Increased erythrocytes n-3 and n-6 polyunsaturated fatty acids is significantly associated with a lower prevalence of steatosis in patients with type 2 diabetes.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is commonly associated with obesity, metabolic syndrome and type 2 diabetes. Although dietary fat contributes substantially to the accumulation of liver fat, the role of individual fatty acids in this accumulation is unclear. OBJECTIVE: In this study, we set out to determine whether liver fat content (LFC), was associated with red blood cell fatty acid (RBC-FA) composition in people with type 2 diabetes. DESIGN, SETTINGS, AND PARTICIPANTS: One hundred and sixty-two type 2 diabetic patients were included in this study. LFC was measured using (1)H-MR Spectroscopy. RBC-FA composition was measured by gas chromatography. RESULTS: One hundred and nine (67.2%) patients had steatosis. Patients with steatosis had a higher BMI (p = 0.0005), and higher plasma triglyceride levels (p = 0.009) than did patients without steatosis. We report a significant association between palmitic acid (16:0), palmitoleic acid (16:1n-7) concentrations and ratio of monounsaturated to saturated fatty acid (palmitoleic acid to palmitic acid) and higher liver fat content. Total polyunsaturated fatty acid (PUFA), homo-gamma-linolenic acid (20:3n-6), docosahexaenoic acid (22:6n-3), and arachidonic acid (20:4 n-6) were associated with lower LFC. CONCLUSIONS: Our data showed that an increased erythrocytes long-chain n-3 and n-6 fatty acids was associated with a lower prevalence of steatosis in patients with type 2 diabetes. These results suggest that n-3 and n-6 fatty acids supplementation could be a promising treatment for NAFLD in patients with type 2 diabetes.

Impact of obesity on the prognostic value of the N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with acute myocardial infarction.

OBJECTIVE: To examine the influence of obesity on the predictive value of the pro-B-type natriuretic peptide (NT-proBNP) assay in acute myocardial infarction. DESIGN: Prospective observational study. SETTING: All intensive care units in one region of France. Patients 2217 consecutive patients admitted for an acute myocardial infarction matched with respect to age, gender, Killip class and renal function. MAIN OUTCOME MEASURE: Cardiovascular death at one year. RESULTS: There were three groups (according to body mass index (BMI): obese, overweight and normal) of 739 matched patients. Median levels of NT-proBNP were considerably lower in high BMI patients, by about 20% in overweight and by 60% in obese patients, compared with normal BMI patients. An inverse relationship between the propeptide values and BMI was found in the overall study population (r = -0.20, p < 0.0001), and for both genders. In multivariate linear regression, BMI as a continuous variable was a predictor of the log NT-proBNP level, even when adjusted for potential confounders. CV mortality at 1-year follow-up was similar for the three BMI groups (p = 0.691). In multivariate logistic regression analysis, log NT-proBNP predicted mortality in normal (OR (95% CI) 3.48 (2.00 to 6.12)) and overweight (OR (95% CI) 3.96 (1.95 to 8.06)) patients, even when adjusted for confounders (GRACE risk score, left ventricular ejection fraction). However, in obese patients, propeptide levels failed to retain their independent prognostic value (OR (95% CI) 1.34 (0.86 to 2.08)). CONCLUSIONS: In this large population of patients with myocardial infarction, circulating NT-proBNP levels were considerably lower in obese patients; the significance of the propeptide level as an independent prognostic factor is severely compromised.

Prognostic value of N-terminal pro-brain natriuretic peptide in elderly people with acute myocardial infarction: prospective observational study.

OBJECTIVE: To examine the influence of age on the predictive value of N-terminal pro-brain natriuretic (NT-proBNP) peptide assay in acute myocardial infarction. DESIGN: Prospective observational study. SETTING: All intensive care units in one French region. PARTICIPANTS: 3291 consecutive patients admitted for an acute myocardial infarction, from the RICO survey (a French regional survey for acute myocardial infarction). MAIN OUTCOME MEASURE: Cardiovascular death at 1 year. RESULTS: Among the 3291 participants, mean age was 68 (SD 14) years and 2356 (72%) were men. In the study population, the median NT-proBNP concentration was 1053 (interquartile range 300-3472) pg/ml. Median values for age quarters 1 to 4 were 367 (119-1050), 696 (201-1950), 1536 (534-4146), and 3774 (1168-9724) pg/ml (P<0.001). A multiple linear regression analysis was done to determine the factors associated with the pro-peptide concentrations in the overall population. NT-proBNP was mainly associated with age, left ventricular ejection fraction, creatinine clearance, female sex, hypertension, diabetes, and anterior wall infarction. At one year's follow-up, 384 (12%) patients had died from all causes and 372 (11%) from cardiovascular causes. In multivariate analysis, NT-proBNP remained strongly associated with the outcome, beyond traditional risk factors including creatinine clearance and left ventricular ejection fraction, in each age group except in the youngest one (<54 years) (P=0.29). The addition of NT-proBNP significantly improved the performance of the statistical model in the overall study population (-2log likelihood 3179.58 v 3099.74, P<0.001) and in each age quarter including the upper one (1523.52 v 1495.01, P<0.001).The independent discriminative value of NT-proBNP compared with the GRACE score was tested by a diagonal stratification using the median value of the GRACE score and NT-proBNP in older patients (upper quarter). Such stratification strikingly identified a high risk group-patients from the higher NT-proBNP group and with a high risk score-characterised by a risk of death of almost 50% at one year. CONCLUSIONS: In this large contemporary non-selected cohort of patients with myocardial infarction, NT-proBNP concentration had incremental prognostic value even in the oldest patients, above and beyond the GRACE risk score and traditional biomarkers after acute myocardial infarction. These data further support the potential interest of clinical trials specifically assessing NT-proBNP measurement as a guide to current treatment strategies, as well as novel strategies, in older patients with acute myocardial infarction.

Effects of 20 mg rosuvastatin on VLDL1-, VLDL2-, IDL- and LDL-ApoB kinetics in type 2 diabetes.

AIMS/HYPOTHESIS: In addition to its efficacy in reducing LDL-cholesterol, rosuvastatin has been shown to significantly decrease plasma triacylglycerol. The use of rosuvastatin may be beneficial in patients with type 2 diabetes, who usually have increased triacylglycerol levels. However, its effects on the metabolism of triacylglycerol-rich lipoproteins in type 2 diabetic patients remains unknown. METHODS: We performed a randomised double-blind crossover trial of 6-week treatment with placebo or rosuvastatin 20 mg in eight patients with type 2 diabetes who were being treated with oral glucose-lowering agents. In each patient, an in vivo kinetic study of apolipoprotein B (ApoB)-containing lipoproteins with [13C]leucine was performed at the end of each treatment period. A central randomisation centre used computer-generated tables to allocate treatments. Participants, caregivers and those assessing the outcomes were blinded to group assignment. RESULTS: Rosuvastatin 20 mg significantly reduced plasma LDL-cholesterol, triacylglycerol and total ApoB. It also significantly reduced ApoB pool sizes of larger triacylglycerol-rich VLDL particles (VLDL1; p = 0.011), smaller VLDL particles (VLDL2; p = 0.011), intermediate density lipoprotein (IDL; p = 0.011) and LDL (p = 0.011). This reduction was associated with a significant increase in the total fractional catabolic rate of VLDL1-ApoB (6.70 +/- 3.24 vs 4.52 +/- 2.34 pool/day, p = 0.049), VLDL2-ApoB (8.72 +/- 3.37 vs 5.36 +/- 2.64, p = 0.011), IDL-ApoB (7.06 +/- 1.68 vs 4.21 +/- 1.51, p = 0.011) and LDL-ApoB (1.02 +/- 0.27 vs 0.59 +/- 0.13, p = 0.011). Rosuvastatin did not change the production rates of VLDL2-, IDL- or LDL-, but did reduce VLDL1-ApoB production rate (12.4 +/- 4.5 vs 19.5 +/- 8.4 mg kg(-1) day(-1), p = 0.035). No side effects of rosuvastatin were observed during the study. CONCLUSIONS/INTERPRETATION: In type 2 diabetic patients rosuvastatin 20 mg not only induces a significant increase of LDL-ApoB catabolism (73%), but also has favourable effects on the catabolism of triacylglycerol-rich lipoproteins, e.g. a significant increase in the catabolism of VLDL1-ApoB (48%), VLDL2-ApoB (63%) and IDL-ApoB (68%), and a reduction in the production rate of VLDL1-ApoB (-36%). The effects of rosuvastatin on the metabolism of triacylglycerol-rich lipoproteins may be beneficial for prevention of atherosclerosis in type 2 diabetic patients.

Distinct patterns of heparin affinity chromatography VLDL1 and VLDL2 subfractions in the different dyslipidaemias.

Very low density lipoprotein (VLDL) 1 and 2 were fractionated by heparin affinity chromatography into a bound and an unbound fraction and the different subfractions were quantified in 17 normolipidaemic (NL), 13 hypercholesterolaemic (HC), 10 hypertriglyceridaemic (HTG) and 11 combined hyperlipidaemic subjects (CHL). Unbound VLDL1 and VLDL2 were, respectively, 1.9- and 2.2-fold richer in triglycerides than bound VLDL1 and VLDL2. In HTG and CHL the concentration of all the VLDL subfractions was increased and plasma triglyceride level was correlated to unbound VLDL1 and to bound VLDL1 (respectively, r=0.86 (p<0.001) and r=0.77 (p<0.01) in HTG and r=0.73 (p<0.001) and r=0.62 (p<0.05) in CHL). In HC unbound VLDL2 and bound VLDL2 concentration were increased compared to NL and in CHL, the concentration of bound VLDL2 was particularly increased (3.2-fold compared to NL (p<0.001)). In both HC and CHL bound VLDL2 concentration was correlated to low density lipoprotein cholesterol (LDL-C) concentration (respectively, r=0.67 (p<0.01) and r=0.62 (p<0.05)). In hypertriglyceridaemic states the intravascular accumulation of both unbound and bound VLDL1 appears as the determinant of plasma triglyceride concentration, whereas in moderately hypercholesterolaemic states the concentration of bound VLDL2 is strikingly correlated to LDL-C concentration, suggesting that these two species are linked metabolically, e.g. bound VLDL2 contain the precursor pool of LDL.

Lipid levels and cardiovascular risk in elderly women: a general population study of the effects of hormonal treatment and lipid-lowering agents.

OBJECTIVE: To evaluate plasma lipid levels in elderly women in the general population as a function of use of lipid-lowering agents (LLA) and hormone therapy (HT). METHODS: A total of 4271 women aged over 65 years were recruited from three French cities. Analyses were performed after stratification by LLA treatment and HT and adjusting for a large range of sociodemographic and clinical factors. RESULTS: Fifteen percent of women currently used HT (78% transdermal estradiol), and 30% were taking LLA. In this population, 4.6% of women were taking both HT and LLA (fibrate for 2.4% and statin for 2.2%). In non-LLA-treated women, current HT was associated with lower total cholesterol, low density lipoprotein cholesterol (LDL-C), and non-high density lipoprotein cholesterol (non-HDL-C) compared to never users. Women treated with LLA also had lower total cholesterol, LDL-C, and non-HDL-C compared to non-LLA users, whereas triglyceride levels were the highest in statin users and lowest in fibrate users. Fibrate use was associated with a more favorable lipid pattern than statin treatment independently of HT use. In women without coronary heart disease or diabetes, HT, statin or fibrate use were associated with lower LDL-C level risk based on National Cholesterol Education Program guidelines (adjusted odds ratio (OR) = 0.67 (95% confidence interval (CI) = 0.53-0.85), 0.38 (95% CI = 0.29-0.47), and 0.32 (95% CI = 0.25-0.42), respectively) with a possible interaction between fibrate and HT (0.18 (95% CI = 0.10-0.30)). CONCLUSIONS: Estradiol-based HT may lower atherogenic lipoproteins in postmenopausal women. In primary prevention of coronary heart disease, combining HT and a fibrate may provide additional benefits compared to fibrate use.

HDL particles from type 1 diabetic patients are unable to reverse the inhibitory effect of oxidised LDL on endothelium-dependent vasorelaxation.

AIMS/HYPOTHESIS: In healthy individuals, HDL can counteract the inhibition of vasorelaxation induced by oxidised LDL. Several abnormalities such as increased size, glycation and decreased paraoxonase activity have been reported for HDL from type 1 diabetic patients. Thus, we hypothesised that the ability of HDL to protect vessels against impairments of vasorelaxation would be decreased in these patients. METHODS: We compared the ability of HDL from 18 type 1 diabetic patients and 12 control participants to counteract the inhibition of endothelium-dependent relaxation induced by oxidised LDL on rabbit aorta rings. RESULTS: Serum triacylglycerol and total cholesterol, LDL- and HDL-cholesterol were similar in type 1 diabetic and control participants. Fasting glycaemia and the HDL-fructosamine level were higher in diabetic patients than in controls (9.06 +/- 3.55 vs 5.27 +/- 0.23 mmol/l, p < 0.005; and 10.2 +/- 3.2 vs 7.7 +/- 2.5 micromol/g protein, p < 0.05, respectively). HDL composition, size and paraoxonase activity were similar in both groups. HDL from controls reduced the inhibitory effect of oxidised LDL on maximal relaxation (E (max); 79.3 +/- 11.8 vs 66.4 +/- 11.7%, p < 0.05), whereas HDL from type 1 diabetic patients had no effect (E (max) = 70.6 +/- 17.4 vs 63.9 +/- 17.2%, NS). In type 1 diabetic patients, E (max) was not correlated with glycaemia or the HDL-fructosamine level. CONCLUSIONS/INTERPRETATION: HDL particles from type 1 diabetic patients do not protect against inhibition of endothelium-dependent vasorelaxation induced by oxidised LDL, in contrast to HDL particles from healthy individuals. This defect cannot be explained by abnormalities in HDL composition, size or paraoxonase activity, and may contribute to the early development of atherosclerotic lesions in type 1 diabetic patients.

Hemodialysis reduces plasma apolipoprotein C-I concentration making VLDL a better substrate for lipoprotein lipase.

Apolipoprotein Cs (apoC-1, apoC-II, and apoC-III) are lipoprotein components that have regulatory effects on enzymes involved in lipoprotein metabolism. Owing to their low molecular weights, apoCs can adsorb onto and/or pass through dialysis membranes. Our study determines the consequence of hemodialysis (HD) on plasma concentrations of apoCs and on the activities of enzymes modulated by apoCs. Plasma samples were collected from 28 patients with chronic renal failure before and after HD. Plasma apoC-II levels were unchanged, whereas apoC-III levels were slightly decreased in post-dialysis plasmas. The apoC-I content was markedly reduced during HD. This was due to a significant decrease in the apoC-I content of very low-density lipoprotein (VLDL), whereas the apoC-I content of high-density lipoprotein (HDL) was unchanged. Although HDL bound apoC-I is thought to inhibit cholesterol ester transfer protein, no change in the ability of pre- and post-dialysis VLDL to interact with the transfer protein were observed. Complementary experiments confirmed that VLDL-bound apoC-I has no transfer protein inhibitory potential. In contrast, an increase in the ability of post-dialysis apoC-I-poor VLDL to act as substrate for lipoprotein lipase (LPL) was found compared to pre-dialysis VLDL. Our study shows that apoC-I losses during HD might be beneficial by improving the ability of VLDL to be a substrate for LPL thus improving plasma triglyceride metabolism.

High levels of N-terminal pro B-type natriuretic peptide are associated with ST resolution failure after reperfusion for acute myocardial infarction.

BACKGROUND: B-type natriuretic peptide and the N-terminal fragment of its prohormone, N-terminal pro-brain natriuretic peptide (Nt-proBNP), provide valuable prognostic information on short- and long-term mortality in patients with acute coronary syndrome AIM: To investigate the association between plasma NT-proBNP levels and ST-segment resolution (STR) after reperfusion in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: Consecutive patients from the French regional RICO survey with STEMI who were treated by primary PCI or lysis <12 h were included. Blood sample was taken on admission to measure plasma NT-proBNP. Maximal ST segment elevation was measured on the single worst ECG lead before and 90 min after reperfusion. Patients were categorized as STR(-) (<50% STR) or STR(+) (>or=50% STR). RESULTS: Of the 486 patients included, 133 (27%) were STR(-). STR(-) patients had similar cardiovascular risk factors but higher in-hospital mortality (5% vs. 1%, p=0.03) than STR(+) patients. The STR(-) group had higher median (IQR) levels of Nt-proBNP: 938 (211-3272) vs. 533 (169-1471) pg/ml, p=0.003. On multivariate analysis, the highest quartile of Nt-ProBNP, Q waves and lysis were independent risk factors for incomplete STR. DISCUSSION: Our data show a strong association between high levels of Nt-proBNP at admission and incomplete STR, suggesting that Nt-proBNP may be useful for early risk stratification in reperfusion therapy after acute myocardial infarction.

Inability of HDL from type 2 diabetic patients to counteract the inhibitory effect of oxidised LDL on endothelium-dependent vasorelaxation.

AIMS/HYPOTHESIS: In healthy normolipidaemic and normoglycaemic control subjects, HDL are able to reverse the inhibition of vasodilation that is induced by oxidised LDL. In type 2 diabetic patients, HDL are glycated and more triglyceride-rich than in control subjects. These alterations are likely to modify the capacity of HDL to reverse the inhibition of vasodilation induced by oxidised LDL. SUBJECTS AND METHODS: Using rabbit aorta rings, we compared the ability of HDL from 16 type 2 diabetic patients and 13 control subjects to suppress the inhibition of vasodilation that is induced by oxidised LDL. RESULTS: Oxidised LDL inhibited endothelium-dependent vasodilation (maximal relaxation [Emax] = 58.2+/-14.6 vs 99.3+/-5.2% for incubation without any lipoprotein, p < 0.0001). HDL from control subjects significantly reduced the inhibitory effect of oxidised LDL on vasodilatation (Emax = 77.6+/-12.9 vs 59.5+/-7.7%, p < 0.001), whereas HDL from type 2 diabetic patients had no effect (Emax = 52.4+/-20.4 vs 57.2+/-18.7%, NS). HDL triglyceride content was significantly higher in type 2 diabetic patients than in control subjects (5.3+/-2.2 vs 3.1+/-1.4%, p < 0.01) and was highly inversely correlated to Emax for oxidised LDL+HDL in type 2 diabetic patients (r = -0.71, p < 0.005). CONCLUSIONS/INTERPRETATION: In type 2 diabetes mellitus, the ability of HDL to counteract the inhibition of endothelium-dependent vasorelaxation induced by oxidised LDL is impaired and is inversely correlated with HDL triglyceride content. These findings suggest that HDL are less atheroprotective in type 2 diabetic patients than in control subjects.

High circulating levels of 7beta- and 7alpha-hydroxycholesterol and presence of apoptotic and oxidative markers in arterial lesions of normocholesterolemic atherosclerotic patients undergoing endarterectomy.

In previous investigations, we found that 7beta-hydroxycholesterol had potent pro-apoptotic, and pro-oxidative properties. So, we asked whether the circulating level of this oxysterol was enhanced in atherosclerotic patients undergoing endarterectomy of the superficial femoral artery. To this end, 7beta-hydroxycholesterol serum concentrations were determined and compared with common lipid parameters in atherosclerotic patients, and in healthy subjects. 7alpha-hydroxycholesterol was simultaneously measured to evaluate the reliability of the method used for oxysterol analysis. On normal and atherosclerotic arterial fragments from patients, markers of oxidation (4-hydroxynonenal (4-HNE) adducts), and apoptosis (activated caspase-3; condensed/fragmented nuclei) were studied. Interestingly, high serum concentrations of 7beta- and 7alpha-hydroxycholesterol were found in normocholesterolemic atherosclerotic patients. However, in statin-treated patients, the circulating levels of 7beta- and 7alpha-hydroxycholesterol tend towards normal values. Therefore, 7beta- as well as 7alpha-hydroxycholesterol could be more appropriate markers of lipid metabolism disorders than cholesterol or LDL in normocholesterolemic patients with atherosclerosis of the lower limbs, and statins could normalize their serum concentrations. At the arterial level, apoptotic cells were mainly identified in low grade lesions and no statin effects were found on oxidation and apoptosis.

Effect of insulin treatment on plasma oxidized LDL/LDL-cholesterol ratio in type 2 diabetic patients.

OBJECTIVE: In type 2 diabetes mellitus, oxidized LDL/LDL-Cholesterol ratio, an accurate estimation of in vivo LDL oxidation, has been reported elevated and associated with macrovascular disease. Because insulin therapy induces significant modification of lipid metabolism, in type 2 diabetes, we evaluated the effect of insulin treatment on oxidized LDL/LDL-C ratio in type 2 diabetic patients and analyzed the results in comparison with the modifications induced by insulin on glycaemia, plasma lipids and LDL receptors. RESEARCH DESIGN AND METHODS: Plasma oxidized LDL concentrations were measured by sandwich ELISA in 21 type 2 diabetic patients before and 3 months after the introduction of insulin therapy, and in 27 age-matched controls. RESULTS: Type 2 diabetic patients had, compared to controls, significantly increased oxidized LDL/LDL-C ratio (P<0.0001). Three months after insulin treatment, oxidized LDL/LDL-C ratio was significantly reduced (21.1+/-4.7 vs. 24.0+/-5.8 U/mmol, P<0.01). This reduction was strongly associated, in multivariate analysis, with reduction of LDL(TG/cholesterol ratio) (P=0.008), and to a lesser extent with the decrease of LDL fructosamine (P=0.034), but not with the increase of the number of LDL receptors. CONCLUSIONS: In the present study we demonstrate for the first time a lowering effect of insulin therapy on oxidized LDL/LDL-C ratio in type 2 diabetic patients. This decrease is mainly associated with the reduction of LDL TG-enrichment, and to a lesser extent with the decrease of LDL glycation, but not with the insulin-induced increase in number of LDL receptors.

Comparison of the cytotoxic, pro-oxidant and pro-inflammatory characteristics of different oxysterols.

Oxidized low-density lipoproteins play important roles in the development of atherosclerosis and contain several lipid-derived, bioactive molecules which are believed to contribute to atherogenesis. Of these, some cholesterol oxidation products, referred to as oxysterols, are suspected to favor the formation of atherosclerotic plaques involving cytotoxic, pro-oxidant and pro-inflammatory processes. Ten commonly occurring oxysterols (7alpha-, 7beta-hydroxycholesterol, 7-ketocholesterol, 19-hydroxycholesterol, cholesterol-5alpha,6alpha-epoxide, cholesterol-5beta,6beta-epoxide, 22R-, 22S-, 25-, and 27-hydroxycholesterol) were studied for both their cytotoxicity and their ability to induce superoxide anion production (O2*-) and IL-8 secretion in U937 human promonocytic leukemia cells. Cytotoxic effects (phosphatidylserine externalization, loss of mitochondrial potential, increased permeability to propidium iodide, and occurrence of cells with swollen, fragmented and/or condensed nuclei) were only identified with 7beta-hydroxycholesterol, 7-ketocholesterol and cholesterol-5beta,6beta-epoxide, which also induce lysosomal destabilization associated or not associated with the formation of monodansylcadaverine-positive cytoplasmic structures. No relationship between oxysterol-induced cytotoxicity and HMG-CoA reductase activity was found. In addition, the highest O2*- overproduction quantified with hydroethidine was identified with 7beta-hydroxycholesterol, 7-ketocholesterol and cholesterol-5beta,6beta-epoxide, with cholesterol-5alpha, 6alpha-epoxide and 25-hydroxycholesterol. The highest capacity to simultaneously stimulate IL-8 secretion (quantified by ELISA and by using a multiplexed, particle-based flow cytometric assay) and enhance IL-8 mRNA levels (determined by RT-PCR) was observed with 7beta-hydroxycholesterol and 25-hydroxycholesterol. None of the effects observed for the oxysterols were detected for cholesterol. Therefore, oxysterols may have cytotoxic, oxidative, and/or inflammatory effects, or none whatsoever.

Normal metabolism of apolipoprotein B100-containing lipoproteins despite qualitative abnormalities in type 1 diabetic men.

AIMS/HYPOTHESIS: Type 1 diabetic subjects are at increased risk of cardiovascular disease and exhibit multiple qualitative abnormalities of apolipoprotein (apo) B100-containing lipoproteins. This stable isotope kinetic experiment was designed to study whether these abnormalities are associated with changes in the synthesis and fractional catabolic rates of VLDL-, IDL- and LDL-apoB100. METHODS: Using a bolus followed by a 16-h constant infusion of 13C-leucine, we performed a kinetic study in eight men with type 1 diabetes treated with a continuous subcutaneous insulin infusion administered by an external pump and in seven healthy men, in the fed state. RESULTS: The mean HbA1c level in the type 1 diabetic patients was 8.00+/-1.48%. Plasma triglyceride, and total, LDL and HDL cholesterol levels were similar in patients and control subjects. VLDL were less triglyceride rich in type 1 diabetic patients than in control subjects (VLDL triglyceride : apoB 6.91+/-0.81 vs 8.29+/-1.24 mmol/g, p=0.05). Conversely, the IDL and LDL of the type 1 diabetic patients contained relatively higher levels of triglycerides (IDL triglycerides : apoB 2.16+/-0.36 vs 1.57+/-0.30 mmol/g, p<0.01; LDL triglycerides : apoB 0.27+/-0.06 vs 0.16+/-0.04 mmol/g, p<0.05). The apoB100 pool size, production and fractional catabolic rates in the two groups of subjects were similar for all lipoprotein fractions. CONCLUSIONS/INTERPRETATION: Despite qualitative abnormalities, especially abnormalities of triglyceride content, the metabolism of apoB100-containing lipoproteins is not altered in type 1 diabetic men with fair glycaemic control with continuous subcutaneous insulin infusion. The high risk of atherosclerosis in these patients cannot be explained by kinetic abnormalities of apoB100-containing lipoproteins.

Serum adiponectin and metabolic parameters in HIV-1-infected patients after substitution of nevirapine for protease inhibitors.

BACKGROUND: In the context of HIV infection and antiretroviral therapy, adiponectin concentrations have been shown to be related to lipodystrophy, metabolic alterations and HIV-protease inhibitor (PI) use. The replacement of PI by nevirapine has improved the lipid profile of patients under antiretroviral therapy. The aim of the present study was to examine whether adiponectin concentration or insulin sensitivity level correlate with the modifications of lipid parameters after the switch of PI by nevirapine. MATERIAL AND METHODS: The evolution of metabolic parameters before and after 6 months of substitution of nevirapine for protease inhibitors was evaluated in a cohort of 55 HIV-1 infected patients. Adiponectin concentration, insulin sensitivity, lipid profile, cholesterol ester transfer protein (CETP) mass concentration and triglyceride enrichment of HDL were determined before and after the replacement of PI by nevirapine. Insulin sensitivity was evaluated by the HOMA model assessment. RESULTS: Twenty-four weeks of treatment with nevirapine improved significantly the lipid profile with a significant reduction of apoB (from 0.98 to 0.92 g L(-1); P = 0.005) and triglyceride (from 2.02 to 1.66 mmol L(-1); P = 0.02). HDL cholesterol and apoA1 increased significantly (from 0.99 to 1.19 mmol L(-1); P = 0.001 and from 1.40 to 1.57 g L(-1); P < 0.001, respectively). The triglyceride enrichment of HDL significantly decreased after the replacement of PI by nevirapine (from 0.248 +/- 0.092 to 0.213 +/- 0.093; P = 0.003). At baseline, and after 24 weeks of nevirapine treatment, we observed significant correlations between adiponectin level and lipid parameters [(HDL-cholesterol (r = 0.66, P = 0.001 and r = 0.69, P = 0.001); triglycerides (r = -0.42, P = 0.002 and r = -0.57, P = 0.001), and triglyceride enrichment of HDL (r = -0.43, P = 0.005 and r = -0.53, P = 0.005)]. Twenty-four weeks of treatment with nevirapine did not significantly change adiponectin concentrations (from 984 to 1086 micro g L(-1), P = 0.22), CETP mass and insulin sensitivity. CONCLUSION: This study shows that even though a strong correlation was found between adiponectin and some metabolic parameters at baseline and after 24 weeks of treatment by nevirapine, the improvement of lipid profile observed after the replacement of PI by nevirapine was not in relation to the change of plasma adiponectin concentration. The significant decrease of triglyceride enrichment of HDL after the replacement of PI by nevirapine probably leads to a decreased catabolism of HDL lipoprotein, and consequently explains the increase of plasma HDL concentration observed in this study.

Involvement of a calcium-dependent dephosphorylation of BAD associated with the localization of Trpc-1 within lipid rafts in 7-ketocholesterol-induced THP-1 cell apoptosis.

7-Ketocholesterol is a component of oxidized LDL, which plays a central role in atherosclerosis. It is a potent inducer of cell death towards a wide number of cells involved in atherosclerosis. In this study, it is reported that 7-ketocholesterol treatment induces an increase of cytosolic-free Ca(2+) in THP-1 monocytic cells. This increase is correlated with the induction of cytotoxicity as suggested from experiments using the Ca(2+) channel blockers verapamil and nifedipine. This 7-ketocholesterol-induced apoptosis appears to be associated with the dephosphorylation of serine 75 and serine 99 of the proapoptotic protein Bcl-2 antagonist of cell death (BAD). We demonstrated that this dephosphorylation results mainly from the activation of calcium-dependent phosphatase calcineurin by the oxysterol-induced increase in Ca(2+). Moreover, this Ca(2+) increase appears related to the incorporation of 7-ketocholesterol into lipid raft domains of the plasma membrane, followed by the translocation of transient receptor potential calcium channel 1, a component of the store operated Ca(2+) entry channel, to rafts.

[Microspheres, nanospheres and flow cytometry: from cellular to molecular analysis]. / Microbilles, nanobilles et cytométrie en flux: de l'analyse cellulaire à l'analyse moléculaire.

Micro- and nanospheres are tightly associated with the development of flow cytometry. They are indispensable tools to optimize diffraction and fluorescence signals as well as for fluorescence calibration and cellular purification (magnetic micro- and nanospheres). They are also usefull to evaluate phagocytosis and to detect slightly expressed antigens. Recently, developments of microspheres-based flow cytometric assays have raised to quantify soluble analytes in biological fluids, cellular and tissue samples. The technology utilizes spectrally distinct fluorescent microspheres as a solid support for a conventional immunoassay, affinity assay or DNA hybridisation assay which is subsequently analyzed on a flow cytometer. Several multiplexed bead systems are now available facilitating the development of multiplexed assays that simultaneously measure many different analytes in few microliters of sample. Some recent applications with fluorescent microspheres coated with antibodies or oligonucleotides include cytokines and PCR products quantitation and single nucleotide polymorphism genotyping. Thus, multiplex assays using microspheres and flow cytometry technologies are exciting techniques which have the potential to contribute to the development of efficient diagnostic and research methods.

[Flow cytometric study of low density lipoprotein receptors: biological and clinical interest]. / Etude du récepteur des lipoprotéines de basse densité par cytométrie en flux: intérêts biologiques et cliniques.

Low density lipoprotein (LDL) carry 60 to 80% of plasma cholesterol. These particules are mainly catabolized by LDL receptor. Thus, LDL receptor plays an important role in the regulation of plasma LDL cholesterol concentration, which is correlated to the risk of developing cardiovascular disease. The intracellular concentration of free cholesterol exerts a negative feedback on LDL receptor expression at the cell surface. This expression is also modulated by a lot of hormones, drugs and cytokines. On the other hand, mutations of LDL receptor induce familial hypercholesterolaemia, a frequent genetic disorder (1 to 500 births for the heterozygous form). Flow cytometry is a simple and fast technic, allowing to quantify LDL receptor expression at the cell surface and to study its functionality. Two different ligands can be used with flow cytometry: either fluorochrome-labelled LDL or anti-LDL receptor monoclonal antibody detected by a fluorescent secondary antibody. In immunofluorescent assays, we can now precisely calculate the number of LDL receptor at the cell surface by using calibration kits. In this article, we summarize the different regulatory factors of LDL receptor expression and present the advantages and limits of the different flow cytometry assays for LDL receptor analysis.

N-terminal pro-brain natriuretic peptide levels in patients with non-ST-elevation myocardial infarction.

METHODS AND RESULTS: 101 patients hospitalized for acute non-ST-elevation myocardial infarction (NSTEMI) were included in the study. Median N-terminal fragment of the brain natriuretic peptide (BNP) prohormone (Nt-proBNP) plasma level was 136 (40-335) pmol/l. Patients with increasing levels of troponin I [from low (0.1-10 ng/ml), intermediate (10-40 ng/ml) to high (> or =40 ng/ml) levels] had significantly increased levels of Nt-proBNP (p < 0.05). High-risk patients classified by a high PURSUIT score (i.e. supramedian) had significantly increased Nt-proBNP levels compared to patients with low scores (p < 0.001). Moreover, patients with in-hospital events (death, recurrent MI or clinical heart failure: 27%) had significantly increased median levels of Nt-proBNP compared to event-free patients (184 vs. 105 pmol/l, p = 0.02). CONCLUSION: Our data in an unselected population of NSTEMI patients indicate that high levels of circulating Nt-proBNP levels are associated with an increased risk of early cardiovascular events.

[Microbeads, nanobeads and cytometry: applications to the analysis and purification of cells and biomolecules]. / Microbilles, nanobilles et cytométrie: applications à l'analyse et à la purification cellulaire et moléculaire.

Nano and microspheres are important tools in cytometry. They have been used in first to optimize fluorescent signals detected by flow cytometry and to evaluate phagocytosis. Some antigens were also detected by using nanospheres covalently coupled to antibodies. Specifically dedicated microspheres are now widely used for antigenic quantitation by flow cytometry, and magnetic nano and micropheres are very usefull for cellular and molecular purifications. To date, analytical methods based on the use of microspheres are developed to detect proteins, nucleic acids, and ions. To this end, antibodies, oligonucleotides, or chelating agents are bound to microspheres characterized by different fluorescences. The applications of these multiplexed microspheres assays allow to identify and quantify simultaneously some macromolecules and ions, but they also permit to analyze enzymatic activities and to perform polymorphism analyses. With microspheres used as reactive support, molecular analyses are therefore possible by flow cytometry. Nano and microspheres are also usefull tools for calibration in confocal microscopy as well as for micromanipulations of biomolecules and of living cells. Inovative methods based on the use of nano and microspheres are expected in the fields of biology, medicine, food industry, and environmental sciences.