Background TNFa plays a key role in the pathogenesis of both rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Recent data support the hypothesis that TNFa is involved in the regulation of carbohydrate and lipid metabolism and it is well know that patients with RA and PsA present a high prevalence of metabolic syndrome and insulin resistance.
Objectives The aim of this study is to evaluate the effects of three different anti TNFa drugs on lipid profile, insulin resistance and circulating levels of various adipokines in a cohort of patients with RA and PsA and the possible relationship with activity disease
Methods We evaluated 25 consecutive patients fulfilling the 2010 revised American College of Rheumatology criteria for RA and 66 consecutive patients age and sex matched fulfilling the CASPAR criteria for PsA. At time of recruitment all patients were treated with methotrexate (10 – 15 mg/weekly) and low dose of prednisone (up to 7,5 mg/day). PsA and RA patients were randomly assigned to receive adalimumab (ADA), infliximab (IFX) or etanercept (ETN). For each group we evaluated the effect of treatment on body mass index (BMI), lipid profile, atherogenic index, insulin resistance index (HOMA2-IR), insulin sensitivity index (QUICKI), circulating levels of adipokines (resistin, leptin, adiponectin) and Framingham cardiovascular risk score at baseline (T0) and after 3 (T1) and 6 (T2) months and we correlated these data with disease activity (DAS28).
Results At baseline we found that compared to PsA, RA patients presented a significantly higher disease activity (p<0,01), atherogenic index and insulin resistance (p<0,05 and p<0,01 respectively), whereas serum levels of adiponectin were significantly lower (p<0,05). No differences in BMI, insulin sensitivity index, Framingham cardiovascular risk score, serum lipid profile and circulating levels of resistin and leptin were observed between AR and PsA patients.
Both in RA and in PsA patients the activity disease at baseline positively correlated with atherogenic index and circulating levels of leptin and resistin (r=0,62, p<0,01); conversely, a negative correlation was observed at baseline between disease activity and circulating levels of adiponectin (r=-0,58, p<0,01). Both in RA and PsA patients ADA, IFX and ETN induced a significant reduction of atherogenic index (p<0,05 both at T1 and T2), insulin resistance (p<0,05 both at T1 and T2) and serum levels of leptin and resistin (p<0,01 both at T1 and T2); this reduction positively correlated with the reduction of disease activity. On the other hand, circulating levels of adiponectin and insulin sensitivity index significantly increased after treatment with ADA, IFX and ETN (p<0,05 at T1, p<0,01 at T2) and presented an inverse relationship with the disease activity. No differences were found between different anti TNFa treatments in the two group of patients.
Conclusions These preliminary data confirm the hypothesis that treatment with anti TNFa biologic drugs can positively affect the lipid metabolism, the atherogenic index and the insulin resistance profile in RA and PsA patients.
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Disclosure of Interest None declared