Abstract 3027: Report of Stroke Symptoms in the Absence of Stroke Predicts Incident Cognitive Impairment
Introduction: Stroke and vascular risk factors are recognized as important markers of increased risk of cognitive impairment. Experience of stroke-like symptoms and/or transient ischemic attack (SS/TIA) are suspected to represent another independent marker of risk for cognitive impairment.
Methods: We assessed these relationships in REGARDS, a national longitudinal cohort study following over 30,000 black and white participants aged 45 and older from the 48 contiguous states. Cognitive function is assessed by several scales, including the Six-Item Screener (SIS), conducted by telephone at baseline and annually during follow-up. After excluding those who were impaired at first assessment, 23,830 participants (mean baseline age 64.2) were stroke free at baseline and had at least two cognitive function assessments (11,096 with two to four, and 12,734 with more than four). Observation time was censored after a suspected stroke during follow-up (censoring 1439 assessments in 515 participants). SS/TIA were assessed using the Questionnaire for Verifying Stroke-Free Status. The association between report of SS/TIA and subsequent impairment was assessed using logistic regression, both univariately and after adjustment for a variety of risk factors. In addition, the role of the Framingham Stroke Risk (FSR) in these relationships was examined. Incident impairment was characterized as a score of 4 or fewer on the most recently assessed SIS. Models were fitted separately for white and black subjects to evaluate race-specific effects.
Results: Among blacks, the presence of any incident SS/TIA was associated with 1.66 (95% CI: 1.45, 1.89) times the likelihood of impairment in an unadjusted model, compared to those with no SS/TIA, which was slightly attenuated to 1.41 (95% CI: 1.23, 1.62) in a model incorporating gender, income, region and education. Among whites, the unadjusted OR was 2.08 (95% CI: 1.81, 2.39), with an adjusted OR of 1.85 (95% CI: 1.61, 2.13). The association between SS/TIA differed by FSRF, with a stronger association between SS/TIA and impairment among those with lower FSR, both for blacks and whites.
Discussion: In an initially stroke-free cohort and with censoring of incident stroke cases in the follow-up, report of SS/TIA was strongly related to increased risk of cognitive impairment. The stronger association between self-report of SS/TIA and incident cognitive impairment among those with lower FSR score suggests these symptoms may reflect risk factors for cognitive impairment not captured in the FSR. This effect was larger in whites, suggesting differential sensitivity or exposure to this risk.
- © 2012 by American Heart Association, Inc.