Iron status is related to cognitive performance in the elderly InCHIANTI population

Background: Research supports a relation between iron status and cognitive development in children and between anemia status and cognition in the elderly. Limited data exists on iron's role in elderly cognition, particularly using biochemical measures. InCHIANTI, a longitudinal study in elderly Italians, investigates mobility. Here, we present baseline data analyses from InCHIANTI on the relation of iron status to cognition (n=1,055). Methods: Iron status was characterized by complete blood count measures, transferrin receptor (TfR), and ferritin (Ft) and cognition by the Mini-Mental State Examination (MMSE) and Trail Making Tests (TMT) A and B. Results: Mean MMSE and TMT scores differed between iron deficient anemic (IDA) and iron sufficient (IS) individuals (p=0.0001 and p<0.01, respectively) and between iron deficient (ID) and IS individuals (MMSE, p<0.05; TMT A, p<0.01; TMT B, p<0.001). In females with less than an elementary education, an equality-of-medians test showed MMSE scores differed between IDA and IS (raw MMSE, p<0.05; adjusted MMSE, p<0.1), and in females with an elementary education, TMT A scores differed between IDA and IS (p<0.05); differences disappeared after excluding dementia (MMSE<19). Among elementary educated males with TMT B scores (a group with no dementia), ID had worse TMT B scores than IS (p<0.05). Multiple linear regression controlling for sex, site, age, and education revealed a >15 point higher TMT A score in ID compared to IS (p<0.1). Conclusions: Results suggest relations between better iron status and improved cognition. Ongoing longitudinal analyses will be valuable in clarifying these relations in community-dwelling elderly.