Prenatal and Passive Smoke Exposure and Incidence of Asthma and Wheeze: Systematic Review and Meta-analysis

Abstract

OBJECTIVES: Exposure to passive smoke is a common and avoidable risk factor for wheeze and asthma in children. Substantial growth in the prospective cohort study evidence base provides an opportunity to generate new and more detailed estimates of the magnitude of the effect. A systematic review and meta-analysis was conducted to provide estimates of the prospective effect of smoking by parents or household members on the risk of wheeze and asthma at different stages of childhood. METHODS:We systematically searched Medline, Embase, and conference abstracts to identify cohort studies of the incidence of asthma or wheeze in relation to exposure to prenatal or postnatal maternal, paternal, or household smoking in subjects aged up to 18 years old. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated by using random effects model. RESULTS:We identified 79 prospective studies. Exposure to pre-or postnatal passive smoke exposure was associated with a 30% to 70% increased risk of incident wheezing (strongest effect from postnatal maternal smoking on wheeze in children aged #2 years, OR = 1.70, 95% CI = 1.24-2.35, 4 studies) and a 21% to 85% increase in incident asthma (strongest effect from prenatal maternal smoking on asthma in children aged #2 years, OR = 1.85, 95% CI = 1.35-2.53, 5 studies).CONCLUSIONS: Building upon previous findings, exposure to passive smoking increases the incidence of wheeze and asthma in children and young people by at least 20%. Preventing parental smoking is crucially important to the prevention of asthma. Pediatrics 2012;129:735-744 AUTHORS:

The association between environmental tobacco smoke exposure and childhood respiratory disease: a review

“…In a recent meta-analysis, comparing antenatal and postnatal smoke exposure on the incidence of asthma and wheeze, children exposed to either antenatal or postnatal tobacco smoke exposure had a 30–80% increased risk of developing wheezing and a 21–85% increased risk of developing asthma [62]. However, the strongest risk for the development of wheezing was in children under 2 years with postnatal tobacco smoke exposure (OR 1.70, 95% CI 1.24–2.35) while the risk of developing asthma was associated with antenatal maternal smoking (OR 1.85, 95% CI 1.35–2.53) [62].…”

“…However, the strongest risk for the development of wheezing was in children under 2 years with postnatal tobacco smoke exposure (OR 1.70, 95% CI 1.24–2.35) while the risk of developing asthma was associated with antenatal maternal smoking (OR 1.85, 95% CI 1.35–2.53) [62]. By contrast, in a large population-based prospective cohort study, continued maternal smoking during pregnancy led to increased risk of early and persistent wheezing (OR 1.24, 95% CI 1.01–1.52; OR 1.48, 95% CI 1.13–1.95) and asthma (OR 1.65, 95% CI 1.07–2.55) [63].…”

Prevención de las enfermedades alérgicas en la infancia: entre la teoría y la realidad

“…19 Induce cambios en el crecimiento pulmonar, hiperreactividad de las vías respiratorias, deterioro de la adaptación inmune a los patógenos virales, disminución del desarrollo del sistema inmune pulmonar y cambios inmunológicos que favorecen el desarrollo de la enfermedad alérgica. 20 Además, la inducción de estrés oxidativo y las modificaciones en la colonización bacteriana de las mucosas provocan mayor penetración de alérgenos.…”

Environmental tobacco smoke exposure and asthma

“…A study that evaluated the effects of maternal smoking during pregnancy on asthma and wheezing in 5,762 school-aged children showed that in utero exposure to maternal smoking was associated with increased prevalence of physician-diagnosed asthma [odds ratio (OR) = 1.8], asthma with current symptoms (OR=2.3), asthma requiring medication use in the previous 12 months (OR= 2.1), lifetime history of wheezing (OR=1.8), and emergency room visits during the previous year (OR=3.4) (11). Also, the exposure to prenatal maternal smoking was associated with increase in risk of wheeze (40%) and asthma (20%) in children aged ≤2 years in a systematic review that included 79 prospective studies (OR=1.41 and OR=1.85) (12). Silvestri et al (13) reported that exposure to maternal prenatal smoking was associated with an increased risk of wheezing in <6-year-olds (OR=1.36) and wheezing or asthma in ≥6-year-olds (OR=1.22) in a systematic review.…”