Exercise capacity in patients with psoriasis assessed by cardiopulmonary exercise testing: a case-control study

Background Psoriasis is a systemic inflammatory disease associated with cardiovascular and metabolic comorbidities. Although reduced physical activity is frequently reported in these patients, objective data on physiological exercise capacity remains limited. Objective To evaluate exercise capacity in patients with psoriasis using Cardiopulmonary Exercise Testing (CPET), the gold standard method, and compare the results with those of healthy controls. Methods This cross-sectional study included 32 patients with psoriasis (off systemic therapy for ≥6-months) and 33 age- and sex-matched healthy controls. Participants underwent symptom-limited CPET on a cycle ergometer. Disease severity was assessed using the Psoriasis Area and Severity Index (PASI), and Physician Global Assessment (PGA). Results Patients with psoriasis demonstrated significantly lower exercise capacity compared to controls. Peak VO₂, percentage of predicted peak VO₂, VO₂ at AT, and work rate were all significantly lower (all p < 0.01). Peak VO₂ showed significant negative correlations with BMI, PASI, and PGA (all p ≤ 0.001). In multiple linear regression analysis, age (β = -0.17, p = 0.017), BMI (β = -0.30, p = 0.007), and PASI score (β = -0.47, p = 0.001) were identified as independent predictors of peak VO₂, explaining 63.4% of its variance (R² = 0.634, p < 0.001). Study limitations The cross-sectional design and relatively small single-center sample limit causal inference. Conclusions Patients with psoriasis demonstrated reduced exercise capacity compared with healthy controls, and disease severity was independently associated with lower peak VO₂. However, due to the cross-sectional design and the potential influence of unmeasured cardiometabolic and lifestyle-related confounders, causality cannot be established, and further prospective studies are required.