*these variables were not statistically compared due to the small size of the sample; statistical analysis: ANOVA followed by the Student t test.

The E3E3 genotype has been the most frequent (55%) in the populations studied so far, followed by the E3E4 genotype (26%) 3,31. The results obtained were also similar to those of the northern region of Italy 33. Data on the Italian immigra- tion to Veranópolis point to a greater number of individuals coming from northern Italy; thus, this similarity was ex- pected. To demonstrate this, table VII compares ApoE fre- quencies in different populations or different age groups of these populations, or both 3,4,10,31,33,34. Unfortunately, data on the ApoE frequencies of the Brazilian population are still lacking, which hinders the comparison with the frequencies obtained in the present study. In general, the greater fre- quency of individuals with the E3E4 genotype in Veranopo- lis as compared with that of the Italian populations is nota- ble. Further genetic studies may help to elucidate this phe- nomenon.

vity, were similar for the genotypes analyzed (tab. IV). In re- gard to smoking, less than 3% of the population studied smoked. No specific genotype association was observed (x2 = 0.75, degree of freedom = 1, p = 0.77).

The last analysis of the study involved the assessment of the association between risk factors and cardiovascular morbidity and the most frequent ApoE genotypes. Due to the low frequency of cardiovascular morbidity in the popu- lation studied, those frequencies were grouped (stroke, acute myocardial infarction, intermittent claudication, and angina pectoris) to enable the statistical analysis.

The group of elderly with the E3E3 genotype tended to have a higher number of individuals affected by cardiovascular events, obesity, and hypertension; however, only obesity was statistically significant in the genotypes studied. More E3E3 individuals were obese than were E3E4 individuals.

E3E4 elderly individuals tended more to familial morbi- dity and mortality due to cardiovascular diseases, diabetes mellitus, and dyslipidemia. However, these differences were not statistically significant (fig. 1).

Despite the high frequency of the E4 allele in the elder- ly, no E4E4 genotype was observed. Several studies carried out in other countries suggest the occurrence of a frequen- cy-dependent effect of the E4 allele, ie, the presence of 2 copies of the E4 allele is associated with early mortality. As no elderly individual with this genotype was observed, the data obtained confirm this hypothesis.

Discussion

The analysis of the results suggests the existence of a more complex interaction between ApoE polymorphism and the variables related to the cardiovascular events studied. Genotype-dependent relations, which have not yet been explored, may exist.

FHCVD CVD DM Ob Dislip. Hyp. Comorbidity and morbidity CVD  %90807060504030204446   5922 Deses85 mese47950 —onTilelin. Hew.

In regard to the gene and genotypic frequencies rela- ted to ApoE polymorphism, it is important to emphasize that these frequencies vary according to the population studied. Review studies have shown that the gene frequencies rela- ted to this polymorphism are extremely variable, mainly in regard to the E4 allele frequency 1,2. In Europe, this gene has a gradient distribution, the E4 allele being more frequent in the northern region and less frequent in the southern region. In Asian populations, this allele has a low frequency, unlike that of the African and New Guinea populations 31-33. However, specific studies on the possible causes of this variation are still in their infancy.

Fig. 1 - Comparison of risks for cardiovascular diseases, associated comorbidity, morbidity. FHCVD - familial history for cardiovascular diseases; CVD - sum of cardiovascular diseases observed in the sample investigated (stroke, acute dial infarction, intermittent claudication, and angina pectoris), DM - diabetes litus; Ob - obesity; Dislip - dyslipidemia; Hyp - hypertension.

In general, the gene frequencies observed in the pre- sent study were similar to those reported by other authors.

In regard to the association between blood pressure and the ApoE genotypes, some studies have shown an asso- ciation between systolic blood pressure and the E4E4 and E3E4 genotypes, suggesting that ApoE polymorphism can be a silent factor influencing the increase in blood pressure 31. Other studies, however, did not show this association 32,34. In our study, an inverse association was observed: high diastolic blood pressure in the E3E3 elderly; however, no reference was found about this possible association in the literature. This suggests that a correlation between blood pressure levels and ApoE polymorphism may exist, even though no causal genotype-phenotype relation was ob- served in regard to blood pressure, indicating that other not yet identified genetic-environmental interactions may exist.

individuals and variables of the lipid profile assessed by simple logistic regression and their respective odds ratio Variables X2 P Odds ratio 95% CI LDL-cholesterol (130 mg/dL) 5.82 0.013 2.61 1.04-6.56 Uric acid (6 mg/dL) 6.05 0.007 0.09 0.10-0.78 Fibrinogen (300 mg/dL) 12.21 0.042 2.07 1.20-7.88 Total cholesterol (240 mg/dL) 3.58 0.060 1.23 2.77-5.43

X2- chi-square; CI - confidence interval