The risk of atherosclerosis in patients with impaired glucose tolerance.

OBJECTIVES: Glucose metabolism disorders usually coexist with dyslipidemia and coagulation/fibrinolysis disturbances. Increase of insulin resistance followed by hyperinsulinemia leads to enhanced protein synthesis, including production of apolipoproteins. As a result, the structure of Low Density Lipoprotein (LDL) becomes small and dense. This augments lipid infiltration into the arterial wall. Following this process monocyte adhesion to endothelium initiates atherosclerotic injury. One of the markers of this inflammatory reaction is Monocyte Chemoattractant Peptide-1 (MCP-1). A lot of inflammatory mediators affect both oxidative modification of LDL and coagulation processes being responsible for anti-fibrinolytic predominance. Plasminogen Activator Inhibitor-1 (PAI-1) is a marker of this state. Therefore the aim of this study is to evaluate the marker of the oxidation processes (oxLDL) as well as prothrombotic (PAI-1) and inflammatory state (MCP-1) markers in patients with Impaired Glucose Tolerance (IGT). METHODS: The study was carried out on 16 subjects: 10 with biochemically confirmed IGT and 6 age-matched healthy persons without such disorders. Following tests were performed: OGTT, HbA(1c) level as well as TCh, HDL, LDL and TG. Plasma concentrations of oxLDL, PAI-1 and MCP-1 were measured using ELISA method. RESULTS: In patients with Impaired Glucose Tolerance plasma levels of oxLDL were significantly higher compared to control group (67.6 +/- 0.9 U/l vs. 57.8 +/- 4.0 U/l; p < 0.01) in spite of LDL levels, which did not reveal such difference. MCP-1 plasma concentration compared to control group occurred to be significantly increased in experimental group as well (156.4 +/- 9.2 ng/ml vs. 125.4 +/- 1.9 ng/ml; p < 0.05). PAI-1 level revealed most significant difference (84.0 +/- 1.8 ng/ml vs. 43.7 +/- 2.7 ng/ml; p < 0.0001). CONCLUSIONS: It is concluded that patients with Impaired Glucose Tolerance should be considered as a group in which atherogenic modification of lipoproteins occurred. Also plasma inflammatory as well as prothrombotic markers concentration was elevated.

Effects of fibrates on plasma prothrombotic activity in patients with type IIb dyslipidemia.

OBJECTIVE: Increased levels of fibrinogen and plasminogen activator inhibitor 1 (PAI-1) are associated with an increased risk of ischemic coronary disease and its complications. Since atherogenic dyslipidemias are well-known risk factors for coronary heart disease, this study aimed to determine whether Type IIb dyslipidemia, one of the most atherogenic dyslipidemias, is accompanied by increased PAI-1 and fibrinogen synthesis. The additional aim of this study was to evaluate the effect of micronized fibrates on the levels of PAI-1 and fibrinogen in patients with Type IIb dyslipidemia. SUBJECTS: Thirty patients with Type IIb dyslipidemia and 12 age-matched control subjects were studied. Fourteen patients were treated with fenofibrate and 16 were treated with ciprofibrate for 1 month. METHODS: Plasma PAI-1 levels were measured by the ELISA method with Diagnostica Stago kit. The level of fibrinogen was measured by the Clauss method. RESULTS: PAI-1 levels in dyslipidemic patients before treatment differed significantly in both the fenofibrate and ciprofibrate treatment groups (101.18 +/- 36.47 ng/ml, 87.64 +/- 32.06 ng/ml, respectively) from those in the control group (32.32 +/- 7.39 ng/ml, p < 0.001). Compared with the control subjects (2.91 +/- 0.35 g/l), fibrinogen levels before treatment were higher in patients with dyslipidemia treated with ciprofibrate (3.42 +/- 0.59 g/l, NS) and fenofibrate (3.65 +/- 1.10 g/l, p < 0.05). One-month ciprofibrate treatment resulted in an insignificant decrease in PAI-1 levels (76.28 21.60 ng/ml, NS) and in a significant decrease in fibrinogen levels (2.73 +/- 0.40 g/l, p < 0.01). After one-month fenofibrate treatment PAI-1 levels (81.22 +/- 25.01 ng/ml, p < 0.01) and fibrinogen levels (2.95 0.72 g/l, p < 0.01) decreased significantly. CONCLUSION: Type IIb dyslipidemic patients have increased levels of PAI-1 and fibrinogen. Micronized fibrates decreased not only lipid levels but also the levels of fibrinogen and PAI-1 in these patients.