Abstract
OBJECTIVE: This study investigated changes in serum phoenixin (PNX) levels in boys with central precocious puberty (CPP), aiming to evaluate its diagnostic and therapeutic relevance and identify factors influencing its expression. METHOD: Serum samples were collected from 43 boys with CPP and 48 age-matched prepubertal controls. Participants were further divided into overweight/obese and normal-weight subgroups based on body mass index (BMI). Levels of phoenixin-14 (PNX-14) and phoenixin-20 (PNX-20) were measured using enzyme-linked immunosorbent assay (ELISA). Correlations with luteinizing hormone (LH), testosterone, and BMI were analyzed. Multiple linear regression identified independent influencing factors, and receiver operating characteristic (ROC) analysis assessed the diagnostic performance of PNX. Twelve CPP boys were followed for 6 months after gonadotropin-releasing hormone analog (GnRHa) treatment. RESULTS: PNX-20 and PNX-14 levels were significantly higher in the CPP group than in controls (P = 0.001). Among subgroups, the overweight/obese CPP group exhibited the highest levels. Both PNX forms were positively correlated with baseline LH, testosterone, and BMI; PNX-14 was most strongly associated with LH, and PNX-20 with BMI. ROC analysis showed moderate diagnostic value for PNX-14 (AUC: 0.710) and PNX-20 (AUC: 0.696), with a combined AUC of 0.718. Following treatment, levels of PNX-20, LH, follicle-stimulating hormone (FSH), and testosterone significantly declined, while PNX-14 remained unchanged. CONCLUSIONS: PNX is associated with pubertal progression and BMI in boys with CPP. While not suitable as a standalone diagnostic marker, PNX - especially PNX-20 - may serve as a useful adjunct for diagnosis and treatment monitoring.