FROM THE JOURNAL OF RHEUMATOLOGY
Psoriatic arthritis raises the risk of type 2 diabetes, and the risk correlates with higher disease activity, according to Canadian investigators.
They reviewed 1,065 patients free of diabetes when they entered treatment at the University of Toronto psoriatic arthritis (PsA) clinic during 1978-2014; 73 developed type 2 diabetes.
Morning tender joint count (hazard ratio, 1.53), morning erythrocyte sedimentation rate (HR, 1.21), and body mass index (HR, 1.09) predicted diabetes by statistically significant margins. The age-standardized prevalence of diabetes was 43% higher in PsA patients than in the general population of Ontario.
“This finding highlights the need to screen for DM [diabetes mellitis] in patients with PsA, especially in those with more active joint disease and elevated inflammatory markers. The control of inflammation may reduce the risk of developing DM,” said investigators led by Lihi Eder, MD , a research fellow at the University of Toronto (J Rheumatol. 2017 Feb 1; doi: 10.3899/jrheum.160861 ).
Psoriasis has been linked to diabetes before; the association with PsA, at least until now, has been less well supported.
Chronic inflammation could be part of the issue; it’s also been linked before to diabetes, independently of insulin resistance and obesity. More severe psoriasis, as indicated by higher Psoriasis Area and Severity Index scores, was associated with diabetes risk in the study, but fell out as an independent predictor after adjustment for obesity and other confounders.
Also, “part of the increased risk of cardiovascular in PsA may be attributed to the higher prevalence of DM, which was found in our study,” the investigators said.
Data about smoking, metabolic syndrome, and C-reactive protein weren’t routinely collected in the earlier years of the cohort, so could not be assessed. “It is possible that some of these variables could have modified the identified link between the extent of inflammation and DM risk,” they said.
Patients were 54 years old on average at baseline, and 56% were men. The mean duration of psoriasis at clinic presentation was 15.4 years, and of psoriatic arthritis 6.5 years. The mean duration of follow-up was 9.1 years.
Dr. Eder was supported by the Krembil Foundation and a Canadian Institutes of Health Research fellowship award.
