Metabolic and hormonal profiles in women with hirsutism: a comparison between polycystic ovary syndrome and idiopathic hirsutism

Hirsutism is a common endocrine complaint most frequently associated with polycystic ovary syndrome (PCOS), but it may also occur in idiopathic hirsutism (IH). Because the two conditions differ in long-term metabolic risk and management, distinguishing them is clinically important, yet reliable, routinely available discriminators remain incompletely defined. Rather than re-describing established differences, this study aimed to determine whether routine hormonal and biochemical parameters can help discriminate PCOS from IH in women presenting with hirsutism, independent of the confounding effect of severe obesity. In this retrospective cross-sectional study, 275 women with hirsutism (69 with IH and 206 with PCOS) were evaluated. To minimize the confounding effect of severe obesity, women with a body mass index (BMI) > 40 kg/m² were excluded. Clinical, biochemical, and hormonal parameters were compared between groups, and multivariable logistic regression was performed to identify parameters independently associated with PCOS. Compared with women with IH, women with PCOS had significantly higher triglycerides, alanine aminotransferase (ALT), aspartate aminotransferase (AST), the ALT/AST ratio, thyroid-stimulating hormone (TSH), luteinizing hormone (LH), the LH to follicle-stimulating hormone (FSH) ratio, and total testosterone. In contrast, BMI, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and lipid parameters other than triglycerides did not differ significantly between groups. In multivariable logistic regression, only the LH/FSH ratio (odds ratio [OR] 2.86; 95% confidence interval [CI] 1.589–5.135) and the ALT/AST ratio (OR 2.70; 95% CI 1.057–6.892) remained independently associated with PCOS, whereas total testosterone did not. A model combining these routinely available markers discriminated PCOS from IH with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.728 (95% CI 0.661–0.794), exceeding that of any single marker, with good calibration (Hosmer–Lemeshow p = 0.361). After minimizing the confounding effect of severe obesity, women with PCOS and IH showed comparable classic metabolic indices (fasting insulin, HOMA-IR, and lipids), but differed in hormonal profile and in two routinely available laboratory ratios — LH/FSH and ALT/AST — that were independently associated with PCOS. These inexpensive, widely available ratios may serve as a practical adjunct for distinguishing PCOS-related hirsutism from idiopathic hirsutism, pending prospective validation.