Daylight Savings and Heart Attacks

A team of Swedish researchers conducted a study in 2008 that showed the rate of heart attacks during the first three weekdays following springtime daylight saving time increased by about 5 percent from the average rate during other times of the year. The effect did not arise at the end of daylight saving time in the fall.

The researchers attributed the small surge in heart attacks in the springtime to changes in people's sleep patterns. Lack of sleep can release stress hormones that increase inflammation, which can cause more severe complications in people already at risk of having a heart attack.

The 2009 Journal of Applied Psychology study found that mine workers arrived at work with 40 minutes less sleep and experienced 5.7 percent more workplace injuries in the week directly following the springtime daylight saving transition than during any other days of the year. The researchers attribute the injuries to lack of sleep.

A 2012 Journal of Applied Psychology study found that the incidence of cyberloafing significantly increased in more than 200 metropolitan US regions during the first Monday after daylight saving time in the spring, compared with the Mondays directly before and one week after the transition. The team attributed the shift to a lack of sleep and thus lack of workday motivation and focus.