... COPD in our study, in contrast to cur-rent smokers, is supported by previous findings suggest-ing that the inflammatory effects of current smoking may mask the underlying o ngoing inflammatory ... only in ex-smokers, after the elimination of the confounding role of continuing smoking. In this study, we have used as a cut-off point for th eexpression of severe hyperinflation, a value of the ... pH, including the effect of drinking or eating [24], smoking [25,26],thepresenceofextrapulmonarycomponents[27] ,the dilution bias and the purging procedure in order toachieve the stability of the...