Anti tumour necrosis factor alpha therapy improves insulin sensitivity in normal-weight but not in obese patients with rheumatoid arthritis Full Text
Arthritis Research & Therapy, 07/06/2012
Stavropoulos–Kalinoglou A et al. – Anti–TNFalpha therapy, through controlling inflammation, seems to improve insulin sensitivity in normal–weight Rheumatoid Arthritis (RA) patients with insulin resistance, but is not sufficient to achieve the same beneficial effect in obese RA patients with insulin resistance.Methods
- Patients who were normal–weight with IR (N+IR) or obese with IR (O+IR), and embarked on anti–TNFalpha treatment participated.
- Assessments included body mass index (BMI), insulin sensitivity (Homeostasis Model Assessment of insulin resistance, HOMA and the Quantitative Insulin sensitivity Check Index, QUICKI), RA disease characteristics before and following 6 months of anti–TNFalpha treatment.
- Their results were compared to matched (for age, gender, BMI, disease duration and smoking status) normal–weight patients without IR (N–IR) and obese without IR (N–IR) respectively.
- In total, 32 patients were assessed for this study, with 8 in each group.
- Following 6 months of treatment, disease activity was significantly reduced in all groups (P<0.05) to a similar extent (P for differences between groups >0.05 in all cases).
- In the total population, changes in HOMA (mean reduction at 6m = –0.2 +/–0.1; P=0.088) and QUICKI (mean increase at 6m = 0.03 +/–0.022; P=0.092) after treatment were not statistically significant, though a trend towards improvement was observed.
- However, N+IR patients showed a significant decrease in HOMA (mean reduction at 6m = –0.54+/–0.2; P=0.002) and increase in QUICKI (mean increase at 6m = 0.046+/–0.02; P=0.011).
- These changes were significantly different compared to the other groups (P<0.05 in all cases).
- Multivariable analyses showed that the change in Erythrocyte Sedimentation Rate (ESR), and the change in C–Reactive Protein (CRP) associated with the improvement in HOMA (ESR: F1–7= 5.143, P=0.019; CRP: F1–7= 3.122, P=0.022) and QUICKI (ESR: F1–7= 3.814, P=0.021; CRP: F1–7= 2.67; P=0.041) only in the N+IR group.