To date, the lifespan of MZ carriers has not yet fully been analysed. Although in the Danish study MZ heterozygosity was associated with increased age, centenarians, the best model of successful ageing (Franceschi et al. 2005), were not studied (Dahl et al. 2003). It is conceivable that lifespan of MZ subjects should depend on the suscepti- bility to COPD, a life-threatening disease. How- ever, the risk of COPD in PiMZ heterozygotes has been analyzed in several studies, without consistent results. Studies performed to date have both supported and refuted an increased risk of COPD in PI MZ individuals, with case control studies typically finding some increased risk for COPD in PI MZ subjects and population based

consisted of 143 Sicilian centenarians, whose age was verified by archival records at the City Hall and/or Church registries. We paid particular attention to the concordance between reported age and personal chronologies (age of marriage and of military service for men, age of first and last pregnancy for women, age of children, among others). They did not have any cardiac risk factors or major age-related diseases (e.g., CAD, severe cognitive impairment, severe physical impair- ment, clinically evident cancer or renal insuffi- ciency), although some had decreased auditory and visual acuity. The characteristics of patient and control groups are reported in Table 1. The Sicilian ethnicity of the participants at the study was established by confirming that all four grandparents were born in Sicily; immigration and intermarriage has historically been rare. The University Hospital Ethics Committee approved the project and an informed consent was obtained from each individual.

Comparison of the DNA sequences of healthy young people with the healthy, extremely old population may reveal genes that heavily partic- ipate in the determination of long life (Bessenyei et al. 2004). Thus, to clarify the role of AAT in CVD and longevity, we have studied the distri- bution of AAT allele variants in acute myocardial infarction (AMI) patients, age-matched controls and centenarians.

Materials and methods

We enrolled 127 patients admitted at the Cardiac Unit of Palermo University Hospital (Italy) as they were affected by AMI. To improve the power of our study, we selected genetically loaded cases having early AMI onset (Marenberg et al. 1994). The diagnosis of AMI was based on typical electrocardiography changes and increased serum activities of relevant enzymes and confirmed by echocardiography and coronary angiography. The healthy age matched control group of 255 subjects was recruited amongst stu- dents or staff personnel who were checked and judged to be in good health based on their clinical history and on blood tests (complete blood cell count, erythrocyte sedimentation rate, glucose, urea nitrogen, creatinine, electrolytes, C reactive protein, liver function tests, iron, proteins, cho- lesterol, triglycerides). The second control group

Blood specimens were collected in tripotassi- um EDTA sterile tubes, DNA extracted (Miller et al. 1998) and processed for genotyping according to published protocols. Our procedure for mutation analysis was modified from the PCR-mediated site-directed mutagenesis method of Tazelaar et al. (1992) according to Lam et al. 1997. Allele and genotypic frequencies were evaluated by gene count and differences in fre- quency among the groups. The v2 test (2 · 2 and 3 · 3 tables, where appropriate) and ODD ratio (OR) with confidence interval (CI) were calcu- lated. The data were tested for the goodness of fit between the observed and expected genotype

Centenarians Controls AMI Men 46 (32.2%) 107 (41.9%) 117 (92.1%) Women 97 (67.8%) 148 (58.1%) 10 (7.8%) Age range >99 20–55 20–46 Positive familial history of coronary Not Applicable 13 (5.1%) 70 (55%) heart disease Current Smokers (Current + Former) Not applicable 51 (20.%) 90 (71%) 60 (23.5%) (108) (85%) History of type 2 diabetes 9 (6.3%) 0 (0%) 21 (16.5%) History of obesity Not applicable 3 (2.4%) 41 (32.3%) Hypertension 18 (12.6%) 6 (2.3%) 35 (27.6%) Blood cholesterol levels > 220 mg/dl 0 (0%) 0 (0%) 74 (58.3%) Triglycerides > 160 mg/dl 0 (0%) 0 (0%) 52 (41%)

frequencies of MZ genotypes and Z alleles was obtained between centenarians and both young controls and AMI patients. The frequency of MZ genotype and Z allele in AMI patients was lower than that observed in young healthy controls, but the datum was not significant. Finally, we per- formed a logistic regression analysis to test the association of genotypes with AMI after taking into account smoking habits, family history of CAD and the presence of type 2 diabetes, obesity, hypertension, hypercholesterolemia and hyper- triglyceridemia. By performing a multiple logistic regression analysis to test the association of MZ genotype with AMI considering the previous risk factors, significant differences in genotype fre- quency were observed between 117 male AMI patients and 107 male young controls and per- sisted between 117 male AMI patients and 46 male centenarians (Table 4). These results indi- cate that the MZ genotype is an independent negative risk factor for developing AMI in the male Sicilian population.

frequencies according to Hardy-Weinberg equi- librium (HWE), by v2 test. Due to the different number of women in the groups under study, lo- gistic regression analysis was performed only in men. We performed a multiple logistic regression analysis to test the association of MZ genotype with AMI taking into account smoking habits, family history of CAD and the presence of type 2 diabetes, obesity, hypertension, hypercholester- olemia and hypertriglyceridemia. The OR (with CI) was calculated as exponential of regression coefficient and its standard error.

Results