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

Abstract

This study will test whether a program of moderate aerobic exercise that is combined with a moderate level of dietary restriction will result in significant decreases in two biomarkers of breast cancer, circulating estrogens and IGF-I. We will also test whether this type of diet/exercise program will produce significant reductions in the peripheral production of estrone by adipose tissue through its impact on the reduction of fat mass. Lastly, validation studies for a novel method of assessing energy status will be performed. To date we have completed our first year of the three year study protocol. Our cohort for Year 1 consisted of 20 women (25-25 yrs) divided into height (26-30 kg/m(2)) and low BMI (21-15 kg/m(3)) exercise groups. Aerobic exercise training was 4 times per week for four consecutive menstrual cycles at 77+/- 3% of maximum heart rate for 40-60 minutes, resulting in an average of 22% increase in aerobic capacity as defined by VO(2) max (P< 0.05 pre vs post). Dietary intake was successfully reduced using the food exchange system (Low BMI = 1889 +/- 354 to 1214 +/_ 239 kcals; High BMI = 2125 +/_ 287 to 1450 +/_ 264 kcals). The combination of moderate exercise and diet produced significant weight loss in both groups (Low BMI - X%; High BMI - X% P<0.05). Significant changes in body composition occurred in both groups (Low BMI 32 +/_ 4% to 25 +/- 8 %; High BMI 39 +/- 5 to 32 +/- 6; P<0.05). As expected, menstrual cycle length in these reproductively mature women did not change significantly with training and weight loss. We are currently conducting biochemical determinations of urinary estrone-3 glucuronide and pregnanediol-3 glucuronide, LH, and PSH, and serum IGF-1, Insulin, T3, Leptin, IGFbp-1, estrone and estradiol. Data reduction and analyses are being completed for dietary intake, energy expenditure, testing metabolic rate. We will begin recruiting for one Year 2 cohort in December, 2002.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2002
Accession Number
ADA411298

Entities

People

  • Nancy I. Williams

Organizations

  • Pennsylvania State University

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Blood
  • Body Composition
  • Body Weight
  • Breast Cancer
  • Department Of Defense
  • Digestive System Processes
  • Diseases And Disorders
  • Eating Disorders
  • Electronic Mail
  • Estrogens
  • Heart Rate
  • Hormones
  • Medical Personnel
  • Menstrual Cycle
  • Neoplasms
  • Recruiting
  • Training

Readers

  • Exercise and Sports Science.
  • Molecular and genetic basis of cancer.