Stimulated Hyperinsulinemia Is Independently Associated with Higher Serum DHEAS in PCOS: A Retrospective Study

Background/Objectives: Increased dehydroepiandrosterone sulfate (DHEAS) is used as a diagnostic marker of hyperandrogenism in women with polycystic ovary syndrome (PCOS). The mechanisms of adrenal hyperandrogenism in PCOS include hyperinsulinism as a potential stimulator, but results of studies associating insulinemia with DHEAS in PCOS are conflicting. The objective of this study was to evaluate the factors associated with DHEAS levels in PCOS, focusing on insulinemia. Methods: We performed a cross-sectional retrospective study in a total of 257 patients with PCOS (Rotterdam criteria) evaluated in our tertiary center of endocrinology. Clinical and biochemical parameters included body mass index (BMI), serum DHEAS, total testosterone and sex hormone-binding globulin (SHBG), insulin and glycaemia at fasting and 2 h during the oral glucose tolerance test (OGTT), and homeostasis model assessment for insulin resistance (HOMA-IR) was calculated. Results: The comparative analysis of PCOS divided into DHEAS tertiles revealed that patients in the upper tertile were younger (p < 0.05) and had higher 2 h insulin in the OGTT (p < 0.05) than the lower tertile, while fasting insulin and HOMA-IR were not different. DHEAS correlated negatively with age (r = -0.146, p < 0.05) and positively with 2 h insulinemia (r = 0.246, p < 0.001), while fasting insulin and HOMA-IR did not correlate with DHEAS in all PCOS. In stepwise linear regression models, 2 h insulin remained a positive independent predictor for DHEAS only in non-obese PCOS (p < 0.0001). Conclusions: Our data indicate a positive association between stimulated insulin and DHEAS in PCOS. Two-hour insulin in OGTT was an independent predictor of DHEAS in non-obese PCOS, suggesting that DHEAS might be a reliable marker for the stimulatory insulin effect on adrenal steroidogenesis in non-obese PCOS patients.