Cold weather increases risk of heart attack

Heart disease is the leading cause of death in the United States, and is most commonly caused by plaque buildup in the arteries. This constricts blood flow, which leads to heart attack, heart failure, or stroke. Now, a new 16-year study from Lund University set out to examine how weather could have a possible triggering effect for heart attacks. The research found a direct correlation between cold weather conditions and an increase in heart attacks.

The study gathered data from 280,000 patients who were treated for heart attacks and matched the corresponding weather conditions from meteorological records.

Between the 1998 and 2013, the Swedish Myocardial Infarction Registry recorded 280,873 heart attacks treated at a coronary care unit. The study compared these incidences with the weather conditions at the time and grouped together the heart attacks that occurred in similar weather conditions and temperatures.

The results showed that cooler temperatures triggered a higher rate of heart attacks, but the number of heart attacks decreased in warmer temperatures. Researchers found that when the average temperature was below 0 degrees Celsius, there were 4 or more heart attacks per day.

“Our results consistently showed a higher occurrence of heart attacks in sub-zero temperatures. The findings were the same across a large range of patient subgroups, and at national as well as regional levels, suggesting that air temperature is a trigger for heart attack,” said Dr. Moman A. Mohammad from the Department of Cardiology at Lund University, first author of the study.

A possible explanation for this swell in heart attacks could be because blood vessels constrict in colder temperatures, which increases blood pressure.

Because this was an observational study, other outlying factors may have also had an impact on the increased number of heart attacks.

Even so, the study shows that colder temperatures are a possible trigger for heart attacks, so people at risk of cardiovascular disease and heart problems should take extra precaution during the winter months.

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By Kay Vandette, Earth.com Staff Writer