Revista de Medicina Desportiva (English) September 2018 | Page 17

of menstrual cycles with failure to
menstruate for 90 days or longer,
which can be classified as primary
or secondary). When we have amen-
orrhea in the context of low EA and
intense exercise practice should be a
diagnosis of exclusion and is associ-
ated to an inhibitory hypothalamic
action over gonadotropin-releasing
hormone neurons (GnRH) and,
consequently, a disruption of the
physiological pituitary LH pulsatility,
hence be designated by hypotha-
lamic or functional amenorrhea. 21
The association between hypotha-
lamic dysfunction, hypoestrogenism
and low levels of leptin on amenor-
rhoeic female athletes was associ-
ated with a 2-4-fold increased risk of
stress fractures and lower bone min-
eral density (BMD), which may not
be retrievable after normalization of
menstrual cycles throughout adult
life. 21-23 Early low-BMD screening
and diagnosis are severely important
since up to 90 percent of peak bone
mass is acquired by age 18. 24
Subsequently, the concept of low
EA was directly related to deficit
bone health independently of the
coexistence of hypoestrogenism.
This highlights the direct and
independent impact of EA on bone
structure regardless of menstrual
dysfunction. 25-27
Especially in sports that have a
weight-class requirement or for
which a low body-weight or lean
body is believed to give a competi-
tive advantage (usually referred as
lean sports – gymnastics, diving, row-
ing, ballet, running, cycling, jockey-
ing, wrestling, and martial arts),
EA is often conditioned, with an
increased likelihood of eating disor-
ders in athletes of both sexes. 7,9,28
Since RED-S signs and symptoms
are often subtle, it is mandatory to
have a high clinical suspicion during
the medical evaluation through a
detailed medical history (including
questioning of eating habits, the
training program, gynecologic his-
tory and previous history of infec-
tions or stress fractures). Physical
examination should include an eval-
uation of the vital signs and of the
anthropometric data. The presence
of bradycardia, orthostatic hypoten-
sion, BMI < 18.5 kg/m 2 on athletes
older than 18 years of age, parotid
hypertrophy or signs of peripheral
HIGH RISK
RED LIGHT
No competion
No trainning
Use of written contract
MODERATE RISK
YELLOW LIGHT
LOW RISK
GREEN LIGHT
May train as long as he/she is following
the treatment plan
Full sport participation
May compete once medically cleared
under supervision
Figura 2 – Estratificação do atleta por categoria de risco de RED-S para decisão de
retorno à competição, adaptado de Aspetar Sports Medicine Journal, 2018; (6):414-419.
tissue hypoperfusion may raise sus-
picion of an inadequate nutritional
status and/or an eating disorder. 9
Additional diagnostic evaluation
tools may be necessary in specific
cases as Bone Densitometry Scan
on female athletes with menstrual
dysfunction, low BMI (< 17,5 kg/
m 2 ) or 10 percent reduction in body
weight over a one-month period,
past history of two stress fractures
and/or presence of an eating dis-
order. 7 It should be noted that on
children, adolescents and premeno-
pausal women, the diagnosis of low
BMD should be based on Z-score (and
not the T-Score). 6 Laboratory evalua-
tion can include ionogram, complete
blood cell count and full evaluation
of integrity of the anterior hypo-
thalamus-pituitary axis, including
the thyroid stimulating hormone
(TSH) and free thyroxine (T4), follicle
stimulating hormone (FSH), LH and
prolactin. 22
Although there is a growing
awareness for the diagnosis and rec-
ognition of the different components
of the syndrome among athletes and
their entourage, continuing training
will be necessary for each member
of the multidisciplinary sports team
to warn about the negative impact
of energy deficit besides gonadal
dysfunction and bone health and,
above all, to including female and
male athletes in this nosological
classification. 29-34 The qualification
of these professionals is essential,
allowing an early diagnosis and
minimizing the negative impact on
health and performance of the ath-
lete of low EA. Using standard tools
for periodic athlete evaluation is the
correct strategy adopted to follow-
up and surveillance. 9
To simplify and standardize the
screening and follow-up of athletes,
the IOC created in 2015 one clinical
evaluation tool (RED-S CAT) to assist
the professionals on the evaluation
of the athlete. The screening may
be included as part of the athlete’s
annual health examination and/
or whenever there is evidence of an
eating disorder (anorexia nervosa,
bulimia, restrictive diet or extreme
weight loss techniques), menstrual
dysfunction (secondary amenorrhea
over than six months or primary
amenorrhea after 16 years of age),
previous history of stress fracture,
significant weight loss (over 5 to
10% reduction in body weight over
one-month period), changes on tar-
get height as predicted by parental
height, the performance deficit or an
obvious mood or behavior distur-
bance. 9
The clinical tool proposed by IOC
categorizes the athletes in three
levels according to the RED-S risk
level (red light – high risk; yellow
light – moderate risk and green light
– low risk) and integrates clinical
and laboratory parameters eas-
ily accessible during the clinical
evaluation and athlete follow-up.
This definition in categories will be
also essential for stop-training and
return to play decision by the medical
team. Thus, the endpoints identi-
fied, as high-risk category (red light)
should not be cleared to take part in
sport because of the inherent health
risk associated to the practice and
should receive adequate therapy to
restore the EA focusing on treatment
Disponibilidade energética (DE)
Ingestão energética total diária – energia gasta exercício
Massa livre de gordura corporal
Figure 1 – Estimated energy availability calculation formula accor-
ding to Loucks Et Al., 2011.
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