Supplementary Material for: Impaired Pulmonary Function in Patients with Psoriasis

Background: Psoriasis is associated with chronic obstructive pulmonary disease. There is no study on the spirometric pulmonary function testing in patients with psoriasis. Objective: The aim of this study was to compare the spirometric parameters in patients with psoriasis and controls. Methods: 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 (FEV₁%), forced expiratory flow at 25-75% of FVC (FEF_25-75%), and FEV₁/FVC ratio, was performed in all study subjects. Results: The mean FEV₁/FVC ratio and FEF_25-75% were significantly lower in the psoriasis patients than in the controls (82.4 ± 6.3 vs. 90.7 ± 10.7, p < 0.001, and 86.7 ± 24.2 vs. 94.8 ± 23.0, p = 0.04, respectively). Both FEV₁/FVC ratio and FEF_25-75% were significantly associated with the presence of psoriasis (p < 0.001 and p = 0.029, respectively). Conclusion: Psoriasis patients had lower mean FEV₁/FVC ratios and FEF_25-75%, compared with the control subjects. FEV₁/FVC and FEF_25-75% are independently associated with the presence of psoriasis.