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Overnight Weight Loss and Sleep Structure (weightsleep)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified July 2009 by Associacao Fundo de Incentivo a Psicofarmcologia.
Recruitment status was:  Recruiting
Fundação de Amparo à Pesquisa do Estado de São Paulo
Information provided by:
Associacao Fundo de Incentivo a Psicofarmcologia Identifier:
First received: June 4, 2009
Last updated: July 31, 2009
Last verified: July 2009

The objectives of the present study are:

  1. to evaluate if overnight weight loss is dependent on sleep structure assessed by polysomnography;
  2. to compare weight loss rate during sleep and awake rest;
  3. to compare night weight loss profile of normal and obese volunteers.


Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Overnight Weight Loss, Sleep Structure and the Endocrine System

Resource links provided by NLM:

Further study details as provided by Associacao Fundo de Incentivo a Psicofarmcologia:

Primary Outcome Measures:
  • Adaptation polysomnography (first night) followed by experimental polysomnography with continuous body weight register (second night) [ Time Frame: 8 hours (first night), 8 hours (second night) ]

Secondary Outcome Measures:
  • Pletysmography [ Time Frame: 1 hour (before second night), 1 hour (after second night), 1 hour (after daytime) ]
  • Actigraphy (nighttime, daytime) [ Time Frame: 24 hours (second night, daytime following second night) ]
  • Skin temperature plot [ Time Frame: 8 hours (second night), 8 hours (daytime following second night) ]
  • Daytime continuous weight register [ Time Frame: 8 hours (daytime period following second night) ]

Estimated Enrollment: 60
Study Start Date: September 2007
Estimated Study Completion Date: May 2010
Estimated Primary Completion Date: January 2010 (Final data collection date for primary outcome measure)
Normal volunteers
Volunteers, body mass index 17 to 25
Obese volunteers
Volunteers body mass index higher than 30

Detailed Description:

Weight loss can be caused by loss of body mass due to metabolism and by water loss as insensible water loss, sweating, or excretion in feces and urine. Eighty-three percent of the total weight loss is due to insensible water loss from airways and skin. Water loss rate varies according to changes in activity and ambient temperature and humidity. Although weight loss during sleep is a well-known phenomenon, there are no studies relating it to sleep structure or any other functions during the distinct sleep stages, particularly SWS and REM sleep. There is evidence suggesting a homeostatic mechanism for weight control in animal models and humans. This mechanism is thought to be dependent on energy intake, energy expenditure, and environmental conditions. The literature suggests that sleep is important for weight homeostasis on a long term since sleep shortage is associated with overweight status, but overnight weight variation had not yet been studied. Considering these facts, we hypothesized that the overnight weight loss rate is not uniform throughout the sleep period. We also intend to compare weight loss rate during sleep and awake rest.

Intervention: Normal and obese volunteers will undergo whole night polysomnography with continuous body weight and temperature register after an adaptation night. After that, volunteers will remain awake resting in bed during the following day for continuous weight and temperature register.


Ages Eligible for Study:   21 Years to 35 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Normal and obese volunteers

Inclusion Criteria:

  • normal and obese volunteers

Exclusion Criteria:

  • serious medical or neurological condition
  Contacts and Locations
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Please refer to this study by its identifier: NCT00915642

Contact: Walter Moraes, MD, PhD 55-11-5573-9238
Contact: Marco Tulio Mello, PhD 55-5572-0177

Instituto do Sono / Associacao Fundo de Incentivo a Psicofarmacologia Recruiting
Sao Paulo, Brazil, 04020-060
Contact: Walter Moraes, MD, PhD    55-11-5573-9238   
Contact: Marco Tulio Mello, PhD    55-11-5572-0177   
Principal Investigator: Sergio Tufik, MD, PhD         
Sub-Investigator: Marco Tulio Mello, PhD         
Sponsors and Collaborators
Associacao Fundo de Incentivo a Psicofarmcologia
Fundação de Amparo à Pesquisa do Estado de São Paulo
Principal Investigator: Walter Moraes, MD PhD AFIP / UNIFESP
Study Director: Marco Tulio Mello, PhD AFIP / UNIFESP
Study Chair: Sergio Tufik, MD, PhD AFIP/ UNIFESP
  More Information

Responsible Party: Walter Andre dos Santos Moraes, AFIP Identifier: NCT00915642     History of Changes
Other Study ID Numbers: CEP1516/07
Study First Received: June 4, 2009
Last Updated: July 31, 2009

Keywords provided by Associacao Fundo de Incentivo a Psicofarmcologia:
Weight loss rate

Additional relevant MeSH terms:
Weight Loss
Body Weight Changes
Body Weight
Signs and Symptoms processed this record on April 25, 2017