VII.5. Type 2 diabetes mellitus (T2DM)

T2DM is a risk factor for atherosclerosis, CHD and CVD. Insulin resistance is related to an increased risk of CVD.

An increased blood Glu level may contribute to the development of an endothelial dysfunction (it increases oxidative stress and membrane damage) and to atherogenesis (decreased NO production).

In many patients, T2DM is diagnosed only in connection with a cardiovascular event.

The development of T2DM is a comparatively long process (Fig. 25).

Figure 25. The development of diabetes mellitus

(based on Kendal, DM, Bergenstal, RM: International Diabetes 2005)

IGT (which is regarded as ”prediabetes”) without chronic hyperglycemia causes a twofold, while with hyperglycemia it causes a threefold increase in the risk of CAD. In view of the increased risk factors, the American Diabetes Association decreased the blood Glu range of DM for early diagnosis of the disease: 

The range of FPG is 100-125 mg/dl, the range in DM has been decreased from 140 mg/dl to 126 mg/dl, and the range of IFG has been decreased too (Fig. 26).

Figure 26. Complications following diabetes mellitus

(ADA, Diabetes Care, 2003:26:3160-3167
TSAO PS et al.: Arterioscler Thromb Vasc Biol.: 1998, 18:947-953
Hsueh WA et al. Am.J. Med. 1998: 105(1A):4S-14S)

Appropriate control of the blood Glu level decreases the risk of the development of microvascular damage. Anti-atherogenic treatment is needed to decrease macrovascular risk factors.  

Diabetes associated with increased PKC and ET-1 production enhances the development of vascular diseases.  

A high blood Glu level increases the production of advanced glycation product (AGE). Collagens and proteins are connected to Glu during the process, and because of the connection the protein structure and function change. The presence of AGE receptors has been demonstrated in various cells. A rise in AGE level increases coagulation, decreases the endothelial NO level, induces thickening of the vessel walls and changes their permeability.    

DM enhances almost all steps of coagulation and raises the thrombocyte activity. The levels of anticoagulant antithrombin III and protein C decrease and the levels of antiaggregation prostacyclins in the platelets decrease too.