Interleukin-6 blockade raises LDL via reduced catabolism rather than via increased synthesis: a cytokine-specific mechanism for cholesterol changes in rheumatoid arthritis.

OBJECTIVES: Patients with rheumatoid arthritis (RA) have reduced serum low-density lipoprotein cholesterol (LDL-c), which increases following therapeutic IL-6 blockade. We aimed to define the metabolic pathways underlying these lipid changes. METHODS: In the KALIBRA study, lipoprotein kinetic studies were performed on 11 patients with severe active RA at baseline and following three intravenous infusions of the IL-6R blocker tocilizumab. The primary outcome measure was the fractional catabolic rate (FCR) of LDL. RESULTS: Serum total cholesterol (4.8 vs 5.7 mmol/L, p=0.003), LDL-c (2.9 vs 3.4 mmol/L, p=0.014) and high-density lipoprotein cholesterol (1.23 vs 1.52 mmol/L, p=0.006) increased following tocilizumab therapy. The LDL FCR fell from a state of hypercatabolism to a value approximating that of the normal population (0.53 vs 0.27 pools/day, p=0.006). Changes in FCR correlated tightly with changes in serum LDL-c and C-reactive protein but not Clinical Disease Activity Index. CONCLUSIONS: Patients with RA have low serum LDL-c due to hypercatabolism of LDL particles. IL-6 blockade normalises this catabolism in a manner associating with the acute phase response (and thus hepatic IL-6 signalling) but not with RA disease activity as measured clinically. We demonstrate that IL-6 is one of the key drivers of inflammation-driven dyslipidaemia.

miR-34a(-/-) mice are susceptible to diet-induced obesity.

OBJECTIVE: MicroRNA (miR)-34a regulates inflammatory pathways, and increased transcripts have been observed in serum and subcutaneous adipose of subjects who have obesity and type 2 diabetes. Therefore, the role of miR-34a in adipose tissue inflammation and lipid metabolism in murine diet-induced obesity was investigated. METHODS: Wild-type (WT) and miR-34a(-/-) mice were fed chow or high-fat diet (HFD) for 24 weeks. WT and miR-34a(-/-) bone marrow-derived macrophages were cultured in vitro with macrophage colony-stimulating factor (M-CSF). Brown and white preadipocytes were cultured from the stromal vascular fraction (SVF) of intrascapular brown and epididymal white adipose tissue (eWAT), with rosiglitazone. RESULTS: HFD-fed miR-34a(-/-) mice were significantly heavier with a greater increase in eWAT weight than WT. miR-34a(-/-) eWAT had a smaller adipocyte area, which significantly increased with HFD. miR-34a(-/-) eWAT showed basal increases in Cd36, Hmgcr, Lxrα, Pgc1α, and Fasn. miR-34a(-/-) intrascapular brown adipose tissue had basal reductions in c/ebpα and c/ebpß, with in vitro miR-34a(-/-) white adipocytes showing increased lipid content. An F4/80(high) macrophage population was present in HFD miR-34a(-/-) eWAT, with increased IL-10 transcripts and serum IL-5 protein. Finally, miR-34a(-/-) bone marrow-derived macrophages showed an ablated CXCL1 response to tumor necrosis factor-α. CONCLUSIONS: These findings suggest a multifactorial role of miR-34a in controlling susceptibility to obesity, by regulating inflammatory and metabolic pathways.

A genomic approach to therapeutic target validation identifies a glucose-lowering GLP1R variant protective for coronary heart disease.

Regulatory authorities have indicated that new drugs to treat type 2 diabetes (T2D) should not be associated with an unacceptable increase in cardiovascular risk. Human genetics may be able to guide development of antidiabetic therapies by predicting cardiovascular and other health endpoints. We therefore investigated the association of variants in six genes that encode drug targets for obesity or T2D with a range of metabolic traits in up to 11,806 individuals by targeted exome sequencing and follow-up in 39,979 individuals by targeted genotyping, with additional in silico follow-up in consortia. We used these data to first compare associations of variants in genes encoding drug targets with the effects of pharmacological manipulation of those targets in clinical trials. We then tested the association of those variants with disease outcomes, including coronary heart disease, to predict cardiovascular safety of these agents. A low-frequency missense variant (Ala316Thr; rs10305492) in the gene encoding glucagon-like peptide-1 receptor (GLP1R), the target of GLP1R agonists, was associated with lower fasting glucose and T2D risk, consistent with GLP1R agonist therapies. The minor allele was also associated with protection against heart disease, thus providing evidence that GLP1R agonists are not likely to be associated with an unacceptable increase in cardiovascular risk. Our results provide an encouraging signal that these agents may be associated with benefit, a question currently being addressed in randomized controlled trials. Genetic variants associated with metabolic traits and multiple disease outcomes can be used to validate therapeutic targets at an early stage in the drug development process.

Consumption of Fish Oil Providing Amounts of Eicosapentaenoic Acid and Docosahexaenoic Acid That Can Be Obtained from the Diet Reduces Blood Pressure in Adults with Systolic Hypertension: A Retrospective Analysis.

BACKGROUND: Although many randomized controlled trials (RCTs) have examined the effects of the n-3 (ω-3) fatty acids eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) on blood pressure (BP) and vascular function, the majority have used doses of EPA+DHA of >3 g/d, which are unlikely to be achieved by dietary manipulation. OBJECTIVE: The objective was to examine, by using a retrospective analysis from a multicenter RCT, the impact of recommended EPA+DHA intakes achievable through diet on systolic and diastolic BPs and microvascular function in adults in the United Kingdom. METHODS: In a double-blind, placebo-controlled RCT, healthy men and women (n = 312) consumed a control oil or fish oil (FO) providing 0.7 or 1.8 g EPA+DHA/d, in random order, each for 8 wk. Fasting BP and microvascular function (using laser Doppler iontophoresis) were assessed and plasma collected for the quantification of markers of vascular function. Participants were retrospectively genotyped for the endothelial nitric oxide synthase (eNOS) rs1799983 variant. RESULTS: No effects of n-3 fatty acid treatment or any treatment × eNOS genotype interactions were evident in the group as a whole for any of the clinical or biochemical outcomes. Assessment of response according to hypertension status at baseline indicated a significant (P = 0.046) FO-induced reduction (mean: 5 mm Hg) in systolic BP, specifically in those with isolated systolic hypertension (n = 31). No dose response was observed. CONCLUSIONS: These findings indicate that in adults with isolated systolic hypertension, daily doses of EPA+DHA as low as 0.7 g show clinically meaningful BP reductions, which, at a population level, could be associated with lower cardiovascular disease risk. Confirmation of findings in an RCT in which participants are prospectively recruited on the basis of BP status is required to draw definite conclusions.

Genetic associations with valvular calcification and aortic stenosis.

BACKGROUND: Limited information is available regarding genetic contributions to valvular calcification, which is an important precursor of clinical valve disease. METHODS: We determined genomewide associations with the presence of aortic-valve calcification (among 6942 participants) and mitral annular calcification (among 3795 participants), as detected by computed tomographic (CT) scanning; the study population for this analysis included persons of white European ancestry from three cohorts participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (discovery population). Findings were replicated in independent cohorts of persons with either CT-detected valvular calcification or clinical aortic stenosis. RESULTS: One SNP in the lipoprotein(a) (LPA) locus (rs10455872) reached genomewide significance for the presence of aortic-valve calcification (odds ratio per allele, 2.05; P=9.0×10(-10)), a finding that was replicated in additional white European, African-American, and Hispanic-American cohorts (P<0.05 for all comparisons). Genetically determined Lp(a) levels, as predicted by LPA genotype, were also associated with aortic-valve calcification, supporting a causal role for Lp(a). In prospective analyses, LPA genotype was associated with incident aortic stenosis (hazard ratio per allele, 1.68; 95% confidence interval [CI], 1.32 to 2.15) and aortic-valve replacement (hazard ratio, 1.54; 95% CI, 1.05 to 2.27) in a large Swedish cohort; the association with incident aortic stenosis was also replicated in an independent Danish cohort. Two SNPs (rs17659543 and rs13415097) near the proinflammatory gene IL1F9 achieved genomewide significance for mitral annular calcification (P=1.5×10(-8) and P=1.8×10(-8), respectively), but the findings were not replicated consistently. CONCLUSIONS: Genetic variation in the LPA locus, mediated by Lp(a) levels, is associated with aortic-valve calcification across multiple ethnic groups and with incident clinical aortic stenosis. (Funded by the National Heart, Lung, and Blood Institute and others.).

C-reactive protein, fibrinogen, and cardiovascular disease prediction.

BACKGROUND: There is debate about the value of assessing levels of C-reactive protein (CRP) and other biomarkers of inflammation for the prediction of first cardiovascular events. METHODS: We analyzed data from 52 prospective studies that included 246,669 participants without a history of cardiovascular disease to investigate the value of adding CRP or fibrinogen levels to conventional risk factors for the prediction of cardiovascular risk. We calculated measures of discrimination and reclassification during follow-up and modeled the clinical implications of initiation of statin therapy after the assessment of CRP or fibrinogen. RESULTS: The addition of information on high-density lipoprotein cholesterol to a prognostic model for cardiovascular disease that included age, sex, smoking status, blood pressure, history of diabetes, and total cholesterol level increased the C-index, a measure of risk discrimination, by 0.0050. The further addition to this model of information on CRP or fibrinogen increased the C-index by 0.0039 and 0.0027, respectively (P<0.001), and yielded a net reclassification improvement of 1.52% and 0.83%, respectively, for the predicted 10-year risk categories of "low" (<10%), "intermediate" (10% to <20%), and "high" (≥20%) (P<0.02 for both comparisons). We estimated that among 100,000 adults 40 years of age or older, 15,025 persons would initially be classified as being at intermediate risk for a cardiovascular event if conventional risk factors alone were used to calculate risk. Assuming that statin therapy would be initiated in accordance with Adult Treatment Panel III guidelines (i.e., for persons with a predicted risk of ≥20% and for those with certain other risk factors, such as diabetes, irrespective of their 10-year predicted risk), additional targeted assessment of CRP or fibrinogen levels in the 13,199 remaining participants at intermediate risk could help prevent approximately 30 additional cardiovascular events over the course of 10 years. CONCLUSIONS: In a study of people without known cardiovascular disease, we estimated that under current treatment guidelines, assessment of the CRP or fibrinogen level in people at intermediate risk for a cardiovascular event could help prevent one additional event over a period of 10 years for every 400 to 500 people screened. (Funded by the British Heart Foundation and others.).

Normal levels of inflammatory markers in treated patients with familial hypercholesterolaemia: a cross-sectional study.

OBJECTIVE: To assess the relationship of levels of inflammatory risk markers to presence of clinical coronary artery disease (CAD) in patients with treated heterozygous familial hypercholesterolaemia. DESIGN: A cross-sectional study of patients on the Simon Broome Familial Hyperlipidaemia Register. SETTING: Six hospital outpatient clinics in the UK. PARTICIPANTS: A total of 211 men and 199 women with heterozygous familial hypercholesterolaemia. MAIN OUTCOME MEASURES: Analysis of conventional risk factors and concentrations of high-sensitivity C-reactive protein (hsCRP), lipoprotein(a), serum intercellular adhesion molecule (sICAM), interleukin-6 (IL-6) and lipoprotein-associated phospholipase A2 (LpPLA2) mass. RESULTS: CAD was present in 104 men and in 55 women; the mean ages of onset were 43.1 and 46.5 years, respectively. On univariate analysis there was a positive relationship of CAD with age, male sex, smoking, IL-6 and sICAM, and an inverse relationship with low-density lipoprotein (LDL) and LpPLA2. On multivariate analysis, age, smoking, low LDL and low LpPLA2 were associated with CAD. When LpPLA2 values were adjusted for apoB and aspirin usage, there was no significant difference between those with and without CAD. Only age and smoking were independently associated with CAD in men, and IL-6 and lipoprotein(a) in women. CONCLUSIONS: Although on univariate analysis inflammatory marker levels were associated with CAD in these patients, the majority of the associations, including that for hsCRP, disappeared when corrected for smoking and apoB. This may be because atherosclerotic plaques in these statin-treated patients were quiescent or an effect of aspirin usage. In this observational study newer risk markers were not usefully associated with the presence or absence of symptomatic CAD.

Preliminary post-prandial studies of Burmese cats with elevated triglyceride concentrations and/or presumed lipid aqueous.

A proportion of Burmese cats in Australia have an exaggerated post-prandial triglyceride (TG) response after an oral fat tolerance test (OFTT). The aim of this study was to determine (a) whether Burmese cats with presumed lipid aqueous (PLA) had exaggerated post-prandial triglyceridaemia, (b) if Burmese cats with exaggerated post-prandial triglyceridaemia ('affected' cats) had decreased lipoprotein lipase (LPL) activity and (c) whether affected cats were more insulin resistant than normal Burmese cats. Of cats with a history of PLA, 4/5 were shown to be lipid intolerant (4h TG>4.5mmol/l). Four affected Burmese cats were age, gender and body condition matched to four normal Burmese cats. Serum TG, insulin, non-esterified fatty acids (NEFA), lipoprotein and apolipoprotein concentrations were determined 2 weeks after commencing a standardised high-protein diet, with an OFTT performed 4 weeks later. Affected Burmese cats did not have significantly different fasting insulin, fructosamine, NEFA, apolipoprotein or lipoprotein concentrations compared to control cats. During the OFTT, affected cats had significantly higher 4h and 6h serum TG and NEFA concentrations than normal cats. There was a trend for lower LPL activity, higher insulin concentrations (at 4 and 6h) and higher insulin area under the curve (AUC) during the OFTT in affected Burmese cats compared to controls, although these results failed to reach significance, probably due to the small number of cats studied. Further investigations using larger numbers of cats should focus on reduced LPL activity and insulin resistance as potential causes of delayed TG clearance.

Presence of free radicals in intracameral agents commonly used during cataract surgery.

BACKGROUND: Free radicals are known to cause cellular damage and are present in ophthalmic preparations. Corneal defence mechanisms are bypassed in intra-ocular surgery. We evaluated commonly used intracameral agents to ascertain the presence of free radicals and investigate the possibility of anterior segment and endothelial toxicity. METHODS: Samples of 19 commonly used intracameral preparations were analysed for total free radical presence on an Instrument Laboratory IL600 using a Randox Kit for Total Antioxidant Status (RANDOX Laboratories Ltd, Crumlin, UK). RESULTS: Free radical concentrations for the 19 intracameral agents ranged from 0 to 3.59 mmol/l, with median value of 0.34 mmol/l (mean value 0.933±1.19 mmol/l). Phenylephrine had the highest presence of free radicals, which were considerably higher than those for 0.5% hydrogen peroxide at all tested dilutions. Other notable results included cefuroxime (0.61 mmol/l), 2% undiluted lidocaine (0.34 mmol/l) and bevacizumab (0.59 mmol/l). CONCLUSION: The results indicate that free radicals are present in intracameral surgical agents and some are in the order of 0.5% hydrogen peroxide. The risks of endothelial damage must be considered when using multiple intracameral preparations in complicated cataract surgery. Free radicals in intracameral preparations may be a contributing cause in cases of toxic anterior segment syndrome.

Contribution of apolipoprotein E genotype and docosahexaenoic acid to the LDL-cholesterol response to fish oil.

OBJECTIVES: To investigate the impact of apolipoprotein E (apoE) genotype on the response of the plasma lipoprotein profile to eicosapentaenoic acid (EPA) versus docosahexaenoic acid (DHA) intervention in humans. METHODS AND RESULTS: 38 healthy normolipidaemic males, prospectively recruited on the basis of apoE genotype (n=20 E3/E3 and n=18 E3/E4), completed a double-blind placebo-controlled cross-over trial, consisting of 3 x 4 week intervention arms of either control oil, EPA-rich oil (ERO, 3.3g EPA/day) or DHA-rich oil (DRO, 3.7g DHA/day) in random order, separated by 10 week wash-out periods. A significant genotype-independent 28% and 19% reduction in plasma triglycerides in response to ERO and DRO was observed. For total cholesterol (TC), no significant treatment effects were evident; however a significant genotype by treatment interaction emerged (P=0.045), with a differential response to ERO and DRO in E4 carriers. Although the genotype x treatment interaction for LDL-cholesterol (P=0.089) did not reach significance, within DRO treatment analysis indicated a 10% increase in LDL (P=0.029) in E4 carriers with a non-significant 4% reduction in E3/E3 individuals. A genotype-independent increase in LDL mass was observed following DRO intervention (P=0.018). Competitive uptake studies in HepG2 cells using plasma very low density lipoproteins (VLDL) from the human trial, indicated that following DRO treatment, VLDL(2) fractions obtained from E3/E4 individuals resulted in a significant 32% (P=0.002) reduction in LDL uptake relative to the control. CONCLUSIONS: High dose DHA supplementation is associated with increases in total cholesterol in E4 carriers, which appears to be due to an increase in LDL-C and may in part negate the cardioprotective action of DHA in this population subgroup.

Lipoprotein-associated phospholipase A2 decreases oxidized lipoprotein cellular association by human macrophages and hepatocytes.

We investigated whether the presence of endogenous or exogenous lipoprotein-associated phospholipase A2 (Lp-PLA2) can modify the cellular association of oxidized low density lipoprotein (oxLDL) and oxidized lipoprotein(a) (oxLp(a)) by human monocyte-derived macrophages (MDM) and hepatocytes (HepG2). Purified recombinant Lp-PLA2 was used as a source of exogenous enzyme whereas Pefabloc (serine esterase inhibitor) was used to inhibit the endogenous Lp-PLA2 activity associated with isolated lipoproteins. Cellular association studies were performed with DiI-labeled oxLDL or oxLp(a) and human monocyte-derived macrophages and HepG2 cells. Active Lp-PLA2 decreased the cellular association of oxLDL and oxLp(a) in macrophages and HepG2 cells by approximately 30-40%, whereas the inactive enzyme did not significantly change oxidized lipoprotein cellular association by either cell type. OxLDL pretreated by Pefabloc increased oxLDL cellular association by MDM and HepG2 cells compared to untreated oxLDL. Therefore, unlike some lipases, Lp-PLA2 did not appear to have any catalytic independent function in oxLDL cellular association. To assess whether the reduced cellular association mediated by Lp-PLA2 was due to the hydrolysis of oxidized phosphatidylcholine (oxPC), we measured the concentration of lysophosphatidylcholine (lysoPC) in lipoprotein fractions after Lp-PLA2 treatment. LysoPC was increased by 20% (0.4 microM) and 87% (0.7 microM) by active Lp-PLA2 compared to inactive Lp-PLA2 for oxLDL and Lp(a), respectively. LysoPC at higher concentration dose-dependently increased the cellular association of oxLDL and oxLp(a) in MDM and HepG2 cells. We conclude that Lp-PLA2 mediates a decrease in oxidized lipoprotein cellular association in human macrophages and HepG2 cells by reducing the concentration of oxPC within these lipoproteins.

Apolipoprotein e genotype, plasma cholesterol, and cancer: a Mendelian randomization study.

Observational studies have shown an association between low plasma cholesterol levels and increased risk of cancer, whereas most randomized clinical trials involving cholesterol-lowering medications have not shown this association. Between 1997 and 2002, the authors assessed the association between plasma cholesterol levels and cancer risk, free from confounding and reverse causality, in a Mendelian randomization study using apolipoprotein E (ApoE) genotype. ApoE genotype, plasma cholesterol levels, and cancer incidence and mortality were measured during a 3-year follow-up period among 2,913 participants in the Prospective Study of Pravastatin in the Elderly at Risk. Subjects within the lowest third of plasma cholesterol level at baseline had increased risks of cancer incidence (hazard ratio (HR) = 1.90, 95% confidence interval (CI): 1.34, 2.70) and cancer mortality (HR = 2.03, 95% CI: 1.23, 3.34) relative to subjects within the highest third of plasma cholesterol. However, carriers of the ApoE2 genotype (n = 332), who had 9% lower plasma cholesterol levels than carriers of the ApoE4 genotype (n = 635), did not have increased risk of cancer incidence (HR = 0.86, 95% CI: 0.50, 1.47) or cancer mortality (HR = 0.70, 95% CI: 0.30, 1.60) compared with ApoE4 carriers. These findings suggest that low cholesterol levels are not causally related to increased cancer risk.

Identification of potential serum biomarkers of inflammation and lipid modulation that are altered by fish oil supplementation in healthy volunteers.

Long chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) lower risk of coronary heart disease (CHD), but mechanisms are not well understood. We used proteomics to identify human serum proteins that are altered by n-3 LCPUFA. Such proteins could identify pathways whereby they affect CHD. Eighty-one healthy volunteers entered a double blind randomised trial to receive 3.5 g of fish oil or 3.5 g of high oleic sunflower oil daily. Serum was collected before and after 6 wk of intervention. Serum was analysed by proteomics using 2-DE. Proteins that were differentially regulated were identified by MS. We also analysed serum apolipoprotein A1 (apo A1), high-density lipoprotein (HDL) particle size and haptoglobin. Serum levels of apo A1, apo L1, zinc-alpha-2-glycoprotein, haptoglobin precursor, alpha-1-antitrypsin precursor, antithrombin III-like protein, serum amyloid P component and haemopexin were significantly downregulated (all p<0.05) by fish oil compared with high oleic sunflower oil supplementation. Fish oil supplementation caused a significant shift towards the larger, more cholesterol-rich HDL(2) particle. The alterations in serum proteins and HDL size imply that fish oil activates anti-inflammatory and lipid modulating mechanisms believed to impede the early onset of CHD. These proteins are potential diagnostic biomarkers to assess the mechanisms whereby fish oil protects against CHD in humans.

Longitudinal assessment of maternal endothelial function and markers of inflammation and placental function throughout pregnancy in lean and obese mothers.

BACKGROUND: Obesity in pregnancy is increasing and is a risk factor for metabolic pathology such as preeclampsia. In the nonpregnant, obesity is associated with dyslipidemia, vascular dysfunction, and low-grade chronic inflammation. AIM: Our aim was to measure microvascular endothelial function in lean and obese pregnant women at intervals throughout their pregnancies and at 4 months after delivery. Plasma markers of endothelial function, inflammation, and placental function and their association with microvascular function were also assessed. METHODS: Women in the 1st trimester of pregnancy were recruited, 30 with a body mass index (BMI) less than 30 kg/m(2) and 30 with a BMI more than or equal to 30 kg/m(2) matched for age, parity, and smoking status. In vivo endothelial-dependent and -independent microvascular function was measured using laser Doppler imaging in the 1st, 2nd, and 3rd trimesters of pregnancy and at 4 months postnatal. Plasma markers of endothelial activation [soluble intercellular cell adhesion molecule-1 (sVCAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), von Willebrand factor (vWF), and plasminogen activator inhibitor (PAI)-1], inflammation (IL-6, TNFalpha, C-reactive protein, and IL-10), and placental function (PAI-1/PAI-2 ratio) were also assessed at each time point. RESULTS: The pattern of improving endothelial function during pregnancy was the same for lean and obese, but endothelial-dependent vasodilation was significantly lower (P < 0.05) in the obese women at each trimester (51, 41, and 39%, respectively). In the postpartum period, the improvement in endothelial-dependent vasodilation persisted in the lean women but declined to near 1st trimester levels in the obese (lean/obese difference, 115%; P < 0.01). There was a small but significant difference in endothelial-independent vasodilation between the two groups, lean response being greater than obese (P = 0.021), and response declined in both groups in the postpartum period. In multivariate analysis, time of sampling had the most impact on endothelial-independent function [18.5% (adjusted sum of squares expressed as a percentage of total means squared), P < 0.001 for sodium nitroprusside response; 9.8%, P < 0.001 for acetylcholine response], and obesity had the most impact on endothelial-dependent microvascular function (1.7%, P = 0.046 for sodium nitroprusside response; 19.3%, P < 0.001 for acetylcholine response). Time of sampling (11.2%, P < 0.001), IL-6 (4.0%, P = 0.002), and IL-10 (2.4%, P = 0.018) were significant independent contributors to variation in endothelial-dependent microvascular function. When obesity was entered into the model, the association with IL-6 and IL-10 was no longer significant, and obesity explained 6.8% (P < 0.001) of the variability in endothelial-dependent microvascular function. In the 1st trimester, obese women had a significantly higher PAI-1/PAI-2 ratio [obese median (interquartile range), 0.87 (0.54-1.21) vs. lean 0.30 (0.21-0.47), P < 0.001), reflecting the lower PAI-2 levels in obese pregnant women. In a multivariate analysis, 1st trimester BMI (7.6%, P = 0.012), IL-10 (8.2%, P < 0.001), and sVCAM-1 (0.73%, P = 0.007) contributed to the 1st trimester PAI-1/PAI-2 ratio. CONCLUSION: Obese mothers have a lower endothelium-dependent and -independent vasodilation when compared with lean counterparts. There was a higher PAI-1/ PAI-2 ratio in the 1st trimester in obese women, which improved later in pregnancy. Obese pregnancy is associated with chronic preexisting endothelial activation and impairment of endothelial function secondary to increased production of inflammatory T-helper cells-2 cytokines.

A common variant in the glutathione S transferase gene is associated with elevated markers of inflammation and lipid peroxidation in subjects with diabetes mellitus.

INTRODUCTION: Glutathione S transferases (GST) are enzymes responsible for the metabolism of numerous xenobiotics and play a major cellular antioxidant role. Our aim was firstly, to examine the association between the GST M1/GST mu-1 (GSTM1) and GST T1/GST theta-1 (GSTT1) gene variants with markers of oxidative stress and inflammation in diabetic patients, and secondly to examine the association and potential interaction between these variants and cigarette smoking. METHODS: Seven hundred and seventy-three Caucasian subjects with diabetes and 2592 Caucasian non-diabetic subjects were successfully genotyped. Plasma total antioxidant status, C-reactive protein (CRP), oxidized-LDL (Ox-LDL) and LDL-mean/peak particle diameter were recorded in the diabetes sample. RESULTS: No association was seen between genotype and cardiovascular disease (CVD) risk. In the diabetic subjects, GSTT1-1 compared to GSTT1-0 subjects had significantly higher CRP (p=0.001), Ox-LDL (p=0.004) and smaller LDL particles (p=0.01). In subjects without CVD, there was a significant interaction between the GSTT1-1 variant and smoking in determining Ox-LDL (p=0.04). Furthermore, CVD risk was higher in smokers compared to non-smokers with GSTT1-1. No significant associations were observed by GSTM1. Within the non-diabetic sample, no association was observed between genotype and prospective coronary heart disease (CHD) risk. Of note, the frequency of the GSTT1-1 variant was significantly lower in the diabetes subjects compared to the non-diabetic sample (p=0.01). CONCLUSIONS: This study demonstrates an association between the GSTT1-1 variant and markers of inflammation and lipid peroxidation. Furthermore this variant interacts with smoking to increase lipid peroxidation.

Fluctuations in C-reactive protein concentration and neutrophil activation during normal human pregnancy.

OBJECTIVES: To clarify the changes in serum C-reactive protein (CRP) levels and in the neutrophil activation state during normal human pregnancy. MATERIALS AND METHODS: A longitudinal study (n=23) was performed during the three trimesters of pregnancy; a group of non-pregnant women (n=24) was used as control. Total and differential leukocyte count, serum concentration of CRP and plasma levels of granulocyte-macrophage colony stimulating factor (GM-CSF) and of lactoferrin and elastase (two indirect markers of neutrophil activation) were measured. RESULTS: Pregnancy imposed an inflammatory response in the mother, observed by the significant increment in total white blood cell (WBC) and neutrophil counts and in the circulating levels of CRP, GM-CSF and lactoferrin, in all trimesters of gestation compared with non-pregnant controls. Plasma elastase concentration was also significantly higher in pregnant women, but only in the first trimester of gestation. Regarding the ratios of lactoferrin and elastase per neutrophil, they were significantly lower in pregnant women (all trimesters). During gestation, WBC and neutrophil count increased significantly from the first to the second trimester and remained high in the third period. In contrast, the ratios of lactoferrin and elastase per neutrophil decreased significantly from the first to the second trimester, remaining low in the last trimester. Concerning CRP levels, no consistent changes were observed throughout gestation; 12 cases (52.2%) presented fluctuations, whereas 7 (30.4%) showed progressive reductions and 4 (17.4%) progressive increments throughout pregnancy. CONCLUSIONS: Changes in CRP levels vary in a wide manner between subjects along pregnancy, even though median values are consistently elevated throughout pregnancy. Moreover, circulating levels of neutrophil-activation products are higher in normal human gestation.

Physical activity, dietary intake and metabolic risk factors in non-diabetic daughters of patients with type II diabetes.

BACKGROUND: It has been reported that the offspring of patients with type II diabetes have an adverse metabolic risk profile. This study aimed to investigate the impact of habitual physical activity and diet on metabolic risk factors in the daughters of patients with type II diabetes and control subjects. METHODS: Thirty-nine offspring and 39 age- and sex-matched controls completed physical activity and food intake diaries, during the week preceding a fasting blood sample. RESULTS: The offspring had higher body mass index, percentage body fat, and waist circumference than the control subjects (all P < 0.01). Fasting glucose and insulin, and insulin sensitivity estimated by the homeostasis model assessment (HOMA(IR)) method, were also higher in the offspring group (all P < 0.01). Daily energy expenditure was lower (P < 0.0001) in the offspring than control group. Dietary profile was not different between the groups. Daily energy expenditure was significantly correlated with waist circumference, fasting insulin, and HOMA(IR) (all P < 0.05) in offspring but not controls. CONCLUSIONS: Offspring had a less favourable physical and metabolic profile and were less physically active than control subjects. In offspring, central adiposity and metabolic risk factors were influenced by habitual physical activity to a greater degree than in control subjects.

Effects of prior moderate exercise on postprandial metabolism and vascular function in lean and centrally obese men.

OBJECTIVES: We investigated whether a session of prior exercise could ameliorate postprandial endothelial dysfunction. BACKGROUND: Endothelial function is impaired after fat ingestion, and this may be related to rises in triglyceride concentrations. Exercise reduces postprandial triglyceride concentrations. METHODS: Ten lean (waist <90 cm) and 10 centrally obese (waist >100 cm) middle-aged men each underwent two oral fat tolerance tests (blood taken fasting and for 8 h after a high-fat meal containing 80 g fat and 70 g carbohydrate). On the afternoon before one test, subjects performed a 90-min treadmill walk (exercise); no exercise was performed before the control test. Endothelium-dependent and -independent microvascular function was assessed using laser Doppler imaging in the fasted state and at two hourly intervals during the 8-h postprandial period. RESULTS: Exercise reduced both fasting and postprandial triglyceride concentrations by 25% in both the lean and centrally obese groups (p < 0.0005). For all subjects taken together, exercise improved fasting endothelium-dependent function by 25% (p < 0.05), and, although there was a significant postprandial decrease in both endothelium-dependent and -independent function in both the control and exercise trials (p < 0.01), postprandial endothelium-dependent and -independent function were 15% and 20% higher, respectively, in the exercise trial than the control trial (both p < 0.05). CONCLUSIONS: A session of prior exercise improves fasting and postprandial vascular function in middle-aged men. This may be one mechanism by which exercise influences cardiovascular risk.

LDL size, total antioxidant status and oxidised LDL in normal human pregnancy: a longitudinal study.

The aim of our work was to evaluate changes in levels of oxidised low-density lipoprotein (Ox-LDL) during pregnancy and how they correlate with changes in LDL size and serum total antioxidant status (TAS). LDL peak and mean particle diameter (LDL-PPD and LDL-MPD, respectively) and the relative proportion of 3 LDL subfractions were quantified. We evaluated plasma levels of Ox-LDL and serum levels of TAS, total cholesterol (Chol), triglycerides (TG), apolipoprotein A-I (apo A-I), apolipoprotein B (apo B), HDL-cholesterol (HDLc) and LDL-cholesterol (LDLc). A longitudinal study was performed in the three trimesters (T1-T3) of pregnancy in normal pregnant women (n = 23) and a non-pregnant group (n = 18) was used as control. TG levels were significantly elevated whereas LDL-MPD and LDL-PPD were significantly reduced in T1 compared to controls. Ox-LDL, TG, Chol, apo B and LDLc rose markedly throughout pregnancy with significant changes between each trimester; LDL-PPD, LDL-MPD and TAS levels decreased significantly from T1 to T3. Changes in LDL size and in Ox-LDL and TAS levels were more pronounced between T1 and T2 than between T2 and T3. HDLc and apo A-I reached peak concentration in T2 but decreased in T3. TG concentrations correlated inversely with LDL size and positively with Ox-LDL; Ox-LDL was positively and strongly correlated with LDLc. Moreover, relative changes in the levels of Ox-LDL correlated inversely with relative changes in LDL size and TAS between trimesters. In conclusion, during human gestation the change in LDL profile towards smaller species and the decrease in serum TAS are closely associated with increased levels of Ox-LDL. The exact physiological role of the increments in Ox-LDL during pregnancy remains to be clarified.