There are always hypertensive patients in the clinic who say, “Doctor, why do I get dizzy, weak and palpitated after eating, and my blood pressure is especially low when I measure it!” At this point, the doctor may tell you, “According to the symptoms you reported, you may have postprandial hypotension.” At this point, the patient is even more confused, “I obviously have high blood pressure!” In response to this problem, we have sorted out some scientific knowledge about postprandial hypotension for our friends with hypertension, and we hope it will be of some help to you.
What is postprandial hypotension?
Postprandial hypotension (PPH) refers to the phenomenon of low blood pressure and related symptoms (syncope, coronary events and strokes) caused by the elderly after eating, mainly after breakfast, but also after Chinese food and dinner.
Diagnostic criteria for postprandial hypotension
The diagnosis is made when one of three criteria is met.
1. Systolic blood pressure decreases by 20 mm Hg or more within 2 h after a meal compared with that before the meal;
2.Systolic blood pressure before meal ≥ 100 mm Hg, but after meal < 90 mm Hg;
3.Postprandial blood pressure drop does not reach the above criteria, but postprandial ischemic symptoms (angina, weakness, dizziness, syncope or impaired consciousness) appear.
For elderly people who have postprandial cardiac and cerebral ischemic symptoms, they should be highly alert to the possibility of postprandial hypotension. Generally, the blood pressure before meal and 2 h after meal are measured (every 15-30 min, and the lowest blood pressure value is used as the postprandial blood pressure).
Mechanism of postprandial hypotension
The pathogenesis of PPH is not clear. It is generally believed that the increase in visceral blood flow after a meal leads to insufficient blood perfusion to the heart and brain and other organs. Healthy people can maintain normal postprandial blood pressure through mechanisms such as pressure reflex, sympathetic excitation, and release of vasoactive peptides, but if one or more of these mechanisms are impaired, it may lead to insufficient compensation for PPH.
Factors affecting postprandial hypotension
1, advanced age: as age increases, heart function decreases, vascular compliance decreases, pressure receptor function is down-regulated, and the regulation of blood pressure is weakened.
2, Meals: A diet high in carbohydrates and fat causes postprandial blood pressure to fall more quickly than protein-rich foods, while the degree of decline is greater. Hot foods, colder foods are more likely to cause PPH. blood pressure drops significantly after a large meal than a small meal. Breakfast is most likely to cause PPH, followed by Chinese food.
3, drugs: antihypertensive drugs, diuretics, anti-Parkinson’s disease drugs are likely to cause PPH, and the use of drugs is more likely to cause a drop in blood pressure after a meal.
4, concomitant diseases: frail elderly and patients suffering from hypertension, Parkinson’s disease, diabetes, paralysis, autonomic dysfunction diseases and hemodialysis are more likely to have a drop in blood pressure after meals.
What to do if postprandial hypotension occurs
If postprandial hypotension occurs, lie down for 0.5-2 hours to ensure the blood supply to the brain, heart and other important organs. After the symptoms disappear or the blood pressure returns to normal, you should slowly sit up and stand and walk without dizziness and other symptoms to avoid fractures or other traumatic injuries caused by inadvertent falls.
Treatment of postprandial hypotension
The treatment principle of PPH is to first try to improve the underlying disease, and correct the possible causes as soon as possible, prevention is the main focus, treatment includes non-pharmacological treatment and drug treatment.
1.Non-pharmacological treatment.
(1) Diet: reduce the intake of carbohydrates, small and frequent meals, avoid overheating of diet;
(2) drinking water before meals: healthy people can drink water to increase blood pressure and slow down the heart rate, which may be related to the gastric expansion of vascular sympathetic excitation, cardiac vagal nerve activity increased, has shown that drinking 350-480 ml of water before meals can make autonomic damage to patients with postprandial blood pressure drop by 20 mm Hg, but the method is used with caution in patients with cardiac insufficiency;
(3) Postprandial posture: appropriate postprandial walking can increase heart rate and cardiac output and help maintain normal blood pressure, but excessive exercise should be avoided. In combination with postural hypotension, it is recommended to lie down for half an hour after meals;
(4) Remove the trigger: reduce the dosage of antihypertensive drugs appropriately, such as short- and medium-acting preparations, the original pre- or post-meal medication should be changed to medication between meals, try to use long-acting preparations, and avoid the application of diuretics. Anti-Parkinson’s disease drugs themselves have antihypertensive effects, and should be used to strengthen monitoring and weigh the pros and cons. Strengthen the treatment of underlying diseases, such as hypertension patients get effective control is conducive to improve PPH, in addition, alcohol should be prohibited and fasting during hemodialysis.
2. Drug therapy: including drugs that reduce visceral blood flow, inhibit glucose absorption, and increase peripheral vascular resistance.
For middle-aged and elderly patients prone to postprandial hypotension, especially those with a combination of multiple risk factors, such as hypertension, diabetes, atherosclerosis, etc., be especially alert to the occurrence of cardiac and cerebral ischemic events and seek medical attention in a timely manner!