An Innovative Assessment of Endogenous Estrogen Activity in Persons with Different Habits of Exercise
Abstract
Exercise has been associated with a reduced risk of breast cancer. Evidence exists that women exercising have lower estrogen levels than sedentary women. These lower estrogen levels appear to be the mechanism behind their reduced breast cancer risk. Previous studies have included athletes with high exercise levels, and estrogen measurements have been based on a few serum samples taken at different times during a menstrual cycle. We are studying 60 sets of genetically identical female twins who are discordant with regard to moderate exercise levels. Estradiol is being measured on a daily basis by use of salivary samples collected during a complete menstrual cycle. The first year has included development of procedures, questionnaires, and enrollment of eligible pairs. Screening interviews have been conducted with 135 pairs. Sixteen out of 20 pairs of eligible twins have agreed to participate and 10 of these pairs have completed the requirements of the study. Although fewer eligible pairs were identified than expected, additional twins will be available from the second phase of the California Twin Program. In Year 2, we will continue to screen and enroll twins for participation, initiate data entry of questionnaires, and complete laboratory hormonal assays.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1998
- Accession Number
- ADA368406
Entities
People
- Ann S Hamilton
Organizations
- University of Southern California