Can Your Period Predict Heart Disease? (Episode 632)

Full Transcript: Episode 632

Lisa Hendrickson-Jack:

You’ve heard me say many times that the menstrual cycle is a vital sign and we should be paying attention to it. And in today’s episode, we are delving into a fairly new study that is solidifying this piece of information in very significant ways.

The paper that we’ll be talking about today is specifically looking at the association between menstrual cycle characteristics and cardiometabolic outcomes in later life. Let’s go ahead and jump into today’s episode.

The study that we will be looking at today was first published in 2023. It’s a really interesting and compelling study because of how much data it’s putting together. What the researchers did is they followed over 700,000 women over a period of about 26 years, from 1995 to 2021.

This is a significant data set. These researchers were specifically looking at the potential link between menstrual cycle characteristics and cardiometabolic health. They were specifically looking at cardiovascular disease, ischemic heart disease, heart failure, and cerebrovascular disease and or stroke.

We’re going to go through some of the most interesting aspects of the study, some of the findings that really stood out to me. The first one I wanted to talk about is that when the major cardiovascular disease risk guidelines were determined, the menstrual cycle was actually left out as a major risk factor for women.

If I quote from the paper itself: recent literature reviews and consensus statements from professional societies in the US and Europe have highlighted the association between female reproductive factors and risk of cardiovascular disease in later life. However, menstrual cycle history and its relation to cardiovascular disease was not included despite evidence of its association with cardiovascular disease risk.

This is really interesting because even though there is a significant association between the menstrual cycle specifically and cardiovascular risk, bodies that make all these decisions have not formally included menstrual cycle characteristics as one of the risk factors. These researchers are pushing back and saying, look, we just analyzed this massive data set and this is a really significant risk factor that we should not be ignoring.

We can add some background information to this. Cardiovascular disease is the leading cause of death in women worldwide, accounting for 35% of total female deaths. This is a very significant issue, and it’s been an issue because women present differently with different types of symptoms than men do.

For many years, there’s been a push to ensure that women are accurately represented in the literature. It’s not a surprise to me that the menstrual cycle hasn’t been formally included. But it is really exciting to see research actively addressing these issues and researchers pushing to have this information included.

As we know, when women are typically going to the doctor and presenting with abnormal or irregular menstrual cycles, these issues are thought of as exclusively reproductive issues or fertility issues. We’re not necessarily linking these issues to potential future cardiometabolic issues.

This paper was written before the recent change in the designation for PCOS. The name has now officially been changed to PMOS to reflect the metabolic issues associated with PCOS. And of course, one of the hallmark characteristics of PCOS are long and irregular menstrual cycles.

This cohort of over 700,000 women between the ages of 18 and 40 is one of the largest data sets ever used to examine the question of whether the menstrual cycle is linked to cardiovascular disease.

What the researchers determined with their analysis is that irregular cycles raise the risk of type 2 diabetes by 37% and heart failure by 30%. These are not new findings. This study just more firmly establishes them. With such a large data set, the data becomes impossible to ignore — they can’t say the study wasn’t designed well enough or the sample size wasn’t large enough.

It’s not groundbreaking new information that women who have long and irregular cycles have a significantly higher risk of diabetes or heart failure. These connections have already been established. But this really does make it so that we have to be looking at this information and examining how we are treating women and how we’re looking at the menstrual cycle.

I wouldn’t be surprised if this paper wasn’t one of the many factors that led to the recent change in how PCOS — now PMOS — is being looked at. There is an argument to be made that not all women with long and irregular cycles have PCOS formally. But when we look at that phenomenon of long and irregular cycles consistently, it is often a result of what is happening at the metabolic level. It’s often a result of issues with insulin resistance, and those are the metabolic issues that are actually disrupting the cycle.

This further confirms that the menstrual cycle is truly a vital sign. When the cycle is consistently disrupted over long periods of time, this does correlate with an increase of other health risks and health factors.

While the increased risk of type 2 diabetes and heart failure are significant, there are even larger issues that menstrual cycle irregularities can signal. Abnormal cycle frequency carries the strongest risk factor, with a 74% higher risk of type 2 diabetes and a 43% higher risk of stroke.

When the researchers looked at a second cohort of women whose cycles were either too short or too long, the numbers became even more striking. Women with abnormal cycle frequency were 74% more likely to develop type 2 diabetes and 43% more likely to develop cerebrovascular disease.

It’s showing that there’s a difference between cycle irregularity and abnormal cycle frequency. In the literature, irregular cycles are typically defined as cycles that vary in length by about eight days from cycle to cycle. What’s interesting is that the researchers created a second category where instead of looking for cycle irregularity, they were looking for women whose cycles were just very, very long or very, very short.

They found that when they looked at women with extremely long cycles, there was an even more pronounced risk of these metabolic issues. There is a difference between cycle irregularity that might be a result of a variety of different factors versus women who are consistently having 45-day or 50-day cycles. Those women are far more likely to have a positive diagnosis for something like PCOS or to otherwise have some sort of health risk factor disruption causing it.

There’s no situation where it’s normal for a woman to have consistent 50-day cycles. When we understand how our bodies work and how the menstrual cycle fits into this picture, there’s no scenario where it’s just normal for women to consistently have cycles falling outside of the established parameters.

When the researchers zoned in and looked at the differences between women who had short cycles versus long cycles, it was interesting. Women who had short cycles had a higher risk factor for cerebrovascular disease, hypertension, and type 2 diabetes. Whereas for women who had long cycles specifically, there was an increased risk of type 2 diabetes.

The researchers didn’t specifically define short and long cycles within the context of the study. But generally speaking, normal cycles are typically defined in the literature as somewhere between 21 and 35 days. Short cycles are likely shorter than 21 days or even shorter than 24 days. Long cycles are typically defined as over 35 days.

The researchers demonstrated that different cycle problems predict different cardiovascular outcomes. It’s not just a general blanket statement that irregular cycles mean a higher risk. When they looked at different types of cycle dysfunction — whether short cycles, long cycles, or other permutations — they did find particular increases in health risks based on what they were seeing.

This provides further support to the idea that the menstrual cycle is a vital sign. In this study, they’re looking at menstrual cycle length and frequency. This study isn’t looking at other factors such as painful menstruation, short luteal phase, abnormal cervical mucus patterns, or things like that. But when you look at the menstrual cycle in its entirety, it can provide general information — if the cycle is off, we can have an idea that something’s wrong.

Once we really delve into the research and deeper understanding of the different aspects of the menstrual cycle, it can provide more nuanced information about risk factors for certain conditions based on what we’re seeing. The research in this area is just starting to be established. There is a lot more room for additional research into the connections between the menstrual cycle and health.

Imagine if there were years and millions of dollars devoted to really studying and understanding the female reproductive system and the menstrual cycle. This is just the beginning of where we could be, because this is an area that has significantly been understudied. It shows us that we’re really just at the tip of the iceberg in understanding the connection between the menstrual cycle and overall health.

The last thing I want to mention is that the researchers of this paper are specifically calling for menstrual cycle history to be part of a routine medical evaluation. They’re calling out the fact that our medical system as a whole isn’t necessarily looking at menstrual cycle evaluation as a standard part of their workup for patients, and they’re calling out how little awareness and understanding most physicians have.

It’s not necessarily their fault. There are plenty of physicians who do have an awareness of this, but these are physicians who took additional training outside of what was generally taught. The detailed and nuanced evaluation and understanding of the menstrual cycle and its connection to health is just not a standard part of the medical program. Any doctors who do have this nuanced understanding took additional specialization outside of their initial medical training.

To conclude, this study gives us specific examples of how the menstrual cycle can help us understand what’s happening with overall health. It shows us that the menstrual cycle truly is a vital sign — disruptions in the normal function of the menstrual cycle, changes and alterations to the normal patterns, do indicate a general propensity to some of these risk factors.

When we get into the weeds, specific types of menstrual cycle dysfunction can be indicators of specific medical risk factors. This paper highlights that while there’s plenty of evidence to show these connections and associations, the medical establishment has not formally made menstrual cycle history part of the diagnosis or even the risk factors. Most clinicians aren’t necessarily looking at the cycle in this way.

We know that it can take decades for the newest research to really enter into your average doctor’s office. That is just the unfortunate reality of the situation. But it is encouraging to see that this type of research is being done, that these conversations are being had, and that more and more researchers and medical professionals are starting to ask these questions and look deeper at the menstrual cycle as a sign of health.

I don’t anticipate that the average practitioner has this as part of their workup today. But hopefully within the next five years, ten years, or longer, for our daughters, for our nieces, for the younger generation, we will see a shift and a change in a positive way towards better menstrual cycle health and better overall health for our next generation of women and girls.

I hope that you enjoyed today’s episode. If you want to find out more about this paper, you can find the links in our show notes page. You can head over to fertilityfriday.com and look for this episode and you will find all of the information and links there. I hope you have a wonderful week, weekend, or whenever you’re tuning into the show. And as always, until next time, be well and happy charting.