Background and aims: Blood pressure (BP) is a key modifiable risk factor for atherosclerosis. How BP across different life stages associates with carotid plaque in mid-adulthood remains unclear, which is the aim of this study.

Methods: The sample included 1889 participants from the Cardiovascular Risk in Young Finns Study who had their BP measured in childhood (6-18 years), young adulthood (21-39 years), and mid-adulthood (40-56 years). Outcomes were the carotid plaque presence and area in mid-adulthood. A Bayesian relevant life-course exposure model was used to estimate the life-course association of BP with carotid plaque and determine the relative contributions attributed to each life stage.

Results: After a 38-year follow-up, 745 participants (39.4%) developed carotid plaques. Cumulative systolic BP (SBP) from childhood, young-, and mid-adulthood was associated with carotid plaque presence in mid-adulthood [for each 1-SD increase (∼12 mm Hg), relative risk (95% credible intervals (CrIs)): 1.22 (1.10-1.36)], with SBP at each life stage contributing approximately equally (relative weights: childhood, 39.4%; young adulthood, 37.9%; mid-adulthood, 22.7%). Cumulative SBP was associated with carotid plaque areas [β (95% CrIs), 0.16 (0.08-0.23)] square millimetre, with mid-adulthood SBP showing a higher contribution (relative weights: childhood, 12.5%; young adulthood, 25.0%; mid-adulthood, 62.5%). Similar patterns were observed for diastolic BP, pulse pressure, and mean arterial pressure.

Conclusions: Blood pressure at each life stage contributes equally to carotid plaque presence, with mid-adulthood BP associated with a greater contribution to plaque area. These findings underscore the importance of maintaining normal BP throughout life to reduce atherosclerosis risk and suggest that intensive BP management in mid-adulthood may help slow plaque progression.

Keywords: Atherosclerosis; Blood pressure; Carotid artery plaques; Life-course perspective; Paediatrics.

© The Author(s) 2025. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.