title: Systolic and diastolic abnormalities reduce the cardiac response to exercise in adolescents with type 2 diabetes.
abstract: OBJECTIVE
  To better understand the cardiac limitations during exercise in adolescents with type 2 diabetes mellitus (T2DM), we measured left ventricular performance with magnetic resonance imaging (MRI) during exercise in diabetic and nondiabetic adolescents.
  
  
  METHODS
  Thirteen subjects with T2DM, 27 overweight/obese nondiabetic (ObeseND) subjects, and 19 nondiabetic nonobese control subjects were recruited. Cardiac (left ventricular) MRI scans were performed at rest and during submaximal exercise.
  
  
  RESULTS
  Vo2 peak indexed to fat-free mass was reduced in T2DM and ObeseND subjects compared with control subjects (P < 0.0001). Indexed cardiac output increased less during exercise and was 20% lower in T2DM subjects due to reduced stroke volume. This was a consequence of reduced ventricular filling with smaller end-diastolic volume, which decreased further during exercise in T2DM subjects, but not in ObeseND or control subjects. End-systolic volume was also smaller in T2DM subjects. These changes were associated with increased resting and exercise diastolic blood pressure, and total peripheral resistance in T2DM subjects.
  
  
  CONCLUSIONS
  Independently of obesity, T2DM impairs cardiac function during exercise in adolescents.
authors.affiliation: Corresponding author: Paul L. Hofman, p.hofman@auckland.ac.nz.
authors.forename: Teresa E
authors.initials: TE
authors.lastname: Pinto
authors.forename: Silmara
authors.initials: S
authors.lastname: Gusso
authors.forename: Paul L
authors.initials: PL
authors.lastname: Hofman
authors.forename: José G B
authors.initials: JG
authors.lastname: Derraik
authors.forename: Tim S
authors.initials: TS
authors.lastname: Hornung
authors.forename: Wayne S
authors.initials: WS
authors.lastname: Cutfield
authors.forename: J Chris
authors.initials: JC
authors.lastname: Baldi
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D003971:Diastole; D015444:Exercise; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009765:Obesity / Q000503:physiopathology; D013599:Systole; D014655:Vascular Resistance