title: Responsiveness to exercise training in juvenile dermatomyositis: a twin case study.
abstract: BACKGROUND
  Patients with juvenile dermatomyositis (JDM) often present strong exercise intolerance and muscle weakness. However, the role of exercise training in this disease has not been investigated.
  
  
  OBJECTIVE
  this longitudinal case study reports on the effects of exercise training on a 7-year-old patient with JDM and on her unaffected monozygotic twin sister, who served as a control.
  
  
  METHODS
  Both the patient who was diagnosed with JDM as well as her healthy twin underwent a 16-week exercise training program comprising aerobic and strengthening exercises. We assessed one repetition-maximum (1-RM) leg-press and bench-press strength, balance, mobility and muscle function, blood markers of inflammation and muscle enzymes, aerobic conditioning, and disease activity scores. As a result, the healthy child had an overall greater absolute strength, muscle function and aerobic conditioning compared to her JDM twin pair at baseline and after the trial. However, the twins presented comparable relative improvements in 1-RM bench press, 1-RM leg press, VO2peak, and time-to-exhaustion. The healthy child had greater relative increments in low-back strength and handgrip, whereas the child with JDM presented a higher relative increase in ventilatory anaerobic threshold parameters and functional tests. Quality of life, inflammation, muscle damage and disease activity scores remained unchanged.
  
  
  CONCLUSIONS
  this was the first report to describe the training response of a patient with non-active JDM following an exercise training regimen. The child with JDM exhibited improved strength, muscle function and aerobic conditioning without presenting an exacerbation of the disease.
authors.affiliation: Pediatric Rheumatology Unit, Children's Institute, School of Medicine, University of Sao Paulo (Av, Dr, Arnaldo, 455 - Cerqueira César), Sao Paulo 01246-903, Brazil.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Omori
authors.forename: Danilo M L
authors.initials: DM
authors.lastname: Prado
authors.forename: Bruno
authors.initials: B
authors.lastname: Gualano
authors.forename: Adriana M E
authors.initials: AM
authors.lastname: Sallum
authors.forename: Ana L
authors.initials: AL
authors.lastname: Sá-Pinto
authors.forename: Hamilton
authors.initials: H
authors.lastname: Roschel
authors.forename: Maria B
authors.initials: MB
authors.lastname: Perondi
authors.forename: Clovis A A
authors.initials: CA
authors.lastname: Silva
mesh_terms: D016022:Case-Control Studies; D002648:Child; D003882:Dermatomyositis / Q000503:physiopathology* / Q000628:therapy*; D004185:Disability Evaluation; D015444:Exercise / Q000502:physiology; D005081:Exercise Therapy; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D018908:Muscle Weakness / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011788:Quality of Life; D055070:Resistance Training; D016896:Treatment Outcome