Individuals endorsing higher rates of delay discounting (DD) tend to discount the value of future rewards, such that the perceived value of the future reward, though larger than an immediate reward, is viewed as less valuable. In turn, DD is associated with engaging in poor health behaviors, such as unhealthy diet and low levels of physical activity, both of which may increase risk of developing cardiovascular disease (CVD). Individuals with elevated genetic risk for CVD and higher rates of DD, are likely to be especially vulnerable to developing CVD. This randomized controlled study examined rates of DD among young adults with a family history (FH) of early-onset CVD (i.e., adults with higher genetic risk for CVD; FH+) and without a FH of CVD (FH-). Associations of DD, perceived CVD risk, physical activity, dietary sodium and lipid intake, as well as health behavior intentions were assessed before, immediately following, and one week after a standard educational intervention. In addition, FH was evaluated as a moderator of these associations. High rates of DD were hypothesized to correlate with sodium and lipid consumption, and negatively correlate with perceived risk of developing CVD, level of physical activity, and intention to engage in healthy behaviors. Further, it was hypothesized that FH+ participants randomized to the experimental condition would report greater reductions in DD, sodium and lipid intake, and increases in physical activity, perceived disease risk, and health behavior intentions, compared to FH- participants in the experimental condition, and participants in the control condition.
Fifty-four FH+ and 60 FH- adults between the ages of 18 and 40, with no personal history of CVD were randomized to view either an educational video about CVD, or a control educational video. Questionnaires assessed perceived risk of developing CVD, intention to engage in health behaviors, lipid and sodium intake, as well as physical activity. DD was assessed with the Monetary Choice Questionnaire (MCQ) and the Money Choice Task (MCT). Regression, analysis of variance, mediation, and moderated mediation analyses were conducted to examine differences between FH+ and FH- participants, and hypothesized interactions of variables.
Ninety-nine participants completed all portions of the study. At baseline, FH+ participants reported preference for larger-later-rewards when considering rewards of smaller-sizes with the MCQ, but preference for the overall smaller-sooner-reward with the MCT. Also at baseline, higher rates of DD were associated with consuming a diet higher in lipids, and more frequent engagement in physical activity. FH moderated the relationship between DD and daily sodium consumption at baseline; among FH+ participants, DD was positively associated with sodium intake. Reductions in DD from baseline to post-intervention mediated change in total perceived CVD risk only among FH+ participants. Similarly, increased intention to eat low-sodium foods was mediated by reductions in DD among FH+ participants in the experimental group.
Results suggest that rates of DD are associated with poor health behaviors among both FH+ and FH- young adults, and that DD may play a role in the exacerbation of CVD risk among at-risk young adults. Among FH+ participants, the brief information-based intervention was associated with immediate reductions in DD, but the intervention did not lead to short-term (one-week) health behavior change. Although disease education is commonly used in CVD prevention efforts, it may not be sufficient to influence health beliefs or health behavior among higher-risk young adults. Future longitudinal research should evaluate DD as a predictor of early-onset CVD via poor health behaviors among FH+ young adults. Further development and evaluation of primary prevention CVD interventions is warranted.