Psoriasis and the risk of diabetes: A prospective population-based cohort study

Background: Data evaluating the impact of objectively measured psoriasis severity on type 2 diabetes mellitus (T2DM) risk are lacking. Objective: To determine the risk for T2DM in patients with psoriasis compared with that in adults without psoriasis, stratified by categories of directly assessed body surface area (BSA) affected by psoriasis. Methods: A prospective, population-based, cohort study from the United Kingdom in which 8124 adults with psoriasis and 76,599 adults without psoriasis were followed prospectively for approximately 4 years. Results: There were 280 incident cases of diabetes in the psoriasis group (3.44%) and 1867 incident cases of diabetes in those without psoriasis (2.44%). After adjustment for age, sex and body mass index, the hazard ratios for development of incident diabetes were 1.21 (95% confidence interval [CI], 1.01-1.44), 1.01 (95% CI, 0.81-1.26), and 1.64 (95% CI, 1.23-2.18) in the groups with 2% or less of their BSA affected, 3% to 10% of their BSA affected, and 10% or more of their BSA affected compared with in the groups without psoriasis, respectively (P = .004 for trend). Worldwide, we estimate an additional 125,650 new diagnoses of T2DM per year in patients with psoriasis as compared with in those without psoriasis. Limitations: Relatively short-term follow-up and exclusion of prevalence cases, which may have masked associations in patients with less extensive psoriasis. Conclusion: Clinicians may measure BSA affected by psoriasis to target diabetes prevention efforts for patients with psoriasis.