Early life factors and being overweight at 4 years of age among children in Malmö, Sweden

Early-life exposure to tobacco and childhood adiposity: Identifying windows of susceptibility

BACKGROUND

Early-life exposure to tobacco is associated with obesity, but the most susceptible developmental periods are unknown.

OBJECTIVE

To explore windows of susceptibility in a cohort of 568 mother-child pairs.

METHODS

We measured seven measures of tobacco exposure (five self-reported and two biomarkers) spanning from pre-conception to age 5 years. Mothers self-reported active smoking (pre-conception, 17 weeks, and delivery) and household smokers (5 and 18 months postnatally). Cotinine was measured in maternal urine (27 weeks) and child urine (5 years). Adiposity (fat mass percentage) was measured at birth and 5 years via air displacement plethysmography. Using a multiple informant approach, we tested whether adiposity (5 years) and changes in adiposity (from birth to 5 years) differed by the seven measures of tobacco exposure.

RESULTS

The associations may depend on timing. For example, only pre-conception (β = 3.1%; 95% CI: 1.0-5.1) and late gestation (β = 4.0%; 95% CI: 0.4-7.6) exposures influenced adiposity accretion from birth to 5 years (p for interaction = 0.01). Early infancy exposure was also associated with 1.7% higher adiposity at 5 years (95% CI: 0.1-3.2). Mid-pregnancy and early childhood exposures did not influence adiposity.

CONCLUSIONS

Pre-conception, late gestation, and early infancy exposures to tobacco may have the greatest impact on childhood adiposity.

Maternal body mass index in early pregnancy is associated with overweight and obesity in children up to 16 years of age

AIMS

Childhood obesity is an increasing public health problem. The aim of this study was to investigate the correlation between maternal body mass index in early pregnancy and body mass index in children up to the age of 16 years, and to estimate the prevalence of childhood overweight and obesity in a rural municipality in Sweden.

METHODS

The study population comprised 312 pregnant women who attended the antenatal clinics in Lidköping during the year 1999 and their 319 children. Data on body mass index from antenatal clinics, child health care centres and school health care were used in linear and multinomial logistic regressions adjusted for maternal age, smoking status, and parity.

RESULTS

Overweight or obesity were found in 23.0% of 16-year-olds. The correlation between maternal and child body mass index at all studied ages was positive and significant. Body mass index in 16-year-old boys showed the strongest correlation with maternal body mass index (adjusted r-square = 0.31). The adjusted relative-risk ratio for 16-year old children to be classified as obese as compared to normal weight, per 1 unit increase in maternal body mass index was 1.46 (95% confidence interval 1.29-1.65, p<0.001). Among adolescents with obesity, 37.6% had been overweight or obese at 4 years of age.

CONCLUSIONS

This study confirms the correlation between maternal and child body mass index and that obesity can be established early in childhood. Further, we showed a high prevalence of overweight and obesity in children, especially in boys, in a Swedish rural municipality. This suggests a need for early intervention in the preventive work of childhood obesity, preferably starting at the antenatal clinic and in child health care centres.

The Association of Passive Smoking and Serum Urotensin-II Levels in Children

Urotensin-II (UT-II) is the most powerful vasoconstrictor agent and is known to play a role in heart failure, diabetes, pulmonary hypertension and asthma. The effect of passive smoking on UT-II levels is unknown. The present study aims to evaluate serum UT-II levels in children exposed to passive smoke. The study included a total of 120 children; 47 children not exposed to passive smoke were included in Group 1 (control group), and 73 children exposed to passive smoke were included in Group 2. Serum samples of the participants were stored at -80 °C after centrifugation and were assessed at least two times with high-precision human ELISA kits. Serum UT-II levels were significantly higher in the children exposed to passive smoke than in the children not exposed. Furthermore, Group 2 was grouped according to the number of cigarettes smoked at home per day, type of passive smoking (second-hand smoke or third-hand smoke), and how many people in their family and/or living together smoked. There was a positive correlation between the number of cigarettes they were exposed to per day and serum UT-II levels. Passive smoking in childhood may be associated with high serum UT-II levels.

Association between maternal smoking during pregnancy and offspring overweight in U.S.-born children

BACKGROUND

The criticism of the literature on smoking during pregnancy and offspring overweight was the confounding from postnatal factors. Interaction between gestational age and prenatal maternal smoking has not yet assessed.

METHODS

We used the Third National Health and Nutrition Examination Survey (1988-1994), linked with natality files of US-born singletons aged 2 to 6 years. A body mass index in the 85th percentile or higher were considered overweight, including obesity. Gestational age was dichotomized as preterm (<37 weeks, n = 240) or full-term (n = 2125). Smoking status during pregnancy was ascertained by a questionnaire-based interview during National Health and Nutrition Examination Survey.

RESULTS

The prevalence of offspring overweight and obesity combined was 17.3% (SE = 1.3%). And 24.0% (1.3%) of mothers smoked while pregnant. A significant interaction was observed between maternal smoking and gestational age. In preterm children, a higher prevalence of overweight (34.3% [6.7%]) was found among the offspring of smoking mothers compared to non-smoking mothers (15.8% [3.6%]). After adjustment for socio-demographics, prenatal and postnatal factors, in preterm born offspring, the odds ratio of being born to smoking mothers was 2.46 (95% confidence intervals: 1.13-5.37) among children with overweight/obesity compared to children with healthy weight born to non-smoking mothers. In full-term children, the OR of being born to smoking mothers was 0.72 (0.50-1.03) among offspring with overweight/obesity relative to offspring with healthy weight born to non-smoking mothers.

CONCLUSIONS

Maternal smoking during pregnancy was strongly associated with offspring overweight and obesity in preterm births after control for postnatal factors. Preterm children of smoking mothers should be prioritized for obesity prevention.

A challenging balancing act to engage children and their families in a healthy lifestyle - Nurses' experiences of child-centred health dialogue in child health services in Sweden

AIMS AND OBJECTIVES

To describe nurses' experiences of a child-centred family guided intervention of obesity tested within the child health services targeting children identified with overweight and their caregivers.

BACKGROUND

Interventions aiming to support families towards a healthier lifestyle can lead to decreased risk of overweight evolving into obesity in a child. At the same time, nurses have found dialogues on weight challenging and may therefore avoid them.

DESIGN

Qualitative descriptive inductive design following content analysis applying to the COREQ guidelines.

METHODS

Content analysis was used to analyse 13 individual semi-structured interviews with nurses in the child health service in Sweden after completed training in CCHD, including how to facilitate the dialogue with the use of illustrations.

RESULTS

The theme Health dialogue about weight is a challenging balancing act facilitated by a supportive intervention emerged through eight subcategories in three main categories. Nurses experienced that CCHD with children identified with overweight and their caregivers provoked an emotional response both for themselves and for the caregivers of the child. The training in child-centred health dialogues promoted the nurses' work with structure and professionalism, as the nurses carefully took tentative steps to engage the family for a healthy lifestyle.

CONCLUSIONS

Emotional and practical challenges in performing CCHD still remained among nurses after customised training, which might comprise the child's rights to be involved in his or her own care when the child was identified as overweight. However, training for nurses, including lectures and tutorials, was found to increase the quality and professionalism of performing CCHD by providing structure, tools and tutorial support.

RELEVANCE TO CLINICAL PRACTICE

Customised training and illustrations can support nurses when performing a structured intervention such as child-centred health dialogues.

Secondhand Smoking and Obesity Among Nonsmoking Adolescents Aged 12-15 Years From 38 Low- and Middle-Income Countries

Introduction

Secondhand smoking (SHS) may be a risk factor for obesity in adolescence, but data on the association between SHS and obesity are scarce, especially from low- and middle-income countries (LMICs). Therefore, the aim of this study was to assess the association between SHS and obesity among adolescents aged 12–15 years from 38 LMICs.

Methods

Cross-sectional data from 38 LMICs that participated in the Global School-based Student Health Survey (GSHS) were analyzed. Body mass index was calculated based on measured weight and height. The 2007 WHO Child Growth reference was used to define obesity. SHS was categorized as no exposure, non-daily exposure (ie, 1–6 days), and daily exposure (ie, 7 days) based on the number of days exposed to secondhand smoke in the past 7 days. Multivariable logistic regression and meta-analyses were conducted to assess the associations.

Results

The analyzed sample consisted of 88 209 adolescents aged 12–15 years who never smoked. The overall prevalence of non-daily and daily SHS was 34.2% and 15.7%, respectively. After adjustment for potential confounders, compared with no SHS, there was no significant association between non-daily SHS and obesity (odds ratio [OR] = 0.94; 95% confidence interval [CI] = 0.86–1.02), but adolescents who reported daily SHS were significantly more likely to have obesity (OR = 1.19; 95% CI = 1.06–1.34).

Conclusions

The prevalence of SHS was high among adolescents in LMICs, and daily SHS was associated with a significant increase in odds of obesity. Future studies with longitudinal designs are warranted to assess causality and whether prevention of SHS can reduce the risk of obesity in adolescence.

Implications

In the present large multi-country study on adolescents aged 12–15 years from LMICs, nearly half of the students were exposed to non-daily or daily secondhand smoke. Overall, while non-daily SHS was not significantly associated with obesity, adolescents who reported daily SHS had a significant 1.19 (95% CI = 1.06–1.34) times higher odds of obesity than those who reported no exposure to secondhand smoke. To the best of our knowledge, this is the first multi-country study on SHS and obesity from LMICs, and also the largest study on this topic to date.

Development, implementation and early results of a 12-week web-based intervention targeting 51 children age 5-13 years and their families

Background

Internet-based treatments have proven effective for various health issues. There is a need to scale up interventions targeting children with obesity, also in less densely populated areas where the prevalence in many countries is higher than in urban areas. The aim of this study was to design and implement an internet-based program as an add-on to standard treatment for childhood obesity.

Methods

Web-Childhood Obesity Prevention (Web-COP) was a prospective feasibility study with a pre- post- design. The intervention consisted of four group-based education sessions at the clinic, physical activity on prescription, and a new 12-week internet-based program. Web-COP was offered to children with obesity (International Obesity Task Force Body Mass Index (IOTF-BMI) ≥ 30 kg/m2) and their parents in two counties in Northern Sweden from August 2018 to June 2019. The primary outcome was change in BMI standard deviation score (BMI-SDS).

Results

The study included 55 children 5-13 years of age. The internet-based component was well received, and retention rate was 51/55 (92.7%). Data was analysed for 51 children. Mean BMI-SDS was 3.3 at start and decreased by 0.2, 0.3, and 0.4 at two, four, and six months from baseline. Using a continuous algorithm, 42/51 (81%), children lowered their BMI-SDS and 33/51 (65%) lowered their BMI.

Conclusion

Adding group sessions and an internet-based program to standard care was feasible and two thirds of included children with obesity reduced their BMI.

Intrauterine exposure to perfluorinated compounds and overweight at age 4: A case-control study

Aims

The aims were to investigate the association between maternal serum levels of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS) and perfluorononanoic acid (PFNA) in early pregnancy and overweight in the child at 4 years and to assess potential heterogeneity in exposure effect between strata with different levels of other risk factors for overweight.

Methods

We used a case-control design and included 354 cases (ISO-BMI ≥ 18 kg/m²) and 2 controls per case (ISO-BMI ≤17 kg/m²) from child health care centers in Malmö, Sweden. Controls were selected stratified on risk scores for overweight in a propensity score framework. Maternal serum levels were analyzed in biobanked samples collected by routine around gestational week 14. Logistic regression was used to estimate odds ratios between quartiles of maternal serum levels and child overweight at age 4.

Results

There were no consistent monotonic exposure-response relationships. We found some significant odds ratios in specific quartiles but these were regarded as spurious findings. The absence of an effect was consistent over risk strata.

Conclusions

We did not find evidence of an association between maternal serum levels of PFOS, PFOA, PFHxS and PFNA in early pregnancy and child overweight at age 4. The level of other risk factors for overweight did not affect children’s susceptibility to prenatal PFAS exposure.

Maternal smoking during pregnancy and offspring body mass index and overweight: a systematic review and meta-analysis

Abstract: The present study aimed to conduct a systematic review and meta-analysis to evaluate the evidence on the association of maternal smoking during pregnancy with offspring body composition in childhood, adolescence and adulthood. MEDLINE, Web of Science and LILACS databases were searched. Reference lists were also screened. We included original studies, conducted in humans, that assessed the association of maternal smoking during pregnancy with offspring body mass index (BMI) and overweight in childhood, adolescence and adulthood, published through May 1st, 2018. A meta-analysis was used to estimate pooled effect sizes. The systematic review included 64 studies, of which 37 evaluated the association of maternal smoking during pregnancy with overweight, 13 with BMI, and 14 evaluated both outcomes. Of these 64 studies, 95 measures of effect were extracted and included in the meta-analysis. We verified that the quality of evidence across studies regarding maternal smoking in pregnancy and overweight and BMI of offspring to be moderate and low, respectively. Most studies (44 studies) were classified as moderate risk bias. Heterogeneity among studies included was high and, in the random-effects pooled analysis, maternal smoking during pregnancy increased the odds of offspring overweight (OR: 1.43, 95%CI: 1.35; 1.52) and mean difference of BMI (β: 0.31, 95%CI: 0.23; 0.39). In conclusion, offspring of mothers who smoked during pregnancy have higher odds of overweight and mean difference of BMI, and these associations persisted into adulthood.

Traffic-Related Air Pollution and Child BMI-A Study of Prenatal Exposure to Nitrogen Oxides and Body Mass Index in Children at the Age of Four Years in Malmö, Sweden

Traffic-related air pollution could be a danger to the health of children. Earlier studies have linked prenatal exposure to an increased risk of a range of diseases and negative health outcomes, including overweight and obesity. Presently, a knowledge gap exists in investigating the risk of overweight and obesity among children exposed to lower levels of air pollution in utero. This study aimed to investigate the relationship between prenatal traffic-related air pollution (nitrogen dioxides (NO_x) and traffic density) and childhood overweight and obesity in Malmö, Sweden. A cohort, based on attendance of a four-year check-up examination at Swedish Child Health Care (CHC) centers, and a parent-assessed questionnaire provided data on body-mass index adjusted for four-year-old children (ISO-BMI) as well as socioeconomic and health variables. We estimated exposure by using traffic density and levels of NO_x at the maternal geocoded residential level. Analysis of 5815 children was performed using binary logistic regression models. This study showed no associations of increased risk for childhood overweight or obesity through to prenatal exposure to NO_x in this low-exposure setting. We further suggest analysis of risks related to exposure levels ranging between the ones presented here and those proposed in previous literature.

Risk and Protective Factors for Child Overweight/Obesity Among Low Socio-Economic Populations in Israel: A Cross Sectional Study

Background and Aims: Scientific evidence regarding protective factors that contribute to healthy weight in childhood is limited and is particularly scarce in lower socio-economic populations in different ethnic groups. This study aimed to assess the prevalence of biological, behavioral and psychosocial factors for child overweight/obesity in Jewish and Arab population groups in Israel, and to compare their associations with child overweight/obesity in the two groups. Methods: Children aged 5-6 years were randomly selected from 20 Mother and Child Health clinics in towns and villages of lowest socio-economic ranking in Northern Israel. Children and mothers were invited for a special "One Stop Shop-Preparation for School" visit which included growth measurements. Questionnaires were distributed to mothers for self-report on biological, SES, psychological and lifestyle factors. Perinatal and early nutritional data were retrieved from clinic records. Multivariate analyses using logistic regression models predicting child overweight/obesity were conducted separately for Jewish (N = 371) and Arab (N = 575) children. Results: Overweight/obesity (BMI ≥85th centile) rates were higher in Jewish (25%) than Arab (19%) children. In both Jewish and Arab groups, respectively, maternal BMI (OR = 1.10 [95%CI = 1.04, 1.17]; OR = 1.08 [95%CI = 1.04, 1.13]), and child birthweight (OR = 1.33 [95%CI = 1.04, 1.71]; OR = 1.39 [95%CI = 1.11, 1.73]) were significant risk factors for overweight/obesity, and maternal self-efficacy regarding child's lifestyle was significantly protective (OR = 0.49 [95%CI = 0.28, 0.85]; OR = 0.54 [95%CI = 0.34, 0.85]). Additionally, four other maternal psychological and child behaviors were significantly associated with overweight/obesity in the Jewish group and two child lifestyle behavior factors in the Arab group. Moreover, significant interactions indicating moderation effects were found only in the Jewish group: maternal education and maternal age moderated the effect of maternal BMI on child overweight/obesity. No other moderation of risk factors was found. Discussion: In this study of children from low SES families, protective factors contributed to healthy child weight alongside risk factors for overweight/obesity. They differed between the population groups, and fewer variables explained overweight/obesity in Arab children. Although further expansion of these findings is required they point at the relevance of protective factors, maternal self-efficacy in particular, for understanding childhood obesity in specific ethnic contexts and for planning culturally adapted prevention programs in disadvantaged populations.

An efficient sampling strategy for selection of biobank samples using risk scores

AIM

The aim of this study was to suggest a new sample-selection strategy based on risk scores in case-control studies with biobank data.

METHODS

An ongoing Swedish case-control study on fetal exposure to endocrine disruptors and overweight in early childhood was used as the empirical example. Cases were defined as children with a body mass index (BMI) ⩾18 kg/m² ( n=545) at four years of age, and controls as children with a BMI of ⩽17 kg/m² ( n=4472 available). The risk of being overweight was modelled using logistic regression based on available covariates from the health examination and prior to selecting samples from the biobank. A risk score was estimated for each child and categorised as low (0-5%), medium (6-13%) or high (⩾14%) risk of being overweight.

RESULTS

The final risk-score model, with smoking during pregnancy ( p=0.001), birth weight ( p<0.001), BMI of both parents ( p<0.001 for both), type of residence ( p=0.04) and economic situation ( p=0.12), yielded an area under the receiver operating characteristic curve of 67% ( n=3945 with complete data). The case group ( n=416) had the following risk-score profile: low (12%), medium (46%) and high risk (43%). Twice as many controls were selected from each risk group, with further matching on sex. Computer simulations showed that the proposed selection strategy with stratification on risk scores yielded consistent improvements in statistical precision.

CONCLUSIONS

Using risk scores based on available survey or register data as a basis for sample selection may improve possibilities to study heterogeneity of exposure effects in biobank-based studies.

Environmental Tobacco Smoke: Public Perception of Risks of Exposing Children to Second- and Third-Hand Tobacco Smoke

INTRODUCTION

Extensive evidence exists regarding health risks posed by children's exposure to second-hand smoke, and there is increasing evidence concerning the risks of third-hand smoke. This evidence is most meaningful if the public is aware of these risks and can help curb childhood exposure.

METHODS

Participants were selected at an academic medical center and asked to complete a survey. Responses were compared based on respondents' smoking status and the presence or absence of children in their homes.

RESULTS

A total of 310 adults responded. Nonsmokers and respondents living with children were more likely to see smoking in the home as affecting all the queried health problems (p < .05). Knowledge of the risks of second-hand smoke exposure is limited, and very few respondents perceived risk from third-hand smoke exposure.

DISCUSSION

The widespread lack of awareness of the risks associated with environmental tobacco smoke must be addressed to curb childhood exposure.

Systematic review and meta-analysis of the association between maternal smoking in pregnancy and childhood overweight and obesity

BACKGROUND

By 2020, it is predicted that 60 million children worldwide will be overweight. Maternal smoking in pregnancy has been suggested as a contributing factor. Our objective was to systematically review studies on this, thereby expanding the evidence base for this association.

METHODS

Systematic review with meta-analysis, Prospero Registration number CRD42012002859. We searched PubMed, Embase, Global Health, Web of Science and the Grey literature. We included prevalence, cohort and cross-sectional studies involving full-term, singleton pregnancies. Published and unpublished studies through to 1 January 2015 in all languages, demonstrating an objective overweight outcome up until 18 years of age and data presented as an OR, were included. Quality assessment was undertaken using an adaption of the Newcastle-Ottawa scale. Statistical analysis was performed using Review Manager V.5.3.

FINDINGS

The meta-analysis included 39 studies of 236 687 children from Europe, Australia, North America and South America and Asia. Maternal smoking in pregnancy ranged from 5.5% to 38.7%, with the prevalence of overweight from 6.3% to 32.1% and obesity from 2.6% to 17%. Pooled adjusted ORs demonstrated an elevated odds of maternal smoking in pregnancy for childhood overweight (OR 1.37, 95% CI 1.28 to 1.46, I₂ 45%) and childhood obesity (OR 1.55, 95% CI 1.40 to 1.73, I₂ 24%).

INTERPRETATION

Our results demonstrate an association between maternal prenatal smoking and childhood overweight. This contributes to the growing evidence for the aetiology of childhood overweight, providing important information for policymakers and health professionals alike in planning cessation programmes or antismoking interventions for pregnant female smokers.

Interactions between Diet and Exposure to Secondhand Smoke on the Prevalence of Childhood Obesity: Results from NHANES, 2007-2010

BACKGROUND

Exposure to secondhand smoke (SHS) may increase risk for obesity, but few studies have investigated the joint effects of exposure to SHS and diet.

OBJECTIVES

We examined the interaction of exposure to SHS and diet on the prevalence of obesity among 6- to 19-year-olds who participated in the 2007-2010 National Health and Nutrition Examination Survey.

METHODS

We characterized exposure using a novel biomarker [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)], an established biomarker (cotinine), and self-report. Multinomial logistic regression models examined the association of SHS exposure on the prevalence of overweight and obesity as separate outcomes (compared with normal/underweight). Interaction by diet was assessed by introducing interaction terms (with SHS) of the individual nutrients [dietary fiber, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), vitamin C, and vitamin E] into separate models.

RESULTS

Approximately half of the children had NNAL and cotinine levels above the limit of detection, indicating exposure to SHS. Interaction results suggest that the prevalence of obesity among children with both high exposure to SHS and low levels of certain nutrients (dietary fiber, DHA, or EPA) is greater than would be expected due to the effects of the individual exposures alone. Little or no evidence suggesting more or less than additive or multiplicative interaction was observed for vitamin C or vitamin E. The association between SHS and obesity did not appear to be modified by dietary vitamin C or vitamin E.

CONCLUSIONS

Childhood obesity prevention strategies aimed at reducing SHS exposures and improving diets may exceed the expected benefits based on targeting either risk factor alone.

CITATION

Moore BF, Clark ML, Bachand A, Reynolds SJ, Nelson TL, Peel JL. 2016. Interactions between diet and exposure to secondhand smoke on the prevalence of childhood obesity: results from NHANES, 2007-2010. Environ Health Perspect 124:1316-1322; http://dx.doi.org/10.1289/ehp.1510138.

Motivational Interviewing to Prevent Childhood Obesity: A Cluster RCT

OBJECTIVE

The objective was to evaluate a manualized theory-driven primary preventive intervention aimed at early childhood obesity. The intervention was embedded in Swedish child health services, starting when eligible children were 9 to 10 months of age and continuing until the children reached age 4.

METHODS

Child health care centers in 8 Swedish counties were randomized into intervention and control units and included 1355 families with 1369 infants. Over ∼39 months, families in the intervention group participated in 1 group session and 8 individual sessions with a nurse trained in motivational interviewing, focusing on healthy food habits and physical activity. Families in the control group received care as usual. Primary outcomes were children's BMI, overweight prevalence, and waist circumference at age 4. Secondary outcomes were children's and mothers' food and physical activity habits and mothers' anthropometrics. Effects were assessed in linear and log-binominal regression models using generalized estimating equations.

RESULTS

There were no statistically significant differences in children's BMI (β = -0.11, 95% confidence interval [CI]: -0.31 to 0.08), waist circumference (β = -0.48, 95% CI: -0.99 to 0.04), and prevalence of overweight (relative risk = 0.95, 95% CI: 0.69 to 1.32). No significant intervention effects were observed in mothers' anthropometric data or regarding mothers' and children's physical activity habits. There was a small intervention effect in terms of healthier food habits among children and mothers.

CONCLUSIONS

There were no significant group differences in children's and mothers' anthropometric data and physical activity habits. There was, however, some evidence suggesting healthier food habits, but this should be interpreted with caution.

Effect of the exposure to maternal smoking during pregnancy and childhood on the body mass index until adolescence

OBJECTIVE

Investigate the effect of exposure to smoking during pregnancy and early childhood on changes in the body mass index (BMI) from birth to adolescence.

METHODS

A population-based cohort of children (0-5 years old) from Cuiabá, Midwest Brazil, was assessed in 1999-2000 (n = 2,405). Between 2009 and 2011, the cohort was re-evaluated. Information about birth weight was obtained from medical records, and exposure to smoking during pregnancy and childhood was assessed at the first interview. Linear mixed effects models were used to estimate the association between exposure to maternal smoking during pregnancy and preschool age, and the body mass index of children at birth, childhood and adolescence.

RESULTS

Only 11.3% of the mothers reported smoking during pregnancy, but most of them (78.2%) also smoked during early childhood. Among mothers who smoked only during pregnancy (n = 59), 97.7% had smoked only in the first trimester. The changes in body mass index at birth and in childhood were similar for children exposed and those not exposed to maternal smoking. However, from childhood to adolescence the rate of change in the body mass index was higher among those exposed only during pregnancy than among those who were not exposed.

CONCLUSIONS

Exposure to smoking only during pregnancy, especially in the first trimester, seems to affect changes in the body mass index until adolescence, supporting guidelines that recommend women of childbearing age to stop smoking.

Parental smoking and childhood obesity: higher effect estimates for maternal smoking in pregnancy compared with paternal smoking--a meta-analysis

BACKGROUND

Some studies reported similar effect estimates for the impact of maternal smoking in pregnancy and paternal smoking on childhood obesity, whereas others suggested higher effects for maternal smoking. We performed a meta-analysis to compare the effect of in utero exposure to maternal smoking and that of paternal or household smoking exposure in utero or after birth with mutual adjustment.

METHODS

Meta-analysis of observational studies identified in MEDLINE, EMBASE and Web of Knowledge published in 1900-2013. Study inclusion criterion was assessment of the association of maternal smoking during pregnancy and paternal or household smoking (anyone living in the household who smokes) at any time with childhood overweight and obesity. The analyses were based on all studies with mutually adjusted effect estimates for maternal and paternal/household smoking applying a random-effects model.

RESULTS

Data for 109,838 mother/child pairs were reported in 12 studies. The pooled odds ratios (ORs) for overweight 1.33 [95% confidence interval (CI) 1.23;1.44] (n=6, I2=0.00%) and obesity 1.60 (95% CI 1.37;1.88) (n=4, I2=32.47%) for maternal smoking during pregnancy were higher than for paternal smoking: 1.07 (95% CI 1.00;1.16) (n=6, I2=41.34%) and 1.23 (95% CI 1.10;1.38) (n=4, I2=14.61%), respectively. Similar estimates with widely overlapping confidence limits were found for maternal smoking during pregnancy and childhood overweight and obesity: 1.35 (95% CI 1.20;1.51) (n=3, I2=0.00%) and 1.28 (95% CI 1.07;1.54) (n=3, I2=0.00%) compared with household smoking 1.22 (95% CI 1.06;1.39) (n=3, I2=72.14%) and 1.31 (95% CI 1.15;1.50)] (n=3, I2=0.00%).

CONCLUSIONS

Higher effect estimates for maternal smoking in pregnancy compared with paternal smoking in mutually adjusted models may suggest a direct intrauterine effect.

Early origins of adult disease: approaches for investigating the programmable epigenome in humans, nonhuman primates, and rodents

According to the developmental origins of health and disease hypothesis, in utero experiences reprogram an individual for immediate adaptation to gestational perturbations, with the sequelae of later-in-life risk of metabolic disease. An altered gestational milieu with resultant adult metabolic disease has been observed in instances of both in utero constraint (e.g., from famine or uteroplacental insufficiency) and overt caloric abundance (e.g., from a maternal high-fat, caloric-dense diet). The commonality of the adult metabolic phenotype begs the question of how diverse in utero experiences (i.e., reprogramming events) converge on common metabolic pathways and how the memory of these events is maintained across the lifespan. We and others have investigated the molecular mechanisms underlying fetal programming and observed that epigenetic modifications to the fetal and placental epigenome accompany these reprogramming events. Based on several lines of emerging data in human and nonhuman primates, it is now felt that modified epigenetic signature--and the histone code in particular--underlies alterations in postnatal gene expression and metabolic pathways central to accurate functioning and maintenance of health. Because of the tissue lineage specificity of many of these modifications, nonhuman primates serve as an apt model system for the capacity to recapitulate human gene expression and regulation during development. This review summarizes recent epigenetic advances using rodent and primate (both human and nonhuman) models during in utero development and contributing to adult diseases later in life.

Barriers to and facilitators of nurse-parent interaction intended to promote healthy weight gain and prevent childhood obesity at Swedish child health centers

BACKGROUND

Overweight and obesity in preschool children have increased worldwide in the past two to three decades. Child Health Centers provide a key setting for monitoring growth in preschool children and preventing childhood obesity.

METHODS

We conducted semi-structured interviews with 15 nurses working at Child Health Centers in southwest Sweden in 2011 and 2012. All interviews were tape recorded and transcribed verbatim and imported to QSR N'Vivo 9 software. Data were analyzed deductively according to predefined themes using content analysis.

RESULTS

Findings resulted in 332 codes, 16 subthemes and six main themes. The subthemes identified and described barriers and facilitators for the prevention of childhood obesity at Child Health Centers. Main themes included assessment of child's weight status, the initiative, a sensitive topic, parental responses, actions and lifestyle patterns. Although a body mass index (BMI) chart facilitated greater recognition of a child's deviant weight status than the traditional weight-for-height chart, nurses used it inconsistently. Obesity was a sensitive topic. For the most part, nurses initiated discussions of a child's overweight or obesity.

CONCLUSION

CHCs in Sweden provide a favorable opportunity to prevent childhood obesity because of a systematic organization, which by default conducts growth measurements at all health visits. The BMI chart yields greater recognition of overweight and obesity in children and facilitates prevention of obesity. In addition, visualization and explanation of the BMI chart helps nurses as they communicate with parents about a child's weight status. On the other hand, inconsistent use and lack of quality assurance regarding the recommended BMI chart was a barrier to prevention, possibly delaying identification of overweight or obesity. Other barriers included emotional difficulties in raising the issue of obesity because it was perceived as a sensitive topic. Some parents deliberately wanted overweight children, which was another specific barrier. Concerned parents who took the initiative or responded positively to the information about obesity facilitated prevention activities.

The effect of the home environment on physical activity and dietary intake in preschool children

Background

The effects of the home environment on child health behaviors related to obesity are unclear.

Purpose

To examine the role of the home physical activity (PA) and food environment on corresponding outcomes in young children, and assess maternal education/work status as a moderator.

Methods

Overweight or obese mothers reported on the home PA and food environment (accessibility, role modeling and parental policies). Outcomes included child moderate-vigorous PA (MVPA) and sedentary time derived from accelerometer data and two dietary factors (“junk” and healthy food intake scores) based on factor analysis of mother-reported food intake. Linear regression models assessed the net effect (controlling for child demographics, study arm, supplemental timepoint, maternal education/work status, child body mass index and accelerometer wear-time (for PA outcomes)) of the home environment on the outcomes and moderation by maternal education/work status. Data was collected in North Carolina from 2007–2011.

Results

Parental policies supporting PA increased MVPA time, and limiting access to unhealthy foods increased the healthy food intake score. Role modeling of healthy eating behaviors increased the healthy food intake score among children of mothers with no college education. Among children of mothers with no college education and not working, limiting access to unhealthy foods and role modeling reduced “junk” food intake scores while parental policies supporting family meals increased “junk” food intake scores.

Conclusions

To promote MVPA, parental policies supporting child PA are warranted. Limited access to unhealthy foods and role modeling of healthy eating may improve the quality of the child’s food intake.

Association between body size and blood pressure in children from different ethnic origins

Objective

To assess associations between body size and blood pressure in children (5-6 years) from different ethnic origins.

Method

Five ethnic groups of the ABCD cohort were examined: Dutch (n=1 923), Turkish (n=99), Moroccan (n=187), Black-African (n=67) and Black-Caribbean (n=121). Data on body-mass-index (BMI), waist-to-height ratio (WHtR), fat-mass-index (FMI), and systolic blood pressure (SBP) and diastolic blood pressure (DBP), were collected. Linear regression analysis with restricted cubic splines was used to examine non-linear associations between body size and blood pressure, adjusted for age, sex, height and birth weight.

Results

Ethnic differences were found in associations of BMI with SBP and DBP (SBP: p=0.001 and DBP: p=0.01) and FMI with SBP (p=0.03). BMI and FMI had a relatively large positive association with SBP in Turkish children (BMI: β=2.46mmHg; 95%CI:1.20-3.72; FMI: β=2.41mmHg; 95%CI:1.09-3.73) compared to Dutch (BMI: β=1.31mmHg; 95%CI:0.71-1.92; FMI: β=0.84mmHg; 95%CI:0.23-1.45). Black-Caribbean and Moroccan children showed high blood pressure with low BMI and FMI. Moroccan children showed higher SBP with high BMI and FMI. WHtR was positively associated with SBP and DBP, similar in all ethnic groups. Generally, strongest associations with blood pressure were found for BMI in all ethnic groups.

Conclusion

Ethnic-specific associations between BMI, and FMI and blood pressure are present at young age, with Turkish children showing the highest increase in blood pressure with increasing body size. The higher blood pressure in the Black-Caribbean and Moroccan children with low BMI needs further research. WHtR or FMI do not seem to be associated more strongly to blood pressure than BMI in any ethnic group.

Birth weight and long-term overweight risk: systematic review and a meta-analysis including 643,902 persons from 66 studies and 26 countries globally

BACKGROUND

Overweight is among the major challenging health risk factors. It has been claimed that birth weight, being a critical indicator of prenatal developmental conditions, is related to long-term overweight risk. In order to check this important assumption of developmental and preventive medicine, we performed a systematic review and comprehensive meta-analysis.

METHODS AND FINDINGS

Relevant studies published up to January 2011 that investigated the relation between birth weight and later risk of overweight were identified through literature searches using MEDLINE and EMBASE. For meta-analysis, 66 studies from 26 countries and five continents were identified to be eligible, including 643,902 persons aged 1 to 75 years. We constructed random-effects and fixed-effects models, performed subgroup-analyses, influence-analyses, assessed heterogeneity and publication bias, performed meta-regression analysis as well as analysis of confounder adjusted data. Meta-regression revealed a linear positive relationship between birth weight and later overweight risk (p<0.001). Low birth weight (<2,500 g) was found to be followed by a decreased risk of overweight (odds ratio (OR) =0.67; 95% confidence interval (CI) 0.59-0.76). High birth weight (>4,000 g) was associated with increased risk of overweight (OR=1.66; 95% CI 1.55-1.77). Results did not change significantly by using normal birth weight (2,500-4,000 g) as reference category (OR=0.73, 95% CI 0.63-0.84, and OR=1.60, 95% CI 1.45-1.77, respectively). Subgroup- and influence-analyses revealed no indication for bias/confounding. Adjusted estimates indicate a doubling of long-term overweight risk in high as compared to normal birth weight subjects (OR=1.96, 95% CI 1.43-2.67).

CONCLUSIONS

Findings demonstrate that low birth weight is followed by a decreased long-term risk of overweight, while high birth weight predisposes for later overweight. Preventing in-utero overnutrition, e.g., by avoiding maternal overnutrition, overweight and/or diabetes during pregnancy, might therefore be a promising strategy of genuine overweight prevention, globally.

Maternal educational level, parental preventive behavior, risk behavior, social support and medical care consumption in 8-month-old children in Malmö, Sweden

Background

The social environment in which children grow up is closely associated with their health. The aim of this study was to investigate the relationship between maternal educational level, parental preventive behavior, parental risk behavior, social support, and use of medical care in small children in Malmö, Sweden. We also wanted to investigate whether potential differences in child medical care consumption could be explained by differences in parental behavior and social support.

Methods

This study was population-based and cross-sectional. The study population was 8 month-old children in Malmö, visiting the Child Health Care centers during 2003-2007 for their 8-months check-up, and whose parents answered a self-administered questionnaire (n = 9,289 children).

Results

Exclusive breast feeding ≥4 months was more common among mothers with higher educational level. Smoking during pregnancy was five times more common among less-educated mothers. Presence of secondhand tobacco smoke during the first four weeks of life was also much more common among children with less-educated mothers. Less-educated mothers more often experienced low emotional support and low practical support than mothers with higher levels of education (>12 years of education). Increased exposure to unfavorable parental behavioral factors (maternal smoking during pregnancy, secondhand tobacco smoke and exclusive breastfeeding <4 months) was associated with increased odds of in-hospital care and having sought care from a doctor during the last 8 months. The odds were doubled when exposed to all three risk factors. Furthermore, children of less-educated mothers had increased odds of in-hospital care (OR = 1.34 (95% CI: 1.08, 1.66)) and having sought care from a doctor during the last 8 months (OR = 1.28 (95% CI: 1.09, 1.50)), which were reduced and turned statistically non-significant after adjustment for unfavorable parental behavioral factors.

Conclusion

Children of less-educated mothers were exposed to more health risks, fewer health-promoting factors, worse social support, and had higher medical care consumption than children with higher educated mothers. After adjustment for parental behavioral factors the excess odds of doctor's visits and in-hospital care among children with less-educated mothers were reduced. Improving children's health calls for policies targeting parents' health-related behaviors and social support.