Abstract
OBJECTIVES: To test the hypothesis that hypertension, high blood pressure, and high pulse pressure (PP) are independently associated with lower cognitive function. DESIGN: Cross-sectional study of persons examined in 1988 to 1994. SETTING: U.S. noninstitutionalized population. PARTICIPANTS: Six thousand one hundred sixty-three men and women aged 60 and older who participated in the Third National Health and Nutrition Examination Survey (NHANES III). MEASUREMENTS: Measurements included blood pressure, short-portable Mini-Mental State Examination (sp-MMSE), self-reported history of hypertension, diagnosis, and treatment. RESULTS: In the initial bivariate analysis within age groups of 60 to 64, 65 to 69, and 70 to 74, optimal blood pressure (< 120/80 mmHg) was associated with best cognitive performance; the severe hypertension group had the poorest performance in all age groups except the very old (> or = 80), where the pattern was reversed, showing poorest performance in the optimal blood pressure group and best in the group with moderate hypertension. This pattern changed slightly in multiple regression analyses modeling sp-MMSE as the outcome variable. Higher stage of hypertension according to the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure and higher PP were associated with worse cognitive performance than normal blood pressure at ages 70 to 79 and 80 and older. No significant negative association was seen in subjects aged 60 to 69. Subjects with treated but uncontrolled hypertension had significantly lower sp-MMSE scores than those without hypertension or with controlled hypertension after controlling for age, sex, ethnicity, income, and PP. CONCLUSION: At age 70 and older, high blood pressure, hypertension, and uncontrolled blood pressure are associated with poorer cognitive function than normal blood pressure. Optimal control of blood pressure may be useful in preserving neurocognitive loss as the population ages.