Dementia Risk Is Impacted by Hemoglobin Levels

Individuals with either low or high hemoglobin levels may be at an increased risk for dementia and Alzheimer disease (AD), according to a new study.

To reach this conclusion, the researchers measured the serum hemoglobin in 12,305 participants of the Rotterdam Study who did not have dementia (mean age, 64.6 years).

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Of these participants, 5267 had undergone brain magnetic resonance imaging (MRI). Among those participants, the researchers assessed hemoglobin in relation to vascular brain disease, structural connectivity, and global cerebral perfusion in order to assess the risk for dementia and AD in relation to hemoglobin and anemia.

During a mean follow-up of 12.1 years, 1520 of the participants had developed dementia, 1194 of whom had AD.

According to the researchers, both low and high levels of hemoglobin levels were associated with an increased risk for dementia. In fact, having anemia—which 6.1% of participants had—was associated with a 34% increased risk for dementia and a 41% increased risk for AD.

This association between hemoglobin levels and dementia risk may be attributable to differences in white matter integrity and cerebral perfusion, according to the study authors. 

“Among individuals without dementia with brain MRI, similar U-shaped associations were seen of hemoglobin with white matter hyperintensity volume and structural connectivity, but not with presence of cortical and lacunar infarcts,” the researchers concluded. “Cerebral microbleeds were more common with anemia. Hemoglobin levels inversely correlated to cerebral perfusion.”

—Colleen Murphy

Reference: 

Wolters FJ, Zonneveld HI, Licher S, et al; Heart Brain Connection Collaborative Research Group. Hemoglobin and anemia in relation to dementia risk and accompanying changes on brain MRI [published online July 31, 2019]. Neurology. doi:10.1212/WNL.0000000000008003.