MIAMI – Diabetes mellitus, hypothyroidism, Cushing’s disease, and osteoporosis occur more frequently in people with psoriatic arthritis than in controls, a large cohort study reveals. Prevalence of these endocrine conditions was greater in a group of 3,161 patients with psoriatic arthritis, compared with 31,610 matched controls.
“We recommend that physicians should be aware of comorbid associations to provide comprehensive medical care to patients with psoriatic arthritis,” said Amir Haddad, MD, of the department of rheumatology at Carmel Medical Center in Haifa, Israel.
Dr. Haddad and his colleagues, however, found no significant differences in the prevalence of hyperthyroidism, hypo- and hyperparathyroidism, hyperprolactinemia, Addison’s disease, diabetes insipidus, pituitary adenoma, or acromegaly between groups in this retrospective, cross-sectional study.
They identified 1,474 men and 1,687 women diagnosed with psoriatic disease from 2000 to 2013 using the Clalit health services database in Israel. This group was a mean of 58 years old and 53% were women. Each patient was matched with 10 age- and gender-matched controls without psoriatic disease for the study.
“This is, to our knowledge, one of the largest real-life cohorts of psoriatic patient registries,” Dr. Haddad said at the annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).
In the psoriatic arthritis group versus controls, diabetes mellitus prevalence was 27.9% vs. 20.7%; for hypothyroidism it was 12.7% vs. 8.6%; and for Cushing’s disease it was 0.3% vs. 0.1%. All these differences were statically significant (P less than 0.0001). Osteoporosis prevalence also differed significantly between the psoriatic arthritis and control groups: 13.2% vs. 9.1% (P less than 0.001).
Greater awareness of nonskin and nonjoint comorbidities is important, Dr. Haddad said, because it can influence choice of therapy and management of patients with psoriatic arthritis.
The investigators also conducted univariate and multivariate regression analyses. Compared with controls, the results suggest psoriatic arthritis patients have a higher risk for diabetes mellitus (odds ratio, 1.48), hypothyroidism (OR, 1.56), and osteoporosis (OR, 1.52). The risk for Cushing’s disease was notably higher (OR, 5.31) in the univariate analysis.
Risks for these endocrine conditions remained higher for the psoriatic arthritis patients in a multivariate regression analysis as well. For example, risk for diabetes mellitus (OR, 1.30) remained after adjusting for age, gender, smoking, obesity, and steroid use. Risk of hypothyroidism (OR, 1.61) remained after adjusting for age and gender; risk of osteoporosis (OR, 1.50) after adjusting for age, gender, steroid use, and smoking; and risk of Cushing’s disease (OR, 3.79) after adjustment for age, gender, and steroid use.
The large, population-based cohort is a strength of the study. “We are now going back to see how many of these patients were seen by rheumatologists,” Dr. Haddad said. A lack of association with disease burden is a potential limitation, he added.
Thirty percent of patients were treated with biologics and about 67% with steroids. “That number treated with steroids seems high,” a meeting attendee commented. Dr. Haddad explained that it is the percentage ever treated with steroids, not necessarily currently on steroids.
In a separate session at the GRAPPA meeting addressing psoriatic disease treatment recommendations, an attendee asked about specific recommendations for comorbidities. For now, GRAPPA plans to include comorbidities within its overall recommendations, as it did in its most recent update, released in January 2016. A limited amount of data is a primary reason.
“As the evidence on comorbidities gets better, we may someday have separate recommendations for comorbidities,” said Laura Coates, MD, a clinical lecturer in rheumatology at the University of Leeds (England).
“The comorbidities are very important,” said Arthur F. Kavanaugh, MD, professor of medicine at the University of California, San Diego. “That’s trickier and deals with the international nature of GRAPPA. It’s hard to say, ‘Go see this specialist,’ because that might not be standard of care in that country.”
Dr. Haddad, Dr. Coates, and Dr. Kavanaugh reported having no relevant financial disclosures.