Serum Asprosin in Women of Reproductive Age: Metabolic and Reproductive Associations and Discriminatory Performance in a Cross-Sectional Study

Background: The relationships of serum asprosin with metabolic and reproductive hormonal parameters in women of reproductive age, as well as its discriminatory performance for overweight or obesity, remain incompletely understood.Objective: This study aimed to evaluate the associations of serum asprosin with anthropometric, metabolic, and reproductive hormonal parameters in women of reproductive age and its exploratory discriminatory performance for identifying overweight or obesity.Methods: This single-center cross-sectional observational study included 108 women aged 18-49 years recruited using convenience sampling who were classified according to body mass index (BMI).Anthropometric measurements, glucose metabolism parameters, and hormonal profiles were assessed.Analyses involving reproductive hormones were restricted to samples collected during the early follicular phase (cycle days 3-5).Serum asprosin concentrations were measured using an enzyme-linked immunosorbent assay (ELISA) in 79 participants.Associations between asprosin and the investigated parameters were evaluated using Spearman's rank correlation analysis.The association between asprosin and anti-Mullerian hormone (AMH) was assessed using partial Spearman rank correlation, adjusting for BMI and age.The discriminatory performance of asprosin was assessed using receiver operating characteristic (ROC) curve analysis.Results: Serum asprosin levels were positively correlated with BMI (ρ = 0.645; p < 0.001), waist circumference (ρ = 0.668; p < 0.001), fasting insulin (ρ = 0.548; p < 0.001), and the homeostatic model assessment of insulin resistance (HOMA-IR) (ρ = 0.567; p < 0.001).A weaker but statistically significant correlation was observed with fasting glucose (ρ = 0.349; p = 0.003).The area under the ROC curve (AUC) for identifying participants with BMI ≥25 kg/m² was 0.837 (95% confidence interval (CI): 0.750-0.924).At the optimal cutoff of 1.21 ng/ml, sensitivity was 71.93%, and specificity was 95.45%.The cutoff was derived and evaluated in the same sample without internal or external validation.An unadjusted inverse correlation was observed between asprosin and AMH (ρ = -0.389;p = 0.005); however, this association was no longer significant after adjustment for BMI and age using partial Spearman correlation (ρ = -0.074;p = 0.616).Conclusion: Higher serum asprosin concentrations were associated with general and abdominal adiposity, higher insulin concentration, and insulin resistance in women of reproductive age.These preliminary associations do not establish causality or support the use of asprosin as a standalone diagnostic test.Larger prospective multicenter studies with appropriate adjustment for confounders and independent validation are required to establish its clinical utility and validate the exploratory cutoff.