United States: Our body has special “clocks” that help control many parts of our health, like sleep and how we use energy. The most important clock is in the brain and controls when we sleep. But there are also some sort of smaller clocks in other parts of our body for example the liver, muscles, and fat, which can help with metabolism (how we use energy).
When the body’s internal clocks get out of sync with the outside world (like when we stay up late or travel to different time zones), it’s called circadian desynchrony. This can affect our health in many ways.
As reported by the Sciencealert.com, In human lives, circadian desynchrony arises in conditions including shift work and jet lag when the intrinsically driven circadian clocks do not properly align with external zeitgebers from the environment.
Previous laboratory studies on circadian human desynchronies have simulated this shift by a 12-hour phase shift of IE and external rhythms or by inverting environmental and behavioral cycles in a period of one to two days.
The findings established modifications of participants’ metabolic rate, notably, a tendency towards increased Blood Sugar level. However, the impact of such more moderate circadian disruption and such possible recovery remains relatively unknown.
In this regard, the methodology involved using experiment in which men and women were exposed to 5hrs shift in their ecological and psychological profile. This was done by extending the time the participants slept by five hours to cover whatever sleep loss incurred during the first period. Data was collected prior to the five-hour interruption and in the subsequent five days.
All meals were standardized, and participants received them from the research team. The study participants were, on average, about 45 years old and overweight, without any reported medical illnesses. We collected assays on metabolism, melatonin, an index of the brain clock and rated perceived sleepiness and alertness every hour throughout the day.
In the first study, we observed improved evening sleepiness and reduced alertness levels right after the five-hour delay. This was accompanied by shifted patterns of melatonin levels suggesting an alteration in the brain’s circadian rhythm. These changes slowly reamplitude over the course of the subsequent five days but remain below baseline.
Due to such a five-hour delay, many metabolic changes occurred. These were lower twenty-four hours energy expenditure in response to meal intake, delayed gastric emptying after breakfast intake, and variation in blood glucose and fatty acid disposition.
Unlike the sleepiness and brain-clock marker (melatonin), all the metabolic changes were completely restored in the five days after the circadian disruption.