Environmental Factor, December 2005, National Institute of Environmental Health Sciences
Autoimmune Disorders: an Epidemiological Challenge
By Colleen Chandler
Glinda Cooper, an epidemiologist in the Environmental Diseases and Medicine Branch, is leaving NIEHS in mid January to accept a position as senior epidemiologist for the Environmental Protection Agency in Washington, D.C. Cooper will be assigned to the Integrated Risk Information System, part of the National Center for Environmental Assessment.
At NIEHS, she focused on autoimmune disorders from an epidemiological perspective. Not long after coming to NIEHS to study women's health in 1993, Copper became interested in autoimmune disorders, an area that she describes as "clearly under researched" and that disproportionately affects women. Epidemiologists not only look at clusters and infectious disease, but at the distribution of chronic diseases as well.
Autoimmune disorders are - as physicians already know - more challenging to diagnose, generating a constellation of symptoms. They are challenging from a research perspective because there are no distinctive pathology reports or diagnostic codes for a patient database. Diagnosis does not require a hospital stay, so there are no hospital records from which to cull potential research subjects, and the diagnostic criteria for research subjects is different than that for clinical treatment.
NIH estimates that 5 to 8 percent of the U.S. population suffers from autoimmune disorders, however, there has been a disproportionately small amount of edpidemiologic research on autoimmune disorders. Cooper's research interests span genetic, hormonal, and Glinda Cooper environmental influences on diseases that disproportionately affect women. Much of her research focused on autoimmune diseases, particularly systemic lupus erythematosus, or SLE. A central part of her research is The Carolina Lupus Study, the first population-based case-control study in the United States that looked at hormonal and occupational risk factors for SLE. According the information on the NIEHS website, the study was designed to explore environmental influences and the interaction between specific environmental exposures and susceptibility genes, to the etiology of SLE. The study found an absence of estrogen-related effects on risk, but a strong connection to occupational silica dust exposure.
Cooper is expanding her research to include other autoimmune diseases, such as systemic vasculitis, systemsclerosis and rheumatoid arthritis, looking at demographic, genetic, and environmental risk factors to learn more about the pathogenesis of autoimmune diseases. Researchers no longer believe there is a singe mechanism at work in autoimmune disorders. Existing research suggests some people are prone to specific families of autoimmune disorders while others are prone to specific autoimmune diseases within a specific family of autoimmune diseases, Cooper said.
However, Cooper did not abandon her initial research interests - ovarian function and the cyclical production of estrogen and progesterone during reproductive years and the timing of ovarian failure or menopause. Ovarian function influences fertility, and specific menstrual characteristics such as cycle length or variability may directly or indirectly affect the risk of developing hormonally-mediated diseases. As part of her research in this area, she tapped into data from the National Health and Nutrition Examination Surveys and the National Health Interview Survey, as well as menstrual diaries completed between 1930-1960 to examine associations between demographic, medic al, and lifestyle characteristics and timing of natural menopause. This research will continue to look at effects of potential environmental endocrine disruptors on ovarian function.