- High temperatures place more strain on the heart
- This happens, because to cool the body, the heart pumps blood from the organs to under the skin
- Inherently hot areas of the world like Kuwait and the Arabian Peninsula are experiencing higher temperatures than ever before
Heart disease deaths spike with extreme heat, and rising temperatures due to climate change may lead to a surge in such deaths in hot regions, researchers say.
For the study, the investigators analysed 2010 to 2016 data on more than 15 000 heart-related deaths among people aged 15 and older in Kuwait, which has an average temperature of 28 degrees Celsius (C).
Compared to days when the average temperature was 35 degrees C, the number of heart-related deaths was three times higher on days when the average daily temperature was 43 degrees C.
On those extremely hot days, the death rate was 3.5 times higher among men and 2.5 times higher among women, the findings showed. The death rate among working-age people (aged 15 to 64) was 3.8 times higher; and that among people 65 and older was just over twice as high.
Lead author Barrak Alahmad said men and working-age people may have been at greater risk because they spend more time outdoors.
Global warming not evenly distributed
The study was published on 30 March 30 in the journal Circulation. While it shows an association between extreme heat and heart-related deaths, it does not prove cause and effect, the study authors noted.
"While cardiologists and other medical doctors have rightly focused on traditional risk factors, such as diet, blood pressure and tobacco use, climate change may exacerbate the burden of cardiovascular mortality, especially in very hot regions of the world," said Alahmad, a doctoral candidate in environmental health at the Harvard T.H. Chan School of Public Health in Boston.
When its core temperature rises, the body tries to cool itself by shifting blood from the organs to underneath the skin. This forces the heart to pump more blood, putting it under significantly more stress, the researchers explained.
Alahmad noted that global warming is not evenly distributed. Regions that are inherently hot, like Kuwait and the Arabian Peninsula, are recording higher temperatures than ever before. The world's highest temperature in the past 76 years – 53.88 degrees C – was recorded in Kuwait in 2016.
"We are sounding the alarm that populations in this part of the world could be at higher risk of dying from cardiovascular causes due to heat," Alahmad said in an American Heart Association news release.
Image credit: Jaroslaw Kwoczala, Unsplash