title: Cardiopulmonary Exercise Testing in Patients with Idiopathic Scoliosis.
abstract: BACKGROUND
  Scoliosis causes impairment of the respiratory and cardiovascular systems. Traditional pulmonary function tests only examine patients under static conditions. The aim of our study was to investigate the correlation between radiographic parameters and dynamic cardiopulmonary capacity in patients with idiopathic scoliosis.
  
  
  METHODS
  Forty patients with idiopathic scoliosis were included in this prospective study from January 2014 to February 2016. The patients underwent full radiographic assessment of deformity, pulmonary function testing, and cardiopulmonary bicycle ergometer testing. The impact of the severity of thoracic curvature and kyphosis on pulmonary function and physical capacity was investigated.
  
  
  RESULTS
  Thirty-three female patients with a mean age of 15.5 years (range, 11 to 35 years) and coronal thoracic curvature of 49.4° (range, 24° to 76°) and 7 male subjects with a mean age of 15.9 years (range, 13 to 18 years) and coronal thoracic curvature of 47.1°(range, 22° to 80°) were included. No correlation was found between coronal thoracic curvature and pulmonary function test results in the female patients. Female patients with a thoracic curve of ≥60° had lower blood oxygen saturation at maximal exercise in the cardiopulmonary exercise test (p = 0.032). Female patients with a thoracic curve of ≥50° had a higher respiratory rate (p = 0.041) and ventilation volume per minute (p = 0.046) and lower breathing reserve at maximal exercise (p = 0.038). Thoracic kyphosis in female patients was positively correlated with pulmonary function, as shown by the forced expiratory volume in 1 second (r = 0.456, p = 0.01), forced vital capacity (r = 0.366, p = 0.043), vital capacity (r = 0.525, p = 0.006), and total lung capacity (r = 0.388, p = 0.031), as well as with tidal volume (r = 0.401, p = 0.025) in cardiopulmonary exercise testing. Female patients who engaged in regular exercise had better peak oxygen intake normalized by body weight (p < 0.001), peak oxygen intake normalized by the predicted value (p = 0.003), maximum heart rate (p = 0.020), and heart rate reserve (p = 0.014).
  
  
  CONCLUSIONS
  Overall exercise tolerance was not correlated with the magnitude of the thoracic curve and kyphosis. Some parameters of ventilatory function and pulmonary gas exchange worsened as thoracic curvature increased or kyphosis decreased. Exercise capacity was better in patients who engaged in regular aerobic exercise, and physical activity is recommended for patients with idiopathic scoliosis.
  
  
  METHODS
  Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Departments of Orthopedics (J.S. and Y.L.) and Respiratory Medicine (J.L. and Y.X.), Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, People's Republic of China shenjianxiong@medmail.com.cn.
authors.forename: Jianxiong
authors.initials: J
authors.lastname: Shen
authors.affiliation: Departments of Orthopedics (J.S. and Y.L.) and Respiratory Medicine (J.L. and Y.X.), Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, People's Republic of China.
authors.forename: Youxi
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Departments of Orthopedics (J.S. and Y.L.) and Respiratory Medicine (J.L. and Y.X.), Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, People's Republic of China.
authors.forename: Jinmei
authors.initials: J
authors.lastname: Luo
authors.affiliation: Departments of Orthopedics (J.S. and Y.L.) and Respiratory Medicine (J.L. and Y.X.), Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D011446:Prospective Studies; D012129:Respiratory Function Tests; D012600:Scoliosis / Q000503:physiopathology*; D055815:Young Adult