April 18, 2006
Markers Inherited, Raise Heart Disease, Diabetes Risk
CHICAGO—Menstrual irregularity and unhealthy metabolic traits associated with polycystic ovary syndrome (PCOS) are inherited and persist with age, putting women with PCOS at a high risk for cardiovascular disease and type 2 diabetes.
That finding is reported in a new study published April 17 in the early online edition of the Proceedings of the National Academy of Sciences (www.pnas.org).
“There have been few studies looking at the long-term consequences of PCOS. Results of our study strongly suggest that metabolic problems will continue as women with PCOS age,” said senior author Andrea E. Dunaif, MD, Charles F. Kettering Professor of Endocrinology at Northwestern University’s Feinberg School of Medicine.
Dr. Dunaif is also professor of medicine and chief of endocrinology, metabolism, and molecular medicine at the Feinberg School and president of The Endocrine Society.
PCOS is a common problem affecting about 7 percent of young adult women. Women with this disorder have irregular menstrual cycles and elevated levels of male hormones, or androgens, which may result in excessive facial hair growth and acne.
PCOS is frequently also associated with insulin resistance, and the syndrome is a leading cause of type 2 diabetes in adolescent and young adult women. Another negative health feature of PCOS is abnormal lipid levels, but the reasons are controversial. Insulin resistance, type 2 diabetes, increased low-density lipoprotein (LDL) levels, and metabolic syndrome all increase risk for heart disease.
Studies of women with PCOS, by definition, have been limited to women in their reproductive years; therefore, little is known about their health as they age. The long-term health consequences of PCOS are of considerable importance because many of these women have risk factors that confer substantially increased risk for developing cardiovascular disease and other problems.
It is well documented that PCOS runs in families. Though limited, studies of mothers of women with PCOS have shown increased androgen levels, insulin resistance, and glucose intolerance, suggesting that these traits are inherited.
Dr. Dunaif and colleagues Susan Sam, MD, instructor in medicine at the Feinberg School, and Richard S. Legro, MD, of Pennsylvania State University College of Medicine, Hershey, tested their hypothesis that abnormal lipid levels are inherited in families of women with PCOS and assessed the impact of age on reproductive and metabolic characteristics.
The researchers studied 215 non-Hispanic white mothers of women with PCOS and a control group of 62 women of comparable age, weight, and ethnicity, drawn from the National Health and Nutrition Examination Survey (NHANES) III.
The study group was limited to non-Hispanic white women because of the potential confounding effects of ethnicity on insulin sensitivity and lipid levels. All participants were asked to complete a questionnaire on their reproductive history, exercise habits, tobacco use, and alcohol intake.
In investigating lipid levels, the researchers found that mothers of women with PCOS had elevated total and LDL cholesterol levels, but triglycerides and high-density lipoprotein (HDL) cholesterol levels did not differ between the groups. The mothers had markers of insulin resistance. They also had an increased prevalence of the metabolic syndrome compared with nationwide prevalence in normal women of similar age.