Alveolar-Derived Exhaled Nitric Oxide Is Reduced in Obstructive Sleep Apnea Syndrome

Exhaled Breath Analysis and Sleep

“…11,15,16 In all studies on pH, this marker was lower in EBC of OSAS patients compared to controls, correlated with AHI, and increased after one month of daily use of CPAP. Another largely studied inflammatory marker in OSAS is leukotriene (LT)-B4.…”

Long-Term Continuous Positive Airway Pressure Therapy Normalizes High Exhaled Nitric Oxide Levels in Obstructive Sleep Apnea

“…4,[23][24] The results we observed in our study are consistent with the current evidence showing elevated cytokines and inflammatory markers in exhaled breath as well as upper airway tissues of OSA patients. 4,[9][10][11][12][13][14][15][16][17]23,[25][26][27][28] Salerno et al and Devouassoux et al detected increased neutrophils and reduced macrophages in the induced sputum of OSA patients. 27,28 The latter study also observed a concurrent higher interleukin-8 concentration in the induced sputum specimen of these patients.…”

“…[31][32][33] In the study by Devouassoux et al, 28 one week of CPAP use in OSA patients was found to induce increased airway hyperresponsiveness to methacholine with increased NO levels in exhaled breath and neutrophil concentration in induced sputum. In the study by Foresi et al, 10 increased alveolar NO concentrations were normalized after two nights of CPAP treatment, suggestive of restoration of endothelial function in OSA patients, although FENO remained unchanged following the two nights of CPAP therapy. However, we note that in that study, the baseline FENO levels taken in the morning were not different from the healthy controls, and 18 of their subjects had underlying arterial hypertension.…”

“…5,6 Prior studies that have evaluated the FENO levels in OSA have shown inconsistent results. [7][8][9][10][11][12][13][14][15][16][17] Specifi cally, studies have shown no difference, 8,10 mild increase, 13 or signifi cant increases in FENO 7,9,11,12,14,16,17 compared to controls. Post-vs. pre-sleep FENO was signifi cantly increased in one study 7 but unchanged in another.…”

“…[7][8][9][10][11][12][13][14][15][16][17] Part of the problem could have been patient selection or the use of old technology and methodology. With the latest generation portable FENO analyzer, we demonstrated a rise in FENO levels following sleep in adult OSA patients reflecting increased UAWI that were not present in healthy controls with normal airways.…”