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

Data evaluating the impact of objectively measured psoriasis severity on type 2 diabetes mellitus (T2DM) risk are lacking. 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. 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. 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. Relatively short-term follow-up and exclusion of prevalence cases, which may have masked associations in patients with less extensive psoriasis. Clinicians may measure BSA affected by psoriasis to target diabetes prevention efforts for patients with psoriasis.