Heart health impacted by sleep disruptions, shift work, study finds

A new study led by the Ontario Veterinary College shows shift work or sleep disorders can lead to heart disease.

Shift-working mice 'developed profound heart disease,' researcher says

A man's head is seen resting on a pillow while a bedside alarm clock reads 12:30 p.m.
The shift-working mice in the study, when left to do their own thing, "developed profound heart disease," Ontario Veterinary College biomedical sciences professor Tami Martino says. (fasphotographic/Shutterstock)

Not getting a good night of sleep could hurt your heart, a new study has found.

A team led by biomedical sciences professor Tami Martino in the Ontario Veterinary College at the University of Guelph found disturbing the body's natural circadian clock, such as through shift work or sleep disorders, can lead to heart disease.

"If you disturb rhythms, that has adverse effects on your heart," Martino said in an interview on CBC K-W's The Morning Edition with host Craig Norris.

"Our shift working mice, just left to do their own thing, over time, developed profound heart disease."

Circadian clocks are found in all of the body's cells. The researchers found disturbing that clock triggers changes in the molecular pathways. Specifically, circadian disruption affects microRNA – small molecules that help to regulate gene expression in the heart.

The study was published Feb. 20 in the Journal of Molecular and Cellular Cardiology.

Morning people or night hawks

Martino said the body never really gets used to shift work or other sleep disruptions, but other researchers are working on ways to mitigate the damage to the heart.

That includes light blocking glasses that help suppress melatonin, a natural hormone that becomes active when you sleep.

As well, some people might just be natural morning people or night hawks.

"There is some thought out there that maybe some people are more genetically predisposed to mornings versus evenings and people tend to self-select for occupations associated with that and they might do a little bit better," she said.

There are also some pharmaceutical options, including a new drug in development for jet lag that will help people maintain sleep, she said.

In the study, drugs designed to control cardiac hypertrophy helped prevent the abnormal cardiac growth in the mice.