Association between intima-media thickness and wall shear stress in common carotid arteries in healthy male subjects.
BACKGROUND
Atherosclerotic lesions lie in regions of low wall shear stress. No relationship between wall shear stress and intima-media thickness in vivo has been reported. Aims of the present study were to verify the reproducibility of wall shear stress measurement in vivo and to evaluate its association with intima-media thickness in the common carotid artery in healthy subjects.


RESULTS
Wall shear stress was calculated according to the following formula: Shear Stress = Blood Viscosity x Blood Velocity/Internal Diameter. Blood viscosity was measured by use of a cone/plate viscometer. Blood velocity, internal diameter, and intima-media thickness were measured by high-resolution echo Doppler. Twenty-one healthy male subjects were investigated. Peak and mean shear stress values were 29.5 +/- 8.2 and 12.1 +/- 3.1 dynes/cm-2 (mean +/- SD), respectively. Peak shear stress was inversely related to intima-media thickness (r = .62), age (r = .77), systolic blood pressure (r = .61), and body mass index (r = .59) (P < .001 for all coefficients). Mean shear stress yielded similar results. The relationship between shear stress and intima-media thickness was independent of age, blood pressure, and body mass index. The reproducibility, calculated by Kendall's W test, was statistically significant.


CONCLUSIONS
Our results demonstrate that common carotid artery wall shear stress measurement in vivo is reproducible. It inversely relates to intima-media thickness, age, systolic blood pressure, and body mass index. These findings confirm in vivo the role of shear stress in intima-media thickening.
Gnasso
A
A
University of Reggio Calabria, Dipartimento di Medicina, Sperimentale e Clinica, Centro Aterosclerosi, Catanzaro, Italy.
Carallo
C
C
Irace
C
C
Spagnuolo
V
V
De Novara
G
G
Mattioli
P L
PL
Pujia
A
A
D000328:Adult; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D001809:Blood Viscosity; D015992:Body Mass Index; D017536:Carotid Artery, Common / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D006339:Heart Rate; D006801:Humans; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D014280:Triglycerides / Q000097:blood; D017539:Tunica Intima / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D017540:Tunica Media / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D018608:Ultrasonography, Doppler
D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D002784:Cholesterol