Summary
Type 2 diabetes mellitus (T2DM) increases the risk of coronary thrombosis and both
conditions are associated with altered fibrin clot properties. However, the influence
of T2DM on fibrin clot properties in patients with coronary artery disease (CAD) remains
unclear. We aimed to investigate the influence of T2DM on fibrin clot properties in
patients with CAD. Fibrin clot structure and fibrinolysis were investigated in 581
CAD patients (148 with T2DM) using turbidimetric assays, confocal and scanning electron
microscopy. Clots made from plasma and plasma-purified fibrinogen were studied, and
plasma levels of inflammatory markers were analysed. T2DM patients had increased clot
maximum absorbance compared with non-diabetic patients (0.36 ± 0.1 vs 0.33 ± 0.1 au;
p=0.01), displayed longer lysis time (804 [618;1002] vs 750 [624;906] seconds; p=0.03)
and showed more compact fibrin structure assessed by confocal and electron microscopy.
Fibrinogen levels were elevated in T2DM (p< 0.001), but clots made from purified fibrinogen
showed no differences in fibrin properties in the two populations. Adjusting for fibrinogen
levels, T2DM was associated with C-reactive protein and complement C3 plasma levels,
with the former correlating with clot maximum absorbance (r=0.24, p< 0.0001) and the
latter with lysis time (r=0.30, p< 0.0001). Independent of fibrinogen levels, females
had more compact clots with prolonged lysis time compared with males (all p-values<
0.001). In conclusion, T2DM is associated with prothrombotic changes in fibrin clot
properties in patients with CAD. This is related to quantitative rather than qualitative
changes in fibrinogen with a possible role for inflammatory proteins.
Keywords
Fibrin clot - fibrinolysis - coronary artery disease - type 2 diabetes mellitus -
inflammation