Sex steroid hormones, leptin, and high-sensitivity C-reactive protein levels in adolescents

Background The association of sex hormones with C-reactive protein (CRP) levels has been reported. However, this association remains unexplored in children in whom important anthropometric and hormonal changes are taking place. Objectives To analyze the association between high-sensitivity CRP (hs-CRP) and testosterone, estradiol and sex hormone-binding globulin (SHBG) levels in a population-based sample of adolescents, and to evaluate the influence of leptin levels on this association. Materials and Methods The sample population of this cross-sectional study was comprised of 338 male and 385 female adolescents, aged 12-16 years. Information on anthropometric variables, hormone, leptin, and hs-CRP levels was available. Results In male adolescents in our study, higher age is significantly associated with higher testosterone levels and with lower leptin and SHBG concentrations across the range of age studied. No significant changes in leptin and SHBG levels by age are observed in females. In males, leptin correlates negatively with testosterone levels (-0.263, p < 0.001), showing a stronger correlation after adjusting by body mass index (BMI) (-0.424, p < 0.001). A significant correlation between hs-CRP and testosterone levels is observed in males after adjusting by BMI, but the correlation disappears after adjusting by leptin. No association between testosterone and hs-CRP was observed in females. The negative association between hs-CRP levels and SHBG remains significant after adjusting by leptin in both sexes but disappears in males after adjusting by BMI. Conclusion The negative association between hs-CRP and testosterone concentrations observed in 12- to 16-year-old males seems to be related to leptin levels which are closely negatively related to testosterone levels in males independently of BMI.