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The decline in estrogen during menopause leads to poor health outcomes, and it acts as an important marker for a woman’s future health, says Dr. Gita Mishra, professor, life course epidemiology and deputy head, School of Public Health, The University of Queensland.
The risk of heart disease, osteoporosis, and other conditions increases post menopause. Menopause doesn’t cause these conditions, but it does offer an opportunity for monitoring and actively managing risk factors for various diseases that impact women later in life. A University of Queensland study led by Dr. Mishra, says women under 40 who experience premature menopause had double the risk of a non-fatal cardiovascular event before the age of 60.
“There might be some genes that affect both the age of menopause and cardiovascular disease. It is the genes that are making both things happen, but we see it as menopause causing cardiovascular disease. It is the third party that we need to constantly be aware of. In epidemiology, this is what we call a common cause factor,” says Dr. Mishra.
We spoke to her about what menopause is, it’s symptoms, and its implications for women’s health. Edited excerpts:
Q: What is menopause?
All women will experience menopause. It is a natural process, a part of aging. Most of us will spend at least one third of our lives in the post-menopausal stage. There are two types of menopause. One is natural menopause that is due to aging where the ovaries stop producing eggs and a woman experiences a permanent cessation of her period. It happens during midlife and it is when a woman’s period stops permanently.
The second type of menopause, called surgical menopause, is when a woman has had both her ovaries removed. It usually happens during the time of hysterectomy. There could be various reasons for the removal of ovaries, like ovarian cancer. When that happens, women instantly fall into the menopausal stage.
Now, menopausal transition is a stage in life, when a woman goes from pre-menopause in her late 30s and early 40s to a stage of perimenopause. During perimenopause, her period’s frequency and blood flow will fluctuate. This is when she will start experiencing some of the symptoms of menopause. Perimenopause can sometimes go on for four years, where you’re still bleeding, but not regularly. The flow is not that heavy and you’re experiencing menopausal symptoms that can really affect the quality of a woman’s life. After that her period stops permanently.
We define the age of menopause as 12 months after a woman’s period stops permanently. Some women even go through this transition for 10-11 years.
Age of menopause & its predictors
Q: We have read that in industrialised economies, the average age of menopause is about 51 years. But in India, it is lower, at about 46 years. Talk to us about the age of menopause and what are its predictors?
There is a study that I’ve been leading that has data on 800,000 women, it is called the InterLACE project. And it has large data sets that we are able to look at and identify different variations in age of menopause and what predicts it. We believe that age of menopause is an important marker for a woman’s future health, her past health and also her current health. There’s huge variation in age of menopause; in India and Latin America it is slightly lower than in some of the high-income countries. Let’s remember that one of the best ways to know what your age of menopause is, is knowing the age of menopause of your mother. A significant proportion of age at menopause is genetics.
One of the best ways to know what your age of menopause is, is knowing the age of menopause of your mother. A significant proportion of age at menopause is genetics.
The other thing, in terms of age of menopause, is that the more children you have the later your age of menopause will be. If you’re a smoker, then your age of menopause can be reduced by at least a year. Smokers tend to have earlier menopause.
In India, it’d be interesting to see what is the relationship between tobacco use and age of menopause. I don’t think I’ve seen a lot of data on that. That’s another thing that could be more relevant to Southeast Asia and places like India, where women chew betel leaf and tobacco. We don’t really know how that affects their age at menopause, but we do know smoking brings on menopause earlier. The other thing that you need to know in terms of predictors of age of menopause is that very underweight women or overweight women tend to have an earlier age of menopause, earlier than the normal.
What does this all mean? It means that 10 years before a woman experiences her menopause, her fertility will start to decline. If you have early menopause, and you’re planning to have a kid, you need to take that into account. Therefore, knowing your mother’s age of menopause is important in terms of planning for kids and so forth. The other thing is that there are two definitions of what we call premature menopause. If you have your menopause before the age of 40, it’s what’s known as premature menopause. And if you have a menopause between the age of 40 to 45, it’s known as early menopause. An important thing to remember here is that the definition of premature and early menopause is all based on data from high-income countries where the average age of menopause is about 50-51 years.
For Indian women, the age of premature menopause and early menopause should be slightly earlier because if the average age is about 46-48 years, the whole distribution shifts. So why is this important? Those with premature menopause and early menopause tend to have poorer health outcomes. Now, why is that? It’s because when we have experienced menopause, the production of the hormone estrogen completely stops, our fat cells can still produce estrogen, but ovaries no longer do.
So, why is estrogen important? Research has shown that estrogen is good for heart health and bone health. So all of a sudden, if you have early menopause or premature menopause, estrogen has stopped and then you tend to get this condition of post menopause earlier on.
My team has actually published some work on what are the predictors of premature menopause. And what we’ve found, at least in this data set, is that women who have an earlier age of menarche, whose period started very early on, and those who are, for some reason infertile, the chances are about five times higher for them to experience premature menopause. It’s something in biology; when I say, for instance, early menopause is associated with cardiovascular disease, I think we have to be careful that there could be a third factor that is affecting the age of menopause and also affecting cardiovascular disease. That’s why I like to think that the age of menopause is a marker of future health and past health. But I’m not saying the age of menopause is the one that’s causing you to have cardiovascular disease, it’s just a marker. So if you’re having it earlier, you may be at risk. In some ways, we’re very fortunate we have things like that as a marker as a crystal ball for future health.
Women who have an earlier age of menarche, whose period started very early on, and those who are, for some reason infertile, the chances are about five times higher for them to experience premature menopause.
Watch full interview with Dr. Mishra here.
Menopause as a marker
Q: That’s a very important distinction that you made for us that menopause doesn’t actually cause cardiovascular disease but it is an important marker. It can be sometimes confusing because we often tend to believe that menopause causes osteoporosis, or it causes cardiovascular or heart disease.
Yes, it is a marker. The decline in estrogen that happens during menopause is driving the poor health outcomes. I think that’s really important to understand. There might be some genes that affect both the age of menopause and cardiovascular disease. So it is the genes that are making both things happen, but we see it as menopause causing cardiovascular disease. It is the third party that we need to constantly be aware of. In epidemiology, this is what we call a common cause factor.
Q: Talk to us about the symptoms of menopause and the common symptoms that women experienced during their menopausal transition. One of your studies talks about the relationship between the age of puberty and obesity with the symptoms of menopause, particularly hot flashes and night sweats. Could you tell us more about that?
At least 50% of women will experience some sort of symptoms during menopausal transition. The symptoms which are known to be associated with menopausal transition are what we call vasomotor symptoms. These are two types of symptoms, one is hot flashes, and the other one is night sweats. Hot flashes are when a woman starts to feel warm slightly from her face to her neck for a few minutes, and then it just disappears, it’s usually accompanied by profuse sweating. She may feel cold after that.
Night sweat is the same thing, but it happens at night. The thing about Vasomotor symptoms is that a lot of if it’s prolonged, a lot of women will start feeling anxious about it, it does bother their sleeping patterns. It changes their mood, it’s important to be able to manage vasomotor symptoms properly. We looked at some of the factors that affect vasomotor symptoms, and what we found is that earlier age of puberty or menarche are associated with vasomotor symptoms, more severe ones. Also, obesity. Women who were overweight or obese tended to experience severe vasomotor symptoms. That’s something that we can do something about, we can’t change the age at menarche, but there are other modifiable factors that we can try and perhaps take into account to alleviate some of the symptoms.
Watch full interview with Dr. Mishra here.
More on symptoms of menopause and managing them coming soon.
Professor Gita Mishra
Professor, Life Course Epidemiology and Deputy Head, School of Public Health, The University of Queensland.
Professor Mishra is internationally recognized for her expertise in epidemiology and women’s health, especially for her work on the links between reproductive characteristics and non-communicable diseases in later life, such as diabetes and cardiovascular disease. In addition to research related to ALSWH, her current work includes leading the InterLACE project, a major international collaborative research programme on reproductive health and chronic disease that combines data from more than 800,000 women in 26 studies in 11 countries.
Ph: +61 7 334 65224
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