Background
Previous studies have shown the relationship between club cell secretory protein (Clara) (CC‐16) and respiratory diseases. However, few studies have explored the associations between urine CC‐16 levels and environmental tobacco smoke (ETS) exposure in children. The objective of this study was to evaluate whether ETS exposure is associated with CC‐16 when stratified by asthma status.
Methods
In our study, CC‐16 was measured on 537 children aged 9–15 from northeast China in 2011–2012 using the Human Clara Cell Protein ELISA kits. Doctor‐diagnosed asthma was defined as having ever been diagnosed with asthma by a physician. The relationship between ETS exposure and urine CC‐16 level was assessed using linear regression.
Results
When stratified by asthma status, a negative association between ETS exposure and urine CC‐16 was observed after adjusting for the effects of the related covariates, with an adjusted β coefficient [P value] = −0.31 [0.006] in the first 2 years of life and with an adjusted β coefficient [P value] = −0.68 [0.004] in the first 2 years of life and current.
Conclusions
Our study shows long‐term exposure to ETS was associated with urinary CC‐16 among children without asthma.