Sex hormone binding globulin, free estradiol index, and lipid profiles in girls with precocious puberty

PURPOSE: Sex hormone-binding globulin (SHBG) modulates the availability of biologically active free sex hormones. The regulatory role of SHBG might be important in the relationship between hormone levels and the modification of lipid profiles in girls with precocious puberty. However, few studies have evaluated the relationship of SHBG, free estradiol index (FEI), and lipid levels in these girls. METHODS: One hundred and nine girls less than 8 years of age with pubertal development were enrolled. FEI was calculated with SHBG and estradiol (E2). We analyzed SHBG between peak luteinizing hormone (LH)≥5 (IU/L) (group 1) and LH<5 (IU/L) (group 2) through a gonadotropin releasing hormone stimulation test. RESULTS: Body mass index (BMI) standard deviation score (SDS) was higher in group 2 than in group 1 (P=0.004). Serum SHBG levels did not differ and FEI was not higher in group 1 (P=0.122). Serum cholesterol, HDL, and LDL did not differ; however, triglyceride levels were higher in group 2 (P=0.023). SHBG was negatively correlated with bone age advancement, BMI, BMI SDS, and FEI, and was positively correlated with HDL. However, SHBG was not correlated with E2 or peak LH. CONCLUSION: Serum SHBG itself might not be associated with precocious puberty in girls, but it might be related to BMI and lipid profiles. Further studies are needed to reveal the relationship between sex hormone and obesity in girls with precocious puberty.