OBJECTIVE: Numerous epidemiological studies have investigated the effects of short-term and long-term exposure to ambient air pollution on hypertension and blood pressure among children and adolescents. However, the results were controversial. To provide researchers reliable evidence, this meta-analysis was performed.
METHODS: We searched all published studies in four databases examining the effects of particulate matter (PM, PMand PM), nitrogen oxide (NO), sulfur dioxide (SO), ozone (O) and carbon monoxide (CO) on hypertension and blood pressure in children and adolescents. Overall risk estimates associated with per 10 μg/mincrease of air pollution were analyzed by a random-effect model for articles with significant heterogeneity, otherwise, a fixed-effect model was applied. Subgroup analysis was conducted for studies with significant heterogeneity. 10 2.5 1 2 2 3 3
RESULTS: Of 3918 identified literatures, 154 were evaluated in-depth with 15 satisfying inclusion criteria. Increased risk of hypertension was associated with long-term PMexposure (OR = 1.17, 95% confidence interval [CI]:1.13, 1.21). For systolic blood pressure (SBP), significant results were found for short-term PM(β = 0.26, 95% CI: -0.00, 0.53) exposure, long-term PM(β = 1.80, 95% CI: 0.94, 2.65) and PM(β = 0.50, 95% CI: 0.19, 0.81) exposure. The corresponding estimates of diastolic blood pressure (DBP) were 0.32 mmHg (95% CI: 0.19, 0.45) for short-term PMexposure, 1.06 mmHg (95% CI: 0.32, 1.80), 0.34 mmHg (95% CI: 0.11, 0.57) and 0.44 mmHg (95% CI: 0.25, 0.63) for long-term PM, PMand NOexposure, respectively. Stratified analyses showed stronger effects of PMon blood pressure among studies with ≥50% boys' percentage (0.57 mmHg [95% CI: 0.44, 0.70] for SBP, 0.44 mmHg, [95% CI: 0.34, 0.54] for DBP, respectively) and articles using models to estimate exposure (0.90 mmHg [95% CI: 0.20 1.59] for SBP). 10 10 2.5 10 10 2.5 10 2 10
CONCLUSION: Ambient air pollution was associated with higher hypertension prevalence and elevated blood pressure in children and adolescents.
