The effect of a two-year school-based daily physical activity intervention on a clustered CVD risk factor score-The Sogndal school-intervention study.

Abstract

To evaluate changes in clustered cardiovascular disease (CVD) risk factors in 9-year-old children following a 2-year school-based physical activity intervention. In total, 259 children (age 9.3±0.3years) were invited, of whom 256 participated. The intervention group (63 boys, 62 girls) carried out 60-minute teacher-controlled daily physical activity over two school years. The control group (62 boys, 69 girls) had the curriculum-defined amount of physical education (45minutes twice each week). Of these, 67% (171 total, 91 intervention) successfully completed both baseline and post-intervention of six CVD risk factors: systolic blood pressure (SBP), triglyceride (TG), total cholesterol-to-high-density lipoprotein cholesterol ratio (TC:HDL ratio), waist circumference (WC), the homeostasis model assessment for insulin resistance (HOMA), and peak oxygen uptake (VO2peak ). All variables were standardized by sex prior to constructing a cluster score (sum of z scores for all variables). The effect of the intervention on the cluster score was analyzed using linear multiple regression. The cluster score improved after the intervention (ES=.29). Furthermore, the analyses showed significant effects in favor of the intervention group for systolic blood pressure (ES=.35), total cholesterol-to-HDL-c ratio (ES=.23), triglyceride (ES=.40), and VO2peak (ES=.57). A teacher-led school-based physical activity intervention that is sufficiently long and includes a substantial amount of daily physical activity can beneficially modify children's clustered CVD risk profile.