Potentially Modifiable Dementia Risk Factors in Canada: An Analysis of Canadian Longitudinal Study on Aging with a Multi-Country Comparison

Abstract

AbstractBACKGROUNDPrevious estimates suggested that up to 40% of dementia cases worldwide are associated with modifiable risk factors, however, these estimates are not known in Canada. Furthermore, sleep disturbance, an emerging factor, has not been incorporated into the life-course model of dementia prevention.ObjectiveTo estimate the population impact of 12 modifiable risk factors in Canadian adults including sleep disturbance, by sex and age groups, and to compare with other countries.DesignCross-sectional analysis of Canadian Longitudinal Study on Aging Baseline dataSettingCommunityParticipants30,097 adults aged 45 years and older.MeasurementsPrevalence and Population Attributable Fraction (PAF) of less education, hearing loss, traumatic brain injury, hypertension, excessive alcohol, obesity, smoking, depression, social isolation, physical inactivity, diabetes, and sleep disturbance.ResultsThe risk factors with the largest PAF were later life physical inactivity (10.2%; 95% CI, 6.8% to 13%), midlife hearing loss (6.5%; 3.7% to 9.3%), midlife obesity (6.4; 4.1% to 7.7%), and midlife hypertension (6.2%; 2.7% to 9.3%). The PAF of later life sleep disturbance was 3.0% (95% CI, 1.8% to 3.8%). The 12 risk factors accounted for 51.9% (32.2% to 68.0%) of dementia among men and 52.4% (32.5% to 68.7%) among women. Overall, the combined PAF of all risk factors was 49.2% (31.1% to 64.9%), and it increased with age.ConclusionNearly up to 50% of dementia cases in Canada could be prevented by modifying the 12 risk factors across the lifespan. Canadian risk reduction strategies should prioritize targeting physical inactivity, hearing loss, obesity, and hypertension.