Introduction
Specifically, women with risk factors for CVDs are at greater risk of developing atherosclerosis and experiencing fatal and nonfatal CVD events. Suppose the event of cardiovascular disease is assessed by more stringent criteria, such as an increase in mortality from CVD or premature mortality from CVD or an increased incidence of cardiovascular events (stroke and myocardial infarction). In that case, there is little published evidence that women with PCOS are unduly affected.
This pyramid is still incomplete in women with PCOS, as the bulk of research suggests increased risk factors. Still, relatively little research has been published on atherosclerosis, and even less has been posted on more frequent or earlier events. Researchers studied women with metabolic syndrome for reproductive stigmata of PCOS and found they have no higher likelihood of having PCOS than other segments of the population; only about one-half have a history of oligomenorrhea [although oligomenorrhea was twice as standard among those with PCOS (14)].
Intensive testing can reveal no insulin resistance in up to 50% of obese PCOS women (18, 19), and this prevalence may be even lower in nonobese women with PCOS (20, 21). Women with PCOS have a metabolic profile similar to those with insulin resistance syndrome, characterized by hyperinsulinemia, mild glucose intolerance, dyslipidemia, and hypertension (4). In such an environment, there is substantial encouragement to publish supporting studies. Many studies have been published that identify CVD risk factors associated with PCOS, such as obesity, dyslipidemia, glucose intolerance, diabetes, and occasionally hypertension.
It is almost entirely inferential that women with PCOS have a higher cardiovascular risk (Ref. 8 and 23 and Fig. 2). We will examine the association between reproductive abnormalities individually and together (Fig. 1) and the likelihood of cardiovascular events and having an adverse cardiovascular risk profile. Women continue to die from cardiovascular disease, with aging considered one of the significant risk factors for the development of atherosclerosis.
For example, a large case series of over 1700 women in the United Kingdom reported a high percentage of nonobese women with PCOS [80 percent (Ref. 15)]. Section V.C. discusses in detail that clinical hypertension is rare in many women with PCOS, as is dyslipidemia, and dyslipidemia is not always present in insulin-resistant women.
A pair of gynecologists from Chicago, Stein, and Leventhal (1), first recognized PCOS in the 1930s by observing its symptoms of amenorrhea, hirsutism, and polycystic ovaries. These symptoms also diagnose women with PCOS (Fig. 1). Although abnormal gonadotropin production (especially an excess of L.H. secretion) is widespread in women with PCOS, it has not been used as a diagnostic criterion in recent studies (28). As a result, it will not be discussed further in this review.
As women with PCOS were found to have reduced insulin sensitivity and compensatory hyperinsulinemia, metabolic abnormalities beyond obesity began to emerge. Even though the size or morphology of the ovaries are not included in PCOS diagnosis (despite the original Stein-Leventhal Syndrome identification of enlarged PCO), there is rich literature showing the significant overlap between PCO and endocrine abnormalities anovulation and hyperandrogenism (15, 27). Several studies have identified insulin resistance syndrome (or syndrome X) as a risk factor for developing type 2 diabetes and cardiovascular disease.
It is not always the case that women with PCOS have documented insulin resistance by invasive dynamic testing such as a euglycemic clamp or frequently administered intravenous glucose tolerance test. Women with PCOS face limited long-term follow-up because of varying or age-specific diagnostic criteria. PCOS has been studied with small sample sizes, mainly among premenopausal women with reproductive capacity and little follow-up. Having no universally accepted diagnostic criteria for the syndrome makes comparing cardiovascular risk assessment studies complex.