DNA could explain why you have difficulty falling asleep

 

Maybe you’re the kind of person who can jump into bed and almost instantly fall asleep, or maybe you lay awake at night struggling to catch some shut-eye. While there are certainly many factors that affect your quality and duration of sleep, scientists have found associations between your DNA and catching some Zs.

A person’s DNA houses a lot of otherwise unknowable information. Up until recent years, trial-and-error was the only way to figure out how a person’s body responds to different diets, lifestyles, and training programs. We now know DNA provides insight into these factors. The power of genome sequencing has added new answers to the question “Who am I?”

Your DNA can show if you’re predisposed to certain types of injury, provide certain nutritional insights (including sensitivity to caffeine), and much more. Did you know there are parts of your DNA that are associated with quality of sleep?

Optimal rest is necessary for both physical and mental health. These insights are especially important for athletes as sleep is a crucial part of muscle regeneration.

The CLOCK gene and sleep onset.

Have you ever been lying awake at night, trying to sleep but found yourself unable to drift off? It’s possible that your CLOCK gene is a contributing factor. This gene is often associated with sleep latency or sleep onset (the time it takes to fall asleep).

Essentially, the CLOCK gene is believed to affect an individual’s sleep signaling. Folks with the GG and AG genotypes may be predisposed to latent sleep onset. This may make it difficult for them to doze off when they lie in bed, which can result in sub-optimal sleep and more drowsiness during the day. These genotypes have also been associated with less early-morning  hunger.

Athletes with this genotype may experience improved performance and alertness outcomes during training sessions later in the afternoon. To mitigate the effects of latent sleep onset, one should practice good sleep hygiene – that is, habits that will help you to fall asleep. Consider prioritizing relaxing activities before sleeping and try to get to bed at the same time each night. To optimize these relaxing activities, be mindful of blue light.

The blue light emitted by TV, tablets, smartphones, and computers can disrupt your sleep patterns. Instead of cruising social media, watching TV, or playing video games before sleeping, try disengaging by listening to a book on tape, a podcast, or reading by a soft light. These relaxing activities will help you fall asleep faster and rest throughout the night.

Factoring in the number of studies conducted on this gene and its associations, the sample sizes of those studies, their consistent findings, and the population diversity of those featured in the studies, Athletigen has given this association an A grade for scientific confidence.

Sleep quality and your DNA.

The TNFα gene produces a signaling molecule, also called TNFα, that’s involved in regulating various functions in your body including sleep. Five separate studies have found a significant association between a variant of TNFα and sleep patterns. Interestingly, when mice were given extra TNFα, it increased their non-REM sleep duration and sleep intensity and decreased their REM sleep. Certain variants of TNFα can affect its expression, leading to individual differences in sleep disturbances and quality of sleep.

People with the GG genotype may have a higher tendency to experience increased sleep disturbances throughout the night. In some studies, GG individuals also reported higher levels of morning fatigue than A allele carriers.

For Athletes, sleep disturbances can hinder recovery during daily training or competition season. When considering environmental factors and DNA it can be difficult to pinpoint the source of fatigue, but reduced quality of sleep can negatively impact mood, motivation, and the overall perceived quality of any given day. These factors combined can have detrimental effects on how the mind and body handle a challenging training session or a competition, negatively affecting performance.

Relaxation is beneficial for everyone, but especially for those struggling with sleep quality. Practice relaxation techniques to calm your mind before going to bed. Try focusing on breathing by closing your eyes and taking deep, slow breaths. Consider attempting progressive muscle relaxation by tensing all your muscles as tightly as you can, then completely relaxing them. Work your way up from your feet to your head. These relaxation techniques will help you wind down by encouraging you to focus on your senses.

Athletigen has given this association a B confidence grade because the studies focused primarily on subject groups of European descent and more research is needed to understand the effect of this association in diverse ethnic populations.

Your DNA may contribute to restless sleep.

The BTBD9 gene is primarily associated with restless leg syndrome, however research suggests associations between this gene and restless sleep as well. Little is known about how this gene functions but there is some evidence that it plays a role in regulating iron levels, which may be linked to restless leg movements. People with the AA and AG genotype may experience a higher susceptibility to restless sleep.

Variants of this gene may result in involuntary muscle contractions, known as periodic leg movements, while sleeping. When this happens, you may be fully awakened or briefly disturbed without noticing, leading to less restful sleep. These nighttime movements might be a silent contributor to insomnia or daytime sleepiness.

This lack of restful sleep may affect how an athlete recovers post training. If you suspect that leg movements are disrupting your rest, you may want to consult a physician to help improve your sleep quality.

Restless leg symptoms can often be treated with lifestyle changes. Being active and exercising daily can be helpful in managing these symptoms. Choose activities that make use of your lower body including aerobic and lower-body resistance training. Disruptive leg movements at night tend to increase if you don’t move your legs throughout the day. Limit the amount of time you spend sitting at a desk by finding creative ways to stay active. Consider scheduling activities that require long periods of sitting in the morning rather than late in the day. Stretching your calves, quads and hips can also help alleviate symptoms.

Athletigen has given this association a B confidence grade. Further research in large groups of diverse ethnicities must be done before this association is given the highest confidence grade.

Is my DNA affecting how I sleep?

The answer to this question is yes. Everybody’s DNA affects how they sleep whether they know their genotype or not.

The only way to know if you carry these specific genotypes is to have your DNA analysed. Thanks to recent scientific innovations, DNA collection can now be done through a simple, non-invasive saliva swab. If you’re interested in learning more about your body, Athletigen can help.

Further reading.

Gajewski PD, Hengstler JG, Golka K, Falkenstein M, Beste C. 2013. The functional tumor necrosis factor α (308A/G) polymorphism modulates attentional selection in elderly individuals. Neurobiol Aging. 34(11): 2694.

Beste C, Heil M, Domschke K, Baune BT, Konrad C. 2010. Associations between the tumor necrosis factor alpha gene ( 308G→A) and event related potential indices of attention and mental rotation. Neuroscience. 170(3): 742 748.

Satterfield BC, Wisor JP, Field SA, Schmidt MA, Van Dongen HP. 2015. TNFα G308A polymorphism is associated with resilience to sleep deprivation induced psychomotor vigilance performance impairment in healthy young adults. Brain Behav Immun. 47: 66 74.

Beste C, Baune BT, Falkenstein M, Konrad C. 2010. Variations in the TNF α gene (TNF α 308G→A) affect attention and action selection mechanisms in a dissociated fashion. J Neurophysiol. 104(5): 2523 2531.

Aouizerat BE, Dodd M, Lee K, West C, Paul SM, Cooper BA, Wara W, Swift P, Dunn LB, Miaskowski C. 2009. Preliminary evidence of a genetic association between tumor necrosis factor alpha and the severity of sleep disturbance and morning fatigue. Biol Res Nurs. 11(1): 27 41.

Bower JE, Ganz PA, Irwin MR, Castellon S, Arevalo J, Cole SW. 2013. Cytokine genetic variations and fatigue among patients with breast cancer. J Clin Oncol. 31(13): 1656 1661.

Illi J, Miaskowski C, Cooper B, Levine JD, Dunn L, West C, Dodd M, Dhruva A, Paul SM, Baggott C, Cataldo J, Langford D, Schmidt B, Aouizerat BE. 2012. Association between pro and anti inflammatory cytokine genes and a symptom cluster of pain, fatigue, sleep disturbance, and depression. Cytokine. 58(3): 437 447.

Kripke DF, Shadan FF, Dawson A, Cronin JW, Jamil SM, Grizas AP, Koziol JA, Kline LE. 2010. Genotyping sleep disorders patients. Psychiatry Investig. 7(1): 36 42.

Riha RL, Brander P, Vennelle M, McArdle N, Kerr SM, Anderson NH, Douglas NJ. 2005. Tumor necrosis factor alpha ( 308) gene polymorphism in obstructive sleep apnoea hypopnea syndrome. Eur Respir J. 26(4): 673 678.

Lan F, Cao C, Liu J, Li W. 2015. Obstructive sleep apnea syndrome susceptible genes in the Chinese population: a meta analysis of 21 case control studies. Sleep Breath. 19(4): 1441 1448. Varvarigou V, Dahabreh IJ, Malhotra A, Kales SN. 2011.

A review of genetic association studies of obstructive sleep apnea: field synopsis and meta analysis. Sleep. 34(11): 1461 1468.

Zhang et al, Diversity of human clock genotypes and consequences. Prog Mol Biol Transl Sci. 119, 51-81 (2013). PMC4169291

Ziv-Gal et al, Genetic polymorphisms in the aryl hydrocarbon receptor signaling pathway and sleep disturbances in middle aged women. Sleep Med. 14 (9), 883-887. (2013). PMID 23768840.

 Garault et al, Ghrelin, sleep reduction and evening preference: relationships to CLOCK 3111 T/C SNP and weight loss. PLos One. 6(2). (2011). PMID 21386998

Katzenberg, D., Young, T., Finn, L., Lin, L., King, D.P., Takahashi, J.S. & Mignot, E. (1998) A CLOCK polymorphism associated with human diurnal preference. Sleep 21, 569–576

Mishima, K., Tozawa, T., Satoh, K., Saitoh, H., Mishima, M. The 3111T/C polymorphism of hCLOCK is associated with evening preference and delayed sleep timing in a Japanese population sample. Am J Med Genet. 133(1). (2004): 101–104. PMID:15578592

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