An earlier first birth, a higher live birth rate and starting periods at a younger age are all linked to a higher risk of cardiovascular problems in women, according to new research.
The study is the most comprehensive analysis to date of reproductive factors specific to women and their association with a range of cardiovascular diseases, including atrial fibrillation (irregular heartbeat), coronary heart disease, heart failure and stroke. The researchers hope it will help doctors better understand and monitor women’s risk factors and intervene where necessary.
Researchers from Imperial’s National Heart & Lung Institute, University of Cambridge and Yale School of Public Health analyzed genetic data related to women’s age at first birth, their number of live births, their age at their first menstrual period (menarche), and their age at menopause. They looked at previous studies involving more than 100,000 women.
Observational research has previously shown that some reproductive factors are associated with cardiovascular disease in women later in life, but such studies are limited as they have been unable to support a causal relationship.
By using a statistical technique called Mendelian randomization, the researchers were able to show a link between the genes that predict reproductive factors and the risk of multiple cardiovascular diseases. This type of analysis allows researchers to cut through the noise of factors such as diet, economic background and physical activity levels that might otherwise complicate the overall picture, and thus points to causal relationships.
The analysis found that an earlier first birth, a higher number of live births and an earlier menarche were associated with a higher risk of atrial fibrillation, coronary artery disease, heart failure and stroke in women. However, it found no association between age of menopause and cardiovascular disease.
The researchers also found that much of the increased risk of earlier menarche was due to the fact that this factor was associated with women having a higher body mass index (BMI). This means that lowering a person’s BMI can help reduce this risk. The increased risk of a preterm first birth could be partly mitigated by acting on traditional cardiometabolic risk factors, such as BMI, high cholesterol and high blood pressure.
Dr. Maddalena Ardissino, lead author of the study, from the National Heart and Lung Institute at Imperial College London, said: “Women are often mischaracterized as being at low risk of cardiovascular disease, leading to delays in diagnosis. Even when they are diagnosed, they usually receive less targeted treatment than men.
“This study shows a clear link between reproductive factors and cardiovascular disease. This does not mean that women should be concerned if they started their period at a young age, or if they had an early first birth. Our research shows that “The additional risk of cardiovascular disease can be minimized if traditional risk factors such as BMI and blood pressure are well controlled. These findings highlight the need for physicians to closely monitor these risk factors in women and intervene where necessary.”
Dr. Fu Siong Ng, senior author of the study, from the National Heart and Lung Institute at Imperial College London, said: “Many of the previous studies on cardiovascular disease have focused on men, but our research shows that gender-specific factors are.” affecting the risk for women.
“While we can’t say exactly how much these factors increase the risk of cardiovascular disease, our research shows that reproductive history is important and points to a causal effect. We need to understand more about these factors to ensure that women get the best possible get.” concern.”
Further research is needed to understand the magnitude of the relationship between reproductive factors and cardiovascular disease risk, for example whether there is a linear or non-linear relationship between a factor and increased risk.
Cardiovascular diseases are often seen as a man’s disease, because men are more likely to get them at a younger age than women. However, this group of diseases poses a serious problem for women.
Research by the British Heart Foundation has shown that coronary artery disease kills more than twice as many women as breast cancer in the UK each year, with more than 800,000 women in the UK living with the disease. It is also estimated that around 380,000 women currently living in the UK have survived a heart attack.
Dr. Sonya Babu-Narayan, Associate Medical Director at the British Heart Foundation and consultant cardiologist, said: “The misconception that cardiovascular disease mainly affects men costs women their health and even their lives.
“It is critical that women are empowered with the knowledge of what could put them at a higher risk of developing heart disease or stroke in the future. This includes the known risks that affect everyone – but for women there may be additional risk factors from their reproductive years to add to the list.
“If we want to save more women’s lives, asking about menstruation and pregnancy should be routine when assessing every woman’s risk of heart disease and stroke.”
The study was supported by funding from the British Heart Foundation, the Medical Research Council and the National Institute for Health Research.