“It’s not the number of breaths you take, but the moments that take your breath away.” A nice sentiment, but maybe not the inspirational desk plaque you want if you are one of the millions of people who struggle with asthma. And while it shouldn’t make you gasp in surprise, given that our sex hormones affect our health in a myriad of ways, progestérone has an important role in lung function, especially when it comes to asthma.
What is asthma?
Le American Lung Association (ALA) defines asthma as “a chronic lung disease that makes it more difficult to move air in and out of [the] lungs.” It may involve coughing, wheezing, or shortness of breath as the airways periodically become irritated and swollen and excess mucus is produced. Instead of breathing through a wide, flexible tube, it feels like trying to breathe through a narrow straw.
While the exact cause of asthma is not well understood, the ALA cites various contributors and risk factors such as genetics, allergies, lung damage due to infection, pollution, smoking, and obesity. Asthma is also categorized into subtypes based on a person’s triggers (exercise, allergies, sleep, etc.) and based on whether or not certain inflammation-causing white blood cells are present in the airways. Because hormones play a significant and complex role in l'inflammation, and vice-versa, hormonal changes can improve or worsen asthma.
Women have different experiences with asthma at different life stages
A big clue that sex hormones specifically (like œstrogène et progestérone) have some relationship to asthma is that asthma rates vary based on menstrual status and the menstrual cycle. According to the CDC, 7.3% of boys have asthma, compared to 5.6% of girls, but only 6.2% of adult men have asthma compared to 9.7% of women. In other words, for kids, asthma is more common in boys, but after puberty, women are 50% more likely to have asthma than men. Estrogen is generally considered a pro-inflammatory hormone, and the development of asthma during puberty is generally thought to be a result of rising estrogen levels.
Asthma symptoms can also fluctuate along with a woman’s cycle. As if the normal symptoms of PMS aren’t bad enough, this Étude 2024 investigating progesterone and asthma estimates that up to 40% of women with asthma experience perimenstrual asthma, a worsening of asthma symptoms around their period [1]. Progesterone is often considered an anti-inflammatory hormone, and this Étude 2024 on airway inflammation found that mice treated with progesterone had less lung inflammation, less mucus production, and countered the pro-inflammation effects of neutrophils [2]. The lack of this helpful effect during menstruation may contribute to worse symptoms directly before or during a period. Une autre étude also suggested that increased prostaglandines during menstruation may play a role in this effect, highlighting that the relationship between periods and asthma is likely due to multiple factors [3].
Progesterone is often considered an anti-inflammatory hormone, and this 2024 study on airway inflammation found that mice treated with progesterone had less lung inflammation, less mucus production, and countered the pro-inflammation effects of neutrophils. The lack of this helpful effect during menstruation may contribute to worse symptoms directly before or during a period.
Interestingly, while puberty is associated with developing asthma for the first time, so is menopause. A Étude 2024 that followed postmenopausal women for a ten-year period found that this was especially true for women experiencing menopause later in life (after age 50) and for women who used hormone therapy to treat menopause symptoms. Researchers blamed estrogen, generally considered a pro-inflammatory hormone, on this effect [4]. But again, the relationship between hormones and inflammation is a complex one, and multiple hormones play important roles and can either increase ou decrease inflammation at different times.
Connection between progestin-only contraception and asthma attacks
A Étude 2024 exploring the role of sex hormones on asthma symptoms analyzed the UK’s Clinical Practice Research Datalink (CPRD) to find correlations between contraceptive use and asthma attacks [5]. This dataset contains anonymous health data from over 60 million patients in the United Kingdom. Of these 60 million patients, over 826,000 were women with asthma, and over half of these women had used oral contraceptives at some point. 132,676 women met the criteria for their combination-pill (COP) cohort and 129,151 met their criteria for progestin-only pill (POP) cohort. The study specifically looked at women being prescribed contraceptives for the first time and compared them to women who were not currently using contraception. The study analyzed data from these women for a maximum of two years, but for less time if women no longer met the criteria.
There was not a significant difference between women newly prescribed a combination pill (with both synthetic estrogen and progesterone) and non-users, but there were several differences in the progestatif seul cohort. For women under 35, there was a 39% increased risk of asthma attacks with POP use compared to non-users. In women with lower corticosteroid use (lower corticosteroid use implies that these women generally have well-controlled asthma) there was a 20% increased risk of asthma attacks with POP use. Finally, in women with eosinophilic-asthma (with this type of asthma, there are more inflammation-causing white blood cells in the airways) there was a 24% increased risk of asthma attacks (however, this group was smaller, so the correlation is less certain) [5]. The connection between POP use and increased risks of asthma attacks is troubling, especially since the birth control in question, the mini-pill, is available without a prescription and does not list asthma as a reason to avoid it.
The connection between progestin-only pill use and increased risks of asthma attacks is troubling, especially since the birth control in question, the mini-pill, is available without a prescription and does not list asthma as a reason to avoid it.
The progesterone problem
Recall that in studies exploring the phenomenon of perimenstrual asthma, researchers concluded that too little progesterone was the problem exacerbating asthma. But in the study detailed above that found a correlation between using a progestin-only pill or “mini-pill,” researchers concluded that too beaucoup progesterone caused more asthma attacks. What’s the answer? Does progesterone stop asthma or make it worse? There are two main factors that play into this question.
Is the body responding abnormally to progesterone?
First, with asthma, the lungs are not working the way they are supposed to. Like with allergies, the statement “peanuts cause the throat to close” may be true for some people, but that’s not how the body is supposé to work. This effect happens because something has gone wrong. This Étude 2024 investigating the role of progesterone in asthma found that progesterone increases the allergic response in female mice with asthma, and activates cells and proteins that are supposé to contribute to tissue repair but, when dysregulated, instead cause inflammation [6]. A much older study from 1993 discusses how healthy women have higher levels of a protein called beta2-AR during the luteal phase, but women with asthma do not. This protein is involved in smooth muscle relaxation, which comprend opening the airways [7]. It may be that in women with asthma, the body has an abnormal response to progesterone, which contributes to the development of asthma. Indeed, ce commentaire describes a rare condition called progesterone sensitivity, in which a person has an allergic response to rises in progesterone, and one of the symptoms of this condition is asthma [8].
It may be that in women with asthma, the body has an abnormal response to progesterone, which contributes to the development of asthma.
…or is it just responding normally to progestin?
The second factor is that not all progesterone is created equal. In the study that found an association between the mini-pill and asthma attacks, the mini-pill is providing the body with synthetic progesterone (known as progestin) that can have different effects on the body than “home-made” (i.e., endogenous) progesterone. When synthetic progesterone is abundant in the body, the body’s own progesterone production is impeded, and the benefits that natural progesterone provides are lost.
Le bilan
The different risk of asthma attacks at different times in the menstrual cycle can make managing symptoms feel complicated, but it doesn’t have to be. Learning to chart your cycles and charting asthma symptoms alongside fertility signs can help women create a treatment plan that is specific to them, whether their asthma symptoms respond more to rises in estrogen or to dives in progesterone. And, if asthma symptoms are made worse by a hormone imbalance, charting can be the first step to treating the problem at its root.
Learning to chart your cycles and charting asthma symptoms alongside fertility signs can help women create a treatment plan that is specific to them, whether their asthma symptoms respond more to rises in estrogen or to dives in progesterone.
Our bodies don’t act as many systems operating independently, but as a cohesive whole. While asthma is a respiratory disease, it is also an immune problem, inflammatory condition, and a byproduct of the hormones that rise and fall throughout the different stages of our lives. Continued research can help to map these intricate pathways and mechanisms and bring further clarity into what shapes conditions like asthma and the steps we can take to treat them.
