Very low birth weight kids more prone to respiratory illnesses at adulthood

"Routine lung function testing and ongoing monitoring are imperative in VLBW and/or very preterm survivors, with targeted intervention for those with abnormal lung function," Dr. Brian Darlow of the University of Otago and colleagues note in the journal Pediatrics.

"Very preterm (<32 weeks' gestation) and very low birth weight (<1500g) infants comprise about 2% of all births but with increasing survival from the late 1970s onwards there are now thousands of former VP and VLBW survivors reaching young adulthood throughout high-income countries," Dr. Darlow told Reuters Health by email.

"We know from multiple studies that very preterm birth is associated with increased respiratory morbidity such chest infections in middle childhood as well as with increased lung obstruction and asthma-like symptoms. But there is less information about the consequences in young adulthood, particularly from population-based studies," he noted.

To investigate, the researchers compared results of a range of lung function tests at age 26 to 30 years in 226 VLBW survivors and 100 term controls born in 1986.

"An obstructive spirometry pattern was identified in 35% VLBW subjects vs 14% controls, with the majority showing mild obstruction," the study team reports. Compared with term-born controls, VLBW adults had a significantly higher incidence of airflow obstruction, gas trapping, reduced gas exchange and increased ventilatory inhomogeneity.

Within the VLBW group, those with BPD showed further worsened airflow obstruction compared with those without BPD.

"The findings suggest the pulmonary effects due to VLBW, although mild, persist into adulthood, and BPD is a further insult on small airway function," the researchers note in their paper.

"Since peak lung function is achieved by the mid-twenties a major interest will be the subsequent rate of decline; will it be similar in VLBW adults and controls or perhaps accelerated in the former group," Dr. Darlow commented in his email.

The researchers concluded that Adult VLBW survivors showed a higher incidence of airflow obstruction, gas trapping, reduced gas exchange, and increased ventilatory inhomogeneity versus controls. The findings suggest pulmonary effects due to VLBW persist into adulthood, and BPD is a further insult on small airway function.

Therefore these findings highlight importance of avoiding factors that may accelerate lung-function decline, particularly smoking, in VLBW adults. However, it's "disappointing" that nearly a third of VLBW adults were current smokers, the researchers note in their paper.

Influenza immunization and avoiding secondhand smoke and air pollution is also particularly pertinent for VLBW adults, they say.