Associations between sleep duration, lung function, FeNO and blood eosinophils among current asthmatics (NHANES 2007–12)

Short sleep duration potentially affects the risk of developing asthma and asthmatic exacerbation. Our aim is to determine the associations between sleep duration with asthmatic phenotypes, fraction of exhaled NO (FeNO), blood eosinophils, and lung function among current asthmatics. A total of 558 individuals from the National Health and Nutrition Examination Survey during 2007-2012 were included in this study. Self-reported sleep duration was divided into three groups: short (⩽6 h), healthy (7-8 h) and long (⩾9 h). By using a multivariate generalized additive model with binomial or Poisson regression, the abovementioned associations were evaluated after adjustment for potential confounders. Our study population included 284 short sleepers, 240 healthy sleepers and 34 long sleepers. In multivariate binomial regression analysis, we found that short sleep duration was associated with increased risk of asthma with central obesity (adjusted OR = 0.58, 95%CI: 0.33-0.99, P = 0.047) compared with healthy sleep duration. Multivariate Poisson regression analyses revealed a significant increase in FeNO (adjusted OR = 1.19, 95%CI: 1.14-1.26, P < 0.01) and reduction of blood eosinophil percentage (adjusted OR = 0.86, 95%CI: 0.77-0.96, P < 0.01) in the healthy sleep duration group compared with the short sleep duration group. The individuals with healthy and long sleep duration harbored better lung function than those with short sleep duration, with the exception of FEV1/FVC. Our study suggested that short sleepers potentially increase the risk of asthma with central obesity and lung function impairment than healthy sleepers among current asthmatics. We also observed that short sleep duration is associated with a significant reduction of FeNO and increase of blood eosinophil percentage.