Early menarche increases the risk of endometriosis.

The increase in endometriosis risk with early menarche is prominent in low-income countries.

Key Points

Importance:

• The trend of early sexual maturity in females has continued particularly in the last 20 years resulting in more serious health concerns associated with early menarche, including endometriosis.

Highlights:

• There is an increasing trend in the association between early menarche and endometriosis risk, and this risk is more pronounced specifically in low-income countries.

What's done here:

• Lu et al. from China aimed to see how different research populations, dates, and methodology affected estimating the risk of endometriosis in early menarche.
• A blind literature search using the terminology "endometriosis" and "early menarche" was performed between 2000 to May 2022.
• Meta-analyses and appropriate statistical evaluation were conducted to evaluate the relative risk of endometriosis, associated with early menarche.

Key Results:

• Sixteen studies that met the criteria were included.
• The meta-analyses revealed that the overall risk for endometriosis was increasing significantly with early menarche.
• Subgroup analyses showed a higher in studies after 2000, compared to the earlier studies. Furthermore, this increased risk was higher in low-income countries. 

Strength and limitations:

• The appropriate statistical methods and meta-analyses were the strength of this study.
• Limitations are the absence of the impact of race and ethnicity on early menarche age and the risk of endometriosis.
• The paucity of English literature from low-income countries may affect the results.

Lay Summary

Early menarche is the first menstrual bleeding occurring before 12 years of age. The timing of normal puberty in girls varies between nations due to genetic, socioeconomic, and environmental factors. Notably, the age of menarche decreased significantly in teenagers born after 2000 with the improvement in the socio-economic conditions in some populations.

Lu et al. from Shenzhen Baoan Women's and Children Hospital, Jinan University, Guangdong, China aimed to update the knowledge about the association between early menarche and endometriosis risk. For this purpose, the meta-analyses of published literature after 2000 were investigated to compare the age of menarche of women with or without endometriosis.

The authors performed a meta-analysis on 16 selected studies from the literature that met their criteria. Subgroup analyses, as well as sensitivity studies were also conducted to check the statistical performance.

The authors found that early menarche is associated with a significant risk of endometriosis.

Subgroup analyses revealed that this increased risk is higher in studies performed in the 21st century compared to the earlier studies. Furthermore, this increased risk was higher in low-income countries. 

The study was recently published in the journal named "Archives of Gynecology and Obstetrics".

Research Source: https://pubmed.ncbi.nlm.nih.gov/35377041/