Reducing the risk of dementia: efficacy of long-term treatment of hypertension. Stroke. 2006 May; 37(5):1165-1170.
The authors evaluated the risk of dementia and cognitive decline associated with duration of antihypertensive treatment. Data came from the Honolulu Asia Aging Study on Japanese-American men followed since 1965. The subjects included in this analysis were hypertensive from midlife and dementia-free in 1991 (mean age 76.7 years). In 1991, 1994, and 1997, global cognitive function was assessed with the Cognitive Abilities Screening Instrument (CASI) and dementia by a standardized examination using international criteria. The sample was grouped by treatment duration (never-treated hypertensives (NTH), < 5 years, 5 to 12 years, > 12 years). Normotensive subjects up to 1991 were included in the analysis as a control group. For each additional year of treatment there was a reduction in the risk of incident dementia (hazard ratio [HR] = 0.94, 95% CI, 0.89 to 0.99). The risk for dementia in subjects with > 12 years of treatment was lower compared to NTH (HR for dementia = 0.40; 95% CI, 0.22 to 0.75 and for Alzheimer's disease HR = 0.35; 95% CI, 0.16 to 0.78) and was similar to the normotensives. Nondemented subjects with 5 to 12 years of treatment had lower yearly CASI decline compared to NTH. Results suggest that in hypertensive men, the duration of the antihypertensive treatment is associated with a reduced risk for dementia and cognitive decline.