approach requires rich data on health and longevity, which are typically collected in longitudinal studies. A majority of genetic studies of disease phenotypes address particular illnesses, as mandated by the current health care paradigm. These studies often use case-control designs, which prevent rigorous investigation of pleiotropic genetic effects because of the limited number of measured phenotypes. The other problem facing studies of pleiotropic effects is that they can be more susceptible to the effects of other genes (epistasis) or non-genetic factors (gene- environment interaction) – which can partly explain disagree- ments in replications of the results.

polymorphisms, as well as the number of individuals with a given compound genotype. Men with Glu27Glu genotype are somewhat younger (significantly with conventional tests and non-significantly with adjustment for multiple compar- isons) than men with the Gln27Gln genotype. There are no other significant differences between mean ages. The Arg16Gly and Gln27Glu polymorphisms are in modest linkage disequilibrium (LD) with r2 = 0.41 (evaluated using Haploview, v. 4.1 (Barrett et al., 2005)). As a result, the Arg16 allele is tightly linked to the Gln27 allele(butnotviceversa)andtheGlu27alleleistightlylinkedtotheGly16allele(but again not vice versa) (Table 1). Both polymorphisms are in Hardy–Weinberg equilibrium with p = 0.78 (Arg16Gly) and p = 0.86 (Gln27Glu).

In this study, we focus on the effects of common polymorph- isms of the ADRB2 gene, Arg16Gly and Gln27Glu, on the probability of staying free of cancer and cardiovascular diseases, as well as on association of these polymorphisms with overall and healthy longevity and survival. Phenotypic and genotypic information are assessed for participants of the longitudinal Framingham Heart Study Offspring (FHSO) cohort that has been followed up for about 36 years.

2.4. Analyses

TheCoxproportionalhazardsregressionmodelwasusedtoevaluatetherelative risks (RRs) of death and incidence of the selected diseases as well as probability of staying free of a given disease (‘‘survival patterns’’) within the follow-up period through 2007 for carriers of the Arg16Gly and Gln27Glu polymorphisms. Associations of these polymorphisms with longevity-related phenotypes were evaluated using the logistic regression.

2. Data and methods

age. Then the models were adjusted for such potential effect-mediators as systolic (SBP) and diastolic (DBP) blood pressures (mm Hg), smoking (ever smoked), diabetes, body-mass index (BMI; kg/m2), total cholesterol (TC) and high-density lipoprotein (HDL) cholesterol (mg/100 ml) (Jalba et al., 2008; Petrone et al., 2006; Pinellietal.,2006;Pudduetal.,2007). TheabsolutevaluesofSBP,DBP,TC,andHDL were used in the regression models with increments of 10 mm Hg for SBP and DBP, and 10 mg/100 ml for TC and HDL cholesterol. BMI was categorized using the U.S. federal guidelines (Flegal et al., 2005) as underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2), and obesity (>30 kg/m2). Diabetes (present or absent) was defined if the study participant was under treatment with insulin/oral hypoglycemics or the level of fasting blood glucose (cid:2)140 mg/dL (i.e., according to the WHO-1985 guidelines). Both types of analyses provided qualitatively similar results with slightly better estimates in the analyses with full adjustment.

The FHSO cohort of respondents aged 5–70 years residing in Framingham, MA was launched in 1971–1975 with a focus on biological descendants (N = 3514), theirspouses(N = 1576),andonadoptedoffspring(N = 34)oftheparticipantsofthe original Framingham Heart Study (FHS) cohort (Dawber, 1980; Gail and Johnson, 1989) resulting in a total sample of N = 5124 subjects; 52% women (Govindaraju et al., 2008; Kannel et al., 1979). The publicly released limited-access FHSO data available for this study have phenotypic information assessed at six FHSO examinations performed in 1971–1975, 1979–1982, 1984–1987, 1987–1990, 1991–1995, and 1996–1997. The study participants have been followed for the occurrence of certain aging-associated diseases, with emphasis on cardiovascular diseases (CVDs) and cancer, and death through 2007. Onsets of CVDs and cancers were assessed at regular examinations at the FHS clinic and from medical records from outside clinics and hospitalization.

Our analyses show that the Gln27Glupolymorphism ismore relevant to diseases thantheArg16Glypolymorphism.Therefore,wepresenttheresultsfortheGln27Glu polymorphism and show potential mediating/modulating role of the Arg16Gly polymorphism by evaluating the effect of six common compound genotypes of these two polymorphisms (i.e., excluding rare Arg16Gly/Glu27Glu and Arg16Arg/ Gln27Glu genotypes; see Table 1).

2.2. Aging-associated phenotypes and risk factors

We selected CVDs and cancers as the most common aging-associated diseases which were studied on their associations with common variants of the ADRB2 gene. Skin cancers were disregarded in this study. An overall longevity phenotype was definedasreachingacertainoldageattheendofthefollow-upperiod(i.e.,in2007)or atdateofdeath.Forthepurposeofthestudy(seeSection3.3),cut-offsbetweenlong andshortlifewereleftflexiblerangingfromtheyoungestpossibleage(whentoofew individualsdiedbeforethecut-offage)totheoldestpossibleage(whentherearetoo fewindividualsreachingthecut-offage).Individualswhosurvivedcut-offageswere consideredaslong-living(LL)individualscomparedtothosewhodiedbeforeoronthe cut-offage;calledasshort-lived(SL)individuals.Ahealthylongevityphenotypewas considered if LL individuals did not develop cancer and/or CVDs.