Abstract
Lower hemoglobin levels have been associated with cognitive decline in older persons. The objective of this study was to investigate the relationship between lower hemoglobin levels and common, age-related neuropathologies associated with cognitive decline. Hemoglobin and neuropathology measures were available in 113 deceased, community-dwelling, older adults participating in the Rush Memory and Aging Project, a prospective, observational, clinical pathology study of aging. The mean hemoglobin level was 13.0 g/dL (SD = 1.4) and was measured 3.2 (SD = 1.3) years prior to death. Thirty-five participants had at least one chronic macroscopic infarction and twenty-nine had at least one chronic microscopic infarction. Eleven participants had Lewy Bodies. The mean Alzheimer's disease pathology score based on a summary measure of neuritic plaques, diffuse plaques, and neurofibrillary tangles was 0.56 unit (SD = 0.56; range = 0, 2.34). Using logistic regression models adjusted for age at death, gender, and education, each g/dL lower hemoglobin level increased the odds for having a chronic macroscopic infarction by 37% (95% CI = 1.01, 1.86) but not for having a chronic microscopic infarction (OR = 1.11; 95% CI = 0.82, 1.52) or Lewy Bodies (OR = 1.07; 95% CI = 0.68, 1.68). In an adjusted multiple regression model, hemoglobin level was not associated with the global AD pathology measure (parameter estimate = −0.02, SE = 0.03, p = 0.6). In secondary analyses, lower hemoglobin levels were associated with higher odds of having a chronic macroscopic infarction in a subcortical region but not with higher total subcortical chronic macroscopic infarction volume. In conclusion, lower hemoglobin levels appear to be associated with chronic macroscopic infarctions but not other common age-related neuropathologies.