Dose-Response Associations Between Maternal Smoking During Pregnancy and Subsequent Childhood Obesity: Effect Modification by Maternal Race/Ethnicity in a Low-Income US Cohort

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American journal of epidemiology (Impact Factor: 5.23). 10/2008; 168(9):995-1007. DOI: 10.1093/aje/kwn223
Source: PubMed


Studies suggest that children exposed to cigarette smoke in utero are at risk of becoming obese. Few researchers have evaluated the dose-response association between maternal smoking during pregnancy and childhood obesity or whether this association varies by maternal race/ethnicity. The authors obtained retrospective cohort data by linking records from the Pregnancy Nutrition Surveillance System and the Pediatric Nutrition Surveillance System on 155,411 low-income children born during 1995-2001 in 9 US states and 2 tribal nations. The authors examined maternal smoking status, duration of smoking, quantity of smoking, and both duration and quantity combined. Childhood obesity was based on a body mass index greater than or equal to the 95th percentile for sex and age, assessed at age 2-4 years. Maternal race/ethnicity modified the association between smoking during pregnancy and childhood obesity. Among non-Hispanic White mothers, both duration and quantity of smoking were positively associated with childhood obesity in a dose-response manner. Among non-Hispanic Black mothers, only heavy smoking was positively associated with childhood obesity. Among Hispanics, American Indians/Alaska Natives, and Asians/Pacific Islanders, smoking was not associated with childhood obesity. The inconsistent association between smoking during pregnancy and childhood obesity across race/ethnicity categories merits further investigation into potential explanations for this variation, which may include confounding, reporting bias, or unexplored biologic mechanisms.

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Available from: Andrea J Sharma, Sep 05, 2014
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    • "Maternal prepregnancy BMI, weight gain during pregnancy, smoking during pregnancy, low socioeconomic status, birth weight, increased weight gain during early years, and poor home environment have been reported to predict early childhood obesity [2, 5, 7, 13–15]. However, most of studies in the United States have assessed the prepregnancy and early childhood risk factors among predominantly white populations [16] [17] largely ignoring the African-American and Hispanic populations [18] [19] [20] [21]. We assessed maternal and early childhood risk factors for being obese at 5 years of age for a low-income predominantly African-American cohort. "
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    ABSTRACT: Objective. To identify maternal and early childhood risk factors for obesity and overweight among children at age 5 in the state of Alabama. Methods. We recruited 740 mothers during early pregnancy from University of Alabama Prenatal Clinics in a prospective cohort study and followed them throughout pregnancy. We followed their children from birth until 5 years of age. The main outcome measure was obesity (BMI for age and sex ≥ 95th percentile) at 5 years of age. We used poisson regression with robust variance estimation to compute risk ratio (RR). Results. At the 5th year of followup, 71 (9.6%) of the children were obese and 85 (11.5%) were overweight (BMI ≥ 85th-<95th percentile). In multivariable analysis, maternal prepregnancy overweight (RR: 2.30, 95% CI: 1.29-4.11) and obesity (RR: 2.53, 95% CI: 1.49-4.31), and child's birth weight >85th percentile (RR: 2.04, 95% CI: 1.13-3.68) were associated with childhood obesity. Maternal prepregnancy BMI, birth weight, and maternal smoking were associated with the child being overweight 1-12 cigarettes/day versus 0 cigarettes/day (RR: 1.40, 95% CI: 1.02-1.91). Conclusion. Children of overweight and obese mothers, and children with higher birth weight, are more likely to be obese and overweight at age 5. Maternal smoking 1-12 cigarettes per day is associated with the child being overweight.
    Journal of obesity 09/2012; 2012(3):457173. DOI:10.1155/2012/457173
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    • "Fetal growth variables like birth weight were often used to estimate the role of prenatal exposures on the future risk of obesity but results have not been conclusive, [25]–[27] These growth variables are convenient markers or surrogates for summing the interaction between the fetal environment and genetic influences, and their effects may often be subject to the interaction with other early risk factors, or the selection of different outcomes in childhood.[26], [27] Prenatal factors like maternal gestational diabetes, [28] maternal smoking during pregnancy,[29] and malnutrition [30] have also been associated with obesity in later life. However, the inconsistent associations and variations in the magnitude of these estimates call for more investigations on the upstream causes of obesity during prenatal period. "
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    ABSTRACT: It has been suggested that prenatal stress contributes to the risk of obesity later in life. In a population-based cohort study, we examined whether prenatal stress related to maternal bereavement during pregnancy was associated with the risk of overweight in offspring during school age. We followed 65,212 children born in Denmark from 1970-1989 who underwent health examinations from 7 to 13 years of age in public or private schools in Copenhagen. We identified 459 children as exposed to prenatal stress, defined by being born to mothers who were bereaved by death of a close family member from one year before pregnancy until birth of the child. We compared the prevalence of overweight between the exposed and the unexposed. Body mass index (BMI) values and prevalence of overweight were higher in the exposed children, but not significantly so until from 10 years of age and onwards, as compared with the unexposed children. For example, the adjusted odds ratio (OR) for overweight was 1.68 (95% confidence interval [CI] 1.08-2.61) at 12 years of age and 1.63 (95% CI 1.00-2.61) at 13 years of age. The highest ORs were observed when the death occurred in the period from 6 to 0 month before pregnancy (OR 3.31, 95% CI 1.71-6.42 at age 12, and OR 2.31, 95% CI 1.08-4.97 at age 13). Our results suggest that severe pre-pregnancy stress is associated with an increased risk of overweight in the offspring in later childhood.
    PLoS ONE 07/2010; 5(7):e11896. DOI:10.1371/journal.pone.0011896 · 3.23 Impact Factor
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    • "It is believed that there is a positive dose–response association between both the duration and quantity of maternal smoking and childhood obesity.24 It is important to note, therefore, that not every woman who smoked during early pregnancy continued to smoke up to delivery in this study.24 In our study, women who smoked during early pregnancy comprised women who quit smoking during early pregnancy, those who quit smoking during late pregnancy, and those who continued to smoke up to delivery. "
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    ABSTRACT: Background We previously reported that a number of factors related to maternal lifestyle during early pregnancy, including smoking, are associated with childhood obesity at 5 years of age. In the present study, we investigated whether the association with maternal smoking persisted to the age of 9–10 years. Methods The study population comprised children born between April 1, 1991 and March 31, 1999, and their mothers. The dependent variables—childhood overweight and obesity at 5 and 9–10 years of age—were defined according to internationally acknowledged cut-off values. Maternal smoking during early pregnancy was used as the independent variable. Results Mothers who completed a specifically designed questionnaire gave birth to a total of 1644 infants during the study period. Anthropometric data were collected from 1302 of these children during medical checkups at 9–10 years of age (follow-up rate: 79.2%). Maternal smoking during early pregnancy was associated with obesity in 9- to 10-year-old children (adjusted odds ratio, 1.91; 95% confidence interval, 1.03–3.53). However, the point estimates at the age of 9–10 years were considerably lower than those at the age of 5 years. Conclusions Our results suggest that fetal environment, including exposure to maternal smoking, continues to be associated with childhood obesity at the age of 9–10 years.
    Journal of Epidemiology 05/2009; 19(3):136-142. DOI:10.2188/jea.JE20081012 · 3.02 Impact Factor
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