14. Sleep Flashcards
(43 cards)
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)
