title: Psoriasis carries an increased risk of venous thromboembolism: a Danish nationwide cohort study.
abstract: BACKGROUND
  Psoriasis is an immunoinflammatory disease associated with cardiovascular risk factors, atherothrombotic events, and hypercoagulability. Venous thromboembolism (VTE) is potentially lethal and shares risk factors with psoriasis, but the risk of VTE associated with psoriasis is unknown. The present study investigated the potential association between psoriasis and VTE.
  
  
  RESULTS
  Information from nationwide prospectively recorded registers of hospitalization, drug dispensing from pharmacies, socio-economic data, and causes of death was linked on an individual level. In an unselected nationwide cohort, we used multivariate Poisson regression models controlling for age, gender, comorbidity, concomitant medication, socio-economic data, and calendar year, to assess the risk of VTE associated with psoriasis. A total of 35,138 patients with mild and 3,526 patients with severe psoriasis were identified and compared with 4,126,075 controls. Patients with psoriasis had higher incidence rates per 1000 person-years of VTE than controls (1.29, 1.92, and 3.20 for controls, mild psoriasis, and severe psoriasis, respectively). The rate ratio (RR) of VTE was elevated in all patients with psoriasis with RR 1.35 (95% confidence interval [CI] 1.21-1.49) and RR 2.06 (CI 1.63-2.61) for mild and severe psoriasis, respectively. Exclusion of patients with malignancies, and censoring of patients undergoing surgery did not alter the results.
  
  
  CONCLUSIONS
  This nationwide cohort study indicates that patients with psoriasis are at increased risk of VTE. The risk was highest in young patients with severe psoriasis. Physicians should be aware that patients with psoriasis may be at increased risk of both venous and arterial thromboembolic events.
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Hellerup, Denmark. olahha01@geh.regionh.dk
authors.forename: Ole
authors.initials: O
authors.lastname: Ahlehoff
authors.forename: Gunnar Hilmar
authors.initials: GH
authors.lastname: Gislason
authors.forename: Jesper
authors.initials: J
authors.lastname: Lindhardsen
authors.forename: Mette Gitz
authors.initials: MG
authors.lastname: Charlot
authors.forename: Casper Haslund
authors.initials: CH
authors.lastname: Jørgensen
authors.forename: Jonas Bjerring
authors.initials: JB
authors.lastname: Olesen
authors.forename: Ditte-Marie
authors.initials: DM
authors.lastname: Bretler
authors.forename: Lone
authors.initials: L
authors.lastname: Skov
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.forename: Peter Riis
authors.initials: PR
authors.lastname: Hansen
mesh_terms: D017677:Age Distribution; D015982:Bias; D015331:Cohort Studies; D016001:Confidence Intervals; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011565:Psoriasis / Q000150:complications* / Q000453:epidemiology*; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000453:epidemiology* / Q000209:etiology*