早産児における気道および実質機能の差次的軌跡

To evaluate whether preterm birth is associated with impaired airway and parenchymal lung function and whether early physiologic phenotypes change or are sustained during follow-up during infancy.

125 infants born preterm underwent forced expiratory flow at 75% (FEF₇₅), expired forced vital capacity (FVC), lung diffusion (D_L), and alveolar volume (V_A) measured longitudinally following discharge from the neonatal intensive care unit.

The average gestational age (GA) of the cohort was 31 weeks (range: 25-36), 52% were female, and 36% were diagnosed with bronchopulmonary dysplasia (BPD). Length and lung function were evaluated at mean corrected ages of 5.4 and 13.6 months; visit 1 (V1) and visit 2 (V2). Significant increases occurred in body length (11.82 cm), FEF₇₅ (94.3 ml/s), FVC (149 ml), D_L (147 ml/min/mmHg), and V_A (254 ml) (P <0.01 for each parameter). When quantified by z-scores based upon full term infants, Δz-length increased significantly (P<0.01); however, there were significant decreases in Δz-FEF₇₅ and Δz-D_L (p<0.01). Lower FEF₇₅ and D_L at V1 were associated with lower values at V2 but not associated with GA or BPD.

Following preterm birth, absolute values for lung function increased during infancy; however, when expressed as z-scores, values were persistently impaired and became more negative relative to full term infants. Airway and parenchymal function may be established early after preterm birth and may contribute to impaired trajectories or dysanapsis later in life.