Fibrinogen Polymorphism: The biallelic polymorphism is located in the promoter region of the β-fibrinogen gene. The allele containing a polymorphic cutting site for the restriction enzyme HaeIII identified as G-455, and the allele without the cutting site is identified as A-455. Carriers of the less frequent allele A-455 (=0.20 in the general population) have higher fibrinogen levels (=20% to 30%) than carriers of the G-455 allele.12 The method used was described by Thomas et al. with some modifications. Briefly, a portion of the β-fibrinogen gene, -551 to -109 bp from the start of transcription, was amplified by polymerase chain reaction (PCR) using the primers 5'-ATAGAATAGGGTATGAATTTG-3' and 5'-GAACCATTTTATCATTTAAGC-3' in a 50-μL mixture containing 200 to 500 ng DNA, 0.1 mg/mL BSA, 200 μmol/L of each nucleotide triphosphate, 100 pmol of each primer, 2 mmol/L MgCl2, 10 Tris, 50 mmol/L KCl (pH 8.3), and 2.5 U Taq. Amplification involved 33 cycles of 93°C (20 seconds), 50°C (10 seconds), and 70°C (45 seconds). Subsequently, the PCR product was digested with the restriction enzyme HaeIII (Boehringer Mannheim). Finally, the digestion products were separated by electrophoresis on a 3% agarose gel and stained with ethidium bromide. The fragments of the G-455 allele contained 346 and 96 bp, and the fragment of the A-455 allele contained 442 bp.

Statistical Analysis: The allele and genotype frequencies of the two study groups were compared by χ2 analysis using a method designed for small or 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 in some instances, the numbers of centenarians and control subjects studied are less than 124 and 130, respectively (see Tables).

Results: Table 1 shows that for the fibrinogen and factor VII polymorphisms, there was no significant difference between centenarians 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 more frequent in centenarians than in young individuals (P=.021 and P≤.049, respectively) (Table 112 (9.4) 5G 5G 1 (0.8) 2 (1.6) 353QQ 4G 4G 0 2 (1.6) 4G 5G 2 (1.7) 3 (2.3) 5G 5G 2 (1.7) 2 (1.6) -455GA 353RR 4G 4G 13 (10.9) 6 (4.7) 4G 5G 16 (13.5) 22 (17.1) 5G 5G 2 (1.7) 5 (3.9) 353RQ 4G 4G 

3 (2.5) 

3 (2.3)

4G

5G

10(8.4)

4(3.1)

5G

1(0.8)

5(3.9)

AA-455

353RR

4G

4G

1(0.8)

0

4G

5G

0

2(1.6)

5G

1(0.8)

0

353RQ

4G

4G

0

1(0.8)

4G

3(2.5)

0 

X2=26.88; P=.076.

The results of this study on centenarians regarding gene polymorphisms associated with cardiovascular risk factors are compatible with the belief that the basis of successful aging is complex and multifactorial. It is likely that unidentified factors compensate for potentially unfavorable genotypes in centenarians, such as the association of the genotype "4G" with longevity, which may arise due to a locus counteracting the putative unfavorable effect of elevated PAI-1 levels, offsetting the risk conferred by hypofibrinolysis and creating favorable long-term effects. Additionally, we should consider the possibility of a cohort effect when comparing centenarians with individuals under 30 years old because young individuals may not have been exposed to the same environmental factors as centenarians. It is also possible that among elderly people who escaped atherothrombotic disease, it is actually beneficial to have reduced fibrinolytic activity. 

The general conclusion that can be drawn from the study is that there is no evidence that possession of genotypes associated with circulating levels of fibrinogen, factor VII, and PAI-1 reduces the chance of survival to the age of 100 years without evident atherothrombotic disease. 

From http://ahajournals.org on March 13, 2020, association between triglycerides and the factor VII genotype 353RR was found. Hence, the interaction between triglycerides and PAI-1 genotypes found in patients with non-insulin dependent diabetes mellitus was also present in centenarians. The relatively small sample size is perhaps an explanation for the lack of association between triglyceride levels and the 4G4G genotype in young, healthy individuals.

Acknowledgments: This work was supported in part by CNR grants, Progetto Finalizzato Invecchiamento and MURST grants (60%). We thank Dr. Kathryn Boyd for reading the manuscript critically.