The pathological basis of multi-organ damage in diabetes is macroangiopathy and microangiopathy. Among them, macroangiopathy is closely related to cardiovascular and cerebrovascular disease, and is the main cause of death or disability in diabetes.
1, diabetes affects cardiovascular from 4 aspects:
1.1 Disorders of lipid metabolism in diabetes mellitus
The lipid metabolism disorder of diabetes is not or not exactly a secondary result of the disorder of glucose metabolism, but probably a primary event. cholesterol concentration in VLDL; elevated cholesterol/lecithin ratio in VLDL; increased lipoprotein glycation and lipoprotein oxidation. These abnormalities increase the risk of macrovascular disease, and ATP III describes diabetes as a “classical risk” for coronary artery disease.
1.2 Hypertension in diabetes mellitus
WHO data show that the prevalence of diabetes is about 10-20% in hypertensive patients worldwide, 30% in the United States, 50% in Canada, and 50% in China, which is similar to Canada. At present, there are more than 100 million people with hypertension, nearly 100 million people with hyperglycemia, and more than 20 million people with hyperglycemia combined with hypertension in China.
1.3 Cardiovascular plant neuropathy of diabetes mellitus
It can cause postural hypotension, various heart rhythm disorders and sensory disorders, such as the absence of nociception, which makes coronary heart disease lack of angina (painless myocardial ischemia) and myocardial infarction lack of pain, which becomes painless myocardial infarction.
1.4 Microangiopathy in diabetes mellitus
Microangiopathy of the myocardium in diabetes causes ischemia, hypoxia and nutritional disorders of the myocardium, leading to cardiomyopathy.
Due to the above four effects, the following characteristics of cardiovascular complications of diabetes mellitus are found in clinical practice.
(1) Earlier appearance of atheromatous plaques with extensive and severe lesions;
(2) Poor efficacy of reperfusion therapy, especially the high incidence of reocclusion in PTCA (with or without stent);
(3) Because myocardial ischemia in diabetes can be asymptomatic, it is often not diagnosed early;
(4) Endothelial dysfunction and thrombogenic tendencies in diabetes: plaque instability and susceptibility to thromboembolism;
(5) myocardial microangiopathy and energy metabolism disorders, predisposing to heart failure;
(6) Cardiac vegetative neuropathy, prone to cardiac rhythm disturbances;
(7) Often combined with hypertension;
(8) significantly increased risk of stroke and peripheral vascular disease;
2, DCCT, UKPDS, ACCORD, ADVANCE, VADT five major evidence-based medical research insights
2.1 Eliminate the “metabolic memory effect”, the earlier the blood glucose control, the better
The DCCT study in the United States from 1983 to 1993 observed 1441 cases of type 1 DM for 6.5 years and found that intensive glycemic control was effective in reducing the risk of diabetic microangiopathy. Since then, 93% of patients have participated in the Epidemiology of Diabetes Interventions and Complications (EDIC) study.
Animal studies found no pathological histological changes in the eyes of diabetic dogs during the first 2.5 years of sustained glycemic elevation, but significant retinopathy occurred during the subsequent 2.5 years of normal glycemic control. This phenomenon of microangiopathy occurring and developing in the subsequent normoglycemic internal environment is called the “metabolic memory” of hyperglycemia. The objective existence of “metabolic memory” effect of hyperglycemia indicates that in order to achieve the best effect in the prevention and treatment of chronic complications of diabetes, the control of blood glucose needs to be carried out early, no matter for macrovascular complications or for microvascular complications.
2.2 The goal and speed of glycemic control should be individualized
Before 2010, there were unified diabetes diagnosis standard and unified diabetes typing standard, but there was no unified glycemic control standard. The core of this once called “cross-century controversy” is actually whether further strict glycemic control can prevent macrovascular complications?
The ACCORD, the Intensive Glycemic Control and Cardiovascular Regression Study and the Veterans American Diabetes Study (VADT), as well as the UKPDS and DCCT’s EDIC studies, attempted to address this dilemma. Instead, it increased diabetic deaths, causing the study to be stopped midway through.
These studies suggest that there are therapeutic risks to intensive glycemic control in people of advanced age, long duration of disease, and existing cardiovascular complications; HbA1c targets need not be too strict in patients with a history of severe hypoglycemia, limited survival, children, and a long history of disease; in a word the goals and speed of glycemic control should be individualized.
2.3 Beyond glucose lowering, all-round treatment of diabetes
There is a “barrel effect” in the overall treatment effect of diabetes mellitus. Hyperglycemia, hypertension, hyperlipidemia, insulin resistance, hyperuricemia, high body weight, high blood viscosity and various complications are the multiple planks of a barrel, and water always flows from the upper edge of the shortest plank. Therefore, it is not enough to just control blood sugar, but should go beyond sugar reduction and deal with diabetes in all aspects. It should not only lower sugar, but also lower lipids, lower blood pressure, improve insulin resistance and correct hyperinsulinemia, correct abnormal blood clotting mechanism and avoid obesity, etc.