Central precocious puberty is a common endocrine disorder in pediatrics, and its incidence is increasing year by year, with girls having a higher incidence than boys. For girls, more than 80% of the cases are idiopathic central precocious puberty, while the opposite is true for boys, with more than 80% caused by central organic lesions. The prevalence of precocious puberty among children in the coastal areas of China is 0,38%, with a higher prevalence of 0,67% among females, and the prevalence of precocious puberty in the Shanghai area is 100 per million. In mainland China, Jiujiang City, the incidence of precocious puberty in children is 0, 68%, of which girls as high as 1, 25%, boys 0, 11%; in Zhengzhou area, the incidence rate is as high as 0, 74%. In recent years, pediatric endocrinologists have classified ICPP into three forms: fast-progressing type, slow-change type, and relatively slow-growth type according to the process of sexual development and growth rate of children with precocious puberty. In addition to the slowly progressing type of CPP, the rapidly progressing type due to accelerated bone maturation and the relatively retarded type due to the separation of the gonadal axis and the growth axis of CPP, if not diagnosed and treated in a timely manner, will lead to the adult lifelong low height, resulting in many inconveniences such as learning and employment; however, the impact on body weight is not yet determined; and for the girl child, the premature appearance of the second sex syndrome, or even the onset of menstruation, which will cause psychological and behavioral problems, such as uneasiness and fear. Behavioral problems. In addition, scholars at home and abroad have found through long-term observation that it can increase the risk of certain diseases, such as polycystic ovary syndrome, and now we are going to review the current impact of CPP on children’s physical and sexual development. 1 The relationship between CPP and physical development 1. 1 The effect of CPP on children’s height CPP leads to the activation of the hypothalamic-pituitary-gonadal axis, which causes children to enter puberty earlier, accelerates skeletal development, and ultimately leads to premature epiphyseal closure of the children and shortens the period of growth, which in turn affects the adult height of the children. The cause of accelerated skeletal maturation may be closely related to the elevated levels of sex hormones, insulin growth factor and insulin-binding protein in children with CPP, etc. Peamrudee et al. found that the adult height of children with CPP was significantly lower than the predicted adult height. Gu Zaiyan et al. followed up children with CPP and found that their height growth rate decreased significantly after menarche compared with that of their normally developing peers. However, with further research, scholars have found that not all children with CPP will have their lifelong height affected. The slowly progressive type of CPP has little effect on children’s height due to the slow rate of bone growth, whereas the rapidly progressive type has its height greatly affected due to the accelerated bone maturation, and the relatively retarded type has its height greatly affected due to the retardation of bone growth, and separation of the gonadal axis from the growth axis. Of course, there are differences in the degree of influence of CPP on children’s height, which is closely related to the age of onset, the degree of bone age overgrowth, sex hormones, and body mass index. 1,2 The effect of CPP on children’s weight At present, more evidence shows that obesity is one of the risk factors of CPP, so scholars put forward the critical body fat doctrine, that is, only the body fat reaches the lowest threshold in order to maintain a normal menstrual cycle and trigger puberty, especially for girls, according to Rosenfield et al. found that the average age of menarche in girls with a high BMI is 10,2 years old, which is earlier than that of girls with normal BMI. According to Rosenfield et al, the average age of menarche in girls with high BMI is 10,2 years old, 10 months earlier than that of girls with normal BMI. And scholars through clinical observation found that CPP girls’ weight, BMI, fatmass (FM) and FM% are higher than normal children of the same age, and the development time is closely related to BMI. However, the impact of obesity on the sexual development of boys is still controversial; most scholars believe that obesity will lead to delayed sexual development of children, but some scholars have put forward different opinions, Laron through the study found that there is no obvious correlation between the two, Kaplowitz et al. found that the initiation of the sexual development of obese boys have an early start time phenomenon. At the same time, it has also been found that the level of leptin, a hormone closely related to obesity, is significantly higher in children with CPP than in normal children of the same age, and studies have shown that it may be one of the puberty initiating factors. After the initiation of puberty, Kaplowitz et al. suggested that because children’s physical ability to produce enough sex steroid hormones, which can promote the increase of fat, so that children’s weight gain is also possible. Recently, scholars have found that the phenomenon of insulin resistance exists in children with CPP, and Yu Lirong et al. have confirmed that there is a correlation between children with ICPP combined with overweight or obesity and insulin resistance, and it has not yet been clarified whether this phenomenon exists in children with CPP and promotes their weight gain. Because of the common neuroendocrine regulation of CPP and obesity, the effect of CPP on children’s body weight still needs further in-depth research. The effect of CPP on sexual development CPP is one of the most common diseases causing abnormal sexual development in children. Due to the early activation of the HPGA axis in children with CPP, the release of gonadotropins under the stimulation of gonadotropin-releasing hormone (GHRH) increases the level of sex hormones, mainly luteinizing hormone, follicle-stimulating hormone, and estradiol (estrogen (E2)) in girls, especially the level of LH; and in boys, it is testosterone. It is due to the stimulation of sex hormones that children’s internal and external genitalia and secondary sexual symptoms appear earlier. Although the developmental pattern of children with CPP after the initiation of puberty is the same as that of children with normal pubertal development, Cai Depei et al. suggested that due to the shorter sexual development time of children with precocious puberty, the development of their internal genital organs may be less mature and smaller in volume. In addition, in recent years, some studies have shown that CPP has an increased likelihood of developing diseases such as polycystic ovary syndrome (PCOS), which may be related to a series of changes in the endocrine environment of CPP children, such as an increase in the levels of IGF-I, insulin, Kisspeption, etc., a decrease in the level of Ghrelin, and a decrease in the emergence of insulin resistance, and so on. In the past, foreign scholars reported that early menarche would increase the occurrence of breast tumor. 3, CPP treatment on physical and sexual development Gonadotropin-releasing hormone analogues are internationally recognized as the most important drugs for the treatment of CPP, and their application began in 1980, but not all CPP need treatment, for <9 years old male children; <8 years old female children with signs of rapid development of the secondary sex syndrome, i.e., those with accelerated linear growth, skeletal maturation, and the development of the secondary sex syndrome; the predicted Patients whose adult height is less than 2 standard deviations from normal should be treated; Currently, the effect of treatment is monitored clinically by LH, bone age, and ultrasound of the reproductive system, but there are still many problems in the process of monitoring, so the optimal policy of post-treatment monitoring still needs long-term research. And the evaluation of treatment effect is mainly reflected in the degree of improvement on height, of course, it should also include the effect on weight, reproductive function and bone development of children. (1) Effect on height It is indisputable that GnRHa treatment can effectively improve the adult height of children with CPP, and the effect of treatment is closely related to the age of treatment, and the younger the age of treatment, the more obvious the effect is. Allali et al. showed that the average adult height of children with CPP exceeded the predicted adult height by 2,2cm after treatment; and in the process of treatment, Lee et al. found that there was excessive growth deceleration in the children. There is excessive growth deceleration. (2) The effect on body weight Whether GnRHa treatment causes childhood obesity is still controversial, some scholars in the phenomenon of weight and BMI increase in some of the children after treatment was found, and the dosage and duration of treatment are different, the magnitude of weight gain is also different, Chiocca et al. found that GnRHa treatment may cause central obesity and hyperlipidemia. On the other hand, some scholars put forward the opposite opinion, they found that there was no significant increase in weight and BMI after GnRHa treatment in children with CPP through clinical observation, but there was a tendency for their FM to increase. The different genetic, family and socio-cultural backgrounds of the children may be one of the reasons for this disagreement. (3) Effects on bone development Although there is a transient decrease in bone density after GnRHa treatment, which can lead to osteoporosis and fracture, calcium supplementation can effectively improve this symptom. The reason for this is currently thought to be due to the inhibition of sex hormones by GnRHa, which in turn inhibits bone maturation. In addition, treatment does not affect long-term bone development. However, a recent study found that children with treated CPP had femoral head slippage, and the reason for this remains to be further investigated. (4) Effect on reproductive function GnRHa inhibits the gonadal axis, causing the sex hormone level to return to the pre-pubertal period, resulting in the cessation or even disappearance of gonadal development. However, in the course of GnRHa treatment, some children have vaginal bleeding, the incidence of which ranges from 5% to 9% or even 16% to 60% in different studies, especially in those who have already had their first menstrual period. The bleeding usually occurs 2 weeks after the first injection, and in a few cases it occurs after the second injection, and in some cases it is still present half a year later. In a small number of patients, it may even last as long as 11 to 13 d. It was previously thought to be a sex hormone withdrawal bleed. CPP leads to abnormal changes of many hormones in children's bodies, leading to the early initiation of puberty, thus affecting children's growth and development, especially in physical and sexual development, because children's growth and development are affected by many factors, among which endocrine hormones have a direct role, and the changes of neuroendocrine hormones in human body caused by CPP and its specific mechanism of action are still unclear, leading to the effects of CPP on human body and sexual development still exist. The effects of CPP on physical and sexual development are still questionable and need further study.