Affiliations: [a] Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| [b] Department of Laboratory Medicine, Lund University, Lund, Sweden
| [c] Department of Psychology, Umeå University, Umeå, Sweden
| [d] Department of Clinical Sciences, Umeå University, Umeå, Sweden
Correspondence:
[*]
Correspondence to: Anna Oudin, Occupational and Environmental Medicine, Unit for Sustainable Health, Department of Public Health and Clinical Medicine, 901 87, Umeå University, Umeå, Sweden. Tel.: +46 90 785 08 73; E-mail: anna.oudin@umu.se.
Abstract: It is widely known that the apolipoprotein E (APOE) ɛ4 allele imposes a higher risk for Alzheimer’s disease (AD). Recent evidence suggests that exposure to air pollution is also a risk factor for AD, and results from a few studies indicate that the effect of air pollution on cognitive function and dementia is stronger in APOE ɛ4 carriers than in non-carriers. Air pollution and interaction with APOE ɛ4 on AD risk thus merits further attention. We studied dementia incidence over a 15-year period from the longitudinal Betula study in Northern Sweden. As a marker for long-term exposure to traffic-related air pollution, we used modelled annual mean nitrogen oxide levels at the residential address of the participants at start of follow-up. Nitrogen oxide correlate well with fine particulate air pollution levels in the study area. We had full data on air pollution, incidence of AD and vascular dementia (VaD), APOE ɛ4 carrier status, and relevant confounding factors for 1,567 participants. As expected, air pollution was rather clearly associated with dementia incidence. However, there was no evidence for a modifying effect by APOE ɛ4 on the association (p-value for interaction > 0.30 for both total dementia (AD+VaD) and AD). The results from this study do not imply that adverse effects of air pollution on dementia incidence is limited to, or stronger in, APOE ɛ4 carriers than in the total population.
Keywords: Air pollution, Alzheimer’s disease, apolipoprotein E, dementia
