title: Bone health, daily physical activity, and exercise tolerance in patients with cystic fibrosis.
abstract: BACKGROUND
  Daily physical activity (PA) may be an excellent tool for the maintenance of bone health in patients with cystic fibrosis (CF). The aim of this study was to analyze the possible association between physical capacity and activity and bone mineral density (BMD) in young adults with CF. A secondary goal was to evaluate vertebral fractures in this population.
  
  
  METHODS
  A cross-sectional study was conducted in 50 patients with CF who were clinically stable and aged > 16 years but not lung transplant recipients. PA was quantified with a portable motion monitor (BodyMedia Fit Armband). Cardiopulmonary exercise and 6-min walk tests were used to assess exercise capacity. BMD was obtained from dual-energy x-ray absorptiometry of the lumbar column, hip, and whole body. To analyze vertebral fractures and deformity, we performed the Genant and Cobb methods.
  
  
  RESULTS
  Daily PA time at low (3-4.8 metabolic equivalent tasks [METs]) and moderate (4.8-7.2 METs) intensity, respectively, was correlated with Z score (BMD) of the lumbar column (r = 0.36, P < .01 and r = 0.59, P < .001), the neck of femur (r = 0.51, P < .001 and r = 0.72, P < .001), and the total hip (r = 0.54, P < .001 and r = 0.74, P < .001). PA, BMI, age, and sex were predictors of BMD. Vertebral fractures correlated with kyphosis (r = 0.42, P = .02), but not with BMD. Patients who were mildly and severely affected differed in vertebral fracture rate and kyphosis prevalence (P = .002 and P = .013, respectively).
  
  
  CONCLUSIONS
  The most active patients with better exercise capacity had higher BMD. Those with more affected pulmonary function had a greater prevalence of vertebral fractures and dorsal kyphosis.
authors.affiliation: Trauma and Orthopaedic Surgery, Virgen del Rocío Hospital, Universidad de Sevilla, Sevilla, Spain. Electronic address: tejerogarciasergio@gmail.com.
authors.forename: Sergio
authors.initials: S
authors.lastname: Tejero García
authors.affiliation: Trauma and Orthopaedic Surgery, Virgen del Rocío Hospital, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Giráldez Sánchez
authors.affiliation: Medical-Surgical Service of Respiratory Diseases, Virgen del Rocío Hospital, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Cejudo
authors.affiliation: Medical-Surgical Service of Respiratory Diseases, Virgen del Rocío Hospital, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Quintana Gallego
authors.affiliation: Cystic Fibrosis Unit, Virgen del Rocío Hospital, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Dapena
authors.affiliation: Nuclear Medicine, Virgen del Rocío Hospital, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: García Jiménez
authors.affiliation: Trauma and Orthopaedic Surgery, Virgen del Rocío Hospital, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Cano Luis
authors.affiliation: Faculty of Medicine, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Gómez de Terreros
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D009043:Motor Activity; D013131:Spine / Q000000981:diagnostic imaging; D055815:Young Adult