Pollen exposure is associated with risk of respiratory symptoms during the first year of life.

BACKGROUND Pollen exposure is associated with respiratory symptoms in children and adults. However, the association of pollen exposure with respiratory symptoms during infancy, a particularly vulnerable period, remains unclear. We examined whether pollen exposure is associated with respiratory symptoms in infants and if maternal atopy, infant's sex or air pollution modify this association. METHODS We investigated 14,874 observations from 401 healthy infants of a prospective birth cohort. The association between pollen exposure and respiratory symptoms, assessed in weekly telephone interviews, was evaluated using generalized additive mixed models (GAMM). Effect modification by maternal atopy, infant's sex and air pollution (NO2 , PM2.5 ) was assessed with interaction terms. RESULTS Per infant 37±2 (mean±SD) respiratory symptom scores were assessed during the analysis period (January through September). Pollen exposure was associated with increased respiratory symptoms during the daytime (RR [95% CI] per 10% pollen/m3 : combined 1.006 [1.002, 1.009]; tree 1.005 [1.002, 1.008]; grass 1.009 [1.000, 1.23]) and nighttime (combined 1.003 [0.999, 1.007]; tree 1.003 [0.999, 1.007]; grass 1.014 [1.004, 1.024]). While there was no effect modification by maternal atopy and infant's sex, a complex crossover interaction between combined pollen and PM2.5 was found (p-Value 0.002). CONCLUSION Even as early as during the first year of life, pollen exposure was associated with an increased risk of respiratory symptoms, independent of maternal atopy and infant's sex. Because infancy is a particularly vulnerable period for lung development, the identified adverse effect of pollen exposure may be relevant for the evolvement of chronic childhood asthma

Variability of Tidal Breathing Parameters in Preterm Infants and Associations with Respiratory Morbidity during Infancy: A Cohort Study

Objective: To test whether low variability of tidal volume (V T ) and capnographic indices are predictive of subsequent respiratory morbidity in preterm infants. Study design: In a birth cohort of 133 preterm infants, lung function was performed at 44 weeks postmenstrual age. Associations between the coefficient of variation (CV) of V T (CV VT ) and of expired CO 2 volume per breath (CV VE,CO2 ) with rehospitalization, wheeze, and inhalation therapy during infancy were assessed using logistic regression. Area under the curve (AUC) analysis was used to assess whether outcome prediction using bronchopulmonary dysplasia (BPD) classification was enhanced by CV VT or CV VE,CO2 . Results: For each IQR decrease in CV VT (range, 4%-35%) and CV VE , CO2 (range, 5%-40%), the OR for rehospitalization increased by 2.25 (95% CI, 1.21-4.20) and 2.31 (95% CI, 1.20-4.45), respectively. The predictive value of BPD for rehospitalization was improved when CV VT or CV VE,CO2 was added to the model, with the AUC increasing from 0.56 to 0.66 in both models. No association was found for the other outcomes. Conclusions: Compared with BPD classification alone, including near-term variability of tidal breathing parameters improves the prediction of rehospitalization in infancy. These findings may inform parent counseling and monitoring strategies in preterm infants

Increased Impact of Air Pollution on Lung Function in Preterm vs. Term Infants: The BILD Study.

Rationale Infants born prematurely have impaired capacity to deal with oxidative stress shortly after birth. Objectives We hypothesize that the relative impact of exposure to air pollution on lung function is higher in preterm than in term infants. Methods In the prospective BILD-birth-cohort of 254 preterm and 517 term infants, we investigated associations of particulate matter (PM10) and nitrogen dioxide with lung function at 44 weeks postconceptional age and exhaled markers of inflammation and oxidative stress response (fraction of exhaled nitric oxide (FeNO)) in an explorative hypothesis-driven study design. Multilevel mixed-effects models were used and adjusted for known confounders. Measurements and Main Results Significant associations of PM10 during the second trimester of pregnancy with lung function and FeNO were found in term and preterm infants. Importantly, we observed stronger positive associations in preterm infants (born 32 - 36 weeks), with an increase of [184.9 (79.1, 290.7) mL/min] minute ventilation per 10 µg/m3 increase in PM10 than in term infants [75.3 (19.7, 130.8) mL/min] (pprematurity × PM10 interaction = 0.04, after multiple comparison adjustment padj = 0.09). Associations of PM10 and FeNO differed between moderate to late preterm [3.4 (-0.1, 6.8) ppb] and term [-0.3 (-1.5, 0.9) ppb] infants, the interaction with prematurity was significant (pprematurity × PM10 interaction = 0.006, padj = 0.036). Conclusion Preterm infants showed significant higher susceptibility even to low-to-moderate prenatal air pollution exposure than term infants, leading to increased impairment of postnatal lung function. FeNO results further elucidate differences in inflammatory/oxidative stress response comparing preterms to terms