Poor airway function in early infancy and lung function by age 22 years: a non-selective longitudinal cohort study

Abstract

Background: Together with smoking, the lung function attained in early adulthood is one of the strongest predictors of chronic obstructive pulmonary disease. We aimed to investigate whether lung function in early adulthood is, in turn, affected by airway function measured shortly after birth.

Methods: Non-selected infants were enrolled at birth in the Tucson Children's Respiratory Study between 1980 and 1984. We measured maximal expiratory flows at functional residual capacity (Vmax(FRC)) in 169 of these infants by the chest compression technique at a mean of 2.3 months (SD 1.9). We also obtained measurements of lung function for 123 of these participants at least once at ages 11, 16, and 22 years. Indices were forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and forced expiratory flow between 25% and 75% of FVC (FEF25-75), both before and after treatment with a bronchodilator (180 microg of albuterol).

Findings: Participants who had infant Vmax(FRC) in the lowest quartile also had lower values for the FEV1/FVC ratio (-5.2%, p<0.0001), FEF25-75 (-663 mL/s, p<0.0001), and FEV1 (-233 mL, p=0.001) up to age 22, after adjustment for height, weight, age, and sex, than those in the upper three quartiles combined. The magnitude and significance of this effect did not change after additional adjustment for wheeze, smoking, atopy, or parental asthma.

Interpretation: Poor airway function shortly after birth should be recognised as a risk factor for airflow obstruction in young adults. Prevention of chronic obstructive pulmonary disease might need to start in fetal life.

Figure 1

Predicted FEV₁, FEF_25-75 and FEV₁/FVC ratio mean values for males at ages 11, 16 and 22 years by length-adjusted infant V'maxFRC quartile groups using random effects models. Predicted values were standardized to the mean height and weight for males at ages 11, 16 and 22 years. An interaction term between survey (age 11, 16 and 22) and quartiles for infant V'maxFRC was included in the models. P-values were estimated at each survey from the models.