Prevalence of Silent Atherosclerosis across Adult Life.

BACKGROUND: Atherosclerosis may begin in early adulthood and remain clinically silent for decades before cardiovascular disease manifests. Although silent atherosclerosis is associated with cardiovascular events and death independent of traditional cardiovascular disease risk factors, its age- and sex-specific prevalence, vascular territory distribution, and plaque volume across adult life remain incompletely defined. METHODS: We conducted a prospective cohort study in Denmark and Spain. Adults 18 to 70 years of age without known atherosclerotic cardiovascular disease were enrolled in five prespecified age strata that included balanced numbers of women and men. Silent atherosclerosis was assessed at baseline with three-dimensional vascular ultrasonography of the carotid and femoral arteries and with coronary computed tomographic angiography. RESULTS: A total of 16,808 adults were enrolled in the study. The mean (±SD) age of the participants was 45±12 years, and 51.4% were women. Silent atherosclerosis was present in 57.1% of the participants (95% confidence interval, 56.3 to 58.0). In the youngest age stratum (18 to 29 years), atherosclerosis was present in 8.7% of the men and 6.7% of the women; prevalence increased with age, with a later, steeper midlife rise among women. Among participants in the younger age strata, atherosclerosis was most often peripheral and confined to a single vascular territory; with increasing age, plaque volume increased exponentially and the prevalence of multiarterial involvement became more frequent. Isolated coronary-artery atherosclerosis was uncommon in every age stratum (≤9.3% of men and ≤5.0% of women). CONCLUSIONS: This study of silent atherosclerosis showed that the disease was detectable in early adulthood, with age- and sex-associated increases in prevalence across arterial territories and marked increases in plaque volume. (Funded by the Novo Nordisk Foundation; REACT ClinicalTrials.gov number, NCT06692127.).