Common infections and neuroimaging markers of dementia in three UK cohort studies

Abstract

Introduction:We aimed to investigate associations between common infections and neuroimaging markers of dementia risk (brain volume, hippocampal volume, white matter lesions) across three population-based studies.Methods:We tested associations between serology measures (pathogen serostatus, cumulative burden, continuous antibody responses) and outcomes using linear regression, including adjustments for total intracranial volume and scanner/clinic information (basic model), age, sex, ethnicity, education, socioeconomic position, alcohol, BMI, and smoking (fully adjusted model). Interactions between serology measures andAPOEgenotype were tested. Findings were meta-analysed across cohorts (Nmain=2632; NAPOE-interaction=1810).Results:Seropositivity to JC virus associated with smaller brain volumes in basic models (β=-3.89ml[-5.81,-1.97],padjusted<0.05); these were largely attenuated in fully adjusted models (β=-1.59ml[-3.55,0.36],p=0.11). No other relationships were robust to multiple testing correction and sensitivity analyses, but several suggestive associations were observed.Discussion:We did not find clear evidence for relationships between common infections and markers of dementia risk. Some suggestive findings warrant testing for replication.