Extreme hot and cold spells threaten heart health

Research presented at the European Society of Cardiology 2022 conference in Barcelona showed an association between very cold weather and heart disease deaths, especially in lower socio-economic neighbourhoods.

Extreme weather both hot and cold can have a profound effect on heart health, a study on almost 2.3m European citizens has found.

Research presented at the European Society of Cardiology 2022 conference in Barcelona showed an association between very cold weather and heart disease deaths, especially in lower socio-economic neighbourhoods.

This is in addition to thousands of excess deaths occurring during extreme heatwaves, researchers said.

The study looked at 2.28m adults from five groups in Italy, Germany, Britain, Norway, and Sweden between 1994 and 2010, with the average age ranging from just under 50 to 72. 

The striking findings showed increased risks of death from cardiovascular disease overall and ischaemic heart disease — narrowed arteries — in particular, as well as an elevated risk of new-onset ischaemic heart disease, associated with cold weather. 

With an approximately 10 degree temperature drop, from 5C to -5C, there was a 19% greater risk of death from cardiovascular disease and a 22% elevated likelihood of death from ischaemic heart disease, the research found, while there was a 4% higher risk of new-onset ischaemic heart disease associated with an approximately 11C temperature drop, from 2C to -9C.

Study author Professor Stefan Agewall of the University of Oslo, Norway said: 

Climate change is leading to a rise in the average global temperature but also extreme cold in some regions. More than 70,000 excess deaths occurred across Europe during the summer of 2003 due to intense heatwaves. 

"Cold weather also accounts for excess deaths and hospital admissions. Previously, studies on the cardiovascular effects of heat and cold mainly used aggregated data, such as daily deaths in a city. The EXHAUSTION project used individual data, enabling us to identify vulnerable subgroups for protective interventions, thereby increasing resilience for future weather events.”

Those in less well-off neighbourhoods, as well as women, were more likely to be affected, the research showed.

Prof Agewall said: “The relationships between cold temperatures and deaths were more pronounced in men and people living in neighbourhoods with a low socioeconomic status. The links between cold and new-onset ischaemic heart disease were stronger among women and people older than 65 years.”

Extreme heat is also shown to have an adverse effect on heart health.

Temperature rises from 15C to 24C were associated with 25% elevated risks of death from cardiovascular disease and stroke respectively, in people with heart disease at baseline.

Professor Agewall said: “Clinicians can use this information to provide tailored advice to those most at risk of adverse health outcomes during hot and cold days. 

"Patients with heart conditions should stay hydrated in hot weather and adhere to advice from their cardiologist on medication use. We can all check the news for extreme heat and cold alerts and follow safety tips from local authorities.”

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