurovascular profiles of adults with IDA, even though the condition is known to inflict long-term structural and functional damage in children.
This study performed brain MRIs and cognitive testing on 34 otherwise healthy women with IDA to investigate if oxygen transport and metabolism are intact and if IDA affects brain size and cognitive performance. This study was presented as a poster at the 65th American Society of Hematology Annual Meeting and Exposition.
Baseline Characteristics
Blood donors were selected from Children’s Hospital Los Angeles, the University of California Los Angeles, Cedars Sinai, and City of Hope with point-of-care hemoglobin values below 10.5 g/dl. IDA was confirmed by tests done in a lab that looked at reticulocyte count, iron indices, methylmalonic acid, hemoglobin electrophoresis, homocysteine, and high-sensitivity C-reactive protein.
Low Iron Profile Was Noted
Evaluation of blood samples showed a characteristic IDA phenotype, including low ferritin and transferrin saturation, high iron binding capacity, low mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC), and hypochromic microcytosis.
Impaired Cognitive Function and Cerebrovascular Physiology
Several aspects of neurocognitive function were affected in women with hemoglobin levels below 10.0 g/dl and Cohen’s D scores between 0.7 and 1.5. The decrease in oxygen content caused a slight increase in cerebral blood flow (CBF), which was considerably lower than what was anticipated from previous controls, leading to impaired oxygen delivery to the brain. The fraction of oxygen extracted from the blood was independent of hemoglobin concentration, leading to a drop in cerebral metabolic rate.
Brain Structures and Their Relation to Cognitive Indicators
Approximately two-thirds of the aberrant cognitive indicators were associated with a decreased gray matter volume in the right temporal lobe. Correlating with the remaining impaired cognitive indices, there was a decrease in white matter volume in the right cingulate gyrus, corpus callosum, and cerebellum.
Source
Suriany, S. (2023, December 10). The impact of iron deficiency anemia on cerebrovascular physiology, brain structure, and cognitive function in otherwise healthy women. https://ash.confex.com/ash/2023/webprogram/Paper181396.html
