School-Based Exercise Programs and Cardiometabolic Risk Factors: A Meta-analysis.

CONTEXT

The effects of school-based physical activity (PA) programs on different cardiometabolic risk factors and the most appropriate features of PA programs to achieve maximum effectiveness are unclear.

OBJECTIVE

To provide a comprehensive synthesis of the effectiveness of school-based PA interventions on cardiometabolic risk factors in children.

DATA SOURCES

We identified studies from database inception to February 22, 2018.

STUDY SELECTION

We selected studies that were focused on examining the effect of school-based PA interventions on cardiometabolic risk factors in children.

DATA EXTRACTION

Random-effects models were used to calculate the pooled effect size (ES) for the included cardiometabolic risk factors (waist circumference [WC], triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, systolic blood pressure and diastolic blood pressure (DBP), and fasting insulin and glucose).

RESULTS

Nineteen randomized controlled trials (which included 11 988 children aged 3-12 years) were included in the meta-analysis. School-based PA programs were associated with a significant small improvement in WC (ES = -0.14; 95% confidence interval [CI]: -0.22 to -0.07; < .001), DBP (ES = -0.21; 95% CI: -0.42 to -0.01; = .040), and fasting insulin (ES = -0.12; 95% CI: -0.20 to -0.04; = .003).

LIMITATIONS

Authors of few studies described the implementation conditions of their interventions in detail, and compliance rates were lacking in most studies. In addition, results by sex were provided in a small number of studies.

CONCLUSIONS

School-based PA interventions improve some cardiometabolic risk factors in children, such as WC, DBP, and fasting insulin.