Abstract 3837: Vascular Risk Profiles and Cognitive Impairment in a 20-year Follow-up of Three Ethnic Groups: the Southall and Brent REvisited (SABRE) Cohort
Introduction: There is substantial ethnic variation in vascular risk profiles and their outcomes. For example, stroke risk is raised by 50-100% in Black and South Asian compared to White UK residents but is more strongly associated with diabetes than hypertension in the former two groups. Associations with cognitive outcomes have not been previously compared.
Hypothesis: Mid-life hypertension and diabetes will be more strongly associated with later life cognitive impairment in Black and South Asian compared to White residents.
Methods: SABRE is a UK community based tri-ethnic (White, Black and South Asian) cohort of male and female London residents aged 40-69 years at baseline (1988-1990), and 58-86 years at follow up (2008-2011). Hypertension at baseline (resting blood pressure >140/90 or antihypertensive treatment) and diabetes at either exam were investigated in relation to cognitive impairment at follow-up. Cognitive impairment was ascertained as the lowest 10% of averaged z-scores calculated separately within the 3 ethnic groups for 9 tests: immediate and delayed word list recall, digit span forwards and backwards, verbal fluency, Color Trailmaking Tests A and B, delayed visual recall and the Community Screening Instrument for Dementia. Age, gender and years of education were entered as covariates.
Results: Prospective data were analysed on 570 White, 432 South Asian and 185 Black residents. Baseline hypertension prevalences in these three groups were 14.8%, 27.1% and 37.2% respectively and diabetes prevalences were 19.5%, 43.4% and 41.3% respectively. Hypertension (p=0.005) and diabetes (p=0.029) were associated with follow-up cognitive impairment after full adjustment. On stratifying by ethnic group, no significant associations were found in White participants, hypertension was only associated with cognitive impairment in South Asians and diabetes only in Black participants. Hypertension and diabetes in combination were associated with cognitive impairment to a similar extent in both South Asian and Black participants, but not in Europeans.
Conclusion: Vascular risk factors vary in their impact on cognitive impairment between ethnic groups which may reflect underlying differences in risk profiles and modification of their impact on end-organ damage. Multi-ethnic cohorts present a valuable opportunity for investigating more heterogeneous risk profiles and better clarifying mechanisms underlying the impact of individual risk factors.
- © 2012 by American Heart Association, Inc.