Current pubertal development in Chinese children and the impact of overnutrition, lifestyle and perinatal factors

<strong>Context: </strong>Pubertal onset has been decreasing in many countries but there has been no data on pubertal development in Chinese children over the last decade. <strong>Objective: </strong>The primary objective of the study was to evaluate the current status of sexual maturation in Chinese children and adolescents. Secondary objectives were to examine socio-economic, lifestyle and auxological associations with pubertal onset. <strong>Design: </strong>A national, cross-sectional health survey. <strong>Setting: </strong>The community-based setting. <strong>Participants: </strong>A multistage, stratified cluster random sampling method was used to select a nationally representative sample, consisting of 231,575 children and adolescents(123,232 boys and 108,343 girls) between 2017 and 2019. <strong>Main Outcome Measure: </strong>Growth parameters and pubertal staging were assessed by physical examination. <strong>Results: </strong>Compared to 10 years previously the median age of Tanner 2 breast development and menarche were similar at 9.65 years and 12.39 years respectively. However, male puberty occurred earlier with a median age of testicular volume ≥4 ml of 10.65 years. Pubertal onset did occur earlier at the extremes with 3.3% of the girls with breast development between 6.5-6.99 years old increasing to 5.8% by 7.5-7.99 years old. Early pubertal onset was also noted in boys, with a testicular volume ≥ 4 ml noted in 1.5% between 7.5-7.99 years increasing to 3.5% between 8.5-8.99 years old. Obesity and overweight increased the risk of developing earlier puberty compared to the normal weight in both boys and girls. <strong>Conclusions: </strong>Over the past decade, pubertal development is occurring earlier in Chinese children. While the cause is multifactorial, overweight and obesity are associated with earlier puberty onset. The currently-used normative pubertal data of precocious puberty may not be applicable to diagnose precocious puberty.研究背景：近十余年来，多国报道青春期启动年龄呈提前趋势，但目前尚无近十年中国儿童青春期发育状况的相关数据。 研究目的：本研究首要目标为评估当前中国儿童青少年的性成熟现状；次要目标为探究青春期启动与社会经济因素、生活方式及体格发育指标的关联。 研究设计：全国性横断面健康调查。 研究现场：以社区为调查场景。 研究对象：采用多阶段分层整群随机抽样(multistage stratified cluster random sampling)方法，选取2017-2019年间具有全国代表性的样本，共纳入231575名儿童青少年（其中男童123232名，女童108343名）。 主要结局指标：通过体格检查评估生长参数及坦纳(Tanner)青春期分期情况。 研究结果：与十年前相比，女性坦纳2期乳腺发育的中位年龄（9.65岁）与月经初潮中位年龄（12.39岁）基本持平；但男性青春期启动提前，睾丸体积≥4毫升的中位年龄为10.65岁。极端年龄组的青春期启动年龄确实有所提前：6.5~6.99岁年龄段出现乳腺发育的女童占比为3.3%，至7.5~7.99岁年龄段该占比升至5.8%；男童中也观察到青春期提前现象，7.5~7.99岁年龄段睾丸体积≥4毫升的占比为1.5%，至8.5~8.99岁年龄段该占比升至3.5%。与体重正常人群相比，超重与肥胖会增加男童女童出现青春期提前的风险。 研究结论：过去十年间，中国儿童的青春期发育呈现提前趋势。尽管其成因是多因素的，但超重与肥胖与青春期启动提前存在显著关联。当前使用的性早熟诊断参考标准数据可能不再适用于中国儿童的性早熟诊断。