The association between low diastolic blood pressure in middle age and cognitive function in old age. A population-based study.

Background: previous longitudinal studies have shown an inverse relation between blood pressure and cognitive function. Objective: to determine the association between mid-life blood pressure and performance in different areas of cognitive function in late life. Subjects and methods: we recruited 502 men, aged 69‐74 years, from a population-based cohort in Uppsala, Sweden. Blood pressure had been measured at age 50 and we examined performance in 13 psychometric tests about 20 years later. Results: after the 39 men with a previous stroke had been excluded, there was an inverse relation between diastolic blood pressure at age 50 and performance 20 years later in the digit span test, the trail-making tests and in verbal fluency. The relationships were significant, independently of age, education and previous occupational level. Men within the lowest category of diastolic blood pressure (# 70 mmHg, n = 59) showed the best results. Baseline blood pressure levels were not linked to performance in tasks on vocabulary, verbal learning and memory or figure copying. Conclusions: low blood pressure in mid-life indicates a low long-term cerebrovascular risk and is associated with higher late-life performance in cognitive tests that mainly assess subcortico-frontal cognitive functions.