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Effects of Gynecological Age on LH Sensitivity to Energy Availability

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ClinicalTrials.gov Identifier: NCT00260286
Recruitment Status : Completed
First Posted : December 1, 2005
Last Update Posted : December 5, 2005
Ohio State University
Information provided by:
Ohio University

Brief Summary:
The purpose of this experiment is to investigate whether the dependence of luteinizing hormone pulsatility on energy availability declines during adolescence.

Condition or disease Intervention/treatment
Anovulation Amenorrhea Infertility Starvation Behavioral: Energy availability

Detailed Description:

The incidence of menstrual disorders declines during adolescence. This has long been attributed to the gradual "maturation" of the hypothalamic-pituitary-ovarian axis, but the mechanism of this "maturation" is not known. Ovarian function critically depends on the pulsatile secretion of gonadotropin-releasing hormone (GnRH) by the hypothalamus and on the consequent and more readily assessed pulsatility of luteinizing hormone (LH) secretion by the pituitary. LH pulsatility has been shown to depend on energy availability, operationally defined as dietary energy intake minus exercise energy expenditure. The effects of energy availability on LH pulsatility are thought to be mediated by certain metabolic substrates and hormones.

Comparison: By manipulating diet and exercise regimens, contrasting energy availability treatments of 10 and 45 kilocalories per kilogram of fat-free mass per day are being administered to adolescents with 5-8 years of gynecological age and to adults with 14-18 years of gynecological age for five days in the early follicular phase of separate menstrual cycles. Effects of low energy availability on LH pulsatility and on selected metabolic substrates and hormones are being measured.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 18 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Dietary Energy Requirements in Physically Active Men and Women, Objective 4B: Effects of Gynecological Age on LH Sensitivity to Energy Availability
Study Start Date : August 2001
Estimated Study Completion Date : May 2004

Primary Outcome Measures :
  1. Differences in 24h LH pulse frequency, 24h LH pulse amplitude and 24h LH mean concentration in blood samples drawn q10' for 24 hours after 5 days of treatment

Secondary Outcome Measures :
  1. Differences in 24h average glucose, beta-hydroxybutyrate, insulin, cortisol, growth hormone, insulin-like growth factor-I, tri-iodothyronine, and leptin concentrations in blood samples drawn q10' for 24 hours after 5 days of treatment

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Ages Eligible for Study:   18 Years to 34 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • 5-8 or 14-18 years of gynecological age
  • menstrual cycles of 26 to 32 days for the previous 3 months
  • luteal phase length >11 days
  • 18-32% body fat

Exclusion Criteria:

  • smoking
  • oral contraceptives
  • hematocrit <35%
  • diet with <35 or >55 kcal/kgFFM/day of energy
  • habitually performing more than 60 minutes/week of aerobic exercise
  • histories or evidence of heart, liver, or kidney disease, diabetes, menstrual or thyroid disorders, pregnancy, lactation, and congenital or acquired orthopedic abnormalities

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 ClinicalTrials.gov identifier (NCT number): NCT00260286

United States, Ohio
Ohio University
Athens, Ohio, United States, 45701
Sponsors and Collaborators
Ohio University
Ohio State University
Principal Investigator: Anne B Loucks, Ph.D. Ohio University

ClinicalTrials.gov Identifier: NCT00260286     History of Changes
Other Study ID Numbers: Excalibur X
M01RR000034 ( U.S. NIH Grant/Contract )
First Posted: December 1, 2005    Key Record Dates
Last Update Posted: December 5, 2005
Last Verified: November 2005

Keywords provided by Ohio University:
LH pulsatility
energy availability
gynecological age

Additional relevant MeSH terms:
Genital Diseases, Male
Genital Diseases, Female
Menstruation Disturbances
Pathologic Processes
Ovarian Diseases
Adnexal Diseases
Gonadal Disorders
Endocrine System Diseases
Nutrition Disorders