Dying of cold -- more heart attacks in cooler weather

August 10, 2010

Lower outdoor temperatures are linked to an increase in the risk of heart attacks, according to a new study by scientists at the London School of Hygiene & Tropical Medicine (LSHTM).

For the study the researcher, led by Krishnan Bhaskaran of LSHTM found that each 1°C reduction in temperature on a single day is associated with around 200 extra heart attacks.

Bhaskaran and colleagues analysed data on 84,010 patients admitted to hospital with a between 2003 and 2006 and compared this with daily temperatures in England and Wales. The results were adjusted to take into account factors such as air pollution, influenza activity, seasonality and long term trends.

He found that a 1°C reduction in average daily temperature was associated with a cumulative 2% increase in risk of heart attack for 28 days. The highest risk was within two weeks of exposure. The heightened risk may seem small but in the UK there are an estimated 146,000 heart attacks every year, so even a small increase in risk translates to around 200 extra heart attacks for each 1°C reduction in temperature on a single day.

"Older people between the ages of 75 and 84 and those with previous coronary heart disease seemed to be more vulnerable to the effects of temperature reductions," comments Krishnan Bhaskaran, "while people who had been taking aspirin long-term were less vulnerable." He continues, "We found no increased risk of heart attacks during higher temperatures, possibly because the temperature in the UK is rarely very high in global terms. Our results suggest that even in the summer, the risk is increased by temperature reductions." In conclusion, he says "our study shows a convincing short term increase in the risk of myocardial infarction (heart attacks) associated with lower ambient , predominantly in the two weeks after exposure."

He says that further studies need to be conducted to see what measures could be used to avoid the increased risk, such as advising patients, particularly the elderly, to wear suitable clothing and to heat their homes sufficiently.

More information: British Medical Journal bmj.com

Related Stories

Recommended for you

Natural compound reduces signs of aging in healthy mice

October 27, 2016

Much of human health hinges on how well the body manufactures and uses energy. For reasons that remain unclear, cells' ability to produce energy declines with age, prompting scientists to suspect that the steady loss of efficiency ...

A metabolic switch to turn off obesity

October 27, 2016

You've tried all the diets. No matter: you've still regained the weight you lost, even though you ate well and you exercised regularly! This may be due to a particular enzyme in the brain: the alpha/beta hydrolase domain-6 ...

Mitochondria control stem cell fate

October 27, 2016

What happens in intestinal epithelial cells during a chronic illness? Basic research conducted at the Chair of Nutrition and Immunology at the Technical University of Munich (TUM) addressed this question by generating a new ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.