BIRMINGHAM, Ala. (WBRC) – Daylight Saving Time began Sunday, and beyond losing an hour of sleep, health experts warn the time change carries added risks for people with a history of heart disease.
Martin Young, a professor in UAB’s Division of Cardiovascular Disease, said heart attacks increase 10-24% on the Monday and Tuesday following the spring time change. He said multiple factors contribute to that spike, including loss of sleep and the misalignment of the body’s internal clock.
What happens to the body
Every cell in the human body has an internal time mechanism, also known as a circadian clock, responsible for driving rhythms in biological processes on a roughly 24-hour cycle, according to a UAB press release. When those clocks are interrupted or experience a sudden change, several health effects can follow.
“Going from a sleeping state to waking is already a stressful event in the body,” Young 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 reset various biological processes.”
Young said the time change is also associated with an increased risk of accidents, in addition to heart attacks.
Sleep deprivation and heart risk
According to the UAB press release, individuals who are sleep-deprived generally have an increased risk of cardiometabolic diseases, including obesity, diabetes, and heart disease. Sleep deprivation can also alter inflammatory responses and blood clotting, which may contribute to heart attack risk.
“When you have sleep deprivation, you’re going to get changes in your body such as increased clotting and also increased activation of the immune system and all of those things can contribute towards having a heart attack, or myocardial infarction,” Young said.
Young also noted that a person’s response to the time change depends on whether they are a morning person or a night owl, with night owls having a more difficult time adjusting to springing forward, per the UAB press release.
Circadian disruption and clotting
Immune cells also have a clock, and normal immune responses depend on the time of day, according to the UAB press release. A time shift like Daylight Saving Time puts the body in a pro-inflammatory state, which can worsen heart disease outcomes.
“The sleep period is one time when the cardiovascular system should not be challenged,” Young said.
Young explained each organ resets its internal clock differently — the brain uses light cues, while the liver responds to meal timing. The heart receives a mix of those signals, which can create confusion and disrupt normal function, per the UAB press release. Young also said changing time zones and jet lag can cause similar circadian disruption and increase heart attack risk, primarily in individuals with underlying illnesses.
How to ease the transition
Young recommends spreading the one-hour loss across the weekend to reduce the impact. According to the UAB press release, those who normally wake up at 6 a.m. on weekdays should set an alarm for 5:40 a.m. Saturday, 6:20 a.m. Sunday and 6 a.m. Monday. He also recommends eating a substantial breakfast, going outside in sunlight and exercising, as recommended by a doctor.
“Doing all of this will help reset the central 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 heart, that react to food intake and physical activity,” Young said. “This will enable your body to naturally sync with the change in the environment, which may lessen your chance of adverse health issues on Monday.”
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