Effects of Salmeterol and Fluticasone Propionate Combination versus Fluticasone Propionate on Airway Function and Eosinophilic Inflammation in Mild Asthma

ABSTRACTBackgroundSalmeterol and fluticasone propionate combination (SFC) provides better asthma control than fluticasone propionate (FP) alone, however, little is known on the effects of differential treatments on airway function and inflammation in patients with mild asthma.MethodsWe randomized 27 mild persistent asthma patients treated with the equivalent of 400 μg beclomethasone dipropionate to receive SFC (50/100 μg, 13 patients) or FP (100 μg, 14 patients) twice daily for 8 weeks. We compared the effects of SFC and FP on pulmonary function assessed by spirometry and impulse oscillometry (IOS), eosinophil percentage of induced sputum and serum, and with asthma symptoms and control after each treatment.ResultsWe observed that SFC significantly improved forced expiratory volume in one second (p < 0.05), IOS measurements of total resistance R5 (p < 0.01), central resistance R20 (p < 0.05), and distal reactance X5 (p < 0.01) compared with FP. The percentage of eosinophils in sputum, but not in serum, decreased significantly more in the SFC group than in the FP group (p < 0.05). There was also a significant improvement in symptom control in the SFC group (p < 0.05).ConclusionsThese findings suggest that SFC is more useful than FP in mild asthma cases. The clinical benefit of SFC provides evidence that IOS and induced sputum allows for the detection of changes in airway function and inflammation.