Overview
Definition:
Amenorrhea in athletes refers to the absence of menstruation
Primary amenorrhea is the failure to menstruate by age 15, while secondary amenorrhea is the cessation of menstruation for at least three consecutive cycles after menarche
In athletes, this is often a symptom of the Relative Energy Deficiency in Sport (RED-S) syndrome, a complex interplay of inadequate energy availability, impaired physiological function, and detrimental health consequences, including compromised bone health.
Epidemiology:
The prevalence of amenorrhea in female athletes varies widely by sport, with higher rates reported in endurance sports (e.g., running, cycling), aesthetic sports (e.g., gymnastics, ballet), and sports with weight class categories
Estimates range from 2% to over 50% in some elite athlete populations
RED-S, encompassing amenorrhea, affects a significant proportion of athletes exhibiting these symptoms, leading to potential bone fragility.
Clinical Significance:
Amenorrhea in athletes is a critical indicator of potential RED-S and can have serious long-term health implications, most notably impaired bone health
Chronic low energy availability disrupts the hypothalamic-pituitary-ovarian (HPO) axis, leading to estrogen deficiency, which is crucial for bone remodeling and maintenance
This can result in decreased bone mineral density (BMD), increasing the risk of stress fractures and osteoporosis, impacting an athlete's career and quality of life.
Clinical Presentation
Symptoms:
Primary amenorrhea by age 15
Secondary amenorrhea (cessation of menses for >= 3 cycles)
Reduced athletic performance
Fatigue and irritability
Disordered eating patterns or concerns about body weight
Increased susceptibility to illness and infections
Poor wound healing
Cold intolerance
Lower back pain or leg pain suggestive of stress fractures.
Signs:
Low body mass index (BMI)
Signs of disordered eating (e.g., body dissatisfaction, restrictive eating)
Low blood pressure
Bradycardia
Palpable stress fractures
Signs of estrogen deficiency like vaginal dryness.
Diagnostic Criteria:
The diagnosis of secondary amenorrhea in athletes relies on a thorough history and physical examination, excluding other causes
The presence of amenorrhea in an athlete is a strong indicator for considering RED-S
For bone health assessment, DEXA scan is crucial
Criteria for osteoporosis typically involve a T-score of -2.5 or lower, while osteopenia is characterized by a T-score between -1 and -2.5.
Diagnostic Approach
History Taking:
Detailed menstrual history including age of menarche, cycle regularity, and duration
Training volume, intensity, and diet
History of disordered eating, body image concerns, or weight loss
Past medical history, including bone fractures
Family history of osteoporosis or hormonal disorders
Current medications and supplements
Red flags: rapid weight loss, extreme exercise regimens, low energy availability.
Physical Examination:
Anthropometric measurements (height, weight, BMI)
Assessment for signs of disordered eating
Palpation for tenderness over bone suggestive of stress fractures
Evaluation of pubertal development
Cardiovascular assessment
Dermatological assessment.
Investigations:
Hormonal assays: Follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, prolactin, thyroid-stimulating hormone (TSH), and testosterone (in females) to evaluate HPO axis function and rule out other endocrine causes
Beta-hCG to rule out pregnancy
Vitamin D and calcium levels
Bone Mineral Density (BMD) using Dual-energy X-ray Absorptiometry (DEXA) scan of the lumbar spine and hip
X-rays may be indicated for suspected stress fractures.
Differential Diagnosis:
Other causes of amenorrhea: Pregnancy
Polycystic ovary syndrome (PCOS)
Hyperprolactinemia
Thyroid dysfunction
Premature ovarian insufficiency (POI)
Uterine abnormalities
Cushing's syndrome
Stress fractures can be confused with other causes of bone pain, including overuse injuries or infections.
Management
Initial Management:
The cornerstone of management is addressing energy availability
This involves increasing caloric intake to match energy expenditure
Nutritional counseling with a registered dietitian specializing in sports nutrition is paramount
Education regarding the risks of RED-S and the importance of adequate energy intake is crucial for the athlete and their support team.
Medical Management:
Hormone replacement therapy (HRT) with estrogen and progesterone may be considered to restore menstrual cycles and improve BMD, especially if energy availability cannot be immediately corrected or if BMD is significantly low
However, HRT does not address the underlying energy deficiency
Calcium and Vitamin D supplementation is essential for bone health
Bisphosphonates might be considered for severe osteoporosis.
Surgical Management:
Surgical management is generally not indicated for amenorrhea or RED-S itself
It may be considered for severe, refractory stress fractures requiring internal fixation, but this is a secondary concern to the underlying RED-S and bone health issues.
Supportive Care:
Multidisciplinary approach involving physicians, sports dietitians, sports psychologists, and coaches
Regular monitoring of menstrual status, energy availability, training load, and BMD
Psychological support to address body image issues and disordered eating behaviors
Gradual return to training once physiological parameters normalize and energy balance is restored.
Complications
Early Complications:
Stress fractures
Increased susceptibility to infections
Poor psychological well-being
Gastrointestinal disturbances.
Late Complications:
Osteoporosis and increased risk of fragility fractures later in life
Infertility
Cardiovascular disease
Anemia
Dental caries
Potential long-term hormonal imbalances.
Prevention Strategies:
Educate athletes and coaches on the risks of RED-S and the importance of adequate energy availability
Monitor training load and nutrition closely
Encourage a balanced diet and regular nutritional assessments
Promote positive body image and healthy attitudes towards weight
Early recognition and intervention are key to preventing long-term complications.
Prognosis
Factors Affecting Prognosis:
The extent and duration of energy deficiency
The severity of hormonal suppression
The degree of bone mineral density loss
Adherence to treatment and lifestyle modifications
Presence of disordered eating behaviors
Age at onset of RED-S.
Outcomes:
With appropriate management, including restoring adequate energy availability and addressing psychological factors, menstrual function can return, and BMD can improve
However, irreversible bone loss may occur with prolonged deficiency
Athletes can often return to sport, but gradual progression of training is necessary.
Follow Up:
Regular follow-up with a sports medicine physician or endocrinologist is essential
This includes monitoring menstrual cycles, BMD (via DEXA scans, typically annually or biennially), hormonal levels, and nutritional status
Ongoing psychological support may be required
Coaches and parents should be involved in the long-term management plan.
Key Points
Exam Focus:
RED-S is a spectrum of impairments resulting from low energy availability, impacting multiple physiological systems including bone health
Amenorrhea is a key indicator of RED-S
Low estrogen levels due to energy deficiency are the primary driver of reduced BMD in female athletes
DEXA scan is the gold standard for assessing bone mineral density in athletes with amenorrhea or suspected RED-S
Management focuses on restoring energy availability and addressing psychological issues.
Clinical Pearls:
Always consider RED-S in any female athlete presenting with amenorrhea or irregular menses, even if they don't appear underweight
Educate athletes that menstrual irregularities are not a badge of honor but a sign of potential harm
A multidisciplinary team approach is crucial for optimal outcomes
Don't just treat the amenorrhea
treat the underlying energy deficiency.
Common Mistakes:
Focusing solely on the amenorrhea without addressing the underlying energy deficiency or disordered eating
Prescribing hormonal therapy without ensuring adequate caloric intake
Dismissing amenorrhea as a normal consequence of intense training
Delaying bone density assessments in athletes with chronic amenorrhea.