Role of Oxidative Stress in the Menstrual Cycle Focus of Study

BUFFALO, N.Y. -- Researchers at the University at Buffalo are conducting the first comprehensive study of the relationship between hormonal changes in the menstrual cycle and cellular oxidative stress, thought to be an important factor in female infertility.

The longitudinal study of the potential effects of the hormones estrogen and progesterone on oxidative stress biomarkers will involve 275 women in Western New York between the ages of 18 and 44.

Results of the research, funded by a $3.2 million, two-year grant from the National Institute of Child Health and Human Development, are expected to provide new information on the relationship between hormone levels and several markers of oxidative stress and how this relationship is influenced by antioxidant levels. Oxidative stress is caused by highly toxic, highly reactive oxygen molecules called free radicals, which can damage tissues if not neutralized by antioxidants.

"These findings may help us to better understand the interplay of these factors and ultimately aid in our understanding of the determinants of infertility," said Jean Wactawski-Wende, Ph.D., research associate professor of social and preventive medicine in the UB School of Public Health and Health Professions and principal investigator on the study.

"Studies of both humans and animals have suggested that oxidative stress may be implicated in the risk of infertility in both males and females," she said, "but we know very little about how oxidative stress is influenced by both circulating hormones and by antioxidant intake.

"We think the ways oxidative stress may influence female fertility include its potential impact on the growth of egg follicles in the ovary, its role in the development of endometriosis and its possible regulation of blood vessel formation in the endometrium," said Wactawski-Wende. "However, these potential mechanisms are not well understood.

"We know that micronutrients in the diet such as vitamins A, C and E, as well as antioxidant enzymes, are able to neutralize oxygen free radicals and inhibit oxidative stress," she said.

"Understanding of the role of these therapies in reducing the risk of infertility has been hindered by the lack of research on the interrelation of these antioxidants with oxidative stress levels across hormonal changes during the menstrual cycle."

To collect this information, researchers will take samples of blood and urine from study participants at eight key points during two consecutive menstrual cycles to measure variations in several markers of oxidative stress at the times of greatest hormonal variation. They will also determine the relationship between levels of estrogen and progesterone and measures of oxidative stress at those key points.

To examine the potential influence of external factors on oxidative stress and hormone levels, investigators will collect information on intake of prescription and non prescriptions drugs and vitamin and mineral supplements, cigarette smoking, alcohol consumption, diet, exercise, stress levels and concentrations of vitamins A, C and E in blood serum.

Co-investigators on the study are Maurizio Trevisan, M.D., professor of social and preventive medicine and interim dean of the UB School of Public Health and Health Professions, and Richard W. Browne, Ph.D., assistant professor of clinical laboratory sciences in the UB School of Medicine and Biomedical Sciences.