Insulin resistance as a risk factor for subclinical atherosclerosis in rheumatoid arthritis

BackgroundInsulin resistance (IR) is strongly associated with systemic inflammation. Insulin resistance is known to be increased in patients with rheumatoid arthritis (RA) and has been shown to be a risk factor for both clinical cardiovascular disease and subclinical atherosclerosis.Aim of the workTo study the relationship between insulin resistance, disease activity and subclinical atherosclerosis in RA patients.Patients and methodsForty RA patients and twenty age and sex matched healthy individuals as controls were included. Patients with diabetes mellitus, obesity and hypertension were excluded. Fasting plasma sugar and serum insulin were done, RA disease activity was assessed using the disease activity score (DAS28) and IR was evaluated by the homeostasis model assessment (HOMA2). Carotid artery intima media thickness (IMT) was evaluated using ultrasound.ResultsRA patients had significantly higher erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) positivity, fasting plasma sugar and fasting serum insulin, HOMA2-IR levels than the controls. IR was present in 33 (82.5%) RA patients while it was present in only one (10%) of the controls (p = 0.001). RA patients with IR had significantly longer disease duration (p = 0.003), higher disease activity (p = 0.000), greater carotid IMT (p = 0.000), and more carotid plaques (p = 0.043) than those without insulin resistance. RA patients with increased IMT had significantly longer disease duration (p = 0.002), higher DAS28 score (p = 0.000) and higher HOMA2-IR (p = 0.000) than those with normal IMT.ConclusionsIn RA patients, IR significantly correlated with both disease activity and disease duration. Our study pointed out a significant association between IR and subclinical atherosclerosis in RA.