Supplementary Material for: Impaired Pulmonary Function in Patients with Psoriasis D.D.Balci E.Celik S.Genc M.M.Çelik M.U.Inan 2017 <p><b><i>Background:</i></b> Psoriasis is associated with chronic obstructive pulmonary disease. There is no study on the spirometric pulmonary function testing in patients with psoriasis. <b><i>Objective:</i></b> The aim of this study was to compare the spirometric parameters in patients with psoriasis and controls. <b><i>Methods:</i></b> Ninety-six patients with psoriasis and 60 sex- and age-matched control subjects were included in this study. Spirometric pulmonary function testing, including percent forced vital capacity (FVC%), percent forced expiratory volume in the 1st second (FEV<sub>1</sub>%), forced expiratory flow at 25-75% of FVC (FEF<sub>25-75%</sub>), and FEV<sub>1</sub>/FVC ratio, was performed in all study subjects. <b><i>Results:</i></b> The mean FEV<sub>1</sub>/FVC ratio and FEF<sub>25-75%</sub> were significantly lower in the psoriasis patients than in the controls (82.4 ± 6.3 vs. 90.7 ± 10.7, <i>p</i> < 0.001, and 86.7 ± 24.2 vs. 94.8 ± 23.0, <i>p</i> = 0.04, respectively). Both FEV<sub>1</sub>/FVC ratio and FEF<sub>25-75%</sub> were significantly associated with the presence of psoriasis (<i>p</i> < 0.001 and <i>p</i> = 0.029, respectively). <b><i>Conclusion:</i></b> Psoriasis patients had lower mean FEV<sub>1</sub>/FVC ratios and FEF<sub>25-75%</sub>, compared with the control subjects. FEV<sub>1</sub>/FVC and FEF<sub>25-75%</sub> are independently associated with the presence of psoriasis.</p>