Limits...
A longitudinal cohort study of body mass index and childhood exposure to secondhand tobacco smoke and air pollution: the Southern California Children's Health Study.

McConnell R, Shen E, Gilliland FD, Jerrett M, Wolch J, Chang CC, Lurmann F, Berhane K - Environ. Health Perspect. (2014)

Bottom Line: Maternal smoking during pregnancy was associated with estimated BMI growth over 8-year follow-up (0.72 kg/m2 higher; 95% CI: 0.14, 1.31) and attained BMI (1.14 kg/m2 higher; 95% CI: 0.66, 1.62).Growth and attained BMI increased with more smokers in the home.These results suggest a synergistic effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.

ABSTRACT

Background: Childhood body mass index (BMI) and obesity prevalence have been associated with exposure to secondhand smoke (SHS), maternal smoking during pregnancy, and vehicular air pollution. There has been little previous study of joint BMI effects of air pollution and tobacco smoke exposure.

Methods: Information on exposure to SHS and maternal smoking during pregnancy was collected on 3,318 participants at enrollment into the Southern California Children's Health Study. At study entry at average age of 10 years, residential near-roadway pollution exposure (NRP) was estimated based on a line source dispersion model accounting for traffic volume, proximity, and meteorology. Lifetime exposure to tobacco smoke was assessed by parent questionnaire. Associations with subsequent BMI growth trajectory based on annual measurements and attained BMI at 18 years of age were assessed using a multilevel modeling strategy.

Results: Maternal smoking during pregnancy was associated with estimated BMI growth over 8-year follow-up (0.72 kg/m2 higher; 95% CI: 0.14, 1.31) and attained BMI (1.14 kg/m2 higher; 95% CI: 0.66, 1.62). SHS exposure before enrollment was positively associated with BMI growth (0.81 kg/m2 higher; 95% CI: 0.36, 1.27) and attained BMI (1.23 kg/m2 higher; 95% CI: 0.86, 1.61). Growth and attained BMI increased with more smokers in the home. Compared with children without a history of SHS and NRP below the median, attained BMI was 0.80 kg/m2 higher (95% CI: 0.27, 1.32) with exposure to high NRP without SHS; 0.85 kg/m2 higher (95% CI: 0.43, 1.28) with low NRP and a history of SHS; and 2.15 kg/m2 higher (95% CI: 1.52, 2.77) with high NRP and a history of SHS (interaction p-value 0.007). These results suggest a synergistic effect.

Conclusions: Our findings strengthen emerging evidence that exposure to tobacco smoke and NRP contribute to development of childhood obesity and suggest that combined exposures may have synergistic effects.

Show MeSH

Related in: MedlinePlus

Estimated effects of SHS and NRP exposure on attained BMI at ages 10–18 years among long-term residents (n = 1,514 with ≥ 4 years at same residence at time of enrollment in 11 communities with NRP estimates). Differences in mean BMI (95% CIs) at each age were estimated for children with NRP above the median and no history of SHS (high NRP only), children with a history of SHS and NRP below the median (SHS only), and children with a history of SHS and high NRP, compared with a common reference group of children who had low NRP and no history of SHS at enrollment.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4384197&req=5

f2: Estimated effects of SHS and NRP exposure on attained BMI at ages 10–18 years among long-term residents (n = 1,514 with ≥ 4 years at same residence at time of enrollment in 11 communities with NRP estimates). Differences in mean BMI (95% CIs) at each age were estimated for children with NRP above the median and no history of SHS (high NRP only), children with a history of SHS and NRP below the median (SHS only), and children with a history of SHS and high NRP, compared with a common reference group of children who had low NRP and no history of SHS at enrollment.

Mentions: A sensitivity analysis was restricted to the 1,514 participants living at the same address for at least 4 years before study entry in order to determine whether effects would be larger in children with consistent longer-term NRP exposures. For this analysis the association of each exposure category with mean attained BMI was compared with BMI among referent children with neither SHS nor high residential NRP exposure (represented by zero on the x-axis in Figure 2). To illustrate the pattern of estimated effect on attained BMI the model-based estimate was re-centered at each age of follow-up. The association of attained BMI at 18 years with NRP with early-life SHS exposure was larger than that observed in the entire population (in Table 3), and the joint effect estimate accounted for almost an additional 3 kg/m2, compared with children who had neither exposure.


A longitudinal cohort study of body mass index and childhood exposure to secondhand tobacco smoke and air pollution: the Southern California Children's Health Study.

McConnell R, Shen E, Gilliland FD, Jerrett M, Wolch J, Chang CC, Lurmann F, Berhane K - Environ. Health Perspect. (2014)

Estimated effects of SHS and NRP exposure on attained BMI at ages 10–18 years among long-term residents (n = 1,514 with ≥ 4 years at same residence at time of enrollment in 11 communities with NRP estimates). Differences in mean BMI (95% CIs) at each age were estimated for children with NRP above the median and no history of SHS (high NRP only), children with a history of SHS and NRP below the median (SHS only), and children with a history of SHS and high NRP, compared with a common reference group of children who had low NRP and no history of SHS at enrollment.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384197&req=5

f2: Estimated effects of SHS and NRP exposure on attained BMI at ages 10–18 years among long-term residents (n = 1,514 with ≥ 4 years at same residence at time of enrollment in 11 communities with NRP estimates). Differences in mean BMI (95% CIs) at each age were estimated for children with NRP above the median and no history of SHS (high NRP only), children with a history of SHS and NRP below the median (SHS only), and children with a history of SHS and high NRP, compared with a common reference group of children who had low NRP and no history of SHS at enrollment.
Mentions: A sensitivity analysis was restricted to the 1,514 participants living at the same address for at least 4 years before study entry in order to determine whether effects would be larger in children with consistent longer-term NRP exposures. For this analysis the association of each exposure category with mean attained BMI was compared with BMI among referent children with neither SHS nor high residential NRP exposure (represented by zero on the x-axis in Figure 2). To illustrate the pattern of estimated effect on attained BMI the model-based estimate was re-centered at each age of follow-up. The association of attained BMI at 18 years with NRP with early-life SHS exposure was larger than that observed in the entire population (in Table 3), and the joint effect estimate accounted for almost an additional 3 kg/m2, compared with children who had neither exposure.

Bottom Line: Maternal smoking during pregnancy was associated with estimated BMI growth over 8-year follow-up (0.72 kg/m2 higher; 95% CI: 0.14, 1.31) and attained BMI (1.14 kg/m2 higher; 95% CI: 0.66, 1.62).Growth and attained BMI increased with more smokers in the home.These results suggest a synergistic effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.

ABSTRACT

Background: Childhood body mass index (BMI) and obesity prevalence have been associated with exposure to secondhand smoke (SHS), maternal smoking during pregnancy, and vehicular air pollution. There has been little previous study of joint BMI effects of air pollution and tobacco smoke exposure.

Methods: Information on exposure to SHS and maternal smoking during pregnancy was collected on 3,318 participants at enrollment into the Southern California Children's Health Study. At study entry at average age of 10 years, residential near-roadway pollution exposure (NRP) was estimated based on a line source dispersion model accounting for traffic volume, proximity, and meteorology. Lifetime exposure to tobacco smoke was assessed by parent questionnaire. Associations with subsequent BMI growth trajectory based on annual measurements and attained BMI at 18 years of age were assessed using a multilevel modeling strategy.

Results: Maternal smoking during pregnancy was associated with estimated BMI growth over 8-year follow-up (0.72 kg/m2 higher; 95% CI: 0.14, 1.31) and attained BMI (1.14 kg/m2 higher; 95% CI: 0.66, 1.62). SHS exposure before enrollment was positively associated with BMI growth (0.81 kg/m2 higher; 95% CI: 0.36, 1.27) and attained BMI (1.23 kg/m2 higher; 95% CI: 0.86, 1.61). Growth and attained BMI increased with more smokers in the home. Compared with children without a history of SHS and NRP below the median, attained BMI was 0.80 kg/m2 higher (95% CI: 0.27, 1.32) with exposure to high NRP without SHS; 0.85 kg/m2 higher (95% CI: 0.43, 1.28) with low NRP and a history of SHS; and 2.15 kg/m2 higher (95% CI: 1.52, 2.77) with high NRP and a history of SHS (interaction p-value 0.007). These results suggest a synergistic effect.

Conclusions: Our findings strengthen emerging evidence that exposure to tobacco smoke and NRP contribute to development of childhood obesity and suggest that combined exposures may have synergistic effects.

Show MeSH
Related in: MedlinePlus