Infant body mass index trajectories and asthma and lung function.

BACKGROUND: The impact of early rapid increase in body mass index (BMI) on asthma risk and subsequent lung function remains contentious, with limited prospective studies during a critical window for lung growth. OBJECTIVE: Our aim was to investigate the associations between BMI trajectories in the first 2 years of life and adolescent asthma and lung function. METHODS: Anthropometric data on 620 infants from the Melbourne Atopy Cohort Study were collected up to 18 times in the first 24 months of the study. BMI trajectories were developed by using group-based trajectory modeling. Associations between these trajectories and spirometry, fractional exhaled nitric oxide level, and current asthma status at 12 and/or 18 years of age were modeled by using multiple linear and logistic regression. RESULTS: A total of 5 BMI trajectories were identified. Compared with those children with the "average" trajectory, the children belonging to the "early-low and catch-up" and "persistently high" BMI trajectories were at higher risk of asthma at the age of 18 years (odds ratios = 2.2 [95% CI = 1.0-4.8] and 2.4 [95% CI = 1.1-5.3], respectively). These trajectories were also associated with a lower ratio of FEV1 to forced vital capacity and a higher fractional exhaled nitric oxide levels at age 18 years. In addition, children belonging to the persistently low trajectory had lower FEV1 (ß = -183.9 mL [95% CI = -340.9 to -26.9]) and forced vital capacity (ß = -207.8 mL [95% CI = -393.6 to -22.0]) values at the age of 18 years. CONCLUSION: In this cohort, the early-low and catch-up and persistently high trajectories were associated with asthma and obstructive lung function pattern in adolescence. Having a persistently low BMI at an early age was associated with a restrictive pattern. Thus, maintenance of normal growth patterns may lead to improved adolescent respiratory health.

Transient childhood wheeze is associated with less atopy in adolescence.

BACKGROUND: The relationships between childhood wheeze phenotypes and subsequent allergic conditions other than asthma, including hay fever, eczema and sensitization, have not been widely reported. We aimed to investigate this relationship up to late adolescence. METHODS: Using five childhood wheeze phenotypes defined from 620 children in a high-atopy risk birth cohort (Melbourne Atopy Cohort Study), we investigated their relationships with sensitization, eczema, hay fever and fractional exhaled nitric oxide (FeNO) at ages 12 and/or 18 years using logistic and linear regression models. RESULTS: 'Early Persistent wheeze' was associated with the increased risk of eczema (odds ratio: 3.69; 95% CI: 1.23, 11.12) and sensitization (4.52; 1.50, 13.64) at 12 years. 'Intermediate Onset wheeze' was associated with the increased risk of eczema at 12 years (2.57; 1.11, 5.97), hay fever at 12 (2.87; 1.44, 5.74) and 18 years (2.19; 1.20, 4.02), sensitization at 12 (2.25; 1.17, 4.34) and 18 years (2.46; 1.18, 5.12), and raised FeNO at 18 years. 'Late Onset wheeze' was associated with the increased risk of hay fever at 12 (5.18; 1.11, 24.20) and 18 years (4.20; 1.03, 17.11) and sensitization at 12 years (3.27; 0.81, 13.27). In contrast, 'Early Transient wheeze' was associated with the reduced risk of eczema (0.44; 0.20, 0.96), hay fever (0.57; 0.33, 0.99) and sensitization (0.59; 0.35, 0.99) at 18 years and a lower FeNO compared with 'Never/Infrequent wheezers'. CONCLUSIONS: Persistent wheeze phenotypes were associated with allergic outcomes up to 18 years with 'Intermediate Onset wheeze' being the most atopic group. In contrast, 'Early Transient wheezers' had less risk of allergic outcomes at 18 years. This protective effect may reassure parents of wheezy infants and young children.