Functional effects of long term ICS treatment in controlled asthma

Background: Goal of asthma management is the “control” of the disease,monitoring symptoms and FEV1orPEF. However, in controlled asthma the persistence of a long term asymptomatic airway inflammation may lead to an accelerated functional decline. Aim: To estimate the protective effect of a long term treatment with low dosage of ICS on functional parameters in controlled asthma Methods: 98 asthmatic pts with ACT (Asthma Control Test) >20, nonsmokers were enrolled in a 3 yrs controlled randomized trial. Patients were divided in 2 groups: group A (49) (ICS) receiving a continuous treatment with inhaled beclomethasone MDI100mcg twice/die +inhaled salbutamol as needed; group B (49) (control) treated with inhaled salbutamol as needed. Step up therapy was performed as recommended by guidelines. Every 3 months, measures of FEV1, FVC, MEF, RV, TLC, FRC, ACT, PD20 (methacoline) were performed. Primary endpoint were: variation of functional parameters, PD20, and ACTscore Results: Δ was the difference between time 0 and at 3yrs. Significant difference was reported for RV/TLC: A 30.9±3.2 (Δ+0.5), B 33.7±3.3 (Δ+2.5); PD20 (mcg): A 1232.5±301 (Δ+699), B 656.74±280 (Δ+55); FEV1/FVC at the attainment of PD20: A 64.2%±2.9 (Δ+0.4), B 67.6%±3.0 (Δ+4.9). No significant differences reported for FEV1 (A 3.94, B 3.86), FVC (A 5.27, B 5.15), FEV1/FVC (A 74.7%, B 74,9%), MEF25% (A 1.30, B 1.09), ACTscore (A 20.1, B 19.7), side effects (A 8, B 9). Conclusion: A long term treatment with low dosage of ICS and the reduction of airway responsiveness are bound to a better preservation of the respiratory function in controlled asthma. It is probably due to a better control of a slight air trapping and asymptomatic involvement of small airways, as suggested by the greater decrease of FVC at PD20 in non treated group.