Several genetic polymorphisms interact with overweight/obesity to influence serum lipid levels

[－75 G/A Polymorphism of Apolipoprotein A1 Gene Promoter Region in Normal Pregnant Women and Patients With Gestational Diabetes Mellitus]

Objective

To investigate the －75 G/A single-nucleotide polymorphism in the promoter region of apolipoprotein A1 gene (apoA1) and its association with gestational diabetes mellitus (GDM) in pregnant women and to provide references for the exploration in the molecular genetic basis of GDM.

Methods

A total of 626 GDM patients and 1022 normal pregnant women, ie, the controls, were included in the study. The genotyping of apoA1 －75 G/A polymorphism was performed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and glucose (Glu) were measured by enzymatic methods. Plasma insulin (INS) was measured by chemiluminescence immunoassay. The protein levels of apoA1 and apoB were measured by the turbidimetric immunoassay.

Results

Allele frequencies of G and A were 0.718 and 0.282 in the GDM group and 0.713 and 0.287 in the control group, respectively. Distribution of the genotype frequencies was found to be in Hardy-Weinberg equilibrium in both the GDM and control groups. There was no significant difference in the frequencies of alleles G and A and the genotypes of apoA1 －75 G/A polymorphism between the GDM and the control group (P>0.05). In the GDM group, the carriers with the genotype AA were associated with significantly higher levels of TC, HDL-C, and apoA1 than those with genotypes GG and GA did (all P<0.05). After the GDM patients were divided into obese and non-obese subgroups, the genotype-related apoA1 variation was observed only in obese patients, while the genotype-related TC and HDL-C variations were evident in non-obese patients (P<0.05). In the control group, carriers of genotypes AA and GA had higher systolic blood pressure (SBP) and HDL-C than the carriers of genotype GG did (all P<0.05). Carriers of genotypes AA had significantly lower Glu levels than carriers of genotypes GG and GA did (P<0.05). The control subjects were further divided into subgroups according to their body mass index (BMI). Analysis of the subgroups showed that AA carriers were associated with higher SBP levels in the obese control women only, while lower Glu levels were evident in both obese and non-obese control women.

Conclusion

These results suggest that －75 G/A polymorphism in the apoA1 gene is not associated with GDM. However, the genetic variation is closed associated with the plasma apoA1, HDL-C, and TC levels in GDM patients and plasma HDL-C, Glu, and SBP levels in the control subjects. The apoA1 variant-associated lipids and SBP variation is BMI dependent in both groups.

ATP-binding cassette transporter G1 (ABCG1) polymorphisms in pregnant women with gestational diabetes mellitus

CONTEXT AND OBJECTIVES

Gestational diabetes mellitus (GDM) is the most common metabolic disorder in pregnancy, and it often leads to adverse pregnancy outcomes and seriously harms the health of mothers and infants. ATP-binding cassette transporter G1 (ABCG1) plays critical roles in high-density lipoprotein (HDL) metabolism and reverse cholesterol transport. This study was designed to explore the relevance of the ABCG1 polymorphisms in the atherometabolic risk in GDM.

STUDY DESIGN

The case-control population consists of 1504 subjects. The rs2234715 and rs57137919 single nucleotide polymorphisms (SNPs) were genotyped using PCR and DNA sequencing, and clinical and metabolic parameters were determined.

RESULTS

The genotype distributions of the two SNPs showed no difference between the GDM patient and control groups. However, the rs57137919 polymorphism was associated with total cholesterol (TC), and diastolic blood pressure (DBP) levels in patients with GDM. Moreover, subgroup analysis showed that this polymorphism was associated with ApoA1 and DBP levels in overweight/obese patients with GDM, while it was associated with TC, and gestational weight gain (GWG) in non-obese patients with GDM. Meanwhile, the rs2234715 polymorphism was found to be associated with neonatal birth height in non-obese patients with GDM.

CONCLUSIONS

The two polymorphisms in the ABCG1 have an influence on atherometabolic traits, GWG, and fetal growth in GDM, depending on the BMI of the patients.

PCSK9 Inhibitors in Cancer Patients Treated with Immune-Checkpoint Inhibitors to Reduce Cardiovascular Events: New Frontiers in Cardioncology

Cancer patients treated with immune checkpoint inhibitors (ICIs) are exposed to a high risk of atherosclerosis and cardiometabolic diseases due to systemic inflammatory conditions and immune-related atheroma destabilization. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key protein involved in metabolism of low-density lipoprotein (LDL) cholesterol. PCSK9 blocking agents are clinically available and involve monoclonal antibodies, and SiRNA reduces LDL levels in high-risk patients and atherosclerotic cardiovascular disease events in multiple patient cohorts. Moreover, PCSK9 induces peripheral immune tolerance (inhibition of cancer cell- immune recognition), reduces cardiac mitochondrial metabolism, and enhances cancer cell survival. The present review summarizes the potential benefits of PCSK9 inhibition through selective blocking antibodies and siRNA in patients with cancer, especially in those treated with ICIs therapies, in order to reduce atherosclerotic cardiovascular events and potentially improve ICIs-related anticancer functions.

Transcription factor 7-like 2 single nucleotide polymorphisms rs290487 and rs290481 are associated with dyslipidemia in the Balinese population

Background

Dyslipidemia is one of the major risks for the development of cardiovascular diseases which has been the leading cause of death in developing countries. Previously, common polymorphisms of the transcription factor 7-like 2 (TCF7L2) gene have been associated with altered lipid profiles. In this study, we investigated the associations of TCF7L2 SNPs, rs290487 and rs290481, with dyslipidemia and altered lipid profile in the Balinese.

Methods

A total of 565 subjects from four locations in the Bali Province, Indonesia, were recruited. Serum lipid concentrations (triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC)) were measured using standard protocol. SNP genotyping was done using the amplification refractory system mutation polymerase chain reaction (ARMS-PCR) method.

Results

We found the shifted major/minor allele frequencies of both SNPs (0.56 for rs290487 T allele, 0.53 for rs290481 T allele) in the Balinese, as compared to dbSNP. The rs290487 and rs290481 C alleles were significantly associated with dyslipidemia, particularly high TC and high LDL-C. These associations were independent of age, sex, population, obesity, diabetes mellitus, and high TyG index as a proxy for insulin resistance. The haplotype CC also showed similar association with these traits. Our findings indicate that TCF7L2 polymorphisms are associated with dyslipidemia and altered lipid profile in the Balinese.

Associations between TUBB-WWOX SNPs, their haplotypes, gene-gene, and gene-environment interactions and dyslipidemia

In this study, we investigated associations between single nucleotide polymorphisms (SNPs) in the tubulin beta class I (TUBB) and WW domain-containing oxidoreductase (WWOX) genes, gene-gene interactions, and gene-environment interactions and dyslipidemia in the Chinese Maonan ethnic group. Four SNPs (rs3132584, rs3130685, rs2222896, and rs2548861) were genotyped in unrelated subjects with normal lipid levels (864) or dyslipidemia (1129). While 5.0% of Maonan subjects carried the rs3132584TT genotype, none of the Chinese Han in Beijing subjects did. Allele and genotype frequencies differed between the normal and dyslipidemia groups for three SNPs (rs3132584, rs3130685, and rs2222896). rs2222896G allele carriers in the normal group had higher low-density lipoprotein cholesterol and lower high-density lipoprotein cholesterol levels. The rs3132584GG, rs3130685CC+TT, and rs2222896GG genotypes as well as the rs2222896G-rs2548861G and rs2222896G-rs2548861T haplotypes were associated with an elevated risk of dyslipidemia; the rs2222896A-rs2548861T and rs2222896A-rs2548861G haplotypes were associated with a reduced risk of dyslipidemia. Among the thirteen TUBB-WWOX interaction types identified, rs3132584T-rs3130685T-rs2222896G-rs2548861T increased the risk of dyslipidemia 1.371-fold. Fourteen two- to four-locus optimal interactive models for SNP-SNP, haplotype-haplotype, gene-gene, and gene-environment interactions exhibited synergistic or contrasting effects on dyslipidemia. Finally, the interaction between rs3132584 and rs2222896 increased the risk of dyslipidemia 2.548-fold and predicted hypertension.

A Common R219K Variant of ATP-Binding Cassette Transporter A1 Gene Alters Atherometabolic Traits in Pregnant Women With Gestational Diabetes Mellitus

BACKGROUND

ATP-binding cassette transporter A1 (ABCA1) has important roles in high-density lipoprotein (HDL) metabolism and reverse cholesterol transport, and is implicated in lipid-related disorders. Genetic variants are involved in the pathogenesis of gestational diabetes mellitus (GDM). The objective of this study was to investigate the association of rs2230806 (R219K), a single nucleotide polymorphism (SNP) in the lipid-related gene, with the risk of GDM and related traits.

METHODS

The SNP, rs2230806, was genotyped, and clinical and metabolic parameters were determined in 660 GDM patients and 1,097 control subjects. Genetic associations with related traits were also analyzed.

RESULTS

The genotype distributions were similar in GDM patients and normal controls. However, significant differences in the variables examined in the study subjects were noted across the three genotypes. The genotype at the rs2230806 polymorphism was significantly associated with HDL-cholesterol (HDL-C) levels and atherogenic index (AI) values in GDM patients and total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels in control subjects. Subgroup analysis showed that the polymorphism was associated with diastolic blood pressure, in addition to HDL-C levels and AI, in overweight/obese GDM patients, while it was associated with TC levels, AI, pre-pregnancy body mass index (BMI), and BMI at delivery in non-obese GDM patients. In addition, this polymorphism was associated with TC, LDL-C, and apoB levels in overweight/obese control subjects.

CONCLUSIONS

The rs2230806 polymorphism in the ABCA1 gene was associated with variations in atherometabolic traits in GDM patients, with characteristics of BMI dependency, but not with GDM. Our findings highlight a link between related phenotypes in women with GDM and genetic factors.

Model of genetic and environmental factors associated with type 2 diabetes mellitus in a Chinese Han population

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disorder which accounts for high morbidity and mortality due to complications like renal failure, amputations, cardiovascular disease, and cerebrovascular events.

METHODS

We collected medical reports, lifestyle details, and blood samples of individuals and used the polymerase chain reaction-ligase detection reaction method to genotype the SNPs, and a visit was conducted in August 2016 to obtain the incidence of Type 2 diabetes in the 2113 eligible people. To explore which genes and environmental factors are associated with type 2 diabetes mellitus in a Chinese Han population, we used elastic net to build a model, which is to explain which variables are strongly associated with T2DM, rather than predict the occurrence of T2DM.

RESULT

The genotype of the additive of rs964184, together with the history of hypertension, regular intake of meat and waist circumference, increased the risk of T2DM (adjusted OR = 2.38, p = 0.042; adjusted OR = 3.31, p < 0.001; adjusted OR = 1.05, p < 0.001). The TT genotype of the additive and recessive models of rs12654264, the CC genotype of the additive and dominant models of rs2065412, the TT genotype of the additive and dominant models of rs4149336, together with the degree of education, regular exercise, reduced the risk of T2DM (adjusted OR = 0.46, p = 0.017; adjusted OR = 0.53, p = 0.021; adjusted OR = 0.59, p = 0.021; adjusted OR = 0.57, p = 0.01; adjusted OR = 0.59, p = 0.021; adjusted OR = 0.57, p = 0.01; adjusted OR = 0.50, p = 0.007; adjusted OR = 0.80, p = 0.032) .

CONCLUSION

Eventually we identified a set of SNPs and environmental factors: rs5805 in the SLC12A3, rs12654264 in the HMGCR, rs2065412 and rs414936 in the ABCA1, rs96418 in the ZPR1 gene, waistline, degree of education, exercise frequency, hypertension, and the intake of meat. Although there was no interaction between these variables, people with two risk factors had a higher risk of T2DM than those only having one factor. These results provide the theoretical basis for gene and other risk factors screening to prevent T2DM.

Gene-environment interactions due to quantile-specific heritability of triglyceride and VLDL concentrations

"Quantile-dependent expressivity" is a dependence of genetic effects on whether the phenotype (e.g., triglycerides) is high or low relative to its distribution in the population. Quantile-specific offspring-parent regression slopes (β_OP) were estimated by quantile regression for 6227 offspring-parent pairs. Quantile-specific heritability (h²), estimated by 2β_OP/(1 + r_spouse), decreased 0.0047 ± 0.0007 (P = 2.9 × 10^-14) for each one-percent decrement in fasting triglyceride concentrations, i.e., h² ± SE were: 0.428 ± 0.059, 0.230 ± 0.030, 0.111 ± 0.015, 0.050 ± 0.016, and 0.033 ± 0.010 at the 90th, 75th, 50th, 25th, and 10th percentiles of the triglyceride distribution, respectively. Consistent with quantile-dependent expressivity, 11 drug studies report smaller genotype differences at lower (post-treatment) than higher (pre-treatment) triglyceride concentrations. This meant genotype-specific triglyceride changes could not move in parallel when triglycerides were decreased pharmacologically, so that subtracting pre-treatment from post-treatment triglyceride levels necessarily created a greater triglyceride decrease for the genotype with a higher pre-treatment value (purported precision-medicine genetic markers). In addition, sixty-five purported gene-environment interactions were found to be potentially attributable to triglyceride's quantile-dependent expressivity, including gene-adiposity (APOA5, APOB, APOE, GCKR, IRS-1, LPL, MTHFR, PCSK9, PNPLA3, PPARγ2), gene-exercise (APOA1, APOA2, LPL), gene-diet (APOA5, APOE, INSIG2, LPL, MYB, NXPH1, PER2, TNFA), gene-alcohol (ALDH2, APOA5, APOC3, CETP, LPL), gene-smoking (APOC3, CYBA, LPL, USF1), gene-pregnancy (LPL), and gene-insulin resistance interactions (APOE, LPL).

Differential metabolic and multi-tissue transcriptomic responses to fructose consumption among genetically diverse mice

Understanding how individuals react differently to the same treatment is a major concern in precision medicine. Metabolic challenges such as the one posed by high fructose intake are important determinants of disease mechanisms. We embarked on studies to determine how fructose affects differential metabolic dysfunctions across genetically dissimilar mice, namely, C57BL/6 J (B6), DBA/2 J (DBA) and FVB/NJ (FVB), by integrating physiological and gene regulatory mechanisms. We report that fructose has strain-specific effects, involving tissue-specific gene regulatory cascades in hypothalamus, liver, and white adipose tissues. DBA mice showed the largest numbers of genes associated with adiposity, congruent with their highest susceptibility to adiposity gain and glucose intolerance across the three tissues. In contrast, B6 and FVB mainly exhibited cholesterol phenotypes, accompanying the largest number of adipose genes correlating with total cholesterol in B6, and liver genes correlating with LDL in FVB mice. Tissue-specific network modeling predicted strain-and tissue-specific regulators such as Fgf21 (DBA) and Lss (B6), which were subsequently validated in primary hepatocytes. Strain-specific fructose-responsive genes revealed susceptibility for human diseases such that genes in liver and adipose tissue in DBA showed strong enrichment for human type 2 diabetes and obesity traits. Liver and adipose genes in FVB were mostly related to lipid traits, and liver and adipose genes in B6 showed relevance to most cardiometabolic traits tested. Our results show that fructose induces gene regulatory pathways that are tissue specific and dependent on the genetic make-up, which may underlie interindividual variability in cardiometabolic responses to high fructose consumption.

Pleiotropic association of LIPC variants with lipid and urinary 8-hydroxy deoxyguanosine levels in a Taiwanese population

BACKGROUND

Hepatic lipase (HL, encoded by LIPC) is a glycoprotein primarily synthesized and secreted by hepatocytes. Previous studies had demonstrated that HL is crucial for reverse cholesterol transport and affects the metabolism, composition, and level of several lipoproteins. In current study, we investigated the association of LIPC (Lipase C, Hepatic Type) variants with circulating and urinary biomarker levels by using subgroup and mediation analyses.

METHODS

A total of 572 participants from Taiwan were genotyped for three LIPC single nucleotide polymorphisms (SNPs) by using TaqMan assay. Fasting levels of glucose, lipid profile, inflammation markers, urine creatinine and 8-hydroxy deoxyguanosine (8-OHdG) were measured. The chi-square test, 2-sample t test and Analysis of variance (ANOVA) were used to examine differences among variables and genotype frequencies.

RESULTS

SNPs rs2043085 and rs1532085 were significantly associated with urinary 8-OHdG levels, whereas all three SNPs were more significantly associated with Triglycerides (TG) or HDL-cholesterol (HDL-C) levels after additional adjustment for HDL-C or TG levels, respectively. Subgroup analyses revealed that the association of the LIPC SNPs with the levels of serum TG, HDL-C, and urinary 8-OHdG were predominantly observed in the men but not in the women. Differential associations of the LIPC SNPs with various lipid levels were observed in participants with different adiposity statuses. Mediation analyses indicated that TG levels acted as a suppressor masking the association of the LIPC genotypes with HDL-C levels, particularly in the men (Sobel test, all P < 0.01).

CONCLUSION

Our data revealed that interaction and suppression effects mediated the pleiotropic association of the LIPC variants. The effects of the LIPC SNPs depended on sex, adiposity status, and TG levels. Thus, our findings can provide a method for identifying high-risk populations of cardiovascular diseases for clinical diagnosis.

Plausible relationship between homocysteine and obesity risk via MTHFR gene: a meta-analysis of 38,317 individuals implementing Mendelian randomization

OBJECTIVE

Numerous studies have explored the role of methylenetetrahydrofolate reductase gene (MTHFR) C677T polymorphism and homocysteine (Hcy) concentration in obesity, but the results are inconsistent. Hence, we performed a meta-analysis implementing Mendelian randomization approach to test the assumption that the increased Hcy concentration is plausibly related to the elevated risk of obesity.

METHODS

Eligible studies were selected based on several inclusion and exclusion criteria. Correlations between MTHFR C677T and obesity risk, MTHFR C677T and Hcy concentration in obesity, Hcy concentration, and obesity were estimated by ORs, effect size and standard mean difference with their corresponding 95% CIs, respectively. Furthermore, Mendelian randomization analysis was performed to estimate the relationship between Hcy level and obesity.

RESULTS

Consequently, this meta-analysis implemented with Mendelian randomization approach was conducted among 8,622 cases and 29,695 controls. The results indicated that MTHFR C677T is associated with an increased risk of obesity (for T vs C: OR=1.06, 95% CI=1.02-1.10; for TT vs CC: OR=1.13, 95% CI=1.03-1.24). Moreover, in obese subjects, the pooled Hcy concentration in individuals of TT genotype was 2.91 mmol/L (95% CI: 0.27-5.55) higher than that in individuals of CC genotype. Furthermore, the pooled Hcy concentration in subjects with obesity was 0.74 mmol/L (95% CI: 0.36-1.12) higher than that in controls. The evaluated plausible OR associated with obesity was 1.23 for 5 μmol/L Hcy level increase.

CONCLUSIONS

Through this meta-analysis, we emphasize a strong relationship between Hcy level and obesity by virtue of MTHFR C677T polymorphism.

Multivariate analysis of genomics data to identify potential pleiotropic genes for type 2 diabetes, obesity and dyslipidemia using Meta-CCA and gene-based approach

Previous studies have demonstrated the genetic correlations between type 2 diabetes, obesity and dyslipidemia, and indicated that many genes have pleiotropic effects on them. However, these pleiotropic genes have not been well-defined. It is essential to identify pleiotropic genes using systematic approaches because systematically analyzing correlated traits is an effective way to enhance their statistical power. To identify potential pleiotropic genes for these three disorders, we performed a systematic analysis by incorporating GWAS (genome-wide associated study) datasets of six correlated traits related to type 2 diabetes, obesity and dyslipidemia using Meta-CCA (meta-analysis using canonical correlation analysis). Meta-CCA is an emerging method to systematically identify potential pleiotropic genes using GWAS summary statistics of multiple correlated traits. 2,720 genes were identified as significant genes after multiple testing (Bonferroni corrected p value < 0.05). Further, to refine the identified genes, we tested their relationship to the six correlated traits using VEGAS-2 (versatile gene-based association study-2). Only the genes significantly associated (Bonferroni corrected p value < 0.05) with more than one trait were kept. Finally, 25 genes (including two confirmed pleiotropic genes and eleven novel pleiotropic genes) were identified as potential pleiotropic genes. They were enriched in 5 pathways including the statin pathway and the PPAR (peroxisome proliferator-activated receptor) Alpha pathway. In summary, our study identified potential pleiotropic genes and pathways of type 2 diabetes, obesity and dyslipidemia, which may shed light on the common biological etiology and pathogenesis of these three disorders and provide promising insights for new therapies.

Interactions among genes involved in reverse cholesterol transport and in the response to environmental factors in dyslipidemia in subjects from the Xinjiang rural area

Gene-gene and gene-environment interactions may be partially responsible for dyslipidemia, but studies investigating interactions in the reverse cholesterol transport system (RCT) are limited. We explored these interactions in a Xinjiang rural population by genotyping five SNPs using SNPShot technique in APOA1, ABCA1, and LCAT, which are involved in the RCT (690 patients, 743 controls). We conducted unconditional logistical regression analysis to evaluate associations and generalized multifactor dimensionality reduction to evaluate interactions. Results revealed significant differences in rs670 and rs2292318 allele frequencies between cases and controls (P<0.025). rs670 G allele carriers were more likely to develop dyslipidemia than A allele carriers (OR = 1.315, OR 95% CI: 1.067–2.620; P = 0.010). rs2292318 T allele carriers were more likely to develop dyslipidemia than A allele carriers (OR = 1.264, OR 95% CI: 1.037–1.541; P = 0.020). Gene-gene interaction model APOA1rs670-ABCA1rs1800976-ABCA1rs4149313-LCATrs1109166 (P = 0.0107) and gene-environment interaction model ABCA1rs1800976-ABCA1rs4149313-LCATrs1109166-obesity-smoking were optimal dyslipidemia predictors (P = 0.0107) and can interact (4). Differences in A-C-A-C-A and G-G-G-T-G haplotype frequencies were observed (P<0.05). Serum lipid profiles could be partly attributed to RCT gene polymorphisms. Thus, dyslipidemia is influenced by APOA1, ABCA1, LCAT, environmental factors, and their interactions.

Influence of the C677T Polymorphism of the MTHFR Gene on Oxidative Stress in Women With Overweight or Obesity: Response to a Dietary Folate Intervention

The C677T polymorphism of the methylenetetrahydrofolate reductase gene (MTHFR) is related to folate metabolism and can alter the levels of biochemical markers.Objective: Investigate the influence of the MTHFR C677T polymorphism on the effects of a dietary folate intervention on oxidative stress in women with overweight or obesity.Methods: Forty-eight adult women with overweight or obesity were subjected to a 24-hour dietary recall, anthropometric measurements, biochemical analysis, and genotyping of the MTHFR C677T polymorphism. They were allocated by convenience sampling to 2 groups, which received 300 g of folate-rich vegetables containing 191 µg/d (Group 1) (n = 24) or 95 µg/d (Group 2) (n = 24) of folate for 8 weeks.Results: The dietary intervention increased the serum folic acid levels in the 2 analyzed groups. The intervention with 191 µg/d of folate led to relevant results in terms of homocysteine levels (p = 0.0005) and total antioxidant capacity (p = 0.0261); the effect was larger among carriers of the TT genotype.Conclusions: The study demonstrated the beneficial effect of folate intake in terms of a TAC elevation for the CC and TT genotypes of the MTHFR C677T polymorphism, an increase in folic acid levels for all genotypes, and a reduction in the Hcy levels for the TT genotype in response to an intervention consisting of an intake of 191 µg/d of folate supplied by vegetables.

Genetic variants of SLC12A3 modulate serum lipid profiles in a group of Mongolian pedigree population

Background

The serum lipid profile, including LDL-C level, is associated with hypertension which is the major cause of cerebrovascular disease (CVD) amounting 30% of global death rate. Previous work also demonstrated important roles of genetic variants of SLC12A3 gene on human CVD, hypertension and other diseases in Mongolian population. However, the relationship between SLC12A3 gene polymorphisms on individuals’ lipid profile is still unknown.

Methods

A panel of 15 SNPs of SLC12A3 gene was genotyped within a 424 Mongolians pedigree cohort. The associations between SLC12A3 polymorphisms and four lipid profiles were analyzed by family-based association test (FBAT) and confirmed with haplotype analysis.

Results

From both single site and haplotype analyses, the results demonstrated a close relationship between SLC12A3 polymorphisms and LDL-C level. Two SNPs, rs5803 and rs711746 showed significant associations with individuals’ serum LDL-C level (z = − 2.08, P_-e = 0.038; z = 2.09, P_-e = 0.023, respectively), and distribution of haplotypes constructed by two SNPs also associated with participants’ serum LDL-C level, significantly (Global Chi² = 9.06 df = 3, P = 0.028).

Conclusion

Our results demonstrated the importance of SLC12A3 polymorphisms in individuals’ difference about their serum lipid profiles, thereby providing evidence that the genetic variants may contribute to CVD development via modulating person’s LDL-C level and blood pressure, in certain contexts.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0737-1) contains supplementary material, which is available to authorized users.

Evaluation of PCSK9 levels and its genetic polymorphisms in women with polycystic ovary syndrome

Dyslipidemia is one of the common metabolic disorders in Polycystic Ovary Syndrome (PCOS). Proprotein convertase subtilisin kexin type 9 (PCSK9) is a new component of lipid metabolism and correlated to the development of dyslipidemia and atherosclerosis. This protein acts by preventing the recycling of LDL receptors (LDL-r) back to the cell surface and thus generates higher levels of LDLc. The objective of this study was to evaluate the PCSK9 polymorphisms rs505151 (c.2009A>G), rs562556 (c.1420A>G) and rs11206510 (T>C) and plasma PCSK9 levels in PCOS. A group of women with PCOS (n=97), and a group of healthy women (control, n=99) were selected. Biochemical parameters were determined by using Vitros system and polymorphisms were assessed by TaqMan SNP Genotyping Assays. Plasma PCSK9 levels or PCSK9 polymorphisms were not associated with PCOS. The genotype rs11206510TT was associated with higher levels of PCSK9 in both groups. The population investigated (PCOS+control groups) with the rs505151AA genotype presented higher HDLc levels. The GG genotype regarding rs562556 polymorphism was associated with higher HDLc in PCOS group, while the AA genotype carriers had higher plasma testosterone levels when evaluated all women in a same group. The results were the same by comparing recessive and dominant model despite PCOS or both groups altogether. Our results suggest that PCSK9 is not altered specifically in PCOS, but it could be associated with in lipid and androgen metabolism in Brazilian women.

SLC12A3 variants modulate LDL cholesterol levels in the Mongolian population

Background

Abnormalities in lipid metabolism are crucial factors in the pathogenesis of cardiovascular disease (CVD). Variants of many genes have been verified to confer risk for lipid metabolism abnormalities. However, the relationship between genetic variants of the NCC-encoding SLC12A3 gene and lipid metabolism in the Mongolian population remains unclear. In the present study, we aimed to elucidate the effects of SLC12A3 variants on Mongolian lipid metabolism, including total cholesterol (TCHO), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c).

Methods

A randomly selected population of Mongolians (n = 331) from China underwent clinical testing. An ANOVA test, Kruskal-Wallis H test (K-W test) and haplotype analysis were used to evaluate the association between the levels of lipids (TCHO, TG, LDL-c, and HDL-c) and polymorphisms in SLC12A3 loci.

Results

We identified three single nucleotide polymorphisms (SNPs) rs5803, rs2010501 and rs711746 in the SLC12A3 gene that were significantly associated with an individual’s serum LDL-c level. Haplotypes combining these SNPs also showed the same trend (all p values < 0.01). Furthermore, the influence of SLC12A3 genetic polymorphisms on differences in individual serum LDL-c levels remained significant, even after we controlled gender, and demographic and other non-genetic factors.

Conclusion

These results suggest that variants of the SLC12A3 gene confer susceptibility to the abnormal serum LDL-c level in the Mongolian population.

Effect of ATP-binding Cassette Transporter A1 (ABCA1) Gene Polymorphisms on Plasma Lipid Variables and Common Demographic Parameters in Greek Nurses

Objective:

The present study is on line with our previous studies evaluating the influence of ATP-binding cassette transporter A1 (ABCA1) gene polymorphisms on the lipid variables of Greek student-nurses. The current study was undertaken to (1) estimate the influence of variant(s) such as rs2066715 (V825I), R219K, R1587K, I883M of ABCA1 gene on lipid variables and (2) evaluate the effect of all four ABCA1 polymorphisms on common demographic parameters.

Methods:

The study population involved 432 unrelated nurses (86 men) who were genotyped for ABCA1 polymorphisms and correlated according to lipid variables [total cholesterol (TC), triglycerides (TGs), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and apolipoprotein (apo) A] and demographic parameters (age, gender, BMI, waist circumference).

Results:

According to lipid variables concentration there was no difference between genotypes and alleles of V825I, R219K and I883M polymorphisms. The LDL-C concentration was 13% lower in RR compared with RK genotype (100.7 vs. 113.9 mg/dl, p=0.013) of R1587K gene polymorphism. In regression analysis the effects of age, gender and only R1587K gene polymorphism on LDL-C concentrations were proved significant. Additionally, LDL-C was increased (by 1.29 mg/dl on average) by every year of increase of age. Moreover, females had lower LDL-C concentrations as compared with males.

Conclusion:

Findings suggested that only R1587K polymorphism of ABCA1 gene was associated with lipid variables, age, and gender of Greek nurses. These findings may be helpful in assessing the risk factors for premature coronary heart disease and distinct individuals with lower/higher atherosclerotic burden.

Gender-specific interactions of MTHFR C677T and MTRR A66G polymorphisms with overweight/obesity on serum lipid levels in a Chinese Han population

Background

Little is known regarding the interactions of methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms with overweight/obesity on serum lipid profiles. The aim of the current study was to explore interactions between the two polymorphisms and overweight/obesity on four common lipid levels in a Chinese Han population and further to evaluate whether these interactions exhibit gender-specificity.

Methods

A total of 2239 participants (750 females and 1489 males) were enrolled into this study. The genotypes of the MTHFR C677T and MTRR A66G were determined by a TaqMan assay. Overweight and obesity were defined as a body mass index between 24 and 27.99 and ≥ 28 kg/m², respectively. The interactions were examined by factorial design covariance analysis, and further multiple comparisons were conducted by Bonferroni correction.

Results

There was no significant difference in the genotypic and allelic frequencies between females and males (MTHFR 677 T allele: 54.47 % for females and 54.40 % for males; MTRR 66G allele: 24.73 % for females and 24.71 % for males). Interaction between the MTHFR C677T polymorphism and overweight/obesity on serum triglyceride levels, and interaction between the MTRR A66G polymorphism and overweight/obesity on serum high-density lipoprotein cholesterol levels were detected in women (P = 0.015 and P = 0.056, respectively). For female subjects with overweight/obesity, the serum triglyceride levels in MTHFR 677TT genotype [1.09 (0.78–1.50) mmol/L] were significantly higher as compared with MTHFR 677CC genotype [0.90 (0.60–1.15) mmol/L, P = 0.007], and the MTRR 66GG genotype carriers had higher serum high-density lipoprotein cholesterol levels than those with MTRR 66AG genotype (1.46 ± 0.50 vs. 1.19 ± 0.31 mmol/L, P = 0.058). Furthermore, in male subjects with overweight/obesity, the MTHFR 677CT genotype carriers had higher low-density lipoprotein cholesterol levels than those with MTHFR 677TT genotype (2.96 ± 1.07 vs. 2.74 ± 0.88 mmol/L, P = 0.015).

Conclusions

Our results indicate that there exist interactive effects of the MTHFR C677T and MTRR A66G polymorphisms with overweight/obesity on some lipid traits in Chinese Han population, and the effects were gender-specific.

Interactions of Methylenetetrahydrofolate Reductase C677T Polymorphism with Environmental Factors on Hypertension Susceptibility

Hypertension is considered to be the result of genes, environment, and their interactions. Among them age, sex, tobacco use, alcohol consumption, and being overweight/obesity are well documented environmental determinants, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is nominated as a potential genetic candidate. However, the synergistic effect of the MTHFR C677T polymorphism with these environmental factors on the risk of hypertension has received little attention. The aim of this study was to explore the associations of the MTHFR C677T polymorphism, environmental factors, and their interactions with hypertension predisposition in a Northern Chinese Han population. A total of 708 participants were enrolled in the study. The genotypes of the MTHFR C677T were determined by a TaqMan assay. We found that participants of an older age, being overweight/obesity, with a smoking habit, drinking habit, or carrying the 677T allele were at an increased risk of hypertension. Additionally, there existed marginally significant interactions of the polymorphism with age and overweight/obesity. However, future large, well-designed studies in Chinese and other populations, as well as mechanistic studies, are still needed to validate our findings, especially considering that the interactions observed in our study were only marginally significant.

Functional and Structural Impact of ATP-Binding Cassette Transporter A1 R219K and I883M Gene Polymorphisms in Obese Children and Adolescents

INTRODUCTION

Obesity is a serious medical condition that affects children and adolescents. ATP-binding cassette transporter A1 (ABCA1) protein is known to mediate the transport of intracellular cholesterol and phospholipids across the cell membranes. Thus, we aimed to investigate the association between ABCA1 gene polymorphisms and overweight/obesity risk, and to evaluate their relation to the lipid profile.

MATERIALS AND METHODS

The study included in silico analysis of ABCA1 gene and protein. Two genetic variants in ABCA1 gene-R219K (rs2230806; G/A) and I883M (rs2066714; A/G)-were genotyped in 128 normal weight and 128 overweight/obese subjects using polymerase chain reaction-restriction fragment length polymorphism technology. Anthropometric and biochemical assessments were performed.

RESULTS

Our findings suggest that the heterozygote GA genotype of R219K polymorphism increased susceptibility to obesity under the heterozygous model (odds ratio 2.75, 95 % CI 1.01-6.12; p = 0.014) compared with the control group. This susceptibility could be gender-specific, with higher risk among females. In addition, the A variant was associated with a higher degree of obesity (p < 0.001). On the other hand, individuals with the G variant of I883M polymorphism showed lower susceptibility to obesity under all genetic models (allelic, homozygote, heterozygote, dominant, and recessive models; p < 0.05), with no observed association with body mass index or degree of obesity. However, both single nucleotide polymorphisms (SNPs) showed significant differences in lipid levels among patients with different genotypes.

CONCLUSIONS

The study results suggest that R219K and I883M SNPs of the ABCA1 gene may play a role in susceptibility to obesity in our Egyptian population; the former increases susceptibility and phenotype severity, and the latter is protective. Larger epidemiological studies are needed for validation of the results.

Association between Polymorphisms and Haplotype in the ABCA1 Gene and Overweight/Obesity Patients in the Uyghur Population of China

OBJECTIVE

This study aimed to detect the association between polymorphisms and haplotype in the ATP-binding cassette transporter A1 (ABCA1) gene and overweight/obese Uyghur patients in China.

METHODS

A total of 259 overweight/obese patients and 276 normal weight subjects, which were randomly selected from among 3049 adult Uyghurs, were matched for age. We genotyped ABCA1 single nucleotide polymorphisms of rs2515602, rs3890182, rs2275542, rs2230806, rs1800976, and rs4149313.

RESULTS

(1) The genotypic and allelic frequencies of rs2515602 and rs4149313 differed between the control group and case group. The genotypic frequency of rs2275542 also differed between the control group and case group (p < 0.05); (2) rs2515602, rs2230806, and rs4149313 polymorphisms were significantly related to risk of overweight/obese; (3) a significant linkage disequilibrium (LD) was observed between the ABCA1 gene rs2275542 with rs3890182 and rs2515602 with rs4149313. (4) the C-C-C-A-G-G, T-C-G-A-G-G, and T-T-G-G-G-A haplotypes were significant in normal weight and overweight/obese subjects (p < 0.05); (5) the levels of HDL-C (rs2515602, rs2275542, rs4149313) in normal weight subjects were different among the genotypes (p < 0.05); the levels of TC, LDL-C and TG (rs1800976) in overweight/obese subjects were different among the genotypes (p < 0.05).

CONCLUSIONS

The rs2515602, rs4149313, and rs2275542 polymorphisms were associated with overweight/obese conditions among Uyghurs. Strong LD was noted between rs2275542 with rs3890182 and rs2515602 with rs4149313. The C-C-C-A-G-G and T-C-G-A-G-G haplotypes may serve as risk factors of overweight/obesity among Uyghurs. The T-T-G-G-G-A haplotype may serve as a protective factor of overweight/obesity among Uyghurs. Rs2515602, rs2275542, rs4149313, and rs1800976 polymorphisms in the ABCA1 gene may influence lipid profiles.

Association between the DOCK7, PCSK9 and GALNT2 Gene Polymorphisms and Serum Lipid levels

This study was to determine the association between several single nucleotide polymorphisms (SNPs) in the dedicator of cytokinesis 7 (DOCK7), proprotein convertase subtilisin/kexin type 9 (PCSK9) and polypeptide N-acetylgalactosaminyltransferase 2 (GALNT2) and serum lipid levels. Genotyping of 9 SNPs was performed in 881 Jing subjects and 988 Han participants. Allele and genotype frequencies of the detected SNPs were different between the two populations. Several SNPs were associated with triglyceride (TG, rs10889332, rs615563, rs7552841, rs1997947, rs2760537, rs4846913 and rs11122316), high-density lipoprotein (HDL) cholesterol (rs1997947), low-density lipoprotein (LDL) cholesterol (rs1168013 and rs7552841), apolipoprotein (Apo) A1 (rs1997947), ApoB (rs10889332 and rs7552841), and ApoA1/ApoB ratio (rs7552841) in Jing minority; and with TG (rs10889332, rs615563, rs7552841, rs11206517, rs1997947, rs4846913 and rs11122316), HDL cholesterol (rs11206517 and rs4846913), LDL cholesterol (rs1168013), ApoA1 (rs11206517 and rs4846913), ApoB (rs7552841), and ApoA1/ApoB ratio (rs4846913) in Han nationality. Strong linkage disequilibria were noted among the SNPs. The commonest haplotype was G-C-G-C-T-G-C-C-G (>10%). The frequencies of C-C-G-C-T-G-T-C-G, G-C-A-C-T-G-C-C-G, G-C-G-C-T-A-C-C-A, G-C-G-C-T-G-C-C-A, G-C-G-C-T-G-T-C-A haplotypes were different between the two populations. Haplotypes could explain much more serum lipid variation than any single SNP alone especially for TG. Differences in lipid profiles between the two populations might partially attribute to these SNPs and their haplotypes.

Serum lipid profiles, the prevalence of dyslipidemia and the risk factors in two isolated Chinese minorities

Both Jing and Mulao nationalities are the isolated minorities in China. Little is known about the prevalence of dyslipidemia between the two ethnic groups. Therefore, the aim of this study was to compare the differences in serum lipid profiles, the prevalence of dyslipidemia and their risk factors between the Jing and Mulao populations. A cross-sectional study of dyslipidemia was conducted in Dongxing city, Guangxi, China, during Dec 2011 and Jan 2012. A total of 1254 subjects of Jing and 1251 participants of Mulao were surveyed by a stratified randomized sampling. Information on demography, diet and lifestyle was collected with standardized questionnaire. Serum lipid levels were detected using the commercially available kits. The levels of low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) A1, and the ratio of ApoA1 to ApoB were lower but the levels of ApoB were higher in Jing than in Mulao (P < 0.001 for all). The prevalence of hypertriglyceridemia (32.38% vs. 24.38%), high ApoB (35.25% vs. 15.35%) and low ApoA1/ApoB ratio (22.65% vs. 16.87%) was higher and low high-density lipoprotein cholesterol (0.48% vs. 2.16%), high LDL-C (17.54% vs. 40.53%) and low ApoA1 (5.98% vs. 11.43%) was lower in Jing than in Mulao (P < 0.001 for all). The risk factors for serum lipid parameters and hyperlipidemia were different between the two ethnic groups. Serum lipid profiles, the prevalence of dyslipidemia and their risk factors are different between the Jing and Mulao populations. These differences may result from the combined effects of different diet, lifestyle, and genetic factors.

Association of the SPT2 chromatin protein domain containing 1 gene rs17579600 polymorphism and serum lipid traits

SPT2 chromatin protein domain containing 1 gene (SPTY2D1) is a candidate gene for dyslipidemia. The single nucleotide polymorphism (SNP) of rs7934205 near SPTY2D1 locus was ethnic- and sex-specific associated with serum lipid levels in our previous study. Whether SPTY2D1 rs17579600 SNP and several environmental factors are associated with serum lipid profiles is unknown. A total of 712 participants of Han and 689 unrelated individuals of Mulao were included. The genotype and allele frequencies of SPTY2D1 rs17579600 SNP were different between the Han and Mulao populations (TT, 74.3% vs. 55.7%; TC, 17.6% vs. 31.2%, CC, 8.1% vs. 13.1%, P = 0.028; T, 83.1% vs. 71.3%; C, 16.9% vs. 28.7%, P = 0.044), and between males and females in the both ethnic groups. The levels of serum apolipoprotein (Apo) A1 in Han, triglyceride (TG) in Mulao, and total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), ApoA1 and ApoB in Mulao males were difference among the genotypes. The C allele carriers had higher ApoA1 in Han, lower TG in Mulao, and lower TC, LDL-C and ApoB and higher ApoA1 in Mulao males than the C allele non-carriers. Serum lipid parameters were also associated with several environmental factors in both ethnic groups. The differences suggesting there may be a racial/ethnic- and/or sex-specific association between the SPTY2D1 rs17579600 SNP and serum lipid parameters in some ethnic groups.

Interactions of several genetic polymorphisms and alcohol consumption on blood pressure levels

This study aimed to detect the interactions of several single nucleotide polymorphisms (SNPs) and alcohol consumption on blood pressure levels. Genotypes of 10 SNPs in the ATP-binding cassette transporter A1 (ABCA-1), acyl-CoA:cholesterol acyltransferase-1 (ACAT-1), low density lipoprotein receptor (LDLR), hepatic lipase gene (LIPC), endothelial lipase gene (LIPG), methylenetetrahydrofolate reductase (MTHFR), the E3 ubiquitin ligase myosin regulatory light chain-interacting protein (MYLIP), proprotein convertase subtilisin-like kexin type 9 (PCSK9), peroxisome proliferator-activated receptor delta (PPARD), and Scavenger receptor class B type 1 (SCARB1) genes were determined in 616 nondrinkers and 608 drinkers. The genotypic frequencies of LDLR rs5925, LIPC rs2070895, MTHFR rs1801133, and MYLIP rs3757354 SNPs were significantly different between nondrinkers and drinkers. The levels of systolic blood pressure (ABCA-1 rs2066715 and rs2070895), diastolic blood pressure (rs2070895), and pulse pressure (PP) (rs2066715, ACAT-1 rs1044925, and rs1801133) in nondrinkers, and systolic blood pressure (rs1044925 and SCARB1 rs5888), diastolic blood pressure (rs1044925 and LIPG rs2000813), and PP (PCSK9 rs505151 and rs5888) in drinkers were different among the genotypes (P < 0.005-0.001). The interactions of several SNPs and alcohol consumption on systolic blood pressure (rs2066715, rs1044925, rs5925, rs2070895, rs1801133, rs3757354, PPARD rs2016520, and rs5888), diastolic blood pressure (rs2066715, rs1044925, rs5925, rs2000813, rs3757354, and rs2016520), and PP (rs1044925, rs2070895, rs1801133, rs3757354, rs505151, and rs5888) were observed (P < 0.005-0.001). The differences in blood pressure levels between the nondrinkers and drinkers might be partially attributed to the interactions of these SNPs and alcohol consumption.

The MYLIP p.N342S polymorphism is associated with response to lipid-lowering therapy in Brazilian patients with familial hypercholesterolemia

Supplemental Digital Content is available in the text.

Background

A previous study reported that the myosin regulatory light chain interacting protein (MYLIP) might serve as a novel therapeutic class for treating dyslipidemia. It contributes to variations in the levels of circulating low-density lipoprotein cholesterol (LDL-C), promoting the degradation of LDL–LDLR, thus limiting absorption. The effect of genetic variation in the MYLIP gene in a disease scenario characterized by mutations in the LDLR gene has not been previously evaluated.

Objective

The aim of this study was to assess the effect of the p.N342S variant on the response to lipid-lowering therapy in Brazilian patients with heterozygous familial hypercholesterolemia (FH).

Patients and methods

A total of 156 patients with heterozygous FH were followed up for 12 months and received lipid-lowering therapy (different doses of atorvastatin with the addition of ezetimibe in over half the patients of each genotype group). Cholesterol data were assessed, and analysis of the MYLIP rs9370867 (p.N342S) genotypes was carried out by melting curve analysis.

Results

Baseline total cholesterol and baseline LDL-C levels were not different between genotypes. After 1 year of treatment, LDL-C responses (expressed as mg/dl and as %) were significantly different among genotypes (AA: −79±68 and −39±27, GA: −60±79 and −27±32, and GG: −30±83 and −15±38; P=0.02 and 0.005, respectively). In addition, FH patients carrying the AA genotype were more likely to achieve LDL-C levels of less than 130 mg/dl after 1 year of treatment (75.0%) compared with patients with the GG and GA genotypes (34.5 and 34.8%, respectively; P=0.001).

Conclusion

Our study indicates that MYLIP p.N342S might be a pharmacogenetic marker for lipid-lowering therapy in patients with FH.

Suppressor of cytokine signaling 3 A+930-->G (rs4969168) polymorphism is associated with apolipoprotein A1 and low-density lipoprotein cholesterol

This study aimed to detect the association of the suppressor of cytokine signaling 3 gene (SOCS3) A+930-->G (rs4969168) single nucleotide polymorphism (SNP) and environmental factors with serum lipid levels in the Han and Mulao populations. Genotyping of the SOCS3 A+930-->G (rs4969168) SNP was performed in 752 of Han and 690 of Mulao participants using polymerase chain reaction and restriction fragment length polymorphism. The genotype and allele frequencies were significantly different between the Han and Mulao populations (GG, 57.71% vs. 51.16%, GA, 36.97% vs. 41.16%, AA, 5.32% vs. 7.68%, P = 0.023; G, 76.20% vs. 71.74%, A, 23.80% vs. 28.26%; P = 0.006; respectively). Serum apolipoprotein (Apo) A1 levels in Han were different among the genotypes (P < 0.05). Subgroup analyses showed that the levels of ApoA1 in Han females, and ApoA1 and low-density lipoprotein cholesterol (LDL-C) in Mulao males were different among the genotypes (P < 0.05). Serum lipid parameters were also associated with several environmental factors in both ethnic groups (P < 0.05-0.001). These findings suggest that there may be a racial/ethnic- and/or sex-specific association between the SOCS3 A+930-->G (rs4969168) SNP and serum lipid parameters in some populations.

Are MTHFR C677T and MTRR A66G Polymorphisms Associated with Overweight/Obesity Risk? From a Case-Control to a Meta-Analysis of 30,327 Subjects

Several studies have examined the associations of methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms with being overweight/obesity. However, the results are still controversial. We therefore conducted a case-control study (517 cases and 741 controls) in a Chinese Han population and then performed a meta-analysis by combining previous studies (5431 cases and 24,896 controls). In our case-control study, the MTHFR C677T polymorphism was not significantly associated with being overweight/obesity when examining homozygous codominant, heterozygous codominant, dominant, recessive and allelic genetic models. The following meta-analysis confirmed our case-control results. Heterogeneity was minimal in the overall analysis, and sensitivity analyses and publication bias tests indicated that the meta-analytic results were reliable. Similarly, both the case-control study and meta-analysis found no significant association between the MTRR A66G polymorphism and being overweight/obesity. However, sensitivity analyses showed that the associations between the MTRR A66G polymorphism and being overweight/obesity became significant in the dominant, heterozygous codominant and allelic models after excluding our case-control study. The results from our case-control study and meta-analysis suggest that both of the two polymorphisms are not associated with being overweight/obesity. Further large-scale population-based studies, especially for the MTRR A66G polymorphism, are still needed to confirm or refute our findings.

MTHFR C677T polymorphism affects normotensive diastolic blood pressure independently of blood lipids

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism was found to be associated with hypertension. High blood pressure (BP) is a major risk factor for cardiovascular disease, gestational hypertension, and high-risk pregnancy. BP is a complex trait strongly associated with blood lipid parameters. However, studies of the effect of MTHFR C677T polymorphism on BP levels independently of blood lipids are scarce. Our objective was to analyze and quantify the effect of MTHFR C677T polymorphism on normotensive BP independently of blood lipids.

METHODS

MTHFR C677T genotyping was done for 151 Israeli women attending the genetics clinic at Soroka Medical Center. Biochemical (blood lipids) and BP data were extracted from Soroka Medical Center records. BP was regarded as a continuous parameter using analysis of covariance and post hoc Tukey's HSD (honestly significant difference) analysis.

RESULTS

The frequencies of genotypes CC, TT, and CT were 41%, 12%, and 47%, respectively. A significant (P < 0.0001) association was found between genotype and diastolic BP (DBP) when adjusted to body mass index and age. Mean DBP was significantly lower for CC than for TT genotypes (71.2 vs. 78.7 mm Hg); however the difference between the heterozygotes (73.9 mm Hg) and the other 2 genotypes was not significant. Cholesterol, LDLcalc (LDLcalculaed), and homocysteine blood levels significantly contributed to the effect of MTHFR C677T polymorphism on the DBP trait. There was also significant association between genotype and folic acid levels.

CONCLUSIONS

MTHFR C677T polymorphism significantly affects DBP in Israeli women, independently of blood lipids. Each C to T substitution is associated with a mean 3.4-mm Hg increase in DBP.

Sex-specific association of the SPTY2D1 rs7934205 polymorphism and serum lipid levels

The objective of the present study was to detect the association of the rs7934205 single nucleotide polymorphism (SNP) near the Suppressor of Ty, domain containing 1 gene (SPTY2D1) and serum lipid levels between males and females in the Mulao and Han populations. Genotyping of SPTY2D1 rs7934205 SNP was performed in 933 of Mulao and 865 of Han participants using polymerase chain reaction and restriction fragment length polymorphism. The T allele frequency was different between Mulao males and females (23.2% vs. 27.9%, P = 0.018). The genotype and allele frequencies were also different between Han males and females (P = 0.020 and P = 0.004; respectively). Serum levels of apolipoprotein (Apo) A1 in Mulao males; and total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), ApoA1 and ApoB in Mulao females were different between the CC and CT/TT genotypes (P < 0.05). Serum TC, ApoB levels in Han males, and ApoB levels in Han females were different between the CC and CT/TT genotypes (P < 0.05). The subjects with CT/TT genotype in both Mulao and Han males and females have more favorable lipid profiles than those with CC genotype. These findings suggest that the association between the SPTY2D1 rs7934205 SNP and serum lipid levels might have ethnic- and/or sex-specificity.

Effect of E670G Polymorphism in PCSK9 Gene on the Risk and Severity of Coronary Heart Disease and Ischemic Stroke in a Tunisian Cohort

The association of E670G (rs505151) polymorphism in PCSK9 gene with an increased risk of coronary artery disease (CAD) and ischemic stroke (IS) was reported in previous studies. We investigated the effect of the E670G (rs505151) on the risk of CAD and IS in a Tunisian cohort. Genotyping of the PCSK9 E670G was performed using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) and then confirmed by direct sequencing. The frequency of the 670G allele was significantly higher in the CAD than in the no-CAD subgroup (0.132 vs. 0.068, p = 0.030). As expected, the incidence of E670G was significantly important in IS subgroup than control group (0.122 vs. 0.073, p = 0.032). Furthermore in CAD patients, the 670G carriers showed significantly increased plasma total cholesterol and LDL-cholesterol levels compared to E670 carriers (6.78 [6.47-7.00] vs. 4.92 [4.02-5.46] mmol/l, p < 0.0001 and 4.60 [4.00-5.04] vs. 3.00 [2.22-3.70] mmol/l p = 0.001, respectively). The risk and severity of CAD were significantly increased in 670G carriers between no-CAD subgroup and CAD patients presenting a stenosis ≥50 % in two or three major coronary arteries (0.068 vs. 0.198, p = 0.001, OR = 3.39 [1.55-7.37]). The E670G polymorphism of the PCSK9 gene is mainly associated with a increased risk and severity of CAD and IS in Tunisian cohort.

Sex-specific association of the zinc finger protein 259 rs2075290 polymorphism and serum lipid levels

BACKGROUND

Little is known about the association of ZNF259 rs2075290 single nucleotide polymorphism (SNP) and serum lipid levels in the Chinese population. This study aimed to detect the association of ZNF259 rs2075290 SNP and environmental factors with serum lipid levels between males and females in the Mulao and Han populations.

METHODS AND RESULTS

Genotyping of ZNF259 rs2075290 SNP was performed in 788 of Mulao and 778 of Han participants using polymerase chain reaction and restriction fragment length polymorphism. The genotype frequencies were significantly different between Mulao and Han populations (AA, 50.1% Vs 58.9%; AG, 42.3% Vs 35.7%; GG, 7.6% Vs 5.4%, P = 0.002) and between Han males and females (AA, 64.5% Vs 55.2%; AG, 28.3% Vs 40.6%; GG, 7.2% Vs 4.2%, P = 0.001). Serum levels of triglyceride (TG) in Mulao males, and total cholesterol (TC), TG and low-density lipoprotein cholesterol (LDL-C) in Mulao females were different between the AA and AG/GG genotypes (P < 0.05-0.001). Serum TC, LDL-C and apolipoprotein (Apo) A1 levels in Han males, and TG and ApoB levels and ApoA1/ApoB ratio in Han females were different between the AA and AG/GG genotypes (P < 0.05-0.001). An interaction between ZNF259 rs2075290 polymorphism and male gender on serum TC, LDL-C, and ApoA1 levels was noted in Han population (P < 0.05-0.01) but not in Mulao's.

CONCLUSIONS

The subjects with AG/GG genotype in Mulao males and females and Han females have less favorable lipid profiles than those with AA genotype. In contrast, the subjects with AG/GG genotype in Han males have more favorable lipid profiles than those with AA genotype. These findings suggest that the association between ZNF259 rs2075290 SNP and serum lipid levels might have ethnic- and/or sex-specificity.

Association of the MLXIPL/TBL2 rs17145738 SNP and serum lipid levels in the Guangxi Mulao and Han populations

Background

The rs17145738 single nucleotide polymorphism (SNP) near MLX interacting protein-like/transducin (beta)-like 2 (MLXIPL/TBL2) loci is associated with serum lipid levels, but the results are inconsistent in diverse ethnic/racial groups. The current study was to investigate the association of MLXIPL/TBL2 rs17145738 SNP and several environmental factors with serum lipid profiles in the Guangxi Mulao and Han populations.

Methods

A total of 649 subjects of Mulao nationality and 712 participants of Han nationality aged 16–84 years were randomly selected from our previous stratified randomized samples. Genotyping was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

Results

Serum apolipoprotein (Apo) B levels were higher in Mulao than in Han (P < 0.001). There were no significant differences in the genotypic and allelic frequencies of the MLXIPL/TBL2 rs17145738 SNP between the two ethnic groups or between males and females. The T allele carriers had higher triglyceride (TG) and ApoB levels in Mulao, and higher total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels in Han than the T allele non-carriers (P < 0.05 for all). Subgroup analyses showed that the T allele carriers had higher ApoB levels in both Mulao and Han females than the T allele non-carriers, but the T allele carriers had lower ApoB levels in Han males than the T allele non-carriers (P < 0.05, respectively). The T allele carriers in Han had higher TC, high-density lipoprotein cholesterol (HDL-C) levels and ApoA1/ApoB ratio and lower TG levels in males, and higher LDL-C levels and lower ApoA1/ApoB ratio in females than the T allele non-carriers (P < 0.05 for all). Serum TC levels in the combined population of the two ethnic groups and in Han, and HDL-C levels in Han males were correlated with genotypes (P < 0.05 for all). Serum lipid parameters were also correlated with several environmental factors (P < 0.05-0.01).

Conclusions

The association of MLXIPL/TBL2 rs17145738 SNP and serum lipid profiles is different between the Mulao and Han populations. There is a sex-specific association in the both ethnic groups.

Genetic variants predicting left ventricular hypertrophy in a diabetic population: a Go-DARTS study including meta-analysis

Background

Left ventricular hypertrophy has multiple aetiologies including diabetes and genetic factors. We aimed to identify genetic variants predicting left ventricular hypertrophy in diabetic individuals.

Methods

Demographic, echocardiographic, prescribing, morbidity, mortality and genotyping databases connected with the Genetics of Diabetes Audit and Research in Tayside, Scotland project were accurately linked using a patient-specific identifier. Left ventricular hypertrophy cases were identified using echocardiographic data.

Genotyping data from 973 cases and 1443 non-left ventricular hypertrophy controls were analysed, investigating whether single nucleotide polymorphisms associated with left ventricular hypertrophy in previous Genome Wide Association Studies predicted left ventricular hypertrophy in our population of individuals with type 2 diabetes. Meta-analysis assessed overall significance of these single nucleotide polymorphisms, which were also used to create gene scores. Logistic regression assessed whether these scores predicted left ventricular hypertrophy.

Results

Two single nucleotide polymorphisms previously associated with left ventricular hypertrophy were significant: rs17132261: OR 2.03, 95% CI 1.10-3.73, p-value 0.02 and rs2292462: OR 0.82, 95% CI 0.73-0.93 and p-value 2.26x10^-3. Meta-analysis confirmed rs17132261 and rs2292462 were associated with left ventricular hypertrophy (p=1.03x10^-8 and p=5.86x10^-10 respectively) and one single nucleotide polymorphisms in IGF1R (rs4966014) became genome wide significant upon meta-analysis although was not significant in our study. Gene scoring based on published single nucleotide polymorphisms also predicted left ventricular hypertrophy in our study.

Rs17132261, within SLC25A46, encodes a mitochondrial phosphate transporter, implying abnormal myocardial energetics contribute to left ventricular hypertrophy development. Rs2292462 lies within the obesity-implicated neuromedin B gene. Rs4966014 lies within the IGF1R1 gene. IGF1 signalling is an established factor in cardiac hypertrophy.

Conclusions

We created a resource to study genetics of left ventricular hypertrophy in diabetes and validated our left ventricular hypertrophy phenotype in replicating single nucleotide polymorphisms identified by previous genome wide association studies investigating left ventricular hypertrophy.

Inverse associations between light-to-moderate alcohol intake and lipid-related indices in patients with diabetes

Background

Dyslipidemia is a common complication in patients with diabetes and is involved in being prone to cardiovascular disease. The risk of coronary artery disease is known to be lower in light-to-moderate drinkers than in abstainers. The aim of this study was to clarify whether and how alcohol drinking influences the lipid-related indices, good predictors for cardiovascular disease, such as the ratio of LDL cholesterol to HDL cholesterol (LDL-C/HDL-C ratio), the ratio of triglycerides to HDL cholesterol (TG/HDL-C ratio), and the lipid accumulation product (LAP), in patients with diabetes.

Methods

The subjects were men with diabetes (n = 1477; mean age, 54.0 years) and they were divided into non-, light (< 22 g ethanol/day), moderate (≥ 22 and < 44 g ethanol/day) and heavy (≥ 44 g ethanol/day) drinkers. The relationships between alcohol intake and the lipid-related indices were investigated by the multivariate analyses with adjustment for age, smoking, regular exercise and drug therapy for diabetes.

Results

The odds ratio (OR) vs. nondrinkers for high LDL-C/HDL-C ratio tended to be lower with an increase in alcohol intake (OR with 95% confidence interval (CI): 0.80 [0.50-1.29] in light drinkers; 0.24 [0.15-0.38] in moderate drinkers and 0.10 [0.05-0.19] in heavy drinkers). Alcohol intake showed an inverse association with a high TG/HDL-C ratio (OR with 95% CI vs. nondrinkers for high TG/HDL-C ratio: 0.54 [0.36-0.80] in light drinkers; 0.73 [0.56-0.97] in moderate drinkers and 0.72 [0.53-0.98] in heavy drinkers) and a J-shaped relationship with a high LAP (OR with 95% CI vs. nondrinkers for high LAP: 0.66 [0.43-1.02] in light drinkers; 0.82 [0.61-1.10] in moderate drinkers, and 1.29 [0.95-1.77] in heavy drinkers). Similar associations between alcohol intake and the lipid indices were obtained in a covariance analysis.

Conclusions

In patients with diabetes, light-to-moderate alcohol consumption is inversely associated with lipid-related indices, and this correlates with previous findings of cardiovascular risk reduction by modest drinking in patients with diabetes.

Impact of HDL genetic risk scores on coronary artery calcified plaque and mortality in individuals with type 2 diabetes from the Diabetes Heart Study

Background

Patients with type 2 diabetes (T2D) are at elevated risk for cardiovascular disease (CVD) events and mortality. Recent studies have assessed the impact of genetic variants affecting high-density lipoprotein cholesterol (HDL) concentrations on CVD risk in the general population. This study examined the utility of HDL-associated single nucleotide polymorphisms (SNPs) for CVD risk prediction in European Americans with T2D enrolled in the Diabetes Heart Study (DHS).

Methods

Genetic risk scores (GRS) of HDL-associated SNPs were constructed and evaluated for potential associations with mortality and with coronary artery calcified atherosclerotic plaque (CAC), a measure of subclinical CVD strongly associated with CVD events and mortality. Two sets of SNPs were used to construct GRS; while all SNPs were selected primarily for their impacts on HDL, one set of SNPs had pleiotropic effects on other lipid parameters, while the other set lacked effects on low-density lipoprotein cholesterol (LDL) or triglyceride concentrations.

Results

The GRS were specifically associated with HDL concentrations (4.90 × 10^-7 < p < 0.02) in models adjusted for age, sex, and body mass index (BMI), but were not associated with LDL or triglycerides. Cox proportional hazards regression analysis suggested the HDL-associated GRS had no impact on risk of CVD-mortality (0.48 < p < 0.99) in models adjusted for other known CVD risk factors. However, associations between several of the GRS and CAC were observed (3.85 × 10^-4 < p < 0.03) in models adjusted for other known CVD risk factors.

Conclusions

The GRS analyzed in this study provide a tool for assessment of HDL-associated SNPs and their impact on CVD risk in T2D. The observed associations between several of the GRS and CAC suggest a potential role for HDL-associated SNPs on subclinical CVD risk in patients with T2D.

Polymorphisms of PTPN11 gene could influence serum lipid levels in a sex-specific pattern

Background

Previous studies have reported that different genotypes of PTPN11 gene (protein tyrosine phosphatase, non-receptor 11) were associated with different levels of serum lipids. The aim of this study was to explore the relationship between single nucleotide polymorphisms (SNPs) of PTPN11 and serum lipids in Northeast Chinese.

Methods

A total of 1003 subjects, 584 males and 419 females, were included in the study and their serum lipids were determined. Five htSNPs (rs2301756, rs12423190, rs12229892, rs7958372 and rs4767860) of PTPN11 gene were genotyped using TaqMan assay method.

Results

All of the five SNPs were in Hardy-Weinberg equilibrium. The male subjects had higher triglyceride (TG), higher low-density lipoprotein cholesterol (LDL-C) and lower high-density lipoprotein cholesterol (HDL-C) level than females. In males, rs4767860 was found to be associated with serum TG and total cholesterol (TC) levels and rs12229892 was associated with TC level. However, these significant associations could not be observed in females. In females, rs2301756 was found to be associated with TG and rs7958372 was associated with LDL-C level. Haplotype analysis showed that the GCGTG haplotype was associated with slightly higher TG level and ATGCG with higher TC level.

Conclusions

SNPs of PTPN11 may play a role in serum lipids in a sex-specific pattern. However, more studies are needed to confirm the conclusion and explore the underlying mechanism.

Dyslipidemia in obesity: mechanisms and potential targets

Obesity has become a major worldwide health problem. In every single country in the world, the incidence of obesity is rising continuously and therefore, the associated morbidity, mortality and both medical and economical costs are expected to increase as well. The majority of these complications are related to co-morbid conditions that include coronary artery disease, hypertension, type 2 diabetes mellitus, respiratory disorders and dyslipidemia. Obesity increases cardiovascular risk through risk factors such as increased fasting plasma triglycerides, high LDL cholesterol, low HDL cholesterol, elevated blood glucose and insulin levels and high blood pressure. Novel lipid dependent, metabolic risk factors associated to obesity are the presence of the small dense LDL phenotype, postprandial hyperlipidemia with accumulation of atherogenic remnants and hepatic overproduction of apoB containing lipoproteins. All these lipid abnormalities are typical features of the metabolic syndrome and may be associated to a pro-inflammatory gradient which in part may originate in the adipose tissue itself and directly affect the endothelium. An important link between obesity, the metabolic syndrome and dyslipidemia, seems to be the development of insulin resistance in peripheral tissues leading to an enhanced hepatic flux of fatty acids from dietary sources, intravascular lipolysis and from adipose tissue resistant to the antilipolytic effects of insulin. The current review will focus on these aspects of lipid metabolism in obesity and potential interventions to treat the obesity related dyslipidemia.

Association of the rs7395662 SNP in the MADD-FOLH1 and several environmental factors with serum lipid levels in the Mulao and Han populations

BACKGROUND

The rs7395662 single nucleotide polymorphism (SNP) in the MADD-FOLH1 has been associated with serum lipid traits, but the results are inconsistent in different populations. The present study was undertaken to investigate the association of rs7395662 SNP and several environmental factors with serum lipid levels in the Guangxi Mulao and Han populations.

METHOD

A total of 721 subjects of Mulao and 727 subjects of Han Chinese were randomly selected from our previous stratified randomized samples. Genotyping of the SNP was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and confirmed by direct sequencing.

RESULTS

Serum apolipoprotein (Apo) B levels were higher in Mulao than in Han (P < 0.01). The allelic and genotypic frequencies in Han were different between males and females (P < 0.05 for each), but there was no difference between Mulao and Han or between Mulao males and females. The levels of low-density lipoprotein cholesterol (LDL-C) and ApoB in Mulao females were different among the genotypes (P < 0.05), the G allele carriers had higher LDL-C and ApoB levels than the G allele non-carriers. The levels of total cholesterol (TC), triglyceride (TG), LDL-C and ApoB in Han males and TC, TG and high-density lipoprotein cholesterol (HDL-C) in Han females were different among the genotypes (P < 0.05-0.01), the subjects with GG genotype in Han males had higher TC, TG, and ApoB and lower LDL-C levels than the subjects with AA or AG genotype, and the G allele carriers in Han females had lower TC and HDL-C levels than the G allele non-carriers. The levels of LDL-C and ApoB in Mulao females were correlated with the genotypes (P < 0.05 for each). The levels of HDL-C and ApoAI in Han males and HDL-C in Han females were correlated with genotypes (P < 0.05-0.001). Serum lipid parameters were also correlated with several environmental factors in both ethnic groups (P < 0.05-0.01).

CONCLUSION

The association of rs7395662 SNP and serum lipid levels is different between the Mulao and Han populations, and between males and females in both ethnic groups.