Premature puberty (PP) in children is divided into central precocious puberty (CPP) and peripheral precocious puberty (PPP) according to whether HPGA is initiated early. The clinical characteristics of CPP are that growth and development mismatch with age, bone age exceed chronological age, and the levels of sex hormones are abnormal. In this study, 187 children were tested for age, height, bodyweight, BMI, bone age, and sex hormone levels, the results showed that height, bodyweight, bone age, LH, FSH, and estradiol were higher in 52 children with CPP than those in non-precocious puberty children. These clinical manifestations were consistent with the diagnostic criteria of CPP in children.
In our research, overweight was an independent risk factor for CPP in children (OR=2.383), the same result was found in the previous study. It may be that energy balance and HPGA modulate some common neuroendocrine regulatory factors, such as leptin, adrenaline, neuropeptide. In terms of the global, the incidence of overweight and obesity in children is increasing year by year, the age of puberty is earlier and the duration is getting shorter and shorter. Early and reasonable weight control not only improves children’s physical and mental health but also cultivates good social relationships. Parents should pay more attention to their children’s weight changes, actively improve living habits and eating habits, make detailed and personalized dietary and exercise plans. It is necessary to ensure that children receive essential nutrients but avoid obesity, parents realize the importance of physical examination in children’s growth and development.
In addition, the results in our study showed that the risk of CPP in children who used electronic products for a long time (＞7 h/w) was 1.13 times higher than that of short-term users. Long-term use of electronic equipment was a risk factor of CPP in children (OR=0.042). It was demonstrated that the light from electronic products such as TV, computer, mobile phone, phone watch can significantly reduce the levels of melatonin, weaken the inhibition on gonads, so as to induce the occurrence of CPP. Therefore, for parents, overusing electronic products instead of themselves to accompany children may not be the best choice. They should make scientific guidance and appropriate intervention in children’s use of electronic products, encourage and support children to participate in various outdoor activities, and cultivate their self-control and self-management ability.
The occurrence of CPP in children was closely related to whether they like sweets (OR=12.400) or fried food (OR=8.696), which is similar to the results of Yu et al. Sweets and fried foods often contain some additives such as thickeners, emulsifiers, baking powder, puffing agents, which have low nutrition but high energy. Bingeing is prone to induce obesity, unbalanced diet and severe food preference. It not only affects digestion and absorption, triggering diabetes, cardiovascular disease, cancer, but also produces the early appearance of secondary sex characteristics. Hence, parents should reasonably control the children’s diet, try not to eat high salt, animal fat, red meat, sugar-sweetened drinks, low fiber vegetables; conversely, exercise, low-calorie diet, vegetables, fruit, legume, and fish are conducive to maintain the balance between hygiene and nutrition, and provide the necessary dietary nutrition for children’s growth and development. Besides, according to the nomogram, another diet-related risk factor was the intake of carbonated soft beverages (＞500 ml/w, OR=15.816). Carbonated soft beverages are mainly composed of additives and preservatives, such as artificial colors, methylparaben, propylparaben, and sugar. When these endocrine disruptions accumulate in the body to a certain extent, they will produce estrogen-like activity, resulting in the advancement of normal menstrual cycle. Furthermore, a large amount of carbonated soft drinks not only increase the risk of dental caries and gastrointestinal damage, but also affect the absorption of vitamins, minerals, and other nutrients, which has become one of the most important factors in hindering the growth and development of children. Therefore, it is necessary for parents to guide children to drink enough water and milk instead of milk beverages.
The calibration curve showed good consistency in the risk prediction model. We used AUC to quantify the model predictive performance. AUC＞0.9 indicates high accuracy; 0.7-0.9, medium accuracy; 0.5-0.7, low accuracy. In our study, AUC of the risk prediction model was 0.874, the sensitivity was 0.852, and the specificity was 0.769, which indicated that this model could be used to predict and identify CPP in children. Parents and caregivers can systematically assess children’s development, living and eating habits based on our risk prediction model, and then formulate a prospective health guidance program, and implement targeted early interventions measures for children.