The sudden drop in temperature may be too much for your cardiovascular system! How to enter autumn smoothly?

Currently, high blood pressure has become the number one risk factor for cardiovascular disease in the Chinese people, and has become one of the important causes of death worldwide. In my country, up to 50% of patients with cardiovascular disease, chronic kidney disease, and diabetes die from hypertension, and more than 10 million new cases of hypertension are reported every year. Currently, the number of patients with hypertension nationwide has reached 300 million. Among them, the impact of weather and temperature changes on patients with hypertension is often underestimated.

Patients with coronary heart disease are most affected by cold.

Humans are endothermic animals. Its core temperature (referring to the temperature of major organs such as the heart, brain, lungs, etc.) usually fluctuates within a narrow range centered on 37°C. In extreme cases, it can fluctuate upward by 3°C to 40.5°C, and downward by only -1°C. ℃ reaches 36℃. Beyond this range, life activities will be impaired or even life-threatening.

Exposure to extreme temperatures can induce significant changes in blood pressure, blood viscosity, cholesterol and heart rate. As the incidence of related diseases such as obesity and diabetes increases, the number of people vulnerable to extreme temperatures continues to increase, increasing the future burden of disease.

Harbin, located at 45 degrees north latitude, is frozen for 5 months of the year, and the lowest temperature in winter is often -37℃~-38℃. When the temperature drops below -19°C every winter, the city's death toll increases significantly as the temperature drops. 2.7% of the population's deaths can be attributed to low temperature and cold. In particular, patients with coronary heart disease are hardest hit by low temperature and cold.

The large temperature difference between day and night increases cardiovascular events

my country has a wide north-south latitude and a large span of east-west longitude, making the climate complex and diverse. Due to their high latitude, the cold areas in the north can only withstand the oblique rays of the sun. In addition, the daylight hours are short, which results in a huge temperature difference between the north and the south. At the same time, the northern cold areas are susceptible to winter monsoons and cold waves from the northwest, as well as sudden rainfall and snowfall, which often lead to extreme situations of sudden temperature drops. When the temperature difference between day and night exceeds 9.6°C, the incidence of acute events caused by coronary syndrome and chronic obstructive pneumonia increases significantly.

Follow-up results show that there is a negative correlation between blood pressure and ambient temperature. Canadian doctors have observed that snowfall amount and snowfall time are closely related to the hospitalization rate and mortality rate of patients with myocardial infarction, and this relationship is most obvious on the day after snowfall. Two to three days of continuous snowfall will further increase myocardial infarction. possible. Korean scholars analyzed the impact of day and night temperature range on hospitalization rates for cardiovascular and respiratory diseases and found that for every 1°C increase in the temperature difference between day and night, the hospitalization rates for heart failure and asthma patients increased by 3% and 1.1% respectively. Among them, the elderly were the most Easily implicated.

Some studies have found that the incidence of cerebral hemorrhage shows obvious seasonality, whether male or female, old or young, with the highest incidence of hemorrhagic stroke in winter, followed by autumn and winter. Spring and summer are the lowest. Since the human body's temperature regulation system has limited ability to handle emergencies, sudden temperature changes will bring about corresponding changes in the human body. For example, blood cholesterol, heart rate, and platelet viscosity will increase, and the body's immunity will decrease. Therefore, large temperature changes within a day can cause Excess deaths occur in the population.

"Migrant bird" migration can also affect blood pressure

A chronic disease study analyzed data from 10 regions in my country. The blood pressure levels of residents in these 10 regions generally showed seasonal changes. regularity, but seasonal differences in systolic blood pressure still vary in different regions. For example, the average systolic blood pressure of residents in Zhejiang Province differs by 16 mmHg in winter and summer, the average systolic blood pressure of residents in Haikou City differs by 4 mmHg in winter and summer, and the average systolic blood pressure of residents in Harbin City differs by 7 mmHg in winter and summer. The reason why the systolic blood pressure levels of Harbin residents are not much different in winter and summer may be because there is central heating in winter, so the indoor temperature in winter is very different from that in summer.

A study from 15 cities, including data on 1.9361 million cardiovascular disease deaths, showed that 17.1% of cardiovascular disease deaths in my country were attributed to temperature and climate, of which 15.8% were due to Among deaths caused by cold, 1.3% were caused by heat.

Nowadays, with the convenience of transportation, economic affluence and people’s increasing concept of health care, more and more middle-aged and elderly people are becoming keen on the life of "migratory birds". They leave the harsh north in winter and flock to They form groups to Hainan, Yunnan and other places to escape the cold, and then "return north" in spring and summer. As everyone knows, during a journey from south to north, you will cross two or more different climate zones within a few hours, and the temperature difference between the two places can reach 25°C to 55°C. This "roller coaster" sudden temperature change can easily cause physical discomfort, fluctuations in blood pressure and sudden onset of cardiovascular and cerebrovascular diseases.

When drawing the relationship curve between cardiovascular disease and temperature (U-shaped, V-shaped, J-shaped), some scholars found that when the temperature of the "U-shaped" curve is lower than the cold temperature threshold and higher than the hot temperature threshold, At this time, the mortality rate from cardiovascular disease will “risen all boats”. Unlike cold, which can directly lead to death of cardiovascular patients, cold only plays an indirect role. Epidemiological surveys show that temperature fluctuations have a greater impact on the incidence and mortality of cerebral infarction than the temperature itself. Temperature changes cause changes in blood pressure, which decrease as temperature increases.

Experiments show that when the outdoor temperature is >10°C, for every 1°C increase in temperature, systolic blood pressure and diastolic blood pressure will decrease by 0.4 mm Hg and 0.28 mm Hg respectively. Once the body temperature suddenly rises due to "heat stress", it can cause The blood flow speed of the middle cerebral artery slows down by 30%, which can easily lead to the risk of cerebral infarction.

How to deal with blood pressure changes caused by temperature changes?

It is recommended that middle-aged and elderly people who plan to travel from temperate or cold zones to tropical areas for living and leisure travel in autumn and winter

need to undergo a comprehensive physical examination before departure< /p>

Those with cerebral vascular occlusion or severe stenosis

should follow the doctor’s instructions