The relationship between pubertal gynecomastia, prostate specific antigen, free androgen index, SHBG and sex steroids.

Abstract

To investigate the relationships between pubertal gynecomastia, prostate-specific antigen (PSA), free androgen index (FAI), sex hormone-binding globulin (SHBG) and sex steroids.
A total of 61 male adolescents (10-17 years old; mean: 13.67 +/- 1.08) with gynecomastia were enrolled into the study group. A total of 65 healthy age-matched adolescents were included in the control group. Body mass index (BMI), Tanner staging, testis volume, stretched penis length (SPL) and bone age were evaluated. Serum follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), testosterone, free testosterone, SHBG, PSA levels were determined and FAI was calculated.
In the study group, free testosterone (p = 0.012) and FAI (p = 0.05) were significantly lower than the control group. In the control group, SHBG levels decreased (p < 0.05) and FAI increased (p < 0.05) significantly with increasing Tanner stages; however, no such difference was observed in the study group (p > 0.05). High FAI was found to decrease the risk of gynecomastia (odds ratio: 0.211, 95% confidence interval: 0.064-0.694, p = 0.01). PSA showed a positive correlation with FAI, free testosterone, Tanner staging, testosterone, E2 and LH levels.
PSA is a good indicator of androgen activity during puberty. However, owing to FAI remaining as the single significant variable for pubertal gynecomastia, we suggest that it is still the best parameter to elucidate the etiopathogenesis of gynecomastia as well as other pubertal developmental abnormalities in male adolescents, and further longitudinal studies are needed to investigate the relationships between PSA and FAI in puberty.