Associação entre poluição atmosférica e pressão arterial em crianças e adolescentes : revisão sistemática e metanálise

Abstract

Background: Air pollution has been consistently considered a cardiovascular risk factor in adults. Autonomic disbalance and endothelial dysfunction are plausible mechanisms for induction and perpetuation of arterial hypertension after exposure to atmospheric pollutants. However, scientific information about air pollution effects on cardiovascular system and blood pressure in children are still lacking.

Objectives: To systematically review the association between air pollutants and cardiovascular outcomes in children and adolescents.

Methods: For this systematic review and meta-analysis, comprehensive search was conducted through MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, Latin American Caribbean Health Sciences Literature, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and gray literature, with no date and language limit, to estimate the association between air pollutants and blood pressure in healthy children from zero to 18 years of age. Quality of evidence was assessed for all studies using the Cochrane Reviews standards. Meta-analysis was perfomed using random effects models in order to synthesize the associations.

Results: A total of 13 studies accounting 45,059 participants were included in the systematic review, and three of these studies accounting 314 participants were included in the meta- analysis. In the comparison between the group of children resident in areas with higher level of air pollution and the ones exposed to lower level of air pollution, mean differences of systolic and diastolic blood pressure were 3.93 (95% CI: -0.29 to 8.14), I2 = 87%, and 2.61 (95% CI: 0.10 to 5.11), I2 = 78% respectively. In sensitive analysis, mean difference of systolic blood pressure between the higher exposure group and the lower exposure group was 6.08 (95% CI: 3.68 to 8.49), I2 = 50%, and mean difference of heart rate was -3.12 (95% IC: - 4.11 to -2.12), I2 = 0%. Nine studies (69.2%) were classified as poor or fair quality.

Conclusion: Children exposed to higher levels of atmospheric pollution tend to present elevation of blood pressured and indirect signs of endothelial dysfunction, as compared to youngsters who reside in lower exposure areas. The exact dose-effect relationship of this association and the effects of different types of pollutants still need further studies, from childhood to adult life course. Policies to improve environmental health can contribute for primary cardiovascular prevention in the present and the future.