From the Guidelines
Polycystic ovary syndrome (PCOS) is a complex endocrine disorder characterized by three main components: oligo-anovulation, clinical and/or biochemical signs of hyperandrogenism, and polycystic ovaries on ultrasound, with at least two of these criteria required for diagnosis, as per the Rotterdam criteria 1. The primary components of PCOS include:
- Irregular or absent menstrual periods due to infrequent or absent ovulation
- Elevated androgen levels causing symptoms like excess facial and body hair, acne, and male-pattern baldness
- Polycystic ovaries containing multiple small follicles visible on ultrasound Other key components of PCOS include:
- Insulin resistance, affecting 70-80% of women with PCOS and contributing to weight gain, particularly around the abdomen
- Metabolic abnormalities, including increased risk for type 2 diabetes, high cholesterol, and cardiovascular disease
- Hormonal imbalances beyond androgens, including elevated luteinizing hormone (LH) relative to follicle-stimulating hormone (FSH), which disrupts normal ovulation
- Chronic low-grade inflammation, exacerbating insulin resistance and other symptoms These components interact in complex ways, creating a cycle where insulin resistance worsens androgen excess, which further disrupts ovulation and metabolic function. The diagnosis of PCOS is based on the presence of at least two of the three main criteria, with the exclusion of other relevant disorders, as per the Rotterdam criteria 1. Recent studies have highlighted the importance of accurate androgen measurement in the diagnosis of PCOS, with total testosterone (TT) and free testosterone (FT) being the most reliable markers 1. The use of anti-Müllerian hormone (AMH) as a diagnostic marker for PCOS is also being explored, with studies suggesting that it may be a useful alternative to ultrasound in certain cases 1. However, further research is needed to determine the optimal cut-offs for AMH and to standardize its measurement across different assays and populations 1.
From the Research
Components of Polycystic Ovary Syndrome (PCOS)
The components of PCOS can be summarized as follows:
- Hyperandrogenism: characterized by excess androgen production, leading to symptoms such as hirsutism, acne, and androgenetic alopecia 2, 3, 4, 5
- Oligo-anovulation: irregular or absent menstrual cycles, resulting from defective follicle selection and ovulation 2, 3, 4, 6
- Polycystic ovarian morphology: presence of multiple small cysts on the ovaries, detected by ultrasound 2, 3, 6
- Metabolic abnormalities: insulin resistance, obesity, type 2 diabetes, dyslipidemia, and increased risk of cardiovascular disease 2, 3, 6, 5
Phenotypes of PCOS
There are four recognized phenotypes of PCOS, each with different long-term health and metabolic implications:
- Hyperandrogenism + oligo-anovulation + polycystic ovarian morphology
- Hyperandrogenism + oligo-anovulation
- Hyperandrogenism + polycystic ovarian morphology
- Oligo-anovulation + polycystic ovarian morphology 3
Pathophysiology of PCOS
The pathophysiology of PCOS is complex and multifactorial, involving abnormalities in: