Arterial sites with low wall shear stress (WSS) are more prone to
the development of atherosclerotic plaques, as was observed in
carotid arteries in subjects with atherosclerosis risk factors.
Type 2 diabetes mellitus (DM), hypertension, hyperlipidemia and
other components of the metabolic syndrome, are associated
with high risk for symptomatic cerebrovascular disease. It was
shown by others that untreated type 2 DM is associated with
lower WSS in common carotid arteries. However, the
cardiovascular risk of type 2 DM could be modified by therapy.
The aim of our study was to test the hypothesis that treated type
2 DM subjects with metabolic syndrome still have lower WSS in
common carotid arteries than healthy controls. We enrolled 26
compensated DM subjects with metabolic syndrome, treated by
metformin, statins and ACEI for more than 6 months, and 22
aged-comparable healthy controls. Wall shear rate (WSR) was
used as a measure of WSS. A linear 3-11 MHz probe was used to
measure blood velocity and internal diameter in the common
carotid arteries. We compared observed values of WSR adjusted
for age by ANCOVA. Wall shear rate was significantly lower in DM
group than in control subjects: peak (systolic) values of wall
shear rate were 410±130 s-1 vs. 487±111 s-1 (p<0.005). DM
subjects had significantly lower WSR, because of both thinner
lumen and slower blood flow velocities. Lower WSR was
accompanied by higher IMT (0.73±0.12 mm vs. 0.64±0.11 mm,
p<0.001). Treated subjects with compensated type 2 DM with
metabolic syndrome still have atherogenic hemodynamic profile.
These findings might help to understand faster progression of
atherosclerosis in diabetic subjects with metabolic syndrome
despite up-to-date medication.
Relationship between intima-media thickness of the common carotid artery and arterial stiffness in subjects with and without type 2 diabetes: a case-series report