Acknowledgments: This work was financed by Ministry of Health Progetto finalizzato 1997: la prevenzione della morbilita per malattie croniche nell'eta avanzata. Il modello dei centenari and Progetto finalizzato 1998: interazioni tra fattori di rischio cardiovascolari e fattori genetici dell'aterosclerosi e della trombosi: un approccio integrato genetico-funzionale in casistiche selezionate and by COFIN 2000-2002 Genetics Determinants of Human Longevity.

The observation that the frequency of the 192 allele is higher in centenarians than in young people seems contradictory to literature data reporting the role of this allele as a risk factor in artery and coronary diseases, carotid stenosis, cardiovascular diseases, vascular dementia. However, the data are still conflicting. Moreover, these discrepancies may be related to different criteria of recruitment, different average age of the sample groups, different experimental design (for example, the fact that in some studies A/B variants have been examined without taking 192 into account other variants of PON1 gene, such as L/M 55 variants). Probably, the population genetic history as well as the presence of other risk factors for CVD play a key role in determining association between A/B alleles and CVD. It is interesting that studies carried out in the Mediterranean area do not support the existence of a significant association.

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