Apolipoprotein E gene polymorphism and serum lipid levels in the Guangxi Hei Yi Zhuang and Han populations

APOE gene polymorphism in ischemic stroke patients from Huizhou and its correlation with blood lipids and homocysteine

OBJECTIVES

To investigate the correlation between apolipoprotein E (APOE) gene polymorphisms and ischemic stroke and its relationship with blood lipids and homocysteine (HCY) level in Huizhou City.

MATERIALS AND METHODS

In this analytical cross-sectional study, we selected 2612 patients who underwent APOE genotyping from November 2019 to November 2021 at the Third People's Hospital of Huizhou. Among them, 2014 were ischemic stroke patients and 598 were non-stroke patients. The independent variables were ischemic stroke, different genotypes, and different alleles, while the dependent variables were blood lipid levels and HCY levels.

RESULTS

The distribution frequency of ε4 allele in stroke group was higher than that in non-stroke group (P < 0.05). Compared with ε4 allele carriers in the stroke group, the levels of lipid total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in ε2 and ε3 allele carriers were significantly lower, while the levels of high-density lipoprotein cholesterol (HDL-C) were significantly higher (P < 0.01). The levels of lipid Lipoprotein a (LPa) and small dense low-density lipoprotein (sdLDL) in ε2 allele carriers in stroke group were significantly lower than those of ε4 allele carriers (P < 0.05). Logistics regression analysis showed that age, TC, HCY level and allele ε4 were positively correlated with the risk of ischemic stroke (P < 0.01), TG level was positively correlated with the risk of ischemic stroke in females (P < 0.01).

CONCLUSIONS

APOE gene polymorphism is associated with ischemic stroke, and ε4 allele carriers have a higher risk than ε3 allele carriers.

Genetic risks of Alzheimer's by APOE and MAPT on cortical morphology in young healthy adults

Genetic risk factors such as APOE ε4 and MAPT (rs242557) A allele are associated with amyloid and tau pathways and grey matter changes at both early and established stages of Alzheimer's disease, but their effects on cortical morphology in young healthy adults remain unclear. A total of 144 participants aged from 18 to 24 underwent 3T MRI and genotyping for APOE and MAPT to investigate unique impacts of these genetic risk factors in a cohort without significant comorbid conditions such as metabolic and cardiovascular diseases. We segmented the cerebral cortex into 68 regions and calculated the cortical area, thickness, curvature and folding index for each region. Then, we trained machine learning models to classify APOE and MAPT genotypes using these morphological features. In addition, we applied a growing hierarchical self-organizing maps algorithm, which clustered the 68 regions into 4 subgroups representing different morphological patterns. Then, we performed general linear model analyses to estimate the interaction between APOE and MAPT on cortical patterns. We found that the classifiers using all cortical features could accurately classify individuals carrying genetic risks of dementia outperforming each individual feature alone. APOE ε4 carriers had a more convoluted and thinner cortex across the cerebral cortex. A similar pattern was found in MAPT A allele carriers only in the regions that are vulnerable for early tau pathology. With the clustering analysis, we found a synergetic effect between APOE ε4 and MAPT A allele, i.e. carriers of both risk factors showed the most deviation of cortical pattern from the typical pattern of that cluster. Genetic risk factors of dementia by APOE ε4 and MAPT (rs242557) A allele were associated with variations of cortical morphology, which can be observed in young healthy adults more than 30 years before Alzheimer's pathology is likely to occur and 50 years before dementia symptoms may begin.

The relationship between sleep duration and activities of daily living (ADL) disability in the Chinese oldest-old: A cross-sectional study

Objective

To investigate the relationship between sleep duration and activities of daily living (ADL) disability, and to explore the optimal sleep duration among oldest-old Chinese individuals.

Methods

In this cross-sectional study, 1,798 participants (73.2% female) were recruited from Dongxing and Shanglin in Guangxi Zhuang Autonomous Region, China in 2019. The restricted cubic spline function was used to assess the dose-response relationship between sleep duration and ADL disability, and the odds ratios (ORs) of the associations were estimated by logistic regression models.

Results

The overall prevalence of ADL disability was 63% (64% in females and 58% in males). The prevalence was 71% in the Han population (72% in females and 68% in males), 60% in the Zhuang population (62% in females and 54% in males) and 53% in other ethnic population (53% in females and 53% in males). A nonlinear relationship between sleep duration and ADL disability was observed. Sleep duration of 8-10 hours was associated with the lowest risk of ADL disability. Sleep duration (≥12 hours) was associated with the risk of ADL disability among the oldest-old individuals after adjusting for confounding factors (OR = 1.47, 95% CI [1.02, 2.10], p < 0.05).

Conclusion

Sleep duration more than 12 hours may be associated with an increased risk of ADL disability in the oldest-old individuals, and the optimal sleep duration among this population could be 8-10 h.

From degenerative disease to malignant tumors: Insight to the function of ApoE

Apolipoprotein E (ApoE) is a multifunctional protein involved in lipid transport and lipoprotein metabolism, mediating lipid distribution/redistribution in tissues and cells. It can also regulate inflammation and immune function, maintain cytoskeleton stability, and improve neural tissue Function. Due to genetic polymorphisms of ApoE (ε2, ε3, and ε4), its three common structural isoforms (ApoE2, ApoE3, ApoE4) are also associated with the risk of many diseases, especially degenerative diseases, such as vascular degenerative diseases including atherosclerosis (AS), coronary heart disease (CHD), and neurodegenerative disease like Alzheimer's disease (AD). The frequency of the ε4 allele and APOE variants were significantly higher than that of the ε2 and ε3 alleles in the patients with CHD or AD. In recent years, ApoE has frequently appeared in tumor research and become a tumor biomarker gradually. It has been found that ApoE is highly expressed in most solid tumor tissues, such as glioblastoma, gastric cancer, pancreatic ductal cell carcinoma, etc. Studies illustrated that ApoE could regulate the polarization changes of macrophages, participate in the construction of tumor immune microenvironment, regulate tumor inflammation and immune response and play a role in tumor progression, invasion, and metastasis. Of course, many functions of ApoE and its relationship with diseases are still under research. By reviewing the structure and function of ApoE from degeneration diseases to tumor neoplasms, we hope to better understand such a biomarker and further explore the value of ApoE in later studies.

Association of Apolipoprotein E Gene Polymorphism with Ischemic Stroke in Coronary Heart Disease Patients Treated with Medium-intensity Statins

OBJECTIVE

To study the association of apolipoprotein E(APOE) gene polymorphism with ischemic stroke (IS) in coronary heart disease (CHD) patients treated with medium-intensity statins.

METHODS

The retrospective study was performed on 662 samples including 169 CHD subjects complicated with IS, 296 subjects with CHD, and 197 control subjects. The APOE gene was obtained from case files. Univariable and multivariable logistic regression analyses were utilized to recognize the possible risks of CHD and IS.

RESULTS

The frequency of ε3-ε4 genotype was increased in the CHD group (p=0.013) and CHD-IS group (p=0.001), the frequency of ε4 allele was also increased in the CHD group (p=0.047) and the CHD-IS group (p=0.009) compared with control group. ε3-ε4 genotype was the independent risk for CHD and CHD-IS after adjusting for traditional risk factors with adjusted odds ratio (AOR) 2.210, 95%CI: 1.263-3.867, p=0.005) and (AOR 2.794, 95%CI: 1.539-5.072, p=0.002). The ε4 allele was also significantly associated with CHD (AOR 2.126, 95%CI: 1.265-3.575,=0.004) and CHD-IS (AOR 2.740, 95%CI: 1.569-4.784, p=0.001).

CONCLUSION

These results demonstrated that ε4 allele influenced the development of CHD with or without IS, especially for the genotype of ε3-ε4. CHD patients carrying the ε3-ε4 genotype and the ε4 allele were significantly associated with the incidence of IS, even if medium-intensity statins had been used.

Association of APOE Gene Polymorphisms with Cerebral Infarction in the Chinese Population

Background

Apolipoprotein E (ApoE) is a multifunctional protein that plays an important role in lipoprotein metabolism. However, the relationship between APOE gene polymorphisms and cerebral infarction in the Chinese population remains unclear. Therefore, we studied the role of APOE gene polymorphisms in patients with cerebral infarction in a Chinese population.

Material/Methods

This study involved 906 patients with cerebral infarction and 1,141 individuals without cerebral infarction who served as controls. APOE genotypes were identified in all participants who participated in the study. Factors influencing cerebral infarction were also analyzed.

Results

Statistically significant variances in the distribution and frequencies of the APOE genotypes in the patients were observed (ɛ2/ɛ3 versus ɛ2/ɛ4 versus ɛ3/ɛ3=22.85% versus 7.62% versus 56.95%) and controls (ɛ2/ɛ3 versus ɛ2/ɛ4 versus ɛ3/ɛ3=17.27% versus 2.72% versus 66.87%; p<0.001). Univariate analysis showed that the APOE ɛ3/ɛ3 genotype [OR, 0.393 (95% CI, 0.237–0.653); p<0.001] and ɛ3/ɛ4 genotype [OR, 0.376 (95% CI 0.221–0.637); p<0.001] played a protective role against cerebral infarction in Chinese men.

Conclusions

Statistically significant variances in the distribution and frequencies of the APOE genotypes of the patients and controls were observed. The study demonstrated that the APOE ɛ3/ɛ3 and ɛ3/ɛ4 genotypes played a protective role against cerebral infarction in Chinese men, but not women. Additionally, the ɛ2/ɛ4 genotype may be a potential risk factor in men, whereas ɛ3/ɛ4 genotype may play a potential protective role against this disease in women.

Apolipoprotein E Gene Polymorphisms in Saudi Patients with Systemic Lupus Erythematosus

Apolipoprotein E (APOE) is a glycosylated protein with multiple biological properties. APOE gene polymorphism plays a central role in lipid metabolism and has recently been suggested to regulate inflammation. Our objective is to evaluate whether APOE polymorphism affects susceptibility to SLE. APOE genotyping was performed using ApoE StripAssay™ kit. Results indicated significantly higher frequencies of allele ε4 and genotype ε3/ε4 and lower frequencies of allele ε3 and genotype ε3/ε3 in SLE patients than controls. APOE ε2 allele was found in three patients, whereas it was absent in controls. The frequencies of allele ε4 and genotype ε3/ε4 were significantly higher in SLE patients with renal involvement and those of alleles ε2, ε4 and genotypes ε2/ε3, ε3/ε4 were higher in patients with neuropsychiatric symptoms. It is concluded that APOE allele ε4 is associated with susceptibility risk/clinical manifestations of SLE and ε2 may increase its severity while ε3 is protective for SLE in Saudis.

Association between APOE ε4 Genotype and Memory Impairment in Elderly with Normal Global Cognitive Assessment

Aim: Early prediction using cognitive evaluation tools that are less influenced by education level is beneficial for dementia screening. This study investigated the relationship between Word List Memory Immediate Recall (WLM IR) and the Saving Score (SS) with having the APOE ε4 risk allele in the elderly with normal global cognitive assessment. Methods: A cross-sectional study on 105 subjects ≥60 years with normal MMSE scores who met inclusion criteria. Memory impairment (MI) if: WLM IR score on the third trial <8 or an SS score <80%. Results: The majority of the subjects were female (68.6%), 65 ± 7.1 years, had undertaken formal education for <6 years (56.2%), had MI (81%), and the APOE ε4 genotype was detected in 24.8% of subjects. There was a significant relationship between APOE ε4 and lower WLMIR (p = 0.02, OR 7.92, CI 95% (1.00–62.38)). Conclusions: WLM IR score is lower in elderly people with the APOE ε4 despite their normal global cognitive assessment results, and these scores were not influenced by education level. Further research needs to confirm that the WLM IR can be used to screen for early dementia.

Apolipoprotein E polymorphism is associated with susceptibility to schizophrenia among Saudis

INTRODUCTION

Apolipoprotein E (APOE) genotypes influence the phenotype of several neurodegenerative disorders including Alzheimer's and Parkinson disease and may affect schizophrenia pathogenesis. This study was undertaken to determine the association between APOE gene polymorphisms and schizophrenia in the Saudi population.

MATERIAL AND METHODS

APOE allele and genotype frequencies were studied in 380 Saudi subjects including schizophrenia patients and matched controls using polymerase chain reaction (PCR) and reverse-hybridization techniques.

RESULTS

The frequencies of the APOE allele ε2 and genotypes ε2/ε3 and ε2/ε4 were significantly higher in the schizophrenia patients as compared to controls, suggesting that the ε2 allele and its heterozygous genotypes may increase the susceptibility to schizophrenia. In contrast, the frequencies of the ε3 allele and ε3/ε3 genotype were lower in patients as compared to controls, suggesting a protective effect of APOE ε3 for schizophrenia. This study indicated that APOE ε4 was differentially associated with schizophrenia depending on the symptoms as the frequency of the ε4 allele was significantly higher in schizophrenia patients with positive symptoms. By contrast, no significant association between APOE ε4 and schizophrenia patients with negative symptoms was observed. Genotypes ε2/ε2 and ε4/ε4 were absent in patients and controls. Moreover, the age of onset was significantly lower in patients with the APOE ε2/ε3 genotype. There was no significant difference in the frequencies of APOE alleles and genotypes between male and female schizophrenia patients.

CONCLUSIONS

The results of this study clearly show that APOE alleles and genotypes are associated with risk of developing schizophrenia and early age of onset in Saudis.

Genetic association of apolipoprotein E polymorphisms with inflammatory bowel disease

AIM: To study the association of apolipoprotein E (APOE) polymorphisms with the susceptibility of inflammatory bowel disease (IBD) in Saudi patients.

METHODS: APOE genotyping was performed to evaluate the allele and genotype frequencies in 378 Saudi subjects including IBD patients with ulcerative colitis (n = 84) or Crohn’s disease (n = 94) and matched controls (n = 200) using polymerase chain reaction and reverse-hybridization techniques.

RESULTS: The frequencies of the APOE ε2 allele and ε2/ε3 and ε2/ε4 genotypes were significantly higher in IBD patients than in controls (P < 0.05), suggesting that the ε2 allele and its heterozygous genotypes may increase the susceptibility to IBD. On the contrary, the frequencies of the ε3 allele and ε3/ε3 genotype were lower in IBD patients as compared to controls, suggesting a protective effect of APOE ε3 for IBD. The prevalence of the ε4 allele was also higher in the patient group compared to controls, suggesting that the ε4 allele may also increase the risk of IBD. Our results also indicated that the APOE ε4 allele was associated with an early age of IBD onset. No effect of gender or type of IBD (familial or sporadic) on the frequency distribution of APOE alleles and genotypes was noticed in this study.

CONCLUSION: APOE polymorphism is associated with risk of developing IBD and early age of onset in Saudi patients, though further studies with a large-size population are warranted.

The Association between Apolipoprotein E Gene Polymorphism and Mild Cognitive Impairment among Different Ethnic Minority Groups in China

The association, in different ethnic groups, of apolipoprotein E (apoE) gene polymorphism with mild cognitive impairment (MCI) has been unclear. Few studies have examined the association in Chinese minorities. The current study explores the association between apoE gene polymorphism and MCI in one of the biggest ethnic groups—the Hui—and compares it with the Han. The Minimental State Exam, Activities of Daily Living Scale, and Geriatric Depression Scale were administered to 306 ethnic Hui and 618 ethnic Han people aged ≥55 years. ApoE genotypes were determined using the high resolution melting curve method. The distribution of the apoE genotype and the frequency of alleles ε2, ε3, and ε4 were similar in the Hui and Han groups. In analyses adjusted for age, gender, and education level, the ε4 allele was a risk factor for MCI in both the Hui group (OR = 2.61, 95% CI: 1.02–6.66) and the Han group (OR = 2.36, 95% CI: 1.19–4.67), but the apoE ε2 allele was protective for MCI only in the Han group (OR = 0.48, 95% CI: 0.38–0.88). The association of some apoE genotypes with MCI may differ in different ethnic groups in China. Further studies are needed to explore this effect among different populations.

Apoliprotein E genotype is associated with apoliprotein B plasma levels but not with coronary calcium score in very elderly individuals in primary care setting

BACKGROUND

Epidemiological surveys indicate the influence of polymorphisms of apolipoprotein (apo) E on plasma lipids and triglyceride-rich lipoprotein levels, with impact on atherosclerotic phenotypes.

AIM

We studied the association of classic genotypes of the apoE gene with clinical and biochemical risk factors for atherosclerosis in a segment of the very-old Brazilian individuals, with emphasis on the lipemic profile.

METHODS

We performed cross-sectional analyses of clinical and laboratory assessments, including cardiac computed tomography, across ε2, ε3 and ε4 carriers of the apoE gene with a convenience sample of 208 participants eligible for prevention against cardiovascular events.

RESULTS

When non-ε4 carriers were compared with ε4 carrying subjects, lower levels of ApoB as well as ApoB/ApoA ratios were observed in the former group. Tests between apoE polymorphisms with other clinical/biochemical variables and those with arterial calcification showed no significant differences between groups.

CONCLUSION

The study suggests a possible atherogenic role of the ε4 allele attributable to increased ApoB levels and ApoB/ApoA ratios among very-old subjects in primary care setting.

Variable frequencies of apolipoprotein E genotypes and its effect on serum lipids in the Guangxi Zhuang and Han children

Guangxi Zhuang, the largest ethnic minority in China, is located in the southern part of the country, and well-known to the world as the longevity village. Studies of apolipoprotein E (APOE) polymorphism in adults suggest the lower frequencies of E4 allele and E4/E4 genotype may account, in part, for the favorable lipid profiles of Guangxi Zhuang. However, the effect of APOE polymorphism on serum lipids in the Guangxi Zhuang children is yet unknown to date. In the present study, genomic DNA was extracted from 278 Guangxi Zhuang and 200 Guangxi Han children. APOE genotypes were determined by PCR-restriction fragment length polymorphism (RFLP) analysis. The fasting serum lipoprotein a [Lp(a)], total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (apoA1) and apoB were measured. Our results demonstrated that no significant differences in serum lipids were observed between the Guangxi Zhuang and Han children. The E4/E4 and E4/E3 genotypic frequencies were significantly lower in the Guangxi Zhuang children compared with the Guangxi Han children, whereas for E2/E2, E3/E2 and E4/E2 genotypic frequencies the opposite was presented. Though no significant differences in serum lipid concentrations were found for variant alleles both in the Guangxi Zhuang and Han children, the trend was observed in the association of higher levels of Lp(a), TC, TG and LDL-C with E4 allele in the Guangxi Zhuang children. In conclusion, a significant heterogeneity in APOE genetic variation indeed exists between the Guangxi Zhuang and Han ethnic group. The E4 allele may serve as a genetic marker for susceptibility to higher lipid profiles in the Guangxi Zhuang children. Lifestyle should be modified, according to APOE polymorphism even in the young children.

Genetic variants at the APOE, lipoprotein lipase (LpL), cholesteryl ester transfer protein (CETP), and endothelial nitric oxide (eNOS) genes and coronary artery disease (CAD): CETP Taq1 B2B2 associates with lower risk of CAD in Asian Indians

Coronary artery disease (CAD) arises due to a complex interplay between the environment and genetic factors. Alterations in many of the biomarkers such as lipids and lipoprotein levels are characteristic of CAD. The phenotypes themselves have genetic determinants, and many single-nucleotide polymorphisms (SNPs) have been identified which influence them. The current study aims to evaluate the effect of six common polymorphisms at four loci, lipoprotein lipase (D9N, N291S, S447X), apolipoprotein E (APOE), cholesteryl ester transfer protein (C277T), and endothelial nitric oxide synthase (E298D), on lipid and lipoprotein levels and its association with CAD. Genotyping for the SNPs was done in 240 Indians of which 90 had proven CAD. The other 150 were clinically free from CAD and acted as controls. Relation of genetic variants, clinical history, and biochemical parameters with CAD were analyzed by multiple regression analysis. The frequency of the B2 allele in the CETP gene was significantly lower in cases than in controls (0.40 vs 0.49, P = 0.042). Significant association of CETP Taq1B SNP was seen with total cholesterol and low density lipoprotein cholesterol. Multivariate analysis accounting for clinical and metabolic predictors of CAD showed smoking to be a significant risk factor (odds ratio (OR) 4.347, 95% confidence interval (CI) 1.888-10.012, P = 0.001) and the CETP B2 variant imparting atheroprotection (OR 0.312, 95% CI 0.116-0.841, P = 0.021) possibly through a favorable lipid profile. None of the other SNPs were associated with the risk of CAD.