title: Lung function outcome at school age in very low birth weight children.
abstract: OBJECTIVE
  The aim of this study was to assess pulmonary function and its predictors in very low birth weight (birth weight ≤1,500 g) children (VLBWc) with or without bronchopulmonary dysplasia (BPD), born at gestational age ≤32 weeks at a single tertiary center during 1996-1999, after the introduction of surfactant therapy.
  
  
  METHODS
  Of the 120 surviving VLBW children, 48 (40%) VLBWc (22 with prior-BPD) at age 8.5 ± 1.0 years and 46 age-matched controls (8.8 ± 1.4 years) born at term, underwent lung function study.
  
  
  RESULTS
  Adjusted values (z-score) of forced vital capacity (z-FVC), forced expiratory volume in 1 sec (z-FEV1), forced expiratory flow 25-75% (z-FEF25-75), carbon monoxide lung diffusion capacity (z-DLCO), and DLCO/alveolar volume (z-DLCO/VA) were significantly lower than controls (mean difference, 95% CI: -1.35, -1.81 to -0.90, P < 0.001; -1.31, -1.73 to -0.90, P < 0.001; -0.87, -1.29 to -0.46, P < 0.001; -0.98, -1.72 to -0.23, P < 0.001; -0.70, -1.22 to -0.18, P < 0.05; respectively). Residual volume (z-RV) and RV/total lung capacity (RV/TLC) ratio (%) were significantly higher in VLBWc than controls (mean difference, 95% CI: 1.06, 0.44 to 1.68, P < 0.001; 9.54%, 5.73 to 13.3%, P < 0.001; respectively). No differences were found in lung function between VLBWc (no-BPD vs. BPD) with the exception of a significant higher RV/TLC ratio in the BPD-subgroup (mean difference, 95% CI: 7.0%, 0.4 to 13%, P = 0.03). Lung function abnormalities were found in 30 (63%) VLBWc with evidence of airway obstruction and diffusing capacity impairment. A weak relationship was observed between gestational age with z-FVC (r = 0.30, P = 0.04), birth weight with z-FEV1 (r = 0.30, P = 0.04) and RV/TLC ratio (r = -0.49, P = 0.001). The duration of oxygen treatment correlated negatively with the z-DLCO/Va (r = -0.5, P = 0.02). No differences were found in FeNO levels between VLBWc and controls.
  
  
  CONCLUSIONS
  VLBWc at school age showed lung function abnormalities characterized by airway obstruction, hyperinflation, and diffusion impairment. Neonatal lung damage together with preterm birth may play a role in worsening the functional respiratory outcome.
authors.affiliation: Department of Pediatrics, University of Bologna, S. Orsola-Malpighi Hospital Bologna, Italy. salvatore_cazzato@aosp.bo.it
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cazzato
authors.forename: Livia
authors.initials: L
authors.lastname: Ridolfi
authors.forename: Filippo
authors.initials: F
authors.lastname: Bernardi
authors.forename: Giacomo
authors.initials: G
authors.lastname: Faldella
authors.forename: Luca
authors.initials: L
authors.lastname: Bertelli
mesh_terms: D001997:Bronchopulmonary Dysplasia / Q000503:physiopathology*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D019102:Infant, Very Low Birth Weight; D008168:Lung / Q000503:physiopathology*; D008297:Male; D011379:Prognosis; D013147:Spirometry; D013997:Time Factors; D014797:Vital Capacity / Q000502:physiology*
keywords: bronchopulmonary dysplasia; chronic lung disease; lung function; prematurity