Happy birthday ... maybe.

Mondays, bachelorhood, cold weather, and life on the corporate fast track: Statistical studies have linked them all to an increased risk of heart attack. Biochemist Alan C. Wilson now adds birthdays to this morbid list.

Wilson, of the Robert Wood Johnson Medical School in New Brunswick, N.J., examined the records of more than 100,000 patients for seasonal patterns in heart attack rates. He discovered that rates increased significantly for both men and women in the days immediately preceding and following their birthdays. Excessive partying and emotional stress may underlie this increased risk, suggests Wilson, who reported his findings at last month's meeting of the American College of Cardiology.

The new study reflects a growing scientific interest in the acute risk factors that set off heart attacks. In the past, research into chronic risk factors, such as high blood pressure and cholesterol intake, has received the most funding, Wilson says.

Wilson does not recommend that people behave any differently on their birthdays. His study and others like it seek only to identify possible triggers for sudden heart attacks. "We're trying to identify situations where heart attacks occur and then...work backwards from there [to the underlying causes]," he explains.