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O2–01–02: Antioxidant vitamin intake and dementia in the oldest‐old: The 90+ study
Author(s) -
Corrada Maria M.,
Kawas Claudia H.,
Paganini-Hill Annlia
Publication year - 2007
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2007.04.045
Subject(s) - dementia , medicine , cohort , logistic regression , gerontology , cohort study , prospective cohort study , odds ratio , telephone interview , population , pediatrics , environmental health , disease , social science , sociology
1,836 dementia-free individuals, who represented the Japanese American population aged 65 and over in King County, WA. Part of this baselineevaluation included the administration of the 3RT, a computer-assisted test of reaction time (n 1,646), the NART, and questions about age, gender, education. DSM-IV criteria were used to diagnose dementia over the following 10 years. We used Cox Proportional Hazards regression with follow-up as the time axis in models including age at entry, gender and education. Results: 173 subjects were diagnosed with incident dementia; 147 had CRT data. The HR for dementia associated with education (1-year increase) was 0.96 (95% CI 0.91-0.99, p 0.029). When CRT median (of 32 trials) was added to the model, each 10 milliseconds (ms) increase in time was associated with a 0.7% increase in risk for dementia (95% CI 1.002-1.012, p 0.007) and the association with education was lost (p .127). Among a subset of 694 subjects with NART data, an increase in 10ms in the CRT measure increased the risk for dementia by 3.6% (95% CI 1.009-1.064, p 0.009). In models including both CRT and NART, both were independently significant [HR associated with CRT 1.034 per 10 ms (95% CI 1.007-1.062, p 0.014); HR associated with estimated IQ score 0.95 per point (95% CI 0.91-0.99, p 0.0199)] with education losing significance in all models that included either CRT or NART. Conclusions: The relation between education and dementia is confounded by reaction time and estimated IQ score. Choice reaction time and NART measure different phenomena that contribute independently to the risk of dementia over a 10-year follow-up period.