Exposure to common infectious agents is associated with domain-specific cognitive impairment among community-dwelling older adults, according to study findings published in Alzheimer’s & Dementia.
Evidence regarding the effects of individual pathogens on specific cognitive domains is limited. Researchers from Columbia University and the University of Miami analyzed data from the Northern Manhattan Study to examine whether serologic evidence of infection with 5 common pathogens (herpes simplex virus [HSV]-1, HSV-2, cytomegalovirus [CMV], Helicobacter pylori, and Chlamydia pneumoniae)was associated with cognitive performance and risk for mild cognitive impairment (MCI) or dementia.
The study included 593 participants (mean [SD] age, 71 [8] years; 39% men; 69% Hispanic) who were free of stroke and dementia at baseline. Participants underwent serologic testing for infectious exposures and completed neuropsychological assessments clustered into 4 cognitive domains: memory, language, processing speed, and executive function. Over a mean follow-up of 7.8 years, 30% of participants developed cognitive impairment, and 17% were diagnosed with dementia.
…[C]ommon infectious exposures may contribute to cognitive aging and dementia in late life.
After adjusting for demographic, vascular, and psychosocial confounders, CMV and HSV-2 seropositivity were significantly associated with poorer executive function (β = -0.29; 95% CI, -0.51 to -0.08; P = .007 and β = -0.19; 95% CI, -0.36 to -0.02; P = .03, respectively), while C pneumoniae seropositivity was linked to reduced language performance (β= -0.17; 95% CI, -0.32 to -0.01; P =.03).
In unadjusted models, CMV seropositivity was associated with increased risk for incident MCI (hazard ratio [HR], 1.22; 95% CI, 1.09-1.36; P =.0005) and dementia (HR, 1.18; 95% CI, 1.02-1.37; P = .024). However, these associations were no longer significant after adjustment.
Study limitations include reliance on serologic titers, which indicate exposure rather than active infection or reactivation, possible misclassification of infection status over time, and limited power due to few dementia cases.
“Taken together, we provide evidence that CMV exposure is associated with decreased executive function and possibly increases risk for cognitive impairment and dementia, adding to a growing body of evidence that common infectious exposures may contribute to cognitive aging and dementia in late life,” the researchers concluded.
Disclosures: This research was supported by the National Institutes of Health. Please see the original reference for a full list of disclosures.
This article originally appeared on Neurology Advisor
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