Serum leptin level as a cardiovascular risk factor in type 2 diabetic patients

Abstract

Type 2 diabetes mellitus ( T2DM ) is a metabolic disease that is associated with an increased risk for atherosclerosis. Leptin is a hormone – like cytokine that is derived mainly from adipose tissue and has multiple functions. Recently, many vascular and atherogenic effects for leptin have been demonstrated. The aim was to study serum leptin level and its relationship with some cardiovascular risk factors in T2DM patients. Forty diabetic males with ischemic heart disease (IHD group), aged ≥ 40 years old, were compared with 40 diabetic males of similar ages who had no clinical history of IHD (DM group). Each main study group was divided into two subgroups according to the presence or absence of metabolic syndrome. The IHD group was also subdivided according to their clinical endpoints into stable angina pectoris (angina group), significant coronary artery disease on angiography (angiography group ) and myocardial infarction (MI group ). In addition to anthropometric measurements; serum lipid profile, thiobarbituric acid -reactive substances (TBARS) and leptin levels as well as plasma fibrinogen level were quantified .
A highly significant increase of mean serum leptin level was observed in IHD group iin comparriison wiitth tthatt off DM grroup (11.56  10.27 vs. 7.39  3.54 ng /3ml, p<0.01). IIHD pattiientts showed a hiighlly siigniiffiicantt iincrrease iin serrum llevell off
TBARS iin comparriison wiitth tthatt off DM grroup ((9.00  3.61vs. 6.65  2.41 mol (MDA)/L, P<0.001). The mean plasma level of fibrinogen is significantly higher in IHD group than in DM group (3.30  0.65 vs. 2.99  0.63 g/dl, p < 0.05). Serum leptin level was significantly higher in (angiography group) but not in (angina group) while the level was even lower in (MI group) when compared with that of DM group. A significant increase of mean serum leptin level was observed in IHD subgroup with non-metabolic syndrome in comparison with the D.M subgroup with non-metabolic syndrome (13.06  11.01 vs. 7.06  3.08 ng/ml, P<0.05). In IHD group, serum leptin level showed a positive correlation with BMI ,W/h ratio, serum TBARS, and plasma fibrinogen. In DM group, serum leptin level showed a positive correlation with BMI, W/h ratio, and plasma fibrinogen, while insignificantly correlated with TBARS. In conclusion, T2DM patients with IHD have an elevated serum leptin level that is associated with oxidative stress, inflammation and active or worsening ischemic heart disease independent of metabolic syndrome. Thus, serum leptin level could be an additional factor to assess cardiovascular risk