Contribution of APOA5-1131C allele to the increased susceptibility of diabetes mellitus in association with higher triglyceride in Korean women

Homeostasis Model Assessment for Insulin Resistance Mediates the Positive Association of Triglycerides with Diabetes

Elevated circulating triglyceride levels have been linked to an increased risk of diabetes, although the precise mechanisms remain unclear. This study aimed to investigate whether low-density lipoprotein (LDL) cholesterol, homeostatic model assessment (HOMA) for insulin resistance, and C-reactive protein (CRP) served as mediators in this association across a sample of 18,435 US adults. Mediation analysis was conducted using the PROCESS Version 4.3 Macro for SPSS. Simple mediation analysis revealed that all three potential mediators played a role in mediating the association. However, in parallel mediation analysis, where all three mediators were simultaneously included, HOMA for insulin resistance remained a significant mediator (indirect effect coefficient, 0.47; 95% confidence interval [CI], 0.43-0.52; p < 0.05) after adjusting for all tested confounding factors. Conversely, LDL cholesterol (indirect effect coefficient, -0.13; 95% CI, -0.31-0.05; p > 0.05) and C-reactive protein (indirect effect coefficient, 0.01; 95% CI, -0.003-0.02; p > 0.05) ceased to be significant mediators. HOMA for insulin resistance accounted for 49% of the association between triglycerides and diabetes. In conclusion, HOMA for insulin resistance was the dominant mediator underlying the association between triglycerides and diabetes. Therefore, reducing triglyceride levels may hold promise for improving insulin sensitivity in diabetic patients.

Lipid-Related Genetic Variants for Personalized Dietary Interventions: A Systematic Review

Dyslipidemias are known risk factors for chronic diseases. Precision nutrition interventions are designed according to characteristics, such as diet, phenotype, and genotype. This systematic review aims to define a panel of genetic variants associated with lipid abnormalities that could be later used in nutrigenetic intervention studies. A systematic review is conducted following the PRISMA-P. Studies published from January 2010 to December 2020 in English language and humans are included from PubMed and ScienceDirect databases. Articles that demonstrate a strong association between polymorphisms (single nucleotide variation) of genes involved in lipid metabolism and increased risk for dyslipidemia are included. A total of 3031 articles are screened, but only 51 articles fulfill the inclusion criteria. The genes included are FABP2, MTTP related to CM synthesis and secretion; LPL, LIPC involved in triglyceride hydrolysis; CETP, APOA1, LCAT, ABCA1, and APOA5 related to lipoprotein metabolism, and APOE, LDLR, SCARB1, APOC3 involved in lipid clearance. In this systematic review, genetic variants related to chylomicron synthesis, triglyceride hydrolysis, lipoprotein metabolism, and lipid clearance demonstrate a strong association with lipid abnormalities, which can be used to design precision nutrition interventions that may help to prevent and treat dyslipidemia effectively.

Trends in Prevalence of Hypertriglyceridemia and Related Factors in Korean Adults: A Serial Cross-Sectional Study

Objective

We aimed to investigate the longitudinal trends in prevalence of hypertriglyceridemia in Korean adults and hypertriglyceridemia-associated lifestyle habits, socioeconomic factors and comorbidities.

Methods

Data from the 2007-2020 Korea National Health and Nutrition Examination Survey (KNHANES) were used in this study. Two cutoff values (≥150 mg/dL and ≥200 mg/dL) for fasting serum triglyceride levels were used to estimate the age- and sex-specific prevalence of hypertriglyceridemia. Use of lipid-lowering medications, lifestyle factors such as smoking, alcohol consumption, and regular exercise, socioeconomic variables such as educational attainment and household income, and comorbidities such as obesity, abdominal obesity, hypertension, and diabetes mellitus were also investigated.

Results

The prevalence of hypertriglyceridemia among Koreans based on KNHANES 2007-2020 was 29.6% at ≥150 mg/dL and 16.1% at ≥200 mg/dL. While the rate of using lipid-lowering medications increased steadily from 2007 to 2020, changes in annual prevalence of hypertriglyceridemia were subtle. The prevalence of hypertriglyceridemia in men peaked in middle age (47.7% and 30.0% for ≥150 mg/dL and ≥200 mg/dL, respectively, in their 40s), but its prevalence in women increased throughout their lifetime (32.6% and 14.7% for ≥150 mg/dL and ≥200 mg/dL, respectively, in their 70s). Smoking and high-risk drinking exacerbated peak prevalence in both sexes. Young adults with any comorbidities had prominently increased prevalence of hypertriglyceridemia. The lowest levels of education and income were both associated with the higher prevalence of hypertriglyceridemia in both sexes.

Conclusion

It is important to understand the age- and sex-specific epidemiology of hypertriglyceridemia to establish its appropriate management plans.

Sex-related differences in single nucleotide polymorphisms associated with dyslipidemia in a Korean population

BACKGROUND

The prevalence of dyslipidemia has increased steadily in Korea, and the incidence of dyslipidemia differs by sex. In this study, we identified single nucleotide polymorphisms (SNPs) related to dyslipidemia in Korean cohorts through genome-wide association study (GWAS) analysis.

METHODS

Genotyping was conducted to determine the genotypes of 72,298 participants and investigate genotypes for 7,079,946 SNPs. Sex, age, and BMI were set as covariates for GWAS, and significant SNPs were identified in the discovery and replication stages using logistic regression.

RESULTS

GWAS of the entire cohort revealed a total of five significant SNPs: rs117026536 (LPL), rs651821 (APOA5), rs9804646 (APOA5), rs9926440 (CETP), and rs429358 (APOE). GWAS of the male subjects revealed a total of four significant SNPs. While rs9804646 (APOA5) and rs429358 (APOE) were significant for all the subjects, rs662799 (APOA5) and rs56156922 (CETP) were significant only for the male subjects. GWAS of the female subjects revealed two significant SNPs, rs651821 (APOA5) and rs9804646 (APOA5), both of which were significant in all the subjects.

CONCLUSION

This is the first study to identify sex-related differences in genetic polymorphisms in Korean populations with dyslipidemia. Further studies considering environmental variables will be needed to elucidate these sex-related genetic differences in dyslipidemia.

Association of the APOA-5 Genetic Variant rs662799 with Metabolic Changes after an Intervention for 9 Months with a Low-Calorie Diet with a Mediterranean Profile

In cross-sectional studies, the genetic variant rs662799 of the APOA5 gene is associated with high serum triglyceride concentrations, and in some studies, the effect of short-term dietary interventions has been evaluated. The aim of the present investigation was to evaluate the role of this genetic variant in metabolic changes after the consumption of a low-calorie diet with a Mediterranean pattern for 9 months. A population of 269 Caucasian obese patients was recruited. Adiposity and biochemical parameters were measured at the beginning (basal level) and after 3 and 9 months of the dietary intervention. The rs662799 genotype was assessed with a dominant analysis (TT vs. CT + CC). The APOA5 variant distribution was: 88.1% (n = 237) (TT), 11.5% (n = 31) (TC) and 0.4% (n = 1) (CC). There were significant differences only in triglyceride levels at all times of the study between the genotype groups. After 3 and 9 months of dietary intervention, the following parameters improved in both genotype groups: adiposity parameters, systolic pressure, total cholesterol, LDL cholesterol, leptin, adiponectin and the leptin/adiponectin ratio. The intervention significantly decreased insulin levels, HOMA-IR and triglyceride levels in non-C allele carriers (Delta 9 months TT vs. TC + CC). i.e., insulin levels (delta: −3.8 + 0.3 UI/L vs. −1.2 + 0.2 UI/L; p = 0.02), HOMA-IR levels (delta: −1.2 + 0.2 units vs. −0.3 + 0.1 units; p = 0.02), triglyceride levels (delta: −19.3 + 4.2 mg/dL vs. −4.2 + 3.0 mg/dL; p = 0.02). In conclusion, non-C allele carriers of rs662799 of the APOA5 gene showed a decrease of triglyceride, insulin and HOMA-IR levels after consuming a low-calorie diet with a Mediterranean pattern; we did not observe this effect in C allele carriers, despite a significant weight loss.

Higher fasting triglyceride predicts higher risks of diabetes mortality in US adults

BACKGROUND

It is unknown whether higher triglyceride results in higher mortality from diabetes, i.e., diabetes mortality. This study aimed to investigate the association of fasting triglyceride with diabetes mortality.

METHODS

This study included 26,582 US adults from the National Health and Nutrition Examination Surveys from 1988 to 2014. Diabetes mortality outcomes were ascertained by linkage to the National Death Index records. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of triglyceride for diabetes mortality.

RESULTS

Higher levels of fasting triglyceride were associated with higher levels of glucose, glycated hemoglobin, insulin, and homeostatic model assessment for insulin resistance at baseline. A 1-natural-log-unit increase in triglyceride (e.g., from 70 to 190 mg/dL) was associated with a 115% higher multivariate-adjusted risk of diabetes diagnosis (odds ratio, 2.15; 95% CI, 2.00-2.33). During 319,758 person-years of follow-up with a mean follow-up of 12.0 years, 582 diabetes deaths were documented. Compared with people with triglyceride in the lowest quintile, people with triglyceride in the highest quintile had an 85% higher risk of diabetes mortality (HR, 1.85; 95% CI, 1.25-2.73). A 1-natural-log-unit increase in triglyceride was associated with a 40% higher multivariate-adjusted risk of diabetes mortality. The positive association between triglyceride and diabetes mortality was also presented in sub-cohorts of participants with or without diabetes.

CONCLUSIONS

This study demonstrated that higher fasting triglyceride was associated with a higher diabetes mortality risk.

APOA-5 Genetic Variant rs662799: Role in Lipid Changes and Insulin Resistance after a Mediterranean Diet in Caucasian Obese Subjects

Background and Aims

This APOA5-1131C allele is related with a higher serum triglyceride levels and perhaps a different metabolic response to a dietary intervention. The aim of the present investigation was to evaluate SNP rs662799 in the APOA5 gene and its associations with metabolic effects after a hypocaloric diet with Mediterranean pattern.

Methods

A population of 363 Caucasian obese patients was enrolled. Anthropometric parameters and serum parameters (lipid profile, insulin, homeostasis model assessment (HOMA-IR), glucose, C reactive protein, adiponectin, resistin, and leptin levels) were measured, at basal time and after 3 months. All patients were genotyped in the rs662799 polymorphism.

Results

The APOA5 variant distribution was as follows: 89.3% (n = 324) (TT) were homozygous for the T allele, 10.5% (n = 38) (TC) were heterozygous, and 0.2% (n = 1) (CC) were homozygous for the C allele. Triglyceride levels were higher in patients with the C allele. After dietary intervention, BMI, weight, fat mass, waist circumference, systolic blood pressure, adiponectin, leptin, and adiponectin/leptin ratio improved significantly in both genotype groups TT and TC+CC. After dietary intervention, insulin levels (delta: −3.6 ± 0.8 UI/L vs. −1.5 ± 0.6 UI/L; P = 0.03), HOMA-IR (delta: −1.5 ± 0.4 units vs. −0.3 ± 0.2 units; P = 0.02), and triglyceride levels (delta: −19.3 ± 4.2 mg/dL vs. −3.2 ± 3.1 mg/dL; P = 0.02) decreased in non-C allele carriers.

Conclusions

C allele carriers of rs662799 of the APOA5 gene did not show an improvement in triglyceride, insulin, and HOMA-IR levels after a significant weight loss due to a hypocaloric diet with a Mediterranean pattern.

APOA5 Variant rs662799, Role in Cardiovascular Traits and Serum Adipokine Levels in Caucasian Obese Subjects

BACKGROUND AND AIMS

This ApoA5-1131C allele of rs662799 variant is related with a higher serum triglyceride levels, and it contributes to increase risk of cardiovascular disease. The aim of the present investigation was to evaluate single nucleotide polymorphism rs662799 in APOA5 gene and its associations with cardiovascular risk factors, MS, and serum adipokine levels.

METHODS

The study involved a population of 1,002 Caucasian obese subjects. Measurements of body weight, waist circumference, fat mass, arterial blood pressure, blood glucose, C-reactive protein, insulin levels, insulin resistance (HOMA-IR), lipid profile, and adipokines levels were recorded. Genotype of ApoA5 gene polymorphism (rs662799) and prevalence of metabolic syndrome (MS) were evaluated.

RESULTS

The distribution of the rs662799 polymorphism in this adult population (n = 1,002) was 88.3% (n = 885) (TT), 11.4% (n = 114) (TC), and 0.3% (n = 3) (CC). No significant differences were found between the 2 genotypes in the anthropometric data, MS, or blood pressure. Triglyceride levels were higher in C-allele carriers (delta total group: 19.7 ± 2.1 mg/dL: p = 0.02) than non C-allele carriers. HDL-cholesterol levels were lower in C-allele carriers (delta total group: -6.7 ± 1.1 mg/dL: p = 0.02) than non C-allele carriers. Adiponectin levels were lower in C-allele carriers (delta total group: -11.6 ± 1.0 mg/dL: p = 0.02) too. In C-allele carriers, logistic regression analysis showed an increased risk of hypertriglyceridemia (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.2-3.4, p = 0.001) and percentage of low-HDL-C (OR = 2.2, 95% CI = 1.3-3.7, p = 0.002) after adjusting by body mass index and age.

CONCLUSIONS

C-allele carriers of rs662799 of APOA5 gene showed high rates of low levels of HDL and hypertriglyceridemia, with differences in triglyceride, HDL cholesterol, and adiponectin levels in Caucasian obese subjects.

Apolipoprotein A5 3'-UTR variants and cardiometabolic traits in Koreans: results from the Korean genome and epidemiology study and the Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES

This study aimed to test the association between APOA5 3'-UTR variants (rs662799) and cardiometabolic traits in Koreans.

SUBJECTS/METHODS

For this study, epidemiological data, Apolipoprotein A5 (APOA5) genotype information, and lymphoblastoid cell line (LCL) biospecimens from a subset of the Ansung-Ansan cohort within the Korean Genome and Epidemiology study (KoGES-ASAS; n = 7,704) as well as epidemiological data along with genomic DNA biospecimens of participants from a subset of the Korea National Health and Nutrition Examination Survey (KNHANES 2011-12; n = 2,235) were obtained. APOA5 mRNA expression was also measured.

RESULTS

APOA5 rs662799 genotype distributions in both the KoGES-ASAS and KNHANES groups were 50.6% for TT, 41.3% for TC, and 8.1% for CC, which are similar to those in previous reports. In both groups, minor C allele carriers, particularly subjects with CC homozygosity, had lower high-density lipoprotein (HDL) cholesterol and higher triglyceride levels than TT homozygotes. Linear regression analysis showed that the minor C allele significantly contributed to reduction of circulating HDL cholesterol levels [β = −2.048, P < 0.001; β = −2.199, P < 0.001] as well as elevation of circulating triglyceride levels [β = 0.053, P < 0.001; β = 0.066, P < 0.001] in both the KoGES-ASAS and KNHANES groups. In addition, higher expression levels of APOA5 in LCLs of 64 healthy individuals were negatively associated with body mass index (r = −0.277, P = 0.027) and circulating triglyceride level (r = −0.340, P = 0.006) but not significantly correlated with circulating HDL cholesterol level. On the other hand, we observed no significant difference in the mRNA level of APOA5 according to APOA5 rs662799 polymorphisms.

CONCLUSIONS

The C allele of APOA5 rs662799 was found to be significantly associated with cardiometabolic traits in a large Korean population from the KoGES-ASAS and KNHANES. The effect of this genotype may be associated with post-transcriptional regulation, which deserves further experimental confirmation.

A promoter variant of the APOA5 gene increases atherogenic LDL levels and arterial stiffness in hypertriglyceridemic patients

Hypertriglyceridemia is recognized as an independent risk factor for coronary artery disease. The apolipoprotein A5 gene (APOA5) is a key regulator of triglyceride levels. We aimed to evaluate the associations of single nucleotide polymorphisms (SNPs) in APOA5, including -1131T>C and c.553G>T, with hypertriglyceridemia, apoA5 concentrations, atherogenic LDL cholesterol levels, and arterial stiffness in hypertriglyceridemic patients. The study population included 599 hypertriglyceridemic patients (case) and 1,549 untreated normotriglyceridemic subjects (control). We genotyped two APOA5 variants, -1131T>C (rs662799) and c.553G>T (rs2075291). The frequencies of the CC genotype of -1131T>C (0.165) and the T allele of c.553G>T (0.119) were significantly higher in hypertriglyceridemic patients than in normotriglyceridemic subjects (0.061 and 0.070, respectively; all p<0.001). In the control and case groups, both the -1131T>C and c.553G>T variants were associated with higher triglyceride and lower HDL cholesterol levels. Controls with the -1131CC variant had lower apoA5 concentrations than controls with the -1131TT variant. Similar effects of the -1131T>C variant on apoA5 were observed in the cases. In the hypertriglyceridemic group, the -1131T>C variant was associated with a smaller LDL particle size, higher levels of oxidized LDL and malondialdehyde, and higher brachial-ankle pulse wave velocity. The -1131T>C and c.553G>T polymorphisms were associated with hypertriglyceridemia in the study population, but only the -1131T>C polymorphism directly affected apoA5 concentrations. Hypertriglyceridemic patients carrying the APOA5 -1131T>C polymorphism exhibited increased atherogenic LDL levels and arterial stiffness, probably due to an effect of the -1131T>C polymorphism on apoA5 concentrations.

Apolipoprotein A5 fifteen years anniversary: Lessons from genetic epidemiology

Apolipoprotein A5 (APOA5) is a small protein, expressed predominantly in the liver. In plasma, it is located on triglyceride rich lipoprotein particles (chylomicrones and VLDL) and on HDL. Plasma concentration of apolipoprotein A5 is very low, suggesting rather regulatory (activation of lipoprotein lipase, …) than structural function. APOA5 is an important determinant of plasma triglyceride concentration; this effect has been confirmed both on animal models, as well as on human studies. Minor alleles of three commonly analysed variants within this gene (rs662799, rs3135506, rs2075291) are associated with higher plasma TG values and increased risk of myocardial infarction, with some important interethnic differences observed. Further roles of APOA5; determination of BMI, diabetes and last but not least nutri- and pharmaco-genetic interactions are suggested, but without the definitive conclusions.

Genetic association of APOA5 and APOE with metabolic syndrome and their interaction with health-related behavior in Korean men

BACKGROUND

Genome-wide association studies have been used extensively to identify genetic variants linked to metabolic syndrome (MetS), but most of them have been conducted in non-Asian populations. This study aimed to evaluate the association between MetS and previously studied single nucleotide polymorphisms (SNPs), and their interaction with health-related behavior in Korean men.

METHODS

Seventeen SNPs were genotyped and their association with MetS and its components was tested in 1193 men who enrolled in the study at Seoul National University Hospital.

RESULTS

We found that rs662799 near APOA5 and rs769450 in APOE had significant association with MetS and its components. The SNP rs662799 was associated with increased risk of MetS, elevated triglyceride (TG) and low levels of high-density lipoprotein, while rs769450 was associated with a decreased risk of TG. The SNPs showed interactions between alcohol drinking and physical activity, and TG levels in Korean men.

CONCLUSIONS

We have identified the genetic association and environmental interaction for MetS in Korean men. These results suggest that a strategy of prevention and treatment should be tailored to personal genotype and the population.

Association of apolipoprotein A5 gene -1131T>C polymorphism with the risk of metabolic syndrome in Korean subjects

We assessed the associations between the APOA5  −1131T>C polymorphism and lipid parameters and other risk factors of the metabolic syndrome in Korean subjects. A total of 2,901 participants from 20 oriental medical hospitals in Korea were enrolled between 2006 and 2011. According to the modified National Cholesterol Education Program Adult Treatment Panel III definitions, subjects were classified into the metabolic syndrome group and control group. The APOA5  −1131T>C genotype was significantly associated with serum high-density lipoprotein cholesterol levels (effect = − 1.700 mg/dL, P=6.550-E07) in the total study population after adjustment for differences in age and gender. The association of the APOA5  −1131T>C genotype with serum log-transformed triglyceride was also significant in an additive genetic model (effect = 0.056 mg/dL, P=2.286E-19). After adjustment for age and gender, we determined that the odds ratio for the occurrence of the metabolic syndrome was 1.322 for C-allele carriers in the additive model (95% CI = [1.165 − 1.501], P=1.48E-05). In the current study, we demonstrated that the APOA5  −1131T>C polymorphism is associated with the metabolic syndrome because of its remarkable effect on serum triglyceride levels in Korean subjects.

Association of the Apolipoprotein A5 Gene -1131T>C Polymorphism with Serum Lipids in Korean Subjects: Impact of Sasang Constitution

Apolipoprotein A5 (APOA5) was identified as a strong modulator of serum lipids. Moreover, an APOA5 gene −1131T>C polymorphism has been associated with serum lipids, but the results are inconsistent according to ethnic and racial groups. We have genotyped and analyzed 1,619 outpatients of Korean oriental medicine hospitals who were classified into three Sasang constitution groups (SCGs), So-Yang (SY), So-Eum (SE), and Tae-Eum (TE). There were no significant difference in the distribution of the APOA5 −1131T>C genotype among the three SCGs. Subjects with the C allele in SY and TE showed significantly lower serum high-density lipoprotein cholesterol (HDL-C) and higher triglyceride (TG) levels than noncarriers of the C allele. These results show the differences in the prevalence of decreasing serum HDL-C and elevating serum TG levels along with APOA5 −1131T>C polymorphism according to SCG and suggest that SCG may act as a significant risk factor for hypo-HDL-C-emia and hypertriglyceridemia susceptibility.