Association of ApoE gene polymorphisms with serum lipid levels and the risk of type 2 diabetes mellitus in the Chinese Han population of central China

The Apo gene's genetic variants: hidden role in Asian vascular risk

Vascular risk factors, including diabetes, hypertension, hyperlipidemia, and obesity, pose significant health threats with implications extending to neuropsychiatric disorders such as stroke and Alzheimer's disease. The Asian population, in particular, appears to be disproportionately affected due to unique genetic predispositions, as well as epigenetic factors such as dietary patterns and lifestyle habits. Existing management strategies often fall short of addressing these specific needs, leading to greater challenges in prevention and treatment. This review highlights a significant gap in our understanding of the impact of genetic screening in the early detection and tailored treatment of vascular risk factors among the Asian population. Apolipoprotein, a key player in cholesterol metabolism, is primarily associated with dyslipidemia, yet emerging evidence suggests its involvement in conditions such as diabetes, hypertension, and obesity. While genetic variants of vascular risk are ethnic-dependent, current evidence indicates that epigenetics also exhibits ethnic specificity. Understanding the interplay between Apolipoprotein and genetics, particularly within diverse ethnic backgrounds, has the potential to refine risk stratification and enhance precision in management. For Caucasian carrying the APOA5 rs662799 C variant, pharmacological interventions are recommended, as dietary interventions may not be sufficient. In contrast, for Asian populations with the same genetic variant, dietary modifications are initially advised. Should dyslipidemia persist, the consideration of pharmaceutical agents such as statins is recommended.

Apolipoprotein E E3/E4 genotype is associated with an increased risk of type 2 diabetes mellitus complicated with coronary artery disease

OBJECTIVE

Dyslipidemia is a co-existing problem in patients with diabetes mellitus (DM) and coronary artery disease (CAD), and apolipoprotein E (APOE) plays an important role in lipid metabolism. However, the relationship between the APOE gene polymorphisms and the risk of developing CAD in type 2 DM (T2DM) patients remains controversial. The aim of this study was to assess this relationship and provide a reference for further risk assessment of CAD in T2DM patients.

METHODS

The study included 378 patients with T2DM complicated with CAD (T2DM + CAD) and 431 patients with T2DM alone in the case group, and 351 individuals without DM and CAD were set as controls. The APOE rs429358 and rs7412 polymorphisms were genotyped by polymerase chain reaction (PCR) - microarray. Differences in APOE genotypes and alleles between patients and controls were compared. Multiple logistic regression analysis was performed after adjusting for age, gender, body mass index (BMI), history of smoking, and history of drinking to access the relationship between APOE genotypes and T2DM + CAD risk.

RESULTS

The frequencies of the APOE ɛ3/ɛ4 genotype and ε4 allele were higher in the T2DM + CAD patients, and the frequencies of the APOE ɛ3/ɛ3 genotype and ε3 allele were lower than those in the controls (all p < 0.05). The T2DM + CAD patients with ɛ4 allele had higher level in low-density lipoprotein cholesterol (LDL-C) than those in patients with ɛ2 and ɛ3 allele (p < 0.05). The results of logistic regression analysis showed that age ≥ 60 years old, and BMI ≥ 24.0 kg/m2 were independent risk factors for T2DM and T2DM + CAD, and APOE ɛ3/ɛ4 genotype (adjusted odds ratio (OR) = 1.93, 95% confidence interval (CI) = 1.18-3.14, p = 0.008) and ɛ4 allele (adjusted OR = 1.97, 95% CI = 1.23-3.17) were independent risk factors for T2DM + CAD. However, the APOE genotypes and alleles were not found to have relationship with the risk of T2DM.

CONCLUSIONS

APOE ε3/ε4 genotype and ε4 allele were independent risk factors for T2DM complicated with CAD, but not for T2DM.

Sequence Analysis of Six Candidate Genes in Miniature Schnauzers with Primary Hypertriglyceridemia

Miniature Schnauzers are predisposed to primary hypertriglyceridemia (HTG). In this study, we performed whole genome sequencing (WGS) of eight Miniature Schnauzers with primary HTG and screened for risk variants in six HTG candidate genes: LPL, APOC2, APOA5, GPIHBP1, LMF1, and APOE. Variants were filtered to identify those present in ≥2 Miniature Schnauzers with primary HTG and uncommon (<10% allele frequency) in a WGS variant database including 613 dogs from 61 other breeds. Three variants passed filtering: an APOE TATA box deletion, an LMF1 intronic SNP, and a GPIHBP1 missense variant. The APOE and GPIHBP1 variants were genotyped in a cohort of 108 Miniature Schnauzers, including 68 with primary HTG and 40 controls. A multivariable regression model, including age and sex, did not identify an effect of APOE (estimate = 0.18, std. error = 0.14; p = 0.20) or GPIHBP1 genotypes (estimate = -0.26, std. error = 0.42; p = 0.54) on triglyceride concentration. In conclusion, we did not identify a monogenic cause for primary HTG in Miniature Schnauzers in the six genes evaluated. However, if HTG in Miniature Schnauzers is a complex disease resulting from the cumulative effects of multiple variants and environment, the identified variants cannot be ruled out as contributing factors.

Relationships of apolipoprotein E genotypes with a cluster of seven in persons with type 2 diabetes

OBJECTIVE.

The objective of the study was to determine if there would be statistically significant differences or trends among apolipoprotein E genotypes (2/2, 2/3, 2/4, 3/3, 3/4, and 4/4) for each member of the cluster of seven associated with type 2 diabetes (T2D). The cluster of seven includes abdominal obesity, hypertension, platelet hyperaggregability, hyperglycemia, dyslipidemia (decreased plasma levels of high-density lipoprotein cholesterol (HDL-C) and increased plasma levels of triglycerides)), increased low-density lipoprotein (LDL) oxidation, and increased inflammation.

METHODS.

Forty-six patients with well-controlled T2D participated in the study. Abdominal obesity (assessed by waist circumference), hypertension (measured by manual sphygmomanometry), platelet hyperaggregability (measured by bleeding time), hyperglycemia (by enzymatic kit and spectrophotometry), decreased plasma levels of HDL-C and increased plasma levels of triglycerides (by enzymatic kit and spectrophotometry), increased LDL oxidation (measured by LDL conjugated dienes using spectrophotometry) and increased inflammation measured by C-reactive protein (CRP) (by EIA kit) were determined.

RESULTS.

All genotypes, except 2/2 were found in the population studied. Abdominal obesity did not vary significantly across the five genotypes. However, glucose levels trended progressively higher going from 2/3 to 2/4 to 3/4 to 4/4. Systolic blood pressure was higher in 3/4 compared to 2/4 and trended higher in 3/4 compared to 3/3. Diastolic blood pressure trended higher in 3/3 vs 2/4 and significantly higher in 3/4 compared to 2/4. Triglycerides trended higher in 3/4 vs 3/3 while HDL-C came close to trending downward in 4/4 compared to 2/4. Bleeding time was unaffected by genotype. Plasma LDL conjugated dienes trended higher in 3/4 vs 2/4 and were significantly higher in 3/4 vs 3/3. CRP trended higher in 4/4 vs 2/3.

CONCLUSION.

We can conclude that those with at least one 4 allele in the presence of another allele being 2, 3 or 4 is potentially (in the case of trends) deleterious or is deleterious in terms of hyperglycemia, hypertension (systolic and diastolic blood pressure), dyslipidemia, LDL conjugated dienes and CRP levels.

E2/E3 and E3/E4 Genotypes of the Apolipoprotein E are Associated with Higher Risk of Diabetes Mellitus in Patients with Hypertension

Objective

Apolipoprotein E (APOE) plays an important role in the lipid metabolism. APOE polymorphisms have been implicated in susceptibility to diabetes mellitus (DM). However, the association between APOE polymorphisms and the risk of DM among the hypertensive patients remains unclear. Our study aimed to evaluate this relationship to provide clues for further developing DM in hypertensive patients.

Methods

The study included 808 hypertensive patients with DM and 1226 hypertensive patients without DM as controls. The APOE 388T>C (rs429358) and 526C>T (rs7412) polymorphisms were genotyped by polymerase chain reaction (PCR) - microarray. Differences in APOE genotypes between subjects and controls were compared. To analyze the relationship between APOE genotypes and DM risk, multiple logistic regression analysis was performed after adjusting for gender, age, smoking history, and drinking history.

Results

The APOE E2/E4, E3/E3 genotype and ε2, ε3 allele frequency had significant difference between DM patients and controls (P<0.05). The DM patients with ɛ4 allele had lower level in high-density lipoprotein cholesterol (HDL-C) and higher level in apolipoprotein B (ApoB) than those with ɛ2 allele. The results of logistic regression analysis indicated that the APOE genotype of E2/E3 with adjusted OR=1.350 (95% Cl=1.009-1.806, P=0.043) and E3/E4 with adjusted OR=1.325 (95% Cl=1.034-1699, P=0.026) may be independent risk factors for DM.

Conclusion

APOE E2/E3 and E3/E4 genotypes may be risk factors for developing diabetes mellitus in hypertensive patients.