American Heart Association meeting report:
DALLAS, Nov. 9 -- People with heart disease may want to pay closer attention to weather reports, especially if below-normal temperatures or extreme atmospheric pressures are in the forecast. A study presented today at the American Heart Association's 71st Scientific Sessions suggests that changes in temperature and atmospheric pressure may be related to an increased risk of heart attack in men. Researchers examined the relationship between weather conditions and heart attacks -- both fatal and nonfatal -- among 250,000 men ages 25 to 64 living in and around Lille, France.
Philippe Amouyel, M.D., Ph.D., professor of epidemiology at Lille University School of Medicine in France, reports that an 18° F (10° C) decrease in the temperature average for a particular date increased the risk of a first heart attack that day by 13 percent.
Amouyel says the study results reflect similar trends in heart attack risk for women, but to a lesser extent because of the much lower risk for heart attack observed in general for women than for men in these age classes.
The French team noted a possible relationship between atmospheric pressure and heart attacks. Extremes of pressure were associated with increased risk of heart attack regardless of whether the change in pressure was higher or lower. This trend is called a "V-shaped" relationship, meaning that if the effects of atmospheric pressure were drawn on a graph, the resulting series of points would form the shape of a "V."
"The description of the effect of atmospheric pressure extremes is new," says Amouyel. "The lowest risk was 1,016 millibars -- the standard atmospheric pressure at sea level," Amouyel says. The millibar is the international unit for measuring atmospheric pressure.
"When atmospheric pressure rose by 10 millibars above sea level [the right side
of the "V"], there was an 11 percent increase of heart attack rates, and when
Contact: Carole Bullock
American Heart Association