title: Difference of catecholamine responses to exercise in men with trisomy 21, with or without chronotropic incompetence.
abstract: OBJECTIVE
  Our purpose was to analyse if catecholamine responses to exercise would be different in Down syndrome (DS) with or without chronotropic incompetence.
  
  
  METHODS
  Twenty five men with DS (mean age 22.2 ± 3.2) and twenty six controls (CONT, mean age 22.5 ± 1.4) participated in the study, and are divided into 3 groups: CONT, DS with chronotropic incompetence (DS+) and DS without chronotropic incompetence (DS-). During two treadmill incremental tests, blood samples were collected for the determination of hormonal and metabolic variables.
  
  
  RESULTS
  Ten out of 25 DS had chronotropic incompetence whereas no CONT. At rest, compared to CONT, despite similar physical activity, DS with chronotropic incompetence had significantly higher subcutaneous fat mass (p<0.001), lower epinephrine concentration (p<0.01), and higher leptin (p<0.01) and insulin concentrations (p<0.05). At peak exercise, all DS had lower heart rate, oxygen uptake and blood lactate concentrations than controls (p<0.001). During a 'Submaximal incremental test', DS with chronotropic incompetence had lower HR and lactate values (p<0.001) compared to CONT and DS without chronotropic incompetence (p<0.01). They also had blunted epinephrine and impaired norepinephrine responses to exercise compared to DS without chronotropic incompetence and CONT (p<0.01 and p<0.05 respectively).
  
  
  CONCLUSIONS
  Our results indicate that catecholamine adaptations to exercise are not adequate in DS+ and are associated with exercise intolerance. Thus, this endocrine profile at rest and during exercise may limit endurance performance of DS.
authors: Univ. Grenoble Alpes, HP2, F-38000 Grenoble, France; INSERM U1042, HP2, F-38000 Grenoble, France.
authors: T
authors: T
authors: Leti
authors: INSERM U1042, HP2, F-38000 Grenoble, France; CHU de Grenoble, Cardiovascular & Thoracic Unit; Sports & Pathologies, F-38000 Grenoble, France.
authors: M
authors: M
authors: Guinot
authors: CHU de Grenoble, Cardiovascular & Thoracic Unit; Sports & Pathologies, F-38000 Grenoble, France.
authors: A
authors: A
authors: Favre-Juvin
authors: Univ. Grenoble Alpes, HP2, F-38000 Grenoble, France; INSERM U1042, HP2, F-38000 Grenoble, France; CHU de Grenoble, Cardiovascular & Thoracic Unit; Sports & Pathologies, F-38000 Grenoble, France. Electronic address: VBricout@chu-grenoble.fr.
authors: V-A
authors: VA
authors: Bricout
mesh_terms: D002318:Cardiovascular Diseases / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D004314:Down Syndrome / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D004837:Epinephrine / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D020738:Leptin / Q000097:blood; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D050151:Subcutaneous Fat / Q000473:pathology; D055815:Young Adult
chemical_list: D007328:Insulin; D020738:Leptin; D019344:Lactic Acid; D009638:Norepinephrine; D004837:Epinephrine
keywords: Chronotropic incompetence; Epinephrine; Heart rate; Norepinephrine; Physical exercise; Trisomy 21