Dysfunctional breathing in patients with moderate and severe obstructive sleep apnea: a cross sectional study

PURPOSE: The nocturnal breathing alterations among patients with obstructive sleep apnea (OSA) impact their daytime breathing mechanics. However, dysfunctional breathing remains under-recognized with limited evidence in these patients. The study aimed to examine the relationship between dysfunctional breathing (DB) and apnea hypopnea index (AHI) among patients with moderate and severe OSA. The secondary objective was to compare DB between patients with moderate and severe OSA. METHODS: A cross sectional study was performed at Manipal Hospital, Bangalore with 120 participants. The biomechanical component, biochemical component and patient reported symptoms of DB were assessed using manual assessment of respiratory motion (MARM), breath holding test (BHT) and self evaluation of breathing questionnaire (SEBQ), respectively. Correlation and regression analysis were used to determine the relationship between DB and AHI. Comparison of outcomes among individuals with moderate OSA and severe OSA was done. RESULTS: MARM volume showed non-significant negative correlation with AHI with ρ = -0.085. MARM Balance and ribcage motion showed significant correlation (p < 0.05) with ρ = 0.187 and ρ = 0.205, respectively. The BHT showed non-significant correlation (p > 0.05) with ρ = -0.105 and patient reported symptoms showed significantly positive correlation with ρ = 0.458. The regression model showed significant findings on adjusting for the potential confounders. Also, significantly deteriorated dysfunctional breathing outcomes were reported in patients with severe OSA. CONCLUSION: The DB outcomes showed marked relationship with the severity of OSA. Additionally, all the aspects of DB were substantially affected in individuals with severe OSA as compared to those with moderate OSA.