THE CANADIAN STUDY OF HEALTH AND AGING - RISK-FACTORS FOR ALZHEIMERS-DISEASE IN CANADA

Objective: To study risk factors for Alzheimer's disease (AD) based on data from the Canadian Study of Health and Aging. Design: Population- based case-control study. Setting: Communities and institutions in 10 Canadian provinces. Participants: Two hundred fifty-eight cases clinic ally diagnosed with probable AD, with onset of symptoms within 3 years of diagnosis, and 535 controls, frequency matched on age group, study center, and residence in community or institution, clinically confirm ed to be cognitively normal. Main outcome measure: Odds ratios (ORs) w ere calculated using unconditional logistic regression for previously hypothesized and potential risk factors for AD. Results: The OR for fa mily history of dementia was significantly elevated (2.62; 95% confide nce interval [CI], 1.53 to 4.51) and increased with the number of rela tives with dementia. Those with less education were at higher risk of AD, with an OR of 4.00 (95% CI, 2.49 to 6.43) for those with 0 to 6 ye ars, in comparison with those with 10 or more years. Head injury achie ved borderline significance. A history of arthritis resulted in a low risk of AD (OR = 0.54; 95% CI, 0.36 to 0.81), as did a history of use of nonsteroidal anti-inflammatory drugs, Initial analyses showed an in creased risk of AD for occupational exposure to glues as well as to pe sticides and fertilizers; the increased risk was greater in those with less education. Conclusion: This study confirmed a number of previous ly reported risk factors for AD, but provided little support for other s. A new finding was an increased risk for those with occupational exp osure to glues as well as pesticides and fertilizers, but this needs f urther study.