FRIDAY, April 8 (HealthDay News) -- A lack of leptin contributes
to the absence of menstrual periods in women with extremely low
levels of body fat, but treatment with a synthetic form of the
hormone may restore both the menstrual cycle and fertility, a new
study indicates.
Extremely low levels of body fat can occur in women who are
unusually active, such as runners and dancers, and in those with
eating disorders. These women are prone to the absence of periods
(known to doctors as hypothalamic amenorrhea, or HA), which can
lead to infertility and osteoporosis.
Previous research found that women with HA have chronically low
serum leptin levels. This new study, published online in the
Proceedings of the National Academy of Sciences, is the first to offer definitive proof that a lack of leptin contributes to HA.
The randomized, double-blind study included 20 women, ages 18 to
35, with HA. Many of them were runners. Over 36 weeks, the women
received daily injections of either a synthetic form of leptin
called metreleptin or a placebo, without the participants or the
researchers being aware who was receiving the real or sham
therapy.
Within one month of starting treatment, the women who received
the metreleptin showed significantly increased levels of
leptin.
"Seven of 10 women began to menstruate and four of the seven were found to be ovulating," senior author Dr. Christos Mantzoros, director of the Human Nutrition Unit at Beth Israel Deaconess Medical Center and a professor of medicine at Harvard Medical School, said in a BIDMC news release.
"Compared with women who received the placebo, the women who received the metreleptin therapy were also found to have an improved hormonal profile and exhibited higher levels of biomarkers indicating new bone formation," he added.
The synthetic leptin used in the study, which was funded in part
by the National Institutes of Digestive and Kidney Diseases, was
provided by Amylin Pharmaceuticals, Inc.
More information
The U.S. National Institute of Child Health and Human
Development has more about
amenorrhea.