Relationships of adiponectin with markers of systemic inflammation and insulin resistance in infants undergoing open cardiac surgery

Abstract

Background: Insulin resistance and systemic inflammation frequently occur in infants undergoing cardiac surgery with cardiopulmonary bypass, while adiponectin has been demonstrated to have insulin-sensitizing and anti-inflammatory properties in obesity and type 2 diabetes mellitus. In this prospective study, we aimed to investigate the association of adiponectin with insulin resistance and inflammatory mediators in infants undergoing cardiac surgery with cardiopulmonary bypass.

Methods and results: From sixty infants undergoing open cardiac surgery, blood samples were taken before anesthesia, at the initiation of cardiopulmonary bypass and at 0, 6, 12, 24, and 48 hours after the termination of cardiopulmonary bypass. Plasma interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF- α ), and adiponectin levels were assessed in blood samples. Insulin resistance was measured by assessment of the insulin requirement to maintain euglycaemia and repeated measurements of an insulin glycaemic index. Insulin glycaemic index, IL-6, and TNF- α increased up to 3-8-fold 6 h after the operation. Adiponectin is negatively correlated with markers of systemic inflammation 6 h after CPB.

Conclusions: Although the level of serum adiponectin decreased significantly, there was a significant inverse association of adiponectin with markers of systemic inflammation and insulin resistance in infants undergoing open cardiac surgery.

Figure 1

Changes in blood glucose levels, insulin levels, and insulin glycaemic index in the perioperative period. Reported significances (*P < 0.05, **P < 0.01 were calculated using pairwise comparisons with the preoperative level within a repeated measurement analysis of variance model for the respective parameter at different time points). The error bars designate the standard deviation (CPB, cardiopulmonary bypass; T: time; T1: before anesthesia; T2: initiation of CPB; T3: termination of CPB; T4: 6 h after CPB; T5: 12 h after CPB; T6: 24 h after CPB; T7: 48 h after CPB).

Figure 2

Pre- and postoperative TNF-α and IL-6 (*P < 0.05, **P < 0.01 compared with basal levels). The error bars designate standard deviation. IL-6 and TNF-α levels are higher than basal levels and did not normalize within the study period ((a) and (b)). (CPB: cardiopulmonary bypass; T: time; T1: before anesthesia; T2: initiation of CPB; T3: termination of CPB; T4: 6 h after CPB; T5: 12 h after CPB; T6: 24 h after CPB; T7: 48 h after CPB).

Figure 3

Changes in adiponectin levels in the perioperative period. Reported significances (*P < 0.05 was calculated using pairwise comparisons with the preoperative level within a repeated measurement analysis of variance model for the respective parameter at different time points). The error bars designate the standard deviation (CPB: cardiopulmonary bypass; T: time; T1: before anesthesia; T2: initiation of CPB; T3: termination of CPB; T4: 6 h after CPB; T5: 12 h after CPB; T6: 24 h after CPB; T7: 48 h after CPB).

Figure 4

Correlations of adiponectin at T4 (6 h after CPB) with IL-6 (a), TNF-α (b), and insulin glycaemic index (c). Pearson's correlation coefficient (r) and P values of the corresponding significance test are both presented.