The influence of neonatal lung function on rhinovirus-associated wheeze.

RATIONALE

Several studies have shown that the occurrence of wheezing illnesses during the first year of life is associated with lower levels of lung function shortly after birth and before any respiratory illness. It has been suggested that reduced lung function early in life predisposes infants to wheezing during viral respiratory infections, but the association between neonatal lung function and subsequent confirmed viral infections has never been investigated.

OBJECTIVES

To study the influence between neonatal lung function and the occurrence of human rhinovirus (HRV)-associated wheeze.

METHODS

In a prospective birth cohort study, infants were followed from birth through the first year of life with daily questionnaires about respiratory symptoms. Neonatal lung function was performed within the first 2 months of life. Nose and throat swabs were collected during episodes with respiratory symptoms. Polymerase chain reaction was used to detect single HRV infections.

MEASUREMENTS AND MAIN RESULTS

In 176 of the 202 infants (87%) with a single HRV infection, valid lung function measurements were obtained. The risk of wheeze was 1.49 times higher for each SD increase of airway resistance. The adjusted risk (corrected for possible important confounders) for wheeze was 1.77 (95% confidence interval, 1.16-2.69; P = 0.01) times higher for each SD increase of airway resistance. Maternal smoking during pregnancy was independently associated with wheeze (odds ratio 4.42; 95% confidence interval, 1.27-15.5; P = 0.02).

CONCLUSIONS

This study showed that total lung resistance is clearly associated with HRV-associated wheeze. Moreover, HRV-associated wheeze might be the first sign to recognize infants with reduced neonatal lung function.