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Polycystic Ovarian Syndrome for the ABIM

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Polycystic Ovarian Syndrome (PCOS) for the American Board of Internal Medicine Exam
  • Definition:
    • Polycystic ovarian syndrome (PCOS) is a common endocrine disorder affecting women of reproductive age, characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. It is a leading cause of infertility and metabolic complications in women.
  • Etiology and Pathophysiology:
    • The exact cause of PCOS is unknown, but genetic and environmental factors contribute to its pathogenesis. It is characterized by an interplay of hyperandrogenism, insulin resistance, and abnormal folliculogenesis.
    • Hyperandrogenism:
    • Excess androgen production occurs in the ovaries and adrenal glands, leading to hirsutism, acne, and alopecia. Elevated androgens disrupt follicular development, leading to anovulation.
    • Insulin Resistance:
    • Insulin resistance is prevalent in PCOS and contributes to hyperinsulinemia. Insulin acts synergistically with luteinizing hormone (LH) to stimulate androgen production in the ovaries.
    • Folliculogenesis:
    • High androgen levels and insulin resistance interfere with follicle maturation, resulting in multiple small cysts in the ovaries and chronic anovulation.
PCOS hormones
Clinical Manifestations
  • Menstrual Irregularities:
    • Commonly manifests as oligomenorrhea (infrequent menstruation) or amenorrhea (absence of menstruation), stemming from chronic anovulation. Patients may also experience prolonged and irregular menstrual cycles.
  • Hyperandrogenism:
    • Hirsutism: Excess hair growth in a male pattern (face, chest, and abdomen).
    • Acne and Seborrhea: High levels of circulating androgens stimulate sebaceous glands, leading to acne and oily skin.
    • Alopecia: Male-pattern baldness may occur in severe cases.
  • Metabolic Disturbances:
    • Insulin resistance often leads to obesity, central adiposity, dyslipidemia, and increased risk for type 2 diabetes mellitus (T2DM). Approximately 50-80% of women with PCOS are overweight or obese.
    • Increased cardiovascular risk due to hypertension, dyslipidemia (elevated LDL, reduced HDL), and an elevated inflammatory state.
  • Infertility:
    • Chronic anovulation associated with PCOS makes it one of the most common causes of infertility in women. In cases where ovulation occurs, luteal phase defects and suboptimal endometrial receptivity may further impair fertility.
  • Acanthosis Nigricans:
    • A dermatologic manifestation of insulin resistance presenting as dark, velvety patches of skin, commonly in the axilla, neck, and groin.
Diagnostic Criteria
The diagnosis of PCOS is based on the Rotterdam criteria, which require the presence of at least two of the following three features, provided other causes of hyperandrogenism and ovulatory dysfunction are excluded:
1. Oligo- or Anovulation: Often presenting as irregular or absent menstrual cycles. 2. Hyperandrogenism: Clinical signs (e.g., hirsutism, acne) or biochemical evidence (elevated serum androgens). 3. Polycystic Ovaries: Identified on ultrasound as the presence of ≥12 follicles in each ovary (2–9 mm in diameter) or increased ovarian volume (>10 mL).
  • Exclusion of Other Disorders:
    • Hyperprolactinemia, Hypothyroidism, and Androgen-secreting Tumors: These conditions can mimic PCOS symptoms and should be excluded.
    • Congenital Adrenal Hyperplasia (CAH): CAH can present with hyperandrogenism and must be ruled out by measuring 17-hydroxyprogesterone.
Laboratory Evaluation
  • Hormonal Assessment:
    • Total and Free Testosterone: Elevated in most cases of PCOS, reflecting hyperandrogenism.
    • LH and FSH: Typically, LH is elevated, and the LH/FSH ratio may exceed 2:1, though this finding is not essential for diagnosis.
    • Estradiol: Usually normal or slightly elevated due to continuous, unopposed estrogen production in the absence of regular ovulation.
  • Metabolic Screening:
    • Oral Glucose Tolerance Test (OGTT): Assesses glucose intolerance or diabetes; a fasting glucose and 2-hour glucose level after a 75-gram load is recommended.
    • Lipid Profile: To evaluate dyslipidemia, which is common in PCOS.
Management
Management of PCOS is individualized and may focus on addressing menstrual irregularities, hyperandrogenic symptoms, metabolic abnormalities, and infertility.
Pharmacologic Treatments
  • Hormonal Contraceptives:
    • Combined Oral Contraceptives (COCs): First-line therapy for menstrual irregularities and hyperandrogenism; they suppress LH secretion, reduce ovarian androgen production, and increase SHBG, which lowers free testosterone levels.
    • Progestin-Only Therapy: For patients contraindicated for estrogen, progestin-only options (e.g., medroxyprogesterone) may be used to regulate menstrual cycles and reduce endometrial hyperplasia risk.
  • Anti-Androgens:
    • Spironolactone: Used for hirsutism and acne; blocks androgen receptors and inhibits 5α-reductase.
    • Finasteride: Inhibits 5α-reductase, lowering the conversion of testosterone to its more potent form, dihydrotestosterone (DHT). Typically used as adjunctive therapy in patients not responding to spironolactone.
  • Metformin:
    • Primarily used for insulin resistance and glucose intolerance; improves insulin sensitivity, promotes weight loss, and may induce ovulation in some patients. Often used in combination with lifestyle modification for optimal metabolic outcomes.
  • Ovulation Induction:
    • Letrozole: Preferred first-line agent for ovulation induction in patients with infertility due to PCOS; works by inhibiting aromatase, leading to increased follicle-stimulating hormone (FSH) levels.
    • Clomiphene Citrate: Second-line option for inducing ovulation. It is a selective estrogen receptor modulator that increases FSH, promoting follicle maturation and ovulation.
Surgical Intervention
  • Laparoscopic Ovarian Drilling:
    • Used in cases unresponsive to medical therapy for ovulation induction; involves the destruction of a portion of the ovarian tissue to reduce androgen production and promote ovulation.
Management of Cardiometabolic Risk
    • Blood Pressure Control: Regular monitoring and antihypertensive treatment as needed, particularly in women with dyslipidemia or obesity.
    • Diabetes Screening: Routine screening for diabetes and insulin resistance due to elevated risk.
    • Lipid Management: Statin therapy may be indicated for dyslipidemia.
Long-Term Complications
Women with PCOS are at higher risk for several long-term complications, including:
  • Endometrial Hyperplasia and Cancer: Chronic anovulation and unopposed estrogen exposure increase the risk of endometrial hyperplasia, which can progress to endometrial cancer.
  • Type 2 Diabetes Mellitus: Insulin resistance increases the lifetime risk of developing type 2 diabetes.
  • Cardiovascular Disease: PCOS is associated with an increased risk for cardiovascular disease due to metabolic abnormalities, including hypertension, dyslipidemia, and obesity.
  • Obstructive Sleep Apnea (OSA): Associated with insulin resistance and obesity, which are common in women with PCOS.
Key Points
  • PCOS is an endocrine disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries, often leading to infertility and metabolic complications.
  • Clinical Features: Include menstrual irregularities, hyperandrogenic symptoms (hirsutism, acne), and metabolic abnormalities like insulin resistance and dyslipidemia.
  • Diagnosis relies on the Rotterdam criteria, which require two of three findings: oligo/anovulation, hyperandrogenism, and polycystic ovaries on ultrasound, after ruling out other causes.
  • Management includes lifestyle modification, hormonal therapy (COCs for cycle regulation), anti-androgens (spironolactone for hirsutism), and ovulation induction (letrozole for infertility).
  • Complications: Women with PCOS are at increased risk for endometrial hyperplasia, type 2 diabetes, cardiovascular disease, and obstructive sleep apnea.

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