Wounds Sustained In Daytime Heal 60% Faster Than Those At Night

Wounds that occur during the day heal more quickly than the ones sustained at night, a study has suggested. The researchers found skin cells carry out repairs to cuts and burns more effectively during the day, due to which wounds heal up to 60 percent quicker if they happen at daytime.

The team studied similar level burns sustained at night and during the day. When the data was compared, the team found out night-time burns took an average of 28 days to heal, but day-time burns just took 17 days to heal.

The team from Medical Research Council (MRC) Laboratory of Molecular Biology in Cambridge, UK, examined 118 patients at NHS burns units and were astounded by the difference they saw between the night and day time burns, they said in a release made on journal Science.

The study, published in Science Translational Medicine, explained this effect by the way body clock ticks inside every human cell across a 24-hour cycle. The study concluded there was an average 11-day difference in healing times between people hurt at night and during the day. This was found to be because skin cells called fibroblasts changed their behavior based on the 24-hour pattern of our bodies.

These fibroblasts are the body's first defense to any injury. They are rushed to the area of injury within seconds to try and close the wound and prevent blood loss. This activity during the day was much higher compared to that at night, which means the first response of our body to injury was much slower at night, when we should be sleeping.

“You can see by eye, when the cell is wounded only 8 hours apart from each other, in a different circadian phase, the [daytime] wounded ones take off, and the [nighttime] one drags,” said John O'Neill, who co-led the research.

The researchers said in the study the fibroblasts’ time-varying response is an evolutionary response to our sleep cycles. People are more likely to sustain injuries when awake than when sleeping. Over time, this behavior honed our response to wounds.

The researchers think this study could help improve surgery drastically. Some steroids like cortisol can reset a persons’ body clock and may be helpful in night-time procedures.

Studying a patient’s individual 24-hour circadian rhythms can reveal which part of the cycle the body is in. Armed with this knowledge, surgeries can be scheduled according to the particular person’s biological clock. Everybody's body clock runs on a slightly different pattern or ‘chronotype’. This, when gauged, can provide crucial information regarding speed of healing.

"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," Dr John Blaikley, a clinician scientist at the University of Manchester, said in a report by BBC.

The team hopes it can successfully help surgeons control the outcome of surgery better. O’Neill also emphasized the need for further controlled clinical studies to confirm the effect and understand it in greater detail.