Extreme weather can pose a threat to heart health, according to researchers.
In an analysis of nearly 2.3 million Europeans, a harmful connection between cold weather and heart disease, particularly in poor areas, was discovered at the ESC Congress 2022. Patients with heart conditions were linked to excessive heart disease and stroke.
Professor Stefan Agewall of the University of Oslo, Norway, reported that climate change is causing an increase in global average temperatures but also extreme cold in some regions. In the summer of 2003, more than 70,000 extra deaths were caused by intense heatwaves. Cold weather is also responsible for excess deaths and hospital admissions.[3,4] Previous research on the cardiovascular effects of heat and cold used individual data, thus increasing our resilience for future weather events.
The population included 2.28 million adults from five cohort studies conducted between 1994 and 2010. The average age ranged from 49.7 years to 71.7 years, and the proportion of women ranged from 36.0% to 54.5%. Data on mortality and new-onset disease were collected through death and disease registers and follow-up surveys.
All participants and subgroups with particular characteristics were examined for the relationships between temperature and cardiovascular conditions and death. A time-straight case-crossover study design was used where for each participant, the scientists compared the temperature on the day of the week that an adverse event occurred (e.g. Monday) with the temperature on the same day of the week without an adverse event (e.g. all remaining Mondays) within the same month.
Cold weather posed an increased risk of cardiovascular disease in general and ischaemic heart disease in particular, as well as a 19% decrease in the likelihood of new-onset ischaemic heart disease (RR 1.22; 95% CI 1.07–1.38).
Professor Agewall noted that the correlations between cold temperatures and deaths were stronger among men and people over the age of 65. The connections between cold and new-onset ischaemic heart disease were stronger among women and people over the age of 65.
Temperature rises from 15°C to 24°C (27°F to 43°F) were associated with 25% (RR 1.25; 95% CI 1.12–1.39) and 30% (RR 1.30; 95% CI 1.10–1.53) increased risk of cardiovascular disease and stroke in people at baseline.
Professor Agewall said: "Clinicians may leverage this information to tailor personalized care to those most at risk of adverse health outcomes on hot and cold days. Patients with heart conditions should stay hydrated in hot weather and follow their doctor's recommendations on medication use. We can all monitor the news for extreme heat and cold alerts and follow local authorities' safety recommendations."
References and notes
Acknowledgments: Dr. Alexandra Schneider from Helmholtz Munich was the primary investigator.
This research was funded by the European Union's Horizon 2020 research and innovation program.