Leptin, soluble leptin receptor, adiponectin and resistin in relation to OGTT in overweight/obese postmenopausal women.

OBJECTIVE: In obese postmenopausal women with normal glucose metabolism (NGT) and impaired glucose tolerance (IGT) we assessed serum leptin, adiponectin, resistin, soluble leptin receptor (sOB-R) during oral glucose tolerance test (OGTT) in order to investigate their response to acute changes in glucose and insulin in the abnormal glucose metabolism, as it is early detected by IGT. METHODS: Thirty in total, overweight/obese postmenopausal women, were included in the study: 15 with NGT and 15 with IGT as it was diagnosed by OGTT. Serum glucose and insulin levels were measured at 30 min intervals, leptin, sOB-R, adiponectin and resistin at 60 min intervals during the 120 min OGTT. RESULTS: In fasting state, leptin, adiponectin, resistin and sOB-R levels did not differ between the two groups. In women with NGT, leptin was positively correlated with BMI, insulin and HOMA, and negatively correlated with QUICKI and with sOB-R; adiponectin was negatively correlated with insulin and HOMA and positively correlated with QUICKI. In women with IGT, resistin was positively correlated with BMI and waist circumference. In both groups, sOB-R was negatively correlated with insulin. During OGTT, in both groups, leptin concentration increased significantly and fasting glucose predicts significantly serum leptin change; there was no change in adiponectin, resistin and sOB-R concentrations. CONCLUSION: In overweight/obese postmenopausal women fat distribution does not affect leptin and adiponectin production. Abnormal glucose metabolism is not accompanied by disturbance in adipokines production. Leptin secretion is acutely regulated by glucose levels in insulin presence.

Serum oxidizability, total antioxidant status and albumin serum levels in patients with aneurysmal or arterial occlusive disease.

OBJECTIVES: Oxidative stress is involved in the pathophysiology of atherosclerosis. The aim of the present study was to estimate the extent of oxidative stress in patients with aneurysmal and arterial occlusive disease (AAOD) by analyzing the magnitude of serum oxidizability, total antioxidant status and serum antioxidants and to evaluate their potential clinical significance. DESIGN AND METHODS: The study was conducted on 47 patients with AAOD and 49 healthy individuals. Oxidative stress was assessed by: a) copper-induced lipid oxidation described in terms of "lag-time" (t(LAG)) and "maximal rate of accumulation of absorbing products" (RA) and b) the measurement of serum total antioxidant status (TAS) and hydrophilic serum antioxidants (albumin, uric acid, transferrin, bilirubin). LDL-cholesterol and HDL-cholesterol were also estimated. RESULTS: A decrease of t(LAG) and albumin levels in patients as compared to controls was observed. t(LAG) was negatively correlated with RA in both patients and controls. RA and LDL-cholesterol did not differ between the two groups. HDL-cholesterol was decreased in patients in comparison to controls. There is statistically significant evidence that low albumin serum levels are associated with increased risk of AAOD. CONCLUSIONS: The results support the involvement of oxidative stress in AAOD. Significant alterations in serum oxidizability were found in patients with AAOD and low albumin serum levels were correlated with the disease. Clinical evaluation of both findings needs further investigation.

Oxidized LDL, serum oxidizability and serum lipid levels in patients with breast or ovarian cancer.

OBJECTIVES: The aim of this study was to evaluate the extent of oxidative stress in patients with breast or ovarian cancer by analyzing the magnitude of serum oxidizability and the involvement of oxidized low-density lipoproteins (oxLDL) in the disease. DESIGN AND METHODS: The study was conducted on 32 patients diagnosed with breast or ovarian cancer but who had not undergone any kind of treatment and 30 healthy individuals of similar age. The evaluation of oxidative stress was assessed by: (a) the ex-vivo susceptibility of serum lipids to oxidation and (b) the detection of oxLDL and anti-oxLDL autoantibodies. Total cholesterol, LDL-cholesterol and HDL-cholesterol were co-estimated. RESULTS: The results indicated that the levels of oxLDL were increased among both breast and ovarian cancer patients as compared to the control subjects. Additionally in patients with breast cancer, serum total cholesterol, LDL-cholesterol, anti-oxLDL antibodies and the maximal rate of diene formation (RA), the index of oxidizable components load, were increased in comparison to controls. There is statistically significant evidence that serum oxLDL levels are associated with increased risk of breast and ovarian cancer. CONCLUSIONS: The findings exhibit a correlation between oxLDL and malignancy, supporting the contribution of oxidative stress to carcinogenesis and the possible involvement of oxLDL in the process of malignancy. The clinical evaluation of the oxLDL measurement is under investigation.

Circulating oxidized low density lipoprotein, autoantibodies against them and homocysteine serum levels in diagnosis and estimation of severity of coronary artery disease.

The oxidative hypothesis of atherosclerosis proposes that oxidative modification of low density lipoprotein (LDL) plays a critical role in atherogenesis. The evaluation of LDL oxidation in vivo is therefore very important. However, data concerning the evaluation of the above biochemical marker is very limited in clinical practice. This study was conducted to test the hypothesis that plasma levels of ox-LDL reflect atherosclerosis and determine the clinical significance in the measurement of circulating ox-LDL and autoantibodies against them as well as their correlation with homocysteine and lipid parameters in the diagnosis and severity of coronary heart disease. A total of 273 individuals were examined: 41 suffering from unstable angina pectoris (UAP), 62 from stable angina pectoris (SAP) and 170 healthy control subjects. We used a sensitive method for detecting ox-LDL that is based on a direct sandwich technique (ELISA) in which two monoclonal antibodies are directed against separate antigenic determinants on the oxidized apolipoprotein-B molecule along with another enzyme immunoassay designed to determine human antibodies to oxidized LDL (anti-oxLDL) directly in serum. Total homocysteine (HCY) was evaluated by means of a fully automated fluorescence polarization immunoassay. Patients with UAP exhibited marked elevations in oxLDL levels as compared to patients with SAP (161.2 +/- 28.4 vs. 119.2 +/- 26.6, p < 0.001) and the control subjects (67 +/- 18.8, p < 0.001). The difference in oxLDL levels between patients with SAP and the control group was also statistically significant. Similarly, patients with UAP showed marked elevations in anti-oxLDL antibodies compared to both patients with SAP (602.2 +/- 62.2 vs. 510.8 +/- 50.3,p < 0.001) and control subjects (368 +/- 79.6, p < 0.001). The difference in anti-oxLDL levels between patients with SAP and the controls was also statistically significant. OxLDL levels were not correlated with age in any of the groups studied. Triglycerides, LDL-cholesterol and total cholesterol were elevated in patients with UAP as opposed to patients with SAP and the control subjects, while HDL levels were elevated in the control subjects when compared to patients with SAP and UAP. Homocysteine levels were elevated in patients suffering from UAP and SAP when compared to healthy subjects. Patients with UAP or SAP did not differ on homocysteine levels. Our findings demonstrate the presence of oxLDL in vivo, its strong association with coronary artery disease as well as with the severity of the clinical presentation.

Evidence of reduced plasma HDL subfractions in patients with cutaneous discoid lupus erythematosus.

OBJECTIVES: The aim of the present study was to evaluate the dyslipidemic profile of patients with Cutaneous Discoid Lupus Erythematosus (DLE) with particular emphasis on the levels of High Density Lipoprotein (HDL) Cholesterol and its subfractions, HDL2 and HDL3. DESIGN AND METHOD: The study involved characterization of the lipid profile of 30 patients with diagnosed DLE (11 male and 19 female) and 34 age- and BMI-matched healthy individuals. RESULTS: Patients with DLE presented increased serum cholesterol, triglycerides and LDL-Cholesterol levels (P < 0.001, respectively) compared to the control group, while the levels of HDL-Cholesterol (P < 0.001), as well as its subfractions, HDL2 (P < 0.001) and HDL3 (P < 0.02) were markedly decreased. In addition, the ratio of CHOL/HDL was increased in patients with DLE (P < 0.001), whereas a reduction was observed in the ratio of HDL2/HDL3 (P < 0.001) in the same group. CONCLUSIONS: Our findings suggest that patients with cutaneous discoid lupus erythematosus have an increased risk of atherosclerosis due to the marked dyslipidemia associated with the disease. The reduced levels of HDL subfractions, HDL2 and HDL3, are believed to contribute to the dyslipidemic profile and further provide an important target for therapeutic intervention.