Study of insulin resistance in patients with systemic lupus erythematosus and rheumatoid arthritis

Abstract

ObjectiveThe aim of the study was to study insulin resistance (IR) and pancreatic b-cell function in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and their relationship with disease activity.BackgroundIR is an important contributor to the increased cardiovascular risk attributed to the metabolic syndrome, a constellation of cardiovascular risk factors that includes central obesity, dyslipidemia, hypertension, and disturbed glucose metabolism, in patients with RA or SLE.Patients and methodsThe study included 35 SLE and 35 RA patients and 20 controls. Disease activity was assessed by Systemic Lupus Activity Measure score and Disease Activity Score-28. BMI, C-reactive protein, erythrocyte sedimentation rate, lipid profile, fasting glucose and insulin, and c-peptide were determined. The homeostasis model of assessment (HOMA) was used to evaluate IR and secretion.ResultsSLE patients had high-grade systemic inflammation, IR, and secretion compared with controls (P < 0.05). RA patients revealed high-grade systemic inflammation, IR, and secretion compared with controls (P < 0.001). Active SLE and RA patients were more insulin resistant than nonactive patients.ConclusionThe present study demonstrated that both SLE and RA patients had a higher IR and abnormal insulin secretion than age-matched apparently healthy controls. This conclusion was based on the measurement of fasting insulin concentration, HOMA IR, and HOMA b-cells. IR and abnormal insulin secretion were associated with markers for inflammation (erythrocyte sedimentation rate and C-reactive protein) and disease activity indices (Systemic Lupus Activity Measure and Disease Activity Score-28). Higher IR and abnormal insulin secretion were found in RA patients in comparison with SLE patients.