title: Juvenile fibromyalgia syndrome: Blunted heart rate response and cardiac autonomic dysfunction at diagnosis.
abstract: To assess aerobic capacity and cardiac autonomic modulation in juvenile fibromyalgia syndrome (JFM) patients at diagnosis in response to graded exercise text.
  
  
  
  A multicenter cross-sectional study included 25 JFM patients and 25 healthy controls. Both groups participated only in physical education classes at school. A treadmill graded cardiorespiratory test was performed and the heart-rate (HR) response during exercise was evaluated by the chronotropic reserve (CR). Pain, functional ability, and health-related quality of life (HRQL) were assessed.
  
  
  
  The median current age was similar in JFM and controls (15 vs. 15 years, p = 0.890), as well as body mass index (p = 0.332), female gender (p = 1.000), and Tanner stages (p = 0.822). The medians of HRQL parameters (total score/physical health/psychosocial health) were significantly lower in JFM vs. controls according to patient and parent self-reports (p < 0.001). The median of peak HR [181 (150-198) vs. 197 (181-202)bpm, p < 0.001], chronotropic reserve [84 (53-98) vs. 99 (84-103)%, p < 0.001], and resting to peak [96 (65-181) vs. 127 (61-185)bpm, p = 0.010] were significantly lower in JFM compared to controls. The median of ΔHRR1 [15 (3-39) vs. 35 (9-52)bpm, p < 0.001], ΔHRR2 [37 (20-57) vs. 51 (32-94)bpm, p < 0.001], peak VO2[32.34 (24.24-39.65) vs. 36.4 (28.56-52.71)ml/kg/min, p = 0.005], peak speed [5 (4-6.3) vs. 5.9 (4.0-6.3)mph, p = 0.001], time to exhaustion [11.5 (8.5-14.5) vs. 14 (11-18)min, p < 0.001], and working capacity on power [3.37 (2.04-5.6) vs. 3.89 (2.91-6.55)W/kg, p = 0.006] were significantly lower in JFM compared to controls. The frequency of chronotropic incompetence (≤80%) was significantly higher in JFM vs. controls (p = 0.0006).
  
  
  
  This study identified chronotropic incompetence and delayed HR recovery in JFM patients, indicating autonomic dysfunction. Aerobic exercise training should be considered in all JFM patients and may improve cardiac autonomic impairment, thus reducing cardiovascular risk.
authors.affiliation: Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brazil.
authors.forename: Magda M
authors.initials: MM
authors.lastname: Maia
authors.affiliation: Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brazil; Applied Physiology in Nutrition, Exercise and Genetics Research Group, School of Physical Education and Sport, Universidade de São Paulo, Sao Paulo, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Gualano
authors.affiliation: Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brazil.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Sá-Pinto
authors.affiliation: Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Eneas Carvalho Aguiar, 647-Cerqueira César, Sao Paulo 05403-000, Brazil.
authors.forename: Adriana M E
authors.initials: AM
authors.lastname: Sallum
authors.affiliation: Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brazil.
authors.forename: Rosa M R
authors.initials: RM
authors.lastname: Pereira
authors.affiliation: Pediatric Rheumatology Unit, Universidade Federal de São Paulo, Sao Paulo, Brazil.
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Len
authors.affiliation: Pediatric Rheumatology Unit, Universidade Federal de São Paulo, Sao Paulo, Brazil.
authors.forename: Maria T A
authors.initials: MT
authors.lastname: Terreri
authors.affiliation: Pediatric Rheumatology Unit, Hospital Darcy Vargas, Sao Paulo, Brazil.
authors.forename: Cassia M
authors.initials: CM
authors.lastname: Barbosa
authors.affiliation: Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brazil; Applied Physiology in Nutrition, Exercise and Genetics Research Group, School of Physical Education and Sport, Universidade de São Paulo, Sao Paulo, Brazil.
authors.forename: Hamilton
authors.initials: H
authors.lastname: Roschel
authors.affiliation: Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brazil; Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Eneas Carvalho Aguiar, 647-Cerqueira César, Sao Paulo 05403-000, Brazil. Electronic address: clovisaasilva@gmail.com.
authors.forename: Clovis A
authors.initials: CA
authors.lastname: Silva
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D003430:Cross-Sectional Studies; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D006304:Health Status; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D011788:Quality of Life
keywords: Autonomic dysfunction; Chronotropic reserve; Health-related quality of life; Juvenile fibromyalgia syndrome