Effects of insulin therapy on inflammatory mediators in infants undergoing cardiac surgery with cardiopulmonary bypass

To determine whether insulin administration modulates the systemic inflammatory response in infants undergoing cardiac surgery with cardiopulmonary bypass, 60 infants undergoing cardiopulmonary bypass were randomly assigned into a routine therapy group or to an intensive insulin therapy group with 30 infants in each group. Plasma IL-1β, IL-6, IL-10, and TNF-α levels were determined before anesthesia, at the initiation of cardiopulmonary bypass, and at 0, 6, 12, 24, and 48 h after cardiopulmonary bypass. Nuclear factor-κBp65 expression and IκB expression in peripheral blood mononuclear cells were also measured by Western blot analysis. TNF-α, IL-1β, IL-6, and IL-10 levels were all elevated after the initiation of cardiopulmonary bypass. However, TNF-α, IL-1β, and IL-6 levels were significantly attenuated in the intensive insulin therapy group compared to those in the routine therapy group after initiation of cardiopulmonary bypass (p < 0.05 or <0.01). Meanwhile, plasma IL-10 levels were significantly higher in the intensive insulin therapy group than in the routine therapy group after initiation of cardiopulmonary bypass (p < 0.05 or <0.01). Accordingly, Nuclear factor-κBp65 expression and IκB expression were significantly increased after initiation of cardiopulmonary bypass in both groups (p < 0.05 or <0.01). The expression of Nuclear factor-κBp65, which induces the transcription of pro-inflammatory cytokines was significantly attenuated in the intensive insulin therapy group (p < 0.05 or <0.01). Meanwhile, the expression of IκB, an inhibitor of NF-κB, was significantly higher in the intensive insulin therapy group (p < 0.05 or <0.01). These results suggested that intensive insulin therapy may attenuate the systemic inflammatory response in infants undergoing cardiopulmonary bypass.