Abstract
Fractional exhaled nitric oxide (FENO50), a marker of allergic airway inflammation, is used in respiratory research and asthma clinical care; however, its trajectory with increasing age during childhood has not been well characterised. We examined FENO50longitudinally during a period of important somatic growth to describe trajectories across childhood and adolescence in healthy participants and evaluate clinical factors as potential determinants of trajectories.
FENO50was collected at six visits over 8 years in a population-based cohort of 1791 schoolchildren without asthma (median age at entry 8.4). Smooth sex-specific FENO50trajectories were estimated using generalised additive mixed models, with participant-level random effects. We evaluated whether sex-specific trajectories were influenced by race/ethnicity, BMI percentile, allergic rhinitis, or puberty.
Different FENO50patterns were observed by sex in later childhood and several factors were associated with either FENO50level or change in FENO50as participants aged. FENO50-age trajectories were similar by sex until age ∼11.5, after which males had greater FENO50change than females. This divergence in FENO50-age trajectories coincides with puberty. Males with higher starting BMI percentile had attenuated FENO50-age slopes. Among males, FENO50levels were lower in non-Hispanic Whites. Among both sexes, participants with rhinitis had higher FENO50. FENO50levels within individuals tracked over time; however, there was considerable variation in FENO50patterns across participants.
FENO50trajectories from longitudinal data provide evidence of sex differences coinciding with puberty, suggesting potential hormone link. Improved understanding of determinants of FENO50trajectories is needed to realise the potential for using individualised predicted FENO50trajectories.
Footnotes
This manuscript has recently been accepted for publication in theEuropean Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of theERJonline. Please open or download the PDF to view this article.
Conflict of interest: Dr. Garcia has nothing to disclose.
Conflict of interest: Dr. zhang reports grants from NIH, grants from AHRQ, grants from VA, grants from CDC, outside the submitted work.
Conflict of interest: Dr. Rappaport has nothing to disclose.
Conflict of interest: Dr. Berhane reports grants from NIH, during the conduct of the study.
Conflict of interest: Dr. Muchmore reports grants from National Institute of Environmental Health Sciences, USA, during the conduct of the study; In addition, Dr. Muchmore has a patent PCT/US2018/042316 pending.
Conflict of interest: Dr. Silkoff has nothing to disclose.
Conflict of interest: Dr. Molshatzki has nothing to disclose.
Conflict of interest: Dr. Gilliland has nothing to disclose.
Conflict of interest: Dr. Eckel reports grants from NIH, during the conduct of the study.
- ReceivedJune 25, 2019.
- AcceptedMarch 24, 2020.
- Copyright ©ERS 2020