Week 3 Flashcards
What is sleep?
An altered state of consciousness characterised by:
Immobility
Reduced responsiveness
Fast reversibility to the awake state
Recurrence (fairly reliable on a 24hr cycle)
What is a hypnogram?
Used to show the pattern of a night of sleep
What does a typical hypnogram trace look like?
Start awake, progress to light sleep (N1) then deeper sleep brain slowing down (N2) then into deep sleep (N3) (hard to wake someone from deep sleep) then drift between N2 and REM
What is REM sleep?
Rapid eye movement
Brain more active but muscles still immobile
Most likely to dream during this stage
What is meant by sleep latency?
Period between trying to fall asleep and actually falling asleep
What is meant by sleep duration?
How long in total one sleeps for
What is meant by sleep disturbance?
How much time is spent awake during the night
What is meant by sleep efficiency?
The proportion of time spent in bed that is actually asleep
What is meant by sleep perceived quality?
Someone’s perception (subjective) of how they slept
What is meant by sleep daytime dysfunction?
How sleepy someone feels the next day
How can recall questionnaires be used to measure sleep?
Retrospective self-reported summary of sleep parameters (e.g. Pittsburg sleep quality index)
How can a diary be used to measure sleep?
Prospective daily self reported measures/record of sleep parameters
How can polysomnography be used to measure sleep?
Physiological measurements (e.g. Brain waves, eye/muscle activity, heart rhythm)
How can actigraphy be used to measure sleep?
Wrist worn sensor of gross motor activity
What are the characteristics of sleep hygiene?
Regular hours Restful sleep environment Ensure comfortable bed Exercise regularly Consume less caffeine Don't over indulge on food/alcohol Don't smoke Try to relax before bed
What did a cross sectional survey of sleep of 1506 people in the US show?
Less active people have greater frequency of negative states e.g. disturbance/latency
Exercise associated with better sleep
What are possible confounders of sleep quality?
Health status - someone healthy more likely to both sleep and exercise better
Lifestyle - people who exercise more are likely to have other healthy lifestyle factors
Stress - high stress often related to poor sleep and a feeling of not having time to exercise
Daylight - people who exercise more may get more outside time - impact of controlling sleep cycle
What did meta analysis show about the effects of exercise on sleep?
Acute exercise has beneficial impacts on many objective indices of sleep, however these effects are small
Ceiling effect though - most likely done on already healthy sleepers so not much room for improvement so only small effects
What is suggested about night time exercise and sleep?
Increased HR during first few hours of sleep then steadies
Didn’t actually impact sleep efficiency, same as control
What is the circadian rhythm?
Internal biological clock
Controls appetite, sleep, body temperature and more
What are the sleep chronotypes?
Refers to individual sleep cycle propensity
Dictated by circadian rhythm
Morning chronotype - advanced sleep cycle (larks)
Evening chronotype - delayed sleep cycle (owls)
Intermediate chronotype - flexible
What is the DSM-V for insomnia?
Difficulty initiating or maintaining sleep or suffering from non restorative sleep for 3 or more days a week for at least 1 month.
Causing distress e.g. sleepiness, poor concentration, low mood or impaired social, occupational or other functioning.
What are the personal and societal costs of insomnia?
Lower quality of life Lower productivity Higher absenteeism Accident rates Healthcare costs
What were the results of the walking trial on 41 adults with chronic insomnia?
Home based walking - 30 min 5d/w - 67% reduction in insomnia symptoms
Exercise also led to a reduction in depression/anxiety
