Erkki Ilveskoski

Age-Dependent Association of Apolipoprotein E Genotype With Coronary and Aortic Atherosclerosis in Middle-Aged Men An Autopsy Study

BACKGROUND Apolipoprotein E (apoE) polymorphism is one of the genetic determinants of serum cholesterol values. The apoE epsilon4 allele has been associated with advanced coronary heart disease (CHD) diagnosed by angiography, but the role of the apoE genotype in atherosclerosis has not been confirmed at vessel-wall level, nor is any age-dependent effect of the apoE genotype on the development of CHD known. METHODS AND RESULTS The right and left anterior descending coronary arteries (RCA and LAD) and the aorta from 700 male autopsy cases (Helsinki Sudden Death Study) in 1981-1982 and 1991-1992 (average age 53 years, range 33 to 70 years) were stained for fat, and all areas covered with fatty streaks, fibrotic plaques, and complicated lesions were measured. In the RCA and LAD, the apoE genotype was significantly associated with the area of total atherosclerotic lesions in men <53 years old but not with that in older men (P=0.0085 and P=0.041, respectively, for age-by-genotype interaction). Men <53 years old with the epsilon4/3 genotype showed 61% larger total atherosclerotic lesion area in the RCA (P=0.0027) and 26% larger area in the LAD (P=0.12) than did men with the epsilon3/3. The apoE epsilon4/3 was also associated with atherosclerotic lesions in the abdominal (P=0.014) and thoracic (P=0.12) aorta, but this effect, unlike that of the coronary arteries, was not age-related. CONCLUSIONS In men, the apoE epsilon4 allele is a significant genetic risk factor for coronary atherosclerosis in early middle age. This suggests that at older age, other known risk factors of CHD play a more important role in the atherosclerotic process than apoE polymorphisms.

Polymorphisms within the tumor necrosis factor locus and prevalence of coronary artery disease in middle-aged men

Tumor necrosis factor (TNF) is an important cytokine in the inflammation process of atherosclerosis and is also involved in lipid metabolism. Two biallelic polymorphisms within TNF gene locus-TNFA at the position -308 in the promoter region of the TNF gene and TNFB in the first intron of the lymphotoxin-alpha (LT-alpha) have been reported to be associated with TNF production and with susceptibility to inflammatory diseases. We studied the association of these polymorphisms within the major histocompatibility complex (MHC) III region with coronary atherosclerosis and its manifestations. The autopsy series comprised 700 Caucasian Finnish men, aged 33-70 years (The Helsinki Sudden Death Study). Coronary stenosis and surface area of atherosclerotic changes (fatty streaks, fibrous plaques, complicated lesions and calcification) were measured and the presence of myocardial infarction and coronary thrombosis recorded. TNFA and TNFB genotypes were determined by the PCR-RFLP technique. The allele frequencies were TNFA1/TNFA2=0.88/0.12 and TNFB1/TNFB2=0.30/0.70. There was a strong linkage disequilibrium between the two polymorphisms. There were no differences in coronary stenosis and in the frequency of old or recent myocardial infarction or coronary thrombosis between men with different genotype status in either locus. Men with TNFA22 or TNFB11 genotype tended to have more fibrous lesions and calcification in their coronary arteries. TNFA and TNFB polymorphisms are unlikely to contribute to progression of atherosclerosis in a way clinically important.

Fibrinogen Gene Promoter −455 A Allele as a Risk Factor for Lacunar Stroke

Background and Purpose— Elevated fibrinogen levels are suggested to increase the risk of myocardial infarction and stroke. Carriers of the A allele of the fibrinogen −455G/A polymorphism have increased plasma fibrinogen levels. We studied the association of this polymorphism with stroke subtype in the Stroke Aging Memory (SAM) cohort. Methods— The SAM cohort comprises 486 consecutive patients 55 to 85 years of age who, 3 months after ischemic stroke, completed a detailed stroke assessment. Stroke subtypes were examined with MRI. −455G/A genotype was determined by polymerase chain reaction. MRI and genotype data were available for the 299 patients who constitute the present study population. Results— Genotype distributions were 64.9% (GG), 31.8% (GA), and 3.3% (AA). In a logistic regression model with age, sex, hypertension, diabetes, hypercholesterolemia, hypertriglyceridemia, myocardial infarction, arrhythmia, atrial fibrillation, peripheral arterial disease, and smoking as possible confounders, there was a significant association between A+ genotype and ≥3 lacunar infarcts (odds ratio [OR], 2.57; 95% CI, 1.23 to 5.36;P =0.01). Hypertensive patients carrying the A allele had increased risk (OR, 4.24; 95% CI, 1.29 to 13.99;P =0.02) for ≥3 lacunar infarcts. A similar increase in risk was observed among smokers with the A+ genotype (OR, 2.67; 95% CI, 0.92 to 7.77;P =0.07). Conclusions— Stroke patients carrying the A allele of the B&bgr;-fibrinogen −455G/A polymorphism frequently presented with multiple lacunar infarcts. This association was stronger among hypertensives and smokers. These associations suggest that the A allele may predispose to atherothrombotic events in cerebrovascular circulation.

Association of Apolipoprotein E Polymorphism With Outcome After Aneurysmal Subarachnoid Hemorrhage A Preliminary Study

Background and Purpose Variation in the outcome after aneurysmal subarachnoid hemorrhage (SAH) is not fully explained by known prognostic factors. APOE genotype is the most important genetic determinant of susceptibility to Alzheimer’s disease, and it is also shown to be associated with the outcome after traumatic brain injury. We studied the association of apolipoprotein E polymorphism with the outcome after aneurysmal SAH. Methods A total of 160 consecutive patients were admitted after SAH to a neurosurgical unit. The clinical assessment after the SAH was performed with the Hunt and Hess grading scale. The severity of the bleeding as visualized on CT was assessed by Fisher’s grading system. Outcome was assessed with the Glasgow Outcome Scale. APOE genotypes were determined by polymerase chain reaction–restriction fragment length polymorphism. Results 126 patients had aneurysmatic SAH, and detailed information on outcome and APOE genotype was available for 108 patients (86%). Sixteen (40%) of 40 patients with APOE &egr;4 had an unfavorable outcome compared with 13 (19%) of 68 without the APOE &egr;4 allele (OR 2.8, 95% CI 1.18 to 6.77). Association was more significant after adjustment for age, rebleeding, clinical status on admission, and CT scan findings (OR 7.1, 95% CI 1.9 to 26.3;P =0.0035). Conclusions Our findings show a significant genetic association of APOE polymorphism with outcome after spontaneous aneurysmal SAH. Genetic factors thus seem to explain a part of individual differences in the recovery of SAH.

Neuropeptide Y and Alcoholism: Genetic, Molecular, and Pharmacological Evidence

This article presents the proceedings of a symposium presented at the combined meeting of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism, held in San Francisco, CA, in June 2002. The organizers and chairpersons were Subhash C. Pandey and Todd E. Thiele. The presentations were (1) Altered ethanol-induced sedation and ethanol drinking in mutant mice lacking specific NPY receptor, by Todd E. Thiele; (2) NPY in P and NP rats: polymorphism and mRNA expression, by Lucinda G. Carr; (3) The cAMP-dependent PKA in the central amygdala regulates alcohol intake through NPY gene, by Subhash C. Pandey; (4) Involvement of NPY in alcohol dependence: from animal models to human genetics, by Markus Heilig; and (5) Association of neuropeptide Y polymorphism with the occurrence of type 1 and type 2 alcoholism, by Erkki Ilveskoski.

Apolipoprotein E polymorphism and carotid artery intima-media thickness in a random sample of middle-aged men

Genetic polymorphism of apolipoprotein E (apoE) is an important factor in the development of coronary artery disease but the results concerning apoE genotype and carotid artery atherosclerosis remain controversial. We investigated a random sample of 189 Finnish middle aged men (mean age 54 years, range 50-59) to assess the role of apoE in the process of carotid atherosclerosis. Intima-media thickness (IMT) of the carotid artery wall was measured at three standardised segments (common carotid artery, bifurcation and internal carotid artery) by B-mode ultrasonography. Overall mean IMT value was also calculated. The carriers of E3/2 (n=20) genotype had significantly lower (P<0.01) total cholesterol and LDL cholesterol concentrations than carriers of E3/3 genotype (n=109) or the E4 allele (n=60). ApoE polymorphism was associated with common carotid artery IMT (P=0.034) when adjusted for age and body-mass index (model 1). The carriers of E3/2 had on average 9% (95% CI 0.8-16%, P=0.028) lower common carotid IMT values than the carriers of E3/3. After further adjustment with LDL and HDL cholesterol, systolic blood pressure, lipoprotein (a), apolipoprotein B and pack-years of smoking (model 2) the association was not statistically significant. The overall mean IMT varied significantly with apoE genotype (P=0.03 for model 1 and P=0.07 for model 2), and it was also lowest in the carriers of E3/2 genotype. This suggests that apoE E3/2 genotype is a protective factor in the development of carotid artery atherosclerosis in randomly selected middle-aged men. The favourable effect might be mediated at least partly by the lowering effect of E3/2 genotype on serum cholesterol.

Coronary artery calcification is related to functional polymorphism of matrix metalloproteinase 3: the Helsinki Sudden Death Study

Matrix metalloproteinase 3 (MMP3) is expressed in human coronary atherosclerotic lesions and is known to be involved in degradation of the plaque and to be co-localized with calcium and fibrin deposits in advanced lesions, indicating a possible role of MMP3 in arterial calcification. The MMP3 gene promoter polymorphism leads to low promoter activity 6A6A, intermediate promoter activity 5A6A and high promoter activity 5A5A genotypes. To determine whether these genotypes predict the extent of atherosclerosis we investigated their association with different types of coronary lesions in an autopsy series of 300 middle-aged white Finnish men (aged 35-69 years) from the Helsinki Sudden Death Study (HSDS). Areas of the coronary wall covered with different atherosclerotic lesions were measured and MMP3 genotypes were determined by PCR and minisequencing. In men >/=53 years the mean area of calcified lesion in the most severely affected coronary artery was significantly associated with the MMP3 genotype (P=0.029). Subjects with high promoter activity genotypes had on average larger calcified lesion areas than those with the low-activity genotype. The MMP3 genotype (P=0.025) persisted as an independent predictor of mean calcified lesion area after stepwise adjustment for age, BMI, hypertension, diabetes, number of affected vessels and smoking. These data provide evidence that the proposed effect of MMP3 in the process of atherogenesis may be modified by the MMP3 genotype.

Myeloperoxidase gene variation as a determinant of atherosclerosis progression in the abdominal and thoracic aorta: an autopsy study.

Myeloperoxidase (MPO) is an enzyme that transforms low-density lipoprotein into atherogenic particles. The MPO gene has a promoter polymorphism at position −463, which affects gene transcription and leads to high- (G/G) and low-expression (A/A, A/G) genotypes. To determine if these genotypes are associated with the severity of atherosclerosis, we performed an autopsy study of 300 men aged 33 to 69 years (Helsinki Sudden Death Study). We examined the percentage area of fatty streaks and fibrotic, calcified, and complicated lesions using computer-assisted planimetry. The MPO genotypes were determined by PCR. There were significant interactions of MPO genotype with the mean area of fibrotic (p < 0.01) and calcified (p < 0.05) lesions in the abdominal aorta and in fibrotic lesions in the thoracic aorta (p = 0.003). In the abdominal aorta, men < 53 years with low-expression genotypes had on average a 38.6% larger area of fibrotic lesions and a 43.8% larger area of calcified lesions than did the subjects with the G/G genotype. This association weakened with advancing age. Among men < 53 years, the MPO genotype was an independent predictor of fibrotic (p = 0.037) and calcified (p = 0.001) lesion area in the abdominal aorta after adjustment for age, body mass index, diabetes, hypertension, and smoking. MPO gene variation may modify the extent of advanced atherosclerotic lesions in the human aorta in early middle age.

Association of the endothelial nitric oxide synthase gene polymorphism with risk of coronary artery disease and myocardial infarction in middle-aged men.

Abstract. Nitric oxide (NO), formed by endothelial constitutive nitric oxide synthase (eNOS) maintains endothelium-dependent vasodilatation and also mediates antithrombotic actions. The eNOS gene harbours a common polymorphism in intron 4 (4a/b), and some clinical studies have suggested an association of the rare a-allele with coronary artery disease (CAD) and myocardial infarction (MI). However, contradictory results have also been reported. We studied associations of eNOS polymorphism with CAD and MI in two prospective autopsy series comprising altogether 700 Caucasian Finnish men, who died suddenly. In ANCOVA, no significant differences in areas of atherosclerotic lesions and coronary stenosis percentages were found between men carrying the a-allele (ba+aa) compared with those homozygous for the b-allele. Subjects with the a-allele had significantly lower risk of MI (odds ratio 0.44, 95% confidence interval 0.25–0.77, P=0.004) compared with those carrying the bb genotype. Men with the a-allele also tended to have coronary thrombosis less often (odds ratio 0.43, 95% confidence interval 0.18–1.01, P=0.055). The eNOS gene 4a/b polymorphism was not associated with the extent of coronary atherosclerosis, but the a-allele of the variant seems to protect to some degree against the development of MI.

Radiographic Assessment of Dental Health in Middle-aged Men Following Sudden Cardiac Death

Poor oral health has been suggested to be a risk factor for myocardial infarction. To study if dental pathology might predispose to pre-hospital sudden cardiac death, and using a sum index of panoramic tomography findings, we compared the oral health of middle-aged (33–69 yrs) male victims (Helsinki Sudden Death Study) of sudden cardiac death (n = 117) with that of controls, who died of non-cardiac diseases (n = 63) or suffered unnatural sudden death (n = 120). The mean number of teeth was 15.2, and 17.4% of the men were edentulous. Frequent age-associated findings in dentate victims were fillings (79.9%), horizontal bone loss (72.1%), periapical lesions (45.6%), residual roots (38.2%), and vertical pockets (30.9%). In multivariate analysis with coronary heart disease risk factors and number of teeth as covariates, poor oral health was associated (p = 0.053) with the risk of sudden cardiac death along with age, smoking, and body mass index. This association was especially strong (p = 0.009) among victims < 50 yrs.