Be aware of seasonal changes in blood pressure

Seasonal changes in blood pressure are common clinical phenomena, usually manifested as "high in autumn and winter, low in spring and summer". Similar fluctuations may also occur in travelers from cold to hot areas or in the opposite direction. For the general population, seasonal changes in blood pressure do not cause pathological damage and do not require treatment. However, for some hypertensive patients, seasonal changes in blood pressure may have important clinical significance.

1. Reasons for seasonal changes in blood pressure

Seasonal changes in blood pressure are easily affected by the external environment (temperature, sound, light, air pressure, humidity, etc.) as well as emotions and daily routines. Among them, the impact of temperature changes on blood pressure needs to be paid special attention to.

2. The impact of seasonal changes on blood pressure

Normally, blood pressure in winter is significantly higher than that in summer. Studies have shown that when the outdoor temperature is >5°C, the systolic blood pressure increases by an average of 6.2 mmHg for every 10°C drop in temperature. Seasonal changes also have a significant impact on the circadian rhythm characteristics of blood pressure. Compared with summer, blood pressure drops more at night in winter, and the proportion of dipper or deep dipper blood pressure rhythms is higher. Abnormal circadian rhythm of blood pressure is closely related to the risk of damage to target organs such as the heart, brain, and kidneys, and the correlation may be independent of blood pressure levels.

3. Relationship between seasonal changes in blood pressure and cardiovascular prognosis Many studies have shown that the increase in cardiovascular events in cold seasons is closely related to blood pressure fluctuations, and the most likely mechanism is related to the increased activity of the renin-angiotensin system and the sympathetic nervous system in winter. The results of a large sample study in China showed that cardiovascular disease mortality varies with the seasons, with a 41% increase in risk in winter compared to summer, but the use of heating facilities in the home environment and reduced exposure to cold environments can reduce blood pressure fluctuations and reduce the risk of cold-related cardiovascular disease deaths.

4. Populations susceptible to seasonal changes in blood pressure, leading to adverse cardiovascular outcomes

Elderly hypertensive patients, hypertensive patients with chronic kidney disease and diabetes are more susceptible to seasonal changes in blood pressure, leading to more adverse cardiovascular prognoses, because these patients usually have pathological conditions such as endothelial dysfunction and poor blood pressure regulation, and are more sensitive to seasonal temperature changes.

5. Consider the abnormal fluctuations in blood pressure caused by seasonal changes

The following factors should be excluded when considering seasonal fluctuations in blood pressure: ① use of other drugs that lower or increase blood pressure; ② concurrent infection; ③ dehydration; ④ weight loss; ⑤ frequent and heavy drinking; ⑥ a significant decrease in salt intake leading to a drop in blood pressure; ⑦ poor treatment compliance; ⑧ exclusion of blood pressure changes caused by other diseases.

VI. Management of seasonal changes in blood pressure in hypertensive patients

1. Strengthen home blood pressure monitoring and dynamic blood pressure monitoring to understand the seasonal variation of blood pressure

For patients who are easily affected by seasonal fluctuations in blood pressure or have a history of large seasonal changes in blood pressure, office blood pressure and home blood pressure monitoring should be strengthened when the seasons change, and 24-hour dynamic blood pressure monitoring should be performed at the same time to observe the seasonal changes in blood pressure with external temperature. When there are significant changes in blood pressure, a doctor should be consulted in a timely manner.

2. Flexibly adjust the blood pressure reduction plan to ensure that blood pressure meets the target throughout the entire process

Patients with significantly elevated blood pressure in winter and too low blood pressure in summer should go to the hospital for treatment in a timely manner. After excluding other causes, the doctor will determine that it is abnormal blood pressure fluctuations caused by seasonal changes. The type and dosage of antihypertensive drugs will be adjusted in a timely and flexible manner according to the patient's condition, and long-acting antihypertensive drugs should be selected as much as possible.

3. Intervene in advance when the seasons change to avoid excessive seasonal variation in blood pressure

It is recommended that patients who have difficulty lowering blood pressure in the winter and whose blood pressure is not up to standard, or who have low blood pressure, blackouts or dizziness, or blood pressure-related adverse renal events in the summer, consider adjusting the dosage and type of medication early before the onset of winter and summer after excluding other causes.

4. Pay attention to the impact of the "migratory bird" lifestyle on blood pressure variation

When residents in northern my country go to the south for the winter or to the north for the summer, their blood pressure may fluctuate significantly due to significant changes in ambient temperature in a short period of time, and may even induce adverse cardiovascular events. Patients with cardiovascular diseases, especially elderly patients, should pay attention to increasing blood pressure measurements in the weeks before and after long-distance travel to keep abreast of changes in blood pressure. If blood pressure fluctuates significantly, the intensity of antihypertensive treatment should be adjusted in a timely manner to avoid increasing the risk of adverse cardiovascular events due to changes in ambient temperature, humidity and other meteorological conditions.

Recommended Experts

Guo Linlin, deputy director of the First Department of Cardiology (in charge of work) and deputy director of the Cardiac Rehabilitation Department (in charge of work) of the Affiliated Cardiovascular Hospital of Qingdao University, doctor of medicine, associate chief physician, studied cardiac rehabilitation at the Shenzhen Hospital of the Fuwai Hospital of the Chinese Academy of Medical Sciences, and presided over a project of the Shandong Provincial Department of Education and a project of Traditional Chinese Medicine of Shandong Province. She is an expert member of the Science Popularization and Health Education Working Committee of the Chinese Medical Education Association, a member of the Primary Care and Home Committee of the Chinese Heart Alliance, a member of the Cardiac Rehabilitation Physician Branch of the Shandong Medical Association, a standing member of the Shandong Alliance of the Chinese Heart Alliance, and a deputy director of the Cardiac Rehabilitation Committee of the Qingdao Geriatrics Association