Statistical Analysis

The allele and genotype frequencies of the two study groups were compared by %2 analysis by a method designed for small even zero populations.15 The odds ratio and 95% confidence intervals were calculated to measure the association between each genotype and being a centenarian. The data were adjusted for sex by multiple logistic regression analysis. The association between triglycerides and genotypes was evaluated by ANOVA. For circumstantial technical reasons, not all the results could be obtained for all the samples, so that in some instances the num bers of centenarians and control subjects studied are <124 and <130, respectively (see Tables).

Results

Table 1 shows that for the fibrinogen and factor VII poly morphisms, there was no significant difference between cen tenarians and control subjects in the allele frequencies or in the frequencies of the six possible genotypes. However, there was a difference for the PAI-1 polymorphism: the 4G allele and the homozygous 4G4G genotype, associated with elevated plasma levels of the fibrinolysis inhibitor, were significantly

Factor VII Polymorphism

The biallelic polymorphism is located in exon 8 of the VII gene and results from a missense mutation, leading to substitution of 353R by Q in the mature protein.3 Factor VII plasma levels are 20% to 25% higher in 353RR homozygotes than in carriers of the 353Q allele, which has a population fre quency of =0.10.3

TABLE 1. Distribution of the Three Polymorphisms of Fibrinogen, Factor VII, and PAI-1 Genes in Centenarians and Young Individuals

Centenarians, Young Individuals, Odds Ratios* Polymorphism n (%) n (%) (95% CI) Fibrinogen Genotypes GG-455 72 (59) 81 (62) 1.0 (reference) GA-455 46(37) 45(35) 1.2(0.7-1.9) AA-455 5(4) 4(3) 1.4(0.4-5.1) X2=0.46, P=.79 Alleles G-455 190(77) 207(79) A"455 56(23) 53(21) 1.2(0.8-1.8) 2=0.44, P=.44 X Factor VII Genotypes 353RR 82(69) 83(65) 1.0 (reference) 353RQ 33(28) 39(30) 0.9(0.5-1.5) 353QQ 4(3) 7(5) 0.6(0.1-2.4) X2=0.92, P=.65 Alleles 353R 197(83) 205(79) 353Q 41(17) 53(21) 0.8(0.5-1.3) X2=0.89, P=.27 PAI-1 Genotypes 5G5G 14(11) 29(23) 1.0 (reference) 4G5G 64(52) 64(49) 2.1(1.0-4.3) 4G4G 45(37) 36(28) 2.6(1.2-5.6) X2=6.01, P=.049 Alleles 5G 92 (37) 122 (47) 4G 154(63) 136(53) 1.5(1.1-2.1) X2=5.04, P=.02

from http://ahajournals.org by on March 13, 2020

•Adjusted for sex by multiple logistic regression.

Discussion

more frequent in centenarians than in young individuals (P=.021 and />=.049, respectively) (Table 1). The odds ratios, which give a measure of the relative chance of subjects with or without a given allele or genotype becoming centenarians, were 1.5 and 2.6 for the 4G allele and 4G4G genotype, respec tively (Table 1). Our population of centenarians was composed mainly of women, with a male-to-female ratio of 1:3. There was no significant sex-related difference in any of the allele or genotype frequencies (data not shown).

Three gene polymorphisms associated with the plasma levels of coagulation and fibrinolysis proteins that help predict atherothrombotic disease have been evaluated in exceptionally long-lived individuals. We investigated poly morphisms of the coagulation factors, fibrinogen and fac tor VII, shown by the prospective Northwick Park Heart to be independent predictors of ischemic heart disease in mid dle-aged individuals.1 Also, because a prospective cohort investigation has shown that high levels of plasma activity are associated with early recurrence of myocardial infarction in young men,16 we investigated a PAI-1 poly morphism. Only a limited amount of blood can be from such elderly persons, and so the simultaneous mea surement of the corresponding plasma proteins was not

In centenarians and control subjects, we also analyzed the distribution of the 27 combinations of the nine possi ble genotypes for fibrinogen, factor VII, and PAI-1 poly morphisms. There was no significant difference between the two groups in the frequency of any combination 2). Some combinations were present only in a small num ber of cases; six combinations were absent in both cente narians and young individuals (Table 2).

homozygous genotypes (AA"455 and 353RR) associated with higher levels of fibrinogen and factor VII were similar centenarians and young individuals. These alleles and geno types are associated not only with high plasma levels of these proteins but also with larger increments when car riers are exposed to environmental triggers such as smok ing (for fibrinogen) and hypertriglyceridemia (for factor VII and PAI-1).2'7 The effect of smoking could not be evaluated in this study because centenarians were non- smokers or had stopped smoking for a period of time enough that any effect of smoking would be offset. In cen tenarians, triglyceride levels were higher than in young indi viduals and were associated with 4G4G genotype of the PAI-1 polymorphism, whereas there was no significant

The effect of smoking on the distribution of the genotypes of the fibrinogen polymorphism was not because centenarians (and control subjects) were or had stopped smoking for >5 years. Mean levels of serum triglycerides were significantly higher in cente narians (n=101) than in young individuals (n=60) versus 74±28 mg/dL, P<.001). In neither group was any significant difference (ANOVA) in triglyceride in relation to the different genotypes of the factor VII poly morphism (Table 3). Mean triglyceride values were in centenarians homozygous for the 4G PAI-1 polymorphism than in those with the 5G5G genotype (P<.05), but this dif ference was not seen in young individuals.

TABLE 3. Triglyceride Levels in the Three Genotypes of the 4G5G and R353Q Polymorphisms

TABLE 2. Distribution of Genotype Combinations in Centenarians and Control Subjects