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| Why is diabetes easy to cause cardiovascular disease? |
Most people with diabetes can be classified into two major categories of pathogenesis. One type (type 1) is the absolute lack of insulin secretion, and the other type (type 2) is a combination of insulin resistance and insulin-compensatory secretory response. Because insulin is an important substance for lowering blood sugar secreted by the human body, in general, type 1 mainly refers to the problem of the formation of this substance, which does not reach a sufficient level. Type 2 mainly refers to the substance that acts on insulin is resistant to insulin, leading to insulin. Can not play the role of lowering blood sugar.
In addition, a small number of diabetic patients have their own unique etiology and pathogenesis, which can be attributed to other special types. I won't go into details here.
The presence of diabetes often leads to the emergence of many complications, manifested at the micro level, which is manifested as the pathological changes of the tissue.
At present, the most serious pathological changes that threaten the lives of diabetic patients are cardiovascular diseases. More than 70% of patients die from various complications of cardiovascular disease; vascular lesions are very extensive, regardless of large, medium, small blood vessels, arteries, capillaries and veins. Can be involved, often complicated by many organ lesions, especially cardiovascular, kidney, fundus, nerves, muscles, skin and other microvascular lesions.
1. Arterial: Atherosclerosis is seen in more than half of the patients, the incidence is not limited by age, mainly involving the aorta, coronary artery, cerebral artery, etc., often causing serious complications of heart, brain and kidney and causing death. Hardening of the surrounding arteries, especially the dorsal artery of the lower extremities, can cause gangrene.
2. Microvessels: including capillaries, arterioles, and venules. Microvascular lesions in diabetes are characterized by capillary microscopy thickening under light microscopy and electron microscopy; normal basement membrane thickness is about 80-250 nm, and basement membrane thickness is increased in diabetic patients. The thickness can reach 500-800nm. Such microvascular lesions are often accompanied by microcirculation abnormalities, which are the pathological basis of multiple organ diseases. Its distribution is very extensive, especially microvessels such as glomeruli, fundus, nerves, myocardium, muscles, etc., causing renal lesions, fundus lesions, neuropathy and myocardial muscle lesions, which become the main factors determining the prognosis of patients.
In addition, in addition to the heart wall internal and external coronary artery and its internal branches are extensive atherosclerosis with myocardial infarction and other diseases, myocardial lesions have also been confirmed, there are many autopsy and a variety of animal models and so on.
The role of diabetes in microvascular and arterial lesions is not exactly the same.
In the microvascular aspect, long-term hyperglycemia caused by diabetes is the central link of microvascular disease, and its main mechanism involves the following aspects:
1. Hyperglycemia and terminal glycosylation products
2. Polyol metabolism bypass enhancement
3. Hexosamine pathway enhancement
4. Protein kinase C activation
5. Hemodynamic changes
All of the above pathways can induce vascular inflammatory reaction, tissue ischemia and hypoxia through different and complex biochemical reactions, and then participate in the occurrence and development of microvascular disease.
In terms of arteries, the main focus is on vascular lesions caused by mechanisms such as insulin resistance syndrome, inflammation, immune response, and endothelial cell damage. Each pathway also covers a large number of complex biochemical reaction mechanisms.
Therefore, according to the current research results, diabetes can mediate the development of cardiovascular disease through a variety of ways.
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