New study on sleep, looking for kids with early puberty

Dr. Natalie Shaw, a Pediatric Endrocrinologist in Boston, is about to start a new research study looking at sleep architecture (i.e., percent of sleeping spent in deep sleep vs. in REM sleep) in children with precocious puberty.  A number of investigators have shown that there is a dramatic decline in slow-wave (deep) sleep that occurs across adolescence and that the decline occurs earlier in girls than in boys (as does puberty), suggesting that sex steroids may be responsible.  To answer this question, Dr. Shaw will enroll kids with CPP in a study which involves two investigations, one at the time of diagnosis, and a second after at least 6 months of treatment for the CPP.  She will then compare their sleep patterns to similar kids who do not have CPP and do a comparison (pre/post treatment).  Dr. Shaw is very interested to see if exposure to sex steroids affect sleep and if so, if the effects are reversible.  If they are not, she would look into what this means for the children's health.

Deep sleep is known to be important in terms of refreshing a child and preparing them for learning the next day.  (For a not-too-technical discussion, click here.)

If you are interested in enrolling your child, or know anyone else who might be interested in doing so, please pass on the information.  Here is the official notice:

The Reproductive Endocrine Unit at the Massachusetts General Hospital seeks healthy girls (4-8 years old) and boys (4-9 years old) who have started puberty (known as precocious puberty), who have not yet begun treatment and who do not have a sleep disorder.  The purpose of the study is to determine the effect of reproductive hormones like estrogen and testosterone on sleep.

This study involves a screening visit (1 hour) and 1-2 overnight stays at the hospital (from approximately 5pm to 9am) for a sleep study and blood sample(s).  The study will take about 6 months to complete. Payment for participation is up to $250.

Call Natalie at 617-726-1895 or email nshaw@partners.org<mailto:nshaw@partners.org> for more information.


Thank you!

Article on Puberty Before Age 10, Today's New York Times

Hi, Everyone.  A big article on signs of puberty at younger ages came out in today's New York Times.  Part of the discussion in it is about what defines "normal puberty".  Some in the medical community feel that earlier breast development without the activation of the brain found in central precocious puberty (CPP) should not be considered abnormal.  In an earlier post, I made my own opinion about that approach clear. 


The possible causes of early development that are discussed in the NYT piece include many that we have already mentioned in this blog, such as: obesity, certain environmental chemicals, and family factors.


I don't think that I am allowed to attach the full text, but I have included excerpts below. The full article can be found on the NYT website here.  

March 30, 2012

Puberty Before Age 10: A New ‘Normal’?

By ELIZABETH WEIL

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So why are so many girls with no medical disorder growing breasts early? Doctors don’t know exactly why, but they have identified several contributing factors.
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... animal studies show that the exposure to some environmental chemicals can cause bodies to mature early. Of particular concern are endocrine-disrupters, like “xeno-estrogens” or estrogen mimics. These compounds behave like steroid hormones and can alter puberty timing.  
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One concern, among parents and researchers, is the effect of simultaneous exposures to many estrogen-mimics, including the compound BPA, which is ubiquitous. Ninety-three percent of Americans have traces of BPA in their bodies. BPA was first made in 1891 and used as a synthetic estrogen in the 1930s. In the 1950s commercial manufacturers started putting BPA in hard plastics. Since then BPA has been found in many common products, including dental sealants and cash-register receipts. More than a million pounds of the substance are released into the environment each year.

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 Adding to the anxiety is the fact that we know so little about how early puberty works. A few researchers, including Robert Lustig, of Benioff Children’s Hospital, are beginning to wonder if many of those girls with early breast growth are in puberty at all. Lustig is a man prone to big, inflammatory ideas. (He believes that sugar is a poison, as he has argued in this magazine.) To make the case that some girls with early breast growth may not be in puberty, he starts with basic science. True puberty starts in the brain, he explains, with the production of gonadotropin-releasing hormone, or GnRH. “There is no puberty without GnRH,” Lustig told me. GnRH is like the ball that rolls down the ramp that knocks over the book that flips the stereo switch. Specifically, GnRH trips the pituitary, which signals the ovaries. The ovaries then produce estrogen, and the estrogen causes the breasts to grow. But as Lustig points out, the estrogen that is causing that growth in young girls may have a different origin. It may come from the girls’ fat tissue (postmenopausal women produce estrogen in their fat tissue) or from an environmental source. “And if that estrogen didn’t start with GnRH, it’s not puberty, end of story,” Lustig says. “Breast development doesn’t automatically mean early puberty. It might, but it doesn’t have to.” Don’t even get him started on the relationship between pubic-hair growth and puberty. “Any paper linking pubic hair with early puberty is garbage. Gar-bage. Pubic hair just means androgens, or male hormones. The first sign of puberty in girls is estrogen. Androgen is not even on the menu.”

Frank Biro, lead author of the August 2010 Pediatrics paper and director of adolescent medicine at Cincinnati Children’s Hospital, began having similar suspicions last spring after he flew to Denmark to give a lecture. Following his talk, Biro looked over the published data on puberty of his colleague Anders Juul. In Juul’s study, some of the girls with early breast development had unexpectedly low levels of estradiol, the predominant form of estrogen in women’s bodies from the onset of puberty through menopause. Biro had seen a pattern like this in his data, suggesting to him that the early breast growth might be coming from nonovarian estrogens. That is to say, the headwaters for the pubertal changes might not be in the girls’ brains. He is now running models on his own data to see if he can determine where the nonovarian estrogens are coming from.

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Elizabeth Weil is a contributing writer for the magazine and the author of a new memoir about marriage, “No Cheating, No Dying.”

Lavender Oil & Tea Tree Oil

I first became interested in the link between lavender and tea tree oil and signs of early puberty after reading an article in the New England Journal of Medicine (NEJM) related to the topic.  

The article I found, Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils, presents case studies of three prepubertal boys who developed enlarged breasts (gynecomastia). The boys' doctor, Dr. Clifford Bloch, discovered that they had all used lotions, creams, shampoos, styling products or soap with lavender or tea tree oil in them.  Once these products were stopped, the enlarged breasts went away.

In the NEJM article, the authors also present methods and results from in vitro studies they conducted, which confirmed "that lavender oil and tea tree oil possess weak estrogenic and anti-androgenic activities that may contribute to an imbalance in estrogen and androgen pathway signaling." The in vitro studies suggest that lavender oil and and tea tree oil, may not change the level of hormones in the body, but may interfere with their activity in the body.  The authors also wrote that they observed that the amount of exposure to oils seems to be important, i.e. there may be a threshold, below which there is no reaction, but above which, there is.

This made my head spin as I thought of all the products, which contain these oils. Lavender in particular seems to be in everything for kids, e.g., lotions, soaps, even in pure extract, given its purported soothing effect and pleasing smell. 

Here are some additional points for consideration:

1. I cannot comment on the scientific methods used in the in vitro studies. The findings about the boys, however, are based on 3 case reports.  As I discussed in an earlier post, case reports have the lowest strength of evidence, as they are descriptive (rather than based on statistical analysis) and are based on too few patients to be able to draw any real conclusions.

2. Still, even if the study findings are not conclusive and do not provide strong evidence, it can't hurt to be cautious. The NEJM article authors write:

"Until epidemiologic studies are performed to determine the prevalence of gynecomastia associated with exposure to lavender oil and tea tree oil, we suggest that the medical community should be aware of the possibility of endocrine disruption and should caution patients about repeated exposure to any products containing these oils."

3. The NEJM article was reported based on three boys in one doctor's clinical practice. As far as I know, no larger epidemiological studies have been done for boys, nor have any studies been done to determine whether these oils have similar effects in girls.

4. Even without those studies, however, we know that lavender & tea tree oil probably cannot explain why central precocious puberty (CPP) happens in some girls. The reason I feel confident putting this point so strongly is because central precocious puberty is triggered by the brain and we know that the level of hormones in these girls is affected, which differs from the tea tree oil and lavender oil responses.  (An earlier post, found here, explains how CPP happens.)

Therefore, my own conclusions about lavender and tea tree oils are that it probably cannot hurt to remove products with these from your homes if you have children -- , but I doubt that they will ever be found to be big contributors in the CPP mystery.  Again, what we really need, is a well-designed large-scale study to give us better answers.