That extra hour we have in bed this weekend is a real hazard, and when we go back to work, for some it will be fatal.
Adjusting our day-night routine by an hour seems minor. We should have enough time to adjust our body clocks before work. After all, Winter Time comes in over a bank holiday weekend.
But our body clocks don’t adjust well, and sleep can be disturbed over time. And for some people it is worse. Tuuli Lahti and her colleagues in Finland found that morning people had more disturbed night-time sleep after the autumn transition (BMC Physiology 2008, 8:3).
And now scientists think that these sleep disruptions can contribute to increased heart problems in the days after the clocks go back.
Imre Janszky first reported this using Swedish records. Although his team did find there was less of a risk in the first working day after the clocks went back, the risk of a heart attack increased in the next four days of the working week, compared to the week before (N Engl J Med 2008 359;18). So if that extra hour in bed is good for us, it is gone by Tuesday, and still there on Friday. Our body clocks take longer than just a few days to adjust to even the seemingly minor change of an hour.
More recent research is trying to determine whether certain groups are particularly affected by time changes. Viktor Čulić examined cardiac patients, and controlled for known triggers such as physical exertion, emotional stress, heavy meals, sexual intercourse and other clinical factors. In the autumn time shift he found an increased risk for women, those working, those not taking beta blockers and the physically inactive. (Chronobiology International 2013 30;5) Inge Kirchberger and her team in Germany found that those who had had a heart attack were at higher risk of getting another in the days after the autumn change (BMC Public Health 2015 15:778)
The evidence is building that short term sleep disturbances lead to a heart attack for certain groups, and that changing the clocks should be seen as a trigger for a heart attack.
You would have to ask why we systematically add an additional risk factor for heart attacks by moving the clocks back every year.