Carotid Plaque and Intima-Media Thickness Assessed by B-Mode Ultrasonography in Subjects Ranging From Young Adults to Centenarians

Abstract

Background and Purpose —To investigate relationships among plaque formation, increasing intima-media thickness, and age, we examined ultrasonographically carotid arteries of subjects who had no major atherosclerotic risk factors and who ranged in age from young adults to centenarians. Methods —We studied 319 healthy subjects (154 men, 165 women; age range, 21 to 105 years) with no history of hypertension, diabetes mellitus, or atherosclerotic disease. Mean intima-media wall thickness (IMT) of common carotid arteries at plaque-free sites and prevalence of plaques were evaluated by B-mode ultrasound. Results —Mean common carotid IMT increased in a linear manner with age for all decades of life, including centenarians [IMT=(0.009×Age)+0.116] ( r =0.83). In centenarians (n=30), intima-media complexes were diffusely thickened (mean IMT, 1.01 mm). Plaque prevalence increased up to the tenth decade of life (83.3%, n=30) but decreased in centenarians (60.0%). IMT and plaque prevalence were closely associated in the seventh and eighth decades of life but not at older ages. Conclusions —The present study indicates that increased IMT is a physiological effect of aging that corresponds to diffuse intimal thickening, especially in very elderly persons, and that IMT is distinct from pathological plaque formation.