Early Growth Patterns Affect CF Children’s Lung Function at Age 12, Study Shows

Children with cystic fibrosis who are able to recover from below-normal growth in their first two years are more likely to achieve normal growth and better lung condition by 12 years of age, a study shows.

The research, “Early life growth patterns persist for 12 years and impact pulmonary outcomes in cystic fibrosis,” was published in the Journal of Cystic Fibrosis.

Scientists have long known there is a link between young CF patients’ ability to respond to nutrition and their lung condition. The clinical trials Responder I, II and III have been exploring the benefits that children with CF attain when they respond well to nutrition.

Responder I defined responders as those whose weight recovered within two years of their CF diagnosis. The study identified factors that made them more likely to be responders.

Responder II looked at whether responders were able to achieve better lung condition at 6 years — the age when doctors can obtain reliable information on children’s pulmonary function. The study showed that responders had better lung function, fewer cough symptoms, and better chest radiograph scores than non-responders.

Researchers didn’t know whether children who achieved early growth recovery could sustain their lung benefits beyond the age of 6, however. So they decided to conducted Responder III.

The goal was to see if responders who were maintaining adequate growth between ages 2 and 6 could continue to do so up to 12 years of age. The team also wanted to know if non-responders’ growth patterns remained the same between 6 and 12 years.

Another goal of the study was to determine growth patterns’ impact on children’s pulmonary condition at the age of 12 years.

Seventy-six children with CF took part in the Wisconsin CF Neonatal Screening Project. Forty-seven were responders.

Among the responders, 35 followed their growth trajectories and maintained their growth improvement between 2 and 6 years. Forty-seven percent of the 35 sustained the improvement up to 12 years, while the growth improvement of 28 percent leveled off at 6 years of age.

A group that included 25 percent of patients was unable to maintain their growth improvement beyond 2 years of age.

Among the non-responders, 76 percent followed their growth trajectories, failing to improve between 2 and 6 years. The remaining 24 percent did improve their growth. None of the patients in these groups were able to maintain their improvement through 12 years of age, however.

“These data demonstrate that growth patterns established early in life tend to persist and determine subsequent growth trajectories,” the researchers wrote.

The researchers measured the children’s lung function with a yardstick known as forced expiratory volume in one second, or FEV1, and chest radiograph scores. FEV1 is the amount of air a person can force from their lungs in one second after taking a deep breath.

Children with CF who also had a bowel obstruction had worse scores than the others.

Patients whose growth leveled off at two or six years experienced a decline in FEV1 scores between 10 and 12 years.

“Results from this long-term outcome study provide clear evidence that in infants with CF, early nutritional response” leads to “growth trajectories and increases the likelihood of achieving better growth, better lung function and less severe chest radiographic abnormalities through 12 years of age,” the team wrote.

They called for studies “to identify optimal CF interventions that can maximize the chance for achieving early growth recovery, as catch-up growth after infancy is difficult to attain.”