14. Sleep Flashcards
Why do we sleep? (4)
- energy conservation
- reduce expenditure -> reduce fuel need? - facilitate learning and memory
- ‘classic’ EEG experiments - cellular repair and restoration
- products of oxidative stress build up - evolutionary protection from predators
- stay still, quiet, out of sight during the night when you’re vulnerable
Sleep requirements
depends on age
- new born most sleep 14-17hrs
- young adult 7-9hrs
variations between people
- more or less may be ok
how much do people actually sleep?
> 60% get less than 7hrs
> 30% get recommended
reasons for low sleep?
low priority
- too busy
sleep apnea (increasing) - common with obesity
consequences of sleep deprivation
- fatigue, lethargy. lack motivation
- moodiness, irritability
- creativity, problem solving
- stress coping
- immune system
- concentration, memory
- motor skills, more accidents
- decision making
- weight gain
- heart disease and insulin resistance
top self reported sleep related difficulties
- concentration
- remembering
- working on hobbies
etc
low sleep requirement gene
DEC2 mutation
- over expression sleep more
- deletion sleep less
(mouse study)
people with DEC2 mutation
under expression / deletion –> require less sleep
- faster metabolism
- leaner
- healthier overall
more “effecient” sleepers (maybe)
sleep cycle graph
Wake
REM
Non-REM
- 4 stages (light -> deep)
Metabolic processes during wake and sleep
wake
- cortisol spike
- catecholamine spike
- insulin secretion
- FA uptake and oxidation
- glycolytic metabolism
sleep
- melatonin spike
- temp drop
- growth hormone spike
- leptin secretion
- glucagon secretion
- mitochondrial biogenesis
Vicious cycle of sleep and obesity
lack of sleep
- decreased motivation
- disrupted metabolism
- hormonal changes
- more time awake to eat
- ** cause obesity
obesity
- sleep apnea and other sleep disorders
- depression and anxiety
- chronic inflammatory state (leads to change in hormones)
- ** cause lack of sleep
Study: weight gain and time spent sleeping
- women over 16 years
started heavier and gained more weight
childhood sleep and adult BMI
1hr reduction in sleep as child
– 50% increased risk of obesity at 32yr
% of people reporting insomnia increased
BMI
leisure time physical activity
sleep and appetite
- 2d with 4hr sleep vs 10hr sleep
lack of sleep increased appetite
- decreased leptin
- increased ghrelin
sleep and food choices
greater % wanted higher fat food choices
- need more energy while awake longer
study
- 23 lean subjects
- controlled for sleep
- list of 80 foods, selected ones they desired
energy conservation during sleep
10% max (small)
E = BMR + thermic effect of food + physical activity
insomniacs and mental health
10x depression
17x anxiety
- diseases cause either insomnia or oversleeping
- ** viscous cycle
why is lack of sleep so detrimental
less time spent in deep restorative sleep
sleep and cognitive recognition and negativity
40% reduced recognition of words
- forgot 50% positive words
- only 20% negative words
negativity
sleep and IR
whole body - 16% decrease
adipose - 30% decrease
study
4days of 4hr sleep vs 8hr sleep
sleep and immune function
more antibodies produced during sleep
study
- hep A shot
- kept wake vs sleep
shift workers
increased incidence of coronary heart disease
daylight savings
1hr sleep huge difference
increased myocardial infarctions
- 7 days following forward (spring)
decreased myocardial infarctions
- 7 days moving back (fall)
OSA
obstructive sleep apnea
- soft palate drops to block airway
- intermittent and repetitive cessation of breathing
- decreased blood O2 during sleep
- fragmented sleep
- decrease REM and slow wave NREM sleep
- viscous cycle
OSA risk factors
obesity
>50% T2D
OSA treatment
CPAP
- continuous positive airway pressure
too much sleep
increased disease risk (chronic scenario)
- usually masks existing diseased
the body’s internal clock
circardian rhythms
- nerve cells hypothalamus
- suprachiasmatic nucleus (SCN)
SCN function
suprachiasmatic nucleus in hypothalamus
- produces melatonin
- pineal gland
- controlled by light
light and sleep
melanopsin receptors in eye sense light
- transmit signal to SCN (suprachiasmatic nucleus)
- prevents pineal gland from producing melatonin
blue light worst
first and second sleep
used to sleep 2 ~4h
- seperated 1-2hr of quiet time
dark room 14hr per day for 4 weeks
- returned to this sleep schedule
napping
20min
- stages 1 and 2
- havent reached deep sleep yet
social jet lag
diff between body’s sleep and life
- work and school
body clock vs social clock
- dependent on chronotype
exercise and sleep
vigorous is best
- physical exhaustion
- morning is better vs evening
foods that help sleep
meats and dairy, complex carbs, cherries
- tryptophan
- increase seritonin ==> increase melatonin
NSRED
nocternal sleep related eating disorder
caffiene
antagonizes adenosine
- 15mins
- 6.5hrs length
alcohol
reduced REM sleep
- shorten latency but reduce quality
smoking
stimulant
withdrawal during sleep
sleep apnea risk factor
weed
reduce chronic pain
- useful with illness
lethargy and lack of motivation
technology
blue light
insomnia treatments
sleep hygeine practices prescriptions - benzodiazepines (valium) - non-benzodiazepine hypnotics (lunesta OTC (zzquil) natural (melatonin)
sex
- men mostly
- prolactin and oxytocin release
