Blog of the Society for Menstrual Cycle Research

Early Menopause Caused By Makeup?

November 8th, 2012 by Heather Dillaway

It turns out that phthalates – chemicals found in cosmetics, hairspray, packaged food, household cleaners, and other common plastic items – are causing early menopause. At least according to one new study that is getting a lot of hype in the past week or two. A team of researchers from Washington University in St. Louis, MO, studied phthalate levels in blood and urine for over 5,000 women, and those women with the highest levels of pthalates apparently went into menopause an average of at least two years before others.

This study is definitely making news. British news sources are reporting on this study as much as U.S. news sources. Women’s reactions to online news stories about this study are mixed. Women hearing about this study are quick to comment online, saying either (1) how quickly they’ll be running out to buy more makeup (to launch themselves into menopause) or (2) discontinuing their use of makeup (to ward against the effects of pthalates). What I find interesting is how divided women are about whether early menopause is good. Reactions to reports on this study definitely show attitudinal differences among women in that women do not think uniformly about menopause or about the importance of using cosmetics. Women are not  thinking uniformly about how damaging phthalates are to our bodies either.

Of course, by all news reports of this study, phthalates also cause cancer, diabetes, and even feminization of boys (really?), so even if you think early menopause is a good thing you might want to hold off on consuming more phthalates.

What this study (and people’s belief in the study) also reiterates is the fact that our bodies are affected by what we eat, use, and do, as well as what we come into contact with, where we live, etc. Some of the articles reporting on this study focus in on the natural, healthy choices we can make when picking beauty products, household cleaners, prepared food, and other common household items. Who knew there was vegan makeup, for instance? This is all worth a second thought. Sure, we might all want to be done with menstruation sooner than later but phthalate-induced menopause should probably not be our goal.

Understanding Research: Expert Opinion Isn’t Enough

October 15th, 2012 by Paula Derry

Many of us do our own health research, either because we have a specific question or simply to keep up with the news. If we don’t read the original scientific articles, we rely on experts to provide summaries in newspapers, magazines, or on a variety of websites. It seems as though by choosing sources judiciously we should be able to count on finding information that is accurate. However, relying on authority, whether this authority derives from a writer having scientific or medical training, or the writer being a professional journalist, or some other reason, is not enough.

I thought about this recently when I saw an article on Medscape, a website for health professionals, especially physicians, called “Early menopause doubles CVD risk regardless of race.” A summary of a new journal article, it was highlighted on the Medscape home page for many days. It began: “Women who experience early menopause–before their 46th birthday–are twice as likely to suffer from coronary heart disease and stroke as women who don’t enter menopause prematurely, and this finding is independent of traditional risk factors.”  Johns Hopkins University, where one of the authors is employed, issued a press release entitled “Early Menopause Associated With Increased Risk Of Heart Disease, Stroke” which also begins:  “Women who go into early menopause are twice as likely to suffer from coronary heart disease and stroke, new Johns Hopkins-led research suggests.” Similar articles appeared in Medline+ (a National Institutes of Health and National Library of Medicine website), a Blue Cross Blue Shield healthcare news website, and many print newspapers.

So, what was in the original scientific article? The article was published in Menopause, which, like many journals, does not post its articles free online for non-subscribers. Many academic libraries do not carry this journal. However, if a reader does get the original article, these are some of the details: The women in this research were studied for a number of years. The researchers collected information about many predictors of circulatory problems (smoking, diabetes, etc.). The women were also asked at what age they had reached menopause. If this was when they were younger than 46, they were classified as having an “early menopause” whether menopause was caused by surgery (ovaries removed) or occurred naturally. The researchers looked at whether the women developed heart problems or strokes, and created mathematical models to study which predictors of these problems were important.

Twice the number of women with “early menopause” had heart problems compared with women who reached menopause later. This is what is called “relative risk.” The “absolute risk” numbers were: 3% of the women with early menopause had heart problems compared with 1.4% of those who did not; for stroke, the numbers were 2.6% vs. 1%. This is still a difference, but not as dramatic as a twofold increase. In addition, the way the strength of the association was mathematically computed was to first predict heart problems and stroke with more usual predictors: age, risk factors like diabetes. The difference in risk due to menopause was in the uncertainty left after all these other factors had already been taken into account. Further, we don’t know whether the “early menopause” group had other associated characteristics leading to a health difference—if they were unhealthy in other ways. The authors, for example, state that if a woman had a family history of heart problems, and if this was mathematically taken into account before looking at menopause, then early menopause was no longer a predictor of her having a problem. In accounting for results, the article cannot distinguish between surgical and natural menopause, which differ in many ways.

It is true that, in the media accounts of this research, if a reader reads the entire article, qualifiers do appear embedded in the article in some of the sources. Some do say that the number of women in the study who developed heart problems or strokes was small; that this was a correlation, not a cause-and-effect association; or that when family history of cardiovascular disease was taken into account the relationship disappeared (although in Medscape, the author of the study was quoted as saying that “the pattern was still similar”). A piece of misinformation that reappeared in some of the sources was that the increased risk was similar whether the women had early menopause naturally or because their ovaries had been surgically removed. The research article clearly states that the authors did not have sufficient power (in research this means, basically, enough subjects to get an accurate answer to the question) to determine this.

I was puzzled why so much publicity was given to this study.  In my opinion, it did provide some interesting, suggestive results and contributed information about women from a range of ethnic groups (who have been understudied in the past), but the study’s results were modest and inconclusive.  However, what the article did do was to claim to support the underlying assumption that menopause and heart disease are related, an idea that keeps re-occurring in the professional literature, even stated as though it is a fact, although the evidence for it has been at the very best arguable and weak.  A recent SMCR blog post by Chris Hitchcock analyzed media misreporting of the results of another research project intended to test this relationship. In the study I am discussing, highlighting weak data that seems to suggest a relationship between menopause and ill health, blurring the distinction between natural and surgical menopause, contribute to this meta-message.  Ages 40 to 45 would be considered within the normal age range for menopause by many professionals, but is here defined as creating health risks.  I would hate to think that meta-messages promoting ideas that menopause is unhealthy and causes risk of heart disease contributed to the perceived importance of the article.

Reference

Early menopause predicts future coronary heart disease and stroke: the Multi-Ethnic Study of Atherosclerosis.  Melissa Wellons, MD, NCMP, Pamela Ouyang, MBBS, Pamela J. Schreiner, PhD, David M. Herrington, MD, and Dhananjay Vaidya, PhD, Menopause: The Journal of The North American Menopause Society, 2012.  Vol. 19, pp. 1081-1087

Earlier menopause with ovary-saving hysterectomy

November 22nd, 2011 by Chris Hitchcock

Recently Heather Dillaway blogged about the challenges and frustrations of naming, and this blog continues with that theme, looking at a recent article about increased rates of ”ovarian failure” following ovary-preserving hysterectomy.

Ovary-saving hysterectomy linked to early menopause,” reads the USA Today on-line headline, and the article opens with the statement that:

Younger women who have a hysterectomy that spares the ovaries are almost twice as likely to go through early menopause as women who do not have their uteruses removed, according to a new study. 

It’s an alarming statement, and one likely to alarm an already anxious woman. The study in question was a longitudinal study following 406 women aged 30-47 at the time of their surgery and a control group of 465 similar-aged women who did not have a hysterectomy. The study will be published in the December 2011 issue of the peer-reviewed journal Obstetrics & Gynecology, and the news coverage was drawn from the Duke University press release, entitled “Hysterectomy Increases Risk for Earlier Menopause In Younger Women”.

The first challenge of naming is in the subtle difference between the press release’s earlier menopause, and the USA today article’s early menopause. Early menopause is defined as menopause that occurs before the age of 40; the earlier menopause in the article is a difference of about 2 years — an important difference.

In women who no longer have menstrual flow, how did the authors establish menopausal status, or ”ovarian failure”, as they called it? In women with a uterus, menstrual flow is a convenient landmark, which is roughly aligned with the hormonal changes to decide when menopause (or is it post-menopause?) has begun. We assume that 12 months without menstrual flow likely means that there will be no further flow (although that is not always true), and that it is a good estimate of when ovarian hormonal cycles have stopped. In this article, the authors used an annual blood sample to measure a hormone called FSH (follicular stimulating hormone). FSH is high in menopausal women, and an FSH>40 IU/L was used as a criterion for reaching menopause. However, we have known since 1994 that a high FSH level is not diagnostic of menopause, and, indeed, 6 of the 504 women were excluded because they had a baseline FSH > 40 IU/L, despite having menstruated within the previous three months. Regularly cycling women in their 40′s can have high FSH levels, and later have low FSH levels and ovulatory cycles. In menstruating women, blood samples would also be timed, which is not possible for women who don’t menstruate. It would be interesting to know how the high FSH criterion corresponded to menstrual cycle history in the control group.

Studies like this are hard to do. The authors were careful — they enrolled women prior to surgery and followed control women in the same way. To get 403 women with complete data, they started with over 900 women.  The controls were fairly well matched — similar in age, age at first period, c-section and oral contraceptive history. However, women undergoing surgery were more likely to have had at least one full-term pregnancy (84.5% vs 68.3% in controls), and more likely to have had a previous tubal ligation. In addition, fibroids, endometriosis, ovarian cysts and previous surgery for fibroids were more common in those having a hysterectomy. Both the hysterectomy itself and the history of previous surgery, particularly tubal ligation, may also contribute to a difference between the two groups. Finally, women with hysterectomy were heavier than the control group.

By following the two groups, the authors were able to estimate that hysterectomy accelerated the rate of reaching the FSH threshold by about 2 years. This is consistent with other research, and fits with the finding that hysterectomy and other reproductive surgeries are associated with a lower rate of breast cancer, presumably due to lower estrogen exposure.

Readers should note that statements published in re: Cycling are those of individual authors and do not necessarily reflect the positions of the Society as a whole.