Sex in association to lung function at school age
Overall, the boys born preterm had in many aspects worse lung function than the boys born at term, which was not seen to the same extent in the girls born preterm compared to girls born at term. Boys born very preterm had more airflow limitation during spirometry, more air trapping, higher airway resistance, more peripheral airway dysfunction, lower diffusion capacity, and more ventilation inhomogeneity than boys born at term (Tables 5, E-tables 7 and 8). In comparison with preterm girls, preterm boys had significantly lower expiratory flows, lower dysanapsis ratio, lower diffusion capacity, and more ventilation inhomogeneity.
In girls born very preterm, expiratory flows, dysanapsis ratio, air trapping, and ventilation inhomogeneity were not significantly different from what was measured in girls born at term. However, both boys and girls born very preterm had significantly more small airway dysfunction, as measured by IOS, than their term-born counterparts (Table 5).”