Daylight Savings Time Shift Linked To More Heart Attacks, As If We're Not Already Grumpy Enough About It

Most of us aren't ever too happy with Daylight Savings Time; losing an hour of sleep will do that to you. In fact, Facebook's Data Science blog demonstrated that status updates with the words "tired," "sleepy," and "exhausted" increased after Daylight Savings Time. Now a recent study is giving us even more reason to dislike it: the fall shift in Daylight Savings Time is correlated with increased heart attacks.

The study, which was based on research culled from Michigan hospitals' 2010-2013 data, demonstrated that on average, these hospitals admitted about 32 heart attack patients on Mondays. The number was about 25 percent higher on the Mondays after Daylight Savings started. Additionally, the number of heart attack patients on the Tuesday after Daylight Savings ended (when the clock goes back one hour) dropped by 21 percent.

It would be easy to read the study and leave with the impression that Daylight Savings Time causes heart attacks, but it's not that simple. The number of heart attack patients throughout the rest of the week following the start of Daylight Savings dropped off, and didn't show a notable increment. Additionally, as scientists in the study noted, the data was limited to hospitals in Michigan, and also was only based on heart attack patients who had artery-opening operations.

Still, lead author of the study, Dr. Amneet Sandhu, says that while the study doesn't show causation, it supports many interesting theories — mainly that people already at a risk for heart disease could be disturbed by sudden time changes.

"Perhaps the reason we see more heart attacks on Monday mornings is a combination of factors, including the stress of starting a new work week and inherent changes in our sleep-wake cycle," he told CBS. "With Daylight Saving Time, all of this is compounded by one less hour of sleep."