Emergency visits for stroke are elevated after a heatwave, according to research presented at ESC Asia.
Climate change and global warming are worldwide problems, and stroke is a leading cause of death. A Japanese study shows that older adults maybe more vulnerable to stroke after exposed to hot weather.
Preventative measures such as insulated housing and AC should be considered a public health priority to protect the elderly from stroke.
The study author Dr. Ryohei Fujimoto belonged to Okayama University, Japan. There is little information on the effects of high temperatures on the risk of stroke. So Fujimoto’s & team decided to delve deeper into the topic.
Study into the connection of stroke & hot weather:
This study looked at the association between heat exposure and emergency visits for stroke in older adults.
The study included 3,367 citizens of Okayama, a city in western Japan. Participants were 65 years or older and were taken to emergency hospitals between 2012 and 2019 for the onset of stroke. This was during and several months after the rainy season.
The researchers obtained hourly data on outdoor temperature, relative humidity, barometric pressure, and the average atmospheric concentration of particulate matter less than 2.5 m in diameter (PM2.5) from the Okayama weather station.
The association between temperature and stroke was examined during the rainy season, for 3 months.
A time-stratified case-crossover study design was used where for each participant. The team compared the temperature on the day of the week a stroke occurred with the temperature on the same day of the week with no strokes within the same month.
This avoided the potential confounding effects of individual characteristics, long-term time trends, seasonality, and day of the week.
Heat do increase stroke risk for older people:
The team found that the relationship between temperature and stroke in older folks was strongest one month after the rainy season.
For each 1degree C increase in temperature, there was a 35% greater risk of emergency visits for stroke after adjusting for relative humidity, barometric pressure, and PM2.5 concentration.
When each type of stroke was analyzed separately, each 1degree C increase in temperature was associated with a 24% higher chance of hemorrhagic stroke, a 36% increased risk of ischemic stroke, and a 56% raised risk of transient ischemic attack.
In a second analysis, the team checked whether there was a possible “effect modification” according to the rainy season. For this analysis, the study period was the rainy season. Again, the relationship was strongest one month after the rainy season.
Compared with the study period, there was a 31% higher chance of stroke for each 1. C rise in temperature.
The study suggests that older adults should try to keep cool during hot spells. For example, by staying indoors during peak temperatures. Public health systems can help by providing cool spaces for members of the public during the hottest months of the year.
Parvathy Sukumaran 
