Daylight Time Linked to Heart Attacks

A study of 42,000 hospital admissions in Michigan has concluded that Daylight Saving Time is responsible for 25% more heart attacks than usual. The impact of moving the clock forward and backward was seen in a comparison of hospital admissions from a database of non-federal Michigan hospitals. It examined admissions before the start of Daylight Saving Time and the Monday immediately after for four consecutive years. An average of 32 patients had heart attacks on any given Monday, but on the Monday immediately after springing the clock forward, there were an average of eight additional heart attacks. Later in the year when standard time returned, heart attack risk fell 21 percent on the Tuesday after the clock was returned to standard time, and people got an extra hour's sleep. The main conclusion of the study suggests that sudden, even small changes in sleep, seem to have detrimental effects.