The Occurrence of Metabolic Risk Factors Stratified by Psoriasis Severity: A Swedish Population-Based Matched Cohort Study

PURPOSE: To assess the relative risk of metabolic risk factors in patients stratified by psoriasis severity compared with population controls. PATIENTS AND METHODS: A retrospective cohort study was conducted using national Swedish registers. Adult patients with psoriasis were selected if they had a dispensing of anti-psoriasis prescription (2007–2013) and at least one diagnosis within five years before the dispensing date. The patients with psoriasis were matched 1:10 to controls from the general population on birth year, sex, and county. The cohort was further divided into three disease severity groups (mild, moderate, or severe) based on their dispensed anti-psoriasis medication. Subjects were followed from the index date until censoring. We applied flexible parametric modeling to understand the risks of the incident comorbidities hypertension, hypercholesterolemia, and diabetes mellitus among patients with psoriasis from 6 months through 10 years. Hazard ratios and predicted risk (ie, 1 minus the survival probability) of comorbidities were reported. RESULTS: The hazard of hypertension, hypercholesterolemia, and diabetes mellitus is higher among psoriasis patients compared with population controls, and the hazard ratio increases with psoriasis severity. For example, HRs of hypertension for patients with mild, moderate, and severe psoriasis are 1.29 (95% CI: 1.27–1.32), 1.35 (95% CI: 1.32–1.38), and 1.73 (95% CI: 1.64–1.82), respectively. The predicted risk of hypertension, hypercholesterolemia, and diabetes mellitus among patients with severe psoriasis at year ten was 0.58 (95% CI: 0.56, 0.59), 0.33 (95% CI: 0.32, 0.35), and 0.21 (95% CI: 0.20, 0.23), respectively, while it was 0.42 (0.41, 0.43), 0.23 (0.22, 0.23), 0.11 (0.10, 0.11) among controls, respectively. The predicted risk at year ten was similar among patients with mild or moderate psoriasis. CONCLUSION: The HRs and predicted risks of metabolic risk factors are higher among patients with psoriasis compared with matched controls and are more prominent among the severe psoriasis group.