The relationship between IL-10 levels and cardiovascular events in patients with CKD.

BACKGROUND AND OBJECTIVES: Cardiovascular disease is the leading cause of death in patients with CKD. IL-10 is considered an antiatherosclerotic cytokine. However, previous studies have failed to observe an association between IL-10 and cardiovascular disease in CKD. This study aimed to evaluate whether serum IL-10 levels were associated with the risk of cardiovascular events in CKD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Four hundred three patients with stages 1-5 CKD were followed for a mean of 38 (range=2-42) months for fatal and nonfatal cardiovascular events. IL-10 and IL-6 were measured at baseline together with surrogates of endothelial function (flow-mediated dilatation) and proinflammatory markers (high-sensitivity C-reactive protein and pentraxin-3). The association between IL-10 and flow-mediated dilatation through linear regression analyses was evaluated. The association between IL-10 and the risk of cardiovascular events was assessed with Cox regression analysis. RESULTS: IL-10, IL-6, high-sensitivity C-reactive protein, and pentraxin-3 levels were higher among participants with lower eGFR. Both fatal (25 of 200 versus 6 of 203 patients) and combined fatal and nonfatal (106 of 200 versus 23 of 203 patients) cardiovascular events were more common in patients with IL-10 concentration above the median. Flow-mediated dilatation was significantly lower in patients with higher serum IL-10 levels, but IL-10 was not associated with flow-mediated dilatation in multivariate analysis. Kaplan-Meier survival curves showed that patients with IL-10 below the median value (<21.5 pg/ml) had higher cumulative survival compared with patients who had IL-10 levels above the median value (log-rank test, P<0.001). CONCLUSIONS: IL-10 levels increase along with the reduction of kidney function. Higher serum IL-10 levels were associated with the risk of cardiovascular events during follow-up. We speculate that higher IL-10 levels in this context signify an overall proinflammatory milieu.