As Ramadan, the holy month for Muslims, is upon us, most people in the Muslim world have shifted their eating and sleeping times. They, of course, eat at night as they cannot do so in the day, but many also sleep during the day and wake up at night.
A new University of Colorado Boulder research study, published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), recently pointed out that staying awake all night and sleeping all day for just a few days can disrupt levels and time-of-day patterns of more than 100 proteins in the blood, including those that influence blood sugar, energy metabolism, and immune function.
According to co-author Kenneth Wright, the director of the Sleep and Chronobiology Laboratory and professor in the Department of Integrative Physiology, “this tells us that when we experience things like jet lag or a couple of nights of shift work, we very rapidly alter our normal physiology in a way that if sustained can be detrimental to our health.” The study is the first of its kind to examine how protein levels in human blood, also known as plasma proteome, vary over a 24-hour period and how altered sleep and meal timing affects them.
The paper also determined 30 distinct proteins that vary depending on what internal time of day it is, regardless of sleep and meal timing, and the findings could open the door for developing new treatments for night shift workers, who make up about 20% of the global workforce and are at higher risk for diabetes and cancer. As the results show, the study could also enable doctors to precisely time administration of drugs, vaccines, and diagnostic tests around the circadian clock.
“If we know the proteins that the clock regulates, we can adjust timing of treatments to be in line with those proteins,” said lead author Christopher Depner, a postdoctoral researcher in the Department of Integrative Physiology.
During the study, the researchers recruited six healthy male subjects in their 20s to spend six days at CU’s clinical translational research center, where their meals, sleep, activity, and light exposure were tightly controlled. According to the paper, in the two first days, the men stuck to a normal schedule. Then they were gradually transitioned to a simulated night shift work pattern, in which they had eight-hour sleep opportunities during the day and stayed up all night, eating then.
The researchers drew blood every four hours and used technology which was recently developed by Boulder-based SomaLogic, Inc to assess levels and time-of-day-patterns of 1,129 proteins. They found 129 proteins with patterns that were thrown off by the simulated night shift. Depner explained that by the second day of the misalignment, the team of researchers was already starting to see proteins that normally peak during the day peaking at night and vice versa.
He added that one of those proteins was glucagon, which prompts the liver to push more sugar into the bloodstream. When subjects stayed awake at night, levels not only surged at night instead of day but also peaked at higher levels. Long-term, this pattern could help explain why night shift workers tend to have higher diabetes rates, Depner said.