Association of hypertension and its treatment with dementia and cognitive functioning.

AIM

Hypertension is known to induce many pathological changes in the body, including cardiac hypertrophy, atherosclerosis, micro-aneurisms and stroke. Besides these conspicuous pathologies, it also has subtle effects on the functioning of the brain. These cognitive changes have received little attention despite the fact that they make a large impact on the daily functioning of affected persons. The present study was conducted to assess the effect of hypertension and related factors on cognitive functions in an Indian population.

METHODS AND RESULTS

A cohort of young hypertensive subjects was recruited after obtaining informed consent. Subjects with confounding factors, such as substance use, neurological disorders, endocrinopathies, inflammatory conditions and psychiatric illnesses, were excluded. The average systolic and diastolic blood pressure of the subjects since the onset of illness and prescription of drugs were noted from the records. Compliance was assessed with the help of information given by the subjects and their close relatives. The mini-mental state examination and a battery of neuropsychological tests (digit span test, trail making test, Stroop test, visuospatial working memory matrix and word fluency test) were applied to all participants. Univariate regression analysis was used for the assessment of association and a one-way analysis of variance was performed on categorical variables. The mean age of the subjects was 52 years, and the average duration of hypertension 9 years. Twelve subjects had dementia which could be attributed to the subtle effects of hypertension only. Blood pressure (both systolic and diastolic) had a significant negative association with the cognitive tests. Cognitive impairment was also seen in subjects who reported poor drug compliance and those using beta blockers, while calcium channel blockers played a protective role.

CONCLUSIONS

Hypertension was associated with a significant decline in cognitive functioning in younger subjects. Good compliance with drugs and the use of calcium channel blockers had a protective effect on hypertension-induced cognitive decline.