SLEEP AND WEIGHT HOMEOSTASIS.ppt

8/13/2019 SLEEP AND WEIGHT HOMEOSTASIS.ppt

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Walter A. S. Moraes MD, PhD


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Homeostasis - Walter Bradford Cannon, 1932

dynamic equilibrium, short term


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Rheostasis (Mrosovsky, 1990): long term, reactive or

programmed, alterations in reference level


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1. Qualitatively

2. Quantitatively


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Industrialized countries sleep duration reduced to 5-6 hrs per night

5,6% reduction since 1960.

Sleep reduction associated to obesity, type 2 diabetes, increasedoxidative stress, generalized anxiety

(Penev 2007)


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Eating and sleeping are two mutually excluding behaviors thatare time consuming.

Some evidences suggest that sleep control in mammals isintegrated to energy metabolism (Nicolaidis, 2006)


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Orexin Coordinating Arousal and Appetite

(Willie et al. 2001)


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Sleep Duration and Metabolic Rate Depend

on Diet and Body Size

Sleep duration:carnivores>omnivores>herbivores

Metabolic rate inverselyproportional to body mass(Penev 2007)


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1. Relation between leanmass and NREM sleepduration (Shapiro 1987)

2. PSG: patients withhyperthyroidismshow increasedNREM sleep (Dunleavy 1974)

3. Hypothyroidism: lessSWS (Kales 1967)

4. Physical activityassociated toprolonged sleep (Youngstedt2003)

5. Newborns spend mosttime sleeping (Rogers 2006)


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1. Food energy correlateswith subsequent sleepduration. (Nicolaidis 2006)

2. Nutrient injectionpromotes sleepproportional to theenergy generated (Danguir1980)

3. Increased weightassociated to increasedsleep (Jenkins 2006)

4. Food deprivationassociated toprogressive sleepreduction although SWS

may initially increase inanimals with high fatstorages. (Nicolaidis 2006)

5. Sleep duration

correlates withaminoacids availability(Jeinkins 2006)


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1. Amount of nutrientsinfluences duration ofSWS and REM sleep (Lacey1978)

2. Sleep durationdecreases after fourthday of fasting/ REMsleep reduced

progressively/ SWSmay increase initially inobese individuals(Dewasmes 1984)

3. Difficulty to start sleepreduction of SWS andsleep fragmentation inperiods of food

restriction (Karkin 1994)

4. Patients with anorexianervosa have reducedtotal sleep duration,

SWS and REM sleep.Corrected when theygain weight(Lauer 2004)


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1. Total or partial sleepdeprivation in rodentsleads to weight losseven when food intake

is increased (Everson 2004)2. Negative energy

balance correlatesnegatively withthermogenesis (Koban 2005)

3. Sleep deprivationcorrelated with reducedinsulin and leptin. (Everson2004)

4. Sleep deprivationactivates hypothalamicmechanisms leading toincreased food intake.(Koban 2006)

5. Hypocretinergic neuronsrespond to differentcirculating factors(glucose, insulin, leptin,

ghrelin) regulatingalertness and promotingfeeding behavior (Horvath2005)


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1. In humans weight lossis not observed after 3nights of total sleepdeprivation or 5 nights

of partial sleepdeprivation. (Spiegel 2004)

2. Acute sleep deprivationis followed by small

increase in energyexpenditure during thenight (Fraser 1989)

3. Two weeks of partialsleep deprivation do notresult in increasedenergy expenditure (Penev2006)

4. Humans have lessbrown adipose tissueand therefore are more

resistant to catabolism(Penev 2006)


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1. Energy preservation (likehibernation) criticism:reduction in baselinemetabolic rate is not sointense as to compensate

vulnerability.(Penev 2007)

2. Anabolism: restoration andstructural preservation of tissues

1. Sleep deprivation reducesrelease of anabolic hormones:GH, insulin, prolactin,

testosterone (Spiegel 1997)

2. Sleep deprivation increasesrelease of catabolic hormones:glucagon, cortisol,catecholamines. (Leproult 1997)

3. Sleep deprivation activatesgenes related to the response tostress (Cirelli 2006)

4. Sleep promotes synthesis ofmembranes and restoration of

myelin and glia (Cireli 2006)


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Catabolism

Anabolism

Movement

Feeding

Perception

Protein Synthesis

Tissue restoration

Memory storage

ENERGY(fat>carbohydrates)

ENERGY

(carbohydrates>fat)


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If epidemiologists are truly interested instudying the potential role of sleep with regardto health, it is time to move beyond

unvalidated questions and to begin to leverageavailable technologies such as actigraphy tofully characterize sleep exposures including notonly validated measures of sleep duration but

also the type of sleep obtained. (Patel 2009)


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22

17%METABOLISM

(CO2 )

83%

WATER LOSS

INSENSIBLEWATER LOSS

50%AIRWAYS

SWEAT

INHALEDO2

INHALEDVAPOR

METABOLICWATER

50%SKIN

EXCRETION

TEWL


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23(Dittmar et al. 2002)


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SLEEP AND WEIGHT HOMEOSTASIS.ppt