Revista de Medicina Desportiva (English) September 2018 - Page 16

Rev. Med. Desp. informa, 2018; 9(5):14–16. Relative Energy Deficiency in Sports (RED-S) Dra. Adriana de Sousa Lages 1,2 , Dr. Alexandre Rebelo-Marques 2,3,4 , Dr. Francisco Carrilho 1 1 Endocrinology Resident; Endocrinology, Diabetes and Metabolism Department, Coimbra Hospital and University Center; 2 Sports and Exercise Physician, Injury Prevention and Performance Unit, Clínica do Dragão, Espregueira-Mendes Sports Centre – FIFA Medical Centre of Excellence; 3 Head of Department; Endocrinology, Diabetes and Metabolism Department, Coimbra Hospital and University Center. Portugal ABSTRACT The Female Athlete Triad was redefined to Relative Energy Deficiency in Sports to emphasize that the syndrome affects not only female but all athletes and it is multi-organ condition which impairs both health and performance status. The signs and symptoms are often subtle, so high level of suspicion is required to establish an early diagnose. A clinical tool (RED-S CAT) was created to categorize athletes in three risk levels tailoring those who sports activities should be restricted. The treatment is based on restoring energy imbalance by improving energy intake, reducing exercise load or a combination of both strategies. KEYWORDS Energy, sport, athlete, endocrinology Introduction The Female Athlete Triad was con- ceptually defined, in 1997, by the American College Of Sports Medi- cine (ACSM), as quite frequent con- dition found on the female athlete, characterized by food disturbance, amenorrhea and osteoporosis. 1 In 2007, ACSM redefined this concept in order to include three interrelated components: energy availability (EA), associated or not with the pres- ence of food disturbance, menstrual disfunction and bone health. 2 Within this line, the concept of EA was introduced as the energy available for physiological functions, after the subtraction of the energy spent in physical training, from the total energy obtained through food intake. It is desirable a balance between ingestion and energy expenditure, in order to optimize the different basal physiological functions, including growth and development (Figure 1). 3,4 The decrease of EA represents the cornerstone of the metabolic consequences associated with Female Athlete Triad (menstrual dysfunction and bone health). In 2014, the International Olympic Committee (IOC) defined a more comprehensive concept of Relative Energy Deficiency in Sports (RED- S) emphasizing both the inclusion of all athletes (not only female), 14 september 2018 www.revdesportiva.pt and the definition as a multi-organ condition, amplifying the dimension of the problem beyond the “triad” perspective. The proposal was to include ten distinct areas (menstrual function, bone, endocrine, metabolic, hematologic, growth and develop- ment, physiological, cardiovascular, gastrointestinal and immunological) and ten consequences regarding the athlete’s performance (less resist- ance, a higher risk of injury, deficient training response, lower capacity of judgment and cog- nition, condition- ing of coordination and concentra- tion, irritability, depression, lower glycogen reserves and lower muscle strength). 5-8 It is emphasized that the psycho- logical component has the particu- larity of causing, precede or be the result of RED-S. 9 The suppres- sive impact over the immuno- logical function is represented by a deficient type 1 immune response, which is supported by the evidence of a higher prevalence of infections, mainly viral intercurrences, during competitions (especially pulmonary and gastrointestinal diseases). 10-13 Traditionally, it is well described the effect of intensive exercise pro- grams, a low percentage of body-fat and low body-weight on the anterior pituitary function, mainly over the gonadal function, which has a direct suppressive action on bone anabolic function. 2,14 An EA lower than 30 Kcal/kg fat-free mass was associated to disruption of the possibility of the luteinizing hormone (LH), to lower levels of insulin, triiodothyronine (T3), growth hormone (GH), insulin- like growth factor (IGF-1) and leptin, as well as to the increased secretion of cortisol and beta-hydroxybu- tyrate, regardless of sports prac- tice. 15,16 On the other hand, a food intake lower or equal to 45Kcal/Kg fat-free mass/day indicates, proxi- mally, a low EA for adolescents and young adults, especially for female athletes. 17-20 The association between a sus- tained reduced caloric intake and menstrual dysfunction can assume different clinical spectra: irregular menstrual periods (oligomenorrhea –interval between two menstrual cycles greater than 37 days but less than 90 days) up to amenorrhea (permanent or transient absence Figura 1 – Consequências para a saúde do Défice Energético Relativo no Des- porto (adaptado de 4 )