Table 1.

Hypothesis of how the severity of asthma increases the prevalence of OSA, including proposed mechanisms via specific pathological pathways.

Proposed Mechanisms	Pathological Pathway
$∆$ Sleep architecture	$\downarrow$ FRC $\downarrow$ Long-term facilitation Respiratory phase interdependence
$\uparrow$ Nasal congestion
$\uparrow$ Type 1 inflammation	$\uparrow$ Bronchoconstriction $\uparrow$ Sputum neutrophils
$\uparrow$ Type 2 inflammation	$\uparrow$ NANC inhibition

OSA: obstructive sleep apnea, FRC: functional residual capacity, NANC: non-adrenergic non-cholinergic neural pathways, $\uparrow$: increased, $\downarrow$: decreased, $∆$: change in.