Summary
We evaluated the plasma concentrations of soluble adhesion molecules and platelet-derived
microparticles (PMP) in patients with non-insulin dependent diabetes mellitus (NIDDM)
and studied the effect of cilostazol on PMP generation. There were differences in
the levels of soluble adhesion molecules between NIDDM patients (N = 43) and the control
subjects (N = 30) (soluble thrombomodulin: 11.5 ± 5.3 vs. 7.0 ± 1.2 TU/ml, p<0.0001;
soluble vascular cell adhesion molecule-1: 708 ± 203 vs. 492 ± 113 ng/dl, p<0.0001;
soluble intercellular cell adhesion molecules-1: 274 ± 65 vs. 206 ± 48 ng/dl, p<0.0001;
soluble P-selectin: 194 ± 85 vs. 125 ± 43 ng/dl, p<0.0001). There were also differences
in the levels of PMP and platelet activation markers between NIDDM patients and the
controls (PMP: 943 ± 504 vs. 488 ± 219/10 4 plt, p<0.0001; platelet CD62P: 9.2 ± 4.6
vs. 4.4 ± 4.3%, p<0.001; platelet CD63: 10.2 ± 4.5 vs. 4.5 ± 3.3%, p<0.0001; platelet
annexin V: 9.1 ± 3.9 vs. 5.3 ± 3.8%, p<0.001). To study the release of PMP into plasma,
a modified cone-and-plate viscometer was used. Increased release of PMP from platelets
was observed in diabetic plasma compared to normal plasma under high shear stress
conditions (2,672 ± 645 vs. 1,498 ± 386/104 plt, p<0.05). Therefore, one cause of PMP elevation in NIDDM may be high shear stress.
The levels of PMP, activated platelets, and soluble adhesion molecules all decreased
significantly after treatment with cilostazol. These results suggest that cilostazol
may be useful for the inhibition of both PMP-dependent and -independent vascular damage
in NIDDM.