Chapter 682 Female Athletes

Menstrual Problems and the Risk of Osteopenia

Overtraining in young women can be associated with its effect on reproductive function and bone mineral status especially when combined with calorie restriction (Chapters 26 and 110).

The majority of bone mass is acquired by the end of the 2nd decade (Chapter 698). About 60-70% of adult bone mass is genetically determined, and the remaining is influenced by 3 controllable factors: exercise, calcium intake, and sex steroids, primarily estrogen. Exercise promotes bone mineralization in the majority of young women and is to be encouraged. In girls with eating disorders and those who exercise to the point of excessive weight loss with amenorrhea or oligomenorrhea, exercise can be detrimental to bone mineral acquisition, resulting in reduced bone mineral content, or osteopenia.

Specifically, bone mineralization is negatively affected by amenorrhea (absence of menstruation for ≥3 consecutive months). This may be influenced by abnormal eating patterns, or “disordered eating.” When occurring together, disordered eating, amenorrhea, and osteoporosis form the female athlete triad. At health supervision visits and the preparticipation physical examination, special attention should be given to screening for any features of the triad.

Menstrual abnormalities (including amenorrhea) results from suppression of the spontaneous hypothalamic pulsatile secretion of gonadotropin-releasing hormone. It is believed that the amenorrhea results from reduced energy availability, defined as energy intake minus expenditure. Energy availability below a threshold of 30 kcal/kg/day lean body mass (LBM) is thought to result in menstrual disturbances. Negative energy balance also appears to lower levels of leptin, which affects both nutritional state and the reproductive system. Other causes to be ruled out are pregnancy, pituitary tumors, thyroid abnormalities, polycystic ovary syndrome, anabolic-androgenic steroid use, and other medication side effects.

The low estrogen state of amenorrhea predisposes the female athlete to osteopenia and puts her at risk for stress fractures, especially of the spine and lower extremity. If left unchecked, bone loss is partially irreversible despite resumed menses, estrogen replacement, or calcium supplements. Routine bone mineral density screening is not recommended but can help guide treatment and return to activity in severe cases.

Normal ovulation and menses can be recovered in athletes with amenorrhea. This usually involves decreasing exercise amount and/or increasing caloric intake. However, many athletes are resistant to decrease their training, and other methods, such as hormone supplementation, should be discussed. Nutritional counseling is important to help the athlete develop a plan for increasing calories. Calcium intake should be addressed, with the goal being at least 1,500 mg daily. If amenorrhea is present for ≥6 mo, hormone supplementation is recommended.

Three eating disorders can occur in the context of amenorrhea: anorexia nervosa, manifesting as weight <85% of estimated ideal body weight with evidence of starvation manifesting as bradycardia, hypothermia, and orthostatic hypotension or orthostatic tachycardia; bulimia nervosa, manifesting as reduced or normal weight with wider fluctuations of weight than would be expected based on the reported caloric intake and exercise; and eating disorder not otherwise specified, with some of the features of either anorexia or bulimia nervosa, yet not meeting all criteria from the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, for diagnosis of either (Chapter 26). The third type of eating disorder is sometimes diagnosed as an atypical eating disorder. Multiple symptoms and methods can occur together, from unhealthy caloric or fat restriction to bingeing and purging. Clues to the problem are weight loss, food restriction, depression, fatigue and worsened athletic performance, and preoccupation with calories and weight. The athlete might avoid events surrounding food consumption or might hide and discard food. Signs and symptoms include fat depletion, muscle wasting, bradycardia worsened from baseline, orthostatic hypotension, constipation, cold intolerance, hypothermia, gastric motility problems, and, in some cases, lanugo. Electrolyte abnormalities can lead to cardiac dysrhythmias. Psychiatric problems (depression, anxiety, suicide risk) are of higher incidence in this population.

For treatment of eating disorders, control of the symptoms is a central theme. The first step is confronting the athlete about the abnormal behavior and unhealthy weight. Generally, exercise is not recommended if the body weight is <85% of estimated ideal body weight, although there are exceptions, especially if the athlete is eumenorrheic. If the athlete is unable to gain weight with nutrition and medical counseling alone, then psychologic consultation is sought.

Most athletes will not initially admit a problem, and many are unaware of the serious physical consequences. A helpful technique in talking to these athletes is to sensitively point out performance issues. Education about decreased strength, endurance, and concentration can be a motivating factor for treatment. Often, the athlete’s family needs to be involved, and the athlete should be encouraged to reveal necessary information to them. Psychology or psychiatry referral is important in the multidisciplinary approach to treatment of disordered eating. It is important for the physician to monitor the athlete’s physical health while the mental health professional is caring for the mental aspects of the eating disorder.