Sophie Visvikis-siest - Academia.edu (original) (raw)

Papers by Sophie Visvikis-siest

PLOS ONE, Jan 4, 2012

African Americans are disproportionately affected by type 2 diabetes (T2DM) yet few studies have ... more African Americans are disproportionately affected by type 2 diabetes (T2DM) yet few studies have examined T2DM using genome-wide association approaches in this ethnicity. The aim of this study was to identify genes associated with T2DM in the African American population. We performed a Genome Wide Association Study (GWAS) using the Affymetrix 6.0 array in 965 African-American cases with T2DM and end-stage renal disease (T2DM-ESRD) and 1029 population-based controls. The most significant SNPs (n = 550 independent loci) were genotyped in a replication cohort and 122 SNPs (n = 98 independent loci) were further tested through genotyping three additional validation cohorts followed by meta-analysis in all five cohorts totaling 3,132 cases and 3,317 controls. Twelve SNPs had evidence of association in the GWAS (P,0.0071), were directionally consistent in the Replication cohort and were associated with T2DM in subjects without nephropathy (P,0.05). Meta-analysis in all cases and controls revealed a single SNP reaching genome-wide significance (P,2.5610 28). SNP rs7560163 (P = 7.0610 29 , OR (95% CI) = 0.75 (0.67-0.84)) is located intergenically between RND3 and RBM43. Four additional loci (rs7542900, rs4659485, rs2722769 and rs7107217) were associated with T2DM (P,0.05) and reached more nominal levels of significance (P,2.5610 25) in the overall analysis and may represent novel loci that contribute to T2DM. We have identified novel T2DM-susceptibility variants in the African-American population. Notably, T2DM risk was associated with the major allele and implies an interesting genetic architecture in this population. These results suggest that multiple loci underlie T2DM susceptibility in the African-American population and that these loci are distinct from those identified in other ethnic populations.

Archives of Medical Research, Jul 1, 2010

Gene targeting approaches have suggested that the angiotensin II type 1 receptor (AT1R) is involv... more Gene targeting approaches have suggested that the angiotensin II type 1 receptor (AT1R) is involved in blood pressure (BP) regulation and modulation of the effect of angiotensin II. The A1166C polymorphism of the AT1 receptor gene (AT1R/A1166C) is associated with hypertension in Caucasians, but not in Japanese. The goal of this study, the Ohasama Study, was to examine the association between AT1R/A1166C and hypertension, especially home BP, in the Japanese general population. The Ohasama Study was a cohort study based on Japanese rural residents of Ohasama Town in the northern part of Japan. Subjects who gave informed consent to the study protocol and genetic analysis were recruited. Home BP was measured twice in the morning within 1 h of waking up and in the evening just before going to bed. The TaqMan polimerase chain reaction (PCR) method clearly determined AT1R/A1166C genotypes (n 1,207). The genotype distribution of AT1R/A1166C was as follows: AA 84%; AC 15%; CC 1%. There was almost no difference in baseline characteristics among the AT1R genotypes (AA, AC, CC). In the subjects not receiving antihypertensive medication (n 817), both casual BP and home BP were not different among the AT1R genotypes after adjusting for confounding factors (age, sex, body mass index, current smoking habit and current alcohol consumption). The frequency of hypertension showed no difference among AT1R genotypes after adjusting for confounding factors, though the AC and CC genotypes were more frequent in hypertensives than in normotensives. Our data suggested that the AT1R/A1166C polymorphism is not a major genetic predisposing factor for hypertension in Japanese.

ABSTRACT Poster. Colloque avec actes et comité de lecture. nationale.

Clinical Biochemistry, Sep 1, 2011

Nutrients, Apr 13, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

Clinical Chemistry and Laboratory Medicine, 1998

The influence of apolipoprotein E polymorphism and apoE level on serum lipids and apolipoproteins... more The influence of apolipoprotein E polymorphism and apoE level on serum lipids and apolipoproteins was investigated in 71 healthy people and 43 patients with coronary artery disease from Shanghai. The frequency of apoE alleles was 0.06 for ε2, 0.86 for ε3, and 0.07 for ε4 in the healthy group, and 0.14 for ε2, 0.77 for ε3, and 0.09 for ε4 in the coronary artery disease group. There was no significant difference in the frequency of apoE alleles between these two groups. Serum levels of triglyceride and apo AI did not differ according to apoE genotypes, whereas serum level of apoB was significantly different according to apoE genotypes (p<0.05) both in healthy and coronary artery disease groups. However, in the healthy group, apo ε2 allele carriers had significantly higher level of apoE than apo ε3 and ε4 allele carriers (p<0.001) and apo ε4 allele carriers had significantly higher level of total cholesterol than apo ε3 and ε2 allele carriers. These were not observed in the coronary artery disease group. ApoE concentration was positively correlated with cholesterol, apoAI, and apoB levels in the control subjects and no significant correlation was observed with triglyceride level. In contrast, apoE level was positively related only to triglyceride level in the coronary artery disease group. In the control group, apoE genotypes and apoE level explained together 19.3 % and 26.6 % of the variability of apoB and cholesterol level, respectively, apoE polymorphism explained 23 % of the variability of apoE level and apoE level explained 13.2 % of the variability of apoAI level. In the coronary artery disease group, only apoE level explained 41.7 % of triglyceride variability. Finally we compared our results with those previously obtained in a French healthy population, the Stanislas cohort. Results suggested that there were some difference between the Chinese control and the French subjects.

European journal of cardiovascular prevention & rehabilitation, Jun 1, 1999

, uzanna ans, iviane icau , Luis Masana'', Sophie Visvikis", Christian Gerdes' and Lars Wilhelmse... more , uzanna ans, iviane icau , Luis Masana'', Sophie Visvikis", Christian Gerdes' and Lars Wilhelmsen 9 on behalf of the European Atherosclerosis Research Studies groups Background Lifestyle, genetic, bioclinical and biochemical factors of European university students aged 18-26 years, with and without documented paternal histories of premature coronary heart disease, have been compared in the European Atherosclerosis Research Studies (EARS) I and II. Objective To highlight consistencies and inconsistencies between findings in the two studies. Methods All measurements were made according to strict protocols, by trained technicians using validated methods. The results for men in EARS I are compared with those from EARS II which was confined to men. Results In both studies we found no differences between cases and controls in lifestyle factors and bioclinical factors except that controls were taller. We found inconsistent differences between obesity indices and antecedents of arterial hypertension. In both studies we found consistent differences between cases and controls in levels of total cholesterol and apolipoprotein B, both levels being higher in cases. The lack of any difference between levels of high-density lipoprotein cholesterol and apolipoprotein A 1 was also found consistently. Inconsistent differences were found for levels of triglycerides and apolipoprotein E. For most of the candidate genes that were studied, no differences between cases and controls were found, but different polymorphisms were associated with levels of lipids, apoproteins and fibrinogen independently of case-control status. Some of these associations were potentiated by lifestyle factors. The interaction between genetic and environmental factors is further illustrated with results from the association of apolipoprotein E polymorphism with the level of apolipoprotein B and a variety of other determinants of apolipoprotein B level. Conclusions In the EARS studies a documented family history of premature coronary heart disease was mainly expressed in terms of biochemical factors that are determined both by nature and by nurture.

Chemical & Pharmaceutical Bulletin, 2004

Intelligent Systems in Molecular Biology, Aug 1, 2002

Based on an application of symbolic data mining methods on a test database, we underline the role... more Based on an application of symbolic data mining methods on a test database, we underline the role played by the analyst in the knowledge discovery process. Encouraged by positive results, we plan to apply these methods on a large database for investigating the relationships between gene polymorphisms and cardiovascular diseases intermediate phenotypes.

Clinical Chemistry and Laboratory Medicine, 2007

British Journal of Nutrition, Dec 1, 2006

Although numerous environmental factors are documented to influence serum ascorbic concentrations... more Although numerous environmental factors are documented to influence serum ascorbic concentrations, little is known about the genetic versus environmental contributions to variation of this trait. The aim of this study was to estimate family correlation and, additive genetic heritability and household effects in a variance component analysis for serum ascorbic acid concentrations. In a sample of ninety French families, information was obtained regarding serum ascorbic acid concentrations, usual dietary intake, lifestyle, and other related covariates. Spouse, parent-offspring and offspring-offspring significant correlation coefficients for serum ascorbic acid concentrations, adjusted for age, cigarette consumption and oral contraceptive use, were 0•432, 0•298 and 0•485, respectively, and for adjusted values for additional diet covariates (vitamin C intake and fruit and vegetable consumption), were 0•362, 0•154 and 0•348, respectively. Variance component analysis for serum ascorbic concentrations showed no significant genetic contribution to variability of this trait. Conversely, household common environment accounted for 27•7 and 42•6 % in parents and offspring, respectively, after adjustment for age, cigarette consumption and oral contraceptive use. After adjustment for the two additional diet covariates (vitamin C intake and fruit and vegetable consumption) household common variance decreased to 13•6 and 30•5 % in parents and offspring, respectively. These results show that serum ascorbic acid concentrations aggregate within healthy families partly due to diet intake but without a significant genetic component.

Chemistry and Physics of Lipids, Nov 1, 2001

Two fluorescent probes-cis- and trans-parinaric acids were used to study the dimensions, lipid dy... more Two fluorescent probes-cis- and trans-parinaric acids were used to study the dimensions, lipid dynamics and apolipoprotein location in the reconstituted discoidal high density lipoproteins (rHDL). The rHDL particles made from apolipoprotein A-I (apoA-I), dipalmitoylphosphatidylcholine (DPPC), with or without cholesterol (Chol) were compared with the analogous particles with two other apolipoproteins-apoE and apoA-II. The data obtained for apoA-I-containing rHDL were as follows: (1) the inclusion of 8 mol.% of cholesterol did not significantly change the particle dimensions (13+/-1 nm) or the mean distance between apoA-I and the disc axis; (2) the phospholipid domains-boundary lipid region in the close vicinity to apoA-I molecule and the remaining part of the bilayer-existed at temperatures both lower and above DPPC transition temperature T(t); (3) at T&amp;lt;T(t) Chol molecules preferentially accumulated in the central area with a radius of 2.8 nm that conserved partially after DPPC phase transition; (4) inhomogeneous cholesterol distribution was assumed to exist within these domains. A hydrophobic matching concept was used to compare protein-lipid interactions in rHDL particles. For complexes with all three apolipoproteins studied, at T&amp;lt;T(t) the probe mobility in the lipid phase of rHDL was significantly higher compared to pure DPPC bilayer. After temperature-induced transition, mobility increased significantly still being lower in rHDL. The comparative study of lipid dynamics in apoA-I-, apoE- and apoA-II-containing complexes revealed the presence of boundary lipid in all three complexes without cholesterol. The degree of cholesterol exclusion from the boundary lipid region seems to increase in the order A-I&amp;lt;E&amp;lt;A-II for Chol-containing complexes, the exclusion being an inherent property of the particular apolipoprotein molecule.

Clinical Chemistry, Apr 1, 1990

We used an electroimmunoassay to measure LpAI lipoprotein particles (lipoproteins containing apol... more We used an electroimmunoassay to measure LpAI lipoprotein particles (lipoproteins containing apolipoprotein AI but not apolipoprotein AII) in serum of a presumably healthy population of about 1000 subjects, noting sex- and age-related variations for the age interval four to 70 years. Results were higher for women than men. For males, the value for the 50th percentile of the distribution was highest in the 10- to 14-year subgroup, 0.69 g/L, decreasing to 0.60 g/L in adults. For females, the values increased regularly, from 0.59 g/L at ages four to 10 years to 0.79 g/L after age 55 years. The influence of puberty, menopause, oral contraceptives, alcohol consumption, and morphometric characteristics was studied. Only being overweight by more than 20% statistically influenced LpAI values in men and in women. We used these results to select a reference population and to establish reference limits of LpAI at ages 25 to 35 years: 0.40-0.95 g/L for men and 0.46-1.05 g/L for women.

The American Journal of Clinical Nutrition, May 1, 2005

Background: Although numerous environmental factors are documented to influence serum retinol and... more Background: Although numerous environmental factors are documented to influence serum retinol and ␣-tocopherol concentrations, little is known about the genetic versus the environmental contributions to variations in these traits. Objective: The aim of this study was to estimate additive genetic heritability and household effects for serum retinol and ␣-tocopherol concentrations in a variance component analysis. Design: In a sample of 387 French families, information on serum retinol and ␣-tocopherol concentrations, usual dietary intake, lifestyle, and serum lipid profiles and related polymorphisms (apolipoprotein E, apolipoprotein C-III, apolipoprotein B, cholesteryl ester transfer protein, and lipoprotein lipase) was obtained. Results: For serum retinol-after adjustment for sex, age, body mass index, alcohol consumption, oral contraceptive use, and serum albumin, triacylglycerol, and apolipoprotein A-I concentrationsadditive genetic effects and shared common environment contributed 30.5% and 14.2% of the total variance, respectively. For serum ␣-tocopherol, Ȃ22.1% of the total variance was due to the additive effects of genes and 18.7% to those of household environment, after adjustment for the covariates sex, age, vitamin E intake, oral contraceptive use, and cholesterol, triacylglycerol, and apolipoprotein A-I concentrations. For both vitamins, the influence of measured polymorphisms was not significant. Moreover, heritability and household effect estimates were not significantly different between the 4 classes of relatives and did not vary significantly when families shared more meals at home. Conclusions: The results show that serum retinol and ␣-tocopherol concentrations are under genetic control in healthy families.

Frontiers in Medicine, Oct 11, 2022

WOS, 2010

Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain lar... more Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain largely elusive. To identify genetic loci for obesity susceptibility, we examined associations between body mass index and ~2.8 million SNPs in up to 23,865 individuals with targeted follow up of 42 SNPs in up to 25,93 additional individuals. We confirmed 4 known obesity susceptibility loci and identified 8 new loci associated with body mass index (P < 5 × 0 −8), one of which includes a copy number variant near GPRC5B. Some loci (at MC4R, POMC, SH2B1 and BDNF) map near key hypothalamic regulators of energy balance, and one of these loci is near GIPR, an incretin receptor. Furthermore, genes in other newly associated loci may provide new insights into human body weight regulation.

Nature Communications, Feb 8, 2021

Nature Genetics, May 1, 2010

In the version of this article initially published, the colony formation assay image labeled "Co1... more In the version of this article initially published, the colony formation assay image labeled "Co115.DICER1" was the incorrect image. The error has been corrected and a corrected version of Figure 4 panel e is provided in the HTML and PDF versions of the article.

Journal of Thrombosis and Haemostasis, Dec 1, 2010

F. A multi-stage multi-design strategy provides strong evidence that the BAI3 locus is associated... more F. A multi-stage multi-design strategy provides strong evidence that the BAI3 locus is associated with early-onset venous thromboembolism.