GENETIC AND ENVIRONMENTAL-INFLUENCES ON CARDIOVASCULAR-DISEASE RISK-FACTORS IN ADOLESCENTS

Background: Although there is consensus that prevention of cardiovascu lar diseases is a worthwhile activity and that these efforts should be gin in childhood, some controversies remain about the efficacy and tim ing of preventive efforts. Objective: To differentiate the cardiovascu lar risk factors that have a potential to respond to environmental and lifestyle modification. Methods: The sample consisted of 56 monozygot ic and 29 same-sex dyzogotic twin pairs, equally distributed by gender with a mean age of 12.62 years. Systolic and diastolic blood pressure , triceps skinfold thickness, body mass, and fasting blood specimens f or lipid profiles were collected during home visits. Teachers rated th e subjects' Type A behaviors using the Matthews Youth Test for Health. Results: Statistically significant estimates of genetic variance were obtained for cholesterol, triglycerides, high-density lipoprotein cho lesterol, systolic and diastolic blood pressure, and body mass index. Compared with the previous phase of this longitudinal study, higher es timates of genetic variance were observed for components of the lipid profile and blood pressure and lower estimates were observed for Type A behavior variables. Conclusions: Overall, the genetic influence on r isk factors was moderate, leading to the conclusion that the potential to modify risk profiles during the transition from childhood to adole scence is substantial. Attitudes, behaviors, and environmental inducem ents that establish and maintain healthy lifestyles over long periods should be the focus of interventions and further research.