Effect of childhood obesity prevention programs on blood pressure: a systematic review and meta-analysis

Abstract

Background: Childhood overweight and obesity are associated with elevated blood pressure (BP). However, little is known about how childhood obesity lifestyle prevention programs affect BP. We assessed the effects of childhood obesity prevention programs on BP in children in developed countries.

Methods and results: We searched databases up to April 22, 2013, for relevant randomized, controlled trials, quasi-experimental studies, and natural experiments. Studies were included if they applied a diet or physical activity intervention(s) and were followed for ≥ 1 year (or ≥ 6 months for school-based intervention studies); they were excluded if they targeted only overweight/obese subjects or those with a medical condition. In our meta-analysis, intervention effects were calculated for systolic BP and diastolic BP with the use of weighted random-effects models. Of the 23 included intervention studies (involving 18 925 participants), 21 involved a school setting. Our meta-analysis included 19 studies reporting on systolic BP and 18 on diastolic BP. The pooled intervention effect was -1.64 mm Hg (95% confidence interval, -2.56 to -0.71; P=0.001) for systolic BP and -1.44 mm Hg (95% confidence interval, -2.28 to -0.60; P=0.001) for diastolic BP. The combined diet and physical activity interventions led to a significantly greater reduction in both systolic BP and diastolic BP than the diet-only or physical activity-only intervention. Thirteen interventions (46%) had a similar effect on both adiposity-related outcomes and BP, whereas 11 interventions (39%) showed a significant desirable effect on BP but not on adiposity-related outcomes.

Conclusions: Obesity prevention programs have a moderate effect on reducing BP, and those targeting both diet and physical activity seem to be more effective.

Keywords: blood pressure; meta-analysis; obesity; pediatrics; prevention.

Figure 1

Flow diagram of the childhood obesity prevention studies identified and evaluated in the review regarding the intervention effects on blood pressure. * Sum of excluded abstracts exceeds 6715 or 654 because reviewers were not required to agree on reasons for exclusion. DBP, diastolic blood pressure; SBP, systolic blood pressure.

Figure 2

Meta-analysis of the effect of childhood obesity prevention interventions on changes in blood pressures. (1) Systolic blood pressure (mmHg) based on 19 studies. (2) Diastolic blood pressure (mmHg) based on 18 studies. WMD=weighted mean difference.

Figure 2

Meta-analysis of the effect of childhood obesity prevention interventions on changes in blood pressures. (1) Systolic blood pressure (mmHg) based on 19 studies. (2) Diastolic blood pressure (mmHg) based on 18 studies. WMD=weighted mean difference.