Objective
To determine whether severity of lung disease at age 6 years is associated with changes in nutritional status before age 6 within individual children with cystic fibrosis (CF).
Study Design
Children with CF born between 1994 and 2005 and followed in the CF Foundation Patient Registry from age ≤2 through 7 years were assessed according to changes in annualized weight-for-length (WFL) percentiles between ages 0 and 2 and body mass index (BMI) percentiles between ages 2 and 6. The association between growth trajectories before age 6 and forced expiratory volume in one second (FEV1) % predicted at age 6-7 years was evaluated using multivariable linear regression.
Results
A total of 6,805 subjects met inclusion criteria. Children with annualized WFL-BMI always >50th percentile [N=1,323 (19%)] had the highest adjusted mean [95% Confidence Interval (CI)] FEV1 at 6-7 years [101.8 (100.1, 103.5)]. FEV1 at 6-7 years for children whose WFL-BMI increased >10 percentile points by age 6 years was 98.3 (96.6, 100.0). This was statistically significantly higher than FEV1 for children whose WFL-BMI was stable [94.4 (92.6, 96.2)] or decreased >10 percentile points [92.9 (91.1, 94.8)]. Among children whose WFL-BMI increased >10 percentile points, achieving and maintaining WFL-BMI >50th percentile at younger ages was associated with significantly higher FEV1 at 6-7 years.
Conclusions
Within-patient changes in nutritional status in the first 6 years of life are significantly associated with FEV1 at age 6-7 years, suggesting that interventions that improve nutrition in early life may lead to improvements in later lung function.