Epidemiology of Physical Activity and Ovarian Function
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Female athletes often experience changes in their menstrual cycles and generally have decreased levels of the ovarian hormones, estrogen and progesterone. Because lifetime exposure to ovarian hormones is thought to increase the risk of breast cancer, it is reasonable to hypothesize that the hormonal and menstrual cycle changes associated with exercise could reduce the risk of breast cancer. However, the extent to which these changes occur with more moderate levels of recreational and occupational activity typically seen in the population at large is not known. This proposal is for a study of the influence of self-reported physical activity on reproductive hormonal milieu, using available data from the Semiconductor Health Study (SHS). Briefly, the SHS was a large study of adverse reproductive outcomes among workers in the silicon wafer manufacturing plants. One component of the SHS followed a sample of 402 ethnically diverse women for up to six menstrual cycles. The women were interviewed at baseline and then completed daily menstrual diaries and collected daily urine specimens, which were used to measure daily levels of reproductive hormones.
 
 
 
 The basic objective of this grant is to further understand the potential role that physical activity, a modifiable behavior, may have on the development of breast cancer. Although we will not directly examine the relationship of physical activity to breast cancer, we will evaluate whether changes in ovarian function occur in the general population in association with such activity. If we find alterations in reproductive hormonal levels in women not engaged in athletic training, this will give additional impetus to public health strategies aimed at promoting physical activity as a preventive measure against breast cancer. 
 
 
 
 The proposed study is innovative in two respects. First, the SHS itself developed and implemented several innovative methodologies, such as the collection of daily urine samples in a large-scale epidemiological study. Secondly, by utilizing existing data, it allows for a cost efficient, but methodologically sophisticated investigation of physical activity and ovarian function. In addition, the project is multidisciplinary, bringing together the expertise and perspectives of exercise physiology, physical activity epidemiology, reproductive epidemiology, reproductive endocrinology, and occupational health and medicine. 
 
 
 
 Finally, the project has a potential for translational impact in that it could provide additional impetus for the development of public health strategies aimed at promoting regular participation in physical activity. Although this proposed study will not directly benefit the many women who have already developed breast cancer, it may benefit their daughters, their sisters, their friends and the community at large by giving further motivation on both the individual and community level for adoption of an active lifestyle.