Systolic blood pressure at age 40 and cognitive function 25 years later: the Akershus Cardiac Examination (ACE) 1950 Study

Abstract

Objectives: Hypertension in midlife is a risk factor for cognitive impairment. Still, the ideal midlife blood pressure (BP) remains unknown. We examined associations between different systolic blood pressure (SBP) levels at the age of 40-43 years and change in SBP over a 25-year period with cognitive function at age 62-65 years.

Methods: We included 2424 individuals born in 1950 who had participated both in the Age 40 Program (1990-1993) and the Akershus Cardiac Examination (ACE) 1950 Study (2012-2015). The exposure was SBP at age 40-43 years and the outcome was cognitive function at age 62-65 years, assessed with Montreal Cognitive Assessment, Delayed recall trial from the Consortium to Establish a Registry for Alzheimer's Disease Word List Memory Task, and Trail Making Test part B (TMT B).

Results: Participants were 40.1 ± 0.3 years old with mean SPB 128 ± 13 mmHg at the Age 40 Program, and 63.9 ± 0.6 years old with mean SPB 138 ± 18 at the ACE 1950 Study. Adjusted linear regressions showed no associations between SBP and subsequent cognitive function. In logistic regressions, individuals with SBP ≥140 mmHg, compared to individuals with SBP <120 mmHg (odds ratio 2.29, 95% confidence interval 1.28-4.10, P-value 0.005) had increased risk of an abnormal TMT B-score. Change in SBP during the 25-year follow-up was not associated with cognitive function.

Conclusions: SBP ≥140 mmHg at age 40-43 was associated with reduced capacity on TMT B, a domain specific cognitive test sensitive to vascular impairment. No other associations were found between SBP, or change in SBP, and cognitive function.

Trial registration: ClinicalTrials.gov NCT01555411.