Cold weather ups heart attack risk--study

Each 1 degree centigrade (1.8 degrees Fahrenheit) reduction in temperature is linked to about 200 extra heart attacks across the UK, researchers say.

While aspirin seems to confer protective benefits against heart attacks, people aged between 75 and 84 and those with a previous history of heart disease are most susceptible to the effects of dropping temperatures.

Details of the study
Researchers at the London School of Hygiene and Tropical Medicine analyzed medical records of 84,010 patients who suffered heart attack between 2003 and 2006.

Using meteorological graphs complied by the British Atmospheric Data Centre, the researchers picked up corresponding daily temperatures for 15 areas in England and Wales.

The researchers also picked up other potential explanatory factors, such as air pollution, flu rates and seasonal patterns, associated with raised heart attack risk.

The heart risk associated with cold conditions was not significant, but it came across as the most prominent factor.

Dropping temperatures are believed to increase the blood pressure and blood clotting risk, both impairing effective heart functioning.

"We can't prove that the cold causes the increases in heart attacks but even after controlling for those other factors we found that they still did not explain the link and therefore we were left with cold," study’s lead researcher, Krishnan Bhaskaran, said.

The researchers found that each 1 degree fall in the daily temperature was linked with a cumulative 2 percent increase in the risk of heart attacks for the next 28 days, translating to about 200 more heart attacks.

Besides adopting the well touted preventive measures like quitting smoke, weight watch and regular exercise, people vulnerable to heart ailments should wrap them up warm, wear a hat to minimize body heat loss through the head and avoid sudden exertion, such as clearing snow or pushing a car, researchers recommend.

But the highest risk came within two weeks of exposure, Bhaskaran pointed.

However, patients taking aspirin regularly had a reduced risk of a heart attack, researchers found.

Preventive measures
"Clinicians should be aware that exposure to environmental heat and cold is a risk factor for cardiovascular disease and should consider this in risk prevention and management," Paola Michelozzi and Manuela De Sario, epidemiologists at the Lazio Region Department of Epidemiology in Rome, said.

Besides adopting the well touted preventive measures like quitting smoke, weight watch and regular exercise, people vulnerable to heart ailments should wrap them up warm, wear a hat to minimize body heat loss through the head and avoid sudden exertion, such as clearing snow or pushing a car, researchers recommend.

The findings of the study feature in the 'British Medical Journal.'