Blood pressure and intellectual function in elderly subjects

Abstract

Objective: to assess the relationship between hypertension and cognitive function in elderly subjects.

Methods: 17 subjects with uncomplicated hypertension (nine male, eight female) and 27 control subjects with similar educational level and age (18 male, nine female) were studied. These individuals were recruited, according to strict selection criteria, from a random sample of 120 elderly subjects living in the community, who had a normal Mini Mental State score. An extensive neuropsychological test battery, sensitive to mild cognitive impairment, was administered in standard conditions to measure attention, concentration and judgement, psychomotor speed, memory and learning. Affective disorders were also evaluated. In all patients a computed tomography scan was performed.

Results: subjects with high blood pressure had lower mean levels of performance in attentional measures; tapping test (inhibition of incorrect answers), three words-three shapes test (attempts; incidental memory) and reaction time to multiple stimuli. They also scored worse in clusters 1 and 2 of the Hamilton rating scale for depression. Confluent white matter lesions were found in nine hypertensive subjects (52.9%) and five controls (18.5%; P = 0.0170). Lacunes were demonstrated in 11 hypertensive (64.7%) and four normotensive people (14.8%; P = 0.0007). In a multivariate analysis (logistic regression), three cognitive variables (tapping, Hamilton cluster 2 and Hamilton total score) remained significantly associated with hypertension, independently of the presence of cerebral lesions.

Conclusions: in elderly otherwise normal hypertensive subjects, an attentional impairment may occur, which appears to be functional and possibly reversible rather than structural and progressive.