Background: Families of people with ischemic heart disease (IHD) are likely to share high levels of risk markers and to have similar lifestyle patterns. Teenage children in such families were the focus of a behavioral intervention program.
Methods: Families were randomly allocated to either an "early" or a "late" advice group. The late group and a third "control" group (consisting of families with no cardiovascular disease) received the intervention only after baseline measurements were repeated in all three groups at the end of 12 months. Pedigree analysis was used to compare changes across groups.
Results: The decrease in self-reported total fat intake was greater among teenagers in the early group (mean = -3.38, SE = 1.00) than among those in the late group (mean = -0.58, SE = 1.06), as was the decrease in saturated fat intake (mean = -2.46, SE = 0.56; mean = -0.54, SE = 0.60, respectively). These differences were statistically significant (P < 0.05). There were no differences between these groups for changes in total or high-density lipoprotein cholesterol levels. There was a statistically significant difference between the change in total cholesterol levels in the control group (mean = +0.08, SE = 0.07) and that in the late group (mean = -0.14, SE = 0.11).
Conclusions: The intervention program appears to have made the teenagers aware of high-fat foods, as stated fat intake was significantly lowered, but it was not successful in decreasing blood cholesterol levels. Having a parent with IHD did, however, influence the teenagers' risk-related behavior, leading to a significant reduction in blood cholesterol levels.