September 14, 2018
"This population-based study identified a 50% increase and 40% increased risk of T2D among an incident cohort of PsA patients compared with patients with psoriasis and those in the general population, respectively," write Neil McHugh, MBChB, MD, FRCP, FRCPath, from the University of Bath and Royal National Hospital for Rheumatic Diseases, Upper Borough Walls, Bath, United Kingdom, and colleagues.
As part of a large cohort study, the researchers identified 6783 patients (aged 18 - 89 years) with a new diagnosis of PsA. They matched the patients at a 1:4 ratio to two randomly selected cohorts: the first was a general population cohort with no PsA, psoriasis, or other inflammatory arthritides (n = 27,132), and the second was a psoriasis cohort with no diagnosis of PsA or other inflammatory arthritides (n = 27,132).
The incidence of T2D was significantly higher in the PsA cohort compared with the general population and the psoriasis cohorts (adjusted relative risk, 1.40 [95% confidence interval, 1.15 - 1.70] and 1.53 [95% confidence interval, 1.19 - 1.97], respectively).
The study authors also found "a 29% increase in risk of the combined cardiovascular diseases, a 27% increase in the risk of [ischemic heart disease,] and a 40% increase in the risk of [peripheral vascular disease] in PsA patients compared with the general population after taking into account other potential risk factors, but no increase in any of the cardiovascular outcomes compared with the psoriasis population."
Strengths of the study include the large number of patients with PsA enrolled; however, the researchers acknowledge study limitations such as the possibility for referral bias, insufficient follow-up time, and lack of data on PsA disease activity and treatment.
Although the reason for this association between PsA and T2D is still not clear, the authors suggest that factors such as the additional inflammatory burden associated with arthritis, diet, microbiome, or genetic factors may play a role.
Results of the present study "support the proposal in existing clinical guidelines that in order to reduce cardiovascular risk in patients with PsA, it is important to treat inflammatory disease as well as to screen and treat traditional risk factors early in the disease course," conclude McHugh and colleagues.
The National Institute for Health Research provided funding for this study. The authors have disclosed no relevant financial relationships.