title: Shear stress in the common carotid artery is related to both intima-media thickness and echogenecity. The Prospective Investigation of the Vasculature in Uppsala Seniors study.
abstract: It has previously been shown that the degree of shear stress (SS) in the carotid artery is related to both plaque occurrence and intima-media thickness (IMT). Since the echogenecity also is an important feature of plaques, we investigated if a reduced shear stress also is related to the echolucency of plaque and the intima-media complex. In the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study, a population-based study of 1016 subjects aged 70, left common carotid artery diameter, IMT, the grey scale median (GSM) of the intima-media complex (IM-GSM) and the blood flow velocity were measured by ultrasound. Occurrence of plaque was noted, and the echogenecity of the plaques was visually estimated by the Gray-Weale classification. Shear stress was inversely related to both IMT and IM-GSM (p=0.0084 and p=0.003, respectively), independently of gender and coronary risk, estimated by the Framingham risk score. Shear stress was lower in subjects with carotid plaque (44% of the sample) than in those without (p=0.0013), and was inversely related to the echogenecity in the subjects with plaque (p=0.0092), independently of gender and coronary risk. A low shear stress in the common carotid artery was associated with both a thick IMT and an echolucent intima-media complex. A similar picture was seen when overt plaques were evaluated, suggesting that shear stress is of importance for both the extent and composition of atherosclerosis.
authors.affiliation: Department of Medicine, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Lind
authors.forename: Jessika
authors.initials: J
authors.lastname: Andersson
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
authors.forename: Bo
authors.initials: B
authors.lastname: Sandhagen
mesh_terms: D000368:Aged; D000375:Aging / Q000097:blood / Q000502:physiology*; D050197:Atherosclerosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D001809:Blood Viscosity; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000473:pathology / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D013314:Stress, Mechanical; D017539:Tunica Intima / Q000000981:diagnostic imaging* / Q000473:pathology / Q000502:physiology; D017540:Tunica Media / Q000000981:diagnostic imaging* / Q000473:pathology / Q000502:physiology; D014463:Ultrasonography