Managing Circadian Rhythms Using Intense Light, Chronological Time May Prevent Heart Disease

Managing circadian rhythms by using intense light and chronologically timed therapy may treat or even prevent a variety of circulatory system conditions, including heart disease, according to a study published in Circulation Research.

“The impact of circadian rhythms on cardiovascular function and disease development is well established,” said Tobias Eckle, MD, PhD, the study’s lead author and a professor of anesthesiology at the University of Colorado School of Medicine, via a press release. “However, translational preclinical studies targeting the heart’s circadian biology are just now emerging and are leading to the development of a novel field of medicine termed circadian medicine.”

Circadian rhythms have a substantial influence on how the cardiovascular system operates. Blood pressure and heart rates follow distinct patterns, peaking during the day and ebbing at night. A disruption in those patterns can lead to worse cardiovascular disease outcomes, including myocardial infarction and heart failure. Moreover, light is critical for maintaining the proper balance and functioning of the body. Shift employees who work night hours and then day hours often have worse cardiac outcomes.

According to investigators, when light hits the human eye, it is transmitted to the suprachiasmatic nucleus, a structure in the brain’s hypothalamus that regulates most circadian rhythms in the body. Intense light stabilizes the PER2 gene and increases levels of adenosine, which blocks electrical signals in the heart that cause irregular rhythms.

Dr. Eckle has used light therapy with patients following surgery and has observed positive changes, including lower levels of troponin, a key protein whose elevation can signal a heart attack or stroke. Given the mounting evidence that intense light and timed drug treatments are effective, Dr. Eckle feels it is time to move forward with more clinical trials.

“Circadian rhythms play a crucial role in cardiovascular health, influencing the timing of onset and severity of cardiovascular events and contributing to the healing process from disease,” Dr. Eckle said. “Studies in humans are clearly required. Regarding intense light therapy, chronotherapy and restricted feeding are low-risk strategies that should be tested sooner rather than later.”