性早熟的患病率难以估计,但有报道称为1/5 000。[3]Cesario SK, Hughes LA. Precocious puberty: a comprehensive review of literature. J Obstet Gynecol Neonatal Nurs. 2007;36:263-274.http://www.ncbi.nlm.nih.gov/pubmed/17489932?tool=bestpractice.com 促性腺激素依赖性性早熟(GDPP)或中枢性性早熟在女孩发生率10倍于男孩。[3]Cesario SK, Hughes LA. Precocious puberty: a comprehensive review of literature. J Obstet Gynecol Neonatal Nurs. 2007;36:263-274.http://www.ncbi.nlm.nih.gov/pubmed/17489932?tool=bestpractice.com[4]Bridges NA, Christopher JA, Hindmarsh PC, et al. Sexual precocity: sex incidence and aetiology. Arch Dis Child. 1994;70:116-118.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1029712/pdf/archdisch00562-0040.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/8129431?tool=bestpractice.com[5]Pescovitz OH, Comite F, Hench K, et al. The NIH experience with precocious puberty: diagnostic subgroups and response to short-term luteinizing hormone releasing hormone analogue therapy. J Pediatr. 1986;108:47-54.http://www.ncbi.nlm.nih.gov/pubmed/3080571?tool=bestpractice.com 这可能与女孩低水平的促性腺激素释放激素即可激活下丘脑-垂体-性腺轴有关。[6]Stanhope R, Brook CG, Pringle PJ, et al. Induction of puberty by pulsatile gonadotropin releasing hormone. Lancet. 1987;2:552-555.http://www.ncbi.nlm.nih.gov/pubmed/2887840?tool=bestpractice.com 在美国,诊断性早熟的女孩数量在增加。[3]Cesario SK, Hughes LA. Precocious puberty: a comprehensive review of literature. J Obstet Gynecol Neonatal Nurs. 2007;36:263-274.http://www.ncbi.nlm.nih.gov/pubmed/17489932?tool=bestpractice.com
几个因素影响青春期开始的年龄,虽然它主要遵循家族模式。 已知母女的青春期开始年龄相似,尤其是月经初潮年龄。 但是,这个过程可被环境因素、种族及慢性疾病所影响。
长期趋势表明,女孩的初潮年龄在过去的一个世纪明显下降,尤其在西方国家,[7]Tanner JM. Trend towards earlier menarche in London, Oslo, Copenhagen, the Netherlands and Hungary. Nature. 1973;243:95-96.http://www.ncbi.nlm.nih.gov/pubmed/4706636?tool=bestpractice.com[8]Biro FM, Khoury P, Morrison JA. Influence of obesity on timing of puberty. Int J Androl. 2006;29:272-277.http://www.ncbi.nlm.nih.gov/pubmed/16371114?tool=bestpractice.com 虽然在过去的40年没有进一步改变。荷兰最近的研究提出青春期初始年龄趋于稳定。[9]Delemarre-van de Waal HA. Secular trend of timing of puberty. Endocr Dev. 2005;8:1-14.http://www.ncbi.nlm.nih.gov/pubmed/15722614?tool=bestpractice.com 较少证据表明,男童青春期初始年龄已随时代改变。[10]de la Puente ML, Canela J, Alvarez J, et al. Cross-sectional growth study of the child and adolescent population of Catalonia (Spain). Ann Hum Biol. 1997;24:435-452.http://www.ncbi.nlm.nih.gov/pubmed/9300121?tool=bestpractice.com[11]Mul D, Fredriks AM, van Buuren S, et al. Pubertal development in The Netherlands 1965-1997. Pediatr Res. 2001;50:479-486.http://www.ncbi.nlm.nih.gov/pubmed/11568291?tool=bestpractice.com 其可能原因是与女孩初潮的文件记录相比,男孩青春期开始和完成的时间无较明确的定义和文件记录。
同白种人女孩(月经初潮平均年龄为12.9岁)相比,黑种人女孩(月经初潮平均年龄为12.2岁)较早进入青春期。[12]Himes JH. Examining the evidence for recent secular changes in the timing of puberty in US children in light of increases in the prevalence of obesity. Mol Cell Endocrinol. 2006;254-255:13-21.http://www.ncbi.nlm.nih.gov/pubmed/16759793?tool=bestpractice.com 在美国自1960年到1990年,白种人女童月经初潮平均年龄提前3个月,而黑种人女童月经初潮年龄提前5.5个月。[12]Himes JH. Examining the evidence for recent secular changes in the timing of puberty in US children in light of increases in the prevalence of obesity. Mol Cell Endocrinol. 2006;254-255:13-21.http://www.ncbi.nlm.nih.gov/pubmed/16759793?tool=bestpractice.com
社会经济地位的改善,健康保健,营养状态及移民均可影响遗传倾向和长期趋势。 儿童肥胖的发生率自1980年以来增加了一倍。[13]Ogden CL, Carroll MD, Flegal KM. High body mass index for age among US children and adolescents, 2003-2006. JAMA. 2008 May 28;299(20):2401-5.http://jama.jamanetwork.com/article.aspx?articleid=1028638http://www.ncbi.nlm.nih.gov/pubmed/18505949?tool=bestpractice.com 中度肥胖与月经初潮年龄提前相关。[8]Biro FM, Khoury P, Morrison JA. Influence of obesity on timing of puberty. Int J Androl. 2006;29:272-277.http://www.ncbi.nlm.nih.gov/pubmed/16371114?tool=bestpractice.com[14]Osler DC, Crawford JD. Examination of the hypothesis of a critical weight at menarche in ambulatory and bedridden mentally retarded girls. Pediatrics. 1973;51:675-679.http://www.ncbi.nlm.nih.gov/pubmed/4697516?tool=bestpractice.com 化妆品及食物中雌激素成分也可导致青春期年龄提前;在部分地区,“流行性”乳房早发育可能与环境中的雌激素暴露有关。[15]Massart F, Parrino R, Seppia P, et al. How do environmental estrogen disruptors induce precocious puberty? Minerva Pediatr. 2006 Jun;58(3):247-54.http://www.ncbi.nlm.nih.gov/pubmed/16832329?tool=bestpractice.com