The relationship between temporal changes in blood pressure and changes in cognitive function: atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Although previous epidemiological studies have reported that hypertension is a major risk factor for decline in brain perfusion and atrophy, which are known to be related to cognitive decline, the impact of temporal changes in blood pressure on age-related cognitive declines has not been assessed.

METHODS: The present study evaluates changes in blood pressure and cognitive decline over a 6-year period in the Atherosclerosis Risk in Communities (ARIC) Study. This report is based on 8,058 men and women aged 48-67 years examined in the second (1990-92), and fourth (1996-98) ARIC cohort visits. Changes between these visits were measured in hypertension status and three cognitive function tests: Delayed Word Recall (DWR), the Digit Symbol Subtest of the Wechsler Adult Intelligence Scale-Revised (DSS/WAIS-R), and the Word Fluency (WF). Adjusted mean differences in cognitive function were compared among five categories of hypertension status by using linear regression modeling.

RESULTS: In the present study, older subjects with uncontrolled hypertension had a significantly larger mean DSS/WAIS-R score decline than normotensive subjects. Although other cognitive declines did not achieve statistical significance, both cross-sectional and change analysis suggested that partially controlled or uncontrolled hypertension is associated with a less favorable cognitive profile, particularly when considering results of the DSS and the WF tests.

CONCLUSIONS: The present study results provide some support to the hypothesis that hypertension status changes over 6 years in individuals initially aged 48-67 years are related to cognitive changes.