Wounds heal more quickly during the day than they do at night, a new study published in Science Translational Medicine reports.
This discovery comes from researchers at the UK’s MRC Laboratory of Molecular Biology, who found that burns sustained at night often take much longer to heal than ones sustained during the day.
In the study, researchers examined 118 patients at NHS burn units. They then recorded what time of day the patients got their burns as well as how long the wounds took to heal. Burns that occurred at night took roughly 11 days longer — 28 compared to 17 — to get better.
Researchers explained this odd difference by looking at fibroblasts, the skin cells that rush to the site of injury to close up wounds. This revealed that the cells change their abilities depending on the time of day. While the sun is out, fibroblasts are primed to react to injury. However, they lose that ability at night.
“It is like the 100 meter,” study co-author John O’Neill, a researcher at the MRC Laboratory of Molecular Biology, told BBC News “The sprinter down on the blocks, poised and ready to go, is always going to beat the guy going from a standing start.”
This finding is important because doctors could use the new information to improve surgery. That is because certain drugs — such as the steroid cortisol — can reset an individual cell’s body clock. As a result, it may help night-time procedures by making the body better at healing.
In addition, as every person’s internal clock runs differently, it may also be beneficial to schedule procedures in time with the patients’ 24-hour “circadian rhythms.”
However, such theories need to be tested before they are put into practice. Researchers plan to continue their research into this topic to see what else it could tell them about health.
“By taking these [circadian factors] into account, not only could novel drug targets be identified, but also the effectiveness of established therapies might be increased through changing what time of day they are given,” added John Blaikley, a clinician scientist at the University of Manchester.