SUN-LB18 Serum 25-Hydroxyvitamin D Is Not Associated With the Type of Central Precocious Puberty in Girls

[Objective] To evaluate the clinical value of serum 25-hydroxyvitamin D (25OHD) in girls with different types of central precocious puberty (CPP), in order to provide basis for the clinical diagnosis and treatment. [Methods] 340 CPP girls diagnosed in our hospital from January 2016 to January 2018 were enrolled and retrospectively studied. According to the progression of Tanner stage ≥1 during 6 months, bone age(BA) levels were higher than chronological age of more than 1 year. 226 patients were included in the rapidly progressive CPP group (RP-CPP), while 114 patients were included in the slowly progressive CPP group (SP-CPP) as a control. We analyzed the correlation between serum 25OHD levels and the different puberty characteristics (BA, disease course, body mass index (BMI), bone mineral density (BMD), serum LH peak to FSH peak ratio (LHP/FSHP), insulin-like growth factor 1(IGF1)) of two groups. According to sunshine duration, the sampling season was divided into two groups (December to May, June to November), then we compare the correlation between different serum 25OHD levels and season of sampling as well as the different puberty characteristics respectively. [Results] (1) The mean serum 25OHD levels of CPP girls were 15.89±6.87ng/ml. The 25OHD levels of 68 (20.0%), 95 (27.9%) and 167 (49.1%) patients were <10, 10-15 and 16-29 ng/mL, respectively. Only 10 (2.9%) patients had normal 25OHD (>30 ng/mL). (2) No significant difference in serum 25OHD levels between RP-CPP group and SP-CPP group (F =0.809, p=0.369) was found. There is no correlation of BMD and disease course between the two groups (p>0.1). Bone age, BMI, LHP/FSHP and IGF1 levels in RP-CPP group were higher than SP-CPP group (P<0.05). Logistic regression analysis showed that BMI, LHP/FSHP and IGF1 were the independent risk factors for CPP (OR 2.690, 1.005, 3.288, respectively). (3) There were significant differences among different serum 25OHD levels as for season, disease course and IGF1 (p<0.05). The correlation with the season was the highest (r=0.402, p<0.001). [Conclusions] (1) Vitamin D levels are generally insufficient in CPP girls and are not related to different types of CPP. (2) The higher BMI, IGF1, LHP/FSHP levels are, the easier CPP girls will transfer to RP-CPP, but not associated with vitamin D levels. (3) CPP girls suffer from vitamin D deficiency in seasons of winter and spring easilier.