Abstract
BackgroundWe investigated whether maternal smoking in the first year of life or any current parental smoking is associated with childhood or adolescent body mass index (BMI).MethodsSecondary analysis of data from a multi-centre, multi-country, cross-sectional study (ISAAC Phase Three). Parents/guardians of children aged 6–7 years completed questionnaires about their children’s current height and weight, whether their mother smoked in the first year of the child’s life and current smoking habits of both parents. Adolescents aged 13–14 years completed questionnaires about their height, weight and current parental smoking habits. A general linear mixed model was used to determine the association between BMI and parental smoking.Results77,192 children (18 countries) and 194 727 adolescents (35 countries) were included. The BMI of children exposed to maternal smoking during their first year of life was 0.11 kg/m2 greater than those who were not (P = 0.0033). The BMI of children of currently smoking parents was greater than those with non-smoking parents (maternal smoking: +0.08 kg/m2 (P = 0.0131), paternal smoking: +0.10 kg/m2 (P < 0.0001)). The BMI of female adolescents exposed to maternal or paternal smoking was 0.23 kg/m2 and 0.09 kg/m2 greater respectively than those who were not exposed (P < 0.0001). The BMI of male adolescents was greater with maternal smoking exposure, but not paternal smoking (0.19 kg/m2, P < 0.0001 and 0.03 kg/m2, P = 0.14 respectively).ConclusionParental smoking is associated with higher BMI values in children and adolescents. Whether this is due to a direct effect of parental smoking or to confounding cannot be established from this observational study.Electronic supplementary materialThe online version of this article (doi:10.1186/s12887-015-0538-x) contains supplementary material, which is available to authorized users.
Highlights
We investigated whether maternal smoking in the first year of life or any current parental smoking is associated with childhood or adolescent body mass index (BMI)
For the children, the basic characteristics of each centre are shown in Additional file 2: Table S1, and for the adolescents, basic characteristics are shown in Additional file 3: Table S2
Exposure to parental smoking In the children, 9.9 % had been exposed to maternal smoking in their first year of life (Additional file 4: Figure S2a). 43.1 % of children were exposed to some kind of current parental smoking (10.4 % both parents, 4.6 % maternal smoking only and 28.1 % paternal smoking only) (Additional file 4: Figure S2b)
Summary
We investigated whether maternal smoking in the first year of life or any current parental smoking is associated with childhood or adolescent body mass index (BMI). Concerns about the future health implications of obesity in childhood are well documented [3, 4] This problem has been identified in low and middle income countries as well as affluent countries [5,6,7]. Maternal smoking during pregnancy has been identified as a risk factor for low birth weight and small-for-gestational-age infants [8, 9] and as a likely contributor to increased body mass index (BMI) in later life [10, 11]. The association between maternal smoking in pregnancy and increased offspring BMI may be due to confounding of other lifestyle habits of smoking parents
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
