CPAP adherence is often poor in obstructive sleep apnea (OSA) and may be influenced by nasal resistance. CPAP with reduction of expiratory pressure (CPAP) may reduce discomfort in those with high nasal resistance and improve adherence in this subgroup.
To evaluate the association of PAP adherence to nasal resistance and examine if CPAP improves adherence over CPAP in subjects with high nasal resistance.
A randomized double-blind control cross-over trial of 4 weeks each of CPAP versus CPAP in World Trade Center dust-exposed subjects with OSA stratified by nasal resistance measured by 4-Phase Rhinomanometry.
317 subjects with OSA (mean AHI4%=17±14/hr) were randomized. Overall, PAP adherence was poor, but adherence to CPAP (n=239, mean hours per night (95% CI)) = 1.97h (1.68, 2.26) was greater than to CPAP (n=249, 1.65h (1.39, 1.91); difference 0.31h (0.03, 0.6 ); p<0.05). Contrary to our hypothesis there was no correlation between nasal resistance and adherence to CPAP (r=0.098, p=NS) or CPAP(r=0.056, p=NS). There was no difference in adherence between CPAP and CPAP (mean Δ hours (95% CI)) in subjects with low resistance (0.33h (-0.10, 0.76)) or high nasal resistance (0.26h (-0.14, 0.66)). No significant differences were observed in any of the secondary outcomes between PAP modes.
Contrary to expectations, our data do not show better adherence to CPAP than to CPAP in subjects with high or low nasal resistance, and, show clinically insignificant better adherence overall with CPAP. Clinical Trial registered with Clinicaltrials.gov (NCT01753999).