Abstract:
Background and objective: Obstructive sleep apnoea
(OSA) and asthma are associated, and nocturnal breathing difficulty that is usually identified as asthma-like
symptoms can be present in both conditions. We investigated how nocturnal asthma-like symptoms (NAS) and
bronchial hyper-reactivity (BHR) contribute to the association between OSA risk and current asthma, which is
currently unknown but a clinically important question.
Methods: We used data from 794 middle-aged participants in a population-based cohort who provided information on OSA risk (defined by a STOP-Bang
questionnaire score of at least 3), current asthma and
NAS, and underwent methacholine bronchial challenge
testing. Using regression models, we examined the association between OSA risk and current asthma-NAS subgroups and investigated any effect modification by BHR.
Results: The participants were aged 50 years (49.8%
male). OSA risk was associated with NAS with or without current asthma (odds ratio (OR): 2.6; 95%
CI = 1.3–5.0; OR: 4.2; 95% CI = 1.1–16.1, respectively),
but not with current asthma in the absence of NAS.
BHR was associated with current asthma with or without NAS (OR: 2.9; 95% CI = 1.4–5.9; OR: 3.4; 95%
CI = 2.0–7.0, respectively) but not with NAS in the
absence of current asthma. The associations between
OSA risk and current asthma were neither modified nor
mediated by BHR.
