Effects of Gynecological Age on LH Sensitivity to Energy Availability

Infertility Clinical Trial

Official title:

Dietary Energy Requirements in Physically Active Men and Women, Objective 4B: Effects of Gynecological Age on LH Sensitivity to Energy Availability

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00260286
• Other study ID #: Excalibur X
• Secondary ID: DAMD_17-95-1-505
• Status: Completed
• Phase: N/A
• First received: November 30, 2005
• Last updated: December 2, 2005
• Start date: August 2001
• Est. completion date: May 2004

Study information

• Verified date: November 2005
• Source: Ohio University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

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

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 18
• Est. completion date: May 2004
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 34 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Prevention

Related Conditions & MeSH terms

• Amenorrhea
• Anovulation
• Infertility
• Starvation

Intervention

Behavioral:
• Energy availability

Locations

Country	Name	City	State
United States	Ohio University	Athens	Ohio

Sponsors (2)

Lead Sponsor	Collaborator
Ohio University	Ohio State University

Country where clinical trial is conducted

United States, 

References & Publications (8)

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. — View Citation

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. — View Citation

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. — View Citation

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. — View Citation

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. — View Citation

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. — View Citation

Loucks AB, Verdun M, Heath EM. Low energy availability, not stress of exercise, alters LH pulsatility in exercising women. J Appl Physiol (1985). 1998 Jan;84(1):37-46. — View Citation

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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	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

External Links

•   Click here for more information about this study. Women's Reproductive Health Study