Open AccessCC16 Levels into Adult Life Are Associated with Nitrogen Dioxide Exposure at Birth
Author(s) -
Paloma I. Beamer,
Melissa Furlong,
Nathan Lothrop,
Stefano Guerra,
Dean Billheimer,
Debra A. Stern,
Jing Zhai,
Marilyn Halonen,
Anne L. Wright,
Fernando D. Martínez
Publication year - 2019
Publication title -
american journal of respiratory and critical care medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.272
H-Index - 374
eISSN - 1535-4970
pISSN - 1073-449X
DOI - 10.1164/rccm.201808-1488oc
Subject(s) - interquartile range , confidence interval , medicine , pediatrics
Rationale: Lung function and growth are adversely associated with nitrogen dioxide (NO 2 ) exposure. Lower levels of circulating club cell secretory protein (CC16) in childhood are also associated with subsequent decreased lung function. NO 2 exposure may induce epithelial damage in lungs and alter club cell proliferation and morphology. Objectives: To determine if increased ambient NO 2 levels at participants' home addresses in early life were associated with decreased levels of CC16 from age 6 to 32 years. Methods: Participants were enrolled at birth in the Tucson Children's Respiratory Study and had circulating CC16 measured at least once between age 6 and 32. Linear mixed models were used to determine the association between estimated ambient NO 2 exposure at participants' home address at birth or age 6 with CC16 levels from age 6 to 32. Measurements and Main Results: NO 2 exposures at birth or age 6 were available for 777 children with one or more CC16 measurement. We found a negative association between NO 2 exposure and CC16 levels, with a 4.7% (95% confidence interval, -8.6 to -0.7) decrease in CC16 levels from age 6 to 32 per interquartile range increase in NO 2 exposure (6.0 ppb) at the participants' birth address. We observed modification by race (p interaction = 0.04), with stronger associations among participants with at least one black parent (-29.6% [95% confidence interval, -42.9% to -13.2%] per interquartile range). NO 2 at participant's age 6 address was not significantly associated with CC16 levels (-1.9%; 95% confidence interval, -6.3 to 2.6). Conclusions: Higher exposure to NO 2 at birth is associated with persistently low levels of CC16 from 6 to 32 years.