If you've just had knee, shoulder or hip surgery, circadian rhythms could potentially speed up the healing process. A study conducted by Canada's McGill University shows for the first time that our biological clock is heavily involved in healing after surgery.Anti-inflammatory drugspromote post-operative recovery most effectively when taken during active periods of our internal clock.
Circadian rhythms as the body's own healing agent
So the study recently published in Scientific Reports suggests that anti-inflammatories in the afternoon or at night during the resting periods of the circadian rhythm can significantly influence healing and bone repair after surgery. This is mainly because during these times the cells known as osteoblasts rebuild the bone.
Previous research has shown that circadian rhythms play a role in diseases such as cancer, Alzheimer's, arthritis and Parkinson's. However, this is the first study to examine their influence during surgery or injury. Faleh Tamimi Marino, a Canadian professor of translational craniofacial research, is the senior co-author of the article alongside Belinda Nicolau and Laura Stone. Inflammation after surgery is critical to healing because part of the process involves both destroying any bacteria in the area and signaling to attract the cells that will rebuild the tissue. However, the process is not a constant.
Significant differences in healing rate and genes
The researchers compared pain and bone healing in two different groups of mice with broken tibia. One group was given constant doses of anti-inflammatory agents over a 24-hour period. The team only gave the others antiphogic drugs in the morning, during the active phases of the circadian rhythm, and analgesics at night.
The researchers found that the second group recovered from the pain of the injury. They also regained full bone strength faster than the others. Surprisingly, they also found differences between groups in the expression of over 500 genes. These are specifically related to the healing processes of the bones.
“It’s almost as if morning and evening anti-inflammatories are two different medications,” adds Faleh Tamimi.
The rhythm of the body's own healing
"When I was a child and cut myself, my mother told me, 'Don't worry, go to sleep and you'll feel better tomorrow,'" said Haider El-Waeli, the study's first author. He wrote the paper while working on his doctoral thesis at McGill and is now a clinical resident at Dalhousie University. “It turns out she was right because most of the healing happens at night.”
“The body has its own rhythm,” adds Tamimi. “When you give anti-inflammatories in the morning, you work with the body’s rhythm, and when you give them at night, you work against it, so they interfere with healing.”
In the next step, the researchers will collect preliminary data from aclinical study. In this, they monitor pain and healing associated with wisdom tooth extraction using two different drug treatments. They administer one exclusively anti-inflammatory medication and the other only anti-inflammatory medication in the morning and at lunchtime. In the afternoon and evening they give analgesics. The preliminary results are promising.
