Secular trends of age at menarche and the effect of famine exposure on age at menarche in rural Chinese women

Abstract

Background

Over the past few decades, more studies have suggested that the age at menarche (AAM) has continued to decline. However, the AAM for women in resource-constrained areas is not clear. Moreover, the association between the Chinese famine and AAM is still unclear in rural regions.

Aim

The study aimed to investigate the secular trends of AAM for women born between 1935 and 2000 and to further explore the effect of famine on AAM in rural China.

Subjects and methods

The study included 23,444 women participants from the baseline study of the Henan Rural Cohort study. Changing AAM over time was analysed using linear regressions. Multinomial logistic regression was conducted to analyse the association between famine exposure and AAM subgroups.

Results

The age-standardised mean AAM was 14.74 years. The average AAM declined from 16.98 years for those born in 1935 to 13.87 years for those born in 2000, a decline of 0.077 years per 1 year and 0.729 years per decade. Compared to the reference group, women exposed to famine during foetal, early childhood, middle childhood, and late childhood were 1.376 (95% CI = 1.071–1.769), 1.848 (95% CI = 1.512–2.259), 2.084 (95% CI = 1.725–2.518), and 2.146 (95% CI = 1.788–2.576) times more likely to be ≥18 years AAM than women unexposed to famine, respectively.

Conclusion

AAM showed a decreasing trend in rural China. Furthermore, both foetal and childhood famine exposure, especially in late childhood, were positively associated with increased AAM compared to unexposed famine.

Keywords:

• Age at menarche
• Chinese famine
• secular trends
• rural population

Ethics approval

Ethics approval was obtained from the Zhengzhou University Life Science Ethics Committee, and written informed consent was obtained for all participants. Ethic approval code: [2015] MEC (S128).

Acknowledgements

The authors thank all of the participants, coordinators, and administrators for their support during the research. In addition, the authors would like to thank Tanko Abdulai for his critical reading of the manuscript.

Clinical trial registration

The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015–07-06. http://www.chictr.org.cn/showproj.aspx?proj=11375

Disclosure statement

All authors have read and approved this version of the article, and declared that they have no competing or financial interests to disclosure.

Data availability statement

The raw data supporting the conclusions of this manuscript will be made available by the authors, without undue reservation, to any qualified researcher.

Additional information

Funding

This research was supported by the Foundation of National Key Program of Research and Development of China [Grant NO: 2016YFC0900803], The Science and Technology Innovation Team Support Plan of Colleges and Universities in Henan Province [Grant NO: 21IRTSTHN029], Key Research Program of Colleges and Universities in Henan Province [Grant NO: 21A330007], Discipline Key Research and Development Program of Zhengzhou University [Grant NO: XKZDQY202008, XKZDQY202002]. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.