Serum Levels of Novel Biochemical Marker (Irisin) in Relation to the Duration of Type 2 Diabetes & in Cases of Type 2 diabetes with Coronary Artery Disease in Iraqi Patients Aged (40- 60 year)

Background: Type 2 diabetes mellitus (T2DM) is a metabolic syndrome that affects a large proportion of the population, if not well controlled; this will lead to serious metabolic problems, including atherosclerosis, predominantly coronary artery disease (CAD). Irisin is a peptide hormone, secreted mainly by the heart and skeletal muscle. It has a role in converting white adipose tissue to brown adipose tissue. It is one of the novel biochemical markers that link diabetes with CAD. Objective: To explore the relationship between serum Irisin level and duration of diabetes, in cases of presence and absence of CAD, As well as the possibility of using it as a marker for the assessment of the severity of the disease. Method: One hundred sixty-one volunteers aged [(40-60 year), body mass index (20- 25Kg/m2)], with normal blood pressure. They divided into six groups, that distributed as [(I_a = control (negative catheterization without DM), I_b = control (apparently healthy), II_a = DM (with negative catheterization) II_b = DM (diagnosed by history and clinical examination), III_a = CAD (without DM, positive catheterization), III_b = CAD + DM (positive catheterization)]. The diabetic groups with and without CAD had been divided depending on the duration of the diabetic onset into three periods (<5, 5-10, and > 10 years). The parameters that measured were FPG, HbA1c and fasting serum (Irisin, lipid profile). Results: The present findings showed the Means (± SD) value of Irisin levels was a significant decrease in (II_a, II_b, III_a, III_b ) groups as compared with control groups (I_a, I_b). In addition, there is an inverse relationship between serum Irisin and the duration of DM in the total DM groups (II_a +II_b) and the CAD + DM group (III_b). Moreover, higher statistical decrease in mean serum level of Irisin with duration of DM was found in CAD + DM group as compared with the total DM group. Also, there was a significant decrease in mean serum level of HDL-C for (II_a, II_b, III_a, III_b) groups than in (I_a, I_b) groups. Besides, there was a significant decrease in the mean of serum HDL level in CAD groups (III_a, III_b) than in DM groups (II_a, II_b). While the means of FPG level, HbA1c, serum cholesterol level, were significantly elevated in groups (II_a, II_b, III_b) as compared with (I_a, I_b) groups. Also, there was a significant increase in the mean serum levels of triglyceride, VLDL-C and LDL-C for (II_a, II_b, III_a, III_b ) groups than in the control groups. Conclusion: Irisin was lower among patients with long-standing diabetes (with or without CAD) as compared to those with short duration of T2DM that can be included as a marker for assessment the severity of diabetes and prediction of CAD.