Context: Despite the high prevalence of hyperandrogenemia, the principal biochemical abnormality in women with polycystic ovary syndrome (PCOS), a definitive endocrine marker for PCOS has so far not been identified.
Objective: To identify a tentative diagnostic marker for PCOS, we compared serum levels of sex steroids, their precursors, and main metabolites in women with PCOS and controls.
Design and methods: In this cross-sectional study of 74 women with PCOS and 31 controls, we used gas and liquid chromatography/mass spectrometry to analyze serum sex steroid precursors, estrogens, androgens, and glucuronidated androgen metabolites; performed immunoassays of SHBG, LH, and FSH; and calculated the LH/FSH ratio.
Results: Androgens and estrogens, sex steroid precursors, and glucuronidated androgen metabolites were higher in women with PCOS than in controls. In multivariate logistic regression analyses, estrone and free testosterone were independently associated with PCOS. The odds ratios per sd increase were 24.2 for estrone [95% confidence interval (CI), 4.0-144.7] and 12.8 for free testosterone (95% CI, 3.1-53.4). In receiver operating characteristic analyses, the area under curve was 0.93 for estrone (95% CI, 0.88-0.98) and 0.91 for free testosterone (95% CI, 0.86-0.97), indicating high sensitivity and specificity.
Conclusion: Women with PCOS have elevated levels of sex steroid precursors, estrogens, androgens, and glucuronidated androgen metabolites as measured with a specific and sensitive mass spectrometry-based technique. The combination of elevated estrone (>50 pg/ml) and free testosterone (>3.3 pg/ml) appeared to discriminate with high sensitivity and specificity between women with and without PCOS.