Adipokines as atherothrombotic risk factors in obese subjects: Associations with haemostatic markers and common carotid wall thickness.

BACKGROUND AND AIMS: Some crucial associations between obesity-related altered adipokine levels and the main factors of atherosclerotic, atherothrombotic processes are not fully known. We analysed the relationships of classic adipokines, namely leptin, resistin, adiponectin, tumour necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) with the markers of platelet activation, including mean platelet volume (MPV), platelet surface/soluble P-selectin, platelet-derived microparticles (PMPs), the parameters of coagulation abnormalities and common carotid intima-media thickness (IMT) in obese patients with or without atherosclerotic comorbidities in comparison to age- and sex-matched controls. METHODS AND RESULTS: We enrolled 154 obese individuals, including 98 suffering from atherosclerotic concomitant conditions, 56 free of atherosclerotic comorbidities and 62 healthy controls. Plasma levels of leptin, resistin, adiponectin, TNF-α, IL-6, soluble P-selectin, and plasminogen activator inhibitor-1 antigen (PAI-1 ag) were analysed by ELISA. Platelet surface P-selectin and PMPs were measured by flow cytometry. IMT was detected by ultrasonography. Adipokines were closely associated with markers of platelet hyperactivity, hypercoagulability, hypofibrinolysis and IMT. Significant independent associations were found between leptin and platelet count (p < 0.0001), MPV (p = 0.019), PMPs (p < 0.0001), fibrinogen (p = 0.001), factor VIII (FVIII) activity (p = 0.035); adiponectin and PAI-1 ag (p = 0.035); resistin and soluble P-selectin (p = 0.002); TNF-α and PAI-1 ag (p < 0.0001); and IL-6 and fibrinogen (p = 0.011). Finally, leptin (p = 0.0005), adiponectin (p = 0.019), IL-6 (p = 0.001), MPV (p = 0.0003), PMP (p = 0.008), and FVIII activity (p = 0.043) were independent predictors of IMT. CONCLUSION: Overall, we suggest that in obese subjects altered adipokine levels play a key role in common carotid atherosclerosis both directly and through haemostatic parameters.

Effects of fluvastatin and coenzyme Q10 on skeletal muscle in normo- and hypercholesterolaemic rats.

Myalgia and muscle weakness may appreciably contribute to the poor adherence to statin therapy. Although the pathomechanism of statin-induced myopathy is not completely understood, changes in calcium homeostasis and reduced coenzyme Q10 levels are hypothesized to play important roles. In our experiments, fluvastatin and/or coenzyme Q10 was administered chronically to normocholesterolaemic or hypercholaestherolaemic rats, and the modifications of the calcium homeostasis and the strength of their muscles were investigated. While hypercholesterolaemia did not change the frequency of sparks, fluvastatin increased it on muscles both from normocholesterolaemic and from hypercholesterolaemic rats. This effect, however, was not mediated by a chronic modification of the ryanodine receptor as shown by the unchanged ryanodine binding in the latter group. While coenzyme Q10 supplementation significantly reduced the frequency of the spontaneous calcium release events, it did not affect their amplitude and spatial spread in muscles from fluvastatin-treated rats. This indicates that coenzyme Q10 supplementation prevented the spark frequency increasing effect of fluvastatin without having a major effect on the amount of calcium released during individual sparks. In conclusion, we have found that fluvastatin, independently of the cholesterol level in the blood, consistently and specifically increased the frequency of calcium sparks in skeletal muscle cells, an effect which could be prevented by the addition of coenzyme Q10 to the diet. These results support theories favouring the role of calcium handling in the pathophysiology of statin-induced myopathy and provide a possible pathway for the protective effect of coenzyme Q10 in statin treated patients symptomatic of this condition.

Two dose-ranging studies with PF-04937319, a systemic partial activator of glucokinase, as add-on therapy to metformin in adults with type 2 diabetes.

AIM: To assess the efficacy and safety of a range of doses of a systemic, partial, glucokinase activator, PF-04937319, as add-on therapy to metformin, in patients with type 2 diabetes mellitus (T2DM). METHODS: Patients were randomized to once-daily PF-04937319 doses of 10, 50, 100 mg, or matching placebo (Study B1621002); or PF-04937319 doses of 3, 20, 50, 100 mg, or matching placebo (Study B1621007). Titrated glimepiride (Study B1621002) or sitagliptin (Study B1621007) were included in a double-dummy manner. The primary measure was change from baseline in glycated haemoglobin (HbA1c) at week 12. Key secondary measures included other glycaemic variables and safety and tolerability. RESULTS: In the 639 patients randomized, the minimally efficacious PF-04937319 dose was identified as 50 mg once daily. At the highest PF-04937319 dose tested (100 mg), on average, a clinically significant reduction in HbA1c [-4.94 or -5.11 mmol/mol (-0.45 or -0.47%), placebo-adjusted], which was similar to that achieved with sitagliptin [-4.69 mmol/mol (-0.43%)] but lower than that achieved with titrated glimepiride [-9.07 mmol/mol (-0.83%)], was observed. At this dose, the effect on fasting plasma glucose was not consistent between the two studies (Study B1621002 vs Study B1621007: placebo-adjusted mean change of -0.83 vs +0.50 mmol/l). PF-04937319 was well tolerated at doses up to 100 mg. Hypoglycaemia was reported in 2.5% of patients (on placebo), 5.1% of patients (on PF-04937319 100 mg), 1.8% of patients (on sitagliptin) and 34.4% of patients (on titrated glimepiride). CONCLUSIONS: In patients on metformin monotherapy, the addition of a 100-mg dose of PF-04937319 improved glycaemic control and was well tolerated.

Effect of thyroid hormone status and concomitant medication on statin induced adverse effects in hyperlipidemic patients.

Statins are effective treatment for the prevention of cardiovascular diseases and used extensively worldwide. However, adverse effects induced by statins are the major barrier of maximalizing cardiovascular risk reduction. Hypothyroidism and administration of drugs metabolized on the same cytochrome P450 (CYPP450) pathways where statin biotransformation occurs represent a significant risk factor for statin induced adverse effects including myopathy. Simvastatin, atorvastatin and lovastatin are metabolized by CYP3A4, fluvastatin by CYP2C9, while rosuvastatin by CYP2C9 and 2C19. We investigated the levels of the free thyroid hormones and CYP metabolism of concomitant medication in 101 hyperlipidemic patients (age 61.3 +/- 9.9 ys) with statin induced adverse effects including myopathy (56 cases; 55.4%), hepatopathy (39 cases; 38.6%) and gastrointestinal adverse effects (24 cases; 23.8%). Abnormal thyroid hormone levels were found in 5 patients (4.95%); clinical hypothyroidism in 2 and hyperthyroidism in 3 cases. 11 patients had a positive history for hypothyroidism (10.9%). Myopathy occured in one patient with hypothyroidism and two patients with hyperthyroidism. There were no significant differences in the TSH, fT4 and fT3 levels between patients with statin induced myopathy and patients with other types of adverse effects. 78 patients (77.2%) were administered drugs metabolized by CYP isoforms also used by statins (3A4: 66 cases (65.3%); 2C9: 67 cases (66.3%); 2C19: 54 cases (53.5%)). Patients with myopathy took significantly more drugs metabolized by CYP3A4 compared to patients with other types of adverse effects (p < 0.05). More myopathy cases were found in patients on simvastatin treatment (52% vs. 38%, ns.), while significantly less patients with myopathy were on fluvastatin treatment (13% vs. 33%, p < 0.05) compared to patients with other types of statin induced adverse effects. Both abnormal thyroid hormone status and administration of drugs metabolized by CYP3A4, 2C9 and 2C19 are common in our patients with statin induced adverse effects. Normalizing the thyroid hormone status and optimizing of the concomitant medication may reduce the risk of statin induced adverse effects.

The c.-133A > G polymorphism in NPC1L1 gene influences the efficacy of ezetimibe monotherapy on apolipoprotein A1 in hyperlipidemic patients.

Niemann-Pick C1-like 1 protein (NPC1L1) plays a critical role in intestinal cholesterol absorption. Previous studies found that the NPC1L1 c.-133A > G SNP, but not other NPC1L1 SNPs, was associated with response to statin treatment and statin-ezetimibe combinations. To date effect of NPC1L1 c.-133A > G SNP on ezetimibe monotherapy has not been studied. Our objective was to examine whether SNP c.-133A > G at the NPC1L1 gene has effects on lipid levels and on the efficacy of 3, 6 and 12 months of 10 mg daily ezetimibe monotherapy in hyperlipidemic patients with statin induced adverse effects. One hundred and one type IIa and IIb hyperlipidemic patients (72 females, 29 males; age: 61.23 +/- 9.87 ys; BMI: 28.18 +/- 4.29 kg/m2) were enrolled. The genotype frequencies were conformed to Hardy-Weinberg equilibrium. We could not find significant differences in initial lipid levels between AA and AG + GG patients. While plasma levels of apolipoprotein A1 (ApoA1) did not significantly decrease after ezetimibe treatment (1.96; 3.39 and 2.74%) in AA patients, a significant elevation in ApoA1 levels has been found after treatment in AG + GG patients (9.15; 8.54 and 13.58%). The effect of NPC1L1 c.-133A > G on the ApoA1 levels was found significant (p < 0.05). Efficacy of treatment with ezetimibe on other plasma lipid parameters after 3, 6 or 12 months did not differ significantly. NPC1L1-133A > G SNP influences the ApoA1 response to ezetimibe monotherapy, therefore, may alter the effect of ezetimibe on the structure and function of the high-density lipoprotein particles.

Effect of drugs used in different type of myocardial infarction (STEMI or (NTEMI) on mortality.

We examined 416 patients with acute myocardial infarction. 249 patients had STEMI and 167 NSTEMI. 227 were men and 189 women. 142 men had STEMI and 85 men had NSTEMI. 107 women were diagnosed with STEMI and 82 with NSTEMI. 22.5% of patient with STEMI and 20.2% of patients with NSTEMI died (p = 0.58). We compared the effect of anticoagulant treatment, clopidogrel, salicylate, nitrate, beta-blocker, angiotensin-converting enzyme inhibitor, statin and trimetazidine therapy on mortality in function of the type of myocardial infarction. There were no differences between mortality of patients with STEMI and NSTEMI with respect of use of heparine, salicylate, nitrate, beta-blocker, ACE inhibitor, statin and trimetazidine. While examining the effect of clopidogrel, we observed a significantly lower mortality rate in patients with NSTEMI compared to the STEMI group (p = 0.005). These differences are due to the known variability in clopidogrel absorption and metabolism, which could be influenced by the type of myocardial infarction.

A comparative study on dyslipidaemia inducing diets in various rat strains.

In our experiments we compared the serum lipoprotein lipid composition of Fischer 344 (F344) and Long-Evans (LE) inbred rats as well as of their hybrid FLF(1) from both sexes after feeding them for 2, 4 and 8 weeks with different diets. The following diets were used: 1) standard diet marked as CRLT/N; 2) diet reach in butter marked as BR; 3) diet containing cholesterol, sodium cholate and methylthiouracil marked as CR; 4) diet marked as BRC, which is the Hartroft-Sós diet modified by our research group consisting of the diets BR and CR. The latter diet was the most effective, because within two weeks the level of serum total cholesterol, LDL-cholesterol, HDL-cholesterol and triglyceride in the F344 female rats increased 8, 30, 4 and 8 times, respectively. The male rats of the Long-Evans strain showed moderately increased values while the FLF(1) female hybrids derived from the hybridization of LE males and F344 females had values closer to those of the mother strain. Despite the fact that during this time the LDL/HDL ratio increased from 0.06 to 2.97 and the PON-1 activity decreased to one-third, a significant lipid deposition could not be shown in the wall of the abdominal aorta even two months later. Our experimental model is suitable for the chemoprevention of dyslipidaemia or rapid testing of molecules chosen for its treatment.

Relationship between serum paraoxonase and homocysteine thiolactonase activity, adipokines, and asymmetric dimethyl arginine concentrations in renal transplant patients.

Paraoxonase lactonase activity protects against homocysteinylation; therefore, it can be a potential contributing factor to prevent atherosclerosis. We aimed to determine paraoxonase and HTLase activities and to clarify the relationship between HTLase activity and some cardiovascular risk factors, such as homocysteine, cystatin C asymmetric dimethylarginine (ADMA), and adipokines both in hemo dialyzed and transplanted patients. Among 114 hemodialyzed, 80 transplanted and 64 healthy control subjects, we investigated body mass index (BMI) as well as fasting serum contents of urea, uric acid, creatinine, cystatin C, homocysteine, glucose, lipids, total protein and albumin. Serum paraoxonase (PON 1) and HTLase activities were measured spectrophotometrically. ADMA, ADPN adiponectin, leptin (LEP) levels was determined with a sandwich enzyme-linked immunosorbent assay method. Dyslipidemic patients showed hypercholesterolemia, and high low-density lipoprotein (LDL); parallel with improved renal function, they displayed decreased cystatin C and homocysteine levels (P < .001). There was a significant negative correlation between PON 1 activity and cystatin C and homocysteine concentrations (P < .05). Obese patients revealed significantly higher LDL (P < .05) and leptin concentrations (P < .01). There was a significant positive correlation between PON 1 activity and adiponectin levels (P = .0276). Both dialyzed and transplanted patients displayed significantly lower HTLase activities compared to the control group (P < .001), particularly lower HTLase and PON 1 activities in dialyzed subjects compared with the transplanted group (P < .05). HTLase activity showed significant negative correlations with ADMA levels among the whole study population (P < .001), whereas positive associations were noted between PON 1 and HTLase activities (P < .001). HTLase activity may be a new predictor of cardiovascular risk in renal failure although it is modulated by other risk factors.

Evaluation of the metabolic changes during hemodialysis by signal averaged ECG.

Cardiovascular diseases are frequent complications of end-stage kidney disease. The aim of the present study was to prove the arrhythmogenic effect of dialysis using signal averaged ECG. The ECG changes and laboratory parameters (sodium, potassium, urea and creatinine levels) were detected during hemodialysis treatment in 26 patients suffering from end-stage kidney disease. The tests and the ECG were performed four times, before (0. minute), during (at 15 and 90 min), and eventually after dialysis (at 240 min). The duration of the QRS complex, high-frequency low-amplitude signals (HFLA), and root-mean-square voltage of the terminal 40 ms of the filtered QRS (RMS) were determined. We considered test results to be positive when two of the three tested parameters were outside the normal range: QRS > 120 ms, RMS < 20 uV, HFLA > 39 ms. Signal averaged ECG was positive in two cases (8%) before and after the dialysis. The duration of the QRS-complex increased significantly during the dialysis (predialysis: 109 +/- 7.6 ms, postdialysis: 116 +/- 8.0 ms, p < 0.0001). Serum urea nitrogen (predialysis: 26.2 +/- 5.4, postdialysis: 11.4 +/- 3.3 mmol/l, p <0.0001) and serum creatinine levels (predialysis: 931 +/- 212, postdialysis: 434 +/- 120 micromol/I, p < 0.0001) decreased significantly during the treatment. Significant and continuous decrease in the potassium levels were detected (predialysis: 5.30 +/- 0.72, postdialysis: 3.91 +/- 0.42 mmol/I, p < 0.0001) during the dialysis. Serum sodium levels (predialysis: 139 +/- 2.7, postdialysis: 141.4 +/- 2.2 mmol/I) had not changed during the dialysis. A significant negative correlation was found between decreasing potassium levels and increasing QRS duration (r = - 0.48, p = 0.01). Our results support our primer assumption that the metabolic changes during dialysis treatment can lead to considerable risk of cardiac arrhythmias.

CCR7-expressing B16 melanoma cells downregulate interferon-γ-mediated inflammation and increase lymphangiogenesis in the tumor microenvironment.

The expression of the CC chemokine receptor-7 (CCR7) by cancers, including melanoma, augments lymph node (LN) metastasis, but little is known about its role in lymphangiogenesis and anti-tumor immunity. We injected control B16 murine melanoma cells (pLNCX2-B16) and CCR7-overexpressing B16 cells (CCR7-B16) in murine footpads and compared resulting tumors at the protein and mRNA level using immunostaining, Affymetrix gene microarray and quantitative reverse-transcriptase PCR. Although control and CCR7-B16 primary tumors were of similar size, LN metastasis was dramatically enhanced in CCR7-B16 tumors. Microarray analysis of leukocyte-depleted pLNCX2-B16 and CCR7-B16 tumor cell suspensions showed that three major groups of genes linked to interferon (IFN)-γ signaling pathways (for example, STAT1, CXCR 9-11, CCL5 and CXCL10, major histocompatibility complex (MHC) I and MHC II) were downregulated in the CCR7-B16 tumor microenvironment, suggesting activation through CCR7 can downregulate pathways critical for host anti-tumor immunity. In addition, mRNA expression of the lymphatic marker podoplanin was upregulated in CCR7-B16 tumors by 3.35-fold versus control tumors. Anti-podoplanin monoclonal antibody staining revealed a three-fold increase in intratumoral CCL21-expressing lymphatic vessels, as well as a two-fold increase in the number of invading tumor cells per lymphatic vessel in CCR7-B16 versus control tumors. Enhanced anti-vascular endothelial growth factor C (VEGF-C) staining was present in CCR7-B16 versus control tumors, suggesting that VEGF-C may have a role in the CCR7-mediated lymphangiogenesis. In summary, CCR7-B16 tumors show a striking decrease in IFN-γ-mediated inflammatory gene expression in contrast to increased expression of VEGF-C, CCL21 and podoplanin by lymphatic vessels. Enhanced lymphangiogenesis may contribute to the dramatic increase in LN metastasis that is observed in the CCR7-expressing tumors.

Impaired cerebral vasoreactivity in white coat hypertensive adolescents.

BACKGROUND AND PURPOSE: Although its incidence is not high, adolescent hypertension may predict hypertension and increased cardiovascular risk in adulthood. Therefore, the aim of the present study was to assess whether cerebrovascular reactivity is altered in adolescent white coat and sustained hypertensive patients compared to healthy teenagers. METHODS: Fifty-nine normotensive, 47 white coat hypertensive (WCH), and 73 sustained hypertensive (SH) adolescents were studied. WCH and SH were differentiated by ambulatory blood pressure monitoring. Cerebrovascular reactivity was assessed by transcranial Doppler breath-holding test and was expressed in percent (%) change to the resting cerebral blood flow velocity value. RESULTS: The percent increase in middle cerebral artery mean blood flow velocity after 30 s of breath holding was lower in both WCH (5.3 ± 3.1%) and SH (9.5 ± 2.6%) groups indicating lower vasodilatory reactivity compared to healthy adolescents (12.1 ± 2.2%). Additionally, serum nitric oxide (NOx) concentrations were lower in both WCH (30.6 ± 11 µM) and SH (30.7 ± 22.4 µM) groups compared to controls (38.8 ± 7.6 µM). CONCLUSIONS: Both white coat and sustained hypertension result in decreased vasodilatory reaction to CO(2) in adolescents, suggesting involvement of the cerebral arterioles. The present study underlines the importance of early recognition and proper treatment of adolescent hypertension in order to prevent long-term cardiovascular complications.

Relationship of adipokines and non-esterified fatty acid to the insulin resistance in non-diabetic individuals.

BACKGROUND: Altered secretion of adipokines and non-esterified fatty acid (NEFA) seems to play a pivotal role in the abdominal obesity-related insulin resistance (IR). AIM: To determine semi-quantitatively the impact of serum NEFA, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), leptin, adiponectin, and resistin levels on IR measured by homeostasis model assessment (HOMA-IR). MATERIAL/SUBJECTS: Seventy-four Caucasian subjects forming 3 age-, and sex-matched groups were included into the study [Group 1 and 2: non-diabetic obese patients, no.= 25, body mass index (BMI): 28-39.9 kg/m(2), no.=25, BMI≥40 kg/m(2), respectively, and Group 3: 24 healthy, normal weight control subjects]. METHODS: Serum levels of NEFA and adipokines as well as other metabolic variables including HOMA-IR were measured. RESULTS: HOMA-IR was associated positively with BMI, waist circumference, serum NEFA, leptin, IL-6, and TNF-α levels, negatively with adiponectin, with no significant relation to resistin. In multiple regression analyses, of these factors leptin was a strong, IL-6 and adiponectin were weak independent predictors of HOMA-IR, while the others were not significant determinants of HOMA-IR. However, even together, they explained only 35-36% of variance of HOMAIR. CONCLUSIONS: Although IR has associations with many of the investigated parameters, of these, only serum level of leptin, and in lesser degree IL-6 and adiponectin are independent determinants of the severity of IR. Moreover, even together they explain only a minority of variance IR.

Evaluation of the thyroid function of healthy pregnant women by five different hormone assays.

A normal function of the thyroid gland during pregnancy is essential. Any change can affect both the pregnant woman and the fetus. Thyroid hormones play a crucial role in the brain development of the fetus, thus proper maternal free thyroid hormone levels are important especially during the first trimester. We compared the free thyroid hormone levels FT3 and FT4 in forty pregnant women with no thyroidal disease by five different assays available on the market. The blood samples were collected between the 8th and 22nd weeks of pregnancy. The correlation coefficient "r" between different assays was 0.908-0.975 for TSH, 0.676-0.892 for FT4 and 0.480-0.789 for FT3. These data show that the inter-assay results varied widely in the studied population. One reasonable explanation may be that during pregnancy the serum levels of the thyroid hormone binding proteins are altered and "free" hormone measurements by immunoassays are influenced by these alterations. Thus, the results may show higher or lower thyroid hormone values depending upon the assay used. Therefore, it is strongly suggested that every laboratory should establish its own pregnant reference ranges for the tests used for the evaluation of thyroid function, based on values of the population served.

Improved endothelial function and lipid profile compensate for impaired hemostatic and inflammatory status in iatrogenic chronic subclinical hyperthyroidism of thyroid cancer patients on L-t4 therapy.

OBJECTIVE: We aimed to compare the changes of endothelial function and haemostatic, inflammatory and metabolic parameters of short-term iatrogenic hypothyroidism to the characteristics of subclinical hyperthyroidism in patients with differentiated thyroid cancer. DESIGN: Twenty four women (mean age 42.4+/-8.1 years) had undergone total thyroidectomy and radioiodine ablation in treatment for differentiated thyroid cancer. We measured serum thyroglobulin, thyroid function, plasma levels of lipid parameters, homocystine, C-reactive protein, fibrinogen, von Willebrandt factor activity (vWF), nitric oxide, as well as flow-mediated vasodilatation (FMD) and nitroglycerin-mediated vasodilatation of the brachial artery during iatrogenic hypothyroidism (TSH 89.82+/-29.36 mU/L) and again in the same patients during subclinical hyperthyroidism secondary to exogenous levothyroxine administration (TSH 0.24+/-0.11 mU/L). RESULTS: In hypothyroidism, FMD was markedly lower than in subclinical hyperthyroidism (6.79+/-4.44 vs. 14.37+/-8.33%, p<0.005). Total cholesterol (7.34+/-1.23 vs. 4.75+/-1.14 mmol/L, p<0.001), LDL-cholesterol (4.55+/-1.10 vs. 2.70+/-0.89 mmol/L, p<0.005) and homocystine (12.95+/-4.49 vs. 9.62+/-2.29 micromol/L, p<0.005) were significantly higher in hypothyroidism. There was no difference in nitroglycerin-mediated vasodilatation, blood pressure, serum triglyceride and HDL-cholesterol levels according to thyroid function. Fibrinogen (3.23+/-0.50 vs. 4.01+/-0.84 g/L, p<0.005), vWF (90.09+/-25.92 vs.130.63+/-29.97%, p<0.001), C-reactive protein (4.39+/-5.16 vs. 5.55+/-5.15 mg/L, p<0.001) and plasma nitric oxide (24.56+/-6.71 vs. 32.34+/-7.0 micromol/L, <0.005) values were significantly lower in hypothyroidism. FMD correlated in a positive manner with fibrinogen, vWF and nitrogen oxide. CONCLUSIONS: Chronic subclinical hyperthyroidism was associated with improved endothelial function and lipid profile, while haemostatic and inflammatory parameters were impaired. The two opposite mechanisms may well compensate for each other at the level of the vessel wall.

Relationship of serum resistin level to traits of metabolic syndrome and serum paraoxonase 1 activity in a population with a broad range of body mass index.

UNLABELLED: The relationship between resistin, one of the adipokines, and metabolic syndrome is not fully elucidated. Altered activity of the HDL-associated antioxidant enzyme paraoxonase 1 (PON1) that participates in the antioxidant defense mechanisms of HDL may have an important role in the obesity-related accelerated atherosclerosis. Inverse associations of PON1 with obesity and serum levels of leptin have been demonstrated. Our aim was to investigate the association of serum levels of resistin with (i) PON1 activity, and (ii) parameters of metabolic syndrome, including some that are additional for research. A total of 74 Caucasian subjects were recruited into the study and divided into 3 age and sex-matched groups. Group 1, 25 non-diabetic overweight/obese subjects with BMI of 28-39.9 kg/m (2); group 2, 25 non-diabetic obese patients with BMI >or=40 kg/m (2); and the control group 3, 24 healthy, normal-weight control subjects. Serum levels of resistin were correlated negatively with BMI (r=-0.27, P<0.05), waist circumference (r=-0.28, P<0.05), serum levels of leptin (r=-0.28, P<0.05), non-esterified fatty acids (NEFA) (r=-0.23, P<0.05), and HbA (1C) (r=-0.26, P<0.05), systolic BP (r=-0.28, P<0.05), and lipid peroxidation (measured by TBARS) (r=-0.40, P<0.01), and correlated positively with PON1 (r=0.24, P<0.05). No association was detected between the serum concentrations of resistin and the following investigated parameters: diastolic BP, levels of uric acid, glucose, insulin, or insulin resistance (measured by homeostasis model assessment, HOMA-IR), triglyceride, total cholesterol, LDL-C, and HDL-C. During multiple regression analyses BMI and TBARS were independent predictors of PON1, while age, gender, blood pressure, HOMA-IR, LDL-C, HDL-C, and resistin were not. CONCLUSIONS: Among the study subjects, serum levels of resistin showed a positive, although not independent correlation with serum PON1, and a negative correlation with numerous parameters of the metabolic syndrome (i.e. adiposity, blood pressure, levels of leptin, free fatty acid, glycosylated hemoglobin, and lipid peroxidation). BMI and TBARS are independent predictors of PON1 activity.

Correlation between the activities of lipoprotein lipase and paraoxonase in type 2 diabetes mellitus.

UNLABELLED: In type 2 diabetes mellitus the decreased catabolism of triglyceride-rich lipoproteins as a consequence of mainly the decreased lipoprotein lipase activity results in hypertriglyceridaemia and other lipoprotein alterations promoting atherosclerosis. The high-density lipoprotein-associated enzyme, paraoxonase, prevents the oxidation of low-density lipoprotein, which is an antiatherogenic effect. AIM: to examine the relation between the activities of enzymes influencing HDL remodelling- LPL and PON- in type 2 diabetes mellitus. METHODS: 56 newly diagnosed type 2 diabetic patients and 39 healthy controls were involved in the study. The serum PON activity was measured spectrophotometrically using paraoxone as substrate. PON phenotype was determined by the dual substrate method, PON mass was measured by ELISA. The determination of lipoprotein lipase activity was performed using 3H-triolein. RESULTS: We noticed smaller PON activity decrease in our newly diagnosed diabetic subjects compared to the previous studies which investigated the alteration of enzyme activity after a longer duration of diabetes mellitus. The lipoprotein lipase activity showed a positive correlation with PON activity (r=0.43; P<0.02). Interestingly, the PON activity of the homozygous-low activity group did not correlate with the LPL activity, while in the heterozygous and homozygous-high activity groups there was a significantly positive correlation (r=0.51; P<0.05) between PON and LPL activity. CONCLUSION: Besides lipid alterations, the metabolic changes of type 2 diabetes mellitus influence the reduction of the antioxidant capacity of HDL by remodelling HDL and decreasing PON activity via modification of lipoprotein lipase activity, which might contribute to accelerated atherosclerosis.

Nongenomic effect of thyroid hormone on free-radical production in human polymorphonuclear leukocytes.

Over the past few years increasing evidence has suggested the nongenomic effects of thyroid hormone, such as the activation of the signal transduction pathways and the activation of nuclear factor-kappaB by the induction of oxidative stress. The present study was undertaken to investigate the effect of thyroid hormone on human polymorphonuclear leukocytes (PMNLs) which are known as important sources of reactive oxygen species in the circulation. The production of superoxide anion (O2-) and the activity of myeloperoxidase were determined in the presence and absence of several inhibitors of the signalling pathway. L-thyroxine (T4) l-3,5,3'-tri-iodothyronine (T3) and L-3,5-di-iodothyronine (T2) stimulated O2- production in PMNLs in a dose-dependent manner within a few minutes of addition to cells. Thyroid hormone-stimulated O2- production was partially inhibited by pertussis toxin, an inhibitor of GTP-binding G protein, and was completely abolished by the protein kinase C inhibitors calphostin C and Ro-32-0432, and by a calcium chelator (BAPTA; bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid). Thyroid hormone stimulated myeloperoxidase activity and induced 125I- incorporation into PMNLs. Furthermore, thyroid hormone pre-incubation enhanced O2- production for n-formyl-methionyl-leucyl- phenylalanine (FMLP) stimulation. In conclusion, novel nongenomic actions of thyroid hormone, the induction of superoxide anion production and the stimulation of myeloperoxidase activity in PMNLs were demonstrated. The induction of O2- production requires calcium and is mediated by a pertussis toxin-sensitive G protein via stimulation of protein kinase C(s). These results suggest the existence of a membrane-bound binding site for thyroid hormone in PMNLs and a physiological role for thyroid hormone in the cellular defence mechanisms by stimulating free-radical production.

Effect of short term treatment with simvastatin and atorvastatin on lipids and paraoxonase activity in patients with hyperlipoproteinaemia.

OBJECTIVE: High-density lipoprotein (HDL)-associated paraoxonase (PON) activity may play an important role in the inhibition of low-density lipoprotein (LDL) oxidation. Previous studies have demonstrated that serum PON activity is decreased in patients with hyperlipoproteinaemia and coronary heart disease. The study presented here examined the effect of short-term treatment with simvastatin and atorvastatin on lipids and PON activity in patients with hyperlipoproteinaemia. RESEARCH DESIGN AND METHODS: A prospective, non-blinded, single-group, cross-over, comparative trial was performed. Following an 8-week dietary run-in period, 49 patients (23 men and 26 women, mean age: 59.8 +/- 7.9 years) with Fredrickson type IIa. and IIb. hyperlipoproteinaemias were randomized to receive either simvastatin 20 mg/day or atorvastatin 10 mg/day for 3 months. Following an 8-week washout period, patients were crossed-over to receive the other drug for a further 3 months. Serum lipids were measured and serum PON activity was determined spectrophotometrically using paraoxon as a substrate. RESULTS: Simvastatin treatment significantly reduced serum cholesterol, LDL-cholesterol (LDL-C) and apolipoprotein (apo) B levels (p < 0.001). Atorvastatin had a more pronounced cholesterol, LDL-C- and apo B-lowering effect (p < 0.001) compared with simvastatin. Both statins also significantly reduced serum triglyceride levels (p < 0.01). Simvastatin and atorvastatin caused no significant change in the levels of HDL-cholesterol (HDL-C) and apo A1. HDL-associated PON activity did not change significantly after simvastatin therapy, but significantly increased after atorvastatin treatment (p < 0.05). CONCLUSIONS: Short-term administration of simvastatin did not increase PON activity. Atorvastatin treatment had a favourable effect on lipid profile and increased the activity of HDL-associated PON.

Disturbed regulation of cholesterol synthesis in monocytes of obese patients with hypercholesterolemia.

The aim of the present study was to clarify the influence of obesity on the functions of low-density lipoprotein receptors (LDL-R) and 3-hydroxy-3-methylglutarate-coenyzme A (HMG-CoA) reductase both in healthy control subjects and in patients with hypercholesterolemia (HC). Experiments were performed on monocytes of 15 non-obese (C I) and 11 obese (C II) healthy control subjects and on 22 non-obese (HC I) and 26 obese (HC II) patients with HC. [(125)I]LDL was used to determine LDL-R activity by measuring binding and intracellular degradation. The rate of endogenous cholesterol synthesis was measured using [(14)C]acetate incorporation into the cholesterol fraction of monocytes. The binding ability of [(125)I]LDL was identical across all groups. The [(14)C]acetate incorporation in resting monocytes was increased only in obese HC group. The 50-microg/mL LDL protein-induced inhibition of [(14)C]acetate incorporation was significantly diminished (P <.001) in the same group. A strong positive correlation was detected between the [(14)C]acetate incorporation by resting cells and LDL-induced inhibition in all groups except the obese HC group, in which their correlation was negative (P <.001). Furthermore, in the obese HC group, a significant positive correlation was detected between body mass index (BMI) and the basal level of [(14)C]acetate incorporation, whereas a negative correlation was found between BMI and LDL-induced inhibition of [(14)C]acetate incorporation. The present data suggest that in patients with HC the concomitant obesity results in dysregulation of cholesterol homeostasis, which may contribute to the accelerated atherosclerosis.