Taking long naps daily is associated with cardiac events among both men and women, according to a recent cross-sectional study.

“We found an increased risk for acute myocardial infarctions and sudden cardiac death among men and women who take regular long midday naps in a non-Mediterranean Western European population of people aged 45-75 years,” according to the authors.

The study appeared in the December 2012 issue of the journal SLEEP.

The study involved the baseline examination of 4,123 participants aged 45-75 years. Overall, 135 of the 4,123 subjects (3.3 percent) either suffered from acute myocardial infarction (81 subjects) or a heart attack or died due to a sudden cardiac death (54 subjects) during follow-up. Regular long nap takers showed considerably higher event ratios than the other nap groups.

A more detailed analysis of nap habits (no naps, irregular naps, regular naps less than 60 minutes, regular naps 60 minutes, regular naps more than 60 minutes) showed that irregular naps, regular naps less than 60 minutes and regular naps of 60 minutes were not associated with the risk of coronary artery disease.

“Future research on midday napping should focus on the association between duration and sleep stages of midday nap and corresponding changes of cardiovascular and humoral (i.e. body fluids) during midday naps and thereafter,” the authors suggest.