Consequences of Circadian Misalignment

Sleep plays a vital role in the wellbeing of an individual. Sometimes it is not always possible to get a full night’s sleep because something may come up that alters your sleep cycle such as working a night shift, partying on the weekends, or even pulling an all-nighter to cram for an exam. Though these things may seem insignificant because they don’t happen every day, in the long run, a series of inconsistent sleep cycles can have a lasting effect on your health. But just how important is a steady and consistent circadian rhythm to a person?

During Dr. Cavanaugh’s talk on “Using fruit flies to understand the consequences of circadian disruption” at Loyola University Chicago, he focused on circadian misalignment which can be induced by things such as jetlag, shiftwork or irregular schedules, and explained how circadian misalignment has also been linked to many diseases. Dr. Cavanaugh emphasized how it can have a 30-50% increase of risk of injury or illness, increased risk of cancer, pregnancy complications, gastrointestinal disorders, cardiovascular disease, increase in diabetes and obesity, and so on. Dr. Cavanaugh conducted his study centered around fruit flies and how circadian misalignment can reduce lifespan. The purpose of the fruit flies was to track their sleep/wake cycles when their cycle has been altered. The biological clocks of the fruit flies were altered through disruptions in the normal “day time” and “night time” 24-hour cycle and the life span of both the fruit flies whose circadian rhythm was altered, and fruit flies whose circadian rhythm was not, was tracked. Through Dr. Cavanaugh’s research, he found that circadian misalignment actually does decrease the life span of fruit flies.

The New York Times article by Richard A. Friedman, “Yes, Your Sleep Schedule Is Making You Sick”, touches on the drawbacks of sleep deprivation, specifically psychological ones. This article also focuses on a similar idea that Dr. Cavanaugh also included in his talk at Loyola, in when he linked circadian misalignment to a range of diseases. However, this article also linked lack of sleep to psychological illnesses and stated that “problems sleeping are often a warning sign or a cause of impending depression, and can make people with bipolar disorder manic”. This correlation between sleep deprivation and psychological disorders alludes that the more an individual shifts their sleep schedule, the more at risk they are for certain diseases and disorders. The article also referenced the “internal clock” which also gets cues not just from the amount of light that is present, but also from the hormone melatonin. The secretion of melatonin in response to darkness, is what tells your brain that it is time for bed. By ignoring such signals, it causes a delay in your circadian rhythm. Continuously doing so, is what causes irreparable consequences.

According to the research done by Russell G. Foster and Leon Kreitzman in their article “The rhythms of life: what your body clock means to you!”, which is the article Dr. Cavanaugh provided for our class as background knowledge prior to his talk, the article states that, “biological clocks drive or alter our sleep patterns, alertness, mood, physical strength, blood pressure and every other aspect of our physiology and behavior”. This backs up both Dr. Cavanaugh when he listed diseases that can be a result of circadian misalignment, but also the New York Times, and their focus of psychological disorders. When individuals work against the sleep cycle that the body is accommodated to, they may be unaware of all the day to day deficiencies until the circadian misalignment becomes a pattern and the repercussions are more severe. Overall, no matter what the spin on sleep deprivation and circadian misalignment is, the results are never good.

References

Foster, Russell and Kreitzman, Leon. “The rhythms of life: what your body clock means to you!”. Nuffield Department of Clinical Neurosciences. Exp Physiol 99.4 (2014). 599-606.

Friedman, Richard. “Yes, Your Sleep Schedule Is Making You Sick”. The New York Times.  March 10, 2017.

Cavanaugh, Dan. “Using fruit flies to understand the consequences of circadian disruption”. Loyola University Chicago Neuroscience Seminar. April 16, 2019.