Young women who exercise to the point they no longer have menstrual periods run the risk of developing osteoporosis and cardiovascular problems, according to a study done by Anne Zeni Hoch, D.O., assistant professor of physical medicine and rehabilitation, and orthopedic surgery at the Medical College of Wisconsin.
Dr. Hoch will be presenting her findings at a meeting of the American College of Sports Medicine in Baltimore on June 2.
She examined 10 women athletes, with an average age of 21 years, who ran a minimum of 25 miles per week. The women had not been menstruating for an average of two-and-a-half years. The cause of athletically-induced amenorrhea is multi-factorial. Diet, amount of exercise, stress and genetics all play a role. However, recent research is pointing toward diet as a strong risk factor.
Women who exercise for one hour or more per day should consume approximately 45 calories per one kg (2.2 lbs.) of body weight. For example, a 60 kg (132 lb.) woman should consume 2700 calories per day consisting of 60 percent carbohydrates, 15 percent protein and 25 percent fats.
Especially important for women is adequate calcium intake to help prevent osteoporosis and build strong bones. For women ages 11-24 years, the daily recommendation is 1500 mg of calcium or four to five eight-ounce glasses of milk per day.
In the face of an inadequate diet and other stressors, Dr. Hoch explains, a young woman's reproductive system tends to "shut down." This is manifested by the cessation of menstrual periods.
Without menstrual periods, estrogen levels, which are necessary for bones to absorb calcium, are reduced. Not only do the bones fail to absorb calcium, but the body removes calcium from the bones for other functions, thus weakening the body's skeleton.
"The situation can be permanent," says Dr. Hoch. She asserts there are high school girls in the Milwaukee area with osteoporosis -- a disease typically found in postmenopausal women.
Estrogen is also important for heart function. With chronically low estrogen levels, blood vessels lose their ability to dilate when stressed.
Normally, blood vessels in the arm, legs and heart dilate when exercising. However, this study showed that young women with cessation of menses had lost the ability to dilate by 80 percent compared to women runners with normal periods. This is one of the first signs of premature heart disease.
Dr. Hoch is not certain if the arterial damage is reversible. She will be giving the women in the study estrogen supplements to see if it is.
She emphasizes that athletics are wonderful for women for many reasons. What she also emphasizes is that amenorrhea is an abnormal condition that is all too often ignored by coaches and doctors and the women athletes themselves.
"Women athletes," she says, "can erroneously believe that the loss of their menstrual periods is a good sign meaning their training is adequate."
"It's a female athlete issue that has been overlooked. We need to do a better job of taking care of female athletes," she states.
Dr. Hoch, who sees patients at the Froedtert and Medical College Sports Medicine Clinic, is also evaluating the Froedtert and Medical College of Wisconsin's Women's Triathlon Team for the prevalence of the Female Athlete Triad.
This recently-recognized syndrome has three distinct but interrelated conditions -- disordered eating, amenorrhea and osteoporosis. The team consists of 15 women ranging from the elite, Heather Gollnick (the #1 triathlete in the country in her class (age 30-34) to beginners.
Each team member will come in for a pre-participation (season) history and physical examination. At that time they will be screened for the Female Athlete Triad. If they are found to have any symptoms of "triad" they will be treated immediately by a team of practitioners who specialize in women's health and athletes.
Each athlete will also be educated about what the Female Athlete Triad is and see a dietician to assess their diet. Education will be provided on an individual basis for proper nutrition and health as an athlete. Injury patterns will also be tracked throughout the season.
[Contact: Toranj Marphetia]