(HealthDay News) — Patients with rheumatoid arthritis have elevated insulin resistance, but this is not associated with increased atherosclerosis risk, according to a study published in Arthritis & Rheumatology.
Jon T. Giles, MD, MPH, from Columbia University in New York City, and colleagues compared insulin resistance (estimated using the homeostatic model [HOMA-IR]) between 95 patients with rheumatoid arthritis and 98 demographically-matched controls without rheumatoid arthritis.
The average HOMA-IR levels were 31% higher in the rheumatoid arthritis group, regardless of strata of demographic or cardiometabolic risk factors, the researchers found.
In the control group, HOMA-IR was strongly and significantly associated with C-reactive protein (CRP) and interleukin-6 (IL-6), but this association was weaker in the rheumatoid arthritis group. Higher HOMA-IR correlated with rheumatoid factor positivity in men and women, and with prednisone use in women, among those with rheumatoid arthritis.
Higher HOMA-IR correlated with all assessed subclinical atherosclerosis measures in the control group before adjustment; after adjustment for cardiovascular (CV) risk factors, the correlations were attenuated and were no longer statistically significant.
Over an average of 3.2 years of follow-up, neither baseline nor average HOMA-IR correlated with change in any measures of atherosclerosis among the rheumatoid arthritis patients.
“Although [insulin resistance] was higher in [rheumatoid arthritis] than in non-[rheumatoid arthritis] controls, higher levels may not independently impart additional atherosclerosis risk,” the researchers wrote.