CHICAGO – Metabolic syndrome is significantly more common in patients with psoriatic arthritis than in those with rheumatoid arthritis, based on data from nearly 2,000 adults.
Previous studies have suggested that metabolic syndrome is associated with "a state of chronic, low-grade inflammation," said Dr. Asena Bahce-Altuntas of Albert Einstein College of Medicine in New York.
"Since psoriatic arthritis [PsA] is characterized by inflammation of both skin and joints, we may be underestimating this cardiovascular risk in PsA," she said at the annual meeting of the American College of Rheumatology.
To compare the prevalence of metabolic syndrome in patients with PsA versus rheumatoid arthritis (RA), Dr. Bahce-Altuntas and her colleagues used data from the Consortium of Rheumatology Researchers of North America (CORRONA) registry, a prospective, observational cohort including 4,014 patients with PsA and 25,976 patients with RA in academic and private practices throughout the United States. Lipid profile data were available for 1,956 patients from the CORRONA registry: 294 with PsA and 1,662 with RA.
Overall, 27% of PsA patients met criteria for metabolic syndrome, compared with 19% of RA patients. In addition, several specific components of metabolic syndrome were significantly more common in PsA patients.
In particular, significantly more PsA patients than RA patients had triglycerides greater than 150 mg/dL (38% vs. 28%).
Significantly more PsA patients than RA patients were male (54% vs. 23%, respectively), and the mean age was significantly greater in RA patients than in PsA patients (62 years vs. 56 years, respectively). However, after age, sex, and ethnicity were controlled for, the odds of metabolic syndrome remained significantly higher for PsA patients (odds ratio, 1.44).
Metabolic syndrome was defined as a body mass index greater than 30 kg/m2 and any two of the following criteria: triglycerides greater than 150 mg/dL, HDL less than 40 mg/dL for men or less than 50 mg/dL for women, a diagnosis of hypertension, or a diagnosis of diabetes.
In a subanalysis of obese patients (133 PsA patients and 654 RA patients with a BMI greater than 30), the prevalence of metabolic syndrome remained significantly higher in PsA patients (60%) than in RA patients (49%), as did the prevalence of patients with triglycerides greater than 150 mg/dL (51% vs. 39%).
The study was limited by the relatively small sample of PsA patients, and by the modified metabolic syndrome criteria that may have underestimated the prevalence of metabolic syndrome in both groups, said Dr. Bahce-Altuntas.
However, the results suggest that metabolic syndrome and its components are significantly more common in PsA than in RA. "High triglycerides appear to drive the estimated increase in risk of metabolic syndrome in PsA vs. RA," she noted.
The combination of skin and joint inflammation in PsA may contribute to the increased frequency of metabolic syndrome in these patients, but more research is needed, Dr. Bahce-Altuntas said.
Meanwhile, "more intensive interventions to modify these risk factors are warranted in PsA patients in order to reduce cardiovascular morbidity and mortality," she said.
The following companies have supported CORRONA through contracted subscriptions over the past 2 years: Abbott, Amgen, AstraZeneca, Bristol-Myers Squibb, Centocor, Genentech, Lilly, Pfizer, and Roche. Dr. Bahce-Altuntas had no financial conflicts to disclose.