Association Between Serum Free Fatty Acids and Total Bilirubin Concentrations in Bosnian Individuals with Diabetes Mellitus Type 2

Serum bilirubin concentrations show antilipolytic effect on free fatty acids metabolism (FFA), and there are indications that FFA levels interfere with bilirubin metabolism. Recent studies have been reported that bilirubin is reversibly associated with increased adiposity and impaired insulin sensitivity caused by elevated FFA levels and that increased concentrations of these bioactive lipid metabolites are significantly associated with the risk of developing Type 2 Diabetes (T2D). The aim of this work was to examine the potential association of serum concentrations of various types of FFA (saturated, SFA and polyunsaturated, PUFA) and total bilirubin with T2D. This study included 145 participants, of which 54 were controls, 55 T2D patients, 12 prediabetics, and 24 were non-treated and newly diagnosed with T2D, both gender. Biochemical variables and total bilirubin levels were measured with IFCC methods by using the chemical analyzer VITROS 350 while FFA levels were determined by gas chromatography analysis. The results showed a significant difference in levels of glucose, glycated hemoglobin (HbA1c), total bilirubin, lipid profile (cholesterol, triglycerides, HDL), age, and SFAs (all determined) and some of PUFA (dihomogamma-linolenic acid-C20:3, and eicosopentaenoic acid-C20:5) between study populations (p < 0.05). In control group, a strong negative association between serum levels of total bilirubin and myristic acid, C14:0 and arachidic acid (C20:0) (p < 0.05) and positive association of total bilirubin with stearic acid (C18:0), and dihomo­gamma­linolenic acid (C20:3) was demonstrated (p < 0.05). Interestingly, a strong negative association between serum levels of total bilirubin and myristic acid (C14:0), stearic acid (C18:0), and linoleic acid (C18:2) (p < 0.001) was demonstrated in diabetic patients. It appears that elevated concentrations of total bilirubin and FFA of different chain length and saturation are associated with the development of T2D and could be used as potential T2D biomarkers and therapeutic targets.