Preliminary evidence for a role of apolipoprotein E alleles in identifying haemodialysis patients at high vascular risk

Detection of Apolipoprotein E Gene Polymorphism and Blood Lipid Level in Hemodialysis Patients

Background

The aim was to investigate the clinical characteristics of lipid metabolism and the effect of apolipoprotein E (ApoE) gene polymorphism on lipid metabolism in hemodialysis patients.

Methods

The serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), ApoA1, ApoB, ApoE and lipoprotein Lp(a) were detected by polymerase chain reaction-restriction fragment length (PCR-RFLP).

Results

The level of serum TG was significantly increased and the level of HDLC was significantly decreased in hemodialysis patients. Serum TG level was 33% higher than normal, and HDLC was 10.4% less than normal. The correlation analysis showed that TG level was significantly correlated with serum albumin level and extracorporeal circulation blood flow during dialysis. HDLC was significantly correlated with KT/V. The incidence of hypertension in hemodialysis patients was 73.6% and cardiovascular disease was 25%. The level of TG in the cardiovascular disease group was significantly higher than that in the non-cardiovascular disease group, and there was no significant difference between the hypertensive group and the non-hypertensive group. ApoE gene polymorphism test showed that the frequency of ApoE genotype ε3/3 and allele ε3 was the highest in hemodialysis patients, and the levels of TC, TG and LDLC were higher in ApoE genotype ε3/4 + ε4/4.

Conclusion

The levels of serum TG and ApoB were significantly increased in patients with hemodialysis, and HDLC and other indexes were significantly decreased. The level of TG in patients with cardiovascular complications was significantly higher than in patients without complications. TG level was significantly correlated with serum albumin level and extracorporeal circulation blood flow during dialysis. HDLC was significantly correlated with KT/V. Hemodialysis patients who had ApoE allele ε4 are prone to lipid metabolism disorders.

The association between serum ApoE genetic polymorphism and serum lipid level in hemodialysis patients

Growing evidence indicates that apolipoprotein E (ApoE) is one of the most important candidate genes for influencing the development of hemodialysis (HD). This study aims to detect the potential association between serum ApoE genetic polymorphism and serum lipid level in HD. A total of 485 subjects were enrolled in this case-control study. The created restriction site polymerase chain reaction and DNA sequencing methods were used to investigate ApoE c.109G>A genetic polymorphism. Our data suggested that there were significant differences in the distribution of allelic and genotypic frequencies between HD patients and healthy controls. The levels of total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, ApoA-I, ApoB, ApoE, and lipoprotein (a) for genotype AA were different from genotype GG in HD patients and healthy controls. Our findings support that the ApoE c.109G>A genetic polymorphism might influence the development of HD and could be a risk factor for assessing HD.

The effects of serum apolipoprotein E genetic variants and concentration on serum lipid parameters in haemodialysis patients

Objectives

Many epidemiological studies demonstrate that the apolipoprotein E gene (ApoE) is an important candidate gene for playing key roles in the development of haemodialysis (HD). The purpose of this study is to evaluate the effects of ApoE genetic variants and concentration on serum lipid parameters in HD.

Methods

A total of 288 HD patients and 292 healthy controls were enrolled in this case–control study. The genotypes of ApoE genetic variants were investigated through the created restriction site-polymerase chain reaction and DNA-sequencing methods.

Key findings

Our data indicated that the levels of triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I (ApoA-I), ApoB, ApoE, lipoprotein (a) (Lp(a)) of mutant genotypes in ApoE c.61G > A and c.761T > A genetic variants were different from those subjects with wild genotype in HD patients and healthy controls.

Conclusions

These preliminary results from this study suggest that the ApoE genetic variants and concentration could affect the serum lipid parameters in HD and could be risk factors for evaluating HD.

Apolipoprotein E gene variants on the risk of end stage renal disease

Objective

End-stage renal disease (ESRD) is a severe health concern over the world. Associations between apolipoprotein E (apoE) gene polymorphisms and the risk of ESRD remained inconclusive. This study aimed to investigate the association between apoE gene polymorphisms and ESRD susceptibility.

Methods

Databases including PubMed, Embase, Web of Science and the Cochrane Library were searched to find relevant studies. Meta-analysis method was used synthesize the eligible studies.

Results

Sixteen pertinent case-control studies which included 3510 cases and 13924 controls were analyzed. A significant association was found between ε2 allele and the ESRD risk (odds ratio (OR) = 1.30, 95% confidence interval (CI) 1.15–1.46, P < 0.0001; I² = 18%, P for heterogeneity = 0.24). The ε2ε3, ε2ε4, ε3ε3, ε3ε4, ε4ε4, ε3 and ε4 were not associated with the susceptibility of ESRD. In the subgroup analysis by ethnicity, there was a statistically significant association between ε2ε3 or ε2 allele and ESRD risk in East Asians (OR = 1.66, 95% CI 1.31–2.10, P < 0.0001; OR = 1.62, 95% CI 1.31–2.01, P < 0.0001, respectively), but not in Caucasians. E2 carriers had higher plasma apoE (mean difference = 16.24 mg/L, 95% CI 7.76-24.73, P = 0.0002) than the (ε3 + ε4) carriers in patients with ESRD. The publication bias was not significant.

Conclusion

The ε2 allele of apoE gene might increase the risk of ESRD. E2 carriers expressed higher level of plasma apoE in patients with ESRD. More well-designed studies are needed to confirm these associations in the future.

Tumor Necrosis Factor-α Gene Polymorphism Correlates with Cardiovascular Disease in Patients with End-Stage Renal Disease

BACKGROUND AND OBJECTIVE

Tumor necrosis factor-alpha (TNFalpha) is a potent proinflammatory cytokine. Through its effects on lipid metabolism and endothelial function, TNFalpha is involved in cardiovascular disease (CVD). We have studied two polymorphisms in the promoter region of the TNFalpha gene (TNF -308G/A and TNF -238G/A) in end-stage renal disease (ESRD) patients with and without CVD. The aim was to assess the association of these polymorphisms with ESRD and cardiovascular comorbidity in hemodialyzed patients.

METHODS

A total of 603 patients with ESRD treated with hemodialysis (382 patients with CVD) and 325 healthy control subjects were genotyped for the TNF -308G/A and TNF -238G/A ploymorphisms by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) procedure.

RESULTS

The A allele of the TNF -308 polymorphism was more frequent in the ESRD group than in control individuals. The odds ratio (OR) for the risk allele was 2.05 (95% CI 1.48, 2.84). In the subgroup of ESRD patients with CVD, the OR was 5.76 (95% CI 3.67, 9.03) relative to ESRD patients without CVD. There was no association observed between the TNF -238 polymorphism and renal failure or CVD in ESRD patients.

CONCLUSION

Our results demonstrate for the first time that the A allele of the TNF -308 polymorphism is associated with CVD in hemodialyzed ESRD patients. If confirmed in prospective studies, it may be a predictor of increased susceptibility to CVD in these patients.

The effects of apoA-I/C-III/A-IV, apoE and apoB polymorphisms on carotid artery intima-media thickness

Different apolipoprotein combinations explain most of the functional differences between plasma lipoproteins. This emphasizes the pivotal role of apolipoproteins in the homeostasis and physiological control of lipid metabolism. Genetic polymorphisms of apolipoprotein (apo)A-I/C-III/A-IV, apoE and apoB have been suggested to modulate plasma lipid levels as well as the risk of coronary artery disease and stroke. Carotid artery intima-media thickness has been shown to represent preclinical atherosclerosis and has, therefore, been used as a surrogate in quantifying the early stages of atherosclerosis. The effects of the polymorphisms in apoA-I/C-III/A-IV and apoB on carotid intima-media thickness are poorly known. The corresponding influence of apoE polymorphisms has been studied more extensively, but the results are not yet conclusive. In this review, these results are presented in detail and the potential reasons and mechanisms for the discrepancies are discussed.

Association between apolipoprotein E genotype and carotid intima-media thickness may suggest a specific effect on large artery atherothrombotic stroke

BACKGROUND AND PURPOSE

Apolipoprotein E genotype (APOE) influences cholesterol levels and ischemic heart disease. Although there is no convincing overall association with ischemic stroke, APOE may influence large artery (atherothrombotic) stroke, for which carotid intima-media thickness (CIMT) is an informative intermediate phenotype. We therefore performed a systematic review and meta-analysis of the association between APOE and CIMT.

METHODS

We sought all published studies assessing the association between APOE and CIMT. From each study, we extracted available data on study methods, subjects' characteristics, and mean (and standard deviation) CIMT for each genotype or genotype group. We calculated study-specific and random effects pooled differences in mean CIMT between genotype groups, and assessed heterogeneity between studies and predefined subgroups using I(2) and chi(2) statistics.

RESULTS

Meta-analysis of 22 published studies (30,879 subjects) showed a significant association between APOE and CIMT (pooled mean difference epsilon 4- versus epsilon 2-allele containing genotypes 46 microm, 95% CI 29 to 62, P<0.00001). We found evidence of small study (mainly publication) bias, with a diminished (but still highly statistically significant) association in studies of >1000 subjects (pooled mean difference 17 microm, 95% CI 12 to 23, P<0.00001). The association was larger among high vascular risk and eastern Asian populations, but this may simply reflect the smaller size of these studies.

CONCLUSIONS

Our results show a clear association of APOE with CIMT, even though publication bias means that this is overestimated by the published literature. These findings suggest the possibility of a specific association with large artery ischemic stroke.

A common VLDLR polymorphism interacts with APOE genotype in the prediction of carotid artery disease risk

The genetic factors associated with carotid artery disease (CAAD) are not fully known. Because of its role in lipid metabolism, we hypothesized that common genetic variation in the very low density lipoprotein receptor (VLDLR) gene is associated with severe CAAD (>80% stenosis), body mass index (BMI), and lipid traits in humans. VLDLR was resequenced for variation discovery in 92 subjects, and single nucleotide polymorphisms (tagSNPs) were chosen for genotyping in a larger cohort (n = 1,027). Of the 17 tagSNPs genotyped, one tagSNP (SNP 1226; rs1454626) located in the 5' flanking region of VLDLR was associated with CAAD, BMI, and LDL-associated apolipoprotein B (apoB). We also identified receptor-ligand genetic interactions between VLDLR 1226 and APOE genotype for predicting CAAD case status. These findings may further our understanding of VLDLR function, its ligand APOE, and ultimately the pathogenesis of CAAD in the general population.

New Insight Into the Association of Apolipoprotein E Genetic Variants With Carotid Plaques and Intima-Media Thickness

BACKGROUND AND PURPOSE

Carotid plaques and elevated carotid artery intima-media thickness (IMT) are major predictors of vascular morbidity and mortality. Our aim was to test their association with 2 polymorphisms of the apolipoprotein E (apoE) gene, epsilon and -219G/T.

METHODS

The study was performed on 5856 subjects aged > or =65 years recruited from the French population for the Three-City Study. Carotid ultrasound examination included an assessment of atherosclerotic plaques in the extracranial carotid arteries and a measurement of IMT in the common carotid arteries (CCA) at a site free of plaques. The genetic association was tested using genotype and haplotype analyses.

RESULTS

In a multivariate analysis including both polymorphisms and vascular risk factors, carotid plaques were more frequent in epsilon4 homozygotes (adjusted odds ratio=2.12, 95% CI=1.27 to 3.53) and less frequent in epsilon2 carriers (adjusted odds ratio=0.79, 95% CI=0.66 to 0.95) compared with epsilon3 homozygotes. Adjusting for and stratifying on lipid levels did not modify these results. CCA-IMT was higher in carriers of the epsilon34 genotype (mean CCA-IMT=0.744 mm versus 0.732 mm for the epsilon33 genotype, P=0.002), but the association disappeared after excluding subjects with carotid plaques. No association was found between the -219 polymorphism and either carotid plaques or CCA-IMT, and there was no interaction or cis-effect between -219 and epsilon.

CONCLUSIONS

This study, conducted on a large population cohort of French elderly, demonstrated that carotid plaques were significantly associated with the apoE epsilon polymorphism independently of the -219 polymorphism and vascular risk factors, in particular lipid levels.

Phenotypic and genotypic risk factors for cardiovascular events in an incident dialysis cohort

Cardiovascular disease (CVD) remains the major cause of death in patients with end-stage renal disease (ESRD). Traditional risk factors do not explain the high prevalence of CVD in this population, and other non-traditional cardiovascular (CV) risk markers have now been described. Therefore, the potential relationship between CVD and phenotypic and genotypic risk markers was investigated prospectively in incident dialysis patients cohort. The 279 patients (244 on hemodialysis, 35 on peritoneal dialysis) within the Diamant Alpin Dialysis Cohort Study were investigated. Phenotypic and genotypic parameters were determined at dialysis initiation, patients monitored over a 2-year period, and CV events (morbidity and mortality) recorded. Globally, 82 CV events occurred and 26 patients (9.3%) died from CVD, whereas 28 (10%) died from non-CV causes. Previous CV events were strongly predictive of CV events occurrence, whatever patients had had one (hazard ratio (HR) 2, 95% confidence intervals (CI) 1.1-3.5) or more (HR 3.9, 95% CI 2.1-7.1) CV accidents before starting dialysis. Both lipoprotein(a) (HR 1.67, 95% CI 1-2.5) and total plasma homocysteine at cutoff 30 micromol/l (HR 1.7, 95% CI 1.1-2.8) were independent predictors of CV events outcome. In the subgroup of patients with homocysteine < 30 micromol/l, methylenetetrahydrofolate reductase (MTHFR) TT was the sole biological parameter predictive of CV event outcome (HR 2.5, 95% CI 1.1-10, P = 0.03). ESRD patients who enter chronic dialysis with a previous CV event, high total homocysteinemia levels, or MTHFR 677TT genotype must be considered at high risk of incident CV events.

Genetics of Ultrasonographic Carotid Atherosclerosis

The search for genes related to the cause of common complex disorders such as cardiovascular disease has been frustrating, partly because of the many factors known to contribute to cardiovascular disease and the potential "distance" of cardiovascular disease as a phenotype from genes and gene products. Linkage and association studies for phenotypes more proximal in the pathway from DNA sequence variation to overt clinical disease, such as ultrasound-defined carotid atherosclerosis, may potentially be more enlightening. Only one genetic variant previously reported to be associated with atherosclerosis or clinically evident cardiovascular disease, matrix metalloproteinase (MMP) 3, has shown consistently positive associations with carotid disease, although it has not been studied widely. Another, PON1 L55M, is weakly associated in subgroups only, and 2, ApoE and MTHFR, are equivocal. Genetic variants reported to be associated with clinical cardiovascular disease show weak or no relationship to carotid atherosclerosis. This may reflect the known inconsistency in associations of genetic variants with clinical cardiovascular disease itself. Alternatively, genetic determinants of ultrasound-defined carotid atherosclerosis may differ from those of clinically manifest cardiovascular disease and may require pursuit through large-scale genomic studies of carotid atherosclerosis as a distinct phenotype. Only 1 genetic variant, MMP 3, has shown consistently positive associations with ultrasonographic carotid disease, although it has not been studied widely. Another, PON1 L55 mol/L, is weakly associated in subgroups only. Genetic variants reported to be associated with clinical cardiovascular disease show weak or no relationship to carotid atherosclerosis.

The influence of serum apolipoprotein E concentration and polymorphism on serum lipid parameters in hemodialysis patients

BACKGROUND

Apolipoprotein E (ApoE) polymorphism has been shown to influence serum lipid parameters and ApoE levels in both healthy subjects and hemodialysis (HD) patients. Conversely, ApoE concentration significantly affects serum lipid levels in the general population, independently of ApoE polymorphism, by modulating lipoprotein production, lipolytic conversion, and receptor-mediated clearance. Therefore, studying the effect of ApoE polymorphism on serum lipid levels without taking into account ApoE levels could lead to confounding results. However, such a combined study has not been performed in HD patients to date.

METHODS

Three hundred one patients without diabetes on long-term maintenance HD therapy and 200 matched healthy subjects were studied. Determination of levels of fasting serum ApoE and other lipid parameters, as well as common ApoE genotypes, was performed in all subjects.

RESULTS

HD patients had a significantly lower prevalence of the epsilon4 allele and greater levels of ApoE compared with the control population. ApoE2 allele carriers had significantly lower levels of ApoB and serum total, low-density lipoprotein, and non-high-density lipoprotein cholesterol, as well as increased ApoE levels. When ApoE levels were included in analysis, ApoE levels themselves were proven to be important determinants of serum lipid levels, whereas the effect of ApoE polymorphism became more pronounced. The combination of these 2 factors explains a much greater percentage of the variation in the studied parameters than each factor alone.

CONCLUSION

For the first time, our study provides data to support that ApoE concentration in combination with the ApoE polymorphism significantly influences serum lipid parameters in HD patients.

Apolipoprotein E and renal disease

Apolipoprotein E (ApoE) is a major constituent of plasma lipoproteins with many biological actions of great significance. Beyond the known influence of ApoE polymorphisms on serum lipid profile, the pathogenesis of atherosclerosis, and the development of neurodegenerative disorders, ApoE also has a major role in the pathogenesis and progression of a variety of renal diseases, as well as in the atherosclerotic complications associated with them. Briefly, the polymorphisms of ApoE are major determinants of plasma lipid levels in uremic patients. They may affect the risk for cardiovascular disease in this population, predispose to the development of diabetic nephropathy, influence the severity of certain glomerulopathies, and regulate mesangial and glomerular functions locally in the kidney microenvironment. Finally, certain mutations of the ApoE gene are associated with a recently described nephropathy, termed lipoprotein glomerulopathy.

The role of cardiovascular risk factors in Alzheimer's disease

The distinction between Alzheimer's disease and vascular dementia, the two most common types of dementia, has been undermined by recent advances in epidemiologic, clinical, imaging, and neuropathological studies. Cardiovascular risk factors, traditionally regarded as distinguishing criteria between the two entities, have been shown to be associated with both AD and vascular dementia. In this article, we propose mechanisms of action of cardiovascular risk factors in AD, suggest possible explanations for the overlap with vascular dementia and discuss the implications this might have on future differential diagnosis, research, and treatment strategies.

Atherosclerosis in patients with end-stage renal failure prior to initiation of hemodialysis

BACKGROUND

In dialysis patients cardiovascular mortality is 10 to 20 times higher than in general population. It remains uncertain whether atherosclerosis of dialysis patients is effectively accelerated because many of dialysis patients have more or less marked vascular lesions already at the start of dialysis treatment. SUBJECTS AND METHODS. Using B-mode ultrasonography (ATL HDI 3000), we compared intima-media thickness (IMT) and plaque occurrence (indicators of atherosclerosis) in the common carotid arteries (CC), in the area of bifurcation (CB) and in the proximal part of internal carotid arteries (CI) in 28 hemodialysis patients (14 men and 14 women; mean age 49.4 years; mean duration of HD treatment 66.6 months) with that in 28 age-sex matched patients prior to initiation of hemodialysis. We also investigated possible differences in atherosclerotic risk factors in both groups.

RESULTS

The IMT values of CC (0.71 vs. 0.70 mm; p = 0.937), CB (0.81 vs. 0.77 mm; p = 0,423) and CI (0.72 vs. 0.71 mm; p = 0.935) were not significantly different in dialysis patients and patients starting dialysis treatment. We also found no difference in plaque occurrence (61% vs. 54%; p = 0.787) and in atherosclerotic risk factors (hypertension, smoking, lipids) between both groups.

CONCLUSIONS

In our study we found no difference in atherosclerotic lesions in carotid arteries between dialysis patients and patients with end-stage renal failure starting dialysis treatment. Patients with chronic renal failure are at high risk for cardiovascular diseases so we should intervene earlier and more actively long before dialysis treatment in order to reduce the atherosclerotic risk factors.

Influence of apolipoprotein E, smoking, and alcohol intake on carotid atherosclerosis: National Heart, Lung, and Blood Institute Family Heart Study

BACKGROUND AND PURPOSE

Apolipoprotein E (apoE) isoforms and lifestyle factors play an important role in the development of coronary heart disease. The association of apoE and carotid atherosclerosis remains controversial.

METHODS

We investigated the relation of apoE, cigarette smoking, alcohol drinking, and their interaction with carotid atherosclerosis on 544 individuals free of coronary heart disease in the National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study. Atherosclerotic lesions of the carotid arteries were detected through high-resolution ultrasound.

RESULTS

Subjects in the apoE4 group had lower blood pressure, lower high-density lipoprotein cholesterol, and higher low-density lipoprotein cholesterol. In a multivariate logistic regression model, apoE isoforms and alcohol consumption were not significantly associated with the prevalence odds of carotid atherosclerosis (P=0.94 and 0.98, respectively, for trend). In contrast, compared with those who never smoked, the prevalence odds ratios for carotid atherosclerosis were 1.7 [95% confidence interval (CI),1.1 to 2.7], 2.8 (95% CI, 1.2 to 6.2), and 1.9 (95% CI, 0.7 to 5.5) for former smokers, current smokers of 1 to 20 cigarettes per day, and current smokers of >20 cigarettes day, respectively (P=0.0018 for trend). We did not find evidence of an interaction between apoE and alcohol consumption. Our data suggested a synergistic effect between the apoE allele epsilon(4) and smoking on carotid atherosclerosis: odds ratios were 1.7 (95% CI, 0.8 to 3.6) for smoking alone, 1.0 (95% CI, 0.6 to 1.8) for epsilon4 alone, and 3.7 (95% CI, 1.1 to 3.6) for the joint presence of the apoE allele epsilon4 and smoking.

CONCLUSIONS

Smoking but not alcohol consumption or ApoE is associated with an increased odds of carotid atherosclerosis. Our data suggest a synergistic effect between the apoE allele epsilon4 and smoking on carotid atherosclerosis.

Atherosclerosis risk is higher in continuous ambulatory peritoneal dialysis patients than in hemodialysis patients

While it has been reported that myocardial infarction and cerebrovascular disease are more common in continuous ambulatory peritoneal dialysis (CAPD) patients than in hemodialysis patients, some studies have not supported these results. The aim of this study was to compare CAPD and hemodialysis patients with regard to atherosclerotic changes and to assess which factors might be responsible for atherosclerosis in dialysis patients. Group 1 consisted of 65 CAPD patients, and Group 2 consisted of 109 hemodialysis patients who were age-, gender-, and duration-of-dialysis-matched with CAPD patients. We used ultrasonographic measurement of carotid artery intima media thickness to identify atherosclerosis. Known risk factors for atherosclerosis including hypertension, smoking, serum levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, lipoprotein (a) [Lp(a)], albumin, intact parathormone, fibrinogen, and C-reactive protein were determined in all patients. More atherosclerotic changes were seen in CAPD than in hemodialysis patients. Of all the atherosclerosis risk factors, only serum total cholesterol, LDL-C, and Lp(a) levels were significantly higher in patients on CAPD.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Effect of apolipoprotein E polymorphism on serum lipid, lipoproteins, and atherosclerosis in hemodialysis patients

Atherosclerosis and cardiovascular disease are the main causes of death in hemodialysis patients. Possession of the apolipoprotein E4 (ApoE4) allele has been associated with increased levels of serum lipids and with coronary and carotid artery atherosclerosis. We investigated the possible relationship between ApoE polymorphism and atherosclerosis risk factors in hemodialysis patients. Two hundred sixty-nine hemodialysis patients (115 women, 154 men) were included in our study. The mean patient age and mean hemodialysis duration were 45.8 +/- 15.3 years and 52.6 +/- 40.6 months, respectively. Testing was done on all patients to determine ApoE genotype and serum levels of total cholesterol (T-Cho), low-density lipoprotein (LDL-C), high-density cholesterol (HDL-C), triglyceride (TG), lipoprotein (a) (Lp[a]), intact parathormone (iPTH), and fibrinogen. ApoE genotype was identified with the polymerase chain reaction. Ultrasonographic measurement of carotid artery intima media thickness (IMT) was used to diagnose atherosclerosis. We also analyzed ApoE polymorphism and risk factors such as age, gender, duration of hemodialysis, smoking, and hypertension in relation to the presence of atherosclerosis. Serum T-Cho and LDL-C levels were higher in patients with the ApoE4/3 phenotype than in those with ApoE3/3 and ApoE3/2 phenotypes (P < 0.05). However, there was no statistically significant link between ApoE polymorphism and serum levels of TG, HDL-C, or Lp(a) (P > 0.05). Apart from a relationship with age and duration of hemodialysis (P < 0.05), we found no significant association between atherosclerosis and ApoE polymorphism or the other risk factors analyzed (P > 0.05). In conclusion, although ApoE polymorphism significantly affects serum levels of T-Cho and LDL-C in hemodialysis patients, this study indicates that ApoE polymorphism is not associated with the presence of atherosclerosis in these individuals. The high incidence of atherosclerosis in these patients underlines the need for further research on other possible causative factors.