Effects of Gynecological Age on LH Sensitivity to Energy Availability - Full Text View

Purpose

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

Condition	Intervention
Anovulation Amenorrhea Infertility Starvation	Behavioral: Energy availability

Study Type:	Interventional
Study Design:	Allocation: Randomized Endpoint Classification: Efficacy Study Intervention Model: Crossover Assignment Masking: 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

Resource links provided by NLM:

MedlinePlus related topics: Diabetes Medicines Infertility

U.S. FDA Resources

Further study details as provided by Ohio University:

Primary Outcome Measures:

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:

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

Estimated Enrollment:	18
Study Start Date:	August 2001
Estimated Study Completion Date:	May 2004

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.

Eligibility

Ages Eligible for Study:	18 Years to 34 Years
Genders Eligible for Study:	Female
Accepts Healthy Volunteers:	Yes

Criteria

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

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00260286

Locations

United States, Ohio
Ohio University
Athens, Ohio, United States, 45701

Sponsors and Collaborators

Ohio University

Ohio State University

Investigators

Principal Investigator:

Anne B Loucks, Ph.D.

Ohio University

More Information

Additional Information:

Click here for more information about this study. Women's Reproductive Health Study This link exits the ClinicalTrials.gov site

Publications:

Loucks AB, Verdun M, Heath EM. Low energy availability, not stress of exercise, alters LH pulsatility in exercising women. J Appl Physiol. 1998 Jan;84(1):37-46.

Loucks AB, Heath EM. Induction of low-T3 syndrome in exercising women occurs at a threshold of energy availability. Am J Physiol. 1994 Mar;266(3 Pt 2):R817-23.

Hilton LK, Loucks AB. Low energy availability, not exercise stress, suppresses the diurnal rhythm of leptin in healthy young women. Am J Physiol Endocrinol Metab. 2000 Jan;278(1):E43-9.

Loucks AB, Callister R. Induction and prevention of low-T3 syndrome in exercising women. Am J Physiol. 1993 May;264(5 Pt 2):R924-30.

Loucks AB, Heath EM. Dietary restriction reduces luteinizing hormone (LH) pulse frequency during waking hours and increases LH pulse amplitude during sleep in young menstruating women. J Clin Endocrinol Metab. 1994 Apr;78(4):910-5.

Loucks AB, Verdun M. Slow restoration of LH pulsatility by refeeding in energetically disrupted women. Am J Physiol. 1998 Oct;275(4 Pt 2):R1218-26.

Loucks AB, Thuma JR. Luteinizing hormone pulsatility is disrupted at a threshold of energy availability in regularly menstruating women. J Clin Endocrinol Metab. 2003 Jan;88(1):297-311.

Ihle R, Loucks AB. Dose-response relationships between energy availability and bone turnover in young exercising women. J Bone Miner Res. 2004 Aug;19(8):1231-40. Epub 2004 Apr 19.

ClinicalTrials.gov Identifier:	NCT00260286 History of Changes
Other Study ID Numbers:	Excalibur X, DAMD_17-95-1-5053,, M01_RR00034
Study First Received:	November 30, 2005
Last Updated:	December 2, 2005
Health Authority:	United States: Institutional Review Board

Keywords provided by Ohio University:

LH pulsatility
energy availability
exercise
diet
gynecological age

Additional relevant MeSH terms:

Amenorrhea
Anovulation
Infertility
Starvation
Menstruation Disturbances
Pathologic Processes
Ovarian Diseases

Adnexal Diseases
Genital Diseases, Female
Gonadal Disorders
Endocrine System Diseases
Genital Diseases, Male
Malnutrition
Nutrition Disorders

ClinicalTrials.gov processed this record on May 16, 2013