Fig. 2

Changes in symptom scores, main spirometric variables and pulse oximetry in subjects with cystic fibrosis during glycine and placebo intake. All data are expressed as percentage of their respective baseline values. Symbols correspond to mean ± standard error of 13 patients who received 0.5 g/kg/day glycine (filled circles) and placebo (empty circles) during 8 weeks in random order. Statistical significance was assessed through paired Student’s t-test. The symptoms total score, sputum features and dyspnea perception were assessed by a Liker-type scale ranging from 1 (better) to 5 (worse). SpO₂ = peripheral blood oxygen saturation; FEV₁ = forced expiratory volume at the first second; FVC = forced vital capacity