Abstract: Objective　To investigate the age of menarche in adolescent girls，and to explore the association between BMI and the age at menarche.Methods　A total of 534 adolescent girls（10-19 years old） were randomly selected and investigated from Central Shaanxi，Southern Shaanxi and Northern Shaanxi from July to August 2007.The items of the questionnaire included general data（age，year of education），family background（family size，family income source），physical examination（height，body mass，etc.） to analyze the age distribution of menarche in adolescent maidens.According to the standard of American Center for Disease Control and Prevention（CDC），the BMI of adolescent girls was classified into low body mass（BMI<5%），normal body mass（5%≤BMI<85%），and high body mass（85%≤BMI<95%）.Multivariate Logistic regression analysis was used to analyze the relationship between menarche and BMI.Results　Among the 534 adolescent girls，446 cases（83.5%） had menarche，and 88 cases（16.5%） did not have menarche.The menarche age and its distribution among adolescent girls between rural and urban areas were statistically significant（P<0.05）.The menarche age of adolescent girls in Northern Shaanxi was older than Central Shaanxi and Southern Shaanxi（P<0.05）.The distribution of menarche at age among adolescent girls was statistically significant in different body masses（P<0.05）.The results of multivariate Logistic regression analysis presented that low body mass was positively associated with the age of menarche before and after adjusting the age，area and family background（P<0.05）.The risk of not having menarche increased by 11.39 times in low body mass group compared with normal body mass group.There was a positive correlation between high body mass and the menarche age before adjusting the age，area and family background（P<0.05）.There wasn't a positive correlation between high body mass and the menarche age after adjusting the age，area and family background（P>0.05）.Conclusion　The age of menarche in adolescent girls in Shaanxi province is significantly different between different regions or urban-rural areas.The menarche age of girls are related with their BMI，and the menarche age can be delayed due to lower BMI.

Key words: Puberty, Menarche, Body mass index

摘要： 目的　了解陕西省青春期少女的月经初潮年龄现状及其与BMI的关系。方法　选取2007年7—8月陕西省关中、陕南、陕北地区营养与健康生物学调查中处于青春期的少女（10~19岁）534例为调查对象，采用自行设计的调查问卷进行面对面调查。问卷内容包括：一般资料（年龄、受教育年限）、家庭背景（家庭人口数、家庭收入来源）、体格检查（身高、体质量等），分析青春期少女的月经初潮年龄分布情况。根据美国疾病预防控制中心（CDC）标准按年龄别百分位数对BMI进行分类：低体质量（BMI<5%）、体质量正常（5%≤BMI<85%）、超重（85%≤BMI<95%）。采用多因素Logistic回归分析分析月经初潮与BMI的关系。结果　534例青春期少女中已来月经初潮的446例（83.5%），未来月经初潮的88例（16.5%）。农村和城区已来月经初潮的青春期少女月经初潮年龄及其分布情况比较，差异均有统计学意义（P<0.05）。陕北已来月经初潮的青春期少女月经初潮年龄大于关中、陕南（P<0.05）。不同体质量已来月经初潮的青春期少女月经初潮年龄分布情况比较，差异有统计学意义（P<0.05）。多因素Logistic回归分析结果显示，校正前低体质量与是否来月经初潮呈正相关（P<0.05）；当校正了年龄、城乡和家庭背景因素后，低体质量与是否来月经初潮呈正相关（P<0.05），与体质量正常者相比，低体质量者不来月经初潮的风险增加11.39倍。校正前超重与是否来月经初潮呈正相关（P<0.05）；校正年龄、城乡和家庭背景因素后，两者无相关性（P>0.05）。结论　陕西省青春期少女的月经初潮年龄在不同地区和城乡间存在显著差异，月经初潮年龄的早晚与其BMI的大小有关联，BMI过小青春期少女的月经初潮年龄有延后的趋势。

关键词: 青春期, 月经初潮, 人体质量指数