Sleep Architecture in Perimenopause
During perimenopause, the period of transition before menopause, fluctuations in hormones such as estrogen and progesterone can cause multiple physical and emotional symptoms. One of these symptoms is changes in sleep including night sweats, insomnia, and changes to your sleep architecture.
Here is an overview on sleep architecture and changes during perimenopause.
What is sleep architecture?
Sleep architecture is the breakdown of the stages and cycles of sleep (Suni & Singh, 2023). Your sleep is composed of multiple sleep cycles, each with distinct stages and sub-stages. There are two main categories of sleep stages called non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep (Suni & Singh, 2023).
Non-Rapid Eye Movement (NREM) Sleep: NREM sleep has three stages. It becomes more difficult to wake a person up the higher the stage they are in. Sleep begins with NREM sleep before progressing to REM sleep (Colton & Altevogt, 2006).
Stage 1 (N1): This stage typically lasts for 1-7 minutes and makes up 2-5% of total sleep (Colton & Altevogt, 2006). Because this is the first stage of sleep, it is easily disrupted by noise or other disturbances like changes in light (Colton & Altevogt, 2006).
Stage 2 (N2): This stage lasts longer than N1, lasting between 10-25 minutes during the sleep cycle (Colton & Altevogt, 2006). With each sleep cycle during the night, this stage gets longer and makes up 45-55% of total sleep time (Colton & Altevogt, 2006). During this stage, brain activity begins to slow with short bursts of activity, which are hypothesized to prevent waking up due to external stimuli (Suni & Singh, 2023).
Slow Wave Sleep [Stage 3 (N3) and Stage 4 (N4)]: Stages 3 and 4 are also referred to as slow wave sleep (SWS) due to the characteristic delta waves that appear on an ECG during these stages(Colton & Altevogt, 2006). Slow wave sleep may also be called “deep sleep” (Suni & Singh, 2023). During these stages, muscle tone, pulse, breathing rate, and brain activity relax further (Suni & Singh, 2023). Deep sleep mostly occurs during the first half of the night and during the earlier sleep cycles, N3 makes up 3-8% of sleep (Suni & Singh, 2023; Colton & Altevogt, 2006). N4 may last for 20 minutes and up to 40 minutes and makes up 10-15% of sleep (Colton & Altevogt, 2006).
Rapid Eye Movement (REM) Sleep: During REM sleep, brain activity begins to pick up. REM sleep is also marked by atonia, a paralysis of the muscles, with the exception of those involved in breathing and the eye muscles (Suni & Singh, 2023). REM sleep is important for consolidating memory, learning, and dreams mostly occur in the REM stage although they can occur in all stages of sleep (Suni & Singh, 2023). Relaxed muscles during REM stage likely function to prevent physical reactions to dreams (Colton & Altevogt, 2006). Typically, you do not enter REM until you’ve been asleep for 90 minutes and REM lasts for longer amounts of time the longer you’ve been asleep up to over an hour (Suni & Singh, 2023). REM eventually makes up for 25% of sleep for adults (Suni & Singh, 2023).
Why is sleep architecture important?
Each of the sleep stages is important for proper recuperation and recovery from the previous day (Suni & Singh, 2023). People who struggle to properly enter deep sleep stages can be impacted emotionally and physically (Suni & Singh, 2023). Changes in your sleep architecture patterns can cause feelings of inadequate sleep, despite enough time spent in bed.
How does perimenopause change your sleep architecture?
With age, women have larger changes in sleep efficiency, total sleep time, percentage of stage 1 (N1) sleep, and REM latency (the amount of time asleep before entering the first REM cycle) than men (Kravtiz & Joffe, 2011). These changes are also exacerbated during perimenopause due to changing levels of estrogen and progesterone (Kravtiz & Joffe, 2011).
Here are some of the specific sleep changes during perimenopause that can impact your sleep architecture:
Insomnia: As many as 59% of perimenopausal women have reported having insomnia symptoms (Ciano et al., 2017). This makes it difficult to fall asleep and can disrupt the normal progression through the stages of sleep.
Changes in Slow Wave Sleep (SWS): There is conflicting information regarding how perimenopause impacts SWS, however some studies have found that perimenopausal and postmenopausal women have more SWS than pre-menopausal women (Baker et al., 2018; Kravtiz & Joffe, 2011). This could indicate a recovery response due to sleep deprivation from other sleep disturbances.
Increased Wakefulness: Fluctuating estrogen can cause rapid swings in internal body temperature, a phenomenon known as hot flashes. Hot flashes that happen at night are called night sweats and one study found that 69% of hot flashes caused wakefulness (Baker et al., 2018). Even if hot flashes do not cause you to wake up, they are correlated with poor sleep quality, which might make even long periods of being asleep feel inadequate (Baker et al., 2018).
Changes in REM Sleep: During hormone cycling in perimenopause, lower levels of estrogen and progesterone increase the amount of time that the body spends in REM during sleep (Dorsey, de Lecea & Jennings, 2020). Among perimenopausal women with insomnia, they are more likely to be able to recall their dreams, creating a cycle of stressful dreams preventing them from falling asleep the next night (Lee et al., 1993).
Shifts in Circadian Rhythm: Estrogen and progesterone fluctuations can cause changes in normal sleep and wake times. This causes changes in the normal circadian rhythm that might make cycling through the stage of sleep difficult (Suni & Singh, 2023).
How can you “treat” perimenopause-related changes in sleep architecture?
Consistent Sleep Routine: Maintaining a relatively steady sleep schedule can help to train your body to regulate your circadian rhythm and cycle through the stages of sleep.
Relaxing Bedtime Routine: A consistent and relaxing bedtime routine can help reduce the amount of time you are awake in bed before falling asleep. Managing your stress can also be beneficial.
Optimize Sleep Environment: An environment that is quiet, dark, and your preferred temperature will help you fall asleep and remain asleep during the night. Consider using an eye mask or ear plugs if you are prone to waking up during sleep from external stimuli.
Stay Active: A regular exercise routine can help to regulate your circadian rhythm.
Diet: Avoid drinking caffeinated beverages before bed and be conscious of compensating for a poor night’s sleep with excess caffeine in the morning.
In conclusion, perimenopausal women can experience insomnia, changes in slow-wave sleep (SWS), wakefulness due to hot flashes and night sweats, changes in REM sleep, and shifts in circadian rhythms, all of which can impact sleep architecture. Regular communication with your healthcare provider is important when beginning a new bedtime routine or if you have concerns about how perimenopause is impacting your sleep. Practicing good sleep hygiene can help to regulate your sleep architecture and keep you feeling happy and healthy.
Disclaimer: At It’sFetch.co we strive to provide valuable and reliable health information through our blog. We believe in empowering individuals to make informed decisions about their health and well-being. However, it is important to understand that the content on our blog is not intended to replace the advice, diagnosis, or treatment provided by a qualified medical professional.
Sources
Baker, F. C., Lampio, L., Saaresranta, T., & Polo-Kantola, P. (2018). Sleep and sleep disorders in the menopausal transition. Sleep medicine clinics, 13(3), 443-456.
Ciano, C., King, T. S., Wright, R. R., Perlis, M., & Sawyer, A. M. (2017). Longitudinal study of insomnia symptoms among women during perimenopause. Journal of Obstetric, Gynecologic & Neonatal Nursing, 46(6), 804-813.
Dorsey, A., De Lecea, L., & Jennings, K. J. (2021). Neurobiological and hormonal mechanisms regulating women’s sleep. Frontiers in neuroscience, 14, 625397.
Institute of Medicine (US) Committee on Sleep Medicine and Research; Colten HR, Altevogt BM, editors. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Washington (DC): National Academies Press (US); 2006. Available from: https://www.ncbi.nlm.nih.gov/books/NBK19960/ doi: 10.17226/11617
Kravitz, H. M., & Joffe, H. (2011). Sleep during the perimenopause: a SWAN story. Obstetrics and Gynecology Clinics, 38(3), 567-586.
Lee, J. H., Bliwise, D. L., Lebret-Bories, E., Guilleminault, C., & Dement, W. C. (1993). Dream-disturbed sleep in insomnia and narcolepsy. The Journal of nervous and mental disease, 181(5), 320-324.
Suni, E., & Singh, A. (2023, December 8). Stages of sleep: What happens in a sleep cycle. Sleep Foundation. https://www.sleepfoundation.org/stages-of-sleep