Association of IL-10 to coronary disease severity in patients with metabolic syndrome.

Background: Metabolic syndrome (MetS) is a group of risk factors that increase the risk for heart disease. Little is known about the role of IL-10 in the severity of coronary artery disease (CAD) in patients with MetS. We investigated plasma levels of IL-10 and other pro-inflammatory cytokines in patients with MetS with or without severe CAD.

Methods: Cross-sectional study with healthy and MetS individuals. IL-10 and other pro-inflammatory interleukins were analyzed in 90 subjects divided into 3 groups: group 1 (n = 30), patients with MetS without severe CAD; group 2 (n = 30), patients with MetS and severe CAD (history of myocardial infarction or revascularization performed through surgery or percutaneous transluminal coronary angioplasty with or without stent placement); and group 3 (n = 30), healthy individuals.

Results: Levels of IL-12 (p = .018), TNF-α (p = .007) and IL-6 (p = .010) were significantly higher in group 1 when compared to group 3 (p = .003; p = .002; p = .001, respectively). In addition, group 1 presented significantly higher levels of IL-12 (p = .019), TNF-α (p = .026) and IL-6 (p = .020) when compared to group 2. IL-10 levels were significantly higher in group 1 (p = .003) when compared to group 2 (p = .014) and group 3 (p < .001). Only the level of IL-10 was significant to explain the presence of severe CAD, as a protective factor (OR: 0.896; 95%CI: 0.818-0.981) in the logistic regression model.

Conclusions: Higher IL-10 levels in patients with MetS are associated with lower incidence of severe CAD, suggesting a protective effect through its anti-inflammatory activity even in the presence of higher levels of pro-inflammatory cytokines.