Sleep Health and Human Performance

• Main goals:

  • Characterizing environmental, social and behavioural determinants of sleep health

  • Characterizing health outcomes of sleep health

Sleep Health

• Sleep is important for health!

  • Cardiovascular health

  • Cognitive health

  • Mortality

Deficient Sleep

• Poor sleep

• Short-sleep

• Fragmented sleep

• Sleep disorders

Definition

• Sleep health:

  • Sleep health is a multidimensional pattern of sleep-wakefulness, adapted to individual, social and environmental demands, that promotes physical and mental well-being

  • Good sleep health is characterized by subjective satisfaction, appropriate timing, adequate duration, high efficiency, and sustained alertness during waking hours

Sleep Health Dimensions

• Sleep duration: the total amount of sleep obtained per 24 hours

• Sleep continuity or efficiency: the ease of falling asleep and returning to sleep

• Timing: the placement of sleep within the 24h day

• Alertness/sleepiness: the ability to maintain attentive wakefulness

• Satisfaction/quality: the subjective assessment of good or poor sleep

  → R (regularity) you

  • S (satisfaction)

  • A (alertness)

  • T (timing)

  • E (efficiency)

  • D (duration)

Framework

[IMAGE p.10]

Physical Environmental Exposures that May Affect Sleep Health

• Noise

• Air quality

• Temperature and humidity

• Light at night (LAN)

Noise

• Noise: unwanted sound or set of sounds

  • Audible acoustic phenomenon that adversely affects or may affect people

• Noise affects objective sleep measures:

  • Increases awakenings

  • Increases sleep latency

  • Shortens sleep → decreases sleep efficiency

  • Fragments sleep → less SWS, less REM sleep, more stage 1 sleep

Main Sources

• Transportation

• Industrial (ex: wind turbines, neighbourhoods)

Effects of Traffic Noise on Sleep

[IMAGE p.18]

Noise Complaints and Sleep

• Perception + disturbance = annoyance

  → Environmental noise exposure should be evaluated by means of the estimated noise annoyance

• Noise complaints are associated with subjective sleep measures:

  • Associated with insomnia

  • Associated with poor sleep quality

• There may be reverse causation because insomniacs may complain more about noise or be more sensitive to noise

Outdoor Air Pollution and Sleep

• Higher levels of PM10 and PM2.5 are associated with higher sleep disturbance (sleep disordered breathing, sleep quality and sleepiness)

  • These particles irritate respiratory pathways and lungs

• Main source: transportation

Indoor Air Quality and Sleep

• Increased ventilation = decreased CO2

  • More deep sleep

  • Less awakenings

  • Better subjective sleep

  • Improved performance

Light at Night

• Living in areas with greater outdoor light at night is associated with:

  • Delayed bedtime and wake up time

  • Shorter sleep duration

  • Increased daytime sleepiness

  • Increased dissatisfaction with sleep quantity and quality

  • Increased likelihood of having a diagnostic profile congruent with a circadian rhythm disorder

Temperature

• Optimal temperature: 20 degrees

• Optimal range: 17 between 28 degrees

• Increases in temperature beyond the threshold of 28 degrees seem to be more disruptive than colder temperatures

• Humidity ranges between 40% and 60%

Built Environment Determinants of Sleep Health

1. Green space, walkability

2. Public lighting

3. Zoning (ex: many bars/restaurants near house)

4. Traffic infrastructure (highways)

Social Determinants of Sleep Health

• Norms

• Social connection/isolation

• Social cohesion

• Safety/violence

Behavioural Determinants of Sleep Health and its Predictors

• Exercise

• Commute

• Diet

Predictors

• Parks and sports facilities

• Bike paths and public transit

• Availability of healthy food stores

• Presence and hours of liquor stores/bars

Moderating Factors of Sleep Health Determinants

1. Material resources

2. Psychosocial resources

3. Biological attributes

Sleep and Public Health

[IMAGE CONCEPTUAL FRAMEWORK p.36]

Neighbourhood and Housing Determinants of Sleep Health

[IMAGE p.42]

Intervention to Improve Sleep

• Soundproofing

  • Ex: Norway

• Policy to manage light pollution

  • Ex: Europe

• Air traffic hours and routing

• Improvement of public transit

• School hours

• Neighborhood revitalization through investments

Unintended Consequences of Interventions

• More light so people feel more safe → exacerbate light pollution

• Neighborhood revitalization: maybe people with more money come there, so more healthy, so better sleep (not intended population)

Study Examples

• Sleep quality improves after a slum house upgrade

  • Improved sleep quality

  • Decreased sleep latency

  • Increased sleep duration

  • Improved sleep efficiency

  • Fewer sleep disturbances

  • Less daytime dysfunction

  • Better sleep quality

  • Less stress

  • Better quality of life

  • [IMAGE CONCEPTUAL FRAMEWORK p.66]

• The impact of home safety on sleep in a Latin American country

  • Home safety was the most important predictor of sleep quality

  • Feeling unsafe in home = shorter sleep duration

• Neighborhood factors as predictors of poor sleep in Hispanic community

  • Violent neighborhoods → higher prevalence of short sleep and poor sleep

  • Unsafe neighborhoods → higher prevalence of short sleep and poor sleep (more significant)

Sleep Health Disparities

• Sleep health disparities: differences in one or more dimensions of sleep health on a consistent basis that adversely affect designated disadvantaged populations

  • Disparities exist in sleep health related in part to modifiable factors for adequate sleep quality and quantity such as having a safe, predictable place for sleep ad being able to devote adequate time to obtain sufficient sleep