VANCOUVER, B.C. -- The adolescent female athlete with amenorrhea who is found to have a low bone density should be treated first with improved diet and vitamin intake, before oral contraceptive treatment is considered, Dr. Aurelia Nattiv said at the annual meeting of the American Medical Society for Sports Medicine.
The problem of the young female athlete who develops an eating disorder and has enough of an energy deficit to become amenorrheic, thereby risking her bone, has not been generally recognized long enough for there to be any definitive guidance for physicians.
Physicians need to suspect this problem, especially in track and cross-country runners with amenorrhea and/or a history of stress fracture, said Dr. Nattiv, director of the osteoporosis center at the University of California, Los Angeles, and a team physician for UCLA.
There is a consensus among experts that a bone density assessment should be considered if a young female has had amenorrhea or oligomenorrhea for more than about 6 months, if there is disordered eating and low weight, and/or in those with a history of stress fracture or low-impact fracture.
While the experts used to prescribe hormone treatment with an oral contraceptive immediately when low bone density was found, most now advocate at least trying to have the patient add calories, calcium, and vitamin D to her diet, Dr. Nattiv said.
Experts are shying away from recommending oral contraceptive therapy as the first line of treatment because the research on whether restoring regular menses in this way actually results in an improvement in bone mass in athletes is conflicting, even though oral contraception has been associated with greater bone mass in other healthy, nonathletic females, Dr. Nattiv said.
"We're seeing studies with results all across the board," she added.
One study showed that oral contraceptive use by female athletes appeared to be associated with decreased bone mineral density in the spine after 2 years of use (Med. Sci. Sports Exerc. 33:873-80, 2001). There was a cohort of nonexercising controls in whom there was no decreased density in that group.
Oral contraceptives may not necessarily restore regular menses right away. It can take 6-9 months in some athletes.
But reversing the energy intake imbalance clearly can restore menses, she said.
Dr. Nattiv said she usually gives an athlete about 6-9 months to increase her calorie intake and have a resumption of regular menses, before turning to an oral contraceptive. Bisphosphonate treatment is not recommended for premenopausal women because animal data suggest bisphosphonates may be teratogenic, she noted.
At the beginning of the diet change, the increase in calories need not be very large and it is recommended that the individual increase gradually, in small increments of 200-300 calories a day.
The athlete may also have to reduce her training somewhat, giving up maybe 1 day per week of exercise.
Not all athletes will gain weight, and that may not be necessary. Dr. Nattiv lets the athlete know that even though she may gain weight, she may also have an improvement in her mood and athletic performance because of the increased energy stores.
Calcium intake for a young female athlete should be in the range of 1,200-1,500 mg a day, and a vitamin D supplement (400 IU/day) can be added, though it may not be necessary in a sunny climate unless the athlete wears a lot of sunscreen.
BY TIMOTHY F. KIRN
COPYRIGHT 2004 International Medical News Group
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