Is Your Circadian Rhythm Longer Than Average? Night Owl Versus Morning Person

Have you ever wondered why one person thrives on night shift while another can't stay awake and feels horrible? I have. Research shows that there may be personality traits, and genetic factors that contribute to a person being a night owl versus a morning person.

An article, "Night Owls and early birds have different personality traits," by Agata Blaszczak-Boxe suggests that being a night owl versus being a morning person can affect a person's well-being. Both groups studied by the University of Barcelona showed good qualities, but the night owls appeared to have more adverse difficulties.

I asked a couple of friends who I used to work nights with about their feelings regarding night shift and here is Susan's answer:

"I did nights at first because of my young children. But as they grew, I just stayed on nights because honestly I don't have to see management or be involved in the multiple rounds and questions asked of the day shift. I only worked weekends so I really did not see mangement." Sue worked 28 years on night shift and 13 on days.

Predominate qualities of the morning people were; persistence, resistance to fatigue, difficulties, and frustration. As a result there were lower levels of substance abuse and less depression.

Predominate qualities of night people were; impulsiveness, extravagance, and temperamental. They are not afraid to explore the unknown which can lead to exciting adventures. However, although they are more creative, they can be more susceptible to addictive and antisocial behavior, insomnia, even suicide.

Ana Adan is quoted as saying, "several studies have linked different circadian rhythm genes with the development of mood disorders, schizophrenia and drug consumption." Men who are night people were shown to be more at risk for mental disorders than their women counterpart.

Being a night person seems to fade as we grow older, possibly because of decrease in activity.

The article, "Nurses Are Talking About: Working the Night Shift," by Laura A. Stokowski, breaks down how nurses feel about working night shift.

Love nights 47% Hate nights 32% Undecided 21%

These numbers surprised me, probably due to my personal aversion to night shift. In the same article, nurses expressed reasons for liking night shift such as; more time with patients, less stress, and slower pace, even though they acknowledged constant fatigue and difficult schedules. These same nurses reported that as a young nurse, the night shift was great, but as they got older, it became less tolerable.

In a new study from April of this year in the article by Amanda Onion, "Are You A Night Owl? It May Be A Gene Mutation," that studied 70 people showed that those who suffered from delayed sleep disorder (DSPD) also carried the gene CRY1. These people have a delayed circadian rhythm and go to bed later, waking up later than the average. The reason that they believe this gene may drive the circadian clocks is because it was not present in the people who did not have DSPD. It has long been theorized that genetics play a role in our inner clocks, but this is the first real evidence.

The lead researcher, Alina Patke states that, "Carriers of the mutation have longer days than the planet gives them, so they are essentially playing catch-up for their entire lives." Our circadian rhythm dictates our daily lives. It tells us when to eat, when to sleep, and even regulates our body temperature. For all but 10% of the population, this is a 24 hour cycle, but for that small percentage, it is longer.

The CRY1 mutation is one "letter" different, and that causes the delayed sleep disorder. Patke pointed out that not everyone who is a night owl carries the gene mutation. There is a lot more to learn regarding our genes as they are related to our sleep/wake patterns.

Some of you have heard of 23andMe, a genetic identifier company very similar to Ancestry. 23andMe studied over 90,000 people and was able to glean 15 different versions of genes that are connected to a person being a late riser, or early riser. Their article, "This one factor may explain why you're a morning person or a night owl," by Tanya Lewis.

In this article, our circadian rhythm is called a chronotype. David Hinds, the main researcher in the genome-wide association study linking genes to a specific trait, used spit samples to do their research along with surveys filled out by the participants. Out of the 135,000 people who filled out the survey, 75.5% of the people fell into a category of either night owl or morning person.

"Of the 15 genetic variants the study found that were linked to being a morning person, seven of them were near genes that are known to play a role in circadian rhythm. And some of these genes were also near ones involved in sensing light from our eyes." I found this so fascinating, that they can be so detailed with our genetic code as to link them with functions of our body that tell us when to be awake or when to sleep.

As with the previous study, this one also found similar traits among the two groups. The night owls often suffered from insomnia and sleep apnea while the morning people less likely to need 8 hours of sleep, they sweat while sleeping, and more apt to sleep walk. Because a lot of this information comes from surveys, it is limited because of the self reporting aspect.

Ivah also gave me some insight into her life of night shift:

"Just in case you are unaware, night shift people are a couple of bubbles off of plumb. More than a little strange. On night shift you actually had time to get to know your patients and families (and we didn't have the clipboards breathing down our necks). Evenings were good when my children were still in elementary/middle school. Yep, I would say that I am pretty much a night person. Can't do all night (now) but most nights I am not in bed before 12:30 or 2am." Ivah spent 19 years on 12 hour night shift, 3 years on 3-11, and 1 year on day shift. She is now retired and is 75 years young.

While gathering information for this article, I ran across an article that caught my attention called, "Night Shifts may hinder body's ability to repair DNA damage," taken from an article published by BMJ. They looked at healthcare workers on the night shift and evaluated their urine for the hormone melatonin.

The researchers in this study had actually already finished a study of urine samples that had showed a lower level of the chemical 8-OH-dG, a "by-product of active DNA tissue repair," in day sleepers. They went back and studied the stored urine samples to further explore the idea that night shift workers would also have lower levels of melatonin. Their idea was backed up by the fact that there was lower levels of melatonin in the night shift workers than those who sleep at night.

Melatonin has been thought to help in the repair of DNA damage caused by oxygen free radicals by giving the genes a boost. Because of the limitations on the study, the participants were "mostly white, working in healthcare and of similar age," no concrete conclusions can be drawn. However, it is a step towards understanding our body and how our work and life habits affect our health.

There are many reasons why people chose to work on a night shift; child care, less management, financial, and it allows for a better relationship/crew of the patients. Thank you to Susan and Ivah that gave their input on working night shift, Ivah was my preceptor as a brand new nurse and I have never forgotten her wit and knowledge. She was a fantastic mentor and I appreciate her for guiding me through that difficult and exciting time. Susan was a co-worker during that same time and I have never laughed so much at work than with her. I can still vividly remember some of the subjects that left me on the floor in tears after laughing so hard. However, I do have to say that it is her fault that I gained 10 pounds that first year because of her wonderful cookies. She was a great nurse and I learned so much from watching her.

Tell us your thoughts about working nights versus days. Include how you feel physically and mentally so we can get a full picture of how it affects you.

References

Blaszczak-Boxe, Agata. "Night owls and early birds have different personality traits." 24 July, 2014. CBSNEWS.com. Web. 10 April, 2017.

Lewis, Tanya. "This one factor may explain why you're a morning person or a night owl." 2 Feb. 2016. BusinessInsider.com. Web. 10 April, 2017.

"Night shifts may hinder body's ability to repair DNA damage." 26 June, 2017. ScienceDaily.com. Web. 28 June, 2017.

Onion, Amanda. "Are You A Night Owl? It May Be A Gene Mutation." 7 April, 2017. HuffingtonPost.com. 10 April, 2017.

Stokowski, Laura A. RN. "Nurses Are Talking About: Working the Night Shift." 11 Jan. 2013. Medscape. Web. 10 April, 2017.