Familial resemblance of plasma lipids, lipoproteins and postheparin lipoprotein and hepatic lipases in the HERITAGE Family Study

Influence of Common Gene Variants on Lipid Levels and Risk of Coronary Heart Disease in Afro-Caribbeans

A lower mortality rate from coronary artery disease (CAD) and a more favourable lipid profile have been reported in Afro-Caribbeans compared with people of European ancestry. The aim of this study was to determine whether common lipid variants identified in other populations are associated with lipid levels and CAD in Afro-Caribbeans. We studied 705 Afro-Caribbeans (192 with CAD) who were genotyped for 13 lipid-associated variants. We calculated three polygenic risk scores (PRSs) for elevated LDL (LDL-PRS), decreased HDL (HDL-PRS), and elevated triglycerides (TG-PRS). LDL-PRS, HDL-PRS, and TG-PRS were associated with LDL, HDL, and TG levels, respectively. The LDL-PRS was positively associated with LDL > 2.6 mmol/L and with LDL > 3.0 mmol/L with ORs (odds ratios) of 1.33 (95% confidence interval (CI) = 1.14-1.56) and 1.40 (CI = 1.21-1.62), respectively. The HDL-PRS was associated with a low HDL category (HDL < 1.03 mmol/L) with an OR of 1.3 (CI = 1.04-1.63) and inversely associated with a high HDL category (HDL > 1.55 mmol/L) with an OR of 0.79 (CI = 0.65-0.96). The LDL-PRS was positively associated with CAD after adjustment for age, gender, hypertension, diabetes, and smoking with an OR of 1.27 (CI = 1.06-1.51) but not the HDL-PRS nor the TG-PRS. Results of the present study indicate that common lipid variants are associated with lipid levels and prevalent CAD in Afro-Caribbeans.

Assessment of hypercholesterolemia prevalence and its demographic variations in the Republic of Kazakhstan

Hypercholesterolemia is a major risk factor for cardiovascular disease, the leading cause of death in Kazakhstan. Understanding its prevalence is vital for effective public health planning and interventions. This study aimed to assess the scale of hypercholesterolemia in the Republic of Kazakhstan and to identify differences among distinct population groups. A cross-sectional study involving 6720 participants (a nationally representative survey.) aged 18-69 was conducted from October 2021 to May 2022 across all 17 regions of Kazakhstan. The magnitude of hypercholesterolemia was 43.5%. Cholesterol levels were determined through blood biochemical analysis. Age, sex, geographic location, and ethnicity served as covariates. The majority of participants (65.49%) were from urban areas with an almost equal gender distribution (50.07% male and 49.93% female). The predominant age groups were 18-29 years (25.71%) and 30-39 years (25.12%), and 65.09% identified as Kazakh. The prevalence increased with age, with the 60-69 age group showing the highest rate at 71.14%. Women had slightly higher rates than men. Geographical differences were evident, with regions like Astana city and Almaty region showing significant disparities. Kazakhs had a lower rate compared to other ethnicities. Age, region, and BMI were significant predictors for hypercholesterolemia in both binary and multivariate logistic regression analyses. The study revealed a significant prevalence of hypercholesterolemia in Kazakhstan, with increasing age as a major determinant. Women, especially those over 50, and certain regions showed higher cholesterol levels. The disparities observed across regions and ethnicities suggest the need for targeted public health interventions to address this pressing health concern.

Role of non-coding variants in cardiovascular disease

Cardiovascular diseases (CVDs) constitute one of the significant causes of death worldwide. Different pathological states are linked to CVDs, which despite interventions and treatments, still have poor prognoses. The genetic component, as a beneficial tool in the risk stratification of CVD development, plays a role in the pathogenesis of this group of diseases. The emergence of genome-wide association studies (GWAS) have led to the identification of non-coding parts associated with cardiovascular traits and disorders. Variants located in functional non-coding regions, including promoters/enhancers, introns, miRNAs and 5'/3' UTRs, account for 90% of all identified single-nucleotide polymorphisms associated with CVDs. Here, for the first time, we conducted a comprehensive review on the reported non-coding variants for different CVDs, including hypercholesterolemia, cardiomyopathies, congenital heart diseases, thoracic aortic aneurysms/dissections and coronary artery diseases. Additionally, we present the most commonly reported genes involved in each CVD. In total, 1469 non-coding variants constitute most reports on familial hypercholesterolemia, hypertrophic cardiomyopathy and dilated cardiomyopathy. The application and identification of non-coding variants are beneficial for the genetic diagnosis and better therapeutic management of CVDs.

The HERITAGE Family Study: A Review of the Effects of Exercise Training on Cardiometabolic Health, with Insights into Molecular Transducers

The aim of the HERITAGE Family Study was to investigate individual differences in response to a standardized endurance exercise program, the role of familial aggregation, and the genetics of response levels of cardiorespiratory fitness and cardiovascular disease and diabetes risk factors. Here we summarize the findings and their potential implications for cardiometabolic health and cardiorespiratory fitness. It begins with overviews of background and planning, recruitment, testing and exercise program protocol, quality control measures, and other relevant organizational issues. A summary of findings is then provided on cardiorespiratory fitness, exercise hemodynamics, insulin and glucose metabolism, lipid and lipoprotein profiles, adiposity and abdominal visceral fat, blood levels of steroids and other hormones, markers of oxidative stress, skeletal muscle morphology and metabolic indicators, and resting metabolic rate. These summaries document the extent of the individual differences in response to a standardized and fully monitored endurance exercise program and document the importance of familial aggregation and heritability level for exercise response traits. Findings from genomic markers, muscle gene expression studies, and proteomic and metabolomics explorations are reviewed, along with lessons learned from a bioinformatics-driven analysis pipeline. The new opportunities being pursued in integrative -omics and physiology have extended considerably the expected life of HERITAGE and are being discussed in relation to the original conceptual model of the study.

Association between a genetic variant in scavenger receptor class B type 1 and its role on codon usage bias with increased risk of developing coronary artery disease

OBJECTIVE

Coronary artery disease (CAD) as an important cause of morbidity and mortality globally. The scavenger receptor class B type 1 (SCARB1) plays an essential role in the reverse cholesterol transport. We have explored the association between a genetic variant, rs5888, in the SCARB1 gene with CAD and serum HDL-C levels.

METHODS

Patients were categorized into two groups' angiogram positive (>50% coronary stenosis) and angiogram negative (<50% coronary stenosis). Genotyping was carried out using polymerase chain reaction-amplification refractory mutation system. The association between the SNP rs5888 and serum HDL-C was analyzed using a logistic regression model.

RESULTS

The results showed that the subjects carrying a T allele was associated with a decreased serum HDL-C levels compared to the C allele in total population (p < 0.001). The risk of angiogram positivity in subjects carrying a T allele was 3.1-fold higher than for the control group (p < 0.001).

CONCLUSION

CVD patients carrying the T allele of rs5888 variant in the SCARB1 gene was associated with decreased serum level of HDL.

Candidate Gene Analysis Reveals Strong Association of CETP Variants With High Density Lipoprotein Cholesterol and PCSK9 Variants With Low Density Lipoprotein Cholesterol in Ghanaian Adults: An AWI-Gen Sub-Study

Variations in lipid levels are attributed partly to genetic factors. Genome-wide association studies (GWASs) mainly performed in European, African American and Asian cohorts have identified variants associated with LDL-C, HDL-C, total cholesterol (TC) and triglycerides (TG), but few studies have been performed in sub-Saharan Africans. This study evaluated the effect of single nucleotide variants (SNVs) in eight candidate loci (ABCA1, LCAT, LPL, PON1, CETP, PCSK9, MVK, and MMAB) on lipid levels among 1855 Ghanaian adults. All lipid levels were measured directly using an automated analyser. DNA was extracted and genotyped using the H3Africa SNV array. Linear regression models were used to test the association between SNVs and log-transformed lipid levels, adjusting for sex, age and waist circumference. In addition Bonferroni correction was performed to account for multiple testing. Several variants of CETP, LCAT, PCSK9, and PON1 (MAF > 0.05) were associated with HDL-C, LDL-C and TC levels at p < 0.05. The lead variants for association with HDL-C were rs17231520 in CETP (β = 0.139, p < 0.0001) and rs1109166 in LCAT (β = −0.044, p = 0.028). Lower LDL-C levels were associated with an intronic variant in PCSK9 (rs11806638 [β = −0.055, p = 0.027]) and increased TC was associated with a variant in PON1 (rs854558 [β = 0.040, p = 0.020]). In silico functional analyses indicated that these variants likely influence gene function through their effect on gene transcription. We replicated a strong association between CETP variants and HDL-C and between PCSK9 variant and LDL-C in West Africans, with two potentially functional variants and identified three novel variants in linkage disequilibrium in PON1 which were associated with increasing TC levels in Ghanaians.

Positive association of familial longevity with the moderate-high HDL-C concentration in Bama Aging Study

Familial longevity is characterized by beneficial metabolic phenotype in lipid metabolism and APOE genetic variation. Although effects of lipid metabolism and the genetic basis for human longevity remain largely unclear, the contribution of high-density lipoprotein cholesterol (HDL-C) and APOE ε2 allele has been repeatedly demonstrated. This study was designed to determine whether ApoE isoforms and HDL-C levels marked the familial longevity status in an offspring cohort with the age range of 20-89 years old and subsequently to explore the correlation between these two markers and the aging. In the Bama Aging Study (BAS), we recruited 312 offspring from longevity historical families and 298 controls from non-longevity historical families. Information on APOE genotype frequencies, lipid levels, and population characteristics were recorded. No evidence was found to support the association of APOE genotypes with HDL-C and age. HDL-C was significantly higher in longevity group (p < 0.0001). Scatter plot showed a moderately strong linear relationship between the HDL-C level and age in longevity group (r = 0.213, p < 0.001). We conclude that the variation of the APOE gene may not influence familial longevity status at a certain age but the moderate-high HDL-C level contributes to the familial longevity in Bama.

Effect of Participation with Accompanying Household Member in the Complete Health Improvement Program in Appalachia

Intensive therapeutic lifestyle modification programs, such as the Complete Health Improvement Program (CHIP), reduce cardiovascular disease (CVD) risk factors. However, there are little data on how participation in CHIP with a household member can affect CVD biomarkers. This study focuses on the benefit of joint participation of household members in CHIP in order to have a better outcome in improving CVD risk factors compared with lone or individual participation. Data from 20 CHIP classes offered from 2011 to 2015 in Athens, Ohio, where each class was conducted over 2-4 months, consisting of 16-18 sessions, were collected. Body mass index (BMI), blood pressure, fasting glucose, and lipid profiles were measured before and near the completion of each class. A statistically significant greater reduction in BMI (p = 0.003) in those who attended with a household member compared to those who attended as individuals was found. CHIP has some effect on various CVD risk factors for those who attend intensive therapeutic lifestyle modification programs with an accompanying household member. Hence, encouragement of participation with a family member or a “buddy” may be prudent, especially if weight reduction is a key program participation goal. Further evaluation of the “buddy effect” involving both of those residing in the same household and those who do not but nevertheless provide mutual support is warranted.

Association between the LIPG polymorphisms and serum lipid levels in the Maonan and Han populations

Introduction

The Maonan population is a relatively isolated minority in China. Little is known about endothelial lipase gene (LIPG) single nucleotide polymorphisms (SNPs) and serum lipid levels in the Chinese populations. The present study aimed to detect the association of several LIPG SNPs and environmental factors with serum lipid levels in the Chinese Maonan and Han populations.

Methods

In total, 773 subjects of Maonan ethnicity and 710 participants of Han ethnicity were randomly selected from our previous stratified randomized samples. Genotypes of the LIPG rs2156552, rs4939883 and rs7241918 SNPs were determined by polymerase chain reaction‐restriction fragment length polymorphism, and then confirmed by direct sequencing.

Results

The allelic (rs2156552, rs4939883 and rs7241918) and genotypic (rs2156552 and rs4939883) frequencies were different between the two ethnic groups (p < 0.05–0.01). The minor allele carriers had lower apolipoprotein (Apo)A1/ApoB ratio (rs2156552 and rs7241918), high‐density lipoprotein cholesterol (HDL‐C) and apolipoprotein (Apo)A1 (rs2156552) levels and higher ApoB levels (rs4939883) in the Han population, and lower HDL‐C (rs2156552, rs4939883 and rs7241918) levels in the Maonan minority than the minor allele non‐carriers (p < 0.0167 after Bonferroni correction). Subgroup analyses according to sex showed that the minor allele carriers had a lower ApoA1/ApoB ratio (rs2156552 and rs7241918) and higher ApoB levels (rs7241918) in Han males, and lower ApoA1 and HDL‐C levels in Maonan females than the minor allele non‐carriers (p < 0.0167–0.001).

Conclusions

The present study demonstrates the association between the LIPG polymorphsims and serum lipid levels in the two ethnic groups. These associations might have an ethnic‐ and or/sex‐specificity.

BCL3-PVRL2-TOMM40 SNPs, gene-gene and gene-environment interactions on dyslipidemia

Little is known about the association of the BCL3-PVRL2-TOMM40 SNPs and dyslipidemia. This study was to detect 12 BCL3-PVRL2-TOMM40 SNPs, gene-gene and gene-environment interactions on dyslipidemia in the Chinese Maonan population. Genotyping was performed in 1130 normal and 832 dyslipidemia participants. Generalized multifactor dimensionality reduction was used to screen the best interaction combination among SNPs and environmental exposures. Allele and genotype frequencies of the detected SNPs were different between the two groups (P < 0.05-0.001). Association of the 12 SNPs and serum lipid levels was observed (P < 0.004-0.001). Multiple-locus linkage disequilibrium was not statistically independent in the population (D' = 0.01-0.98). The dominant model of rs8100239 and rs157580 SNPs, several haplotypes and G × G interaction haplotypes contributed to a protection, whereas the dominant model of rs10402271, rs3810143, rs519113, rs6859 SNPs, another haplotypes and G × G interaction haplotypes revealed an increased morbidity function (P < 0.05-0.001). There were significant three-locus model involving SNP-SNP, SNP-environment, haplotype-haplotype interactions (P < 0.05-0.001). The subjects carrying several genotypes and haplotypes decreased dyslipidemia risk, whereas the subjects carrying other genotypes and haplotypes increased dyslipidemia risk. The BCL3-PVRL2-TOMM40 SNPs, gene-gene and gene-environment interactions on dyslipidemia were observed in the Chinese Maonan population.

Rare non-coding variants are associated with plasma lipid traits in a founder population

Founder populations are ideally suited for studies on the clinical effects of alleles that are rare in general populations but occur at higher frequencies in these isolated populations. Whole genome sequencing in 98 Hutterites, a founder population of European descent, and subsequent imputation revealed 660,238 single nucleotide polymorphisms that are rare (<1%) or absent in European populations, but occur at frequencies >1% in the Hutterites. We examined the effects of these rare in European variants on plasma lipid levels in 828 Hutterites and applied a Bayesian hierarchical framework to prioritize potentially causal variants based on functional annotations. We identified two novel non-coding rare variants associated with LDL cholesterol (rs17242388 in LDLR) and HDL cholesterol (rs189679427 between GOT2 and APOOP5), and replicated previous associations of a splice variant in APOC3 (rs138326449) with triglycerides and HDL-C. All three variants are at well-replicated loci in GWAS but are independent from and have larger effect sizes than the known common variation in these regions. Candidate eQTL analyses in in LCLs in the Hutterites suggest that these rare non-coding variants are likely to mediate their effects on lipid traits by regulating gene expression.

Association between the MVK and MMAB polymorphisms and serum lipid levels

Maonan ethnic group is a relatively conservative and isolated minority in China. Little is known about the association of the mevalonate kinase (MVK), methylmalonic aciduria (cobalamin deficiency) cblB type (MMAB) single nucleotide polymorphisms (SNPs) and serum lipid levels. This study aimed to determine the association between four SNPs in the MVK/MMAB and serum lipid levels. Genotyping of the rs3759387, rs877710, rs7134594 and rs9593 SNPs was performed in 1264 Maonan subjects and 1251 Han participants. Allele and genotype frequencies of the selected SNPs were different between the two populations (P < 0.05-0.001). Four SNPs were associated with high-density lipoprotein cholesterol (HDL-C) in the both ethnic groups (P < 0.0125-0.001); and one SNP with apolipoprotein (Apo) A1 (rs7134594) in Han Chinese (P <0.0125). Strong linkage disequilibria were noted among the SNPs (D'=0.63-0.96; r² =0.13-0.88). The commonest haplotype was C-C-C-T (> 50%). The frequencies of C-C-C-T, C-G-T-A, A-G-T-A, C-G-C-T, and A-C-T-A were different between the two populations (P <0.001). The associations between haplotypes and dyslipidemia were different in the Han and/or Maonan population (P < 0.05-0.001), haplotypes could explain much more serum lipid variation than any single SNP alone especially for HDL-C. Differences in lipid profiles between the two populations might partially attribute to these SNPs and their haplotypes.

Heritability, parental transmission and environment correlation of pediatric-onset type 2 diabetes mellitus and metabolic syndrome-related traits

AIM

To estimate the heritability, parental transmission and environmental contributions to the phenotypic variation in type 2 diabetes mellitus and metabolic syndrome-related traits in families of Mexican children and adolescents.

METHODS

We performed a cross-sectional study of 184 tri-generational pedigrees with a total of 1160 individuals (99 families with a type 2 diabetes mellitus proband before age 19). The family history of type 2 diabetes mellitus in three generations was obtained by interview. Demographic, anthropometric, biochemical and lifestyle information was corroborated in parents and offspring. We obtained correlations for metabolic traits between relative pairs, and variance component methods were used to determine the heritability and environmental components.

RESULTS

The heritability of early-onset of type 2 diabetes mellitus was 0.50 (p<1.0e-7). The heritability was greater than 0.5 for hypertension, hypoalphalipoproteinemia, hypercholesterolemia, body mass index, waist circumference, blood pressure, 2-h insulin, and cholesterol (p<0.001). In contrast, we observed a high environmental correlation (>0.50) for blood pressure, HbA1c and HDL-cholesterol after multivariate adjustment (p<0.05). Several traits, such as type 2 diabetes mellitus and insulin resistance, were significantly correlated only through the mother and others, such as hypertriglyceridemia, were significantly correlated only through the father.

CONCLUSION

This study demonstrates that type 2 diabetes mellitus and metabolic syndrome-related traits are highly heritable among Mexican children and adolescents. Furthermore, several cardiometabolic factors have strong heritability and/or high environmental contributions that highlight the complex architecture of these alterations.

Genetic contribution to lipid levels in early life based on 158 loci validated in adults: the FAMILY study

The contribution of polymorphisms associated with adult lipids in early life is unknown. We studied 158 adult lipid polymorphisms in 1440 participants (544 children, 544 mothers and 324 fathers) of the Family Atherosclerosis Monitoring In early life (FAMILY) birth cohort. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) measurements were collected at birth, 3 and 5 years of age. Polymorphisms were genotyped using the Illumina Cardio-Metabochip array. Genotype scores (GS) were calculated for TC, HDL-C, LDL-C and TG. Linear and mixed-effects regressions adjusted for sex, age and population stratification were performed. The GS was associated with LDL-C level at 3 and 5 years (β = 0.017 ± 0.003, P = 2.9 × 10⁻⁸; β = 0.020 ± 0.003, P = 5.7 × 10⁻⁹) and from birth to 5 years (β = 0.013 ± 0.003, P = 2.6 × 10⁻⁷). The GS was associated with TC level at 3 and 5 years (β = 0.009 ± 0.002, P = 9.1 × 10⁻⁷; β = 0.009 ± 0.002, P = 7.7 × 10⁻⁶). CETP rs3764261 was associated with the HDL-C level from birth to 5 years (β = 0.064 ± 0.014, P =  7.4 × 10⁻⁶). AMPD3 rs2923084 was associated with the HDL-C level at 5 years (β = 0.096 ± 0.024, P = 9.7 × 10⁻⁵). Known loci associated with blood lipids in adults are associated with TC, LDL-C and HDL-C, but not TG in early life. Genetically predisposed children may benefit from early lipid lowering preventative strategies.

Association of the SPTLC3 rs364585 polymorphism and serum lipid profiles in two Chinese ethnic groups

BACKGROUND

Little is known about the association of the single nucleotide polymorphism (SNP) of rs364585 near serine palmitoyl-transferase long-chain base subunit 3 gene (SPTLC3) and serum lipid profiles. The present study was detected the association of the SPTLC3 rs364585 SNP and several environmental factors with serum lipid profiles in the Han and Jing populations.

METHODS

Genotyping of the SPTLC3 rs364585 SNP was performed in 824 unrelated individuals of Han and 783 participants of Jing by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

RESULTS

There was no significant difference in either genotypic or allelic frequencies between Han and Jing, or between males and females of the both ethnic groups. The levels of serum low-density lipoprotein cholesterol (LDL-C) and the ratio of apolipoprotein (Apo) A1 to ApoB in Han; and total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and LDL-C in Jing were different between the A allele carriers and the A allele non-carriers (P < 0.05-0.001). Subgroup analysis according to sex showed that the levels of LDL-C in Han males; TC and LDL-C in Jing males; and HDL-C and LDL-C in Jing females were different between the A allele carriers and the A allele non-carriers (P < 0.05-0.001), the A allele carriers had higher LDL-C and TC levels, and lower HDL-C levels than the A allele non-carriers. Serum lipid traits were also associated with several environmental factors in the Han and Jing populations, or in males and females of the both ethnic groups.

CONCLUSIONS

The present study demonstrates the association between the SPTLC3 rs364585 SNP and serum TC, HDL-C and LDL-C levels in our study populations. These associations might have ethnic- and/or sex-specificity.

TRIAL REGISTRATION

Retrospectively registered.

Association of the angiopoietin-like protein 8 rs2278426 polymorphism and several environmental factors with serum lipid levels

The present study was performed to examine the association of the angiopoietin-like protein 8 (ANGPTL8) rs2278426 single nucleotide polymorphism (SNP) and several environmental factors with serum lipid profiles in the Mulao and Han populations. A total of 879 individuals of the Mulao ethnic group and 865 individuals of the Han Chinese ethnic group were included. The serum apolipoprotein (Apo) B level was higher, however the serum ApoA1 level was lower in the Mulao individuals than in the Han individuals (P<0.05 and P<0.001, respectively). The genotypic and allelic frequencies, and the association with the ANGPTL8 rs2278426 SNP were different between the Mulao and Han populations. The frequency of the A allele was 17.80% in Han individuals and 23.04% in Mulao individuals (P<0.001). The frequencies of GG, GA and AA genotypes were 68.79, 26.82 and 4.39% in the Han population, and 60.64, 32.65 and 6.71% in the Mulao population (P<0.005), respectively. A significant association between the SNP and serum lipid traits was only detected in Han females and not in Han males or in the Mulao population. The subjects with GA/AA genotypes had lower low-density lipoprotein cholesterol (LDL-C) and ApoB levels, and higher ApoA1 levels with a higher ApoA1/ApoB ratio than the subjects with the GG genotype in the Han population. Subgroup analyses revealed that the subjects with the GA/AA genotype had lower levels of total cholesterol, LDL-C and ApoB, and a higher ApoA1/ApoB ratio than the subjects with the GG genotype in Han females (P<0.05-P<0.001). Serum lipid parameters were also associated with several environmental factors, including dietary patterns, lifestyle, obesity, physical inactivity and hypertension, in the two ethnic groups (P<0.05-0.001). These findings suggest that there may be an ethnic- and gender-specific association of the rs2278426 SNP and serum lipid parameters.

Are there genetic paths common to obesity, cardiovascular disease outcomes, and cardiovascular risk factors?

Clustering of obesity, coronary artery disease, and cardiovascular disease risk factors is observed in epidemiological studies and clinical settings. Twin and family studies have provided some supporting evidence for the clustering hypothesis. Loci nearest a lead single nucleotide polymorphism (SNP) showing genome-wide significant associations with coronary artery disease, body mass index, C-reactive protein, blood pressure, lipids, and type 2 diabetes mellitus were selected for pathway and network analyses. Eighty-seven autosomal regions (181 SNPs), mapping to 56 genes, were found to be pleiotropic. Most pleiotropic regions contained genes associated with coronary artery disease and plasma lipids, whereas some exhibited coaggregation between obesity and cardiovascular disease risk factors. We observed enrichment for liver X receptor (LXR)/retinoid X receptor (RXR) and farnesoid X receptor/RXR nuclear receptor signaling among pleiotropic genes and for signatures of coronary artery disease and hepatic steatosis. In the search for functionally interacting networks, we found that 43 pleiotropic genes were interacting in a network with an additional 24 linker genes. ENCODE (Encyclopedia of DNA Elements) data were queried for distribution of pleiotropic SNPs among regulatory elements and coding sequence variations. Of the 181 SNPs, 136 were annotated to ≥ 1 regulatory feature. An enrichment analysis found over-representation of enhancers and DNAse hypersensitive regions when compared against all SNPs of the 1000 Genomes pilot project. In summary, there are genomic regions exerting pleiotropic effects on cardiovascular disease risk factors, although only a few included obesity. Further studies are needed to resolve the clustering in terms of DNA variants, genes, pathways, and actionable targets.

A genetically informed test of cholesterol levels and self-control, depressive symptoms, antisocial behavior, and neuroticism

BACKGROUND

Low cholesterol levels have been found to be associated with a wide range of behavioral problems, including violent and criminal behavior, and a wide range of psychological problems including impulsivity, depression, and other internalizing problems. The casual mechanisms underlying these associations remain largely unknown, but genetic factors may play a role in the etiology of such associations as previous research has found significant genetic influence on cholesterol levels and various deleterious behavioral and psychological outcomes. The current study addressed this existing gap in the literature by performing a genetically sensitive test of the association between cholesterol levels and various outcomes including levels of self-control, depressive symptoms, anger expression, and neuroticism.

METHODS

DeFries-Fulker (DF) analysis was used to analyze data from 388 twin pairs nested within the Survey of Midlife Development in the United States (MIDUS).

RESULTS

The results of the genetically informed models revealed that high-density lipoprotein (HDL) cholesterol levels were negatively and significantly associated with depressive symptoms, had a marginally significant effect on neuroticism, and a nonsignificant effect on both anger expression and self-control.

LIMITATIONS

The findings may not extrapolate to the larger population of American adults since the subsample of twins with cholesterol information may not be nationally representative.

CONCLUSIONS

Genetic influences play a significant role in the association between cholesterol levels and various deleterious outcomes and failing to control for these influences may result in model misspecification and may increase the probability of detecting a significant association when one does not actually exist.

Association of cholesteryl ester transfer protein genotypes with paraoxonase-1 activity, lipid profile and oxidative stress in type 2 diabetes mellitus: A study in San Luis, Argentina

Aims/Introduction

Diabetic dyslipidemia is common in type 2 diabetes. The TaqIB polymorphism in cholesteryl ester transfer protein (CETP; B1 and B2 alleles; rs708272) is associated with changes in enzyme activity and lipid concentrations. The aim of the present study was to assess associations of CETP genotypes with lipoprotein profile, oxidant/anti-oxidant status and the plasma activity of paraoxonase-1 (PON-1) in a population of diabetic patients living in San Luis, Argentina.

Materials and Methods

For oxidative stress status parameters, thiobarbituric acid-reactive substances (TBARS) and nitric oxide (NO) levels, and catalase and PON-1 activity were assessed in 40 patients with type 2 diabetes mellitus and 30 healthy participants. CETP polymorphism was analyzed by polymerase chain reaction-based methods.

Results

Type 2 diabetes mellitus had significantly higher concentrations of oxidative stress parameters: TBARS (P < 0.0001) and catalase activity (P < 0.0001). PON-1 activity and NO levels were significantly lower in diabetics (P = 0.0002 and P = 0.0008, respectively). The CETP genotypes distribution among study groups was not significantly different. The B2 carriers of the TaqIB CETP polymorphism are associated with higher high-density lipoprotein cholesterol levels and PON-1 activity in control and type 2 diabetes mellitus patients. Linear regression analysis showed that there was a significant and positive correlation between the changes of PON-1 activity and high-density lipoprotein cholesterol levels in non-B1B1 (B2 carriers) in controls (r = 0.83, P < 0.0001) and diabetic patients (r = 0.39, P = 0.0003).

Conclusions

The results of the current study show that type 2 diabetes mellitus is characterized by intense oxidative stress, and that the alterations observed in the lipoprotein profile and PON-1 activity might be related to the higher CETP activity in diabetic patients as a consequence of insulin resistance.

Association between the MLX interacting protein-like, BUD13 homolog and zinc finger protein 259 gene polymorphisms and serum lipid levels

This study aimed to detect the association between the MLX interacting protein-like (MLXIPL), BUD13 homolog (BUD13) and zinc finger protein 259 (ZNF259) single nucleotide polymorphisms (SNPs) and serum lipid levels in the Chinese Mulao and Han populations. Genotyping of 9 SNPs was performed in 825 Mulao and 781 Han participants. The genotype and allele frequencies of ZNF259 rs2075290 and rs964184, and BUD13 rs10790162 SNPs were different between the Mulao and Han populations (P < 0.001). The SNPs of ZNF259 rs2075290 and BUD13 rs10790162 were associated with serum total cholesterol levels; ZNF259 rs2075290 and rs964184, BUD13 rs10790162, and MLXIPL rs3812316 and rs13235543 were associated with triglyceride (TG); and MLXIPL rs35332062 was associated with apolipoprotein (Apo) A1 in the Mulaos (P < 0.006–0.001). However, in the Hans, the SNPs of ZNF259 rs2075290 and BUD13 rs10790162 were associated with serum TG levels; ZNF259 rs2075290 was associated with low-density lipoprotein cholesterol and the ApoA1/ApoB ratio (P < 0.006–0.001). Significant linkage disequilibria were noted among ZNF259 rs2075290 and rs964184 and BUD13 rs10790162, and between MLXIPL rs3812316 and rs13235543 (r² > 0.05, P < 0.001). The haplotypes of A-C-G-A-C (rs2075290A-rs964184C-rs10790162G-rs17119975A-rs11556024C) and C-C-C-C (rs799161C-rs35332062C-rs3812316C-rs13235543C) accounted for over half of the % haplotype of each ethnic group.

Genetic predisposition scores for dyslipidaemia influence plasma lipid concentrations at baseline, but not the changes after controlled intake of n-3 polyunsaturated fatty acids

Inconsistent effects of fish oil supplementation on plasma lipids may be influenced by genetic variation. We investigated 12 single nucleotide polymorphisms (SNPs) associated with dyslipidaemia in genome-wide association studies, in 310 participants randomised to treatment with placebo or 0.45, 0.9 and 1.8 g/day eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) (1.51:1) in a 12-month parallel controlled trial. Effects of risk alleles were assessed as trait-specific genetic predisposition scores (GPS) and singly. GPS were positively associated with baseline concentrations of plasma total cholesterol, low-density-lipoprotein cholesterol and triglyceride (TG) and negatively with high-density-lipoprotein cholesterol. The TG-GPS was associated with 0.210 mmol/L higher TG per risk allele (P < 0.0001), but no effects of single TG SNPs were significant at baseline. After treatment with EPA and DHA, TG-GPS was associated with 0.023 mmol/L lower TG per risk allele (P = 0.72). No interactions between GPS and treatment were significant; however, FADS1 SNP rs174546 C/T interaction with treatment was a significant determinant of plasma TG concentration (P = 0.047, n = 267). Concentration differed between genotype groups after the 1.8 g/day dose (P = 0.026), decreasing by 3.5 (95 % CI -15.1 to 8.2) % in non-carriers of the risk T-allele (n = 30) and by 21.6 (95 % CI -32.1 to -11.2) % in carriers (n = 37), who showed a highly significant difference between treatments (P = 0.007). Carriers of the FADS1 rs174546 risk allele could benefit from a high intake of EPA and DHA in normalising plasma TG.

Genetic architecture of lipid traits changes over time and differs by race: Princeton Lipid Follow-up Study

Dyslipidemia is a major risk factor for CVD. Previous studies on lipid heritability have largely focused on white populations assessed after the obesity epidemic. Given secular trends and racial differences in lipid levels, this study explored whether lipid heritability is consistent across time and between races. African American and white nuclear families had fasting lipids measured in the 1970s and 22-30 years later. Heritability was estimated, and bivariate analyses between visits were conducted by race using variance components analysis. A total of 1,454 individuals (age 14.1/40.6 for offspring/parents at baseline; 39.6/66.5 at follow-up) in 373 families (286 white, 87 African American) were included. Lipid trait heritabilities were typically stronger during the 1970s than the 2000s. At baseline, additive genetic variation for LDL was significantly lower in African Americans than whites (P = 0.015). Shared genetic contribution to lipid variability over time was significant in both whites (all P < 0.0001) and African Americans (P ≤ 0.05 for total, LDL, and HDL cholesterol). African American families demonstrated shared environmental contributions to lipid variation over time (all P ≤ 0.05). Lower heritability, lower LDL genetic variance, and durable environmental effects across the obesity epidemic in African American families suggest race-specific approaches are needed to clarify the genetic etiology of lipids.

Association of the variants in the BUD13-ZNF259 genes and the risk of hyperlipidaemia

The single nucleotide polymorphisms (SNPs) in the BUD13 homolog (BUD13) and zinc finger protein 259 (ZNF259) genes have been associated with one or more serum lipid traits in the European populations. However, little is known about such association in the Chinese populations. Our objectives were to determine the association of the BUD13/ZNF259 SNPs and their haplotypes with hypercholesterolaemia (HCH)/hypertriglyceridaemia (HTG) and to identify the possible gene–gene interactions among these SNPs. Genotyping of 6 SNPs was performed in 634 hyperlipidaemic and 547 normolipidaemic participants. The ZNF259 rs2075290, ZNF259 rs964184 and BUD13 rs10790162 SNPs were significantly associated with serum lipid levels in both HCH and non-HCH populations (P < 0.008–0.001). On single locus analysis, only BUD13 rs10790162 was associated with HCH (OR: 2.23, 95% CI: 1.05, 4.75, P = 0.015). The G-G-A-A-C-C haplotype, carrying rs964184-G-allele, was associated with increased risk of HCH (OR: 1.35, 95% CI: 1.10, 1.66, P = 0.005) and HTG (OR: 1.75, 95% CI: 1.39, 2.21, P= 0.000). The A-C-G-G-C-C and A-C-A-G-T-C haplotypes, carrying rs964184-C-allele, were associated with reduced risk of HCH (OR: 0.77, 95% CI: 0.61, 0.99, P = 0.039 and OR: 0.66, 95% CI: 0.47, 0.94, P= 0.021 respectively). On multifactor dimensionality reduction analyses, the two- to three-locus models showed a significant association with HCH and HTG (P < 0.01–0.001). The BUD13/ZNF259 SNPs, which were significant in the European populations, are also replicable in the Southern Chinese population. Moreover, inter-locus interactions may exist among these SNPs. However, further functional studies are required to clarify how these SNPs and genes actually affect the serum lipid levels.

Advances in understanding stroke risk in children--a geneticist's view

The advent of the genomic era has provided novel insights into the genetic architecture of common complex diseases, such as thrombophilia and stroke. Since 2006, a growing number of genome wide association studies (GWAS) for common complex diseases have revealed new candidate loci and genomic regions that play an important role in disease aetiology and progression. While GWAS on the above mentioned traits are abundant in adults, similar studies in paediatric study cohorts are lagging behind. However, genetic research in this important clinical area has gained momentum and starts to provide us with exciting insights into the genetic underpinnings of stroke with paediatric onset. Here we review recent advances in genetic association studies underlying stroke in children and aim to translate the results to clinical utility. These studies comprise candidate gene approaches and GWAS, and represent the current status on what we have learnt about the genetic architecture underlying paediatric stroke, and how this may affect medical practice in the years to come.

Association of the KLF14 rs4731702 SNP and serum lipid levels in the Guangxi Mulao and Han populations

The objective of the present study was to detect the association of the rs4731702 single nucleotide polymorphism (SNP) and serum lipid levels in the Guangxi Mulao and Han populations. A total of 727 subjects of Mulao and 740 subjects of Han Chinese were included. Serum low-density lipoprotein cholesterol (LDL-C) and apolipoprotein (Apo) B levels were higher in Mulao than in Han (P < 0.05). The T allele carriers had higher serum LDL-C and ApoAI levels in Mulao, whereas they had lower high-density lipoprotein cholesterol (HDL-C) levels and ratio of ApoAI to ApoB in Han (P < 0.05) than the T allele noncarriers. Subgroup analyses showed that the T allele carriers had higher HDL-C, LDL-C, and ApoAI levels in Mulao males and lower ApoAI levels and ratio of ApoAI to ApoB in Han males than the T allele noncarriers. The subjects with TT genotype in Han females also had higher total cholesterol, LDL-C, ApoAI, and ApoB levels than the subjects with CT or CC genotype. Serum lipid parameters were also correlated with several environmental factors in both ethnic groups. The differences in the association of KLF14 rs4731702 SNP and serum lipid levels between the two ethnic groups might partly result from different gene-environmental interactions.

Do genetic modifiers of high-density lipoprotein cholesterol and triglyceride levels also modify their response to a lifestyle intervention in the setting of obesity and type-2 diabetes mellitus?: The Action for Health in Diabetes (Look AHEAD) study

BACKGROUND

High-density lipoprotein cholesterol (HDL-C) and triglycerides are cardiovascular risk factors susceptible to lifestyle behavior modification and genetics. We hypothesized that genetic variants identified by genome-wide association studies as associated with HDL-C or triglyceride levels modify 1-year treatment response to an intensive lifestyle intervention, relative to a usual care of diabetes mellitus support and education.

METHODS AND RESULTS

We evaluated 82 single-nucleotide polymorphisms, which represent 31 loci demonstrated by genome-wide association studies to be associated with HDL-C and triglycerides, in 3561 participants who consented for genetic studies and met eligibility criteria. Variants associated with higher baseline HDL-C levels, cholesterol ester transfer protein (CETP) rs3764261 and hepatic lipase (LIPC) rs8034802, were found to be associated with HDL-C increases with intensive lifestyle intervention (P=0.0038 and 0.013, respectively) and had nominally significant treatment interactions (P=0.047 and 0.046, respectively). The fatty acid desaturase-2 rs1535 variant, associated with low baseline HDL-C (P=0.017), was associated with HDL-C increases with intensive lifestyle intervention (0.0037) and had a nominal treatment interaction (P=0.035). Apolipoprotein B (rs693) and LIPC (rs8034802) single-nucleotide polymorphisms showed nominally significant associations with HDL-C and triglyceride changes with intensive lifestyle intervention and a treatment interaction (P<0.05). Phosphatidylglycerophosphate synthase-1 single-nucleotide polymorphisms (rs4082919) showed the most significant triglyceride treatment interaction in the full cohort (P=0.0009).

CONCLUSIONS

This is the first study to identify genetic variants modifying lipid responses to a randomized lifestyle behavior intervention in overweight or obese individuals with diabetes mellitus. The effects of genetic factors on lipid changes may differ from the effects on baseline lipids and are modifiable by behavioral intervention.

Familial resemblance of bone turnover rate in men aged 40 and over-the MINOS study

Familial resemblance of bone mineral density (BMD) is well known in both sexes. Fewer data concern the familial resemblance of bone turnover markers (BTMs) and bone size in men. Our aim was to assess the correlation of BMD, bone size, BTM levels and hormones regulating bone turnover in 50 pairs of brothers aged ≥ 40 and 50 pairs of unrelated men matched for age, weight and height. BMD was measured at the lumbar spine, hip, forearm and whole body. We measured serum osteocalcin (OC), bone-specific alkaline phosphatase (bone ALP), N-terminal propeptide of type I procollagen (PINP) and C-terminal telopeptide of type I collagen (CTX-I) as well as urinary free and total deoxypyridinoline (DPD) and CTX-I. After adjustment for age, weight, bioavailable 17β-estradiol, and parathyroid hormone, all the BTMs (except bone ALP) were significantly correlated in the brothers (ICC = 0.36-0.64). Most of these correlations were significantly stronger than in the unrelated men. Bone size correlated significantly between the brothers (ICC = 0.55-0.65). These correlations were significantly stronger than in the unrelated men. BMD correlated between the brothers at most of the skeletal sites and, for some of them, more strongly than in the unrelated men. Serum levels of LDL-cholesterol and triglycerides were significantly correlated in the brothers, but not more strongly than in the unrelated men. BTM levels correlated independently in the brothers aged ≥ 40, when their shared environment was limited. These data suggest a substantial hereditary determinism of the BTM levels in men.

Sedentary behaviour, visceral fat accumulation and cardiometabolic risk in adults: a 6-year longitudinal study from the Quebec Family Study

Background

Sedentary behaviour has recently emerged as a unique risk factor for chronic disease morbidity and mortality. One factor that may explain this relationship is visceral adiposity, which is prospectively associated with increased cardiometabolic risk and mortality. The objective of the present study was to determine whether sedentary behaviour was associated with increased accumulation of visceral fat or other deleterious changes in cardiometabolic risk over a 6-year follow-up period among adult participants in the Quebec Family Study.

Methods

The current study included 123 men and 153 women between the ages of 18 and 65. Total sedentary time and physical activity were assessed by self-report questionnaire. Cross-sectional areas of visceral and subcutaneous abdominal adipose tissue were assessed using computed tomography. Cardiometabolic biomarkers including fasting insulin, glucose, blood lipids, HOMA-Insulin Resistance, and oral glucose tolerance were also measured. All variables of interest were collected at both baseline and follow-up.

Results

After adjustment for age, sex, baseline BMI, physical activity, energy intake, smoking, education, income and menopausal status, baseline sedentary behaviour was not associated with changes in visceral adiposity or any other marker of cardiometabolic risk. In the longitudinal model which adjusted for all studied covariates, every 15-minute increase in sedentary behaviour from baseline to follow-up was associated with a 0.13 cm increase in waist circumference (95% CI = 0.02, 0.25). However, there was no association between changes in sedentary behaviour and changes in visceral adiposity or other markers of cardiometabolic risk.

Conclusion

These results suggest that neither baseline sedentary behaviour nor changes in sedentary behaviour are associated with longitudinal changes in visceral adiposity in adult men and women. With the exception of waist circumference, the present study did not find evidence of a relationship between sedentary behaviour and any marker of cardiometabolic risk in this population.

The effect of excess weight gain with intensive diabetes mellitus treatment on cardiovascular disease risk factors and atherosclerosis in type 1 diabetes mellitus: results from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study (DCCT/EDIC) study

BACKGROUND

Intensive diabetes mellitus therapy of type 1 diabetes mellitus reduces diabetes mellitus complications but can be associated with excess weight gain, central obesity, and dyslipidemia. The purpose of this study was to determine whether excessive weight gain with diabetes mellitus therapy of type 1 diabetes mellitus is prospectively associated with atherosclerotic disease.

METHODS AND RESULTS

Subjects with type 1 diabetes mellitus (97% white, 45% female, mean age 35 years) randomly assigned to intensive or conventional diabetes mellitus treatment during the Diabetes Control and Complications Trial (DCCT) underwent intima-media thickness (n = 1015) and coronary artery calcium score (n = 925) measurements during follow-up in the Epidemiology of Diabetes Interventions and Complications (EDIC) Study. Intensive treatment subjects were classified by quartile of body mass index change during the DCCT. Excess gainers (4th quartile, including conventional treatment subjects meeting this threshold) maintained greater body mass index and waist circumference, needed more insulin, had greater intima-media thickness (+5%, P < 0.001 EDIC year 1, P = 0.003 EDIC year 6), and trended toward greater coronary artery calcium scores (odds ratio, 1.55; confidence interval, 0.97 to 2.49; P = 0.07) than minimal gainers. DCCT subjects meeting metabolic syndrome criteria for waist circumference and blood pressure had greater intima-media thickness in both EDIC years (P = 0.02 to < 0.001); those meeting high-density lipoprotein criteria had greater coronary artery calcium scores (odds ratio, 1.6; confidence interval, 1.1 to 2.4; P = 0.01) during follow-up. Increasing frequency of a family history of diabetes mellitus, hypertension, and hyperlipidemia was associated with greater intima-media thickness with intensive but not conventional treatment.

CONCLUSIONS

Excess weight gain in DCCT is associated with sustained increases in central obesity, insulin resistance, dyslipidemia and blood pressure, as well as more extensive atherosclerosis during EDIC.

CLINICAL TRIAL REGISTRATION

URL for DCCT: http://clinicaltrials.gov; Unique identifier: NCT00360815. URL for EDIC: http://clinicaltrials.gov; Unique identifier: NCT00360893.

High-density lipoprotein (HDL) particle subpopulations in heterozygous cholesteryl ester transfer protein (CETP) deficiency: maintenance of antioxidative activity

Cholesteryl ester transfer protein (CETP) deficiency causes elevated high-density lipoprotein-cholesterol (HDL-C) levels; its impact on HDL functionality however remains elusive. We compared functional and compositional properties of HDL derived from 9 Caucasian heterozygous CETP mutation carriers (splice-site mutation in intron 7 resulting in premature truncation) with those of 9 age- and sex-matched normolipidemic family controls. As expected, HDL-C levels were increased 1.5-fold, and CETP mass and activity were decreased by −31% and −38% respectively, in carriers versus non-carriers. HDL particles from carriers were enriched in CE (up to +19%, p<0.05) and depleted of triglycerides (TG; up to −54%, p<0.01), resulting in a reduced TG/CE ratio (up to 2.5-fold, p<0.01). In parallel, the apoA-I content was increased in HDL from carriers (up to +22%, p<0.05). Both the total HDL fraction and small, dense HDL3 particles from CETP-deficient subjects displayed normal antioxidative activity by attenuating low-density lipoprotein oxidation with similar efficacy on a particle mass basis as compared to control HDL3. Consistent with these data, circulating levels of systemic biomarkers of oxidative stress (8-isoprostanes) were similar between the two groups. These findings support the contention that HDL functionality is maintained in heterozygous CETP deficiency despite modifications in lipid and protein composition.

Effect of the SORT1 low-density lipoprotein cholesterol locus is sex-specific in a fit, Canadian young-adult population

The SORT1 locus was originally identified by genome-wide association studies of low-density lipoprotein cholesterol (LDL-C) in adults. Although the effect sizes of this locus are relatively small, we hypothesized that a younger population would show a greater genetic effect because of fewer confounding variables. As such, we investigated the association between the SORT1 locus and LDL-C in a group of healthy young adults. Subjects (n = 122, mean age = 23.2 years) were recruited from the University of Calgary. Lipid measures and genomic DNA were collected from peripheral blood after an overnight fast. Blood pressure, percent body fat (%BF), and maximal oxygen consumption were also measured. Associations between genotype and LDL-C were investigated using linear regression. Nearly one half (42.9%) of the female and 21.7% of the male subjects had a %BF that was above a healthy range. More than one quarter of the subjects had LDL-C values that were considered nonoptimal. Although the association was not significant when both sexes were combined, a significant association was observed between the SORT1 locus (GG: 2.46 ± 0.11 mmol·L(-1) vs. GT-TT: 2.06 ± 0.12 mmol·L(-1), p = 0.016) and LDL-C in male subjects, with genotype explaining 3.0% of the variability in LDL-C. A high prevalence of nonoptimal LDL-C exists in this young population even though it is otherwise fit and healthy. A significant association was found between LDL-C and the minor SORT1 allele in male subjects, with an effect size larger than previously reported in older populations. SORT1 is a valuable target for identifying individuals who would most benefit from early interventions to prevent cardiovascular disease.

ATP-binding cassette transporter G5 and G8 polymorphisms and several environmental factors with serum lipid levels

Background

The association of ATP-binding cassette (ABC) transporter single nucleotide polymorphisms (SNPs) and serum lipid profiles is inconsistent. The present study was undertaken to detect the association of ABCG5/G8 SNPs and several environmental factors with serum lipid levels.

Methodology/Principal Findings

Genotyping of the ABCG5 (rs4131229 and rs6720173) and ABCG8 (rs3806471 and rs4148211) SNPs was performed in 719 unrelated subjects of Mulao nationality and 782 participants of Han nationality. There were no differences in the genotypic and allelic frequencies of four SNPs between the two ethnic groups besides the genotypic frequencies of rs4131229 SNP in Han. The levels of triglyceride (TG), apolipoprotein (Apo) A1, and ApoA1/ApoB ratio (rs4131229); low-density lipoprotein cholesterol (LDL-C) and ApoB (rs6720173); high-density lipoprotein cholesterol (HDL-C), ApoA1, ApoB, and ApoA1/ApoB ratio (rs3806471); and HDL-C, ApoA1, and ApoA1/ApoB ratio (rs4148211) in Han were different among their genotypes (P<0.05–0.001). The levels of LDL-C (rs6720173) and ApoA1 (rs3806471) in Mulao were also different among their genotypes (P<0.05 for each). The levels of TC, TG, HDL-C, ApoA1, and ApoA1/ApoB ratio (rs4131229); LDL-C and ApoB (rs6720173); HDL-C, ApoA1, and ApoA1/ApoB ratio (rs3806471); and TG, HDL-C, ApoA1, and ApoA1/ApoB ratio (rs4148211) in Han males; and ApoA1/ApoB ratio (rs4131229); LDL-C, ApoB, and ApoA1/ApoB ratio (rs3806471); HDL-C, ApoA1, and ApoA1/ApoB ratio (rs4148211) in Han females were different between the genotypes (P<0.05–0.001). The levels of LDL-C in Mulao females were also different between GG and GC/CC genotypes of rs6720173 (P<0.05). The correlation between serum lipid parameters and genotypes of four SNPs was observed in Han, especially in Han males. Serum lipid parameters were also correlated with several environmental factors.

Conclusions

The associations of four ABCG5/G8 SNPs and serum lipid levels are different between the Mulao and Han populations, or between males and females, suggesting that there may be a racial/ethnic- and/or sex-specific association between ABCG5/G8 SNPs and some serum lipid parameters.

Heritability and genetic correlations explained by common SNPs for metabolic syndrome traits

We used a bivariate (multivariate) linear mixed-effects model to estimate the narrow-sense heritability (h²) and heritability explained by the common SNPs (h_g²) for several metabolic syndrome (MetS) traits and the genetic correlation between pairs of traits for the Atherosclerosis Risk in Communities (ARIC) genome-wide association study (GWAS) population. MetS traits included body-mass index (BMI), waist-to-hip ratio (WHR), systolic blood pressure (SBP), fasting glucose (GLU), fasting insulin (INS), fasting trigylcerides (TG), and fasting high-density lipoprotein (HDL). We found the percentage of h² accounted for by common SNPs to be 58% of h² for height, 41% for BMI, 46% for WHR, 30% for GLU, 39% for INS, 34% for TG, 25% for HDL, and 80% for SBP. We confirmed prior reports for height and BMI using the ARIC population and independently in the Framingham Heart Study (FHS) population. We demonstrated that the multivariate model supported large genetic correlations between BMI and WHR and between TG and HDL. We also showed that the genetic correlations between the MetS traits are directly proportional to the phenotypic correlations.

The narrow-sense heritability of a trait such as body-mass index is a measure of the variability of the trait between people that is accounted for by their additive genetic differences. Knowledge of these genetic differences provides insight into biological mechanisms and hence treatments for diseases. Genome-wide association studies (GWAS) survey a large set of genetic markers common to the population. They have identified several single markers that are associated with traits and diseases. However, these markers do not seem to account for all of the known narrow-sense heritability. Here we used a recently developed model to quantify the genetic information contained in GWAS for single traits and shared between traits. We specifically investigated metabolic syndrome traits that are associated with type 2 diabetes and heart disease, and we found that for the majority of these traits much of the previously unaccounted for heritability is contained within common markers surveyed in GWAS. We also computed the genetic correlation between traits, which is a measure of the genetic components shared by traits. We found that the genetic correlation between these traits could be predicted from their phenotypic correlation.

Carbohydrate intake modulates the effect of the ABCA1-R230C variant on HDL cholesterol concentrations in premenopausal women

The R230C variant of the ATP-binding cassette transporter A1 (ABCA1) gene has been consistently associated with decreased HDL-cholesterol (HDL-C) concentrations in several studies in the Mexican mestizo population. However, information on how diet composition modifies the effect of the ABCA1-R230C variant on HDL-C concentrations is very scarce. The aim of the present study was to analyze whether the effect of ABCA1-R230C on HDL-C concentrations is modulated by dietary factors in a nationwide population sample of 3591 adults from the National Health and Nutrition Survey conducted by the State's Employees' Social Security and Social Services Institute. All participants answered a validated questionnaire to assess health status and weekly food consumption. Fasting blood samples were drawn for biochemical analysis and DNA extraction, and the ABCA1-R230C variant was genotyped using TaqMan assays. Statistical analyses consisted of simple linear and multiple regression modeling adjusting for age, BMI, smoking, and alcohol consumption. The overall C risk allele frequency was 9.3% and the variant was significantly associated with low HDL-C concentrations in both sexes. A significant negative correlation between carbohydrate consumption and HDL-C concentrations was observed in women bearing the R230C variant (P = 0.021) and a significant gene-diet interaction was found only in premenopausal women (P = 0.037). In conclusion, the effect of the ABCA1-R230C gene variant on HDL-C concentrations is modulated by carbohydrate intake in premenopausal women. This finding may help design optimized dietary interventions according to sex and ABCA1-R230C genotype.

Association of the TRIB1 tribbles homolog 1 gene rs17321515 A>G polymorphism and serum lipid levels in the Mulao and Han populations

Background

The association of rs17321515 single nucleotide polymorphism (SNP) near TRIB1 gene and serum lipid profiles has never been studied in the Chinese population. Therefore, the present study was undertaken to detect the association of rs17321515 SNP and several environmental factors on serum lipid levels in the Mulao and Han populations.

Methods

A total of 639 unrelated subjects of Mulao nationality and 644 participants of Han nationality were randomly selected from our previous stratified randomized cluster samples. Genotypes of the TRIB1 rs17321515 A>G SNP were determined via polymerase chain reaction and restriction fragment length polymorphism, and then confirmed by direct sequencing.

Results

Serum apolipoprotein (Apo) B levels were higher in Mulao than in Han (P < 0.05). There were no differences in the genotypic and allelic frequencies between the two ethnic groups (P > 0.05). High- and low-density lipoprotein cholesterol (HDL-C and LDL-C) levels in Han were different among the genotypes (P < 0.05 for each), the subjects with AG/GG genotypes had higher HDL-C and LDL-C levels than the subjects with AA genotype. Total cholesterol (TC), HDL-C, LDL-C, ApoA1 and ApoB levels in Han males were different among the genotypes (P < 0.05-0.001), the G carriers had higher TC, HDL-C, LDL-C, ApoA1 and ApoB levels than the G noncarriers. HDL-C levels in Mulao males were different among the genotypes (P < 0.05), the G carriers had lower HDL-C levels than the G noncarriers. Serum HDL-C and LDL-C levels in both ethnic groups and TG levels in Han were correlated with the genotypes or alleles (P < 0.05-0.01). TG and HDL-C levels in Mulao males and TG, HDL-C, LDL-C and ApoA1 levels in Han males were correlated with genotypes or alleles (P < 0.05-0.001). TG and ApoA1 levels in Han females were associated with genotypes (P < 0.05 for each). Serum lipid parameters were also associated with several environmental factors in both ethnic groups.

Conclusions

The associations of TRIB1 rs17321515 SNP and serum lipid levels are different between the Mulao and Han populations. These discrepancies might partly result from different TRIB1 gene-environmental interactions in both ethnic groups.

Association of apolipoprotein A5 gene polymorphisms and serum lipid levels

BACKGROUND AND AIMS

Apolipoprotein (APO) A5 gene polymorphisms have been associated with increased plasma triglyceride (TG), but the results are inconsistent. The present study was undertaken to detect the APOA5 gene polymorphisms and their associations with lipid profiles in the Guangxi Hei Yi Zhuang and Han populations.

METHODS AND RESULTS

Genotyping of the APOA5 -1131T>C, c.553G>T and c.457G>A was performed in 490 subjects of Hei Yi Zhuang and 540 participants of Han Chinese aged 15-89 years. The -1131C allele frequency was higher in high total cholesterol (TC) than in normal TC subgroups in both the ethnic groups (P<0.05). The c.553T allele frequency was higher in high TG than in normal TG subgroups (P<0.01), in high APOB than in normal APOB subgroups in Hei Yi Zhuang (P<0.05), or in females than in males in Han (P<0.01). The c.457A allele frequency in Han was higher in high TG than in normal TG subgroups, in low APOA1 than in normal APOA1 subgroups, in males than in females, or in normal APOB than in high APOB subgroups (P<0.05-0.01). The levels of TC, low-density lipoprotein cholesterol and APOB in Hei Yi Zhuang were correlated with -1131T>C genotype or allele, and the levels of TG were associated with c.553G>T genotype (P<0.05). The levels of TG, APOA1 and APOB in Han were correlated with c.457G>A genotype or allele, and the levels of TC were associated with -1131T>C allele (P<0.05).

CONCLUSIONS

The differences in the lipid profiles between the two ethnic groups might partly result from different APOA5 gene-environmental interactions.

Association of the GALNT2 gene polymorphisms and several environmental factors with serum lipid levels in the Mulao and Han populations

BACKGROUND

The association of UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase 2 gene (GALNT2) single nucleotide polymorphisms (SNPs) and serum lipid profiles in the general population is not well known. The present study was undertaken to detect the association of GALNT2 polymorphisms and several environmental factors with serum lipid levels in the Guangxi Mulao and Han populations.

METHOD

A total of 775 subjects of Mulao nationality and 699 participants of Han nationality were randomly selected from our stratified randomized cluster samples. Genotyping of the GALNT2 rs2144300 and rs4846914 SNPs was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

RESULTS

There were no significant differences in the genotypic and allelic frequencies of both SNPs between the two ethnic groups, or between the males and females. The subjects with TT genotype of rs2144300 in Mulao had lower serum triglyceride (TG) levels than the subjects with CC genotype in females (P < 0.01). The participants with CT/TT genotype of rs2144300 in Han had lower TG and apolipoprotein (Apo) B levels, and higher high-density lipoprotein cholesterol (HDL-C), ApoA1 levels and the ratio of ApoA1 to ApoB in males; and higher low-density lipoprotein cholesterol (LDL-C) and ApoB levels in females than the participants with CC genotype (P < 0.05-0.001). The individuals with GA/AA genotype of rs4846914 in Mulao had higher total cholesterol (TC) and LDL-C levels than the individuals with GG genotype in males (P < 0.05 for each). The subjects with AA genotype of rs4846914 in Han had higher LDL-C and ApoB levels, and lower HDL-C levels and the ratio of ApoA1 to ApoB than the subjects with GG genotype (P < 0.05 for each). The levels of TC in Mulao were correlated with the genotypes of rs4846914 in males (P < 0.05). The levels of ApoA1 in Han were correlated with the genotypes of both SNPs, and the levels of HDL-C and ApoB and the ratio of ApoA1 to ApoB were associated with the genotypes of rs2144300 in males (P < 0.05-0.001). The levels of LDL-C in Han were correlated with the genotypes of rs4846914 in females (P < 0.05). Serum lipid parameters were also correlated with several enviromental factors.

CONCLUSIONS

The associations of both GALNT2 rs2144300 and rs4846914 SNPs and serum lipid levels are different in the Mulao and Han populations. These discrepancies might partly result from different GALNT2 gene-enviromental interactions.

The role of common variants of the cholesteryl ester transfer protein gene in left main coronary artery disease

BACKGROUND

The cholesteryl ester transfer protein (CETP) has a central role in the lipid metabolism and therefore may alter the susceptibility to atherosclerosis.

METHODS

The DNA of 471 subjects [133 subjects with angiographically documented left main coronary artery disease (LMCAD), 241 subjects with more peripheral coronary artery disease (MPCAD) and 97 subjects self reported healthy (Controls)] was analyzed for the frequency of TaqIB and I405V polymorphisms in the gene coding CETP.

RESULTS

There is no significant difference in CETP allele frequency or genotype distribution among LMCAD and MPCAD patients although there is statistical difference between LMCAD and Controls (p = 0.001). Specifically, patients with LMCAD and B1B1 genotype of TaqIB polymorphism were more frequent present compared to Controls (33.8% vs 22.9%, respectively). The frequency of B2B2 genotype was 3 times lower in the LMCAD group compared to Controls (10.5% vs 30.2%, respectively). In the LMCAD group the frequency of B1 allele compared to Controls was higher (62% vs 46%, respectively, p = 0.001). The relationship between TaqIB gene polymorphism and the LMCAD was independent of lipid profile, with the exception of apolipoprotein A.

CONCLUSIONS

These findings indicate that the TaqIB polymorphism may have potential importance in screening individuals at high risk for developing CAD. However, this polymorphism cannot distinguish between LMCAD and MPCAD. Further prospective investigations in larger populations are required to confirm these findings.

Familial concordance of metabolic syndrome in Korean population--Korean National Health and Nutrition Examination Survey 2005

AIMS

To investigate the familial concordance of metabolic syndrome and its components in a nationally representative survey in Korean.

METHODS

We used data from the Korean National Health and Nutrition Examination Survey (KNHANES), a nationwide survey examining the general health and nutritional status of the Korean people. We enrolled 1641 married couples and 1527 parents-1342 offspring.

RESULTS

Prevalence of the metabolic syndrome was 17.1% for husbands, 11.7% for wives, 14.3% for parents, and 7.2% for offspring. After adjustment for age, there were strong positive correlations between family members for the metabolic variables. Compared with husbands whose wives did not have metabolic syndrome, adjusted odds ratio in husbands whose wives had metabolic syndrome was 1.43 (95% CI: 1.10-1.87) for the risk of having metabolic syndrome. Similarly, wives whose husbands had metabolic syndrome had 1.41 (95% CI: 1.08-1.84) times higher risk of having metabolic syndrome. Compared with children whose parents did not have metabolic syndrome, adjusted odds ratio in children with at least one parent with the metabolic syndrome was 2.56 (95% CI: 1.09-5.98) for the metabolic syndrome.

CONCLUSIONS

Our study revealed that there is significant familial concordance for metabolic syndrome and its components in Korean families.

Environmental factors, familial aggregation and heritability of total cholesterol, low density lipoprotein-cholesterol and high density lipoprotein-cholesterol in a Brazilian population assisted by the Family Doctor Program

OBJECTIVES

To estimate familial aggregation and the heritability of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) in families assisted by the Family Doctor Program in a Brazilian city, and to evaluate associations between some environmental factors and familial aggregation of these lipids.

STUDY DESIGN

Cross-sectional familial study.

METHODS

The association of lipids with sociodemographic factors, lifestyle factors and comorbidities (e.g. physical activity, alcohol consumption, smoking, hypertension, impaired glucose tolerance, body mass index) was estimated using linear models and generalized estimating equations. Correlation of TC, LDL-C and HDL-C between pairs of relatives was estimated with the familial correlation procedure, and heritability was estimated with the ASSOC procedure.

RESULTS

All associations were statistically significant. There was familial aggregation of TC (parent/offspring, r=0.33; sibling/sibling, r=0.37), LDL-C (parent/offspring, r=0.29; sibling/sibling, r=0.37) and HDL-C (parent/offspring, r=0.25; sibling/sibling, r=0.48), but less than 3%, 6% and 14%, respectively, which was explained by lifestyle factors. Correlation between pairs with genetic sharing (parent/offspring and sibling/sibling) was higher than that observed between father and mother. Heritability estimates ranged between 0.32 (HDL-C) and 0.50 (TC). Similar results were found for the two approaches used to estimate the contribution of genetic and environmental factors in the correlation of TC, LDL-C and HDL-C between the family pairs.

CONCLUSION

The results showed that there is familial aggregation of TC, LDL-C and HDL-C, and point to the predominance of genetic factors because little influence of environmental variables was found.

Low density lipoprotein receptor gene Ava II polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

BACKGROUND

Several common genetic polymorphisms in the low density lipoprotein receptor (LDL-R) gene have associated with modifications of serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels, but the results are not consistent in different populations. Bai Ku Yao is a special subgroup of the Yao minority in China. The present study was undertaken to detect the association of LDL-R gene Ava Ⅱ polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

METHODS

A total of 1024 subjects of Bai Ku Yao and 792 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the LDL-R gene Ava Ⅱ polymorphism was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

RESULTS

The levels of serum TC, high density lipoprotein cholesterol (HDL-C), LDL-C, apolipoprotein (Apo) A1 and the ratio of ApoA1 to ApoB were lower in Bai Ku Yao than in Han (P < 0.01 for all). The frequency of A⁻ and A+ alleles was 65.5% and 34.5% in Bai Ku Yao, and 80.7% and 19.3% in Han (P < 0.001); respectively. The frequency of A⁻A⁻, A⁻A+ and A+A+ genotypes was 42.6%, 45.9% and 11.5% in Bai Ku Yao, and 64.9%, 31.6% and 3.5% in Han (P < 0.001); respectively. There was also significant difference in the genotypic frequencies between males and females in Bai Ku Yao (P <0.05), and in the genotypic and allelic frequencies between normal LDL-C (≤ 3.20 mmol/L) and high LDL-C (> 3.20 mmol/L) subgroups in Bai Ku Yao (P < 0.05 for each) and between males and females in Han (P < 0.05 for each). The levels of LDL-C in males and TC and HDL-C in females were different among the three genotypes (P < 0.05 for all) in Bai Ku Yao, whereas the levels of HDL-C in males and HDL-C and ApoA1 in females were different among the three genotypes (P < 0.05-0.001) in Han. The subjects with A+A+ genotype had higher serum LDL-C, TC, HDL-C or ApoA1 levels than the subjects with A-A+ and A⁻A⁻ genotypes. Spearman rank correlation analysis revealed that the levels of LDL-C in Bai Ku Yao and HDL-C in Han were correlated with genotypes (P < 0.05 and P < 0.01; respectively).

CONCLUSIONS

The association of LDL-R gene Ava Ⅱ polymorphism and serum lipid levels is different between the Bai Ku Yao and Han populations. The discrepancy might partly result from different LDL-R gene Ava Ⅱ polymorphism or LDL-R gene-environmental interactions.

Genetic variant of V825I in the ATP-binding cassette transporter A1 gene and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

Background

Several genetic variants in the ATP-binding cassette transporter A1 (ABCA1) gene have associated with modifications of serum high-density lipoprotein cholesterol (HDL-C) levels and the susceptibility for coronary heart disease, but the findings are still controversial in diverse racial/ethnic groups. Bai Ku Yao is an isolated subgroup of the Yao minority in southern China. The present study was undertaken to detect the possible association of V825I (rs2066715) polymorphism in the ABCA1 gene and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

Methods

A total of 677 subjects of Bai Ku Yao and 646 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Polymerase chain reaction and restriction fragment length polymorphism assay combined with gel electrophoresis were performed for the genotyping of V825I variant, and then confirmed by direct sequencing.

Results

The levels of serum total cholesterol (TC), HDL-C, apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.01 for all). The frequency of G and A alleles was 57.4% and 42.6% in Bai Ku Yao, and 57.7% and 42.3% in Han (P > 0.05); respectively. The frequency of GG, GA and AA genotypes was 33.7%, 47.4% and 18.9% in Bai Ku Yao, and 33.4%, 48.6% and 18.0% in Han (P > 0.05); respectively. There was no difference in the genotypic and allelic frequencies between males and females in the both ethnic groups. The subjects with AA genotype in Bai Ku Yao had higher serum TC levels than the subjects with GG and GA genotypes (P < 0.05). The participants with AA genotype in Han had lower serum HDL-C and ApoAI levels than the participants with GG and GA genotypes (P < 0.05 for each), but these results were found in males but not in females. Multivariate linear regression analysis showed that the levels of TC in Bai Ku Yao and HDL-C and ApoAI in male Han were correlated with genotypes (P < 0.05 for all). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, and blood pressure in both ethnic groups (P < 0.05-0.001).

Conclusion

The present study suggests that the V825I polymorphism in the ABCA1 gene is associated with male serum HDL-C and ApoAI levels in the Han, and serum TC levels in the Bai Ku Yao populations. The difference in the association of V825I polymorphism and serum lipid levels between the two ethnic groups might partly result from different ABCA1 gene-enviromental interactions.