Increased leukotriene B4 plasma concentration in type 2 diabetes individuals with cardiovascular autonomic neuropathy

Background and aim A low-grade inflammation is associated with cardiac autonomic neuropathy (CAN) and increased concentration of leukotriene B4 (LTB4) was found in individuals with type 1 diabetes and definitive CAN. This cross-sectional study evaluated plasma concentration of LTB4 and of other inflammatory mediators, namely, tumor necrosis factor (TNF), interleukin (IL)1B, and IL10 in individuals with type 2 diabetes (T2D) and different degrees of CAN, and correlated these inflammatory mediators with the degree of glycemic control and with a surrogate marker of insulin resistance. Methods TNF, IL1B, IL10 and LTB4 plasma concentrations were measured in 129 T2D subjects (62% women with [median] age of 63 years, disease duration of 8 years and HbA1c of 7.3%) with or without CAN. The Lipid accumulation product index was used as a surrogate marker of insulin resistance. Results LTB4 concentration was significantly higher in those presenting incipient CAN (69.7 +/- 16.6 pg mL(-1)) and definitive CAN (71.5 +/- 15.7 pg mL(-1)) versus those without CAN (57.0 +/- 13.9 pg mL(-1)). The groups without CAN and with incipient CAN were pooled (group without definitive CAN) and compared to those with definitive CAN. LTB4 concentration was higher in the latter group, as well as TNF concentration, while IL10 concentration was lower in this group. After adjustment for confounding variables, only LTB4 concentration remained significantly different between the groups with and without definitive CAN. Plasma concentration of LTB4 did not correlate with the degree of glycemic control. After sorting the participants by sex, a borderline weak correlation was found between LTB4 and the Lipid accumulation product index in women. Conclusion In the T2D setting, circulating LTB4 concentration seems to be associated with cardiovascular dysautonomia.