Shedding Light on Link Between Sleep and Sudden Death

Shedding Light on Link Between Sleep and Sudden Death

Researchers at Case Western Reserve have brought light to a subject long shrouded in mystery: Why do the number of sudden deaths surge in the early morning?

Faculty in the School of Medicine say the culprit involves a genetic factor, Kruppel-like Factor 15 (KLF15). It turns out this protein links the body’s natural circadian rhythm to the heart’s electrical activity—and, in turn, helps regulate it.

The research, published earlier this year in Nature, is the first to define a molecular connection between the body’s circadian rhythms—biological changes occurring in about a 24-hour cycle—and heart arrhythmias, including the electrical jolts that cause sudden death.

“The question of why the incidence of sudden death clusters at certain times of day has been a mystery,” says Case Western Reserve cardiovascular researcher Darwin Jeyaraj, MD. “Our study pinpoints KLF15 as a previously unknown mechanism for instability in the heart that seems to play an important role.” The work was carried out in the lab of Mukesh K. Jain, MD, director of the Case Cardiovascular Research Institute, and also involved a multi-institutional team of scientists drawn from around the world.

Sudden cardiac death is the leading cause of death in the U.S., taking the lives of an estimated 700 to 800 people each day.

Following up on their finding that a deficit or excess of KLF15 can disrupt the heart’s electrical cycle, researchers plan to delve further into how the biological clock is tied to the heart’s electrical stability and how it influences sudden deaths—a first step to preventing them. Their purpose is to develop novel prevention and treatment approaches: Lifestyle adjustments such as sleep pattern changes may be identified to lessen risk, Jeyaraj says, and medications may be developed in the future to maintain safe KLF15 levels.