Effects of a School-Based Physical Activity Intervention on Cardiometabolic Health Five Years After Cessation

Abstract

While there have been several school-based physical activity (PA) interventions targeting improvement in cardiovascular disease (CVD) risk factors, including cardiorespiratory fitness (CRF), few have assessed the long-term effect on a cardiometabolic health composite score. PURPOSE: To determine the effect of a two-year school-based PA intervention on CVD risk five years after cessation. METHODS: We recruited two elementary schools, assigned to intervention (n=125 children) or control (n=134 children). The intervention school offered 210 min/week more PA than the control school over two consecutive years (4th and 5th grades) during 2004-2007. A follow-up assessment was conducted 5-y post intervention (10th grade) during 2011-2012 where 180-210 (73-85%) children provided valid data. Primary outcomes were several CVD risk factors: triglyceride (TG), total to high-density lipoprotein cholesterol ratio (TC:HDL ratio), insulin resistance (HOMA), systolic blood pressure (SBP), waist circumference (WC), and (CRF measured as) peak oxygen uptake (VO2peak). These variables were analyzed individually and as a composite score through linear mixed models, including random intercepts for children. RESULTS: Analyses revealed significant effects of the intervention five years after cessation for HDL (ES=.22), diastolic BP (ES=.48), VO2peak (ml/ kg/min) (ES=.29), and the composite risk score (ES=.38). These effects were similar to the immediate results following the intervention. In contrast, while TC:HDL ratio initially decreased post intervention (ES=.27), this decrease was not maintained at 5-y follow-up (ES=.09), whereas WC was initially unchanged post intervention (ES=.02), but decreased at 5-y follow-up (ES=.44). CONCLUSION: These data reveal that the significant effects of a two-year school-based PA intervention remained in effect for CVD risk factors five years after cessation of the intervention. As cardiometabolic health can be maintained long-term after school-based PA, this paper demonstrates the sustainability and potential of schools in the primary prevention of future CVD risk in children.