TaqIB polymorphism in the CETP gene modulates the impact of HC/LF diet on the HDL profile in healthy Chinese young adults

Dietary acid load and its interaction with CETP TaqB1 polymorphisms on lipid profile among patients with Type 2 diabetes mellitus

OBJECTIVE

Gene-diet interaction plays a key role in the inter-individual differences in lipid abnormalities as a major risk factor for cardiovascular diseases (CVDs). Thus, we explored the interaction between CETP TaqB1 polymorphism with dietary acid load (DAL) on lipid profile among type 2 diabetes mellitus (T2DM).

METHOD

This cross-sectional study conducted on 220 Iranian patients with T2DM. Dietary acid load (PRAL and NEAP) was calculated via a validated food-frequency questionnaire (FFQ). The polymerase chain reaction (PCR) used for genotyping Taq1B polymorphism. Biochemical markers were measured by standard protocol. The interaction between CETP Taq1B polymorphism and DAL (PRAL and NEAP) on lipid profile was performed by a generalized linear regression model (GLM).

RESULTS

The overall prevalence of rs708272 genotypes was 8.6%, 72.7% and 18.6% for B1B1, B1B2 and B2B2 genotype respectively. This study showed that people with the B1B1 genotype had greater LDL, TC, LDL/HDL, and TG when they consumed diets that scored higher on the NEAP and PRAL indexes than those with the B1B2 and B2B2 genotypes. Besides, carriers of the B1B1 allele who were in the highest tertile of NEAP, had lower HDL (P Interaction < 0.05).

CONCLUSIONS

In summary, the lipid profile might be improved in B1B1 homozygotes by less adherence to DAL indexes, however, the findings should be validated in high-quality interventional studies.

A Nutrigenetic Update on CETP Gene–Diet Interactions on Lipid-Related Outcomes

Purpose of Review

An abnormal lipid profile is considered a main risk factor for cardiovascular diseases and evidence suggests that single nucleotide polymorphisms (SNPs) in the cholesteryl ester transfer protein (CETP) gene contribute to variations in lipid levels in response to dietary intake. The objective of this review was to identify and discuss nutrigenetic studies assessing the interactions between CETP SNPs and dietary factors on blood lipids.

Recent Findings

Relevant articles were obtained through a literature search of PubMed and Google Scholar through to July 2021. An article was included if it examined an interaction between CETP SNPs and dietary factors on blood lipids. From 49 eligible nutrigenetic studies, 27 studies reported significant interactions between 8 CETP SNPs and 17 dietary factors on blood lipids in 18 ethnicities. The discrepancies in the study findings could be attributed to genetic heterogeneity, and differences in sample size, study design, lifestyle and measurement of dietary intake. The most extensively studied ethnicities were those of Caucasian populations and majority of the studies reported an interaction with dietary fat intake. The rs708272 (TaqIB) was the most widely studied CETP SNP, where ‘B1’ allele was associated with higher CETP activity, resulting in lower high-density lipoprotein cholesterol and higher serum triglycerides under the influence of high dietary fat intake.

Summary

Overall, the findings suggest that CETP SNPs might alter blood lipid profiles by modifying responses to diet, but further large studies in multiple ethnic groups are warranted to identify individuals at risk of adverse lipid response to diet.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11883-022-00987-y.

Interaction between CETP polymorphism and dietary insulin index and load in relation to cardiovascular risk factors in diabetic adults

Gene-diet interactions may play an important role in the inter individual diversity observed in on cardiovascular disease (CVD) risk factors. Therefore, in the current study, we examined the interaction of CETP TaqB1 polymorphism with dietary insulin index and load (DII and DIL), in altering on CVD risk factors among type 2 diabetes mellitus (T2DM). In this cross-sectional study, blood samples were collected from 220 type 2 diabetic patients (134 females and 86 male) with a mean age of 52.24 years in Tehran, Iran. DIL and DII were obtained via validated food-frequency questionnaire (FFQ). Taq1B polymorphism was genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Biochemical markers including total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), superoxide dismutase (SOD), C-reactive protein (CRP), total antioxidant capacity (TAC), pentraxin-3 (PTX3), isoprostaneF2α (PGF2α). interleukin 18 (IL18), leptin and ghrelin were measured by standard protocol. Patients with B1B1 genotype had lower lipid profiles include LDL/HDL (P < 0.001) and TG (P = 0.04) when they consumed diets higher on the DIL and DII index. Moreover, carriers of B2B2 genotype who were in the last tertile of DIL had higher antioxidant and inflammatory markers include SOD (P = 0.01), PGF2α (P = 0.04) and CRP (P = 0.02). Further, a significant interaction between CETP TaqB1 and DII was shown in terms of WC (P = 0.01), where the highest WC were observed in B2B2 genotype carriers following a DII score. However, the highest inflammatory and antioxidant markers include CRP (P = 0.04), TAC (P = 0.01), SOD (P = 0.02), and PGF2α (P = 0.02) were observed in B2B2 genotype carriers when they consumed diets higher on the DII index. Based on the current study, it could be proposed that CETP polymorphism may be associated with CVD risk factors in T2DM patients with high following insulin indices, including DII and DIL. It seems that CETP Taq1B polymorphism can invert the result produced by insulin. This conclusion illustrates that the CETP Taq1B B1 allele could counteract the CVD risk induced by high DII and DIL.

Quantile-specific heritability of total cholesterol and its pharmacogenetic and nutrigenetic implications

BACKGROUND

"Quantile-dependent expressivity" occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g. cholesterol) is high or low relative to its distribution. We have previously shown that the effect of a 52-SNP genetic-risk score was 3-fold larger at the 90th percentile of the total cholesterol distribution than at its 10th percentile. The objective of this study is to assess quantile-dependent expressivity for total cholesterol in 7006 offspring with parents and 2112 sibships from Framingham Heart Study.

METHODS

Quantile-specific heritability (h2) was estimated as twice the offspring-parent regression slope as robustly estimated by quantile regression with nonparametric significance assigned from 1000 bootstrap samples.

RESULTS

Quantile-specific h2 increased linearly with increasing percentiles of the offspring's cholesterol distribution (P = 3.0 × 10-9), i.e. h2 = 0.38 at the 10th percentile, h2 = 0.45 at the 25th percentile, h2 = 0.52 at the 50th, h2 = 0.61 at the 75th percentile, and h2 = 0.65 at the 90th percentile of the total cholesterol distribution. Average h2 decreased from 0.55 to 0.34 in 3564 offspring who started cholesterol-lowering medications, but this was attributable to quantile-dependent expressivity and the offspring's 0.94 mmol/L average drop in total cholesterol. Quantile-dependent expressivity likely explains the reported effect of the CELSR2/PSRC1/SORT1 rs646776 and APOE rs7412 gene loci on statin efficacy. Specifically, a smaller genetic effect size at the lower (post-treatment) than higher (pre-treatment) cholesterol concentrations mandates that the trajectories of the genotypes cannot move in parallel when cholesterol is decreased pharmacologically.

CONCLUSION

Cholesterol concentrations exhibit quantile-dependent expressivity, which may provide an alternative interpretation to pharmacogenetic and nutrigenetic interactions.

Quantile-Dependent Expressivity and Gene-Lifestyle Interactions Involving High-Density Lipoprotein Cholesterol

BACKGROUND

The phenotypic expression of a high-density lipoprotein (HDL) genetic risk score has been shown to depend upon whether the phenotype (HDL-cholesterol) is high or low relative to its distribution in the population (quantile-dependent expressivity). This may be due to the effects of genetic mutations on HDL-metabolism being concentration dependent.

METHOD

The purpose of this article is to assess whether some previously reported HDL gene-lifestyle interactions could potentially be attributable to quantile-dependent expressivity.

SUMMARY

Seventy-three published examples of HDL gene-lifestyle interactions were interpreted from the perspective of quantile-dependent expressivity. These included interactive effects of diet, alcohol, physical activity, adiposity, and smoking with genetic variants associated with the ABCA1, ADH3, ANGPTL4, APOA1, APOA4, APOA5, APOC3, APOE, CETP, CLASP1, CYP7A1, GALNT2, LDLR, LHX1, LIPC, LIPG, LPL, MVK-MMAB, PLTP, PON1, PPARα, SIRT1, SNTA1,and UCP1genes. The selected examples showed larger genetic effect sizes for lifestyle conditions associated with higher vis-à-vis lower average HDL-cholesterol concentrations. This suggests these reported interactions could be the result of selecting subjects for conditions that differentiate high from low HDL-cholesterol (e.g., lean vs. overweight, active vs. sedentary, high-fat vs. high-carbohydrate diets, alcohol drinkers vs. abstainers, nonsmokers vs. smokers) producing larger versus smaller genetic effect sizes. Key Message: Quantile-dependent expressivity provides a potential explanation for some reported gene-lifestyle interactions for HDL-cholesterol. Although overall genetic heritability appears to be quantile specific, this may vary by genetic variant and environmental exposure.

The combined effects of cholesteryl ester transfer protein (CETP) TaqIB gene polymorphism and canola, sesame and sesame-canola oils consumption on metabolic response in patients with diabetes and healthy people

Introduction: Cholesteryl ester transfer protein (CETP) is a key regulating enzyme in the lipid metabolism pathway, and its gene polymorphism may be a candidate for modulating the metabolic responses to dietary intervention. We thus examined whether the effects of the CETP TaqIB polymorphism on metabolic profiles were modified by dietary plant oils. Methods: This is a retrospective analysis of data collected during a randomized triple-blind cross over trial. A total of 95 patients with type 2 diabetes and 73 non-diabetes individuals completed a 9-weekof the intake of sesame, canola and sesame-canola oils. Blood samples were collected at the beginning and at the end of each intervention period for biochemical analysis. Genotyping was done using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: In diabetes patients, B1B1 homozygotes of the CETP TaqIB polymorphism compared with B2 carriers (B1B2 + B2B2) had significantly lower diastolic blood pressure, apoB and apoB: apoA-1,and higher Lp(a) after the intake of sesame-canola oil, as well as lower insulin and HOMA-IR after the intake of sesame oil. There was also a significant effect of genotype on adjusted changes of apoB, apoB: apoA-1, insulin, HOMA-IR and QUICKI. A significant genotype-dietary oils combined effects were observed for diastolic blood pressure, and LDL: HDL, TC: HDL and TG: HDL ratios in diabetes patients. No independent or combined effects of dietary oils and genotypes on outcomes were found in healthy people. Conclusion: There was a modulatory effect of the CETP TaqIB polymorphism on some metabolic traits in response to plant oils in patients with diabetes. Taken together, the intake of sesame-canola and canola oils showed more favorable effects in diabetes patients with B1B1 genotype. Future investigations are needed to confirm these results.

Genetic variations of cholesteryl ester transfer protein and diet interactions in relation to lipid profiles and coronary heart disease: a systematic review

Data on diet–genotype interactions in the prevention or treatment of dyslipidemia have increased remarkably. This systematic review aimed to assess nutrigenetic studies regarding the modulating effect of diet on cholesteryl ester transfer protein (CETP) polymorphisms in relation to metabolic traits.

Data were collected through studies published between 2000 and SEP. 2016 using five electronic databases. The quality of eligible studies was assessed using a 12-item quality checklist, derived from the STrengthening the REporting of Genetic Association Studies (STREGA) statement. CETP variants that had associations with lipid profiles in previous studies were extracted for drawing of the linkage disequilibrium (LD) plot.

Among CETP variants, the rs9989419 best represented this genome wide association signal across all populations, based on LD r² estimates from 1000 genomes references. In the 23 found eligible studies (clinical trials and observational), the TaqIB and I405V polymorphisms were the two most intensively studied. Two studies reported the effect of interaction between rs3764261 and diet on lipid levels. Regarding the rs708272 (Taq1B), individuals with the B1 risk allele showed better responses to dietary interventions than those with B2B2 genotype, whereas with I405V, inconsistent results have been reported. Modest alcohol consumption was associated with decreased risk of coronary heart disease among B2 carriers of rs708272.

It is concluded that variations in the CETP gene may modulate the effects of dietary components on metabolic traits. These results have been controversial, indicating complex polygenic factors in metabolic response to diet and lack of uniformity in the study conditions and designs.

High-Carbohydrate/Low-Fat Diet-Induced Gender-Specific Serum Lipid Profile Changes Are Associated with LEPR Polymorphisms in Chinese Youth

BACKGROUND/AIMS

The study aimed to investigate the interactions of genetic variants in the leptin receptor (LEPR) gene with lipid profile changes following a high-carbohydrate/low-fat (HC/LF) diet in a Chinese Han population.

METHODS

Fifty-six healthy young subjects were given washout diets, followed by HC/LF diets consisting of 15% fat and 70% carbohydrate for 6 days. Serum lipid profiles and insulin levels before and after HC/LF diets were analyzed.

RESULTS

Statistically elevated high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-1 (apoA-I), and insulin levels were only observed in the GG genotype of LEPR Lys109Arg but not in the A carriers after HC/LF diet. When gender was taken into account, significantly increased HDL-C, apoA-I, and insulin levels were found in women with the GG genotype. Moreover, lower low-density lipoprotein cholesterol (LDL-C) and higher insulin levels were only observed in subjects with the GG genotype of LEPR Gln223Arg, while higher HDL-C and apoA-I were only found in the A allele carriers. Additionally, the lower LDL-C and body mass index (BMI), and higher HDL-C and insulin levels were only observed in subjects with the GG genotype of LEPR Lys656Asn.

CONCLUSIONS

LEPR polymorphisms contribute to the heterogeneities in BMI, LDL-C, and HDL-C responsiveness that are induced by a HC/LF diet in healthy young Chinese adults.

Nutrigenetics of cholesterol metabolism: observational and dietary intervention studies in the postgenomic era

Cholesterol metabolism is a well-defined responder to dietary intakes and a classic biomarker of cardiovascular health. For this reason, circulating cholesterol levels have become key in shaping nutritional recommendations by health authorities worldwide for better management of cardiovascular disease, a leading cause of mortality and one of the most costly health problems globally. Data from observational and dietary intervention studies, however, highlight a marked between-individual variability in the response of cholesterol metabolism to similar dietary protocols, a phenomenon linked to genetic heterogeneity. This review summarizes the postgenomic evidence of polymorphisms within cholesterol-associated genes relative to fasting circulating cholesterol levels under diverse nutritional conditions. A number of cholesterol-related gene-diet interactions are confirmed, which may have clinical importance, supporting a deeper look into the rapidly emerging field of nutrigenetics for meaningful conclusions that may eventually lead to genetically targeted dietary recommendations in the era of personalized nutrition.

Associations of lipoprotein lipase gene rs326 with changes of lipid profiles after a high-carbohydrate and low-fat diet in healthy Chinese Han youth

To investigate the effects of a high-carbohydrate and low-fat (HC/LF) diet on plasma lipids and apolipoproteins (Apos) of healthy Chinese Han youth with different genotypes of lipoprotein lipase gene (LPL) rs326, 56 subjects were given a washout diet of 30.1% fat and 54.1% carbohydrate for seven days, followed by the HC/LF diet of 13.8% fat and 70.1% carbohydrate for six days, with no total energy restriction. Plasma glucose, triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), Apo B-100 and Apo A-I were analyzed at baseline and before and after the HC/LF diet. The results show that, when compared with before the HC/LF diet, only the male G carriers experienced increased HDL-C (p = 0.008) and Apo A-I (p = 0.005) after the HC/LF diet. Decreased TC in both males and females and increased TG in females were found regardless of the genotype after the HC/LF diet. LDL-C decreased in all the subjects although the decrease was not significant in the female G carriers. These results demonstrate that the G allele of LPL rs326 associates with the elevated levels of HDL-C and Apo A-I after the HC/LF diet in males of the healthy Chinese Han Youth.

Effects of R219K polymorphism of ATP-binding cassette transporter 1 gene on serum lipids ratios induced by a high-carbohydrate and low-fat diet in healthy youth

Background

Diets are the important players in regulating plasma lipid profiles. And the R219K polymorphism at the gene of ATP-binding cassette transporter 1(ABCA1) was reported to be associated with the profiles. However, no efforts have been made to investigate the changes of lipid profiles after a high-carbohydrate and low-fat diet in different subjects with different genotypes of this polymorphism. This study was to evaluate the effects of ABCA1 R219K polymorphism on serum lipid and apolipoprotein (apo) ratios induced by a high-carbohydrate/low-fat (high-CHO) diet. After a washout diet of 54.1% carbohydrate for 7 days, 56 healthy young subjects (22.89 ± 1.80 years old) were given a high-CHO diet of 70.1% carbohydrate for 6 days. Height, weight, waist circumference, hip circumference, glucose (Glu), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apoA-1 and apoB-100 were measured on the 1^st, 8^th and 14^th days of this study. Body mass index (BMI), waist-to-hip ratios (WHR), log(TG/HDL-C), TC/HDL-C, LDL-C/HDL-C and apoA-1/apoB-100 were calculated. ABCA1 R219K was analyzed by a PCR-RFLP method.

Results

The results indicate that the male subjects of all the genotypes had higher WHR than their female counterparts on the 1^st, 8^th and 14^th days of this study. The male K carriers had higher log(TG/HDL-C) and TC/HDL-C than the female carriers on the 1^st and 14^th days, and higher LDL-C/HDL-C on the 14^th day. When compared with that on the 8^th day, TC/HDL-C was decreased regardless of the genotypes and genders on the 14^th day. Log(TG/HDL-C) was increased in the males with the RR genotype and the female K carriers. Lowered BMI, Glu and LDL-C/HDL-C were found in the male K carriers, but only lowered BMI in the female K carriers and only lowered LDL-C/HDL-C in the females with the RR genotype.

Conclusions

These results suggest that ABCA1 R219K polymorphism is associated differently in males and females with elevated log(TG/HDL-C) and decreased LDL-C/HDL-C induced by the high-CHO diet.

Taq1B polymorphism of cholesteryl ester transfer protein (CETP) in Egyptian patients with metabolic syndrome

AIM

We aimed at evaluation of the possible association of cholesteryl ester transfer protein (CETP) Taq1B polymorphism with the components of metabolic syndrome in a cohort of Egyptian patients compared to their healthy counterparts.

PATIENTS AND METHODS

Blood samples were collected for lipid profile, fasting glucose, insulin and routine biochemical tests. The Taq1B genotypes of CETP were determined using RFLP-PCR technique.

RESULTS

The patients group showed a significantly higher B1B1 genotype and lower B2B2 genotype compared to the controls group. Serum HDL-C level was significantly higher in all subjects with the B2B2 genotype compared to those with B1B1 genotype. In the patients group, age positively correlated with cholesterol level, triglycerides, BMI and waist circumference.

CONCLUSION

Egyptian patients affected with metabolic syndrome have a higher prevalence of B1B1 genotype that is associated with lower serum HDL-C levels.