A new study conducted by Su-Min Jeong and team showed that after controlling for conventional cardiovascular risk variables, menarche later than the mean age at menarche (13 years old) and oral contraceptives (OC) usage (1 year) were linked to a greater risk of cardiovascular diseases (CVD). the findings of this study were published in European Journal of Preventive Cardiology.
The risk factors of cardiovascular disease (CVD) among Korean premenopausal women have not been well studied, despite the rising morbidity and mortality of cardiovascular illnesses in young women. In order to ascertain how age of menarche and other female reproductive characteristics relate to the risk of CVD in premenopausal women, this study was carried out.

There were 1,088,992 premenopausal women included who underwent health screening in 2009. Myocardial infarction (MI) and ischemic stroke were the study's outcomes. Traditional CVD risk factors and reproductive factors were adjusted during the Cox proportional hazards regression analysis.
The key findings of this study were:
1. The average age was 43.8 5.3 years (98.9%, 55 years), 3.5% of the participants were current smokers, and 1.2% were strong drinkers.
2. There were 10,876 CVD events (1.0 per 1000PY) during a mean follow-up of 8.3 years (9,032,685.9 PY). The risk of CVD increased with later menarche; 12 years (adjusted hazard ratio 1.04, 95% confidence interval 0.93-1.16), 13 years (reference), 14 years (1.06, 0.98-1.14), 15 years (1.15, 1.07-1.24), 16 years (1.23, 1.14-1.3 (1.33, 1.24–1.44).
3. Oral contraceptives (OC) users (1 year) had a higher risk of CVD (1.11, 1.01-1.22) (P for trend = 0.007) than non-users.
In conclusion, the reason for this variation by age group is unknown, however it shows that menarcheal age may be related to CVD risk by age group. It is likely that age at menarche influences estrogen levels in premenopausal women in their 30s. Women with early menarche exhibited greater blood estradiol concentrations and lower serum sex hormone-binding globulin concentrations than women with later menarche, suggesting that they may be more resistant to CVD events. Female reproductive variables may be regarded distinct risk factors for CVD in premenopausal women, even if the absolute cardiovascular risk is modest, according to this study.
Reference:
Jeong, S.-M., Jeon, K. H., Jung, W., Yoo, J. E., Yoo, J., Han, K., Kim, J. Y., Lee, D.-Y., Lee, Y.-B., & Shin, D. W. (2022). Association of reproductive factors with cardiovascular disease risk in premenopausal women: nationwide population-based cohort study. In European Journal of Preventive Cardiology. Oxford University Press (OUP). https://doi.org/10.1093/eurjpc/zwac265