Josep Redon

Increased oxidative stress levels and normal antioxidant enzyme activity in circulating mononuclear cells from patients of familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a clinical condition with high risk for developing atherosclerosis. Increased oxidative stress (OS) and FH have been related to atherosclerosis, but no data are available on levels of OS and antioxidant enzyme activity in circulating mononuclear cells (CMCs) from FH patients. Circulating mononuclear cells are important mediators in atherosclerosis development, and chronically increased blood OS present in FH can induce modification in CMC activity. The objective of the study was to analyze the OS levels in CMCs from FH patients and controls. We have selected 30 nonrelated FH index patients and 30 normoglycemic and normocholesterolemic controls matched by age, sex, body mass index, abdominal circumference, and homeostasis model assessment index. Production of free radicals was analyzed by measurement of xanthine oxidase activity in plasma, reduced and oxidized glutathione (GSH and GSSG, respectively), and malonyldialdehyde in levels CMCs. Antioxidant status was analyzed by measuring antioxidant enzyme activity as superoxide dismutase, catalase, and glutathione peroxidase. We have found that FH patients showed significantly higher xanthine oxidase and malonyldialdehyde enzyme activities, as well as increased GSSG and lower GSH values resulting in a higher GSSG/GSH ratio. These data indicate a higher free radical production in plasma and increased OS levels in CMCs from patients than from controls. No significant differences were found in superoxide dismutase, catalase, and glutathione peroxidase activities between both groups. These data show an important alteration of OS regulation in FH and the absence of antioxidant response in CMCs mediated by some of the major antioxidant enzymes.

Polymorphisms of the UCP2 gene are associated with body fat distribution and risk of abdominal obesity in Spanish population.

Eur J Clin Invest 2011

Association of selected ABC gene family single nucleotide polymorphisms with postprandial lipoproteins: Results from the population-based Hortega study

The aim of the study was to determine the influence of twenty single nucleotide polymorphisms (SNPs) of the ABCA1, ABCG1, ABCG5 and ABCG8 genes on the plasmatic concentrations of total cholesterol (TC), HDL and LDL cholesterol (HDLc, LDLc) in the postprandial state with a representative Spanish Caucasian population (1473 individuals, 50.0% women, ages ranging 21-85 years). In men, subjects with the AA genotype of the ABCA1 rs2230806 (R219K) polymorphism were associated with increased plasma LDLc levels, while the ABCA1 haplotype, which included the rs2230806 A allele, was associated with higher TC and LDLc plasma concentrations. In women, significant relationships were found between rs1893590 polymorphisms (ABCG1 gene) and HDLc plasma concentrations (subjects with the AA genotype had lower HDLc levels). For the ABCG8 gene, the rs4148211 polymorphism was associated with higher plasma TC and LDLc concentrations in the total population. Moreover, an ABCG5-G8 haplotype, which included the rs6544718 T allele, was associated with higher HDLc plasma concentrations in women. In conclusion, different SNPs of the ABCA1, ABCG1 and ABCG5-ABCG8 genes were associated, some under gender-specific analysis, with variations in the plasma lipid levels under postprandial conditions in a representative Spanish population.

Dietary polyunsaturated fatty acids may increase plasma LDL-cholesterol and plasma cholesterol concentrations in carriers of an ABCG1 gene single nucleotide polymorphism: Study in two Spanish populations

BACKGROUNDnABCG1 mediates cellular cholesterol transport, but there is very little known about the influence of ABCG1 polymorphisms on human plasma lipoprotein cholesterol concentrations or on the interactions of these polymorphisms with diet.nnnOBJECTIVEnOur objective was to investigate whether interactions between PUFA intake and ABCG1 polymorphisms modulate associations with plasma total cholesterol (TC), LDL- and HDL-cholesterol in two Spanish populations.nnnMETHODSnWe grounded our investigation on two general population-based studies: the Hortega study (population A) and the Pizarra study (population B). Participants included 1178 individuals (50.0% women, age range 21-85 years) and 763 individuals (66% women, age range 23-73 years) from populations A and B, respectively, without lipid lowering drugs. Subjects were genotyped for ABCG1 variants. Biochemical measurements were taken by standard procedures. Dietary intakes were estimated with a validated questionnaire.nnnRESULTSnIn population A, the A allele homozygotes of SNP rs4148102 had higher TC and LDLc concentrations in subjects on a high PUFA diet than did the carriers of the G allele (242.1 ± 38.9 vs. 198.0 ± 36.0mg/dL, p = 0.003, and 149.8 ± 37.9 vs. 111.4 ± 32.1mg/dL, p = 0.005, respectively), and significant gene-diet interactions were observed (p=0.020 and p = 0.013, respectively). In population B, similar differences in TC and LDLc concentrations were also found in association with this SNP under a high PUFA diet (253.2±24.9 vs. 197.7 ± 39.9 mg/dL, p = 0.009, and 171.8 ± 20.5 vs. 120.4 ± 34.2mg/dL, p = 0.004, respectively), but the gene-diet interactions observed were not significant (p = 0.379 and p = 0.422, respectively). In the pooled populations, differences in the TC and LDLc concentrations increased (246.8 ± 32.9 vs. 198.0 ± 37.5, p = 6 × 10(-5), and 159.0±32.6 vs. 114.3 ± 33.1, p = 3 × 10(-5), respectively), and significant gene-diet interactions were maintained (p = 0.006 and p = 0.003, respectively).nnnCONCLUSIONnIn two Spanish populations, the ABCG1 polymorphism rs4148102 was associated with variations in plasma lipoprotein cholesterol concentrations in subjects with high PUFA intakes. Carriers of the AA genotype consuming high PUFA diet showed higher plasma LDLc concentrations.

[OP.3C.05] LDL-PARTICLES COMPOSITION AND INCIDENT CARDIOVASCULAR DISEASE IN A SOUTH-EUROPEAN POPULATION: THE HORTEGA-LIPOSCALE STUDY

Objective: The use of LDL-cholesterin particles (LDL-p) for cardiovascular risk prediction has been tested in high risk populations. The objective of this study was to evaluate the association of LDL-p and LDL-p composition with incident cardiovascular disease in adults participating in the Hortega Follow-up Study, a cohort study representative of a general population from Spain. Figure. No caption available. Design and method: “Standard” lipid levels (plasma total cholesterol, HDL-cholesterol, and triglyceride concentrations) were determined using a Hitachi 917 analyzer. The number and size of lipid particles were measured by nuclear magnetic resonance using LIPOSCALE algorithm (Biosfer Teslab, Reus, Spain). The association of lipid levels and LDL-particles composition with incident cardiovascular disease was assessed. Results: A total of 1162 subjects (49% male, mean age 49.7 years) was included into the study. LDL-p distribution was as followed: Small LDL-p was predominant (40–70%), followed by Medium LDL-p (20–40%) and Large LDL-p (10–20%). During a mean-follow up of 12.4u200a±u200a3.3 years, a total of 159 CV events occurred. LDL particle size was related to all events when traditional cardiovascular risk factors were controlled for. Medium LDL-p, but not Small LDL-p, increased the risk of CHD and stroke in all statistical models. The relevance of Medium LDL-p was further evaluated in a compositional analysis using a leave-one-out approach. The highest risks were observed for LDL-p and CHD when the proportions of Medium and Small LDL-p were entered simultaneously into the model, which reflects an increase in the proportion of Medium LDL-p and Small LDL-p by a corresponding decrease in the proportion of Large LDL-p, respectively. That shift from Large to Medium and Small LDL-p proportions was associated with an increase in risk for CHD of 70% and 46%, respectively (figure 1). Conclusions: In a representative sample of the general population from Spain, NMR-measured LDL-particle size and composition were associated with cardiovascular outcomes. An increase in the proportion of Medium LDL-particles and Small LDL-particles by a corresponding decrease in the proportion of Large LDL-p was strongly associated with CHD. Further research is needed to elucidate the causal pathways underlying these associations.

[OP.7B.03] BLOOD PRESSURE AND OBESITY METABOLOMIC STRATIFIED ANALYSIS OF A SPANISH GENERAL POPULATION.

Objective: We aimed to screen metabolomes of combined hypertension and obesity in a Spanish general population cohort to identify differential metabolic profiles for better risk estimation and patient stratification. Design and method: We measured blood serum high resolution NMR spectra from hypertensive subjects with (HT_OB, nu200a=u200a356) or without (HT_noOB, nu200a=u200a280) abdominal obesity and normotensive subjects with (noHT_OB, nu200a=u200a291) or without (noHT_noOB, nu200a=u200a555) abdominal obesity for detecting metabolic cores specifically affected in the different groups. We performed four different projection to latent structures for discriminant analysis (PLS-DA) for binary comparison of the different groups (HT_OB vs HT_noOB, noHT_OB vs noHT_noOB, HT_OB vs noHT_OB and nHT_noOB vs HT_noOB). The models were cross-validated using the Venetian Blinds approach (20 technical replicates). Statistical analysis was performed using SPSS, in-house MATLAB scripts and the PLS Toolbox statistical multivariate analysis library. Results: Our approach revealed a common set of metabolites associated to hypertension and obesity both in combination and separately. Total fatty acids, glucose and valine moieties contributed to all the PLS-DA models with a variable importance in projection (VIP) score greater than 1. The models for discrimination of hypertension included additional contribution of lactate, 3-hydroxyvalerate and LDL/VLDL regardless of abdominal obesity. Cholesterol contributed to all the models with the exception of hypertension in a non-obese context (HT_noOB vs noHT_noOB). The metabolic profiles also revealed associations with distinct short chain fatty acids (SCFAs) in all the models. Tryptophan was associated in a specific manner with the discrimination of hypertension in obese subjects. GlycA moieties, recently associated to systemic inflammation, only contributed to the discrimination of obesity in no hypertensive patients. Conclusions: Our stratified metabolomic analysis of hypertension and obesity using chemometric techniques reveals common metabolic alterations previously associated to metabolic wellness. The specific models demonstrate that the discriminant value of the different potential biomarkers highly depend on previous health states. The involvement of SCFA and tryptophan in the models also suggests some role of the brain-gut-microbiome axis in the interaction between obesity and hypertension.

6C.04: INTEGRATED SNP ANALYSIS AND METABOLOMIC PROFILES OF METABOLIC SYNDROME.

Objective: Metabolic syndrome (MS) has become a health and financial burden worldwide. Susceptibility of genetically determined metabotype of MS has not yet been investigated. We aimed to identify a distinctive metabolic profile of blood serum which might correlates to the early detection of the development of MS associated to genetic polymorphism. Design and method: We applied high resolution NMR spectroscopy to profile blood serum from patients without MS (nu200a=u200a945) or with (nu200a=u200a291). Principal component analysis (PCA) and projection to latent structures for discriminant analysis (PLS-DA) were applied to NMR spectral datasets. Results were cross-validated using the Venetian Blinds approach. Additionally, five SNPs previously associated with MS were genotyped with SNPlex and tested for associations between the metabolic profiles and the genetic variants. Statistical analysis was performed using in-house MATLAB scripts and the PLS Toolbox statistical multivariate analysis library. Results: Our analysis provided a PLS-DA Metabolic Syndrome discrimination model based on NMR metabolic profile (AUCu200a=u200a0.86) with 84% of sensitivity and 72% specificity. The model identified 11 metabolites differentially regulated in patients with MS. Among others, fatty acids, glucose, alanine, hydroxyisovalerate, acetone, trimethylamine, 2-phenylpropionate, isobutyrate and valine, significantly contributed to the model. The combined analysis of metabolomics and SNP data revealed an association between the metabolic profile of MS and genes polymorphism involved in the adiposity regulation and fatty acids metabolism: rs2272903_TT (TFAP2B), rs3803_TT (GATA2), rs174589_CC (FADS2) and rs174577_AA (FADS2). In addition, individuals with the rs2272903-TT genotype seem to develop MS earlier than general population. Conclusions: Our study provides new insights on the metabolic alterations associated with a MS high-risk genotype. These results could help in future development of risk assessment and predictive models for subclinical cardiovascular disease.