WASHINGTON — Researchers found a 25% increase in the incidence of MI on the Monday after the spring daylight saving time adjustment compared with other Mondays during the year.
Results also revealed a 21% decrease in the incidence of MI on the Tuesday after fall daylight saving time adjustment compared with other Tuesdays during the year, according to study findings presented at the American College of Cardiology Scientific Sessions.
However, the total number of MIs did not change the week after daylight saving time adjustments, Amneet Sandhu, MD, cardiology fellow at the University of Colorado, Denver, and colleagues found.
The researchers analyzed data from the BMC2 database of nonfederal hospitals in Michigan. Their review yielded 42,060 hospital admissions for acute MI requiring PCI from 2010 to Sept. 15, 2013.
They evaluated change in acute MI incidence in conjunction with shifts in and out of daylight saving time and compared admission rates for MI the week before and the week after daylight saving time change, Sandhu said at a press briefing. They also constructed trend models of all admissions accounting for seasonal variation, random trends, hour lost of daylight saving time and hour gained of daylight saving time.
The researchers found no difference in the total weekly number of PCIs performed in 2010 to 2012 during the spring time changes (week before, 661; week after, 654; P=.87) and fall time changes (week before, 610; week after, 652; P=.25).
However, the RR for MI was higher on the Monday after the spring time change compared with other Mondays (RR=1.24; 95% CI, 1.05-1.46) and lower on the Tuesday after the fall time change compared with other Tuesdays (RR=0.79; 95% CI, 0.62-0.99).
“The importance of this work is if we can identify days or time periods where there are more heart attacks, we can be better prepared to take care of our patients,” Sandhu said. “Second, we need to look further into the relationship between the sleep-wake cycle and circadian rhythms in regards to their effects on cardiovascular health.” – by Erik Swain
For more information:
Sandhu A. Abstract 1117-243. Presented at: American College of Cardiology Scientific Sessions; March 29-31, 2014; Washington, D.C.
Disclosure: Sandhu reports no relevant financial disclosures.