Energy Restriction and Hormones in Premenopausal Women

Menstruation Disturbances Clinical Trial

Official title:

Effects of Moderate Aerobic Exercise Combined With Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05107804
• Other study ID #: 01M0088
• Secondary ID: M01RR010732DAMD
• Status: Completed
• Phase: N/A
• Start date: March 2001
• Est. completion date: November 2006

Study information

• Verified date: October 2021
• Source: Penn State University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

A growing body of epidemiological and biological evidence strongly suggests that physical activity may reduce the risk of breast cancer. Although the mechanism remains unclear, possible links between reduced risk and exercise include favorable alterations in body composition and positive changes in the hormonal milieu. One hormonal biomarker of breast cancer, circulating estrogen, is postulated to be reduced by chronic physical activity, presumably due to disruptive effects of exercise upon menstrual cyclicity, and the potential for loss of body fat with subsequent reductions in the peripheral biosynthesis of circulating estrogens. Although studies have shown that chronic exercise can reduce circulating estrogen, we know little about the magnitude and duration of exposure to an energy deficit required for these changes. Additionally, no studies have addressed the degree to which peripheral production of estrone, versus the ovarian production of estradiol, is altered with exercise that promotes weight/fat loss. A second biomarker of breast cancer, insulin-like growth factor-1 (IGF-1), is presumably increased with exercise but reduced with exercise if energy balance is negative. No prospective studies have addressed whether a moderate aerobic exercise program that results in weight loss will lead to significant changes in IGF-I levels, particularly in individuals of differing initial energy stores.

Metabolic energy availability is an important contributing factor in the development of reproductive cancers. However, current methods for assessing energy availability, which include anthropometric measures, calculations of energy balance, evaluation of various serum and urinary biomarkers are prone to measurement error, not sensitive to alterations in energy availability, and are sometimes affected by disease states. The current project includes the introduction of a novel approach to estimating energy status by measuring metabolic hormones in plasma: insulin, IGF-I, insulin-like growth factor binding protein-3 (IGFBP-3) and leptin.

This study tested whether a program of moderate aerobic exercise that is combined with a moderate level of dietary restriction would result in significant decreases in two biomarkers of breast cancer, circulating estrogens and IGF-I.

Description:

This study used a randomized prospective design (block; 3:1 allocation) to test the effects of a four month (four menstrual cycles) intervention of moderate aerobic exercise (4 times per week, 60 minutes/session) combined with caloric restriction designed to produce a weekly energy deficit of -20%. The aims of the study were: 1) To test the hypothesis that a moderate level of low energy availability created through a combination of exercise and caloric restriction will lower circulating estrogens and IGF-I; 2) To test the hypothesis that exercise-induced decreases in body fat will contribute substantially to the lowering of circulating estrogens changes with training; 3) To validate a novel method of assessing energy status that represents an improvement of existing.

Eumenorrheic, untrained women between 25-40 years (n=47) were randomly assigned to one of two treatments groups: exercise with caloric-restriction (EX+CR; n=36) or light conditioning reference (LC; n=11) groups. To determine treatment effects on circulating estrogens, reproductive function and IGF-I, both serum and urinary levels of hormones were monitored for a control period of 2 months (2 menstrual cycles), i.e., Screening and Baseline, followed the 4 month (4 menstrual cycles: intervention 1-4) experimental period. The exercise/diet intervention began on the first day of the third month (menstrual cycle) and continue for four menstrual cycles thereafter (intervention 1, 2, 3, and 4). A post-study measurement was taken during cycles days 1-7 of the seventh menstrual cycle.

Baseline energy needs were assessed during the baseline cycle. Resting metabolic rate and non-exercise physical activity were added to determine a caloric need for the day. Caloric intake was supervised throughout the entire study, and meals were comprised of 55% carbohydrates, 30% fat, and 15% protein. Exercise training was supervised, and maximal aerobic capacity (VO2max) was calculated. Menstrual status was assessed through analysis of daily urinary metabolites of estrone-1-glucuronide (E1G), pregnanediol glucuronide (PdG), and midcycle luteinizing hormone (LH). Underwater weighing and a digital scale were used to assess body composition, and fasting blood samples were collected to assess metabolic hormones.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 47
• Est. completion date: November 2006
• Est. primary completion date: November 2006
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 25 Years to 40 Years

Eligibility

Inclusion Criteria:

• Weight 50-90 kg

• BMI 18-35 kg/m2

• Nonsmoking

• <1 hour/week of purposeful aerobic exercise for the past 6 months

• Gynecological age =10 years

• Documentation of at least two ovulatory menstrual cycles during screening.

Exclusion Criteria:

• History of serious medical conditions

• Medication use that would alter metabolic hormone levels

• Significant weight loss/gain (±2.3 kg) in the last year

• Current evidence of disordered eating or history of an eating disorder

• Taking exogenous hormonal contraceptives for the past 6 month

• Smoking

Related Conditions & MeSH terms

• Luteal Phase Defect
• Menstruation Disturbances

Intervention

Other:
• Exercise+CR
Exercise with caloric-restriction
• Light Conditioning
Light Conditioning Exercise

Locations

Country	Name	City	State
n/a

Sponsors (4)

Lead Sponsor	Collaborator
Penn State University	National Center for Research Resources (NCRR), National Institutes of Health (NIH), United States Department of Defense

References & Publications (1)

Williams NI, Reed JL, Leidy HJ, Legro RS, De Souza MJ. Estrogen and progesterone exposure is reduced in response to energy deficiency in women aged 25-40 years. Hum Reprod. 2010 Sep;25(9):2328-39. doi: 10.1093/humrep/deq172. Epub 2010 Jul 6. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in estrogen and IGF-1	Change in urine estrone-1-glucuronide (E1G ng/mL) and serum IGF-1 (ng/mL)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in body composition	Change in percent body fat (%)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in body composition	fat mass (kg) and fat free mass (kg)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in reproductive hormones	Change in reproductive hormones sex hormone binding globulin (SHBG nmol/L)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in reproductive hormones	Change in reproductive hormones pregnanediol glucuronide (PdG ng/mL)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in metabolic hormones	Change in metabolic hormones leptin (ng/mL) and insulin-like growth factor binding protein 3 (ng/mL)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in metabolic hormones	Change in metabolic hormone insulin (µIU/mL)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in metabolic hormones	Change in metabolic hormone sex hormone binding globulin (nmol/L)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in metabolic hormones	Change in metabolic hormone total triiodothyronine (ng/dL)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC), and Post Study (days 1-7 last MC)
Secondary	Change in menstrual cycle phase length	Change in follicular phase length (days) and luteal phase length (days)	Baseline Menstrual Cycle (MC) (28 days (d) or the length of 1 MC, intervention 1 (28 d or 1 MC), intervention 2 (28 d or 1 MC), intervention 3 (28 d or 1 MC), intervention 4 (28 d or 1 MC)