PITTSBURGH, Nov. 9 - Young women with polycystic ovary syndrome (PCOS) have metabolic abnormalities, including higher levels of lipids and insulin, that may result in premature atherosclerosis by middle age, according to a University of Pittsburgh study published in the November issue of Arteriosclerosis, Thrombosis and Vascular Biology.
PCOS is one of the most common reproductive disorders, affecting approximately five percent of women in the United States. It is characterized by menstrual irregularities, excessive body hair, infertility, high insulin levels and, often, obesity.
University of Pittsburgh researchers have found that women with PCOS are also at high risk of developing early-onset atherosclerosis, even if they are thin. This connection is due to their lifetime of exposure to higher levels of cardiovascular disease risk factors, such as insulin and LDL, or "bad," cholesterol.
Despite these dangers, PCOS often goes undiagnosed.
"Women with PCOS are usually seen by their doctors for symptoms such as menstrual irregularities or infertility," said Evelyn Talbott, Dr.P.H., associate professor of epidemiology at the University of Pittsburgh's Graduate School of Public Health (GSPH) and principal investigator on the study. "Because it appears that PCOS may cause early onset of atherosclerosis, these women may represent the largest female group at high risk for the development of early onset coronary heart disease. Therefore it is important that physicians recognize these reproductive symptoms as signs of a broader, chronic disorder and treat it accordingly with early lifestyle interventions and/or medications that will reduce cardiovascular disease risks."
In this cross-sectional study, researchers looked for evidence of premature carotid atherosclerosis among women with PCOS who were at least 30 years of age. Participants included 125 PCOS patients and 142 control women. Cases and controls had similar general characteristics such as age and general health. However, women with PCOS had notably higher cardiovascular risk factors.
All study participants underwent ultrasonography of the carotid arteries in the neck to evaluate the presence of carotid plaque and carotid intima-media wall thickness (IMT), two signs of atherosclerosis that predict cardiovascular disease.
Researchers found that 21.6 percent of women with PCOS had plaque in their carotid arteries, compared with only 15.5 percent of women in the control group. Also, PCOS patients age 45 and over had more significant plaque than did the controls. Likewise, IMT was significantly higher among PCOS cases after the age of 45, compared with slight elevations among control women.
Among all participants under the age of 45, IMT was associated with cardiovascular disease risk factors including age, body-mass index, blood pressure, waist-to-hip ratio and triglycerides. In women over 45, however, PCOS was a greater predictor of IMT.
"These findings show that, with lifelong exposure to high levels of cardiovascular disease risk factors, women with PCOS may begin to develop atherosclerosis by the age of 45, which is younger than is seen in the normal population," explained Dr. Talbott. "These results are consistent among the PCOS women studied, regardless of their weight."
In 1992, Dr. Talbott led a study showing that women ages 20-49 with PCOS had elevations in other cardiovascular disease risk factors compared with controls of similar age. These risk factors included a higher body mass index and waist-to-hip ratio, increased LDL cholesterol, insulin and systolic blood pressure, and lower HDL ("good") cholesterol. LDL cholesterol levels were higher for PCOS women under the age of 40, even among those who were relatively slender. Normally, risk factors such as high LDL levels are more common in overweight individuals. Among participants age 40 and older, the difference in LDL levels between cases and controls was less evident. This is due to women in that age group reaching perimenopause, when control women are likely to experience increases in LDL levels and "catch up" to PCOS women.
Both studies were supported by the National Institutes of Health (NIH). Dr. Talbott recently received an additional NIH research grant of $1.7 million to evaluate factors affecting the progression of carotid atherosclerosis in PCOS women over a five-year period. The study, slated to begin in March 2001, will use electron beam computed tomography to evaluate coronary artery calcification, a potential predictor of cardiovascular events.
Established in 1948, the GSPH at the University of Pittsburgh is world-renowned for contributions that have influenced public health practices and medical care for millions of people. It is the only fully accredited school of public health in the Commonwealth of Pennsylvania and is one of the top-ranked schools of public health in the United States. It is one of eight schools across the nation to be designated a Public Health Training Center by the U.S. Department of Health and Human Services. For more information about the GSPH, access the school's website at www.pitt.edu/~gsphhome.