Spring daylight saving time may cause an increased risk of heart attacks

March 11, 2016 by Adam Pope

Many people may groan about losing an hour of sleep March 13, but there may be a more serious reason to be mindful of daylight saving time.

Martin Young, Ph.D.,in the University of Alabama at Birmingham Division of Cardiovascular Disease says that springing forward one hour may lead to an increased risk of heart attacks for people with a history of heart disease.

"Moving the clocks ahead one hour in March is associated with a 10-24 percent increase in the risk of having a heart attack the following Monday and to some degree Tuesday," Young said.

Young says every cell in the human body has an internal time mechanism, also known as a circadian clock, which is responsible for driving rhythms in biological processes. These rhythms follow a roughly 24-hour cycle, responding to changes in light and darkness in an organism's environment. Young says when these clocks are interrupted or experience a sudden change, there can be a number of different health effects.

"Going from a sleeping state to waking is already a stressful event in the body," he said. "When we have an abrupt change, like losing an hour of sleep with daylight saving time, our internal clocks don't have enough time to prepare our organs."

Young says there are many factors that may contribute to increased risk of heart attacks when internal clocks become out of synch with the environment. These include sleep deprivation, inflammation and sympathetic tone.

Sleep deprivation

Individuals who are sleep-deprived generally weigh more and are at an increased risk of developing diabetes and heart disease. Sleep deprivation also can alter other body processes, including inflammatory response, which may contribute to . A person's reaction to sleep deprivation and the time change also depends on whether he or she is a morning person or night owl. Night owls have a much more difficult time with springing forward.

Immune function

Immune cells also have a clock, and normal immune responses depend greatly on the time of day. A time shift like daylight saving puts the body in a pro-inflammatory state, which can worsen outcome.

Sympathetic tone

When a person normally wakes up in the morning, the body sends a large number of electrical signals to the heart, called sympathetic tone. Conversely, sympathetic tone decreases during sleep. However, when someone is sleep-deprived, sympathetic tone can be elevated even when asleep, which is strongly correlated with . "Sleep period is one time the heart should not be challenged," Young said.

Young also says changing time zones and jet lag can cause circadian desynchrony, and increase the risk of heart attacks. It is important to note that these circadian disruptions will increase risk of a primarily in susceptible individuals, who often have underlying diseases.

So, what to do?

"The question then becomes, 'How do you reset your internal clock?'" Young said.

He says different organs in the body have different ways of resetting their own clocks. For example, the brain resets according to light exposure, while the liver resets according to when the body receives nourishment from food. However, some organs, such as the heart, receive mixed signals, thereby leading to confusion and dysfunction.

Young says likely doesn't impact just the heart, since all cells in the body possess . Researchers like David and Jennifer Pollock, Ph.D., are studying the effects of clocks on blood pressure, while Shannon Bailey, Ph.D., is studying their effects on the liver.

So before you set your clock forward one hour, what should you do to prepare your body to a new schedule?

Young suggests easing the transition, by dividing up the one-hour loss over the course of the weekend. For example, if you usually wake up at 6 a.m. on a weekday, then set your alarm for 5:40 a.m. Saturday, 6:20 a.m. (new ) Sunday, and 6 a.m. Monday. In addition, eat a decent-sized breakfast, then go outside in the sunlight and exercise (as appropriate and as recommended by your doctor).

"Doing all of this will help reset the central, or master, clock in the brain that reacts to changes in light/dark cycles, and the peripheral clocks—the ones everywhere else, including the one in the —that react to food intake and physical activity," Young said. "This will enable your to naturally synch with the change in the environment, which may lessen your chance of adverse health issues Monday."

Explore further: Losing hour over weekend may put heart at risk Monday

Related Stories

Losing hour over weekend may put heart at risk Monday

March 8, 2012
(HealthDay) -- Not only do you lose an hour of sleep after the clocks move ahead to daylight saving time this weekend, you may also be at increased risk for a heart attack, an expert warns.

Adjusting your body clock when the time changes

November 4, 2014
As we reset our clocks and watches for daylight saving time, it's a good opportunity to think about our body clocks as well. Our bodies naturally operate on 24-hour cycles, called circadian rhythms, that respond to external ...

Always sleepy after the change to daylight saving time?

March 8, 2015
(HealthDay)—You lost an hour's sleep overnight Saturday when the clocks moved ahead. But there are a number of things you can do to cope with the switch to daylight saving time, a sleep expert says.

Daylight saving time tied to brief spike in stroke risk

February 29, 2016
(HealthDay)—Changing the clocks for daylight saving time may cause a short-lived spike in some people's risk of suffering a stroke, a preliminary study hints.

Switch to Daylight Saving Time doesn't have to cost you sleep

March 10, 2016
With Daylight Saving Time coming up this weekend, Dr. Alon Avidan, director of the UCLA Sleep Disorders Center, has some suggestions for staff and faculty on the best ways to adjust to the time change as we "spring forward" ...

Sleep specialist says begin preparing now for this weekend's change to daylight saving time

March 4, 2015
When daylight saving time takes effect on Sunday, March 8, it doesn't have to mean a miserably groggy Monday morning. Start planning now to ease your body into the time transition.

Recommended for you

Breathing dirty air may harm kidneys, study finds

September 21, 2017
Outdoor air pollution has long been linked to major health conditions such as heart disease, stroke, cancer, asthma and chronic obstructive pulmonary disease. A new study now adds kidney disease to the list, according to ...

Excess dietary manganese promotes staph heart infection

September 21, 2017
Too much dietary manganese—an essential trace mineral found in leafy green vegetables, fruits and nuts—promotes infection of the heart by the bacterium Staphylococcus aureus ("staph").

Frequent blood donations safe for some, but not all

September 21, 2017
(HealthDay)—Some people may safely donate blood as often as every eight weeks—but that may not be a healthy choice for all, a new study suggests.

Higher manganese levels in children correlate with lower IQ scores, study finds

September 21, 2017
A study led by environmental health researchers at the University of Cincinnati (UC) College of Medicine finds that children in East Liverpool, Ohio with higher levels of Manganese (Mn) had lower IQ scores. The research appears ...

Higher levels of fluoride in pregnant woman linked to lower intelligence in their children

September 20, 2017
Fluoride in the urine of pregnant women shows a correlation with lower measures of intelligence in their children, according to University of Toronto researchers who conducted the first study of its kind and size to examine ...

Researchers see popular herbicide affecting health across generations

September 20, 2017
First, the good news. Washington State University researchers have found that a rat exposed to a popular herbicide while in the womb developed no diseases and showed no apparent health effects aside from lower weight.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.