A new study has revealed a significant link between cardiovascular disease and stroke risk in women who began menstruating before the age of 12. The study was published in the BMJ journal  Heart

Early age of menarche is one of many reproductive risk factors, including pregnancy, early menopause, and hysterectomy that have been associated with cardiovascular disease in later life. 

the researchers were data obtained from the UK Biobank-a large population-based study of more than half a million men and women up to the age of 69, who were recruited between 2006 and 2010-in an attempt to find potential associations.

The health condition of 267,440 women and 215,088 men, none of which had heart disease when they entered the study, was tracked up to March 2016 or whichever came first.

The average age of the women at the beginning of the study was 56, with 51% from the most affluent third of the UK population. Six out of 10 had never smoked.

The average age at which they had started having periods was 13; 85% had been pregnant and 44% had at least two children. The average age at which they had their first child was 26.

During the study's monitoring period that spanned for 7 years, 9054 cases of heart disease were recorded. The total included 5782 cases of coronary artery disease and 3489 cases of stroke, which comprised 28% and 43% of women respectively.

The results of the data analysis indicated that women who had periods before the age of 12 were at 10% increased risk of heart disease when compared to those who had been 13 years or older.

Likewise, women who had undergone early menopause had a 33% heightened risk of heart disease, and 42% increased risk of stroke, after taking other potentially influential factors into account.

Previous miscarriages were linked to increased risk of heart disease, with each miscarriage increasing the risk by 6%. Stillbirth also increased the risk of heart disease by 22% and stroke by (44%).

Another risk factor was young age at first parenthood, with each additional year of age reducing the risk of heart disease by around 3%. But the similarity in link between the number of children and heart disease for men and women is that they are less important than the social, psychological, and behavioral ones.

Since this is an observational study, there were no firm conclusions about cause and effect. In addition, the information on reproductive factors was based on recall and the results may not have been accurate. However, the study was large and the researchers were able to account for a range of factors that might have skewed the data.

The following authors commented: "More frequent cardiovascular screening would seem to be sensitive among women who are early in their reproductive cycle, or who have a history of adverse reproductive events or a hysterectomy, as this might help to delay or prevent their onset of cardiovascular disease. "