Getting Sufficient Sleep May Help Reduce Weight Gain

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Posting this since people with autoimmune disorders often have trouble with

sleep.

http://www.medscape.com/viewarticle/495410

Dec. 7, 2004 - Sleep deprivation alters hormones and increases appetite,

according to the results of a brief randomized study published in the Dec. 7

issue

of the ls of Internal Medicine. The editorialists suggest that getting

enough sleep may help reduce weight gain.

" Total sleep deprivation in rodents and in humans has been associated with

hyperphagia, " write Karine Spiegel, PhD, from the University of Chicago in

Illinois,

and colleagues. " Over the past 40 years, self-reported sleep duration in the

United States has decreased by almost two hours. "

In this two-period, two-condition crossover clinical study, 12 healthy men

were randomized to two days of sleep restriction (four hours per night) and

two

days of sleep extension under controlled conditions of energy intake and

physical activity. Mean age was 22 ± 2 years, and mean body mass index (BMI)

was

23.6 ± 2.0 kg/m2. Outcomes were daytime profiles of plasma leptin and

ghrelin levels and subjective ratings of hunger and appetite.

During sleep restriction, there was an 18% decrease in the anorexigenic

hormone leptin (P = .04), 28% increase in the orexigenic factor ghrelin (P <

0.40),

24% increase in hunger (P < .01), and 23% increase in appetite (P = .01),

especially for energy-dense foods with high carbohydrate content (increase,

33%

to 45%; P = .02).

Study limitations were small sample size, lack of generalizability, and lack

of measurement of energy expenditure.

" Short sleep duration in young, healthy men is associated with decreased

leptin levels, increased ghrelin levels, and increased hunger and appetite, "

the

authors write. " Additional studies should examine the possible role of

chronic sleep curtailment as a previously unrecognized risk factor for

obesity. "

The National Institutes of Health, the University of Chicago, the European

Sleep Research Society, and the Belgian Fonde de la Recherche Scientifique

Medicale

supported this study. The authors report no potential financial conflicts of

interest.

In an accompanying editorial, S. Flier, MD, and K. Elmquist,

DVM, PhD, from Beth Israel Deaconess Medical Center in Boston,

Massachusetts,

wonder if controlled studies should be designed to measure the effect of

sleep-promoting interventions on appetite and body weight. However, they

note

that this study does not prove a cause-effect relationship between the

hormone levels and hunger and dietary intake. Other factors, such as

cortisol or

orexin, may affect sleep and body weight regulation.

" If the findings prove to be reproducible and generalizable, and the

hormonal changes of leptin and ghrelin due to sleep curtailment cause

changes in food

intake over time, we might add sleep duration to the environmental factors

that are prevalent in our society and that contribute to weight gain and

obesity, "

the authors write. " Although recommendations to get both a better night's

sleep and more exercise might superficially seem to be at odds with each

other

from the perspective of energy expenditure and energy balance, these simple

goals may well become a part of our future approach to combating obesity. "

Ann Intern Med. 2004;141:846-850, 885-886

Clinical Context

In animal models, sleep deprivation has been shown to lead to marked

hyperphagia. In humans, circulating leptin and ghrelin hormones decrease and

increase

in response to energy shortage or surplus. Ghrelin is produced by the

stomach and stimulates appetite in response to hunger, while leptin is

produced by

adipocytes and is anorexigenic, suppressing appetite in response to satiety

and energy excess. Both are peripheral signals that contribute to the

hypothalamic

appetite regulation centers. For example, three days of underfeeding in

healthy lean human subjects has been reported to result in a 22% decrease in

leptin

levels. Both hormones are believed to be active in energy regulation.

In the past 40 years, according to the authors, sleep loss due to voluntary

curtailment of time in bed has increased. Self-reported sleep duration in

the

U.S. decreased by one to two hours for the second half of the 20th century.

The proportion of young adults sleeping 8 to 8.9 hours per night has

decreased

from 41% in 1960 to 23.5% in 2001 to 2002. During this time, the incidence

of obesity has nearly doubled. The authors postulated that sleep curtailment

in humans may be a risk factor for obesity. They conducted studies on 12

healthy male volunteers to examine the effect of two days of sleep

curtailment

on appetite and hunger and the two hormones linked to appetite control.

Study Highlights

List of 15 items

.. Volunteers were 12 healthy males with a mean age of 22 years, mean BMI of

23.6 kg/m², within 10% of ideal body weight, who did not smoke or take

medications.

They had regular nocturnal time in bed of 7 to 9 hours.

.. Exclusion criterion was travel across time zones within 4 weeks of the

study.

.. Participants had a standard sleep pattern of 11 PM to 7 AM in bed with no

more than 30 minutes of deviation for one week before the study. Naps were

not

allowed.

.. 6 men were randomized to receive sleep curtailment for 2 days followed by

sleep extension for 2 days 6 weeks later, and 6 men were randomized to

receive

the same interventions in reverse order.

.. Sleep curtailment consisted of 4 hours spent in bed (1 to 5 AM) and sleep

extension (10 PM to 8 AM) consisted of 10 hours spent in bed at the research

unit.

.. Blood samples were obtained every 20 minutes from 8 AM to 9 PM after two

days of the interventions for hormone levels. After the second night,

participants

were fed only by intravenous glucose at 5 g/kg body weight for 24 hours to

avoid meal-related fluctuations of hunger and appetite.

.. Volunteers were assessed for hunger and appetite for specific foods using

(1) a visual analog scale at 10 cm, by asking the question " How hungry do

you

feel right now? " and (2) how much they would enjoy 7 different food groups

consisting of sweets, salty foods, starchy foods, fruits, juices and

vegetables,

proteins (meat, fish, eggs), and dairy products.

.. Total sleep time was 9 hours 8 minutes for the extended sleep intervention

and 3 hours 53 minutes for the sleep curtailment intervention.

.. Mean leptin levels were 18% lower for those spending 4 hours compared with

those spending 10 hours in bed (2.1 vs 2.6 ng/mL; P < .01).

.. Ghrelin levels were 28% higher for the sleep-restricted compared with the

sleep-extended group (3.3 vs 2.8 ng/mL; P =.04).

.. The ratio of orexigenic ghrelin compared with anorexic leptin increased by

71% (CI, 7% to 135%) for the group with 4 vs 10 hours in bed.

.. Sleep restriction compared with sleep extension was associated with a 24%

increase in hunger ratings on the visual analog scale (P < .01) and a 23%

increase

in appetite for all food categories combined (P = .01).

.. The appetite increase for the sleep-restricted group was greatest for

energy-dense foods compared with the sleep-extended group (for sweets, salty

and

starchy foods, the increase was 33% to 45%; P = .06).

.. The increased appetite for fruits and vegetables was less consistent for

the sleep-restricted group and appetite for protein foods was unaffected by

sleep

duration.

.. The increase in hunger was proportionate to the increase in ghrelin to

leptin ratio (r = 0.87), and almost 70% of the variance in increased hunger

was

attributable to this ratio.

list end

Pearls for Practice

List of 2 items

.. Ghrelin is an appetite stimulant while leptin is an anorexic hormone

associated with regulation of appetite and hunger in humans.

.. In young healthy men, short sleep duration is associated with decreased

leptin, increased ghrelin, and increased hunger and appetite.

list end

Yanosz Descouedresz

Email:

yanosz@...

On :

yanoszd

I sometimes pity people who

have never felt just cause

to share the bond between two souls,

one with hands, and one with paws.