摘要目的 调查中国九大城市男孩青春发育的平均年龄.方法 采用全国协作性横向调查,于2003-2005年间进行.对象为代表中国东、西、南、北、中部地区的九大城市(包括北京、天津、青岛、上海、武汉、南宁、重庆、广州、福建)城区3-19.83岁的19 054名健康男孩.用睾丸计(Preder orchidometer)测量睾丸容积(ml);通过视诊法进行阴毛发育Tanner分期;发放调查表,由家长和(或)男孩本人填写遗精与否及具体日期.采用概率单位回归法(Probit analysis)计算睾丸发育、阴毛发育和首次遗精的平均年龄及95%可信区间(CI).以睾丸容积4 ml作为青春期启动的标志.将本次调查结果 与国内外文献报道的结果 相比较,并将首次遗精(初遗)年龄与1979年以来进行的五次全国性学生体质健康调查中的相似人群的初遗年龄进行比较.结果 9岁组12.99%的男孩睾丸发育已达4 ml.中国男孩青春期启动的中位年龄是10.55(95% CI 10.27～10.79)岁.阴毛发育Ⅱ期的中位年龄是12.78(95% CI 12.67～12.89)岁,首次遗精的中位年龄是14.05(95% CI 13.80～14.32)岁.1979年以来,中国城区男孩初遗年龄呈现年代提前的变化.结论 中国大城市城区男孩睾丸发育年龄较目前临床所用正常值早,并属当今睾丸青春发育较早、阴毛发育较迟的人群之列;自1979年以来,以呈现首次遗精为特征的性成熟年龄呈年代提前趋势.

abstractsObjective There is a trend that puberty is starting earlier in the 21st century,which is primarily based on studies of girls.The assessment of pubertal stages in the individual child is useful only if recent and reliable reference data from the same population are available for comparison.However,nationally representative pubertal data for Chinese boys in China are lacking.The aim of this study was to investigate the current pubertal development in healthy urban Chinese boys.Method A cross-sectional study of the pubertal development of a sample of 19 054 urban Chinese boys aged 3-19.83 years was conducted between 2003 and 2005.Testicular volume was determined with a Prader orchidometer.Pubic hair development Was assessed according to the Tanner method.Data on spermarche were collected by the status quo method.Probit analysis was used to calculate the median age and 95% CI for onset of testicular and pubic hair development and spermarche.A testicular volume greater than or equal to 4 ml was taken as a definite sign of the onset of puberty.Mean ages for sexual development in boys were compared with other published series,while the spermarcheal age was compared to those in the similar population of the five National Surveys on Students Constitution and Hesith undertaken since 1979 in China.Result At the age of 9 years.12.99% of the boys had a testicular volume 4 ml or more.The median age of onset of puberty as indicated by a testicular volume of 4 ml or more was 10.55(95% CI 10.27-10.79)years.The median age for onset of pubic hair development(PH2)and spermarche was 12.78(95% CI 12.67-12.89)years and 14.05(95% CI,13.80-14.32)years,respectively.There was a highly significant downward secular trend for spermarcheal age of Chinese boys since 1979.Conclusion Pubertal onset as indicated by testicular development in urban Chinese boys is earlier than currently used norms.Age of testicular development is among the earliest medians recorded in the world population.while onset of pubic hair development is among the oldest ones.Secular downward change of sexual maturation as indieated by initiation of spermarche has been significant since 1979.