title: Exercise effects on cardiac size and left ventricular diastolic function: relationships to changes in fitness, fatness, blood pressure and insulin resistance.
abstract: OBJECTIVE
  To determine exercise training effects on cardiac size and left ventricular (LV) diastolic function and relationships of exercise induced changes in physiological and body composition parameters with cardiac parameters.
  
  
  METHODS
  Prospective, randomised controlled trial.
  
  
  METHODS
  Men and women (63.6 (5.7) years, body mass index 29.5 (4.4) kg/m(2)) with untreated hypertension (systolic blood pressure (BP) 130-159 or diastolic BP 85-99 mm Hg).
  
  
  METHODS
  Cardiac size and LV diastolic function, peak oxygen uptake (Vo(2)), muscle strength, general and abdominal fatness, and insulin resistance.
  
  
  METHODS
  6 months of exercise training versus usual care.
  
  
  RESULTS
  When analysed by group at six months, cardiac size and LV diastolic function did not differ between exercisers (n = 51) and controls (n = 53), whereas exercisers had significantly higher peak Vo(2) (28 v 24 ml/kg/min) and strength (383 v 329 kg), and lower fatness (34% v 37%), diastolic BP (73 v 75 mm Hg) and insulin resistance (quantitative insulin sensitivity check index 0.35 v 0.34) versus controls (all p <or= 0.05). By regression analysis, among six month changes, increased peak Vo(2) and reduced abdominal fat were associated with increased cardiac size. Increased peak Vo(2) and reduced abdominal fat, BP and insulin resistance were associated with improved LV diastolic function. r Values ranged from 0.20 to 0.32 (p <or= 0.05).
  
  
  CONCLUSIONS
  When examined by group assignment, exercise had no effect on cardiac size or LV diastolic function. When individual variations in six month changes were examined, participants attaining the greatest increases in fitness and reductions in abdominal fatness, insulin resistance and BP showed a modest trend towards physiological hypertrophy characterised by increased cardiac size and improved LV diastolic function. These results suggest that decreased abdominal fatness may have a role in improving cardiovascular health.
authors.affiliation: The Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA. kstewart@jhmi.edu
authors.forename: K J
authors.initials: KJ
authors.lastname: Stewart
authors.forename: P
authors.initials: P
authors.lastname: Ouyang
authors.forename: A C
authors.initials: AC
authors.lastname: Bacher
authors.forename: S
authors.initials: S
authors.lastname: Lima
authors.forename: E P
authors.initials: EP
authors.lastname: Shapiro
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D001823:Body Composition / Q000502:physiology; D006332:Cardiomegaly / Q000473:pathology / Q000503:physiopathology*; D003971:Diastole; D004452:Echocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D006973:Hypertension / Q000473:pathology / Q000503:physiopathology*; D007333:Insulin Resistance / Q000502:physiology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010809:Physical Fitness; D012044:Regression Analysis; D018487:Ventricular Dysfunction, Left / Q000473:pathology / Q000503:physiopathology*; D049629:Waist-Hip Ratio