title: Association of cardiac autonomic modulation with physical and clinical features of young people with type 1 diabetes.
abstract: OBJECTIVE
  The objective of this study was to verify possible associations between heart rate variability indices and physical activity, body composition, and metabolic and cardiovascular parameters in individuals with type 1 diabetes.
  
  
  METHODS
  A total of 39 young patients with type 1 diabetes were included. Body composition, physical activity, cardiovascular parameters, and metabolic parameters were assessed. For the heart rate variability analysis, heart rate was recorded beat-by-beat using a Polar S810i heart rate monitor for 30 minutes, with the volunteers in the supine position; subsequently, the following indices were considered: standard deviation of all normal RR intervals; root-mean square of differences between adjacent normal RR intervals in a time interval; percentage of adjacent RR intervals with a difference of duration >50 ms; high frequency component in milliseconds squared; high frequency component in normalised units; standard deviation of the instantaneous variability beat-to-beat; and standard deviation of the long-term variability. The association between the heart rate variability indices and independent variables was verified through linear regression in unadjusted and adjusted models (considering gender and age). The statistical significance was set at 5% and the confidence interval at 95%.
  
  
  RESULTS
  High values of at-rest heart rate were associated with reduced parasympathetic activity and global heart rate variability, and higher values of waist-to-hip ratio were related to lower parasympathetic activity, independent of age or gender.
  
  
  CONCLUSIONS
  For young patients with type 1 diabetes, increases in at-rest heart rate values are associated with reduced parasympathetic activity and global heart rate variability, whereas higher waist-to-hip ratio values are related to lower parasympathetic activity, both independent of age and gender.
authors.affiliation: 1Faculty of Science and Technology,Universidade Estadual Paulista,Presidente Prudente,São Paulo,Brazil.
authors.forename: Anne K F
authors.initials: AK
authors.lastname: Silva
authors.affiliation: 2Department of Physical Education, Faculty of Science and Technology,Universidade Estadual Paulista,Presidente Prudente,São Paulo,Brazil.
authors.forename: Diego G D
authors.initials: DG
authors.lastname: Christofaro
authors.affiliation: 3Department of Physical Therapy, Faculty of Science and Technology,Universidade Estadual Paulista,Presidente Prudente,São Paulo,Brazil.
authors.forename: Franciele M
authors.initials: FM
authors.lastname: Vanderlei
authors.affiliation: 1Faculty of Science and Technology,Universidade Estadual Paulista,Presidente Prudente,São Paulo,Brazil.
authors.forename: Marianne P C R
authors.initials: MP
authors.lastname: Barbosa
authors.affiliation: 4Cardiorespiratory Research Group,Department of Biological and Medical Sciences, Faculty of Health and Life Sciences,Oxford Brookes University,Oxford,United Kingdom.
authors.forename: David M
authors.initials: DM
authors.lastname: Garner
authors.affiliation: 3Department of Physical Therapy, Faculty of Science and Technology,Universidade Estadual Paulista,Presidente Prudente,São Paulo,Brazil.
authors.forename: Luiz C M
authors.initials: LC
authors.lastname: Vanderlei
mesh_terms: D000293:Adolescent; D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D001823:Body Composition / Q000502:physiology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D011379:Prognosis; D055815:Young Adult
chemical_list: D001786:Blood Glucose
keywords: Diabetes mellitus; autonomic nervous system; heart rate; risk factors; type 1; young adult