The effects of intermittent hypoxia on human nasal mucosa

Abstract

Purpose: Intermittent hypoxia (IH) is characterized by hypoxia-reoxygenation, reported to be a critical risk factor for obstructive sleep apnea (OSA). This experiment aimed to evaluate the direct effects of IH on the human nasal mucosa. Methods: The direct effects of IH on the human nasal mucosa was evaluated by measuring the ciliary beat frequency (CBF) and expression levels of inflammatory cytokines (granulocyte-macrophage colony-stimulating factor, transforming growth factor-β, interleukin-6, and tumor necrosis factor-α). The normoxia group was exposed to a normoxic condition for 72 h. The IH group was exposed to 288 cycles of IH (1 cycle: hypoxia, 5 min; subsequent normoxia, 10 min) for 72 h. CBF was measured using an automated computer-based video image processing technique. Changes in the expression of cytokines were assessed by real-time reverse transcription-polymerase chain reaction (RT-PCR). Results: The normoxia group revealed a persistent CBF pattern and a physiological range of inflammatory cytokines. However, the IH group showed a cyclic decrease in CBF and increased expression of inflammatory cytokines. Cytotoxicity assay indicated no difference in the survival rates between the two groups. Conclusions: IH results in increased expression of inflammatory cytokines that adversely affects the mucociliary transport in the upper airway and, consequently, may result in airway inflammation.