Geographic location within the United States appears to have an impact on the specific symptoms of polycystic ovary syndrome (PCOS) that any one particular woman will develop, according to a new prospective cohort study.
Women in California were more likely to exhibit high levels of testosterone (hyperandrogenism), while women in Alabama with PCOS had more metabolic dysfunction and hirsutism.
And although the women in Alabama were younger and had a higher body mass index (BMI), even after adjusting for these factors, the clinical differences were still present between the geographic locations, the authors said.
“This study suggests there are regional differences in hormonal and metabolic parameters in women with PCOS in California and Alabama, highlighting the impact of differing genetic and environmental modulators on PCOS development,” Katherine VanHise, MD, of Cedars-Sinai Medical Center, Los Angeles, and colleagues wrote in their article, published online in the Journal of Clinical Endocrinology and Metabolism.
Genetic and environmental factors play a role
Prior research has looked at variations in symptoms of PCOS across countries and identified differences in hirsutism and its prevalence, which is greater in Middle Eastern, Mediterranean, and Indian women, noted senior author Margareta D. Pisarska, MD.
And women of some other backgrounds “are at increased risk of developing metabolic syndrome and insulin resistance, including South Asian, African, and Hispanic women, so they are at a greater risk trajectory of developing manifestations later on in life that can ultimately lead to adverse outcomes in overall health,” Dr. Pisarska, director of the division of reproductive endocrinology and infertility in obstetrics and gynecology at Cedars-Sinai, told this news organization.
“We do see regional differences in the diagnosis of PCOS [in the United States] as well as the manifestations of PCOS including high andrenoemia, hirsutism, and metabolic parameters ... and we need to better understand it because, at least in the entire population, weight was not the entire factor contributing to these differences,” she explained.
“So there are definitely environmental factors and possibly genetic factors that we need to take into consideration as we try to study these women and try to help them decrease their risk of metabolic syndrome later in life,” she noted.
Differences not attributable to race either
PCOS is a common endocrine disorder affecting women and female adolescents worldwide. Diagnosis usually requires at least two of the following to be present: ovulatory dysfunction, hyperandrogenism, and/or polycystic ovarian morphology.
Because of the prior work that had identified differences in symptoms among women with PCOS in different countries, the investigators set out to determine if women of the same race would have distinct hormonal and metabolic traits of PCOS in two geographical locations in the United States, suggesting geo-epidemiologic contributors of the disease
They evaluated 889 women at the University of Alabama at Birmingham and 721 at Cedars-Sinai Medical Center. Participants in Birmingham were a mean age of 28 years, had a mean BMI of 33.1 kg/m2, a mean waist-to-hip ratio of 0.8, and a mean hirsute rate of 84.6%. Participants in California were a mean age of 29.5 years, had an average BMI of 30.1 kg/m2, a mean waist-to-hip ratio of 0.9, and a mean hirsute rate of 72.8%.
The study team gathered data on menstrual cycle history, metabolic and hormonal parameters, and demographic data for each participant. They assessed hirsutism based on modified Ferriman-Gallwey scores of four or more. Patients were classified as having hyperandrogenemia if they had elevated androgen values greater than the 95th percentile of all values or androgen values that exceeded laboratory reference ranges.
The findings showed that Alabama women with PCOS had elevated homeostatic model assessment for insulin resistance scores (adjusted beta coefficient, 3.6; P < .001) and were more likely to be hirsute (adjusted odds ratio, 1.8; P < .001) after adjustment for BMI and age than those in California.
In contrast, women with PCOS in California were more likely to have elevated free testosterone and total testosterone values than women in Alabama (both P < .001). These findings persisted after adjusting for age and BMI.
When stratified by White race, these findings were similar. Notably, BMI and waist-to-hip ratio did not vary between regions in Black women with PCOS, although variations in metabolic dysfunction and androgen profiles persisted.
“This study supports regional differences in hormonal and metabolic parameters in women with PCOS in the United States, highlighting the impact of the environment on PCOS phenotype. Individuals of the same race in different geographical locations of the United States may have differing genetic predispositions for developing diseases such as PCOS,” the researchers said.
“Ongoing research is needed to identify modifiable environmental risk factors for PCOS that may be race and ethnic specific to bring precision medicine to the management of PCOS,” they conclude.
This work was supported in part by grants from the National Institutes of Health and an endowment of the Helping Hand of Los Angeles. Dr. VanHise reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.