AIM: Stromelysin (MMP3), through its action on collagen and other matrix
metalloproteinases, influences arterial wall remodeling. In healthy subjects, the
5A/6A polymorphism located in the promoter of the MMP3 gene is associated with
common carotid remodeling, 6A/6A subjects having increased arterial diameter,
wall thickness (intima-media thickness, IMT) and decreased wall shear stress
(WSS). In the present study, we have investigated the influence of the 5A/6A
polymorphism on common carotid remodeling in subjects with diabetes mellitus.
METHODS: Diabetic subjects (N.=136) and age-matched healthy male controls
(N.=101) have been studied. Common carotid diameter, IMT and flow velocity have
been measured by echo-Doppler. Blood viscosity has been measured by a cone/plate
viscometer. WSS has been calculated.
RESULTS: Diabetic patients had increased common carotid diameter, IMT, and
decreased flow velocity and WSS (all P<0.05), compared with controls. In
controls, subjects homozygous for the 6A allele had increased diameter, IMT and
decreased WSS. In diabetics, no difference was observed in vascular parameters
among the three genotypes.
CONCLUSION: The 5A/6A polymorphism of the MMP3 gene influences arterial
remodeling of the common carotid artery in healthy subjects, but not in patients
with diabetes mellitus. Therefore, the significance of the 5A/6A polymorphism as
a marker of risk in this high cardiovascular risk population seems to be somehow
blunted