Irregular Menstrual Cycles May be a Marker of Heart Disease, Study Finds

If your periods don’t arrive every four weeks on the dot, you’re not alone. About 14% to 25% of people with uteruses in the U.S. experience irregular periods.

New research suggests this is something providers should consider paying more attention to in order to help screen for chronic conditions.

In an observational study published in JAMA in October, researchers noticed people who have irregular or prolonged menstrual cycles might have a higher risk of heart disease. Specifically, the risk of heart disease appeared higher in people who experienced cycles longer than 40 days—or in people who didn’t have periods at all.

While irregular menstrual cycles do not cause heart disease, it’s possible they serve as a marker of other health problems that ultimately contribute to heart disease—something the researchers hope to explore further in order to prevent them.

“From the perspective of preventive medicine, we are trying to identify people who are more likely to develop chronic diseases in their life,” Yixin Wang, MD, PhD, co-author of the study and research fellow at Harvard T.H. Chan School of Public Health, told Verywell.

How Much Do Menstrual Cycles Impact Heart Disease Risk?

To conduct the study, researchers collected data from over 80,000 women with an average age of 37.7 at the beginning of the study, who reported on their menstrual patterns since age 14. They completed follow-up questionnaires every two years for 24 years. The researchers looked at how long, on average, their menstrual cycles lasted and if they experienced coronary artery disease, heart attack, coronary revascularization (procedures to improve blood flow), or stroke during the course of the follow-up. 

While only 1,816 of the 80,630 participants ultimately developed heart disease before age 46, the results show a higher risk of heart disease among women who reported irregular cycles, no periods, or longer cycles.

Among People With Irregular or No Periods

Compared to those who reported regular cycles, participants with irregular cycles or no periods had between a 15% and 40% risk of heart disease. The risk appeared highest for those between the ages of 29 and 46.

Among People With Cycles Longer Than 40 Days

Compared to those who reported cycle lengths between 26 to 31 days, participants with longer periods had between a 30% and 44% higher risk of heart disease.

Why Might This Link Exist?

The connection between irregular menstrual cycles and heart disease isn’t totally clear. But Samar R. El Khoudary, PhD, a cardiovascular epidemiologist at the University of Pittsburgh who was not involved in this study, suggested hormones play a role. 

Specifically, when people experience changes in their menstrual cycle in their 20s and 30s, it’s usually related to dysfunction of hormones running between the brain and the pituitary gland. These hormonal changes can impact multiple body systems, including the cardiovascular system.

Additionally, El Khoudary said estrogen is a hormone that protects heart health. The longer the menstrual cycle, the less frequently a person ovulates and the less estrogen a person produces. Therefore, it’s possible that people with longer intervals between periods have less cardiovascular protection.

More Than Just Heart Disease

According to Wang, irregular menstrual cycles can be indicative of chronic diseases beyond heart disease. People with conditions such as polycystic ovary syndrome (PCOS) and endometriosis often experience atypical cycles. And the disrupted hormone function, increased blood pressure, and high cholesterol levels associated with these conditions may be responsible for an elevated risk of heart disease and cancers.

The new study corroborated findings from previous research suggesting lack of exercise, poor diet, smoking, and obesity are linked to irregular periods.

While Wang recommends speaking to a healthcare provider if you have erratic periods, striving for a regular period is not going to cure you of chronic illnesses. The best thing you can do is make healthy lifestyle choices.

El Khoudary agrees, explaining just how much lifestyle modifications can improve heart health.

“We know that if we can maintain a healthy lifestyle, including eating well, maintaining health, maintaining [a healthy] body weight, stopping smoking, and being physically active, we can eliminate up to 82% of the risk of heart disease later,” El Khoudary said. “The challenge is implementing and maintaining healthy lifestyles.”

By identifying risk factors of heart disease early and making lifestyle modifications, El Khoudary said it’s possible to minimize the impact of heart disease in the future.