I. Non-intervention risk factors
1. Age: The incidence of stroke increases with age, increasing 1-fold every 10 years after age 55. Most all strokes occur in patients over 65 years of age.
2. Gender: The incidence of stroke is approximately 30% higher in men than in women.
3. Family history.
4. Race may intervene in risk factor one. Hypertension: Hypertension is the most important risk factor for cerebral hemorrhage and cerebral infarction. A domestic study showed that for every 10 mmHg increase in systolic blood pressure, the relative risk of stroke increased by 49%, and for every 5 mmHg increase in diastolic blood pressure, the relative risk of stroke increased by 46%, after controlling other risk factors.
Recommendations: (1) Further strengthen the publicity and education efforts, it is recommended that blood pressure should be measured once a year for those ≥35 years old, and patients with hypertension should have their blood pressure measured frequently (at least once every 2-3 months) to adjust the dose of medication. (2) Hospitals at all levels should establish a system for measuring blood pressure in adults at the first visit; (3) Localities should actively create conditions to establish model communities of a certain size to regularly screen the population for hypertensive patients and provide appropriate treatment and follow-up. (4) For early or mild patients first use lifestyle change treatment, and those who still have poor results in 3 months should be treated with additional anti-hypertensive drugs.
II. Heart disease
The risk of stroke is more than 2 times higher in people with heart disease than in those without heart disease. The annual risk of stroke in patients with non-valvular atrial fibrillation is 3% to 5%, accounting for approximately 50% of thromboembolic strokes. Recommendations: (1) adults (≥40 years old) should have regular physical examination for early detection of heart disease; (2) patients diagnosed with heart disease should be actively treated by a specialist; (3) patients with non-valvular atrial fibrillation can be anticoagulated with Warfarin in hospitals where available, but the international normalized ratio (INR) must be monitored and controlled in the range of 2.0-3.0; for those aged >75 years, the INR should be 1.6~2.5 is appropriate; or oral aspirin 50~300mg/d, or other anti-platelet aggregation drugs. (4) Patients with high risk of coronary artery disease should also take small doses of aspirin 50~150mg/d, or other anti-platelet aggregation drugs.
(3) Diabetes mellitus.
Diabetes mellitus is an important risk factor for cerebrovascular disease. Patients with type II diabetes mellitus have a 2-fold increased risk of stroke.
Recommendations: (1) People with risk factors for cardiovascular and cerebrovascular disease should have regular blood glucose testing and, if necessary, glycated hemoglobin (HbA1c). The diagnostic criteria for diabetes mellitus are consistent with the Chinese guidelines for the prevention and treatment of diabetes mellitus. (2) Diabetic patients should first control their diet and strengthen physical exercise, and those whose blood glucose control is still unsatisfactory in 2~3 months should be treated with oral hypoglycemic drugs or insulin. (3) Diabetic patients should actively treat hypertension, control weight and lower cholesterol level.
IV. Dyslipidemia.
A large number of studies have confirmed that elevated serum total cholesterol (TC) and low-density lipoprotein (LDL); and reduced high-density lipoprotein (HDL) are closely related to cardiovascular disease (LDL is called the body garbage, HDL is the body scavenger). Recommendations: (1) People with dyslipidemia, especially those with hypertension, diabetes, smoking and other risk factors should first change their unhealthy lifestyles and have their blood lipids reviewed regularly. If lifestyle changes are not effective, medication should be used. (2) Patients with previous history of TIA, ischemic stroke or coronary artery disease and TC higher than 5 mmo1/L should be treated with statins, and those with increased TG should be treated with betaine.
V. Smoking.
Frequent smoking is a recognized risk factor for ischemic stroke. Its pathophysiological effects on the body are multifaceted, mainly affecting the systemic vascular and blood system, such as: accelerating atherosclerosis, increasing the level of fibrinogen, promoting platelet aggregation, and reducing the level of high-density lipoprotein. Long-term passive smoking can also increase the risk of stroke.
Sixth, alcohol consumption.
Evidence from population studies has shown that alcohol intake has a direct dose-related effect on hemorrhagic stroke. However, the relevance for ischemic stroke is still controversial. Recommendations: (1) Small amounts of alcohol are not recommended for prevention of cardiovascular disease in non-drinkers; alcohol should be avoided in pregnant women. (2) Alcohol consumption should be moderate and not excessive; the daily alcohol content should not exceed 20-30g for men and 15-20g for women. It is believed that alcohol can increase the number of platelets in the blood and poorly regulate cerebral blood flow, which can lead to hypertension, arrhythmia and hyperlipidemia, thus increasing the risk of stroke.
VII. Carotid artery stenosis.
Some foreign studies found that 7% to 10% of men and 5% to 7% of women over the age of 65 have carotid stenosis greater than 50%. Recommendations: (1) For patients with asymptomatic carotid stenosis, surgical treatment or endovascular intervention is generally not recommended, and antiplatelet agents such as aspirin or statins are preferred. (2) For patients with severe carotid stenosis (>75%), with frequent attacks of symptoms and poor drug control, carotid endarterectomy or endovascular intervention can be considered where available (but the decision must be made after a thorough analysis and discussion based on the wishes of the patient and family, the presence of other comorbidities and the patient’s physical condition before surgery).
VIII. Obesity.
A prospective study of 10 populations in China showed that the relative risk of ischemic stroke in obese people was 2.2. Several large studies in recent years have shown that abdominal obesity is more closely related to stroke than increased body mass index (BMI) or homogeneous obesity.
IX. Hyperhomocysteinemia.
It is prevalent in Chinese. Vitamin B12 and folic acid deficiency is an important factor inducing elevated plasma homocysteine (Hcy). Chronic renal insufficiency may also be a cause of elevated Hcy plasma concentrations. possible mechanisms of Hcy-causing cerebrovascular disease: 1. its toxic effects on cerebrovascular endothelial cells and increased platelet adhesion in the blood are related. Stamler et al. placed vascular endothelial cells in a solution high in Hcy and found that Hcy hindered the production of endothelial-induced relaxing factor nitric oxide.3. The oxidation of Hcy can also produce free radicals and hydrogen peroxide, which contribute to the oxidation of low-density cholesterol and increase the formation of foam cells, resulting in the thickening of the inner wall of blood vessels and leading to the development of occlusive cerebrovascular disease.4. Hcy was also found to stimulate proliferation of vascular smooth muscle cells, the latter being an important factor in the formation of atherosclerosis.5. On the other hand, Rodgers et al. found in their study that Hcy and its derivatives increase the production of platelet coagulation oxidants, thereby affecting platelet aggregation and coagulation factor V activity.6. 6. HCY may act as a thrombogenic agent, affecting thrombomodulin expression and protein C activity. Recommendations for hyperhomocysteinemia: Folic acid in combination with vitamins B6 and B12 has been shown to significantly reduce increased plasma cysteine levels.
X. Metabolic syndrome.
The core of the metabolic syndrome is insulin resistance.
The causes of insulin resistance are both hereditary (genetic defects) and acquired (environmental factors). Genetic defects can occur in various pathways of insulin receptor and post-receptor signaling, and acquired factors include insulin receptor antibodies, certain glucagon hormones, islet amyloid polypeptides, chronic hyperglycemia, hyperlipidemia toxicity, westernized lifestyle, and poor dietary structure.
In a general sense, insulin resistance means a decrease in insulin’s ability to promote glucose utilization. The increase in blood glucose level caused by the decrease in glucose utilization, followed by a compensatory increase in insulin, manifests as hyperinsulinemia, which is a direct manifestation of insulin resistance.
XI. Seasons and climate.
The relationship between season and climate stroke onset and season and climate has long attracted attention. The literature mostly suggests that the onset of cerebral hemorrhage is more frequent in winter, while the onset of cerebral infarction is more frequent in summer. In Beijing hospitals, many old leaders of the central government often go to the hospital for preventive treatment by infusion when the seasons change, to which the experts of the Department of Neurology do not object.
XII. The role of genetics.
The role of genetic factors regarding stroke remains unclear. Most authors believe that cerebrovascular disease is multi-factorial inheritance, and its heritability is greatly influenced by environmental factors. Case-control studies conducted in 7 cities and 21 provinces in China have shown that positive cerebrovascular disease and family history of hypertension are clear risk factors for both hemorrhagic and ischemic strokes. However, studies of Japanese immigrants to date have demonstrated that environmental factors are more important than genetic factors. Therefore, we should not give too much importance to genetic factors and do nothing to prevent stroke, but should actively prevent it by changing environmental factors. The control of the external environment depends on the subjective efforts of people. For example, the control of emotion, regularity of life, reasonable diet and physical exercise, avoid obesity, reduce salt, do not smoke, drink less alcohol, do not be too tired, etc. all depend on their own control and arrangement.
XIII. Other risk factors.
Lack of physical activity (sedentary); unreasonable diet and nutrition; oral contraceptives; increased blood coagulability, is a pro-coagulation risk factors, can raise blood pressure. Blood rheology abnormalities: 1. Increased high cut viscosity suggests reduced red blood cell deformability, which means increased red blood cell rigidity. Treatment with drugs that improve red blood cell deformation, such as hexaconitine. 2. Increased low-cut viscosity indicates increased erythrocyte pressure and increased erythrocyte aggregation, which can be treated with trimethoprim and low molecular dextran. 3. If the high cut viscosity and low cut viscosity are increased at the same time, use drugs to improve red blood cell deformation and red blood cell aggregation at the same time. 4. If the platelet aggregation rate exceeds 50% (normal 20% to 50%), give anti-platelet drugs for at least one week. In addition, there is a history of slow branching, emphysema, pulmonary heart disease, major surgery, and trauma. Vegetarian fatty diet, extroverted personality, multiple births in women, type A blood personality.