Irregular sleep patterns and shift work linked to organ disease

Apr 8 2008

Disruption of an individual's natural sleep-wake cycle has been determined to be a contributing factor in the development of organ disease.

The findings of U of T researchers were recently published in the Journal of American Physiology.

The human body works according to a natural 24 hour sleep-wake cycle, also referred to as a circadian rhythm, which controls body temperature, sleep/wake timing, and the way our organs and body systems work together. Past research has shown that irregular sleep patterns and shift work take a toll on even the healthiest person over an extended period.

“As researchers, we accept that biological clocks and their rhythms are important for health, but there are virtually no experimental data demonstrating a casual link between circadian dysregulation and organ pathology,” says researcher Martin Ralph, a Professor out of the Department of Psychology at U of T, and one of the lead researchers on the project. “We knew that circadian rhythm disruption had been linked with reduced longevity so we decided to try and find out where, why and how longevity is compromised.”

The team, headed by Dr. Michael Sole, and which included researchers from the Peter Munk Cardiac Centre at the University Health Network and the departments of Psychology and Physiology at the University of Toronto, found that coordination of the many circadian clocks throughout the body is critical for normal healthy organs and that long-term disruption of normal circadian rhythms can ultimately result in heart and kidney disease.