589 - Respiratory symptoms and function in adults born prematurely

Poster Number: 589
Publication Number: 589.2785

Background: Preterm infants who survive the neonatal period are prone to respiratory dysfunction characterized by airflow obstruction up to young adulthood and are at risk for developing chronic obstructive pulmonary disease (COPD) in later adulthood. However, few studies have been conducted on former premature infants around the age of 30 years and have evaluated respiratory-related quality of life (QoL).

Objective: To investigate how perinatal factors affect respiratory symptoms and function in adults around the age of 30 years born in the post-surfactant era.

Design/Methods: A total of 1,002 infants were admitted to our neonatal intensive care unit from January 1989 to December 1994. Of the 186 individuals who could be contacted, 124 responded to the Saint George’s Respiratory Questionnaire (SGRQ) Japanese version 2 completely, of whom 18 were excluded from the analysis because the Questionnaire was signed by their parents. Data on histories such as those of smoking and asthma were also obtained. Fifty-one participants underwent subsequent respiratory function testing using the handheld spirometer.

Results: The median age of participants was 30 years (range 27–33). None had been diagnosed with COPD. The perinatal factors, such as preterm birth, low birth weight, supplemental oxygen and/or positive pressure ventilation at 28 days of age, small for gestational age, and surfactant administration, did not significantly affect respiratory-related QoL assessed using the SGRQ total score. However, a history of smoking significantly increased the total score (p < 0.05; adjusted odds ratio, 3.14 [95% CI, 1.15–8.56]). In contrast, respiratory function testing showed a positive correlation between gestational age and forced expiratory volume in 1 s per forced expiratory volume in 6 s (FEV1/FEV6) (ρ = 0.31, p < 0.05). Low-birth-weight infants had significantly lower FEV1/FEV6 than those who were not (median 0.86 vs. 0.90, p < 0.05). The percentage predicted FEV1 (%FEV1) was low in preterm and low-birth-weight infants; however, the difference was not statistically significant. No significant association was found between other factors and respiratory function.

Conclusion(s): This study suggests that perinatal factors do not have a strong impact on respiratory symptoms at this age, whereas obstructive airflow limitation due to prematurity silently carries over. As even a few years of smoking considerably worsens respiratory symptoms, smoking cessation guidance should be emphasized for adults who have survived preterm birth and low birth weight.