Irregular menstrual cycle strongly linked to deadly heart disease: study

According to a recent study published in the Journal of the American Heart Association, women with irregular menstrual cycles, either longer or shorter than the average range, may have a higher risk of certain heart problems, American Heart Association News reported quoting the latest study.

The research found that women whose menstrual cycles fell outside the typical 22- to 34-day range faced an increased cumulative risk of conditions such as coronary heart disease, heart attacks, and atrial fibrillation compared to women with cycles within that range.

Having a regular menstrual cycle length, which indicates the proper functioning of hormone systems connecting the hypothalamus, pituitary gland, and ovaries, is an important indicator of overall health. 

However, approximately 20% of women experience irregular cycle lengths.

Previous studies have already shown a connection between irregular menstrual cycles and risk factors for heart disease, such as insulin resistance, high cholesterol, high blood pressure, chronic inflammation, and polycystic ovarian syndrome. 

Some studies also suggest that hormonal fluctuations during the menstrual cycle can increase the risk of irregular heartbeats or arrhythmias.

Senior author Dr Huijie Zhang, who works at Nanfang Hospital of Southern Medical University in Guangzhou, China, highlighted the need to explore these risk factors given the increasing prevalence of heart disease and related mortality, particularly as 45% of women in Western countries are affected.

The study analyzed data from 58,056 women enrolled in the U.K. Biobank, a comprehensive health database in the United Kingdom, to investigate the association between menstrual cycle length and heart disease. 

The participants, with an average age of 46 and who had not yet reached menopause or had any cardiovascular disease at the start of the study, were followed up from 2006 to 2019.

During a median follow-up period of 11.8 years, the researchers discovered that women with irregular menstrual cycles had a 19% higher risk of developing cardiovascular disease, including coronary heart disease, heart attack, atrial fibrillation, stroke, and heart failure, compared to women with regular-length cycles. 

Specifically, shorter cycles were associated with a 29% increased risk of cardiovascular disease, while longer cycles were linked to an 11% higher risk.

When examining the risk for specific conditions, the study found that shorter cycles were associated with a 38% higher risk of atrial fibrillation, while longer cycles were connected to a 30% increased risk of the same condition. 

However, menstrual cycle length did not show an increased risk for stroke or heart failure.

Dr Zhang emphasised that their: "Analysis indicates women with menstrual cycle dysfunction may experience adverse cardiovascular health consequences." 

It should be noted, though, that the impact of menopause on menstrual cycle length could not be ruled out in this study, as the data primarily included women between the ages of 40 and 69. 

Additionally, since the study population consisted predominantly of white women, the findings may not be generalizable to women from diverse racial and ethnic backgrounds.

Nevertheless, the study's findings underscore the importance of monitoring menstrual cycle characteristics throughout a woman's reproductive life, according to Dr Zhang.