Exercise-induced endocrine pathologies

Abstract

There has been a substantial increase in women practicing sports over the past 30 yr. While exercise provides many health benefits, there appears to be a unique set of risks associated with intense exercise for the female athlete. The female athlete triad encompasses these risks, including amenorrhea, osteoporosis and eating disorders. The incidence of menstrual irregularities including primary and secondary amenorrhea and shortened luteal phases is much higher among women partaking in athletics, specifically in sports requiring low body weight for performance and aesthetics. The hormone pattern seen in these amenorrheic athletes includes a decrease in GnRH pulses from the hypothalamus, which results in decreased pulsatile secretion of LH and FSH and shuts down stimulation of the ovary. The recently discovered hormone leptin may also play a large role as a significant mediator of reproductive function. The prevalence of eating disorders is high among female athletes who practice sports which emphasize leanness. Consequently, the cause of menstrual irregularities is not due to the exercise alone, but to chronic inadequate or restrictive caloric intake that does not compensate for the energy expenditure. The most dangerous risk associated with amenorrhea for the female athlete is the impact on the skeleton. Complications associated with amenorrhea include compromised bone density, failure to attain peak bone mass in adolescence and increased risk of stress fractures. The diagnosis of exercise-associated menstrual dysfunctions is one of exclusion. The most effective treatment is to decrease the intensity of the exercise and increase the nutritional intake. Hormone replacement has also been under investigation as a possible treatment.