A fully validated simple new method for environmental monitoring by surface sampling for cytotoxics.

A wipe sampling procedure followed by a simple ultra-performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneous quantification of six cytotoxic drugs: 5-fluorouracil (5FU), doxorubicin (DOXO), epirubicin (EPI), ifosfamide (IF), cyclophosphamide (CP) and gemcitabine (GEM), as surrogate markers for occupational exposure. After a solid-phase extraction of wiping filter on 10 × 10 cm surface, the separation was performed within 6.5 min, using a gradient mobile phase and the analytes were detected by mass spectrometry in the multiple reaction ion monitoring mode. The method was validated according to the recommendations of the US Food and Drug Administration. The method was linear (r2 > 0.9912) between 2.5 and 200 ng per wiping sample (25 to 2000 pg/cm2) for 5FU, doxorubicin and epirubicin and between 0.2 and 40 ng per wiping sample (2 to 400 pg/cm2) for cyclophosphamide, ifosfamide and gemcitabine. The lower limits of quantification were 2.5 ng (25 pg/ cm2) for 5FU, doxorubicin and epirubicin, and 0.2 ng (2 pg/cm2) for CP, IF and GEM. Within-day and between-day imprecisions were <14.0, 10.6, 11.1, 8.7, 11.2 and 10.9% for 5-fluorouracil, doxorubicin, epirubicin, ifosfamide cyclophosphamide and gemcitabine, respectively. The inaccuracies did not exceed 2.7, 10.9, 1.1, 4.5, 1.6 and 2.9% for the studied molecules, respectively. This new sensitive validated method for surface contamination studies of cytotoxics was successfully applied on different localizations in hospital. This approach is particularly suitable to assess occupational exposure risk to cytotoxic drugs.

Diabetes and dyslipidaemia are associated with oxidative stress independently of inflammation in long-term antiretroviral-treated HIV-infected patients.

AIM: Ageing HIV-infected patients controlled by antiretroviral therapy (ART) frequently present age-related comorbidities, such as cardiovascular (CV) events, diabetes, dyslipidaemia, hypertension and chronic kidney disease (CKD). The prevalence of these comorbidities was evaluated in a cohort of long-term-monitored ART-controlled HIV-infected patients, then followed by a search into whether oxidative stress, like inflammation, might be associated with metabolic parameters and/or comorbidities. METHODS: Included were 352 long-term ART patients who started with protease inhibitors (PIs) in 1997-1999. They were evaluated at their final visit, 11 years later, for previous CV events, prevalence of diabetes, LDL-related and atherogenic (high TG/HDL) dyslipidaemias, hypertension and CKD. Also measured were circulating biomarkers to explore oxidative stress (Lp-PLA2, oxLDL, oxLDL/LDL ratio, paraoxonase and arylesterase activities), inflammation/immune activation (hsCRP, hsIL-6, D dimer, soluble CD14, ß2 microglobulin, cystatin C), adipokines and insulin resistance. Levels were compared in patients with and without each comorbidity or condition using non-parametric correlation tests and multivariate adjusted analyses. RESULTS: At the final visit, 81.5% of patients were male and were aged (median, IQR) 49 years (45-56); BMI was 23.0 kg/m2 (21.1-25.4), CD4+ lymphocytes were 620 cells/mm3 (453-790) and 91.5% had undetectable HIV-1 viral loads. The prevalence of diabetes was 11%, and LDL-related dyslipidaemia 28%, atherogenic dyslipidaemia 9%, hypertension 28%, CKD 9% and previous CV events 9%. Diabetes and atherogenic dyslipidaemia were associated with increased oxidative stress and independently with inflammation. LDL-related dyslipidaemia and impaired fasting glucose were associated with increased oxidative stress. No association of these biomarkers was detected with hypertension, CKD and previous CV events. CONCLUSION: In long-term-treated HIV-infected patients with frequent comorbid conditions, oxidative stress could be contributing to diabetes and LDL-related and atherogenic dyslipidaemias independently of inflammation.

Effect of phytosterols/stanols on LDL concentration and other surrogate markers of cardiovascular risk.

Plant sterols and stanols are well-known to reduce LDL-cholesterol (LDL-C) concentrations. It is generally accepted that supplementation with 2g/day of sterols/stanols leads to a 10% reduction in LDL. However, most of the clinical trials supporting this conclusion were of short-term duration, and the results of longer interventions are scanty. In four studies, interventions lasting>6 months were carried out and the LDL-C-lowering effects were maintained over this longer duration, although some results suggest that a reduced effect may be observed with sterols, while stanols maintain their effect. In any case, the data are too limited to be definitive. In a free-living population as well as in multiparametric interventional studies, however, the LDL-C-lowering effect has been confirmed, although to a lesser extent than in clinical studies. In the absence of data on cardiovascular morbidity and mortality, data for surrogate markers of cardiovascular risk could be considered adequate alternatives. Several studies have been conducted on this basis, but their results failed to demonstrate any favourable effects. The present report summarizes the different results obtained in long-term studies, and in those comparing the effects of sterols and stanols on lipids and other surrogate markers of cardiovascular risk.

The anti-proliferative and pro-apoptotic effects of the trans9, trans11 conjugated linoleic acid isomer on MCF-7 breast cancer cells are associated with LXR activation.

Conjugated linoleic acids (CLA), naturally found in dairy products and ruminant meat, are positional and geometric isomers (trans: t or cis: c) of linoleic acid, and have been widely reported to possess anti-tumoral activity against breast cancer both in vitro and in vivo. CLA isomer t9,t11 was recently proposed as an agonist of the transcriptional factor LXR, which is known for inducing genes implicated in cholesterol efflux. In this study, the growth inhibitory effect of three CLA isomers (c9,t11-CLA, t9,t11-CLA and t10,c12-CLA) was investigated on MCF-7 breast cancer cells, as well as their effect on LXR target genes. Our results revealed that t9,t11-CLA was the most efficient isomer by decreasing MCF-7 proliferation, inhibiting migration, and inducing apoptosis after 24h of treatment. t9,t11-CLA treatment led to an increase in the mRNA levels of LXR target genes involved in cholesterol efflux (ABCG1 and ARL7), as well as an increase of HMG-CoA-reductase which is the rate-limiting step of cholesterol biosynthesis. Interestingly, confocal microscopy analysis showed that t9,t11-CLA treatment remarkably reduced the intracellular and membrane-associated cholesterol levels. LXR activation through t9,t11-CLA isomer could lead to cholesterol cell deprivation by stimulating its efflux, which results in the inhibition of cell proliferation and stimulation of apoptosis.

Evaluation of digestive tolerance of a soluble corn fibre.

BACKGROUND: To assess consumers' acceptance of a new fibre, it is essential to evaluate its digestive tolerance after ingestion. We aimed to determine the tolerance of increasing dosages of Promitor™ Soluble Gluco Fibre (SGF; Tate&Lyle, Hoffman Estates, IL, USA) up to 70 g fibre per day using a validated gastrointestinal composite score. METHODS: A composite score of gastrointestinal tolerance integrating gastrointestinal symptoms, stool frequency and consistency was applied. To statistically validate this composite score, the gastrointestinal tolerance of inulin (10 g versus 20 g containing, respectively, 9 g versus 18 g of fibre) was assessed in 18 healthy volunteers in a randomised double-blind placebo-controlled cross-over study. Second, in a double-blind placebo-controlled cross-over study with 20 healthy volunteers, the gastrointestinal tolerance of SGF in both acute and 'spread over the day' conditions of consumption was assessed. RESULTS: By contrast to 10 g, 20 g of inulin demonstrated a significant difference in composite score compared to placebo [P < 0.001, difference = 7.6; 95% confidence interval (CI) = 3.8-11.3]. These values were considered as reference during the second study. In acute conditions, 40 g of SGF fibre was the highest (threshold) dose tested that indicates the digestive tolerance criteria (difference from placebo on the composite score <7.6 and upper limit of the 95% CI <11.3); this is twice the amount tolerated for inulin. In 'spread over the day' conditions, 65 g of SGF fibre was the threshold dose (P < 0.001, difference = 6.5; 95% CI = 3.4-9.5). CONCLUSIONS: The results of the present study demonstrate that 40 g of SGF fibre, when consumed as a single dose, and 65 g of SGF fibre, when consumed in multiple-doses, across the day are well-tolerated by healthy volunteers.

Development and validation of an improved liquid chromatography-mass spectrometry method for the determination of pemetrexed in human plasma.

An improved liquid chromatography-mass spectrometry method for the determination of pemetrexed in human plasma was developed and validated using a simple quadrupole LC-MS and a new SPE cartridge (Plexa Bond Elut). The analysis was achieved with a C18 analytical column using a mobile phase consisting of formic acid/acetonitrile and isocratic flow for 7 min. The linear ranges (r(2)>0.99) were found from 5 to 5000 ng/mL. The lower limit of detection was 2.5 ng/mL. Within-day and between-day precisions were less than 7.2% and inaccuracy did not exceed 2.8%. This new method is suitable to support pharmacokinetic studies and drug monitoring.

[PPAR alpha-L162V, frequency and relationship with type 2 diabetes among black Senegalese people]. / PPARalpha-L162V: fréquence et relation avec le diabète de type 2 dans une population noire sénégalaise.

PPARs are supposed to be involved in pathogenesis of diabetes and its complications. According to some authors, L162V PPARalpha gene polymorphism would be associated to dyslipidemia susceptibility during diabetes, whereas for some authors, it rather would confer resistance to these metabolic abnormalities. The aim of this study is to search the relationship between this polymorphism and the occurrence of diabetes and its complications within a Senegalese black population constituted of 261 diabetic and 128 controls, by comparing alleles frequencies. Genomic analysis for alleles identification has been performed by the allelic discrimination technic TaqMan 5' Nuclease, after DNA extraction (Nucleon Bacc2. Amersham Int.). The results of genetic variants analysis revealed that L162V PPARalpha polymorphism would not be present among Senegalese black population, and consequently, should not be involved in diabetes onset.

Influence of atorvastatin on apolipoprotein E and AI kinetics in patients with type 2 diabetes.

Atorvastatin reduces both plasma cholesterol and triglyceride concentrations in patients with type 2 diabetes, but mechanisms underlying triglyceride decrease and the effect of atorvastatin on high density lipoprotein (HDL) still remain unclear. Apolipoprotein (apo) E plays a crucial role in modulating production and clearance of triglyceride-rich very low density lipoprotein (VLDL). The main effect of apoAI is to modulate HDL metabolism. The aim of this work was to study the influence of atorvastatin on apoAI and apoE kinetics and to determine whether its hypocholesterolemic and hypotriglyceridemic effects could be related to changes in this apolipoprotein metabolism. Plasma VLDL-apoE, HDL-apoE, and HDL-apoAI were studied in seven patients with diabetes with mixed hyperlipidemia using a stable isotope labeling technique ([(2)H3]leucine-primed constant infusion) and monocompartmental model before and after 2 months of treatment with 40 mg/day of atorvastatin. Plasma apoE concentration was significantly reduced (44.1 +/- 19.1 versus 32 +/- 11.6 mg/l, p < 0.05) after treatment. This decrease was associated with a diminution of HDL-apoE concentration (17.46 +/- 6.71 versus 13.37 +/- 6.05 mg/l, p < 0.05) and production rate (0.202 +/- 0.085 versus 0.119 +/- 0.047 mg/kg/day, p < 0.05), whereas an increase in VLDL-apoE concentration (6.44 +/- 2.16 before versus 9.23 +/- 4.02 mg/l after, p < 0.05) and production rate (0.827 +/- 0.367 versus 1.524 +/- 0.664 mg/kg/day, p < 0.05) was observed. No significant difference was observed after treatment for apoAI parameters. We conclude that atorvastatin treatment promotes different apoE distribution between HDL and VLDL, favoring VLDL apoE content. The increased number of apoE per VLDL particle suggests that atorvastatin could enhance the direct catabolism of triglyceride-rich VLDL through apoE receptor pathways.

Childhood obesity and insulin resistance in a Yucatan mini-piglet model: putative roles of IGF-1 and muscle PPARs in adipose tissue activity and development.

OBJECTIVE: To explore metabolic and cellular modifications induced during childhood obesity, in a novel animal model of obese mini-piglets. DESIGN: A total of 10 four-month old Yucatan mini-pigs were followed from prepuberty to adulthood. Animals were divided into two groups. The first one had been overfed (OF) a western-type diet and the second one had been normally fed a control recommended human-type diet (NF). MEASUREMENTS: Plasma insulin-like growth factor 1 (IGF-1), insulin, leptin, nonesterified fatty acids, triglycerides (TGs) and glucose were determined at sexual maturity and at young adulthood. Quantitative gene expressions of peroxysome-proliferator-activated receptors (PPARs), glucose transporter 4, insulin receptor, IGF-1, leptin and interleukin-6 (IL-6) in skeletal muscle, adipose tissue and liver were also measured at both stages. Adult insulin sensitivity was measured via euglycaemic-hyperinsulinaemic clamps. RESULTS: Increased body weight in adult OF pigs was associated with increased body size and low insulin sensitivity. Sexually mature OF pigs had higher IGF-1 plasma concentrations than their lean littermates (P < 0.05). In the OF group, TGs and glucose were both decreased (P < 0.05). Muscle PPARgamma and alpha in OF pubescent pigs as compared to NF pigs were 11 times higher and 20 times lower, respectively (P < 0.01). CONCLUSION: Obesity and insulin resistance induced by overfeeding mini-pigs during development and puberty were not associated with the cluster of metabolic modifications frequently observed in their adult littermates. Increased IGF-1 concentrations and modifications of skeletal muscle PPAR (alpha and gamma) expressions may help the young obese pig to partially regulate its glycaemia and triglyceridaemia through an increase of fat mass, which maintains its high insulin sensitivity.

Effect of LPS on basal and induced apo E secretion by 25-OH chol and 9cRA in differentiated CaCo-2.

The infection and inflammation process is associated with disturbances in lipid and lipoprotein metabolism. The apolipoprotein E (apo E) plays an important role in the lipoprotein metabolism and has been linked to inflammatory disease such as atherosclerosis and Alzheimer disease. An anti-inflammatory effect has also been suggested. The heterodimer nuclear receptor Liver-X-Receptor(alpha)/Retinoid-X-Receptor (LXR(alpha)/RXR) is considered to be a transcription factor for apo E. The aim of this study was to determine whether lipopolysaccharide (LPS) (principal component of the outer membrane Gram-negative bacteria) has an effect on apo E secretion by intestinal mucosa cells, using the Caco-2 cell line. Differentiated Caco-2 cells grown on filter inserts were incubated apically with LPS and/or 25-hydroxycholesterol (25-OH chol) and 9 cis retinoic acid (9cRA), ligands of LXR and RXR, respectively. The apical and basolateral media were separately collected. Apo E was detected by specific antibodies after protein separation by Two-dimensional nondenaturing gradient gel electrophoresis and apo E secreted in the cell culture media was measured by enzyme linked immunosorbent assay (ELISA). Apo E mRNA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). LXR(alpha) and RXR mass was analyzed by Western Blot. We demonstrate here that CaCo-2 cells secrete apo E, by either apical or basolateral sides, associated with a high-density like lipoprotein, with a stoke's diameter comprised between 7.10 and 8.16 nm. We show that only apical secretion is decreased by LPS in a dose and time dependent manner. This is associated with a decrease in apo E gene expression contrasting with an increase of Il-8, a chemokine factor. Moreover, we demonstrate that only basolateral apo E secretion by CaCo-2 is significantly increased by 25-OH chol and 9cRA while apical secretion remains unchanged. LPS does not decrease the 25-OH chol and 9cRA mediated apo E secretion in basolateral compartment, while apical secretion is diminished under these circumstances. Our results provide evidence for the polarized secretion of apo E by intestinal epithelium. They also demonstrate that apo E secretion by CaCo-2 cell line is decreased by LPS through an LXR(alpha)/RXR independent signaling pathway.

Postprandial changes in the distribution of apolipoprotein AIV between apolipoprotein B- and non apolipoprotein B-containing lipoproteins in obese women.

Plasma apolipoprotein AIV (apo AIV) level has been shown to be a good marker of triglyceride changes after a high-fat diet. However, the distribution of apo AIV between apo B- and non-apo B-containing lipoproteins (Lp) during the postprandial state has not been described as well as the influence of obesity on this distribution. Our aim was to study the influence of parameters related to obesity and insulin resistance on the postprandial changes in apo AIV-containing Lp after a high-fat meal in obese women. Twenty-three overweight or obese women (body mass index [BMI] ranging from 29.1 and 64.0 kg.1 m(-2)), for whom blood samples were taken after fasting overnight, participated in the study. Thirteen of these obese women were given a fatty meal and, in this case, blood samples were taken at fast and 30 minutes, 1, 2, 4, and 6 hours after ingestion of the fat meal. Apo AIV-containing particle families, Lp B:AIVf (family [f] of particles containing at least apo B and apo AIV) and Lp AIV non-Bf (family [f] of particles containing apo AIV, but free of apo B) were quantified by sandwich enzyme-linked immunosorbent assay (ELISA). When fasting, Lp B:AIVf and Lp AIV non-Bf did not correlate with any of the parameters related to obesity and insulin resistance, if one excepts a positive correlation between HDL-cholesterol (HDL-C) and Lp AIV non-Bf. Postprandial lipemia was associated with a trend towards an increase in the plasma levels of apo AIV-containing Lp 6 hours after fat ingestion. The postprandial peak of Lp B:AIVf and Lp AIV non-Bf occurred 2 hours after the triglyceride peak. The distribution between apo B- and non-apo B-containing Lp did not change after ingestion of the fat meal, if one excepts a tendancy towards a lower ratio of bound and nonbound forms at 8 hours. Fasting plasma Lp B:AIVf concentration correlated with the area under the curve (AUC) of plasma triglycerides (beta = 0.11, P <.02). In a multivariate analysis, BMI (beta = 51.85, P <.001), fasting triglycerides (beta = 431.08, P <.01), and low-density lipoprotein-cholesterol (LDL-C) (beta = 2638.57, P <.005) were independent and positive determinants of the AUC of Lp AIV non-Bf, while waist circumference (beta = -23.94, P <.001), cholesterol (beta = -1655.02, P <.01), and systolic blood pressure (beta = -6.34, P <.05) were negative and independent determinants of this AUC. Fasting Lp B:AIVf may represent a good marker of the postprandial triglyceride increase in obese women. Changes in apo AIV concentrations in apo B- and non-apo B-containing Lp after a fat meal depend mainly on the degree of obesity rather than on insulin resistance. This effect is more obvious for Lp AIV non-Bf than for Lp B:AIVf.

Apolipoprotein E kinetics: influence of insulin resistance and type 2 diabetes.

BACKGROUNDS AND AIMS: Insulin resistance related to obesity and diabetes is characterized by an increase in plasma TG-rich lipoprotein concentrations. Apolipoprotein (apo) E plays a crucial role in the metabolism of these lipoproteins and particularly in the hepatic clearance of their remnants. The aim of this study was to explore apoE kinetics of obese subjects and to determine what parameters could influence its metabolism. METHODS: Using stable-isotope labelling technique ([(2)H(3)]-leucine-primed constant infusion) and monocompartmental model (SAAM II computer software), we have studied the plasma kinetics of very-low-density lipoprotein (VLDL) and high-density lipoprotein (HDL) apoE in 12 obese subjects (body mass index (BMI) 27.4-36.6 kg/m(2)): Seven were type 2 diabetics (age 47-65 y; HbA1c 7.1-10.2%) and five were non-diabetics (age 40-51 y, HbA1c: 4.9-5.3%). Six of the diabetic subjects were insulin resistant as assessed by insulin sensitivity index (HOMA 2.6-10.0), while non-diabetic subjects were all insulin sensitive (HOMA 1.2-2.1). RESULTS: Plasma VLDL and HDL apoE concentrations were significantly higher in diabetic than in non-diabetic subjects (5.74+/-1.60 vs 1.46+/-1.74 mg/l, P<0.01 and 17.81+/-6.67 vs 9.97+/-3.32 mg/l, P<0.05). These increased levels were associated with significantly higher absolute production rate (APR) of VLDL and HDL apoE (0.714+/-0.343 vs 0.130+/-0.200 mg/kg/day, P<0.01, and 0.197+/-0.087 vs 0.080+/-0.060 mg/kg/day, P<0.05, respectively) while no significant difference was found for fractional catabolic rate (FCR) of VLDL and HDL apoE (3.44+/-1.64 vs 1.97+/-0.84/day and 0.30+/-0.12 vs 0.19+/-0.09/day, respectively). In the whole population, BMI was not correlated with any of apoE kinetic data. HOMA was positively correlated with FCR of VLDL apoE (r=0.64, P<0.05) and tended to be correlated with APR of VLDL apoE (r=0.58, P=0.06). HbA1c was positively correlated with APR and FCR of both VLDL apoE (r=0.91 and 0.78, P<0.01, respectively) and HDL apoE (r=0.66 and 0.69, P<0.05, respectively). CONCLUSION: Obese diabetics are characterized by elevated VLDL and HDL apoE levels associated with enhancement of VLDL and HDL apoE production rates. Whereas obesity did not influence apoE kinetic parameters in itself, insulin resistance may lead to an increase in VLDL apoE production and fractional catabolic rates. Diabetes and the glycemic control may also specifically influence the kinetics of both VLDL and HDL apoE. All together, these disorders should explain at least part of the increase in VLDL and HDL apoE observed in diabetes.

In vivo evidence for the role of lipoprotein lipase activity in the regulation of apolipoprotein AI metabolism: a kinetic study in control subjects and patients with type II diabetes mellitus.

The aim of this study was to delineate the role of lipoprotein lipase (LPL) activity in the kinetic alterations of high density lipoprotein (HDL) metabolism in patients with type II diabetes mellitus compared with controls. The kinetics of HDL were studied by endogenous labeling of HDL apolipoprotein AI (HDL-apo AI) using a primed infusion of D(3)-leucine. The HDL-apo AI fractional catabolic rate (FCR) was significantly increased (0.32 +/- 0.07 vs. 0.23 +/- 0.05 pool/day; P < 0.01), and HDL composition was changed [HDL cholesterol, 0.77 +/- 0.16 vs. 1.19 +/- 0.37 mmol/L (P < 0.05); HDL triglycerides, 0.19 +/- 0.12 vs. 0.10 +/- 0.03 mmol/L (P < 0.05)] in diabetic patients compared with healthy subjects. HDL-apo AI FCR was correlated to plasma and HDL triglyceride concentrations (r = 0.82; P < 0.05 and r = 0.80; P < 0.05, respectively) and to homeostasis model assessment (r = 0.78; P < 0.05). Postheparin plasma LPL activity was decreased in type II diabetes (6.8 +/- 2.8 vs. 18.1 +/- 5.2 micromol/mL postheparin plasma.h; P < 0.005) compared with that in healthy subjects and was correlated to the FCR of HDL-apo AI (r = -0.63; P < 0.05). LPL activity was also correlated with HDL cholesterol (r = 0.78; P < 0.05), plasma and HDL triglycerides (r = -0.87; P < 0.005 and r = -0.83; P < 0.05, respectively), and homeostasis model assessment (r = -0.79; P < 0.05). In addition, the LPL to hepatic lipase ratio was correlated with the catabolic rate of HDL (r = -0.76; P < 0.06). These results suggest that a decrease in the LPL to hepatic lipase ratio in type II diabetes mellitus, mainly related to lowered LPL activity, could induce an increase in HDL catabolism. These alterations in HDL kinetics in type II diabetes proceed to some extent from changes in their composition, probably linked to an increase in triglyceride transfer from very low density lipoprotein particles, in close relationship with LPL activity and resistance to insulin.

Accumulation of triglyceride-rich lipoprotein in subjects with abdominal obesity: the biguanides and the prevention of the risk of obesity (BIGPRO) 1 study.

The present study represents a new insight into the Biguanides and the Prevention of the Risk of Obesity (BIGPRO) 1 study population at inclusion. This population, selected basically on the basis of a high waist-to-hip ratio (>/=0.95 for men and >/=0.80 for women), is supposed to represent a group of patients with insulin resistance. The present study was undergone to establish whether apolipoprotein C-III (apoC-III) and apolipoprotein E (apoE) associated with apo B (apoC-III LpB and apoE LpB, respectively), considered to be markers of remnant accumulation, play a role in the hypertriglyceridemia associated with insulin resistance and whether they are related to other biological abnormalities frequently observed in this syndrome. In this population, the concentration of the markers of remnant accumulation increases with triglyceride levels. Therefore, correlation studies were realized to assess the relative effect of insulin and the markers of remnant accumulation on triglyceride plasma level. As a first attempt, a simple correlation analysis revealed that insulin is positively related to the markers of remnant accumulation only in hypertriglyceridemic patients (triglycerides >/=1.7 mmol/L). To assess the independent contribution of these markers, insulin, and other parameters related to the plasma triglyceride concentration, a stepwise multiple regression analysis was run. Results revealed that insulin and the markers of remnant accumulation (specifically, apoE LpB) are independent contributors to the plasma triglyceride concentration. Markers of the endothelial damage, plasminogen activator inhibitor-1, tissue plasminogen activator, and von Willebrand factor, which are often increased in the case of insulin resistance, were tested for their correlation with the markers of remnant accumulation. Plasminogen activator inhibitor-1 is positively correlated with these markers only in hypertriglyceridemic male subjects. It is concluded that increased insulin levels found in insulin resistance syndrome are associated with an increased production of triglyceride-rich lipoproteins enriched in apoC-III and apoE. The accumulation of these remnants and/or their abnormal composition in apoC-III and apoE could be an explanation for the development of hypertriglyceridemia in this syndrome.

Influence of remnant accumulation markers on plasma concentrations of two lipoprotein(a) subspecies (containing or free of apoE).

Lipoprotein(a) [Lp(a)], an atherosclerosis marker, has 2 subspecies differing in structure and composition that can easily be distinguished by the presence or absence of apolipoprotein E (apoE). The subspecies containing apo E [Lp(a):B:E] is found mainly in the very-low-density lipoprotein (VLDL) size range, while that free of apoE [Lp(a):B] is found mainly in the LDL size range. As little is known about the physiologic function of these subspecies, this study investigated Lp(a):B and Lp(a):B:E concentrations in a population of normotriglyceridemic and moderately hypertriglyceridemic subjects in fasting state and attempted to determine the parameters influencing their plasma concentrations. The subjects studied (n = 98) had a mean total Lp(a) concentration of 108 mg/dL (28 to 252, minimum to maximum), a mean Lp(a):B concentration of 92.6 mg/dL (5 to 254), and a mean Lp(a):B:E concentration of 15.6 mg/dL (0 to 137). These results indicate that Lp(a):B:E, even in normolipidemic subjects, constitutes a detectable part of total Lp(a), ie, a mean percentage of 16.2% (0% to 96%). Multiple stepwise regression analyses showed that triacylglycerol has no independent effect on the concentration of Lp(a) subspecies, and that remnant accumulation markers, such as the E/LpB:E molar ratio (number of apoE per particle containing both apoB and apoE) and apoE-LpB (mass of apoE bound to particles containing both apoB and apoE), have a strong independent effect on this concentration. A strong positive influence of E/LpB:E on Lp(a):B:E subspecies was noted, as well as a negative influence of apo E-LpB on Lp(a):B subspecies. Taken together, these results suggest that the apoE bound to LpB:E particles plays a dominant role in the concentration of Lp(a) subspecies and that a redistribution of Lp(a) subspecies occurs under the influence of the apoE content of triacylglycerol-rich lipoprotein particles.

Negative and independent influence of apolipoprotein E on C-reactive protein (CRP) concentration in obese adults. Potential anti-inflammatory role of apoE in vivo.

BACKGROUND: Obesity is frequently associated with an increase in the early inflammation marker C-reactive protein (CRP), insulin resistance and changes in lipoprotein metabolism. Increased CRP is known as an independent cardiovascular risk factor. Since the apolipoproteins (apo) E and CIII components of HDL are associated with reduced cardiovascular risk and since apoE has in vitro anti-inflammatory effect, we have investigated the relationships between apoE, apoCIII (in apoB and non apoB containing lipoproteins) and CRP in obese adults. METHODS: The following parameters from 34 healthy obese fasting women (age 22-64 y, body mass index (BMI) 28-68 kg/m2) were measured: (1) ApoE and apoCIII, in total plasma, in apoB- (E LpB, CIII LpB) and non-apoB-containing lipoproteins (E LpnonB, CIII LpnonB); (2) CRP and cytokine secreted by adipose tissue (TNF-alpha and its soluble receptor TNFR2); (3) triglyceride, HDL-cholesterol, systolic blood pressure, diastolic blood pressure, waist and hip circumferences, insulin, glucose. HOMA, a marker of insulin sensitivity, and the ratio E/CIII in LpB and LpnonB were calculated. RESULTS: CRP was positively correlated with BMI (P<0.05), waist circumference (WC, P<0.05), triglyceride (P<0.05) and negatively correlated with apoE (P<0.01) and E LpnonB (P<0.05). Two multiple regression models including parameters related to CRP with a P<0.25 were run stepwise to assess their independent contribution to CRP concentration. In the first model (including BMI, WC, HOMA, insulin, triglyceride, apoE, E LpnonB), apoE was the best predictor of CRP (P=0.01) together with triglyceride (P=0.02) and BMI (P=0.08). The second model took into account E/CIII LpnonB ratio with the parameters included in the first model. In this second model, E/CIII LpnonB was the best predictor of CRP (P=0.007), explaining 39% of CRP variance. CONCLUSION: ApoE is strongly correlated with CRP and could have an anti-inflammatory effect in vivo in obese subjects. This correlation could be limited to LpnonB lipoproteins, depending on their apoE and CIII relative content.

The relationship between apolipoprotein AI-containing lipoprotein fractions and environmental factors: the prospective epidemiological study of myocardial infarction (PRIME study).

Apolipoprotein (apo) AI is distributed within high-density lipoproteins (HDL) between different types of particles, one containing both apoAI and apoAII (LpAI:AII), the other containing no apoAII (LpAI). We investigated the associations between LpAI and LpAI:AII with several factors such as body mass index (BMI), waist to hip ratio (WHR), alcohol intake, cigarette consumption and physical activity, in three French and one Northern Irish male populations included in a prospective study (PRIME study). LpAI and LpAI:AII were associated with variations in all environmental factors, except LpAI:AII, which was not associated with WHR. These relationships were unchanged after adjustment for other environmental factors, but slightly modified after adjustment for triglyceride levels. LpAI decreased when BMI, WHR and cigarette smoking increased, and increased with alcohol consumption and physical activity. LpAI:AII had a similar variation except for the absence of LpAI:AII modification associated with WHR variation. The associations between LpAI and BMI, alcohol consumption and cigarette smoking were largely dependent on HDL-cholesterol as indicated by the lack of any significance when the adjustment for HDL-cholesterol was made. Conversely, after adjustment for HDL-cholesterol, the significant association between LpAI:AII and BMI disappeared, while the associations between LpAI:AII and alcohol consumption, cigarette smoking and physical activity remained significant. These results suggest that the mechanisms of LpAI and LpAI:AII modulations differ according to each environmental factor, some dependent on the lipid content of lipoproteins and others not, but LpAI and LpAI:AII levels seem independent of triglyceride concentration.

Association of hypertensive status and its drug treatment with lipid and haemostatic factors in middle-aged men: the PRIME study.

AIMS: To assess the association of hypertensive status and antihypertensive drug treatment with lipid and haemostatic levels in middle-aged men. METHODS AND RESULTS: Hypertensive status, antihypertensive drug treatment, total and high-density lipoprotein (HDL) cholesterol, triglyceride, apoproteins A-I and B, lipoparticles LpA-I, LpE:B and Lp(a), fibrinogen, plasminogen activator inhibitor-1 (PAI-1) activity and factor VII were assessed in a sample of men 50-59 years living in France (n = 7050) and Northern Ireland (n = 2374). After adjustment for age, body mass index, smoking status, educational level, country, alcohol drinking and hypolipidaemic drug treatment, untreated hypertensive subjects had higher levels of total cholesterol, triglyceride, apoproteins A-I and B and PAI-I activity than normotensive subjects. On univariate analysis, diuretics decreased total and HDL-cholesterol and apoproteins A-I and B; those differences remained after multivariate adjustment. Treatment with beta-blockers decreased total and HDL-cholesterol, apoprotein A-I and LpA-I, and this effect remained after multivariate adjustment. Calcium channel blockers decreased total cholesterol and apoproteins A-I and B; those differences remained significant after multivariate adjustment. ACE inhibitors decreased total cholesterol, triglycerides, apoprotein B and LpE:B; and this effect remained after multivariate adjustment. Analysis of the subjects on monotherapy showed beta-blockers to decrease total cholesterol and HDL parameters and angiotensin-converting enzyme (ACE) inhibitors to decrease low-density lipoprotein (LDL)-related parameters, while no effect was found for the other antihypertensive drugs. CONCLUSIONS: Hypertensive status is associated with an unfavourable lipid and haemostatic profile in middle-aged men. Antihypertensive treatment with beta-blockers decreases HDL parameters, whereas treatment with ACE inhibitors appears to decrease total cholesterol and LDL-related parameters.

Plasma cholesterol and endogenous cholesterol synthesis during refeeding in anorexia nervosa.

Normal or high levels of cholesterol have been measured in patients with anorexia nervosa (AN). Given that cholesterol intake in AN is usually very low, the reasons for this anomaly are not clearly understood. We studied lipid and lipoprotein profiles and endogenous cholesterol synthesis, estimated by serum lathosterol, in a population of 14 girls with AN, before and during a period of 30 days refeeding. The initial body mass index (BMI) of the patients was 13.41+/-1.62 kg/m(2). No changes were observed during refeeding in endocrine parameters (ACTH, cortisol and estradiol). At Day 0 the lipids data measured here showed normal levels of triglycerides, and total cholesterol at the upper limits of the normal range (5.44+/-1 mmol/l). At this time, total and LDL cholesterol were negatively correlated with transthyretin and BMI. Serum lathosterol (a precursor in cholesterol synthesis pathway) increased significantly (5.99+/-1.75 (Day 0) vs. 8.39+/-2.96 (Day 30); P=0.02) while there was a significant decrease in apo B (0.79+/-0.33 (Day 0) vs. 0. 60+/-0.17 g/l (Day 30), P=0.02) with refeeding. Thus, patients with initial high cholesterol levels have the worst nutritional status and high cholesterol levels are not related to a de novo synthesis. This profile returns to normal with refeeding. An increase of cellular cholesterol uptake may be responsible for this apparently paradoxical evolution with increase of cholesterol synthesis and decrease of apo B during renutrition.