Air pollution linked to sex-specific biomarker changes in adults at Alzheimer's risk

Researchers examined long-term residential exposure to traffic-related air pollution in 226 cognitively unimpaired, middle-aged adults at increased risk of Alzheimer's disease from the ALFA+ longitudinal cohort. Participants underwent cerebrospinal fluid assessment at baseline and three years for biomarkers of Alzheimer's pathology, neurodegeneration, astrocytic and microglial activity, and inflammation. Exposure to nitrogen dioxide, PM10, PM2.5, and PM2.5 absorbance was estimated using land-use regression models.

Higher pollution exposure was associated with longitudinal increases in glial fibrillary acidic protein (GFAP) and interleukin-6, primarily in women. Analyses identified sex-dependent associations with astrocytic and inflammatory biomarkers. GFAP partially mediated associations between pollution exposure and worsening executive and attentional performance. The abstract did not report effect sizes or confidence intervals.

The findings suggest sex-specific susceptibility to pollution-associated astroglial and neuroinflammatory changes before cognitive impairment. However, this observational study does not establish causality, and statistical mediation does not prove a biological mechanism. The selected at-risk population may limit generalizability. Only the abstract was available, preventing assessment of detailed adjustment methods and other limitations.