MONDAY, June 16 (HealthDay News) -- A method for predicting
which teenage female athletes are at risk to stop menstruating --
an important factor in causing the bones to lose mass -- may have
been found, according to a preliminary study.
Up to 25 percent of female high school athletes develop
amenorrhea, or absence of menstruation, compared with 2 percent to
5 percent in the general population, researchers from Massachusetts
General Hospital in Boston found.
The report was expected to be presented Monday at The Endocrine
Society's annual meeting in San Francisco.
Intense exercise and caloric restriction, which cause an energy
deficit in the body, are thought to cause the menstrual
irregularities in athletes.
Amenorrhea can cause infertility and early onset of low bone
density, which may increase the risk of broken bones.
The researchers measured levels of various hormones in females
aged 12 to 18. In particular, levels of ghrelin were examined.
Ghrelin is a hormone that can cause reduce secretion of hormones
that regulate ovarian and menstrual function. People with anorexia
nervosa, another condition of severe energy deficit, have elevated
ghrelin levels.
The scientists found that ghrelin levels were higher in athletes
who were not menstruating than in those who were having their
periods or were non-athletic females. The athletes with higher
ghrelin levels also had lower levels of the sex hormones estrogen
and testosterone.
"These findings suggest that hormonal disorders may explain why
amenorrhea occurs in some but not all adolescent athletes," the
study's presenter, Dr. Madhusmita Misra, a pediatric
endocrinologist at Massachusetts General Hospital, said in a
prepared statement.
"In addition, ghrelin may be an important link between an energy
deficit state and the hormones that regulate menstrual
function."
More information
The National Institute of Child Health and Human Development has
more about
amenorrhea.
