What hormones should be tested in a patient with suspected Polycystic Ovary Syndrome (PCOS) presenting with hirsutism?

Recommended Hormone Tests for PCOS with Hirsutism

For patients with suspected PCOS presenting with hirsutism, total testosterone (TT) and free testosterone (FT) should be the first-line laboratory tests to assess biochemical hyperandrogenism. 1

Primary Hormone Panel

• Total testosterone (TT) - Has high specificity (86%) and good sensitivity (74%) for diagnosing biochemical hyperandrogenism in PCOS 1
• Free testosterone (FT) - Should be assessed by equilibrium dialysis or calculated using the Free Androgen Index (FAI) 1
• Sex hormone binding globulin (SHBG) - Important for calculating FAI and evaluating bioavailable testosterone 1
• Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) - To assess ovarian function and LH:FSH ratio 1

Secondary Hormone Tests to Consider

If total or free testosterone levels are not elevated, consider:

• Androstenedione (A4) - Has sensitivity of 75% but lower specificity (71%) 1
• Dehydroepiandrosterone sulfate (DHEAS) - Useful to identify adrenal sources of androgens, though with lower specificity (67%) 1

Testing Methods

• Liquid chromatography with tandem mass spectrometry (LC-MS/MS) is the preferred method for measuring androgens due to superior sensitivity and specificity compared to immunoassays 1
• If LC-MS/MS is unavailable, FAI can be employed as an alternative to direct FT measurement 1

Additional Tests to Rule Out Other Conditions

• Thyroid-stimulating hormone (TSH) - To exclude thyroid disease 1
• Prolactin - To rule out hyperprolactinemia 1
• Two-hour oral glucose tolerance test - For screening diabetes risk, as PCOS patients have increased risk of type 2 diabetes 1
• Fasting lipid profile - To assess cardiovascular risk factors 1

Special Considerations for Differential Diagnosis

• For patients with features suggesting Cushing's syndrome (buffalo hump, moon facies, abdominal striae), consider screening for this condition 1
• For suspected non-classic congenital adrenal hyperplasia, consider 17-hydroxyprogesterone testing 1
• For prepubertal children with hirsutism, consider growth charts and bone age assessment before specific hormonal testing 1

Interpretation Considerations

• The diagnostic accuracy of total testosterone has been shown to be higher when using Rotterdam criteria (sensitivity 77%, specificity 83%) compared to NIH criteria (sensitivity 51%, specificity 94%) 1
• Hirsute patients typically present with higher total testosterone and FAI values than non-hirsute patients 2
• Total testosterone and FAI positively correlate with hirsutism severity as measured by modified Ferriman-Gallwey scoring 2

Common Pitfalls and Caveats

• Direct immunoassay methods for measuring free testosterone are highly inaccurate due to low serum concentrations 1
• Testosterone levels may be affected by fluctuations in SHBG, which can be influenced by age, weight, and medications 1
• Anti-Müllerian hormone (AMH) should not yet be used as a single test for PCOS diagnosis despite its correlation with polycystic ovary morphology 1
• Emerging research suggests 11-oxyandrogens (particularly 11-ketotestosterone) may be better predictors of PCOS than traditional androgens, but these are not yet part of standard clinical testing 3