Daylight savings tied to bump in heart attack rates
Setting the clock ahead for daylight savings time may set the scene for a small increase in heart attacks the next day, according to a US study - which suggests that sleep deprivation may be to blame.
Researchers at two hospitals in the US state of Michigan, whose findings appeared in the American Journal of Cardiology, reviewed six years of records and found that they treated an average of 23 heart attacks on the Sunday when the United States switched to daylight savings time.
That compared to 13 on a typical Sunday.
"Nowadays, people are looking for how they can reduce their risk of heart disease and other ailments," said Monica Jiddou, the study's lead author and a cardiologist at William Beaumont Hospital in Royal Oak.
"Sleep is something we can potentially control.
There are plenty of studies that show sleep can affect a person's health.
" A 2008 Swedish report, for instance, found that the chance of a heart attack increased in the first three weekdays after the switch to daylight savings time, and decreased the Monday after the clocks returned to standard time in the autumn.
Jiddou told Reuters Health that her team wanted to see if their respective hospitals experienced the same increase and decrease in heart attacks seen in the Swedish study.
For the new study, she and her colleagues reviewed records for the 328 patients who were diagnosed with a heart attack during the week after a time change between 2006 and 2012, and for the 607 heart attack patients who were treated two weeks before and after the time shifts.
They found that except for the small increase on the Sunday that daylight savings time kicked in, there were no significant differences in heart attack rates in the first week after the spring clock change or in the fall, when people set clocks back.