Prevalence of vitamin D deficiency in girls with idiopathic central precocious puberty

The relationship between vitamin D deficiency and idiopathic central precocious puberty （ICPP） has been recently documented. In this study, 280 girls diagnosed with ICPP and 188 normal puberty control girls of similar ages were enrolled and retrospectively studied. The ICPP group had significantly lower serum 25- hydroxyvitamin D （25[OH]D） levels than the control group. Furthermore, a nonlinear relationship was found between serum 25[OH]D and ICPP, and a cut-offpoint for serum 25[OH]D was found at 31.8 ng/ml for ICPP with and without adjusting the different confounding factors. Girls with serum 25[OH]D 〉~ 31.8 ng/ml had a lower odds ratio （unadjusted： OR 0.36, 95% CI 0.15 to 0.83, P 〈 0.05; height and weight adjusted： OR 0.44, 95~0 CI 0.18 to 1.08, P = 0.072; BMI adjusted： OR 0.36, 95% CI 0.16 to 0.84, P 〈 0.05）. The ICPP subjects with 25[OH]D deficiency had a higher body mass index （BMI） than the subjects from the two other subgroups. Correlation analysis showed that vitamin D level is correlated with BMI and some metabolic parameters in the ICPP group. Our study suggested that vitamin D status may be associated with ICPP risk and may have a threshold effect on ICPP.

Efficacy and Safety of Domestic Leuprorelin in Girls with Idiopathic Central Precocious Puberty： A Multicenter,Randomized, Parallel, Controlled Trial

Background：In central precocious puberty （CPP）,the pulse secretion and release ofgonadotropin-releasing hormone （GnRH） are increased due to early activation of the hypothalamic-pituitary-gonadal axis,resulting in developmental abnormalities with gonadal development and appearance of secondary sexual characteristics.The CPP without organic disease is known as idiopathic CPP （ICPP）.The objective of the study was to evaluate the clinical efficacy and safety of domestic leuprorelin （GnRH analog） in girls with ICPP.Methods：A total of 236 girls with ICPP diagnosed from April 2012 to January 2014 were selected and were randomized into two groups.One hundred fifty-seven girls in the test group were treated with domestic leuprorelin acetate,79 girls in the control group were treated with imported leuprorelin acetate.They all were treated and observed for 6 months.After 6-month treatment,the percentage of children with peak luteinizing hormone （LH） ≤3.3 U/L,the percentage of children with peak LH/peak follicle stimulating hormone （FSH） ratio 〈0.6,the improvements of secondary sexual characteristics,gonadal development and sex hormone levels,the change of growth rate of bone age （BA） and growth velocity,and drug adverse effects between two groups were compared.Results：After the treatment,the percentage of children with a suppressed LH response to GnRH,defined as a peak LH ≤3.3 U/L,at 6 months in test and control groups were 96.80% and 96.20%,respectively,and the percentage of children with peak LH/FSH ratio ≤0.6 at 6 months in test and control groups were 93.60% and 93.70%,respectively.The sizes of breast,uterus and ovary of children and the levels of estradiol （E2） were significantly reduced,and the growth rate of BA was also reduced.All the differences between pre-and post-treatment in each group were statistically significant （P 〈 0.05）,but the differences of the parameters between two groups were not significant （P 〉 0.05）.Conclusions：Domestic leuprorelin is effective and safe in the treatment of Chinese girls with ICPP.Its effectiveness and safety are comparable with imported leuprorelin.

Independent Relationship between Body Mass Index and LH Peak Value of GnRH Stimulation Test in ICPP Girls: A Cross-sectional Study

The effect of obesity on idiopathic central precocious puberty（ICPP） girls is still under discussion. The relationship between body mass index（BMI） and sexual hormone levels of gonadotropin-releasing hormone（GnRH） stimulation test in ICPP girls is controversial and the underlying mechanism is unclear. This study aims to further explore the independent effect of excess adiposity on peak luteinizing hormone（LH） level of stimulation test in ICPP girls and the role of other related factors. A retrospective cross-sectional study was performed on 618 girls diagnosed as having ICPP, including 355 cases of normal weight, 99 cases of overweight and 164 cases of obese. The results showed that obese group had more progressed Tanner stage and no significant difference（P=0.28） in LH peak was found as basal LH value was used as a covariate. The obese group had higher total testosterone（TT）, adrenocorticotrophic hormone（ACTH）, 17-α hydroxyprogesterone（17-αOHP） and androstendione（AN）, with significantly increased fasting insulin（FIN） and homeostasis model of assessment for insulin resistance index（HOMA-IR）. Stratified analysis showed inconsistency of the relationship between BMI-standard deviation score（BMI-SDS） and LH peak in different Tanner stages（P for interaction=0.017）. Further smoothing plot showed linear and non-linear relationship between BMI-SDS and LH peak in three Tanner stages. Then linear regression model was used to analyze the relationship between BMI-SDS and LH peak in different Tanner stages, with and without different confounding factors being adjusted. In B2 stage, BMI-SDS was negatively associated with LH peak. In B3 stage, when BMI-SDS 〈1.5, as BMI-SDS increased, the level of LH peak decreased（model Ⅰ： β=–1.8, 95% CI=–4.7 to 1.1, P=0.214）. When BMI-SDS ≥1.5, BMI-SDS was significantly positively associated with LH peak（model Ⅰ： β=4.5, 95% CI=1.7 to 7.4, P=0.002）. In B4 stage, when BMI-SDS 〈1.5, BMI-SDS was negatively associated with LH peak（model Ⅰ： β=–11.6, 95% CI=–22.7 to –0.5, P=0.049）. When BMI-SDS ≥1.5, BMI-SDS was positively associated with LH peak（model Ⅰ： β=–4.2, 95% CI=–3.3 to 11.7, P=0.28）. It is concluded that there is an independent correlation between BMI-SDS and LH peak of stimulation test in ICPP girls, their relationships are different in different Tanner stages, and the effect of BMI-SDS can be affected by adrenal androgens, estradiol and glucose metabolism parameters.