Prevalence and type II diabetes-associated factors in psoriatic arthritis.

Diabetes is a common cardiovascular risk factor in psoriatic arthritis (PsA). Although the prevalence of diabetes is high, the factors associated with it in PsA are poorly understood. We aimed to analyse the prevalence of type II diabetes and diabetes-associated factors in a hospital-based population with PsA. This cross-sectional study included 340 consecutive patients attended in a tertiary care hospital. The prevalence of diabetes was compared to that of 600 outpatients without inflammatory conditions. To analyse diabetes-associated factors, odds ratio (OR) values were calculated by conditional logistic regression analysis. Significant variables in the univariate analysis were then introduced in a multivariate analysis with a backward stepwise approach. Diabetes was more prevalent among PsA patients (13.8 vs. 5%, OR 2.8, 95% CI: 1.7-4.3, p < 0.0001). Diabetes-associated factors in the univariate analysis (p < 0.05) were the following: an age of onset of psoriasis > 40 years, an age of onset of arthritis > 40 years, a low educational level, family history of psoriasis, pustular psoriasis, high number of swollen joints during follow-up, hypertension, dyslipidemia, obesity, and cardiovascular events. After controlling for several confounders, diabetes was significantly associated with late-onset psoriasis (OR 8.2, 95% CI: 1.9-12.4, p = 0.002) and hypertension (OR 7.5, 95% CI: 1.5-13.3, p = 0.008). Diabetes risk should be carefully evaluated in patients with PsA whose psoriasis begins after 40 years.