Toronto (Reuters): A Canadian study claimed that major snowstorm and heavy snowfall may increase the risk of fatal heart attack in men.

The study found, men were 16 percent more likely to have a heart attack and 34 percent more likely to die from a heart attack after a storm dropped at least 20 centimeters (about 8 inches) of snow, compared with periods without any snow. However, women didn’t appear to have an increased risk of heart attack after a major snowfall.

The current study offers fresh insight into this connection by examining several decades of health data for individual patients hospitalized in Quebec, while previous studies have linked snow shoveling to an increased risk of heart attacks in the days following major storms.

The lead study author Dr. Nathalie Auger of the University of Montreal said, “We found that both the quantity and duration of snowfall were associated with an increased risk of heart attack for men but not women.”

He also stated that it’s not clear from the results why researchers only found an elevated risk for men. But according to the results, the author suggested that people should be more cautious when shoveling and avoid it whenever possible, especially if they have a history of heart problems.

Auger added by email “It may be that men shovel more than women, particularly after heavy snowfalls. It is also possible that men put more effort into shoveling, and have a tendency to overdo it.”

The researchers examined data on 128,073 hospital admissions and 68,155 deaths from heart attacks in Quebec between 1981 and 2014 to explore the connections between winter weather and heart attacks.

They focused only on heart attack hospitalizations and deaths from November to April, the months when snowstorms typically hit, and obtained detailed weather data including the amount of snow and duration of storms.

The researchers report in CMAJ that overall, men accounted for 62 percent of the hospital admissions and 57 percent of deaths.

One-third of heart attacks happened the day following snowfall, and about 10 percent happened after at least 5 centimeters (2 inches) hit the ground.

The duration of storms also mattered.

According to the study findings, when snowfall continued for at least 24 hours, men were 8 percent more likely to be hospitalized for a heart attack and 12 percent more likely to die than when it didn’t snow. However, this didn’t happen for women.

Limitations of the study include the lack of data on whether people did in fact shovel snow, or how hard they worked if they did, the authors note. People might not exert themselves as much removing snow with a snow blower as they would shoveling it by hand, the researchers point out.

Dr. David Alter of the University of Toronto said, “We really don't know for certain whether snow shoveling was the only explanation for their results.”