Life Health Sciences – Science Rules it All

Disordered eating, amenorrhea and osteoporosis make female athlete triad syndrome¹. The syndrome came into notice of health care professionals during 1980’s. Endurance competition for women, like First Women Olympic Marathon held in 1984 and first 10,000 meter race was held in 1988. The fashion for thinness also began in the same era leading to anorexia nervosa. Intense training and disordered eating habits in these athletes are considered to be etiological factor. The syndrome begins with disordered eating then amenorrhea and osteoporosis occurs³. The Incidence of amenorrhea varies in different type of sports and shows training intensity, calories taken and age group involved as associated factor in endurance sports.

Fig1 Beijing Olympics 2008

Half of the runners who run 80 miles per week have amenorrhea. Disordered eating occurs in more than 60% gymnasts. It is result of psychological pressure to maintain body figure and certain body weight. The calorie restriction is common in light weight rovers to maintain low body weight in spite of hard training. Athletes like ballet and gymnasts during late teens are more prone to menstrual irregularities than those in twenties.

Fig.2. Incidence of Amenorrhea

Abnormalities of menstrual functions occur as endurance training is increased, and these increase with increase in intensity of exercise. The luteal phase is decreased; there is less production of progesterone and more anovulatory cycles. The psychological profiling is similar to anorexia nervosa patients. The release of gonadotrophin releasing hormone (GnRH) is slowed down leading to hypothalamus induced suppression of ovaries¹ (hypogonadotrophic hypogonadism) resulting in very low estrogen production. The picture is similar to that in pre-puberty stage.

Fig.3 Hypothalamus-pituitary-ovarian axis

Different factors are responsible for release of hormones including cartisol, insulin-like growth-factor binding protein-1 (IGFBP-1) and leptin. Opioids have inhibitory action on GnRH release. Rise in serum cartisol level in amenorrhic athletes is found as compared to their counterparts without amenorrhea. This occurs due to stress mechanism that causes release of corticotrophin-releasing hormone (CRH). This increases sensitivity of GnRH for opioid inhibition and endorphin release thus causing amenorrhea. There is decrease in bone density due to raised cortisol level.⁴ An other proposed mechanism for amenorrhea is decreased calorie intake by athletes causing energy imbalance in them. Low energy intake but high energy output due to exercise results in weight loss. The athletes usually have body mass index less than 18 and body fat less than 17 percent. They have low BMR, low level of insulin and insulin like growth factor-1 (IGF-1) and try-iodothyronine. It is not still clear how these changes affect GnRH release. The level of IGFDP-1 is found elevated in atheletes with amenorrhea and serum leptin levels are decreased in these athletes but their role in GnRH pulse generator regulation is not clear yet².

The bone density is decreased in athletes with amenorrhea. But the areas of bones involved in high stress activities like femoral necks in runners, spine in rowers, and spinal and femoral neck areas in gymnasts have high bone density. If episodes of amenorrhea are short then bone density is reversible with restoration of normal menstruation. If amenorrhea remains for a longer time the bone density becomes similar to post-menopausal women leading to risk of early osteoporosis. These athletes are prone to stress fractures which are incomplete and usually heal with rest and treatment².

The investigations include identifying the cause of amenorrhea, measuring serum tri-iodo-thyronine and bone mineral density. Assessment of energy and calcium intake is also done. Treatment of female athlete triad syndrome include decreasing amount of exercise, increasing energy intake, psychological intervention, estrogen replacement therapy and supplementing diet with calcium, and vitamin D².

References

1- Otis, C. L., & Goldingay, R. (2000). The athletic woman’s survival guide. Champaign, Illinoi

2- Warrell A D(2005), (Edt). Oxford Textbook of Medicine (Fourth Edition). Oxford University Press, Oxford.

Figures

1- Beijing Olympics China 2008. Picture retrieved from http://www.upi.com

2- Data taken from Wolman RL, Harries MG (1989). Clinical Sports Medicine.

3- Hypothalamus-pituitary-ovarian axis (picture, ch6fb43) retrieved from http://www.ncbi.nlm.nih.gov/bookshelf/picrender.

No related posts.

Related posts brought to you by Yet Another Related Posts Plugin.