title: Dynamics of heart rate variability analysed through nonlinear and linear dynamics is already impaired in young type 1 diabetic subjects.
abstract: BACKGROUND
  Autonomic diabetic neuropathy is one of the most common complications of type 1 diabetes mellitus, and studies using heart rate variability to investigate these individuals have shown inconclusive results regarding autonomic nervous system activation. Aims To investigate the dynamics of heart rate in young subjects with type 1 diabetes mellitus through nonlinear and linear methods of heart rate variability.
  
  
  METHODS
  We evaluated 20 subjects with type 1 diabetes mellitus and 23 healthy control subjects. We obtained the following nonlinear indices from the recurrence plot: recurrence rate (REC), determinism (DET), and Shanon entropy (ES), and we analysed indices in the frequency (LF and HF in ms2 and normalised units - nu - and LF/HF ratio) and time domains (SDNN and RMSSD), through analysis of 1000 R-R intervals, captured by a heart rate monitor.
  
  
  RESULTS
  There were reduced values (p<0.05) for individuals with type 1 diabetes mellitus compared with healthy subjects in the following indices: DET, REC, ES, RMSSD, SDNN, LF (ms2), and HF (ms2). In relation to the recurrence plot, subjects with type 1 diabetes mellitus demonstrated lower recurrence and greater variation in their plot, inter-group and intra-group, respectively.
  
  
  CONCLUSIONS
  Young subjects with type 1 diabetes mellitus have autonomic nervous system behaviour that tends to randomness compared with healthy young subjects. Moreover, this behaviour is related to reduced sympathetic and parasympathetic activity of the autonomic nervous system.
authors.affiliation: 1Faculdade de Ciências e Tecnologia - FCT/UNESPPresidente Prudente,Marília,SP,Brazil.
authors.forename: Naiara M
authors.initials: NM
authors.lastname: Souza
authors.affiliation: 1Faculdade de Ciências e Tecnologia - FCT/UNESPPresidente Prudente,Marília,SP,Brazil.
authors.forename: Thais R
authors.initials: TR
authors.lastname: Giacon
authors.affiliation: 2Universidade do Oeste Paulista - UNOESTE,Presidente Prudente,Marília,SP,Brazil.
authors.forename: Francis L
authors.initials: FL
authors.lastname: Pacagnelli
authors.affiliation: 1Faculdade de Ciências e Tecnologia - FCT/UNESPPresidente Prudente,Marília,SP,Brazil.
authors.forename: Marianne P C R
authors.initials: MP
authors.lastname: Barbosa
authors.affiliation: 3Faculdade de Filosofia e Ciências - FFC/UNESP,Marília,SP,Brazil.
authors.forename: Vitor E
authors.initials: VE
authors.lastname: Valenti
authors.affiliation: 1Faculdade de Ciências e Tecnologia - FCT/UNESPPresidente Prudente,Marília,SP,Brazil.
authors.forename: Luiz C M
authors.initials: LC
authors.lastname: Vanderlei
mesh_terms: D000293:Adolescent; D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure; D001938:Brazil; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D016014:Linear Models; D008297:Male; D017711:Nonlinear Dynamics; D055815:Young Adult
keywords: Diabetes mellitus type 1; autonomic nervous system; heart rate and young adult; nonlinear dynamics