Why carry out this study?

To provide a very brief background about psoriatic arthritis, a diffuse chronic immune-mediated inflammatory spondyloarthropathy associated with psoriasis, and diabetes mellitus, the most common metabolic disorders in the industrial world.

Find the epidemiological association and pathogenic mechanisms linking psoriatic arthritis and diabetes mellitus.

Consider the effect of therapies for psoriatic arthritis on diabetes mellitus.

What was learned from the study?

Patients affected by psoriatic arthritis have a higher prevalence of diabetes mellitus compared with the general population.

The pathogenic link between psoriatic arthritis and diabetes mellitus is not fully understood, but some of the principal mediators could be TNF-α and adipokine.

Biological therapies for psoriatic arthritis have a neutral effect on glucose homeostasis and could be safely used in patients with diabetes mellitus. It is possible that some new therapies, including apremilast and anti-TNF-α, could improve diabetes mellitus based on their mechanism of action.