A Review of the Clinical Diagnosis of Polycystic Ovary Syndrome (PCOS) Using Serum Testosterone, C-Peptide, and Fasting Insulin Levels

Polycystic ovarian syndrome (PCOS) is a complex hormonal condition marked by polycystic ovaries, inconsistent ovulation, and excess androgens. PCOS affects people of normal weight as well, yet it has historically been associated with obesity, which makes diagnosis challenging. Current diagnostic guidelines, like the Rotterdam criteria and the Androgen Excess and PCOS Society's, mostly concentrate on biochemical and clinical indicators. However, there is growing evidence that fasting insulin levels, C-peptide, and serum testosterone levels should be measured as further diagnostic criteria, especially for PCOS populations that are lean and obese. Online databases, including PubMed, Google Scholar, and Scopus, were searched to identify articles, review papers, and clinical guidelines published up to 2023. The justification, new data, and clinical implications of incorporating fasting insulin, C-peptide, and serum testosterone measurement into the diagnostic framework for PCOS were explored in this review. It also acknowledges the difficulties and potential avenues for future research. Metabolic markers like fasting insulin, C-peptide, and serum testosterone levels are increasingly being recognized as important in PCOS diagnosis, particularly in cases of lean PCOS. To standardize these tests and successfully incorporate them into clinical practice, however, further study and cooperation are required.