Description

• Female athlete triad first described in 1992 to include disordered eating, amenorrhea, osteoporosis
• In 2007, American College of Sports Medicine (ACSM) updated definition to the following: components including low energy availability (with or without disordered eating), menstrual dysfunction, LBMD with each component representing an inter-related spectrum ranging from health to dysfunction
• Low energy availability is fundamental to the triad and full recovery not possible without correction of it (1).
• 2014 Female Athlete Triad Coalition (TC) consensus statement largely agreed with ACSM update and included many recommendations (as later briefly outlined in this review) (1).
• 2014 International Olympic Committee’s position statement from 2014 deviated to consider “Relative Energy Deficiency in Sport” (RED-S) (2).
  • Focus on energy deficiency and its broader physiologic effects beyond bone and menstrual health, ranging from growth to cardiovascular
  • Emphasized similar syndrome in males
• Since then, debate has ensued between the classic TC model and RED-S. TC authors assert that RED-S movement is simply “rebranding” 30+ years worth of triad research.
• TC authors have since released papers introducing the concept of the male athlete triad.
• Concept of energy deficiency in men that seem to be related to reproductive and bone abnormalities
  • Men seem to have a higher threshold to meet low energy availability.
  • Male triad needs to be further evaluated.

Epidemiology

Prevalence

• Overall prevalence: 3/3 criteria (EA, menstrual dysfunction, LBMD): 0–16%. 2/3 criteria: 3–27%. 1/3 criteria: 16–60%.
• Disordered eating higher than general population
• Menstrual dysfunction: Prevalence of secondary amenorrhea is as high as 60% in female athletes compared to 2–5% in the general population.
• LBMD: Using the WHO criteria for LBMD, prevalence of osteopenia (T-score between −1 and −2) ranges from 0% to 40% in female athletes, as compared to ~12% in the general population.
• Full triad more prevalent in lean sports (1.5–6.7%), including swimming and cross country, versus non-lean sports (0–2%), including volleyball and softball.

Etiology and Pathophysiology

• Energy availability is defined by energy intake minus exercise energy expenditure.
  • Low energy availability can occur either intentionally or inadvertently. Examples include increasing training or disordered eating (2).
• When there is low energy availability, energy is shunted from reproduction to more critical functions, such as thermoregulation cellular maintenance.
• Specifically, low energy availability leads to suppression of luteinizing hormone (LH) pulse frequency and thus menstrual dysfunction.
  • This process suppresses ovulation and estrogen concentrations, which can lead to decreased bone formation and increased bone resorption, ultimately leading to LBMD.
• Triad elements exist along a bidirectional continuum of severity, ranging from “healthy” to “unhealthy.” Importantly, elements exist as a triad, although, there is unidirectionally implied from one to another.
  • Low energy availability (with or without an eating disorder) can lead to both menstrual dysfunction and LBMD.
• Menstrual dysfunction (via hypoestrogenemia) can lead to LBMD.
• Other effects of low energy availability seem to include endothelial dysfunction and altered lipid profiles.
• RED-S considers low energy availability to lead to broader physiologic effects including metabolic rate, growth and development, immunity, protein synthesis, hematologic, gastrointestinal, cardiovascular, psychological (3).
• TC authors hold that there may be a basis for RED-S but it is insufficiently supported by evidence at the present time.

Risk Factors

• History of menstrual irregularities and amenorrhea; history of stress fractures and recurrent or nonhealing injuries; history of critical comments about eating or weight from parent or coach; history of depression; history of dieting; personality factors including perfectionism and/or obsessiveness, overtraining, and inappropriate coaching behaviors (1).
• Lean physique sports with an aesthetic component (ballet, figure skating, gymnastics, distance running, diving, and swimming) or sports with weight classifications (martial arts and wrestling). Frequent weigh-ins, consequences for weight gain, and win-at-all-cost attitude all increase risk.
• A lack of family or social support; intense training hours; social isolation or entering a new environment (boarding school or college); an athlete with comorbid psychological conditions (anxiety, depression, and/or obsessive-compulsive disorder)
• Age: Japanese study found stress fracture in teenagers with the Triad but no stress fractures in athletes in their 20s.

General Prevention

• Education of athletes (middle school through college), coaches, trainers, parents, and physicians. Young athletes are extremely impressionable and may turn negative comments and unhealthy advice into maladaptive eating and exercising habits.
• General screening during preparticipation exam (PPE) and annual physicals are endorsed by AAP, AAFP, ACSM, AOSSM, and AMSSM.
• Female Athlete Triad Coalition has 11-question screening to use during PPE (1).
• Screen athletes presenting with “red flag” conditions such as fractures, weight changes, fatigue, amenorrhea, bradycardia, orthostatic hypotension, syncope, arrhythmias, electrolyte abnormalities, or depression.
• Screen for other conditions that may accelerate bone loss, including steroid use, tobacco use, alcohol use, and hyperthyroidism.

Commonly Associated Conditions

• Anorexia nervosa, bulimia nervosa, avoidant or restrictive food intake disorder, and other psychological disorders, including low self-esteem, depression, and anxiety (3)
• LBMD predisposes athletes to stress fractures and may not be fully reversible. This may lead to a higher rate of fractures after menopause.