Exposure to overhead bright bedroom light while sleeping at night is associated with a higher incidence of heart problems regardless of other cardiac-related risk factors, according to a new report.
For the study’s objective, cardiovascular diseases include coronary artery disease, myocardial infarction, heart failure, atrial fibrillation, and stroke.
Monash University researcher Daniel Windred, Harvard University research fellow Angus Burns, and University of Manchester professor Martin Rutter determined that sleeping with bright bedroom lights turned on created a 56 percent greater risk of developing heart failure, a 32 percent higher risk of coronary artery disease, and a 28 percent higher risk of stroke.
“These findings suggest that avoiding exposure to night light may lower risk of cardiovascular diseases,” they said in the report. “Light at night causes circadian disruption, which is a known risk factor for adverse cardiovascular outcomes.”
Neither Windred, Burns, nor Rutter responded to requests for comment by the time of publication.
The study found differences in impact based on age and gender. For example, the brighter night light had a larger-magnitude association with adjusted risk for heart failure in women and younger individuals
Board-certified neurologist Jeremy Liff refers to sleep-disruptive brightness as light pollution and recommends protecting sight while sleeping.
“Light affects the circadian rhythm by entering through our eyes, to the retina, and then to a part of the brain called the suprachiasmatic nucleus so with regards to the issues raised by the study, a sleep mask would be very helpful if you sleep in a place that has a lot of light pollution,” Liff told NTD.
The study further determined that women exposed to bright night light had similar heart failure risks to males exposed to the same amount of bright night light and for risk of coronary artery disease, the size of the association of brighter night light with higher adjusted risk was larger in females than males.
“Hormonal changes, particularly in postmenopausal women, further impact melatonin production, influencing both sleep and breast cancer risk profiles,” physician researcher Dr. Eugene Lipov told NTD.
Overall, however, the extent of brighter night light exposure with the risk for myocardial infarction or stroke did not vary with age or gender, according to the study.
“For shift workers, wear dark sunglasses on the commute home to avoid early-morning light exposure, which makes daytime sleep harder,” Lipov added.
