title: Left ventricular morphology and function in adolescents: Relations to fitness and fatness.
abstract: BACKGROUND
  Obesity in childhood predisposes individuals to cardiovascular disease and increased risk of premature all-cause mortality. The aim of this study was to determine differences in LV morphology and function in obese and normal-weight adolescents. Furthermore, relationships between LV outcomes, cardiorespiratory fitness (CRF) and adiposity were explored.
  
  
  METHODS
  LV morphology was assessed using magnetic resonance imaging (MRI) in 20 adolescents (11 normal-weight [BMI equivalent to 18kg/m2-25kg/m2] and 9 obese [BMI equivalent to ≥30kg/m2]); 13.3±1.1years, 45% female, Tanner puberty stage 3 [2-4]) using magnetic resonance imaging (MRI). Global longitudinal strain (GLS), strain rate (SR) and traditional echocardiographic indices were used to assess LV function. CRF (peak oxygen consumption), percent body fat (dual-energy x-ray absorptiometry), abdominal adipose tissue (MRI), and blood biochemistry markers were also evaluated.
  
  
  RESULTS
  Adolescents with obesity showed significantly poorer LV function compared to normal-weight adolescents (P<0.05) indicated by higher GLS (+6.29%) and SR in systole (+0.17s-1), and lower SR in early diastole (-0.61s-1), and tissue Doppler velocities (S' -2.7cm/s; e' -2.3cm/s; A' -1.1cm/s). There were no group differences in LV morphology when indexed to fat free mass (P>0.05). Moderate to strong associations between myocardial contractility and relaxation, adiposity, arterial blood pressure and cardiorespiratory fitness were noted (r=0.49-0.71, P<0.05).
  
  
  CONCLUSIONS
  Obesity in adolescence is associated with altered LV systolic and diastolic function. The notable relationship between LV function, CRF and adiposity highlights the potential utility of multidisciplinary lifestyle interventions to treat diminished LV function in this population.
  
  
  BACKGROUND
  NCT01991106.
authors.affiliation: School of Human Movement and Nutrition Sciences, The University of Queensland, St Lucia, Brisbane, QLD, Australia.
authors.forename: Katrin A
authors.initials: KA
authors.lastname: Dias
authors.affiliation: School of Physiotherapy and Exercise Science, Curtin University, Perth, WA, Australia.
authors.forename: Angela L
authors.initials: AL
authors.lastname: Spence
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Centre, Dallas, TX, USA.
authors.forename: Satyam
authors.initials: S
authors.lastname: Sarma
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom Street, Liverpool L3 3AF, UK.
authors.forename: David
authors.initials: D
authors.lastname: Oxborough
authors.affiliation: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Anita S
authors.initials: AS
authors.lastname: Timilsina
authors.affiliation: Children's Nutrition Research Centre, The University of Queensland, Brisbane, QLD, Australia.
authors.forename: Peter S W
authors.initials: PSW
authors.lastname: Davies
authors.affiliation: Heart Care Partners, The Wesley Hospital, Brisbane, QLD, Australia.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cain
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia; Department of Paediatric Endocrinology, Lady Cilento Children's Hospital, Brisbane, QLD, Australia.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Leong
authors.affiliation: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; Helse Midt-Norge RHF, Strandvegen 1, Stjordal, Norway.
authors.forename: Charlotte B
authors.initials: CB
authors.lastname: Ingul
authors.affiliation: School of Human Movement and Nutrition Sciences, The University of Queensland, St Lucia, Brisbane, QLD, Australia. Electronic address: jcoombes@uq.edu.au.
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Coombes
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D009765:Obesity / Q000000981:diagnostic imaging* / Q000503:physiopathology; D010809:Physical Fitness / Q000502:physiology*; D012741:Sexual Maturation / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Adiposity; Cardiorespiratory fitness; Global longitudinal strain; Global longitudinal strain rate; Left ventricular mass; Tissue Doppler velocities