A secondary school health promotion intervention had an overall neutral effect on the cardiovascular health of adolescent students in Spain after 4 years in a randomized trial.
Adolescence is a crucial behavioral phase when physical activity (PA) tends to decrease and smoking often starts, so early preventive action to address modifiable cardiovascular (CV) risk factors is needed and schools are a good environment for this intervention.
The Salud Integral Program (SI! Program) includes a multicomponent approach based on healthy eating and PA, with tools to improve assertiveness, self-esteem, and socioemotional skills to make healthier decisions.
The study included 1326 students at 24 schools in Barcelona and Madrid, Spain, who were randomly assigned to one of three groups: a short-term (2-year) intervention (STI) using the SI! Program for those aged 12-14 years, a long-term (4-year) intervention (LTI) for those aged 12-16 years, or the standard curriculum (control).
Using the American Heart Association CV health (CVH) measure that includes seven elements (body mass index, blood pressure, total cholesterol level, fasting blood glucose level, smoking, physical activity, and diet), researchers obtained an overall CVH score ranging from 0 to 14, with a higher score indicating a healthier CVH profile.
The primary endpoints were the between-group differences in the change from baseline at 2-year follow-up and 4-year follow-up.
At the 2-year follow-up, the mean difference in change in CVH score between the control and LTI groups was 0.44 points (95% CI, 0.01-0.87; P = .04), and the difference between the control and STI groups was 0.18 points (95% CI, -0.25 to 0.61; P = .39).
At the 4-year follow-up, the mean difference between the control and LTI groups was 0.12 points (95% CI, -0.19 to 0.43; P = .42), and 0.13 points between the control and STI groups (95% CI, -0.17 to 0.44; P = .38).
Although the difference was nonsignificant, there was a higher dietary score in the LTI group at 2 years, suggesting a modest improvement in dietary habits in at least some participants, the authors note.
As for secondary endpoints, there were no statistically significant within-group differences in any group at any follow-up, and most between-group differences in change in individual CVH metrics were nonsignificant.
Beneficial changes in health factors such as blood pressure and cholesterol are difficult to achieve over a short period, said the authors, adding that an educational program “may require a more suitable primary endpoint and a reintervention to achieve sustained behavioral effects that may therefore result in a meaningful effect on biological parameters.”
An accompanying editorial by Holly C. Gooding, MD, Division of General Pediatrics and Adolescent Medicine, Department of Pediatrics, Emory University School of Medicine, and Liliana Aguayo, MD, PhD, Emory University Rollins School of Public Health, both in Atlanta, said that despite nonsignificant changes, the study introduced “important insights that can inform future implementation efforts.“
The study’s use of a positive youth development approach to encourage healthy behaviors, “fosters adolescents’ competence, confidence, character, connection, and caring for others,” said the editorial writers. The increasingly early onset of major CVD risk factors “urgently requires effective, sustainable, and multilevel interventions,” they write.
The study was carried out by Gloria Santos-Beneit, PhD, Foundation for Science, Health and Education, Barcelona, Spain, and colleagues. It was published online August 2, 2023 in JAMA Cardiology.
Changes in school routines due to the COVID-19 pandemic was a major unpredicted limitation of the study. Though potential loss to follow-up and dropouts were factored into the sample-size calculation, the long trial duration made it more difficult to retain participants. Some participants were likely assessed in nonfasting conditions, although a sensitivity analysis excluding the blood glucose metric from the overall CVH score didn’t alter overall results. Adolescents were often asked to remove accelerometers during training and competition, so PA might have been underestimated in some cases.
The study received support from the SHE Foundation-la Caixa Foundation and the Fundació la Marató de TV3. Santos-Beneit has no relevant conflicts of interest; for disclosures of other study authors, see the paper. Gooding reported receiving grants from the National Heart, Lung, and Blood Institute; Aguayo had no relevant conflicts.