title: Pulmonary and cardiac function in asymptomatic obese subjects and changes following a structured weight reduction program: a prospective observational study.
abstract: BACKGROUND
  The prevalence of obesity is rising. Obesity can lead to cardiovascular and ventilatory complications through multiple mechanisms. Cardiac and pulmonary function in asymptomatic subjects and the effect of structured dietary programs on cardiac and pulmonary function is unclear.
  
  
  OBJECTIVE
  To determine lung and cardiac function in asymptomatic obese adults and to evaluate whether weight loss positively affects functional parameters.
  
  
  METHODS
  We prospectively evaluated bodyplethysmographic and echocardiographic data in asymptomatic subjects undergoing a structured one-year weight reduction program.
  
  
  RESULTS
  74 subjects (32 male, 42 female; mean age 42±12 years) with an average BMI 42.5±7.9, body weight 123.7±24.9 kg were enrolled. Body weight correlated negatively with vital capacity (R = -0.42, p<0.001), FEV1 (R = -0.497, p<0.001) and positively with P 0.1 (R = 0.32, p = 0.02) and myocardial mass (R = 0.419, p = 0.002). After 4 months the study subjects had significantly reduced their body weight (-26.0±11.8 kg) and BMI (-8.9±3.8) associated with a significant improvement of lung function (absolute changes: vital capacity +5.5±7.5% pred., p<0.001; FEV1+9.8±8.3% pred., p<0.001, ITGV+16.4±16.0% pred., p<0.001, SR tot -17.4±41.5% pred., p<0.01). Moreover, P0.1/Pimax decreased to 47.7% (p<0.01) indicating a decreased respiratory load. The change of FEV1 correlated significantly with the change of body weight (R = -0.31, p = 0.03). Echocardiography demonstrated reduced myocardial wall thickness (-0.08±0.2 cm, p = 0.02) and improved left ventricular myocardial performance index (-0.16±0.35, p = 0.02). Mitral annular plane systolic excursion (+0.14, p = 0.03) and pulmonary outflow acceleration time (AT +26.65±41.3 ms, p = 0.001) increased.
  
  
  CONCLUSIONS
  Even in asymptomatic individuals obesity is associated with abnormalities in pulmonary and cardiac function and increased myocardial mass. All the abnormalities can be reversed by a weight reduction program.
authors.affiliation: Medical Mission Hospital, Academic Teaching Hospital, Julius Maximilian University of Würzburg, Department of Internal Medicine, Würzburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Held
authors.affiliation: Medical Mission Hospital, Academic Teaching Hospital, Julius Maximilian University of Würzburg, Department of Internal Medicine, Würzburg, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Mittnacht
authors.affiliation: Firestone Institute for Respiratory Health, Department of Medicine, Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Kolb
authors.affiliation: Institute of Mathematics, Julius Maximilian University of Würzburg, Würzburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Karl
authors.affiliation: Medical Mission Hospital, Academic Teaching Hospital, Julius Maximilian University of Würzburg, Department of Internal Medicine, Würzburg, Germany.
authors.forename: Berthold
authors.initials: B
authors.lastname: Jany
mesh_terms: D000328:Adult; D015992:Body Mass Index; D004452:Echocardiography; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D010366:Peak Expiratory Flow Rate / Q000502:physiology*; D010993:Plethysmography, Whole Body; D011446:Prospective Studies; D012129:Respiratory Function Tests; D016277:Ventricular Function, Left / Q000502:physiology*; D014797:Vital Capacity / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology*; D061217:Weight Reduction Programs