Background: Upper airway edema might contribute to pharyngeal collapsibility and account for the high prevalence of obstructive sleep apnea (OSA) in patients with heart disease. The aim of this study was to evaluate if intensive unloading with diuretics improves sleep-disordered breathing and increases pharyngeal caliber in patients with severe OSA and diastolic heart failure.
Methods: Fifteen patients with severe OSA, hypertension, and diastolic heart failure were hospitalized to receive IV furosemide, 20 mg, and spironolactone, 100 mg, bid for 3 days. Polysomnography was performed for assessment of apnea-hypopnea index (AHI), acoustic pharyngometry was performed for assessment of the oropharyngeal junction (OPJ) area, and forced midinspiratory flow (FIF(50)), forced midexpiratory flow (FEF(50))/FIF(50) percentage, and exhaled nitric oxide (FeNO) were measured before and after diuretic treatment.
Results: Diuretic treatment produced a significant decrease in body weight, BP, and AHI (from 74.89 +/- 6.95 to 57.17 +/- 5.40/h, p < 0.001), associated with an improvement in OPJ area (from 1.33 +/- 0.10 to 1.78 +/- 0.16 cm(2), p = 0.007), FIF(50) (from 3.16 +/- 0.4 to 3.94 +/- 0.4 L/s, p = 0.006), and FEF(50)/FIF(50) percentage (from 117.9 +/- 11.8 to 93.15 +/- 10.1%, p = 0.002). Weight loss was significantly related to the decrease of AHI (R = 0.602; p = 0.018), to the increase of FIF(50) (R = 0.68; p = 0.005), and to the decrease of FEF(50)/FIF(50) (R = 0.635; p = 0.011).
Conclusions: These findings suggest that pharyngeal edema contributes to sleep-disordered breathing in obese patients with severe OSA, hypertension, and diastolic heart failure. Upper airway edema may contribute to the frequent occurrence of OSA in patients with heart disease.