Abstract:
Objective To examine the relationship of environmental endocrine disruptors (EEDs) in serum with precocious puberty in girls.
Methods A case-control study was conducted among 219 girls with precocious puberty diagnosed by endocrinologists in a children's hospital (case group) and 271 healthy girls of four primary schools (control group) in Hangzhou in 2011. The concentrations of 28 EEDs, including 20 phthalates di(2-ethyl hexyl)phthalate (DEHP), di-n-butyl phthalate (DBP), diisodecyl ortho-phthalate (DIDP), di(isobutyl)-1, 2-benzenedicarboxylate (DIBP), di-n-octyl phthalate (DNOP), di-n-hexyl phthalate (DHXP), diethyl phthalate (DEP), dibutyl phthalate A (DAP), etc., 4 metabolites monoethylhexyl phthalate (MEHP), monobutyl phthalate (MBP), monoethyl phthalate (MEP), etc., 1, 1-dichloro-2, 2-bis(4-chlorophenyl)ethane (DDE), 4-octylphenol (4-OP), 4-nonylphenol (4-NP), and bisphenol (BPA), were detected in girls' serum by high performance liquid chromatography-mass spectrometry. Multiple linear regression models were used to analyze the correlation between the concentrations of EEDs and precocious puberty in girls.
Results Totally 14 EEDs were detected, and DDE, DEHP, DIBP, DBP, DIDP, MBP presented high detection rates in both groups (50%-100%). The detection rates of DNOP (χ2=30.191, P<0.001) and DIDP (χ2=71.100, P<0.001) were significantly higher in the case group than in the control group. The serum contents of DDE, DEHP, and DNOP in the case group were much higher than those in the control group (Z=8.350, 3.435, and 5.487, respectively, P<0.001). The serum contents of DEP, DAP, DIBP, DBP, DHXP, MEHP, MBP, and MEP were obviously lower in case group than in the control group (Z=4.389, 9.290, 5.592, 2.962, 4.703, 5.384, 3.607, and 3.650, respectively, P<0.01). Multiple linear regression models showed that concentrations of DNOP (b=0.128, P<0.001) and DDE (b=0.357, P<0.001) were positively associated with precocious puberty, while DAP (b=-0.183, P<0.001) and MEP (b=-0.055, P<0.01) were negatively associated.
Conclusion EEDs positive are detected in both girl groups. The elevated serum levels of DDE and DNOP may be associated with precocious puberty in girls. The le vels of DEP, DAP, DIBP, DBP, DHXP, MEHP, MBP, and MEP are low in girls with precocious puberty.