Background: Information on sex hormone levels in young children is currently lacking, because those levels are generally below the lower limit of quantitation of conventional immunoassay methods. We investigated sex differences in serum levels of sex hormones in relation to upstream hormones and other background factors in young children, using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Methods: This cross-sectional study enrolled 151 children (80 boys and 71 girls) aged around 6 years, who participated in a pilot study of the Japan Environment and Childrens Study (JECS). Serum levels of estradiol (E2), testosterone (T), and dehydroepiandrosterone sulfate (DHEA-S) were measured by LC-MS/MS, and serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured by chemiluminescent enzyme immunoassay. A gender-stratified multiple linear regression model with sex hormones as the outcome variable and upstream hormone levels and background factors (height, abdominal girth, and specimen-collection time) as explanatory variables was generated.
Results: There were no significant gender-related differences in levels of T and DHEA-S, but serum levels of E2 and FSH were significantly higher in girls than boys. Median (interquartile range) levels of E2 in girls and boys were 1.02 (0.651.58) and 0.10 (0.060.16) pg/ml, respectively (Welchs t-test; P<0.001). The Wald test suggested that T levels in both boys and girls were associated with DHEA-S levels (both P<0.001) and were higher in the morning (P=0.007 and 0.006, respectively). Furthermore, E2 levels in boys were significantly associated with T levels (=0.018), while E2 levels in girls were significantly associated with both T and FSH levels (P<0.001 and 0.010, respectively).
Conclusion: Obvious gender differences in E2 levels exist even in young children. Furthermore, E2 levels in pre-pubertal girls are associated with both DHEA-S and FSH.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology