An Association of Elevated Serum Prolactin with Phthalate Exposure in Adult Men

Abstract

Objective To investigate the associations of hormone circulation with phthalate exposure in adult men. Methods Semen and serum samples were collected from 118 men who were suspected of infertility. Phthalate diesters including dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP) in both semen and serum samples were measured, along with serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), estradiol (E 2) and prolactin (PRL). Results Serum PRL was positively associated with serum DBP and DEHP and semen DEHP in all models of Spearman correlation, linear regression and binary logistic regression. In linear regression models adjusted for potential confounders and excluding subjects with undetectable phthalates, a 10-fold increase in semen DEHP was associated with a 23% increase in serum PRL, as well as a 26% increase in serum DBP and a 20% increase in serum DEHP. In logistic regression models all subjects demonstrated a dose-response relationship between above reference value PRL and semen DEHP (odds ratio per tertile adjusted for potential confounders = 1.0, 1.70, 3.50; P for trend = 0.01), and serum DBP (1.0, 1.10, 2.62; P for trend = 0.04), and serum DEHP (1.0, 1.46, 4.69; P for trend < 0.01). A positive correlation between serum estradiol and semen DEHP (linear regression), and an inverse correlation between semen DBP and serum testosterone and T:E 2 ratio (Spearman correlation) were also established. Conclusion Serum PRL is suggested to be positively associated with both DBP and DEHP exposure in adult men.