Familial patterns of covariation for cardiovascular risk factors in adults- The Victorian Family Heart Study

The Victorian Family Heart Study was established to address the causes of f amilial patterns in cardiovascular risk factors. From 1990 to 1996, a repre sentative population sample of 783 adult families (2,959 individuals), each comprising both parents (40-70 years) and at least one natural adult offsp ring (18-30 years), was recruited in Melbourne, Australia. Included in both generations were 461 monozygotic and dizygotic twins as pairs or singleton s. A multivariate normal model was used for pedigree analysis of height, we ight, body mass index, diastolic and systolic blood pressure, pulse rate, a nd total and high density lipoprotein cholesterol. All traits showed eviden ce for additive genetic variation, explaining from 55% (height) to 26% (pul se) of age- and sex-adjusted variance. An effect persisting into adulthood of shared family environment during cohabitation explained from 39% (body m ass index) to 13% (systolic blood pressure) of variance (not nominally sign ificant for diastolic blood pressure). These shared environmental effects w ere strongest within twin pairs, less so for sibling pairs, and least for p arent-offspring pairs (in which an effect was not observed for weight, dias tolic and systolic blood pressure, and total cholesterol). On a background of genetic influences, there are periods in early life during which the fam ily environment cements long-term correlations between adult relatives in c ardiovascular risk factors.