Researchers at the Peter Munk Cardiac Centre of the Toronto General Hospital have found that disrupted sleep rhythms could not only hamper neuropsychological functions, but also lead to serious heart and kidney diseases.

Dr. Michael Sole, Cardiologist and founding director of the Peter Munk Cardiac Centre and Professor of Medicine and Physiology at the University of Toronto, said that this is the first study of its kind to demonstrate that sleep cycle disruption actually causes heart and kidney disease.

“Disrupted circadian rhythms have a devastating effect on the heart, kidney and possibly other organs,” he added.

In the study, Sole and his colleagues found that when internal biological clocks in hamsters are out of sync with external rhythm regulators, the heart becomes damaged and enlarged, and the kidney tubules sustain significant scarring.

The significance of circadian rhythms, the body’s ‘hard-wired’ 24-hour sleep-wake cycle, is well understood in the regulation of cardiovascular physiology.

In previous studies, Sole and his colleagues suggested that renewal of cardiovascular tissues predominantly occur during sleep; therefore sleep interruption can directly damage organs.

Trans-meridian flight crews, truck drivers and shift workers often suffer from sleep cycle disruption because of the nature of their jobs.

The medical focus has largely been on neuropsychological factors such as task performance and memory, but such people are known to have a higher than average prevalence of heart disease.

“Shift workers and flight-crews might want to consider these findings when scheduling work time,” Dr. Sole said.