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Effect of Bright Light on Sex Hormones and Ovulation in Humans

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00327366
Recruitment Status : Completed
First Posted : May 18, 2006
Last Update Posted : October 19, 2009
Information provided by:
Russian Academy of Medical Sciences

Brief Summary:
The study investigated whether bright artificial light may influence menstrual cycle and ovulation conclusively, and what underlying hormonal changes for this effect are.

Condition or disease Intervention/treatment Phase
Anovulation Procedure: Light therapy Not Applicable

Detailed Description:
Several studies have shown a shortening of the menstrual cycle following light therapy in women with abnormally long menstrual cycles or with winter depression, which suggests that bright light may influence sex hormones and ovulation. The study was designed to investigate this possibility. Twenty-two women with slightly lengthened menstrual cycles and without clinically evident endocrine abnormalities completed a study lasting for two menstrual cycles separated by an off-protocol episode of at least 1 menstrual cycle. Bright light therapy was administered for a week at home during one experimental cycle, and dim light during another cycle (placebo-controlled, crossover, counter-balanced order). Daytime blood sampling and ultrasound scan were performed before and after a week of light therapy, on the ~7th and 14th days after menstruation onset. Ultrasound examination was repeated further to document ovulation. Serum was assayed for thyroid-stimulating hormone, prolactin, luteinizing hormone, follicle-stimulating hormone, and estradiol. The preliminary results were reported at the SLTBR meeting in June, 2005.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 27 participants
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Basic Science
Study Start Date : September 2003
Actual Study Completion Date : April 2006

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years to 40 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 19-40 years
  • Mean menstrual cycle 28-38 days
  • Good general health
  • Generally normal sleep-wake regimen
  • Motivated for free participation

Exclusion Criteria:

  • Low cooperation
  • Medications known to interfere with hormone release
  • Clinically evident endocrine abnormalities including the signs of
  • Hyperandrogenism
  • Travel over several time zones during two months prior the study

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00327366

Sponsors and Collaborators
Russian Academy of Medical Sciences
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Principal Investigator: Konstantin V. Danilenko, MD Institute of Internal Medicine SB RAMS

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Responsible Party: Outside In Identifier: NCT00327366    
Other Study ID Numbers: M-s3
First Posted: May 18, 2006    Key Record Dates
Last Update Posted: October 19, 2009
Last Verified: October 2009
Keywords provided by Russian Academy of Medical Sciences:
Menstrual Cycle
Light Therapy
Sex Hormones
Additional relevant MeSH terms:
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Ovarian Diseases
Adnexal Diseases
Genital Diseases, Female
Gonadal Disorders
Endocrine System Diseases