Past Infections Are Tied to Cognitive Impairment

To examine a possible association between infection and cognitive impairment, researchers analyzed blood samples from more than 1600 multiethnic adults without prior stroke and created a composite measure of exposure to Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpes simplex 1 and 2.

The composite was significantly associated with cognitive impairment on baseline Mini-Mental State Examination testing and subsequent telephone assessments of cognition, but not with progressive cognitive decline over the period of investigation. When the results were adjusted for demographic variables known to affect cognitive decline and vascular risk factors, the strength of the association was attenuated.