Reducing the risk of dementia efficacy of long-term treatment of hypertension

Background and Purpose-The efficacy of treating older persons for hypertension remains controversial. Although clinical trials suggest no short-term harm, or some benefits, there are little data on the effect on cognitive function of long-term antihypertensive treatment. We evaluated the risk of dementia and cognitive decline associated with duration of antihypertensive treatment. Methods-Data are 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 (ASI) and dementia by a standardized examination using international criteria. The sample was grouped by treatment duration (never-treated hypertensives (TH), <= 5 years, 5 to 12 years, > 12 years). Normote nsive subjects up to 1991 were included in the analysis as a control group. Results-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 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. Conclusions-Results suggest that in hypertensive men, the duration of the antihypertensive treatment is associated with a reduced risk for dementia and cognitive decline.