Study Objective

To assess emergent changes in the age at menarche and investigate associated factors in Israeli adolescents in 2003 and 2016.

Design

Cross-sectional study.

Setting

Two national representative school-based surveys (first and second “Mabat Youth”).

Participants

Both surveys included female students in 7th-12th grades (ages 11-19 years). The first (N = 3328) was conducted between the years 2003 and 2004, and the second (N = 2535) from 2015 to 2016.

Interventions

The survey questionnaire was self-administered and anthropometric measurements were performed by trained personnel.

Main Outcome Measures

The current age at menarche in Israeli girls was determined and independent factors (demographic, clinical, and lifestyle) examined. Changes that occurred since the past national survey more than a decade ago were documented.

Results

The estimated median age at menarche declined from 13.0 (interquartile range, 12.0-14.0) years in 2003-2004 to 12.5 (interquartile range, 12.0-13.0) years in 2015-2016 (P < .0001). Jewish girls reached menarche earlier than Arab girls, but both populations experienced a similar downward trend in the past approximately 14 years. Greater body mass index, higher socioeconomic status, and immigrant status were associated with younger menarche onset (P < .001). Age at menarche remained lower in 2015-2016 vs 2003-2004, even after adjustment for these potential confounders, with a high hazard ratio (HR), which decreased as a function of survival time (t): HR_t = 15.417 × 0.813^t.

Conclusion

This study confirms the decline in age at menarche in Israel. Findings were associated with body mass index and population group but also indicated that other factors are likely involved.

中文翻译：

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初潮初潮：2003年和2016年两次以色列青年全国调查的结果。

研究目标

评估初潮年龄的新变化并调查2003年和2016年以色列青少年的相关因素。

设计

横断面研究。

设置

两项全国代表性的校本调查（第一次和第二次“ Mabat青年”）。

参加者

两项调查均包括7至12年级（11至19岁）的女学生。第一次（N = 3328）在2003年至2004年之间进行，第二次（N = 2535）在2015年至2016年之间进行。

干预措施

该调查问卷是自行管理的，并且由受过培训的人员进行人体测量。

主要观察指标

确定了以色列女孩目前的初潮年龄，并检查了独立因素（人口统计学，临床和生活方式）。记录了自十多年前的上一次全国调查以来发生的变化。

结果

初潮的估计中位年龄从2003-2004年的13.0（四分位间距，12.0-14.0）岁下降到2015-2016的12.5（四分位间距，12.0-13.0）岁（P  <.0001）。犹太女孩的初潮早于阿拉伯女孩，但是在过去约14年中，这两个族群的经历了类似的下降趋势。更高的体重指数，更高的社会经济地位和移民地位与年轻的初潮发病有关（P  <.001）。即使对这些潜在的混杂因素进行了调整，2015-2016年的初潮年龄仍比2003-2004年低，具有较高的危险比（HR），其随着生存时间（t）的变化而降低：HR _t  = 15.417×0.813 ^t。

结论

这项研究证实了以色列初潮年龄的下降。调查结果与体重指数和人群有关，但也表明可能涉及其他因素。