1.What is hypertension?
Hypertension, also known as primary hypertension, is a syndrome in which elevated arterial blood pressure is the main clinical manifestation; hypertension is an important cause and risk factor for a variety of cardiovascular and cerebrovascular diseases, affecting the structure and function of important organs such as the heart, brain and kidney, eventually leading to the failure of these organs, and is still one of the main causes of death from cardiovascular disease.
2.How is blood pressure expressed?
Blood pressure is the lateral pressure exerted on the walls of blood vessels by the flow of blood through them. Blood pressure is expressed as systolic pressure (“high pressure”) / diastolic pressure (“low pressure”). Also pulse pressure difference = systolic pressure (high pressure) – diastolic pressure (low pressure).
Systolic pressure: Systolic pressure is the lateral pressure of blood against the walls of blood vessels when the heart is contracting; diastolic pressure is the lateral pressure on the walls of blood vessels when the heart is diastolic. When a doctor records blood pressure, if it is 120/80mmHg, then 120mmHg is the systolic pressure and 80mmHg is the diastolic pressure. According to the international unit “kPa” (kilopascal), the conversion method: 1mmHg (mmHg) = 0.133kPa (kilopascal), so 120/80mmHg is equivalent to 16/10.6kPa.
3.How to measure blood pressure? What should I pay attention to?
Currently blood pressure is expressed by the value measured by a sphygmomanometer on the brachial artery in mmHg (millimeters of mercury) or kPa (kilopascals).
The measurement of blood pressure is important for the diagnosis of hypertension and therefore the following principles should be observed.
(1) Patients should perform it in a resting and sedentary state and try to exclude the influence of environmental and emotional factors. Blood pressure in the recumbent position may be biased higher than that in the sitting position, while blood pressure in the standing position may be biased lower than that in the sitting position. For each position change, 2 min is required before measuring the changed blood pressure, and the deviation of blood pressure value for each position is <5%.
(2) Accurate blood pressure measurement is made with the brachial artery as the standard and the cuff to 1 to 2 cm above the transverse stripe of the elbow fossa. the cuff tries not to compress the stethoscope head, and after playing to the highest systolic pressure on 20 mmHg of gas, the gas is slowly released so that the silver mercury column slides at a constant rate and 2 to 6 mmHg/s. Blood pressure readings are taken in millimeters of mercury (mmHg) and then changed to kPa units.
(3) The choice of blood pressure measurement, the mercury column table is the best, but also the brachial artery of the electronic blood pressure meter, avoid the use of radial artery and finger artery electronic blood pressure measurement instrument.
4.What is the cause of hypertension?
The causes of hypertension are not well understood, but may be related to the following factors: heredity, smoking, alcoholism, lack of exercise, excessive salt intake, overweight, and mental stress.
The first is hereditary hypertension, which is common in middle-aged and elderly people. Middle-aged and elderly people are prone to hypertension, of which more than 40% have a history of hypertension in their parents; children without hypertension have only a 3% chance of developing hypertension. More than 60% of the elderly population suffers from significant cardiovascular disease, with hypertension causing the majority of associated cardiovascular disease. Each year, 1.5 million people nationwide suffer strokes caused by hypertension.
People who are emotionally unstable are also prone to hypertension. Emotional, nervous people, irritable, always looking ahead, repeatedly thinking and difficult to make up their minds, as well as over-anxious, engaged in mental work and high tension, prone to hypertension. Such people, such as hypertension, drug treatment is often ineffective.
Overweight and obesity are important reasons for susceptibility to hypertension. Obesity can not only cause hypertension, but also easily lead to coronary heart disease, cholecystitis, arthritis and many other systemic diseases. Most obese people are sleepy and have a good appetite, which can easily form a vicious circle. The effective way to reduce weight is to participate in regular exercise and proper control of diet.
Excessive intake of salt in the diet is more likely to suffer from hypertension. One of the reasons why people in the north are prone to hypertension is related to a salty diet. The main component of salt is sodium chloride, eating too much salt will lead to excessive sodium in the body, vascular resistance increases, cardiovascular burden increases, prompting an increase in blood pressure.
Smoking and long-term alcohol consumption, is also the main cause of hypertension. Smoking is the most significant risk factor for hypertension and coronary heart disease. Long-term heavy smoking can increase the heart rate and blood pressure. The incidence of cardiovascular accidents and myocardial infarction is 2-4 times higher than normal in mentally stressed and type A personality smokers. In addition, in recent years, it has been confirmed that long-term heavy drinking, especially those who drink easily, often combined with hypertension, obesity, hyperlipidemia and hyperglycemia.
Diabetic patients have 30 times higher chance of developing arteriosclerosis and hypertension than normal people. If diabetes and hypertension coexist, the risk of stroke and myocardial infarction is 2-4 times higher than normal; elevated levels of high blood lipids, especially low-density lipoprotein, are directly proportional to the incidence of hypertension, coronary heart disease and myocardial infarction.
5.How to diagnose hypertension?
In the absence of anti-hypertensive drugs, systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg, hypertension is classified into 1, 2, 3 according to blood pressure level. Systolic blood pressure ≥140 mmHg and diastolic blood pressure <90 mmHg were classified as simple systolic hypertension alone. Patients with a previous history of hypertension and currently on antihypertensive medication should be diagnosed with hypertension even though their blood pressure is below 140/90 mmHg. Blood pressure is a clinical manifestation that fluctuates up and down influenced by various factors such as environment, emotion, medication, and body position. Therefore, to determine an increase in blood pressure, the interference of the above factors should be minimized or excluded, and hypertension can be diagnosed after 3 resting blood pressure measurements on the same day (after sitting still for 5-15 min) ≥ 18.7/12.0 kPa (140/90 mmHg)).
The diagnosis of hypertension should include the following.
Confirmation of hypertension, i.e. whether the blood pressure is indeed higher than normal, except for symptomatic hypertension ;
Staging and grading of hypertension;
Estimation of important organ function of heart, brain and kidney;
The presence of combined conditions that can affect the development and treatment of hypertension, such as coronary heart disease, diabetes mellitus, hyperlipidemia, hyperuricemia, chronic respiratory diseases, etc.
6.What is the current status of hypertension in China?
The prevalence of hypertension in China is 18.8% among residents aged 18 and above, with an estimated 160 million people affected nationwide. Compared with 1991, the prevalence has increased by 31%.
Hypertension in our population has the following characteristics.
Three high: high prevalence, high disability rate and high mortality rate
Three low: low awareness rate, low treatment rate, low control rate
Awareness rate: 36.3% in urban areas, 13.7% in rural areas;
Treatment rate: 17.4% in urban areas, 5.4% in rural areas;
Control rate 4.2% in urban areas, 0.9% in rural areas
7.What is the prevalence of hypertension?
The general rules of hypertension prevalence are.
(1) The prevalence of hypertension is directly proportional to age;
(2) The prevalence of hypertension in women is lower than that in men before menopause and higher than that in men after menopause;
(3) There are geographical distribution differences. The general pattern is that high latitude (cold) areas are higher than low latitude (warm) areas. High altitude areas are higher than low altitude areas;
(4) Seasonal differences in the same population, with a higher prevalence in winter than in summer;
(5) It is related to dietary habits. The higher the per capita salt and saturated fat intake, the higher the average blood pressure level. Regular heavy drinkers have higher blood pressure levels than non-drinkers or low drinkers;
(6) Positive correlation with the level of economic and cultural development. The more developed the economy and culture, the higher the blood pressure level per capita;
(7) Prevalence is positively correlated with obesity and mental stress, and negatively correlated with physical activity level;
(8) There is a genetic basis for hypertension. There is a significant correlation between blood pressure in the immediate family (especially between parents and biological children). There are some group differences in blood pressure between different races and ethnic groups.
8.What are the causes of secondary hypertension?
The specific cause of hypertension can be identified in about 5% to 10% of adults with hypertension. A simple screening for secondary hypertension can be performed by clinical history, physical examination and routine laboratory tests.
(1) Renal parenchymal hypertension
Renal parenchymal hypertension is the most common form of secondary hypertension. (Chronic glomerulonephritis is the most common; others include structural nephropathy and obstructive nephropathy.) Routine urinalysis should be performed at the initial consultation in all hypertensive patients to screen for the exclusion of renal parenchymal hypertension. If a mass is palpated in the upper abdomen bilaterally during physical examination, polycystic kidney should be suspected and an abdominal ultrasound examination should be performed to help clarify the diagnosis. Measurement of urine protein, red blood cells and white blood cells and blood creatinine concentration can help to understand glomerular and tubular function.
(2) Renal vascular hypertension
Renal vascular hypertension is the second cause of secondary hypertension. Abroad, 75% of patients with renal artery stenosis are due to atherosclerosis (especially in the elderly). In our country, atherosclerosis is an important cause of renal artery stenosis in young people. Fibromuscular dysplasia is less common in our country. Signs of renal artery stenosis are vascular murmurs heard in the umbilicus that conduct unilaterally, but are uncommon. Laboratory tests may reveal hyperrenin, hypokalemia. Progressive decompensation of renal function and reduction in kidney volume are the main manifestations in advanced patients. Ultrasound renal artery examination, enhanced spiral CT, magnetic resonance angiography, and digital subtraction are helpful for diagnosis. Color Doppler ultrasonography of the renal arteries is a noninvasive screening tool with high sensitivity and specificity. Renal arteriography can confirm the diagnosis.
(3) Pheochromocytoma
Pheochromocytoma is a rare form of secondary hypertension. Urine and blood catecholamine testing can clarify the presence of catecholamine hypersecretion. Ultrasound or CT examination can make a local diagnosis.
(4) Primary aldosteronism
Testing of blood potassium levels is used as a screening method. Significantly low plasma renin activity (<1ng/ml/h) after discontinuation of drugs that affect renin (e.g., b-blockers, ACEI, etc.) and significantly elevated plasma aldosterone levels suggest the disease. A ratio of plasma aldosterone (ng/dl) to plasma renin activity (ng/ml/h) greater than 50 is highly suggestive of primary aldosteronism. CT/MRI examination helps to determine whether it is an adenoma or hyperplasia.
(5) Koch syndrome
80% of cases of Koch syndrome are associated with hypertension. The typical body shape of the patient often suggests this syndrome. A reliable indicator is the measurement of 24-hour urinary hydrocortisone levels, which are highly suggestive of the disease at >110 nmol/L (40 ng).
(6) Drug-induced hypertension
Drugs that elevate blood pressure include: licorice, oral contraceptives, steroids, NSAIDs, cocaine, amphetamines, erythropoietin, and cyclosporine.
9.What is the target for lowering blood pressure in hypertension?
The correlation between cardiovascular disease risk and blood pressure is continuous, and there is no minimum threshold in the normal blood pressure range. Therefore, the goal of anti-hypertensive treatment is to restore blood pressure to normal levels. Numerous studies have shown that after antihypertensive treatment, the lower the blood pressure level, the greater the risk reduction, provided that the patient can tolerate it.
The primary treatment goal for patients with hypertension is to minimize the overall risk of long-term cardiovascular morbidity and mortality. This requires treatment of all well-defined reversible risk factors, including smoking, dyslipidemia, and diabetes mellitus, as well as reasonable control of coexisting clinical conditions along with treatment of hypertension.
Based on the available evidence, we recommend that blood pressure (both systolic and diastolic) should be strictly controlled to below 140/90 mmHg in patients with general hypertension; to below 130/80 mmHg in patients with diabetes and renal disease; and to below 150 mmHg in the elderly, with further reductions if tolerated.
10.How many aspects does the treatment of hypertension include?
The treatment of hypertension includes both non-pharmacological treatment and pharmacological treatment.
11.What are the non-pharmacological treatments for hypertension?
Non-pharmacological treatment includes promoting a healthy lifestyle and eliminating behaviors and habits that are detrimental to mental and physical health to reduce the risk of developing hypertension and other cardiovascular diseases, including.
(1) Weight reduction Calorie reduction, dietary balance, and increased exercise to maintain a body mass index of 20-24 kg/m2 , and a weight loss of 10 kg can reduce blood pressure by 5-20 mmHg;
(2) Dietary salt restriction In the north, the average daily salt intake per person will first be reduced to 8g, and then to 6g; in the south, it can be controlled to less than 6g. Blood pressure can be reduced by 2-8mmHg.
(3) Reduce dietary fat Total fat <30% of total calories, saturated fat <10%, increase fresh vegetables 400-500g daily, fruits 100g, meat 50-100g, fish and shrimp 50g, eggs 3-4 per week, milk 250g daily, oil 20-25g daily, less sugar and sweets.
(4) Increase and maintain appropriate physical activity Generally, exercise 3-5 times a week, lasting 20-60 minutes each time. If you feel good about yourself and maintain your ideal weight after exercise, it indicates that the amount and type of exercise is appropriate. Blood pressure can be reduced by 4-9 mmHg;
(5) Maintain an optimistic state of mind and improve stress capacity Improve the ability of the population to prevent disease on their own through education and counseling. Promote the selection of sports, painting and other cultural activities suitable for individuals, increase social opportunities for the elderly, and improve the quality of life.
(6) Quit smoking and limit alcohol Do not smoke; do not advocate drinking alcohol; if drinking alcohol, men should not drink more than 25 grams of alcohol per day, that is, less than 100-150 ml (2-3 taels) of wine, or less than 250-500 ml (half a catty-1 catty) of beer, or less than 25-50 ml (0.5-1 taels) of white wine; women should reduce the amount by half, and pregnant women should not drink alcohol. Do not advocate drinking highly potent alcohol. Patients with hypertension and cardiovascular disease should abstain from alcohol. Blood pressure can be reduced by 2-4mmHg.
12.What are the principles of drug treatment for hypertension?
Antihypertensive drug therapy can effectively reduce the morbidity and mortality of cardiovascular diseases and prevent the occurrence and development of stroke, coronary heart disease, heart failure and nephropathy. The common action of antihypertensive drugs is to lower blood pressure. Different classes of antihypertensive drugs may have differences in action other than lowering blood pressure, and these differences are the main reference when selecting drugs in different patients.
From the current understanding, the following principles should be adopted for lowering blood pressure in the case of hypertension.
(1) Use a smaller effective dose to obtain the possible efficacy with minimal adverse effects, and if effective and unsatisfactory, gradually increase the dose to obtain the best efficacy.
(2) In order to effectively prevent target organ damage, a stable blood pressure within the target range for 24 hours per day is required, which prevents sudden death, stroke or heart attack from a low blood pressure at night to a sudden increase in blood pressure in the early morning. To achieve this, it is best to use a drug that is administered once a day and has a continuous 24-hour effect. One of the hallmarks of this is a trough ratio >50%, which also increases compliance with treatment.
(3) In order to increase the antihypertensive effect without increasing the adverse effects, the combination of two or more antihypertensive drugs can be used if the efficacy of monotherapy with low doses is not satisfactory. In fact, grade 2 or higher hypertension often requires a combination of antihypertensive drugs in order to achieve the target blood pressure.
13.What are the categories of anti-hypertensive drugs?
Currently, the following five categories of drugs are commonly used to lower blood pressure, namely diuretics, b-blockers, angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), and calcium antagonists.
14.What is the strategy of antihypertensive treatment?
Most patients with hypertension (but not all) should gradually lower their blood pressure to target levels over a period of weeks.
To achieve these goals, most patients will need to take more than one antihypertensive medication.
Depending on the baseline blood pressure level and the presence or absence of co-morbidities, it is reasonable to start treatment for hypertension with a low dose of a single drug or a low dose combination of two drugs.
Both regimens have advantages and disadvantages.
15.How to choose antihypertensive drugs?
The benefit of antihypertensive treatment mainly comes from the antihypertensive itself
There is evidence that different types of drugs in the same class act differently and have different efficacy for certain special groups of patients.
Adverse drug reactions vary and there are significant individual differences.
Diuretics, beta-blockers, calcium antagonists, ACE inhibitors, and angiotensin receptor antagonists and low-dose combination agents are several major antihypertensive drugs that can be used as initial and maintenance medications for antihypertensive therapy.
The emphasis on a preferred drug for BP lowering is outdated, as most patients are on two or more drugs to bring BP to target levels.
Available evidence suggests that the choice of medication is influenced by multiple factors, including.
(1) the patient’s previous medication experience
(2) price of the drug
(3) Risk level, presence of target organ damage, clinical cardiovascular disease, renal disease, or diabetes mellitus
(4) the patient’s wishes
19, the combination of antihypertensive drugs
In order to maximize the effect of treatment of hypertension, it is necessary to lower blood pressure to a greater extent, to do this monotherapy is often unable to achieve, single drug to increase the dose is prone to adverse reactions. Randomized clinical trials have demonstrated that most hypertensive patients require two or more antihypertensive drugs for blood pressure control, and that there is a need and value in combining drugs. When combined, the dose of each drug is not large, and the therapeutic effects of the drugs should be synergistic or at least additive, and their adverse effects can cancel each other out or at least not overlap or add up. The number of drug species used in combination should not be excessive to avoid complex drug interactions.
The results of available clinical trials support the combination of the following classes of antihypertensive drugs.
(1) diuretics and ACEI or ARB
(2) Calcium antagonists (dihydropyridines) and b-blockers
(3) Calcium antagonist and ACEI or ARB
(4) Calcium antagonists and diuretics
(5) a-blocker and b-blocker
Other combinations may be used if necessary, including centrally acting agents such as a2 agonists, midazolam receptor modulators, and ACEIs with ARBs.
Many patients require more than two drugs in combination and may refer to the above combinations.
Combination of drugs can be done in two ways.
(1) Adopt the on-demand dosing prescription of each drug, which has the advantage that the variety and dose can be adjusted according to clinical needs.
(2) Adopting fixed ratio compounding, which has the advantage of convenience and is conducive to improving patient compliance.