Published online by Cambridge University Press: 01 August 2014
A total of 198 pairs of monozygotic twins reared apart and together were surveyed on their lifestyle and blood pressure through mailed questionnaires. The age of the subjects ranged from 47 to 87 years. The intrapair concordance rate on blood pressure increased from 51% (age of separation 0-5) to 78% (age of separation 26 and over) as the age of separation advanced. The concordance rate on occupation was 59% at the age of separation 0-5 and 87% at the age of separation 26 and over. The intrapair concordance on the food intake (egg, meat, fish, milk and salty seasoning) was positively correlated with the age of separation. Hayshi's quantification theory III (multivariate analysis) was used to claryfy the lifestyle pattern in 39 MZ pairs discordant on blood pressure. There were three factors (meat, milk and occupation) which were closely related with each other in the “non-hypertensive” twins, while lifestyle were not patterned in the “hypertensive” twins. The concordance rate of these three items increased along with the rise of concordance rate of blood pressure as the age of separation advanced.