Platelet aggregation is not enhanced in patients with prediabetes.

Prediabetes [impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG)] is a major risk factor for T2DM as well as for cardiovascular disease and mortality. In the present study, the platelet aggregation and fibrinogen levels were investigated in prediabetic subjects who had no confounding factors such as hypertension, obesity or dyslipidemia. Thirty-nine subjects with prediabetes (24 IFG and 15 IGT) and age, sex and BMI matched 36 healthy controls were enrolled. Platelet aggregation, fibrinogen and hsCRP levels, HOMA-IR and HOMA-beta indexes were determined. Platelet aggregation induced by collagen, epinephrine or ADP was not different (p=0.93, p=0.90 and p=0.29, respectively) between two groups, whereas fibrinogen levels were significantly higher (p=0.006) in the prediabetics when compared to controls. hsCRP levels, HOMA-IR and HOMA-beta indexes in the two groups were not different. The power of the study was calculated according to the results and established as 0.97 for collagen, 0.95 for epinephrine and 0.83 for ADP. Despite the high plasma fibrinogen levels, the platelet aggregation in prediabetics was not different when compared to healthy controls. These data suggest that platelet aggregation may not be involved in the mechanism of prothrombotic state in prediabetic state.

Adiponectin and insulin resistance in young and healthy smokers.

Smoking is closely associated with insulin resistance, though the mechanism is not clear. Adiponectin, a novel anti-atherosclerotic and anti-inflammatory adipose tissue product, which is closely associated with insulin resistance, was reported to be low in smokers with cofactors for atherosclerosis. However, the effects of smoking on circulating adiponectin levels in otherwise healthy people are unknown. In this study, a case control design was implemented to search for the effect of smoking on plasma adiponectin and insulin sensitivities in healthy people. Sixty-four healthy male smokers, with no family history of hypertension and diabetes mellitus were compared with appropriate 36 age and body mass index matched controls. Both the patients and controls were the soldiers of a troop with regular daily physical activity. Plasma adiponectin, high sensitive C-reactive protein (hsCRP), insulin and lipid levels, and insulin sensitivity as assessed by homeostasis model assessment index (HOMA) of the smokers were measured and compared with those of the controls. The plasma adiponectin, hsCRP, insulin levels and HOMA indexes of the two groups were similar. These parameters were not affected by the amount of cigarettes per day. HDL-cholesterol levels were lower (p = 0.01) and systolic blood pressures were higher (p = 0.02) in the smokers. These results indicate that smoking may not affect plasma adiponectin and insulin levels in young and healthy men with high exercise capacity.

The effect of fluvastatin on plasma adiponectin levels in dyslipidaemia.

OBJECTIVE: There is controversy about the effects of statins on insulin resistance and plasma adiponectin. The aim of this study was to investigate the effects of fluvastatin treatment on these parameters in a group of dyslipidaemic patients who had no confounding factors for insulin resistance or alterations in plasma adiponectin. DESIGN AND PATIENTS: Forty-nine patients [27 males, 22 females; mean age 47.2 +/- 10.3 years; body mass index (BMI) 29.64 +/- 3.2 kg/m2] with dyslipidaemia and 20 controls (six males, 14 females; mean age 45.3 +/- 9.31 years; BMI 30.07 +/- 4.04 kg/m2) were enrolled. All patients were treated initially with therapeutic lifestyle changes (TLC) for 6 weeks. Six out of 49 subjects were excluded from the study. Then, 24 out of 43 patients with high blood cholesterol despite TLC were allocated to fluvastatin 80 mg daily plus TLC, and the remaining 19 patients with normal cholesterol were subjected to TLC alone for additional 12 weeks. MEASUREMENTS: Plasma adiponectin, immunoreactive insulin levels, BMI, waist circumference, blood pressure, lipids, and glucose were determined. The insulin sensitivity index was quantified using the homeostasis model assessment (HOMA). RESULTS: TLC caused significant improvement in plasma insulin (P = 0.02) and elevation in plasma adiponectin (P = 0.02). Fluvastatin treatment decreased total cholesterol and low density lipoprotein (LDL)-cholesterol significantly (P = 0.01 and P = 0.02, respectively). No significant effect of fluvastatin was observed on plasma insulin or adiponectin or on the HOMA index. CONCLUSIONS: Fluvastatin does not improve plasma adiponectin levels and insulin sensitivity, despite its beneficial effects on lipid levels. Our data, however, were limited by the fact that a more accurate method of assessing insulin sensitivity, the euglycaemic-hyperinsulinaemic glucose clamp technique, was not used.

Soluble CD40 ligand levels in otherwise healthy subjects with impaired fasting glucose.

Unlike diabetes mellitus and impaired glucose tolerance, it is not clear whether the subjects with impaired fasting glucose (IFG) are at increased risk of atherosclerosis and cardiovascular diseases. The CD40-CD40 ligand interaction is involved in the mechanism of atherosclerosis. We investigated whether soluble CD40L (sCD40L) as well as high sensitive C-reactive protein (hsCRP) levels are increased in subjects with IFG having no confounding factors for inflammation or atherosclerosis. Twenty four IFG subjects with no additional disorders and 40 appropriate healthy controls were studied. sCD40L and hsCRP levels in the IFG and control groups were similar. Blood pressures, total and LDL-cholesterol, and triglyceride levels were also similar, whereas HDL-cholesterol was lower and HOMA-IR indexes were higher in the IFG group. Though the sample size was small, the present data show that sCD40L seems not to alter in subjects with IFG suggesting that it might not be an independent risk factor for atherosclerosis.