Russel Walters – Somn

Bed Comfort and Sleep; Somn sleep data blog series

Bed Comfort and Sleep; Somn sleep data blog series

We explored how bed comfort and sleep are related based on self-reported sleep patterns and perception of sleep.  Do more comfortable beds lead to better sleep? Can you buy better sleep?

Somn Beds

Methods: 3,007 adults completed an expanded version of the Somn Sleep Assessment that included questions about their bed comfort and their sleep.

Data Question 1: Does bed comfort affect sleep?

The first clear finding is that a lot of people are sleeping on “bad” beds: over 20% of subjects reported sleeping on an uncomfortable bed either “always” or “frequently.”  People who are sleeping on uncomfortable beds also report worse sleep, with significantly higher insomnia scores (15.1 vs 16.9), p<0.001. Sleep onset latency, or how long it takes to fall asleep, was an average of 20 minutes longer for those who “always” sleep on an uncomfortable bed compared to those that said they “never” do.

Correspondingly, all this bad sleep on an uncomfortable mattress results in being tired during the day.  So it’s not surprising that bed discomfort was associated with daytime sleepiness (higher Epworth Daytime Sleepiness scores, 8.3 vs 9.5, p<0.001). Furthermore, reported bed comfort was highly correlated with alertness at work (p<0.001). Maybe you can talk your employer into buying you a new bed!

Somn bed comfort data blog: ISI

Data Question 1.1: So is an uncomfortable bed a nightmare? 

Well maybe, but we didn’t exactly explore that. One interesting thing we did learn was that nightmare frequency was significantly higher for those who slept on an uncomfortable bed (1.62 nightmares/wk vs 0.91/wk, p<0.001). Speculating, perhaps, that because sleep is less sound on an uncomfortable mattress, more dreams and nightmares are remembered.

Somn bed comfort data blog: nightmares

Conclusion 1: Yes – Uncomfortable beds are correlated with bad sleep

Based on the two questions above, bed discomfort is clearly associated with worse sleep, though we can’t explicitly know the causality. This is an important question: should people who are unhappy with their sleep begin by changing their behaviors or changing their bed… or both? In many ways, changing a bed is much easier than sustained behavior change, or habitual behaviors.

Data Question 2: Can money buy you happiness in your sleep?

Previous sleep-related studies have shown that wealthier sleepers often have more complaints. This is markedly so in the case of baby sleep: wealthier parents tend to report more problems with their children’s sleep, even though their children actually tend to sleep a little better than children from lower socioeconomic groups.  Like The Princess and the Pea, when you have more wealth does that just lead to more complaints?

In the Somn Sleep Assessment research, perception of bed comfort was positively correlated with both age and income. 28% of subjects with household income below $30,000 reported an uncomfortable bed compared with only 8.0% of subjects with household incomes over $130,000. To be clear, from this data we could only correlate sleep with household income, and not how much a bed cost. But there is likely a very strong correlation between household income and bed cost.

Somn Bed Comfort and Income

Conclusion 2: Yes – You can buy better sleep with a comfortable mattress

With bed comfort, money does seems to buy bed happiness. It appears that you can buy happy sleep, with a quality new mattress. This is supported by separate research that showed that replacing an old mattress reduced back pain and improved sleep.

Is it time for a new mattress?

Here is the full abstract from this data that was presented at SLEEP 2019.

Explore Your Sleep

Title: Bed comfort and sleep: change your bed or change your behavior?

Authors: Russel M. Walters, Jordana Composto

Introduction: We explored how bed comfort was related to self-report sleep patterns and perception of sleep.  

Methods: 3,007 adults (2,793 females) between the ages of 18 to 86, recruited through social media, completed a comprehensive online sleep assessment modified for mobile experience, including the Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Sleep Hygiene Index, and questions about attempted sleep solutions.  

Results: 20.4% of subjects reported sleeping on an uncomfortable bed either “always” or “frequently.”  The perception of bed comfort was positively correlated with both age and income.  28% of subjects with household income less than $30,000 reported an uncomfortable bed compared with only 8.0% of subjects with incomes over $130,000.  Participants who reported sleeping on an uncomfortable bed had significantly higher ISI scores (15.1 vs 16.9), p<0.001.

Self-reported sleep onset latency (SOL) was associated with bed discomfort, with an average 20 minutes longer SOL for those that “always” sleep on an uncomfortable bed compared to “never.” Bed comfort was not associated with number or duration of night wakings.  Nightmare frequency was also significantly higher for those that slept on an uncomfortable bed (1.62 nightmares/wk vs 0.91/wk, p<0.001).  Bed discomfort was associated with daytime sleepiness with higher ESS scores (8.3 vs 9.5), p<0.001.  Furthermore, reported bed comfort was significantly correlated with alertness at work (p<0.001).

Conclusions: While bed discomfort is clearly associated with increased likelihood of insomnia, nightmares, and daytime sleepiness, we cannot know explicitly the direction of the causality. This is an important question that needs more exploration.  Should individuals who report poor sleep and an uncomfortable bed begin by changing behaviors or changing their bed… or both?

Learn about Narcolepsy & where to get help

Narcolepsy is a sleep and neurological disorder that disrupts the normal sleep/wake cycle and is characterized by quick entry into Rapid Eye Movement (REM) sleep from waking.  In other words, people can rapidly fall asleep at times through the day and quickly start dreaming.  This is often disorienting and can have significant impacts on daily life.  Narcolepsy is fairly rare and affects about 0.5% of adults. What causes narcolepsy is not fully understood.  However it appears that both genetic and environmental factors that are related to the immune system.

Symptoms of narcolepsy include:

During the day:

  • Tiredness during the day
  • Sleep attacks (rapid onset of sleep)
  • Cataplexy – when strong emotion (e.g laughter, excitement) causes a sudden loss of muscle tone or limpness
  • Sleep paralysis
  • Hallucinations

At night:

  • Disrupted nighttime sleep
  • Difficulty staying asleep

Narcolepsy is typically slow to be diagnosed and people often suffer untreated for years. There are treatments for narcolepsy including both prescription medications and lifestyle modification.

Explore more

The Somn Sleep Assessment contain some questions that are related to screening tools for narcolepsy.  These questions and analysis are elements of the Body Sleep Factor.  While we can’t diagnose narcolepsy, a good immediate next step is a online screening for narcolepsy. Narcolepsy screeners will ask you about your sleepiness during the day and the likelihood that you fall asleep in different situation. Next it will ask you questions from the Swiss Narcolepsy Scale. A narcolepsy screen can be found here and you can complete it in just a few minutes.

If you think you may have narcolepsy, talk to your healthcare provider. You can find more information at the Narcolepsy Network, a national nonprofit organization dedicated to increasing early diagnosis of narcolepsy, advocating for and supporting persons with narcolepsy and their families, and promoting critical research for treatment and a cure.

Other resources to help with your sleep

Explore Your Sleep

Learn about Obstructive Sleep Apnea (OSA) & where to get help

Obstructive sleep apnea (OSA) is a specific type of sleep-disordered breathing. When someone has OSA, the airway is blocked during sleep, preventing the passage of air and leading to pauses in breathing. These blockages are often attributed to a loss of muscle tone around the airway, changes in tissue elasticity over time, and changes in hormone levels (particularly amongst women).

The breathing pauses due to OSA, deprive the brain of needed oxygen during sleep, and are associated with cardiovascular disease, cognitive issues, and other factors that can impact your quality of life.

Symptoms of obstructive sleep apnea:

During the day:

  • Sleepy during the day
  • Poor concentration & memory

At night:

  • Heavy and persistent snoring which is often worse when on your back or after alcohol
  • Sudden or startled wakening, especially with noisy breathing

Explore more

The Somn Sleep Assessment contain some questions that are related to screening tools for obstructive sleep apnea.  These questions and analysis are elements of the Body Sleep Factor.  While we can’t diagnose obstructive sleep apnea, a good immediate next step is the STOP-Bang obstructive sleep apnea screening tool; a quick self-reported question set that is an effective screening tool for OSA. It can be found here: STOP-Bang, and you can complete it in just a few minutes.

If you think you may have OSA, talk to your healthcare provider. They may recommend treatments such as Continuous Positive Airway Pressure (CPAP). You can find more information here.

Other resources to help with your sleep

Explore Your Sleep

Somn Personal Melatonin Test

Everyone is unique, and a personalized medicine approach to melatonin may help to improve your sleep. We have created the easy at-home patent pending Somn Personal Melatonin Test.

Zeitgebers

Your need and drive for sleep is determined by circadian rhythms and the interaction of these processes defines the timing and duration of your sleep. Many factors such as genetics, feeding, exercise, stress, menstrual cycle, hormones, and medications also influence our sleep need.  

Circadian biology

Different factors affect specific parts of sleep. Our internal clock, which is present in cells and neurons in the body, is influenced by light-dark cycles as well as eating (Santhi et al. 2016). This clock plays an important role in the sleep/wake cycle and enables the transition of different sleep cycles (Guidozzi, 2015). Circadian rhythms influence not only our sleep but also alertness, mood, hormone release, all of which are controlled by our internal clock (Achermann & Borbély, 2011).

Due to changes in reproductive development and changes in melatonin, a hormone that alters sleep, adolescents experience many changes in their sleep-wake cycle. During this age span, there is reduced deep sleep (N3) and REM sleep as well as an increase in delayed sleep phase. (Jenni and Carskadon, 2004; Jenni et al., 2005; Kurth et al., 2010; Lui et al., 2017). In other words, adolescents are going to bed later and not getting enough of the deep sleep they need to feel rested and refreshed.

The Somn Personal Melatonin Program

Tried melatonin before? And it didn’t work so well? Likely the melatonin was not well matched to your individual needs. This is why we created the Personal Melatonin Test.

Learn more about the Somn Personal Melatonin Program

The science of how melatonin works to bring sleep, from the Lab

This From the Lab scientific article on the science of how melatonin works to bring sleep was written by Russel M. Walters, PhD, chief science officer at Somn.

Zeitgebers

We need to first understand what is sleep and what determines how much we sleep. Sleep is not a passive event, but rather an active process involving physiological changes that occur throughout the brain and body (Guidozzi, 2015). Sleep is governed by two processes (Borbély, 1982): one oversees the time of day to sleep during a 24-hour period (Daan et al., 1984) and the other gauges the need for sleep (Achermann & Borbély, 2011).

Your need for sleep is determined by circadian rhythms and the interaction of these processes defines the timing and duration of your sleep. Throughout the day or with extended wakefulness, our sleep pressure increases and thus, the need for sleep increases (Dijk & Franken, 2005). Yet, many factors such as genetics, feeding, exercise, stress, menstrual cycle, hormones, and medications also influence our sleep need.  

Circadian biology

Different factors affect specific parts of sleep. Our internal clock, which is present in cells and neurons in the body, is influenced by light-dark cycles as well as eating (Santhi et al. 2016). This clock plays an important role in the sleep/wake cycle and enables the transition of different sleep cycles (Guidozzi, 2015). Circadian rhythms influence not only our sleep but also alertness, mood, hormone release, all of which are controlled by our internal clock (Achermann & Borbély, 2011).

Due to changes in reproductive development and changes in melatonin, a hormone that alters sleep, adolescents experience many changes in their sleep-wake cycle. During this age span, there is reduced deep sleep (N3) and REM sleep as well as an increase in delayed sleep phase. (Jenni and Carskadon, 2004; Jenni et al., 2005; Kurth et al., 2010; Lui et al., 2017). In other words, adolescents are going to bed later and not getting enough of the deep sleep they need to feel rested and refreshed.

References on the Science of Melatonin:

How the environment impacts your sleep health, from the lab series

This From the Lab scientific article on how the environment impacts your sleep was written by Russel M. Walters, PhD, chief science officer at Somn.

The bed is the single location where we spend the most time and hence have the longest environmental exposure. And yet this environment is poorly described or understood and under studied. The environment impacts your sleep in many complex ways. The impact or effect size of each different environmental impact is small, but the overall impact of the sleep environment is likely clinically meaningful.

Zeitgebers

There is wide agreement that environmental factors affect sleep and health. Zeitgebers are environmental phenomena that regulate the body’s daily circadian rhythms. Typically considered as naturally occurring phenomena (such as sun light and temperature), in modern societies social activities – especially eating (Stephan 2002), and other artificial sources (e.g. house lights, your phone) – can also have daily variation that function as zeitgebers.

Zeitgebers such as the light and dark cycle of the day or the warmer daytime and colder nighttime help to entrain people onto the 24-hour clock. In the absence of zeitgebers and social responsibilities, a person would have a free running clock that would be determined by their internal circadian clock.

Circadian biology

Many bodily systems have a daily, or circadian, variation that both supports the regulation of sleep and wake and also prepares and provides the body what it needs at the appropriate time of day. This body’s circadian clock(s) are entrained to zeitgebers, external stimuli that vary over the course of the day, such as sunlight and temperature.  The chart below shows some of the bodily systems and functions that have a circadian variation.  Melatonin and cortisol serve key roles in managing your body’s biological clock as well as managing your sleep and wake cycles. Under normal conditions melatonin is produced by the body, endogenously, in the evening and overnight. As the body transitions from sleep during the night to waking in the morning, melatonin falls and cortisol rises. Body temperature and blood flow that had been decreasing over the course of the night begins to increase.

Scientists are increasingly realizing the importance and wide extent of biological systems that have circadian rhythm variations. Yet, most experimentation is limited to model species (flies, rodents, plants) and most human studies take place in highly controlled environments (typically deep in the basement of medical systems). In studying environmental effects on humans, much is lost if the study occurs outside of their “natural” environment. Recently, Skarke brought these concepts out of the lab and into the real-world environment in a pilot study of six subjects (Skarke 2017).

Read more about melatonin here.

Sleep & environment:

While the field of chronobiology has grown in prominence, the field of sleep medicine is dominated by pulmonologists focused on disrupted breathing (i.e. apnea and snoring) and by behavioral psychologists focused on changing behaviors and routines in order to improve the sleep of their patients. This is entirely appropriate as these two areas cover the majority of effects on sleep. Outside of sleep medicine, the field of design thinks a great deal about how people interact with their environment, but almost exclusively while people are awake.

Typically, environmental influences are thought to affect sleep by disrupting sleep, promoting an awakening from sleep, or delaying falling asleep. Alternatively, certain environment influences can bring a user into sleep or return a user to sleep. Acoustic stimulation is being used to enhance slow waves during sleep and lead to deeper sleep (Ngo 2013). The environment that a user experiences during wake can have significant influences on how the user sleeps later in the day. As mental health significantly impacts sleep health, the environmental experience during wake would be expected to also affect sleep. For example, the experience of a park has been shown to reduce salivary cortisol (Roe 2013) (Thompson 2012). There are a number of ways that the environment impacts your sleep including:

  • Sound (intensity, frequency, timing variation, scene, location & movement)
  • Light (intensity, color, timing variation, information content, location & movement)
  • Mechanical: vibration / draft / movement
  • Temperature
  • Humidity
  • Smells and air quality (pollution, allergens, etc.)

The sensorial experience of each environmental factor is the collection, or summation, of the array of sources; this has both temporal and spectral variations. A good example of this complexity can be seen in the ecological soundscapes produced in nature and recorded by Pijanowski. (Pijanowski 2011). Additionally, each factor has its own response surface, that is to say what levels (both intensity and frequency) are negative or positive for sleep and at different stages of sleep which is influenced by the signal transduction and also the interpretation.

Light and sleep

Modern societies modify their environments in ways that dampen or eliminate the natural daily variation: artificial light during times of dark; thermostats to warm cold nights; noise during times of quiet. It is telling that these additions to the natural state are often called pollution. There are suggestions (Wyse 2011)and some evidence that this more subtle control of the built environment is detrimental to health; light at night have been shown to cause depression-like symptoms in rodents (Bedrosian 2013) (Fonken 2013). There is conflicting evidence on the influence of the moon on sleep, perhaps due to large geospatial variability of anthropogenic sources on light at night.

Sounds and sleep

Not surprising sound can disrupt sleep, but there is also evidence that sound can support or even enhance sleep. Sound from transportation sources (rail, planes, roads) are the relatively more studied environmental impact (Bodin 2017, Hong 2010, Passchier 2002). Sounds in hospital settings have been found to have detrimental effects on health and recovery (Huang 2015).

Studies have been conducted in ecologically valid settings (i.e. subject’s bedroom) (Aasvang 2011) and also in controlled lab settings (Marks 2007). The effects of natural sounds have been largely ignored, and natural sounds can be rather loud in wetter locations. Silence is not the natural state for sleep; night and especially early evening are not a quiet time in nature. Healthy ecosystems have diverse sounds that rise into the evening and become quieter overnight (Pijanowski 2011). Sound has fewer impactful sources than light, but there is not a convenient way to measure or sum the many possible sources.

Sound has also been used to drive people into deeper sleep.  There are a few commercial products that have brought this science out of the research lab and into the bedroom.  Dreem and Hibernate use acoustic stimulation during sleep to bring sleepers into deeper sleep.

Other environmental factors

There is a long tail of many other possible environmental factors that could influence sleep that are little studied. Vibration is being explored in infant beds (Zuzarte 2017), but there is little evidence. While it is well known that core body temperature has a daily circadian variation, dropping through the night, it is unclear how the sleep environment temperature and humidity support or interfere with this process. The information in the scene or setting of sleep is well known to be important (e.g. the first night under study is often not used in analysis) but is also little studied. Things like tree cover and proximity to water may ease stress, or air quality may have a complex cascade of interaction that impede sleep.

Now that that you understand how the environment impacts your sleep,

What to do next:

Reference on how the environment impacts your sleep

TA Bedrosian, ZM Weil, RJ Nelson, Chronic dim light at night provokes reversible depression-like phenotype: possible role for TNF, Molecular Psychiatry, 2013, 18, 930.

EC Bodin, J Selander, Burden of disease from road traffic and railway noise – a quantification of healthy life years lost in Sweden, Scand J Work Environ Health 2017;43(6):519.

LK Fonken, RJ Nelson, Dim light at night increases depressive-like responses in male C3H/HeNHsd mice, Behavioural Brain Research 243 (2013) 74.

Hong J, et al. The effects of long-term exposure to railway and road traffic noise on subjective sleep disturbance, J Acoust Soc Am. 2010, 128(5), 2829.

HW Huang, et al., Effect of oral melatonin and wearing earplugs and eye masks on nocturnal sleep in healthy subjects in a simulated intensive care unit environment: which might be a more promising strategy for ICU sleep deprivation? Huang et al. Critical Care (2015) 19:124.

GM Aasvang, et al. A field study of effects of road traffic and railway noise on polysomnographic sleep parameters, J Acoustical Soc of America 2011, 129, 3716.

G Kecklund, J Axelsson, Health consequences of shift work and insufficient sleep BMJ, 2016; 355.

A Marks, B Griefahn, Associations between noise sensitivity and sleep, subjectively evaluated sleep quality, annoyance, and performance after exposure to nocturnal traffic noise. Noise Health, 2007, 9:1.

JA Mindell, R Gould, L Tikotzy, ES Leichman, RM Walters, Norm-Referenced Scoring System for the Brief Infant Sleep Questionnaire–Revised (BISQ-R), Sleep Medicine, 2019.

HV Ngo, T Martinetz, J Born, M Molle, Auditory closed-loop stimulation of the sleep slow oscillation enhances memory, Neuron, 2013, 78(3):545.

W Passchier-Vermeer, H Vos, JH Steenbekkers, FD van der Ploeg, K Groothuis-Oudshoorn, Sleep disturbance and aircraft noise exposure. Exposure-effect relationship. TNO Prevention and Health TNO-Report Nr, 2002, 027.

Pijanowski, et al., Soundscape Ecology: The Science of Sound in the Landscape, BioScience, 203, 2011

JJ Roe, et al. Green Space and Stress: Evidence from Cortisol Measures in Deprived Urban Communities, Int. J. Environ. Res. Public Health 2013, 10(9), 4086.

Skarke, C., et al. (2017). A pilot characterization of the human chronobiome. Scientific reports, 7(1), 1-12.

FK Stephan, The “Other” Circadian System: Food as a Zeitgeber, J Biological Rhythms, 2002, 17(4), 284.

CW Thompson, et al., More green space is linked to less stress in deprived communities: Evidence from salivary cortisol patterns, Landscape and Urban Planning, 2012, 105(3), 221.

CA Wyse, et al. Circadian desynchrony and metabolic dysfunction; did light pollution make us fat?, Medical Hypotheses, 2011, 77, 1139. I Zuzarte, P Indic, B Barton, D Paydarfar, F Bednarek, et al. Vibrotactile stimulation: A non-pharmacological intervention for opioid-exposed newborns, PLOS ONE, 2017, 12(4): e0175981.