Adiponectin and resistin serum levels in non-diabetic ankylosing spondylitis patients undergoing TNF-α antagonist therapy

The objective of this paper is to assess if disease activity, systemic inflammation and metabolic syndrome are potential determinants of circulating adiponectin and resistin levels in ankylosing spondylitis (AS) patients undergoing TNF-α antagonist therapy. We investigated adiponectin and resistin serum concentrations in a series of 29 non-diabetic AS patients without history of cardiovascular (CV) events that were treated with the TNF-α antagonist infliximab, immediately prior to an infliximab infusion. Adipokine levels were also determined immediately after administration of an infliximab dose. A significant correlation between adiponectin concentrations and insulin sensitivity (QUICKI at the time of the study) was seen (r=0.384; p=0.05). Also, a marginally significant negative correlation between adiponectin serum levels and the body mass index was observed (r=-0.367; p=0.07). Circulating adiponectin and resistin concentrations did not correlate with disease duration, erythrocyte sedimentation rate, C-reactive protein, BASDAI or VAS at the time of the study. However, AS patients with hip involvement or synovitis and/or enthesitis in other peripheral joints had higher adiponectin concentrations than those who did not have these complications (p-value for both comparisons =0.01). Adiponectin and resistin levels did not change upon infliximab administration. The present study shows that in non-diabetic patients with AS on treatment with infliximab adiponectin and resistin serum levels do not correlate with disease activity. Nevertheless, adiponectin concentration correlates with insulin sensitivity. This finding raises the possibility that low circulating adiponectin concentrations may be involved in the pathogenesis of the CV disease in AS.