Popular science ｜ The details that hypertension patients easily ignore ＂postprandial hypotension＂, how to intervene？

At present, hypertension has aroused widespread concern in society, but postprandial hypotension (PPH), a common symptom of the elderly, is often ignored by the public.

Clinically, we often hear some elderly people complain of dizziness, fatigue, drowsiness, blackness, and even angina pectoris, syncope, and falls after meals. In fact, many of these symptoms are caused by postprandial hypotension.

Postprandial hypotension mostly occurs in the elderly, especially in elderly patients with hypertension, and more attention should be paid to the risk of postprandial hypotension.

　First, what is postprandial hypotension

Postprandial hypotension is a common and unique disease of the elderly, which is mainly manifested as a significant decrease in postprandial blood pressure compared with that before meals. Patients with severe and acute decline may have blackness, syncope, falls, and even cardiovascular and cerebrovascular events. Among the three meals, postprandial hypotension after breakfast is the most common, followed by lunch, and it is less common after dinner. The prevalence of postprandial hypotension is generally 29%-70%, and there are great differences among different elderly people. The incidence of elderly people in ordinary communities is low, and the elderly, hospitalized patients and elderly people with various diseases are high, and individual reports can reach 80%-90%.

Postprandial hypotension is very harmful to the elderly, which may lead to syncope, fall, trauma, stroke, angina pectoris, increased risk of cardiovascular and cerebrovascular diseases and other injuries, and also reduce the quality of life.

　Second, what are the manifestations of postprandial hypotension in the elderly?

Patients with postprandial hypotension may have different clinical manifestations, most of them have no obvious clinical symptoms, ranging from pallor, dizziness, fatigue, drowsiness, chest tightness, nausea, falling and blurred vision to acute cardiovascular events such as stroke, transient amaurosis, angina pectoris and transient ischemic attack.

　Third, which elderly people are prone to postprandial hypotension?

Elderly people suffering from hypertension, diabetes, Parkinson’s disease, autonomic nervous dysfunction, paralysis, multiple system atrophy, Alzheimer’s disease and receiving hemodialysis are prone to postprandial hypotension.

　4. What are the causes of postprandial hypotension in the elderly?

Many factors can lead to postprandial hypotension in the elderly, such as the following:

(1) Age: Whether healthy or not, the elderly are prone to postprandial hypotension. Aging leads to decreased vascular elasticity, impaired vascular endothelial function, decreased cardiac function, impaired sympathetic nerve, decreased baroreceptor sensitivity, and weakened ability to regulate blood pressure, which easily leads to postprandial hypotension in the elderly.

(2) Hypertension in the elderly: The incidence of postprandial hypotension in elderly hypertensive patients has increased significantly, especially in patients with unstable basal blood pressure before meals or patients with high blood pressure before meals. The higher the incidence of postprandial hypotension, the greater the decline. Because long-term hypertension promotes systemic atherosclerosis, it can reduce the sensitivity of baroreceptors in aortic arch and carotid sinus, and can not adjust the decrease of postprandial blood pressure quickly and effectively.

(3) Food: High carbohydrate, large meals and eating hot food lead to the secretion of various hormones in the gastrointestinal tract and pancreas, accelerated gastric emptying, weakened gastric vascular reflex, vasodilation in the gastrointestinal tract and increased visceral blood flow, which leads to a rapid drop in blood pressure and easy to lead to postprandial hypotension.

(4) Body mass index: Patients with low body mass index and emaciation are prone to postprandial hypotension.

(5) Drugs: The elderly are frail and sick, and often take some cardiovascular drugs (such as antihypertensive drugs and diuretics) and anti-Parkinson’s drugs, which can affect the postprandial blood pressure of the elderly.

(6) Smoking: Nicotine, oxygen free radicals, carbon monoxide and other harmful substances in tobacco change the vascular structure, reduce compliance and increase stiffness, thus increasing blood pressure fluctuation. At the same time, smoking aggravates the degree of arteriosclerosis in patients and reduces the sensitivity of baroreceptors in aortic arch and carotid sinus.

(7) Complications with other basic diseases: The elderly often suffer from multiple diseases, such as essential hypertension, diabetes, coronary heart disease and Parkinson’s disease, which will also affect the postprandial blood pressure of the elderly.

　Five, how to diagnose postprandial hypotension

Diagnostic criteria for postprandial hypotension are:

(1) The systolic blood pressure drops more than or equal to 20mmHg within 2 hours of eating.

(2) Preprandial systolic blood pressure is greater than or equal to 100mmHg, while postprandial systolic blood pressure is less than 90mmHg.

(3) Postprandial blood pressure did not reach the above standard, but there were symptoms of postprandial cardiac and cerebral ischemia.

Those who meet one of the above three items and exclude hypotension caused by other reasons (dehydration, autonomic nervous system diseases, drugs, etc.) can be diagnosed.

The lowest postprandial blood pressure usually occurs 35 ~ 60 minutes after meals, and some patients can extend it to 120 minutes.

　Six, the elderly how to intervene in postprandial hypotension?

(1) Non-drug therapy: Drinking proper amount of water or green tea before meals, increasing the frequency of meals, reducing the intake of sugary foods and keeping lying or semi-lying after meals are all measures that can be taken.

(2) At present, drugs are the main treatment for postprandial hypotension in the elderly.

α -glucosidase inhibitors: Acarbose, for example, can reduce the absorption of carbohydrates, reduce the increase of visceral blood flow, and thus reduce the degree of blood pressure decline after meals. Its treatment success rate is 63%, and it is suitable for patients complicated with diabetes and obesity.

Dipeptidyl peptidase 4(DPP-Ⅳ) inhibitors, such as vigliptin, can slow down gastric emptying, increase satiety, reduce postprandial blood sugar and improve postprandial blood pressure drop.

Octreotide: It can inhibit the secretion of gastrointestinal hormones, increase the resistance of viscera and peripheral blood vessels, and relieve the blood pressure reduction of the elderly, hypertensive patients and patients with autonomic nervous dysfunction. However, the cost of octreotide is high and it has some side effects, so its use is limited.

Caffeine: As an antagonist of central adenosine receptor, it can improve the blood pressure drop after meals by preventing splanchnic vasodilation, such as drinking 400 ml of green tea before meals.

Gul gum is a polysaccharide extracted from Gul bean, which can prevent postprandial hypotension by slowing down the absorption of glucose. It is more suitable for patients with type 2 diabetes who need diet control and postprandial hypotension caused by abnormal oral glucose tolerance.

Antihypertensive drugs: Blood reflux can be increased by increasing peripheral vascular resistance, which can alleviate the postprandial blood pressure drop of about 25mmHg.

　Seven, the elderly how to prevent postprandial hypotension.

First of all, we should strengthen the monitoring of blood pressure in the elderly. 24-hour ambulatory blood pressure monitoring can continuously monitor blood pressure all day, and better measure blood pressure level, blood pressure load value, nighttime blood pressure decline rate and morning peak value, blood pressure variability and other indicators. Do it in time and make prevention.

(1) Low-sugar diet: Carbohydrate is the fastest emptying in the stomach, and it has the strongest effect of inducing insulin release, which easily leads to a drop in blood pressure after meals. It is suggested to mix diet, change dietary composition and reduce carbohydrate intake.

(2) Eat less and eat more, and avoid full meals: it can reduce blood transfer to internal organs, thus reducing the extent of blood pressure drop after meals.

(3) Avoid overheated diet: the optimum temperature is 40℃~45℃.

(4) Avoid drinking alcohol during meals: drinking alcohol can cause systemic vasodilation and blood pressure drop.

(5) Drinking water therapy: Drinking about 400 ml of water before meals can effectively reduce the drop of blood pressure after meals, especially for patients with autonomic nervous system dysfunction.

(6) Beware of the adverse reactions of antihypertensive drugs: If the postprandial blood pressure drop of some elderly people is clearly caused by antihypertensive drugs, they should go to the hospital in time to give feedback to the doctor so as to adjust the variety or dosage of antihypertensive drugs.

(7) Post-meal exercise: Mild symptoms can be started at 20-30 minutes after meals, and appropriate exercise should be conducted every 30 minutes, but excessive haste, speed and violence should be avoided. Older people who are not suitable for exercise should be in a rest position.

Therefore, the occurrence of postprandial hypotension in elderly patients with hypertension is closely related to many cardiovascular and cerebrovascular events. Controlling the fluctuation level of patients’ blood pressure is helpful to improve the occurrence of postprandial hypotension, thus reducing the harm to elderly patients.