Stability of the Association between Birth Weight and Childhood Overweight during the Development of the Obesity Epidemic

Gender and educational stage-specific association of birth weight with overweight and obesity among children and adolescents aged 7-18 years: a school-based cross-sectional study

OBJECTIVES

To investigate the associations between birth weight and overweight/obesity in school-aged children and adolescents according to different gender and educational stages, and explore the interactions among the lifestyle factors.

DESIGN

Cross-sectional study.

SETTING

Henan Province in China.

PARTICIPANTS

A total of 27 009 children and adolescents aged 7-18 years were included.

PRIMARY OUTCOME MEASURES

Anthropometric parameters were measured and characteristics were collected by questionnaires. Logistic regression analysis was used to estimate the ORs and corresponding 95% CIs of overweight/obesity with birth weight. The relative excess risk due to interaction (RERI) and the attributable proportion of interaction (AP) indices were used to measure additive interaction.

RESULTS

In the adjusted logistic regression models, the overall population with high birth weight (HBW) (adjusted ORs 2.866, 95% CI 1.563 to 3.728) had an increased risk of overweight/obesity compared with those with normal birth weight (NBW), and the associations differed by gender-specific and educational stage-specific factors. When stratified by gender, children and adolescents with HBW had a higher risk of overweight/obesity as compared with the NBW group (adjusted ORs 2.582 and 2.356; 95% CIs 1.413 to 3.579 and 1.097 to 2.934, boys and girls, respectively). According to different educational stages, HBW was positively associated with an increased risk of overweight/obesity compared with the NBW group. The adjusted ORs of the three groups were 2.757 (95% CI 1.483 to 3.658), 2.317 (95% CI 1.451 to 2.795) and 2.216 (95% CI 1.532 to 2.873), respectively. In addition, we found the HBW group with insufficient physical activity time had significantly higher risk of overweight/obesity (OR 2.165, 95% CI 1.352 to 3.378) in the overall population. As expected, a significant additive interaction was found between birth weight and insufficient physical activity time (RERI 2.289, 95% CI 0.678 to 3.576; AP 0.723, 95% CI 0.521 to 1.126).

CONCLUSIONS

HBW was significantly associated with an increased risk of overweight/obesity in school-aged children and adolescents, and the associations differed by gender-specific and educational stage-specific factors. Notably, HBW possibly interplayed synergistically with insufficient physical activity time to increase the risk of overweight/obesity across gender and educational stages.

Assessing Moroccan physician knowledge and practices regarding maternal obesity's impact on childhood obesity: Implications for prevention and intervention

BACKGROUND

Childhood obesity is a growing global concern with far-reaching health implications. This study focuses on evaluating the knowledge and practices of physicians in Morocco regarding the link between maternal obesity and childhood obesity. Despite the increasing prevalence of childhood obesity worldwide, this issue remains inadequately addressed in the Moroccan context.

AIM

To assess the awareness and practices of physicians in Morocco concerning the connection between maternal obesity and childhood obesity.

METHODS

The research encompasses a comprehensive survey of practicing physicians, revealing significant gaps in awareness and practices related to maternal obesity.

RESULTS

Notably, a significant portion of doctors do not provide adequate guidance to overweight pregnant women, highlighting the urgency for targeted educational programs.

CONCLUSION

In conclusion, this research illuminates critical areas for improvement in tackling childhood obesity in Morocco. By addressing these gaps, fostering awareness, and enhancing medical practices, the healthcare system can contribute significantly to preventing childhood obesity and improving the overall health of future generations.

Ultra-Processed Food as Mediator of the Association between Birthweight and Childhood Body Weight Outcomes: A Retrospective Cohort Study

Previous studies have shown conflicting findings regarding the association between birthweight and childhood adiposity. We aimed to explore the interaction between ultra-processed food (UPF) and birthweight and its associations with bodyweight markers. The retrospective analysis of data from a Multicity Cohort Study across eastern China was conducted. UPF was computed as percentage of the energy intake and categorized into quartiles. Birthweight was categorized into low (LBW), normal (NBW) and high (HBW). The BMI z-score was calculated using the lambda-mu-sigma method. The sex- and age-specific BMI cutoff points were used to define weight status. Generalized linear models were used to examine modification effects and were performed after adjustment for covariates. The mean percentage of energy intake from UPF was 27.7% among 1370 children. Of all children, 2.3% and 21.4% were born with LBW and HBW, respectively. HBW was a permanent risk for high BMI measures, while LBW was associated with increased BMI measurements only by the addition of the interaction term. The subgroup analysis revealed that HBW and LBW were positively associated with BMI measurements in the lowest UPF intake (Q1), while HBW was related to high BMI measures in Q4. Our findings support efforts to recommend limiting UPF intake, especially for LBW children.

Overweight and obesity in preschool children in Turkey: A multilevel analysis

Childhood obesity/overweight is a worldwide concern and its prevalence is increasing in many countries. The first aim of this study is to analyse the trends in overweight and obesity among children under the age of five in Turkey based on the new World Health Organization (WHO) standards, using data from the 'five-round of the Turkey Demographic and Health Surveys' (TDHSs). The second aim is to examine whether or not the maternal/household and individual-level factors are associated with overweight/obesity using TDHS 2003, 2008, and 2013 datasets. A total sample of 14,231 children under the age of five were extracted from the TDHS in 1993, 1998, 2003, 2008, and 2013 to determine the prevalence of the trend. Pooled data from 8,812 children were included in the analysis to examine factors associated with overweight/obesity. Taking into account the clustered data structure, multilevel logistic regression models were utilised. In 1993, 1998, 2003, 2008, and 2013 the prevalence of overweight children was 5.3%, 4.9%, 10.0%, 11% and 11.6%, respectively. The factors that were independently associated with overweight/obesity were as follows: living in single-parent households (adjusted odds ratio (aOR) = 2.27, 95%CI = 1.21-4.26), compared to living in dual-parent households; having an obese mother (aOR = 4.25, 95%CI = 1.73-10.44), overweight mother (aOR = 3.15, 95%CI = 1.29-7.69), and a normal-weight mother (aOR = 2.70, 95%CI = 1.11-6.59) compared to having an underweight mother; being aged between 13-24 months (aOR = 1.72, 95%CI = 1.30 to 2.27), compared to being aged 0-12 months; male gender (aOR = 1.30, 95%CI = 1.11 to 1.53); being stunted (aOR = 2.18, 95%CI = 1.74 to 2.73); high birth weight (aOR = 1.55, 95%CI = 1.08 to 2.23) compared to low birth weight. In addition, overweight was higher in children of mothers who had completed primary school (aOR = 1.21, 95%CI = 1.01 to 1.59) than children of mothers who had not completed primary school. These findings reveal that, over the years, there has been a substantial increase in obesity/overweight among children which demonstrates the importance of evaluating the overweight indicators at the maternal/household level.

Gestational age and trajectories of body mass index and height from birth through adolescence in the Danish National Birth Cohort

Preterm birth is associated with smaller body dimensions at birth. The impact on body size in later life, measured by body mass index (BMI) and height, remains unclear. A prospective register-based cohort study with 62,625 singletons from the Danish National Birth Cohort born 1996-2003 for whom information on gestational age (GA) at birth, length or weight at birth, and at least two growth measurements scheduled at the ages of 5 and 12 months, and 7, 11 and 18 years were available. Linear mixed effects with splines, stratified by sex, and adjusted for confounders were used to estimate standardised BMI and height. GA was positively associated with BMI in infancy, but differences between preterm and term children declined with age. By age 7, preterm children had slightly lower BMI than term children, whereas no difference was observed by adolescence (mean difference in BMI z-score - 0.28 to 0.15). GA was strongly associated with height in infancy, but mean differences between individuals born preterm and term declined during childhood. By adolescence, the most preterm individuals remained shorter than their term peers (mean difference in height z-score from - 1.00 to - 0.28). The lower BMI in preterm infants relative to term infants equalizes during childhood, such that by adolescence there is no clear difference. Height is strongly positively associated with GA in early childhood, whilst by end of adolescence individuals born preterm remain slightly shorter than term peers.

Epidemiology of Obesity

Obesity is in theory defined on the basis of the excess health risk caused by adiposity exceeding the size normally found in the population, but for practical reasons, the World Health Organization (WHO) has defined obesity as a body mass index (weight (kg)/height (m)²) of 30 or above for adults. WHO considers the steep increases in prevalence of obesity in all age groups, especially since the 1970s as a global obesity epidemic. Today, approximately 650 million adult people and approximately 340 million children and adolescence (5-19 years) suffer from obesity. It is generally more prevalent among women and older age groups than among men and younger age groups. Beyond the necessity of availability of food, evidence about causes of obesity is still very limited. However, studies have shown that obesity 'runs in families', where both genetics and environmental, and especially social, factors play important roles. Obesity is associated with an increased risk of many adverse medical, mental and social consequences, including a strong relation to type 2 diabetes. Type 2 diabetes and related metabolic syndrome and diseases are major contributors to the excess morbidity and mortality associated with obesity.

Relationship between caesarean section delivery and risk of overweight/obesity among children aged 6–23 months in the Tamale Metropolis of Ghana

The recent exponential increase in caesarean section (CS) rates in many countries including Ghana requires an understanding of the potential long-term consequences on child health. The present study investigated the relationship between CS delivery and risk of childhood overweight/obesity. A retrospective cohort study was conducted from October 2019 to March 2020 in Ghana. Using multi-stage sampling, 553 mother–child pairs aged 6–23 months were selected from ten health facilities during child welfare clinic (CWC) services. We assessed the association between delivery mode (caesarean v. vaginal) and subsequent body mass index for age (BMI/age Z-score) using hierarchical multivariable linear regression analysis. The prevalence of overweight/obesity (BMI/age Z-score > +2 sd) in children was 3⋅6 %. After adjusting for maternal gestational weight gain, macrosomia and child feeding practices, children who were born through CS had mean BAZ which was 0⋅105 standard units significantly higher than their colleagues who were delivered through normal vaginal [beta coefficient (β) 0⋅105, (95 % CI 0⋅03, 0⋅55)]. CS birth was also associated with 3⋅2 times higher odds of overweight/obesity than vaginal delivery (AOR 3⋅23; 95 % CI 1⋅14, 9⋅13). Consequently, CS delivery was associated positively with increased body mass (adiposity) in the study sample. The association between CS delivery and risk of childhood obesity was attenuated after adjusting for macrosomia. These results would be important for informing clinicians and expectant mothers in considering CS delivery.

Leptin, Obesity Parameters, and Atopy Among Children with Asthma

Leptin, as a major adipokine, positively correlates with the body's fat, while atopy is an important feature in the development of childhood asthma. We aimed to evaluate the relationship between leptin, parameters of obesity, and atopy in children with asthma. The study included 112 children (73 boys, 39 girls, mean age 11.1±2.4). 41 were overweight, 38 had asthma and a normal body mass index (BMI), and 33 were overweight asthmatics. Serum leptin levels, BMI, waist circumference (WC), and waist to hips ratio (WHR) were measured. Skin prick test (SPT)/CAP, total serum IgE, fractional exhaled nitric oxide (FeNO), and pulmonary function tests were performed. In asthmatic children, serum leptin median level was 9.2±16.2 ng/ml, in overweight children was 30.6±21.6 ng/ml, and in overweight asthmatics was 31.1±20.3 ng/ml with a significant difference between the groups (p=0.0374), yet with a significantly lower median level in the group of children with asthma compared to the overweight children: with asthma (p=0.00001) and without asthma (p=0.00001). In the three groups of patients, BMI and WC displayed a significant positive correlation with leptin (for BMI r=0.652 vs. r=0.530 vs. r=0.563, respectively and for WC r=0.508 vs. r=0.426 vs. r=0.527, respectively). No significant correlations of leptin within atopy parameters (Eo, IgE, SPT/CAP, FeNO) in all three analyzed groups (p>0.05) was detected. Conclusion: Atopy was not confirmed as an underlying mechanism of the association between asthma and being overweight. Leptin had a significant linear correlation as a parameter of central obesity with BMI and WC in all three groups, but not with WHR.

Birth weight and childhood obesity: effect modification by residence and household wealth

BACKGROUND

There are both genetic and environmental factors which contribute to a child's chances of being obese. When low birth weight (LBW) has been specifically evaluated relative to its association with childhood obesity, the results have produced conflicting findings. This study aims to describe the relationship between birth weight and childhood obesity and investigate the influence that residence and household wealth has on this relationship.

METHODS

I performed a secondary analysis on the 2013 Riskesdas (or Basic Health Research), a cross-sectional, nationally representative survey of the Indonesian population. Height, weight, information regarding child's birth weight, and basic characteristics of the study population were collected from parents with children aged 0 to 5 years (n = 63,237) in 2013. The exposure was child's birth weight and the outcomes were child's current weight, BMI z-score, and obesity. Data were analyzed by using multiple linear regression and multiple logistic regression.

RESULTS

I found a significant increase in the weight, BMI z-score, and risk of childhood obesity to be associated with LBW. LBW children in rural area were associated with higher BMI z-score (mean ± standard error: 1.44 ± 0.02) and higher odds (odds ratio (95% confidence interval): 7.46 (6.77-8.23)) of obesity than those in urban area. LBW children from low class families were associated with higher BMI z-score (1.79 ± 0.04) and had higher odds (14.79 (12.47-17.54)) of obesity than those from middle class and wealthy families.

CONCLUSIONS

Effective prevention and intervention to childhood obesity as early as possible are imperative. As far as this study was concerned, efforts, policies, and targets are required to reduce the prevalence of LBW. Children born of LBW, who live in a rural area and from low income families, should be emphatically intervened as early as possible.

Relationship between rs9939609 FTO polymorphism with waist circumference and body fat is moderated by ponderal index at birth in youth

OBJECTIVE

The goal of this study was to analyze whether the relationship between the rs9939609 polymorphism of the fat mass and obesity-associated gene (FTO) with nutritional status is moderated by the ponderal index (PI) at birth in children and adolescents.

METHODS

A cross-sectional study evaluated 382 schoolchildren aged 6-17 years. Anthropometric variables such as waist circumference (WC), body mass index (BMI) and body fat percentage (BF%) were used to assess nutritional status. Weight and height at birth were used for the PI calculation, which was divided into tertiles (lower, middle and upper). To compare the continuous variables between genotypes of the rs9939609 polymorphism, a recessive model (TT/AT vs. AA) and covariance analysis (ANCOVA) were used.

RESULTS

The AA genotype of the rs9939609 polymorphism was associated with higher WC in schoolchildren born with lower PI (β = 4.40; p = .048). However, for BF%, the genotype association was found in the upper PI tertile (β = 7.35; p = .040).

CONCLUSION

The relationship between WC and BF% with rs9939609 polymorphism (FTO) seems to be moderated by PI at birth. This is an important insight, since the data for intrauterine growth, genetic factors and the presence of obesity in children and adolescents are still contradictory.

Overweight in childhood of exclusively breastfed infants with a high weight at 5 months

High infant weight increases the risk of childhood overweight, while breastfeeding may reduce the risk. However, some infants have a very high weight gain even though they are exclusively breastfed. We examined the risk of a high body mass index (BMI) and overweight in childhood for infants ≥2.5 SD above the median weight-for-age (WAZ) at age 5 months according to duration of exclusive breastfeeding (≤2, >2 to <4 or ≥4 months). The study is based on 13,401 7-year-old and 9,819 11-year-old children enrolled into the Danish National Birth Cohort (born 1997-2003). Linear and logistic regression analyses were used to examine the associations while adjusting for presumed confounders including birth weight. The results showed that infants ≥2.5 SD at 5 months, breastfed exclusively ≤2, >2 to <4 or ≥4 months had adjusted odds ratios (ORs) for overweight at age 7 at 3.67 (95% confidence interval [CI] [2.10, 6.43]), 3.42 (95% CI [2.32, 5.04]) and 3.19 (95% CI [1.90, 5.36]) respectively, when compared with infants <2.5 SD WAZ exclusively breastfed ≥4 months. The corresponding results for BMI z-scores were 0.82 (95% CI [0.60, 1.04]), 0.63 (95% CI [0.48, 0.78]) and 0.57 (95% CI [0.38, 0.77]). For the ≥2.5 SD infants, the differences in risk of overweight and BMI according to duration of exclusive breastfeeding were neither significantly different among the 7-year nor among the 11-year-old children. A high infant weight increases the odds of overweight and is associated with a higher BMI in childhood. Whereas the odds and BMI z-scores tended to be lower for those exclusively breastfed longer, the differences were not statistically significant.

Maternal and infant prediction of the child BMI trajectories; studies across two generations of Northern Finland birth cohorts

BACKGROUND/OBJECTIVE

Children BMI is a longitudinal phenotype, developing through interplays between genetic and environmental factors. Whilst childhood obesity is escalating, we require a better understanding of its early origins and variation across generations to prevent it.

SUBJECTS/METHODS

We designed a cross-cohort study including 12,040 Finnish children from the Northern Finland Birth Cohorts 1966 and 1986 (NFBC1966 and NFBC1986) born before or at the start of the obesity epidemic. We used group-based trajectory modelling to identify BMI trajectories from 2 to 20 years. We subsequently tested their associations with early determinants (mother and child) and the possible difference between generations, adjusted for relevant biological and socioeconomic confounders.

RESULTS

We identified four BMI trajectories, 'stable-low' (34.8%), 'normal' (44.0%), 'stable-high' (17.5%) and 'early-increase' (3.7%). The 'early-increase' trajectory represented the highest risk for obesity. We analysed a dose-response association of maternal pre-pregnancy BMI and smoking with BMI trajectories. The directions of effect were consistent across generations and the effect sizes tended to increase from earlier generation to later. Respectively for NFBC1966 and NFBC1986, the adjusted risk ratios of being in the early-increase group were 1.08 (1.06-1.10) and 1.12 (1.09-1.15) per unit of pre-pregnancy BMI and 1.44 (1.05-1.96) and 1.48 (1.17-1.87) in offspring of smoking mothers compared to non-smokers. We observed similar relations with infant factors including birthweight for gestational age and peak weight velocity. In contrast, the age at adiposity peak in infancy was associated with the BMI trajectories in NFBC1966 but did not replicate in NFBC1986.

CONCLUSIONS

Exposures to adverse maternal predictors were associated with a higher risk obesity trajectory and were consistent across generations. However, we found a discordant association for the timing of adiposity peak over a 20-year period. This suggests the role of residual environmental factors, such as nutrition, and warrants additional research to understand the underlying gene-environment interplay.

Human embryonic stem cells as an in vitro model for studying developmental origins of type 2 diabetes

The developmental origins of health and diseases (DOHaD) is a concept stating that adverse intrauterine environments contribute to the health risks of offspring. Since the theory emerged more than 30 years ago, many epidemiological and animal studies have confirmed that in utero exposure to environmental insults, including hyperglycemia and chemicals, increased the risk of developing noncommunicable diseases (NCDs). These NCDs include metabolic syndrome, type 2 diabetes, and complications such as diabetic cardiomyopathy. Studying the effects of different environmental insults on early embryo development would aid in understanding the underlying mechanisms by which these insults promote NCD development. Embryonic stem cells (ESCs) have also been utilized by researchers to study the DOHaD. ESCs have pluripotent characteristics and can be differentiated into almost every cell lineage; therefore, they are excellent in vitro models for studying early developmental events. More importantly, human ESCs (hESCs) are the best alternative to human embryos for research because of ethical concerns. In this review, we will discuss different maternal conditions associated with DOHaD, focusing on the complications of maternal diabetes. Next, we will review the differentiation protocols developed to generate different cell lineages from hESCs. Additionally, we will review how hESCs are utilized as a model for research into the DOHaD. The effects of environmental insults on hESC differentiation and the possible involvement of epigenetic regulation will be discussed.

Adverse birth outcomes and the risk of dental caries at age 3 years

BACKGROUND

Since birth outcome is associated with maternal and newborn health, it can be a predictor of the future health of the child.

AIM

To investigate the association between adverse birth outcomes and dental caries.

DESIGN

The present registry-based cohort study included all children born in 2000-2003, residing in Stockholm County, Sweden and who received a dental examination at the age of 3 years (n = 74 748). National registries supplied data on socioeconomic conditions, maternal health, maternal health behavior, and birth outcomes. Forward stepwise binary logistic regression was performed to determine predictors of caries experience in the 3-year-olds.

RESULTS

Of the subjects, 6.0% had caries experience (decayed, extracted, and filled teeth [deft] ≥ 1), 5.6% were born preterm (<37 weeks); 2.2% were born small (SGA) and 3.7% large (LGA) for gestational age. Of the studied adverse birth outcomes, only SGA was significantly associated with caries experience at 3 years of age, and only for mothers who had refrained from smoking during pregnancy.

CONCLUSIONS

SGA is associated with caries experience in 3-year-old children; however, this relationship occurs only in mothers who did not smoke during pregnancy.

First Trimester Microelements and their Relationships with Pregnancy Outcomes and Complications

Microelements involved in the oxidative balance have a significant impact on human health, but their role in pregnancy are poorly studied. We examined the relationships between first trimester levels of selenium (Se), iron (Fe), zinc (Zn), and copper (Cu), as well as maternal characteristics and pregnancy results. The data came from a Polish prospective cohort of women in a single pregnancy without chronic diseases. A group of 563 women who had a complete set of data, including serum microelements in the 10–14th week was examined, and the following were found: 47 deliveries <37th week; 48 cases of birth weight <10th and 64 newborns >90th percentile; 13 intrauterine growth restriction (IUGR) cases; 105 gestational hypertension (GH) and 15 preeclampsia (PE) cases; and 110 gestational diabetes mellitus (GDM) cases. The microelements were quantified using mass spectrometry. The average concentrations (and ranges) of the elements were as follows: Se: 60.75 µg/L (40.91–125.54); Zn: 618.50 µg/L (394.04–3238.90); Cu: 1735.91 µg/L (883.61–3956.76); and Fe: 1018.33 µg/L (217.55–2806.24). In the multivariate logistic regression, we found that an increase in Se of 1 µg/L reduces the risk of GH by 6% (AOR = 0.94; p = 0.004), the risk of IUGR by 11% (AOR = 0.89; p = 0.013), and the risk of birth <34th week by 7% (but close to the significance) (AOR = 0.93; p = 0.061). An increase in Fe of 100 µg/L reduces the risk of PE by 27% (AOR = 0.73; p = 0.009). In the multivariable linear regression, we found negative strong associations between prepregnancy BMI, Se (β = −0.130; p = 0.002), and Fe (β = −0.164; p < 0.0001), but positive associations with Cu (β = 0.320; p < 0.000001). The relationships between Se and maternal age (β = 0.167; p < 0.0001), Se and smoking (β = −0.106; p = 0.011) and Cu, and gestational age from the 10–14th week (β = 0.142; p < 0.001) were also found. Secondary education was associated with Zn (β = 0.132; p = 0.004) and higher education was associated with Cu (β = −0.102; p = 0.023). A higher financial status was associated with Fe (β = 0.195; p = 0.005). Other relationships were statistically insignificant. Further research is needed to clarify relationships between first trimester microelements and pregnancy complications. In addition, attention should be paid to lifestyle-related and socioeconomic factors that affect microelement levels.

Association of maternal prepregnancy weight and early childhood weight with obesity in adolescence: A population-based longitudinal cohort study in Japan

BACKGROUND

The impact of birth weight and obesity in early childhood on obesity in adolescence remains unclear.

OBJECTIVES

To examine the association of overweight/obesity at age 15 years with birth weight, overweight/obesity in early childhood and overweight/obesity in mothers.

METHODS

This population-based retrospective cohort study used early childhood and school age health check-up data of 1581 children in Japan, followed-up until age 15 years. Generalized estimation equation analyses were used to investigate the association of overweight/obesity at age 15 years with low/high birth weight, overweight/obesity in 3 years of age and overweight/obesity in mothers. The cutoff points for all variables were defined by international criteria.

RESULTS

Of 1581 mother-child pairs, 130 (8.2%) children had low birth weight, while 93 (5.9%) and 167 (10.6%) were overweight/obese at age 3 and 15 years, respectively. Overweight/obesity at age 3 years and overweight/obesity in mothers were associated with overweight/obesity at age 15 years (adjusted odds ratio [aOR], 4.26; 95% confidence interval [CI]: 2.51-7.25 and (aOR, 2.46; 95% CI: 1.41-4.30). No association between low birth weight and overweight/obesity at age 15 years was observed.

CONCLUSIONS

Overweight/obesity in mothers and overweight/obesity at 3 years of age, but not birth weight, were associated with overweight/obesity at age 15 years.

Secular trends of birthweight in boys from 1950 to 2010

BACKGROUND

Birthweight is an indicator of fetal development and intrauterine conditions and is associated with future health outcomes. Secular birthweight trends prior to the 1970s are mostly unknown. Our aim was to explore secular birthweight trends in Swedish boys from 1950 to 2010.

METHODS

We have collected detailed growth data including birthweight from archived School Health Care records for children born in Gothenburg from 1946 and onwards and established a unique population-based cohort, the Body Mass Index Epidemiology Study (BEST). The birthweight cohort spans six decades (1950-2010) and includes 46,548 boys.

RESULTS

The mean birthweight of the complete study cohort was 3580 ± 562 g. Linear regression analysis of the entire period revealed a minimal negative secular trend for birthweight (BETA = -0.4 g/year; p < 0.01). However, three distinct trends appeared during sub-periods: a decrease 1950-80, an increase 1980-2000 and another decrease 2000-2010.

CONCLUSION

We demonstrate that birthweight in boys has undergone periodic decreases and subsequent increases, but the overall trend from the 1950s to the present is stable.

Birthweight and risk of thyroid cancer and its histological types: A large cohort study

BACKGROUND

The aetiology of thyroid cancer is poorly understood, but it is possible that this malignancy has origins early in life. It is, however, currently unknown if birthweight, as an indicator of prenatal growth, is related to thyroid cancer risk.

OBJECTIVE

To investigate if birthweight is associated with the later risk of thyroid cancer and its histological types.

METHODS

246,141 children (120,505 girls, 125,636 boys) from the Copenhagen School Health Records Register, born 1936-1989, were prospectively followed in the Danish Cancer Registry. Cox regressions were used to estimate hazards ratios (HR) and 95% confidence intervals (CI).

RESULTS

During follow up, 241 individuals (172 women, 69 men) were diagnosed with thyroid cancer (162 papillary, 53 follicular). Birthweight was significantly and positively associated with risk of thyroid cancer overall (HR = 1.30 [95% CI: 1.03-1.64] per kilogram). There were no sex differences in the associations. Birthweight was positively and significantly associated with follicular thyroid cancer (HR = 1.74 [95% CI: 1.07-2.82] per kilogram), and although there was an indication of a positive association, it did not reach statistical significance for the more common papillary type (HR = 1.20 [95% CI: 0.90-1.59] per kilogram).

CONCLUSION

A heavier weight at birth is associated with an elevated risk of total and follicular thyroid cancer, which underscores that prenatal exposures may be important in thyroid cancer aetiology.

Epidemiology of childhood overweight, obesity and their related factors in a sample of preschool children from Central Iran

BACKGROUND

Childhood overweight and obesity are strongly associated with the psychological and physical health of those for the duration of the lifetime. The purpose of this study was to assess the epidemiology of childhood overweight and obesity and their related factors in Zarandieh city, of Iran, in 2017.

METHODS

In a cross-sectional study, 572 preschool-mother dyads from primary care Clinics were selected by multi-stage sampling method. BMI of the children and mothers were calculated using standard method and the demographic, children nutrition and physical activity habits; the mothers perceived threat toward obesity, and their life style data were collected by self-report questionnaires for the literate mothers and interviewing for illiterate mothers.

RESULT

The prevalence of overweight and obesity in mothers was 30.8 and 20.3% respectively. This rate in children was 15.5 and 9.9% respectively. The multiple logistic regression analysis showed that variables of mother's BMI, Birth weight, Mother's employment, watching TV > 2 h/day, Computer games> 2 h/day and daily breakfast eating (≥4/week), perceived threat, health responsibility, stress management, physical activity, and healthy eating were the significant predictors of the child's BMI respectively.

CONCLUSIONS

Our results indicated that the prevalence of overweight and obesity are high in preschool children and their mothers. It seems that necessary to have suitable intervention programs to help mothers understand the serious risk of childhood obesity and the importance of creating a healthy lifestyle by them in childhood.

Genetic and environmental factors affecting birth size variation: a pooled individual-based analysis of secular trends and global geographical differences using 26 twin cohorts

Background

The genetic architecture of birth size may differ geographically and over time. We examined differences in the genetic and environmental contributions to birthweight, length and ponderal index (PI) across geographical-cultural regions (Europe, North America and Australia, and East Asia) and across birth cohorts, and how gestational age modifies these effects.

Methods

Data from 26 twin cohorts in 16 countries including 57 613 monozygotic and dizygotic twin pairs were pooled. Genetic and environmental variations of birth size were estimated using genetic structural equation modelling.

Results

The variance of birthweight and length was predominantly explained by shared environmental factors, whereas the variance of PI was explained both by shared and unique environmental factors. Genetic variance contributing to birth size was small. Adjusting for gestational age decreased the proportions of shared environmental variance and increased the propositions of unique environmental variance. Genetic variance was similar in the geographical-cultural regions, but shared environmental variance was smaller in East Asia than in Europe and North America and Australia. The total variance and shared environmental variance of birth length and PI were greater from the birth cohort 1990-99 onwards compared with the birth cohorts from 1970-79 to 1980-89.

Conclusions

The contribution of genetic factors to birth size is smaller than that of shared environmental factors, which is partly explained by gestational age. Shared environmental variances of birth length and PI were greater in the latest birth cohorts and differed also across geographical-cultural regions. Shared environmental factors are important when explaining differences in the variation of birth size globally and over time.

Association between fetal macrosomia and risk of obesity in children under 3 years in Western China: a cohort study

BACKGROUND

Fetal macrosomia, defined as birth weight equal or over 4000 g, is a major concern for both neonatal and maternal health. A rapid increasing trend in fetal macrosomia is observed in different regions of China. We aimed to examine the association between fetal macrosomia and risk of childhood obesity in Western China.

METHODS

All macrosomic live singletons (≥ 4000 g), and a random sample of singletons with normal birth weight (2500-3999 g) born in four districts of Chengdu, Western China, in 2011 were included in the cohort study. Maternal demographics, obstetric factors, labor and delivery summary at baseline were extracted from the Chengdu Maternal and Child Health Management System. Anthropometric measurements before 3 years and infant feeding information at around 6 months were also collected. Childhood obesity under 3 years was primarily defined as a weight-for-length/height z score ≥ 1.645 using the WHO growth reference. Secondary definitions were based on weight-for-age and body mass index (BMI)-for-age over the same cut-offs.

RESULTS

A total of 1767 infants were included in the analyses, of whom 714 were macrosomic. After controlling for maternal age, parity, gestational age and anemia at the first antenatal visit, pre-pregnancy BMI, gestational weight gain, gestational age at birth, baby age and sex, and breastfeeding practices at 6 months, the risk of childhood obesity defined according to weight-for-length/height among macrosomic babies was 1.90 (95% confidence interval 1.04-3.49) times that of babies with normal birth weight. The risk of childhood obesity for macrosomic babies was 3.74 (1.96-7.14) and 1.64 (0.89-3.00) times higher based on weight-for-age and BMI-for-age, respectively.

CONCLUSION

Fetal macrosomia is associated with increased risk of obesity in children under 3 years in Western China.

The Protective Effect of Exclusive Breastfeeding on Overweight/Obesity in Children with High Birth Weight

BACKGROUND

A positive association between birth weight (BW) and body mass index (BMI) has been shown among children in many populations. The aim of this study was to investigate BMI trajectory according to BW status and the protective effect of breastfeeding on the prevalence of overweight/obesity in children 6 years of age.

METHODS

A retrospective cohort study was conducted between January 1, 2008 and December 31, 2016 utilizing data from the National Health Information Database of Korea. The 38,049 subjects were followed until the end of 2016, providing that subjects were completely eligible for all health check-ups from birth to 6 years of age. At each check-up period, multiple logistic regressions were used to investigate the association between BW status (low birth weight [LBW], normal birth weight [NBW], high birth weight [HBW]) and growth development.

RESULTS

HBW infants were highly likely to be overweight/obese compared to NBW infants (odds ratio [OR], 1.70-2.35) and LBW infants were highly likely to be underweight (OR, 1.69-2.20) through 6 years of age. The risk of overweight/obesity decreased significantly if HBW infants were breast-fed for 6 months (OR, 0.54-0.76).

CONCLUSION

HBW status is associated with overweight/obesity during early childhood. Exclusive breastfeeding is a significant protective factor against overweight/obesity in children with HBW.

Infant weight gain and adolescent body mass index: comparison across two British cohorts born in 1946 and 2001

OBJECTIVE

To investigate how the relationship of infant weight gain with adolescent body mass index (BMI) differs for individuals born during and before the obesity epidemic era.

DESIGN

Data from two British birth cohorts, the 1946 National Survey of Health and Development (NSHD, n=4199) and the 2001 Millennium Cohort Study (MCS, n=9417), were used to estimate and compare associations of infant weight gain between ages 0 and 3 years with adolescent outcomes.

MAIN OUTCOME MEASURES

BMI Z-scores and overweight/obesity at ages 11 and 14 years.

RESULTS

Infant weight gain, in Z-scores, was positively associated with adolescent BMI Z-scores in both cohorts. Non-linearity in the MCS meant that associations were only stronger than in the NSHD when infant weight gain was above -1 Z-score. Using decomposition analysis, between-cohort differences in association accounted for 20%-30% of the differences (secular increases) in BMI Z-scores, although the underlying estimates were not precise with 95% CIs crossing 0. Conversely, between-cohort differences in the distribution of infant weight gain accounted for approximately 9% of the differences (secular increases) in BMI Z-scores, and the underlying estimates were precise with 95% CI not crossing 0. Relative to normal weight gain (change of -0.67 to +0.67 Z-scores between ages 0 and 3 years), very rapid infant weight gain (>1.34), but not rapid weight gain (+0.67 to +1.34), was associated with higher BMI Z-scores more strongly in the MCS (β=0.790; 95% CI 0.717 to 0.862 at age 11 years) than in the NSHD (0.573; 0.466 to 0.681) (p<0.001 for between-cohort difference). The relationship of slow infant weight gain (<-0.67) with lower adolescent BMI was also stronger in the MCS. Very rapid or slow infant weight gain was not, however, more strongly associated with increased risk of adolescent overweight/obesity or thinness, respectively, in the more recently born cohort.

CONCLUSIONS

Greater infant weight gain, at the middle/upper end of the distribution, was more strongly associated with higher adolescent BMI among individuals born during (compared with before) the obesity epidemic. Combined with a secular change towards greater infant weight gain, these results suggest that there are likely to be associated negative consequences for population-level health and well-being in the future, unless effective interventions are developed and implemented.

Greater Breastfeeding in Early Infancy Is Associated with Slower Weight Gain among High Birth Weight Infants

OBJECTIVE

To examine whether feeding patterns from birth to age 6 months modify the association between birth weight and weight at 7-12 months of age.

STUDY DESIGN

Longitudinal mixed models were used to examine feeding trajectories across categories of birth weight and weight at 7-12 months of age in 1799 mother-infant dyads enrolled in the Infant Feeding Practices Study II. The percentage of breast milk received and the average daily formula consumption were calculated from birth to 6 months of age. Birth weights were classified as high (≥4000 g) and normal (≥2500 g and <4000 g). Weights at 7-12 months of age were categorized as high (z score >1) or normal (z score ≤1). A secondary analysis was performed using categories defined by birth weight adjusted for gestational age percentiles (>90% and 10th-90th percentile).

RESULTS

High birth weight (HBW) infants with high weights at 7-12 months of age demonstrated a rapid decline in the percentage of breast milk feedings compared with HBW infants with normal weights at 7-12 months of age. Normal birth weight infants with high weights at 7-12 months of age received a lower percentage of breast milk and had greater absolute intakes of formula than those with normal weights at 7-12 months of age; these associations did not vary over time. Results were similar when infants were categorized by birth weight percentiles.

CONCLUSIONS

A lower proportion of breast milk feedings was associated with excess weight at 7-12 months of age in HBW infants. These findings suggest an initial target for obesity prevention programs focusing on the first 6 months after birth.

The positive association of infant weight gain with adulthood body mass index has strengthened over time in the Fels Longitudinal Study

BACKGROUND

Infant weight gain is positively related to adulthood body mass index (BMI), but it is unknown whether or not this association is stronger for individuals born during (compared with before) the obesity epidemic.

OBJECTIVES

The aim of the study was to examine how the infant weight gain-adulthood BMI association might have changed across successive birth year cohorts spanning most of the 20th century.

METHODS

The sample comprised 346 participants in the Fels Longitudinal Study. Confounder-adjusted regression models were used to test the associations of conditional weight-for-length Z-score, capturing weight change between ages 0-2 years, with young adulthood BMI and blood pressure, including cohort [1933-1949 {N = 137}, 1950-1969 {N = 108}, 1970-1997 {N = 101}] as an effect modifier.

RESULTS

Conditional weight-for-length Z-score was positively related to adulthood BMI, but there was significant effect modification by birth year cohort such that the association was over two times stronger in the 1970-1997 cohort (β 2.31; 95% confidence interval 1.59, 3.03) compared with the 1933-1949 (0.98; 0.31, 1.65) and 1950-1969 (0.87; 0.21, 1.54) cohorts. A similar pattern was found for systolic blood pressure.

CONCLUSIONS

The infant weight gain-adulthood BMI association was over two times stronger among a cohort born during the obesity epidemic era compared with cohorts born earlier in the 20th century.

Exercise as a therapeutic intervention to optimize fetal weight

The Developmental Origins of Health and Disease suggest the in utero environment programs offspring obesity and cardiovascular disease. Therefore, there is a need to implement safe therapeutic interventions that do not involve the intake of medications or biological products during pregnancy that can improve maternal and fetal health. Prenatal exercise is established to promote maternal and fetal health. It is generally recommended that women accumulate at least 150 min per week of moderate-intensity exercise. It has been demonstrated that prenatal exercise maintains healthy weight gain and improves maternal glucose control, maternal cardiac autonomic control, placental efficiency (increases angiogenesis, downregulates genes involved in fatty acid transport and insulin transport across the placenta, and upregulates genes involved in amino acid transport across the placenta), and oxidative stress. These adaptations following exercise improve maternal metabolism and provide adequate uteroplacental perfusion. In this review, we will focus on exercise as a therapeutic intervention to optimize fetal weight. It has been established that prenatal exercise does not increase the risk of having a small for gestational age baby. To the contrary, prenatal exercise has been associated with the prevention of excessive fat accumulation in the newborn and the maintenance of fetal muscle mass.

Change in BMI Distribution over a 24-Year Period and Associated Socioeconomic Gradients: A Quantile Regression Analysis

OBJECTIVE

This study assessed the change in body mass index (BMI) distribution among 18- or 19-year-olds over 24 years. It also investigated parallel changes in the distribution of birth weight and in the association between birth weight and later risk of overweight and/or obesity. Parental educational variations in the trends and associations were explored.

METHODS

The study used data on 606,832 male military conscripts enlisted between 1985 and 2008. Quantile regression was used to assess the temporal change in BMI and birth weight distribution. The association between birth weight and overweight and/or obesity at age 18 or 19 years was quantified by using logistic regression.

RESULTS

Increases in BMI over time were found namely in the 90th, 95th, 97th, and 99th percentiles. Socioeconomic differences in this increase were documented in the 75th to 97th percentiles. The distribution of birth weight and the association between birth weight and the risk of overweight and/or obesity at age 18 or 19 years remained stable over time.

CONCLUSIONS

The difference in the increase in BMI between low and high percentiles indicates the limited role of mean BMI in reflecting population changes. The results suggest a need to focus on those with low socioeconomic position in the upper ends of the BMI distribution to combat increasing disparities in obesity-related outcomes.

Birth weight and the risk of histological subtypes of ovarian and endometrial cancers: Results from the Copenhagen School Health Records Register

BACKGROUND

Studies of birth weight associations with ovarian and endometrial cancer risks are limited with inconsistent results, and none has evaluated associations by histologic subtype. We utilized prospectively collected birth weight information to investigate the association with risk of ovarian and endometrial cancers overall and by histologic subtype.

METHODS

162,559 girls, born from 1930 to 1989, from the Copenhagen School Health Records Register (CSHRR) were followed prospectively via linkage with the Danish health registers. Ovarian (n=666) and endometrial (n=694) cancers were identified from 1978 to 2014. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Women with lower (2.0-3.25 vs. 3.26-3.75kg) and higher (3.75-5.5 vs. 3.26-3.75kg) birth weights had increased risks of ovarian cancer overall [HR (95% CI): 1.27 (1.06-1.52); 1.51 (1.21-1.87), respectively] and serous ovarian cancers [1.54 (1.19-1.98); 1.98 (1.47-2.67), respectively]. A decreased risk of Type II endometrial tumors was suggested per kilogram increase in birth weight [HR (95% CI): 0.63 (0.40-1.00)].

CONCLUSIONS

Our results suggest that both lower and higher birth weights were associated with increased ovarian cancer risk and associations were particularly strong for serous ovarian cancer, the most common subtype. Birth weight was not associated with most types of endometrial cancer.

Association between birthweight and later body mass index: an individual-based pooled analysis of 27 twin cohorts participating in the CODATwins project

Background

There is evidence that birthweight is positively associated with body mass index (BMI) in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment. We analysed the association between birthweight and BMI from infancy to adulthood within twin pairs, which provides insights into the role of genetic and environmental individual-specific factors.

Methods

This study is based on the data from 27 twin cohorts in 17 countries. The pooled data included 78 642 twin individuals (20 635 monozygotic and 18 686 same-sex dizygotic twin pairs) with information on birthweight and a total of 214 930 BMI measurements at ages ranging from 1 to 49 years. The association between birthweight and BMI was analysed at both the individual and within-pair levels using linear regression analyses.

Results

At the individual level, a 1-kg increase in birthweight was linearly associated with up to 0.9 kg/m2 higher BMI (P < 0.001). Within twin pairs, regression coefficients were generally greater (up to 1.2 kg/m2 per kg birthweight, P < 0.001) than those from the individual-level analyses. Intra-pair associations between birthweight and later BMI were similar in both zygosity groups and sexes and were lower in adulthood.

Conclusions

These findings indicate that environmental factors unique to each individual have an important role in the positive association between birthweight and later BMI, at least until young adulthood.

Effects of the Healthy Start randomized intervention on dietary intake among obesity-prone normal-weight children

OBJECTIVE

The study aimed to evaluate the impact of a 15-month intervention on dietary intake conducted among obesity-prone normal-weight pre-school children.

DESIGN

Information on dietary intake was obtained using a 4 d diet record. A diet quality index was adapted to assess how well children's diet complied with the Danish national guidelines. Linear regression per protocol and intention-to-treat analyses of differences in intakes of energy, macronutrients, fruit, vegetables, fish, sugar-sweetened beverages and diet quality index between the two groups were conducted.

SETTING

The Healthy Start study was conducted during 2009-2011, focusing on changing diet, physical activity, sleep and stress management to prevent excessive weight gain among Danish children.

SUBJECTS

From a population of 635 Danish pre-school children, who had a high birth weight (≥4000 g), high maternal pre-pregnancy BMI (≥28·0 kg/m2) or low maternal educational level (<10 years of schooling), 285 children completed the intervention and had complete information on dietary intake.

RESULTS

Children in the intervention group had a lower energy intake after the 15-month intervention (group means: 5·29 v. 5·59 MJ, P=0·02) compared with the control group. We observed lower intakes of carbohydrates and added sugar in the intervention group compared with the control group after the intervention (P=0·002, P=0·01).

CONCLUSIONS

The intervention resulted in a lower energy intake, particularly from carbohydrates and added sugar after 15 months of intervention, suggesting that dietary intake can be changed in a healthier direction in children predisposed to obesity.

Birth weight and subsequent body mass index in children: an international cross-sectional study

BACKGROUND

The reported association between birth weight and subsequent body mass index (BMI) is conflicting.

OBJECTIVES

To examine the relationship between birth weight and BMI in children aged 6-7 years.

METHODS

Secondary analysis of data from a multi-centre, multi-country, cross-sectional study (International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three). Parents/guardians of children aged 6-7 years completed questionnaires about their children's birth weight, current height and weight and whether their mother smoked in the first year of the child's life. A general linear mixed model was used to determine the association between BMI and birth weight.

RESULTS

A total of 72 111 children (17 countries) were included in the analysis. There was a positive association of birth weight with BMI (for each kg increase in birth weight the BMI at 6-7 increased by 0.47 (SE 0.02) kg/m² ; p < 0.0001) with a clear gradient by birth weight category. There was no statistically significant interaction between birth weight and Gross National Income (GNI).

CONCLUSIONS

There is a positive linear relationship between birth weight and BMI in 6-7 year old children, which is present in both high and low income countries.

No seasonality of birth in BMI at 7years of age

Seasonal variation in birth weight was found in a previous Danish study. In the present study we investigated if the seasonality in birth weight tracked into BMI at 7years of age, but found no seasonality of birth in either BMI, overweight, or obesity.

Pregnancy and childhood exposure to residential traffic noise and overweight at 7years of age

BACKGROUND

Exposure to road traffic noise has been associated with adiposity and diabetes in adults. The suggested pathways have been through sleep disturbance and stress. Children may be particularly susceptible to noise induced sleep disturbance and stress and the effects hereof.

OBJECTIVES

To examine the association between traffic noise exposure during pregnancy and early childhood and adiposity in children.

METHODS

We identified 40,974 singletons from the Danish National Birth Cohort with parentally given questionnaire information on weight and height at 7-years of age. Road and railway traffic noise were modeled at all historical addresses and expressed as time-weighted means for two exposure periods (pregnancy and childhood). Adiposity was assessed using BMI z-scores and a dichotomous measure of childhood overweight based on age and sex specific cut-offs. Associations were analyzed using linear regression for BMI z-scores and logistic regression for risk of childhood overweight, adjusting for socioeconomic position, maternal BMI, maternal smoking, maternal age, parity and degree of urbanization.

RESULTS

We found both pregnancy and childhood exposure to road traffic noise to be associated with a higher risk for childhood overweight (odds ratio (OR)=1.06 per 10dB, 95% confidence interval (CI): 1.00-1.12 for exposure during pregnancy and OR=1.06 per 10dB, 95% CI: 0.99-1.12 for childhood exposure). There were no associations between road traffic noise and BMI z-scores. We found no associations between railway noise and adiposity.

CONCLUSIONS

We found suggestions of a positive association between road traffic noise and risk of overweight in 7-years old children.

Prenatal, birth and early life predictors of sedentary behavior in young people: a systematic review

BACKGROUND

Our aim was to systematically summarize the evidence on whether prenatal, birth and early life factors up to 6 years of age predict sedentary behavior in young people (≤18 years).

METHODS

PRISMA guidelines were followed, and searches were conducted in PubMed, SPORTDiscus, EMBASE and Web of Science up to December 1, 2015. We included observational (non-intervention) and longitudinal studies, that reported data on the association between one or more of the potential predictors and objectively or subjectively measured sedentary behavior. Study quality was assessed using a formal checklist and data extraction was performed using standardized forms independently by two researchers.

RESULTS

More than 18,000 articles were screened, and 16 studies, examining 10 different predictors, were included. Study quality was variable (0.36-0.95). Two studies suggest that heritability and BMI in children aged 2-6 years were significant predictors of sedentary behavior later in life, while four and seven studies suggest no evidence for an association between gestational age, birth weight and sedentary behavior respectively. There was insufficient evidence whether other prenatal, birth and early life factors act as predictors of later sedentary behavior in young people.

CONCLUSION

The results suggest that heritability and early childhood BMI may predict sedentary behavior in young people. However, small number of studies included and methodological limitations, including subjective and poorly validated sedentary behavior assessment, limits the conclusions.

TRIAL REGISTRATION

The systematic review is registered in the International Prospective Register of Systematic Reviews, PROSPERO, 17.10.2014 ( CRD42014014156 ).

Associations between birth weight and colon and rectal cancer risk in adulthood

BACKGROUND

Birth weight has inconsistent associations with colorectal cancer, possibly due to different anatomic features of the colon versus the rectum. The aim of this study was to investigate the association between birth weight and colon and rectal cancers separately.

METHODS

193,306 children, born from 1936 to 1972, from the Copenhagen School Health Record Register were followed prospectively in Danish health registers. Colon and rectal cancer cases were defined using the International Classification of Disease version 10 (colon: C18.0-18.9, rectal: 19.9 and 20.9). Only cancers classified as adenocarcinomas were included in the analyses. Cox regressions were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Analyses were stratified by birth cohort and sex.

RESULTS

During 3.8 million person-years of follow-up, 1465 colon and 961 rectal adenocarcinomas were identified. No significant sex differences were observed; therefore combined results are presented. Birth weight was positively associated with colon cancers with a HR of 1.14 (95% CI, 1.04-1.26) per kilogram of birth weight. For rectal cancer a significant association was not observed for birth weights below 3.5kg. Above 3.5kg an inverse association was observed (at 4.5kg, HR=0.77 [95% CI, 0.61-0.96]). Further, the associations between birth weight and colon and rectal cancer differed significantly from each other (p=0.006).

CONCLUSIONS

Birth weight is positively associated with the risk of adult colon cancer, whereas the results for rectal cancer were inverse only above values of 3.5kg. The results underline the importance of investigating colon and rectal cancer as two different entities.

Risk Factors for Childhood Obesity in the First 1,000 Days: A Systematic Review

CONTEXT

Mounting evidence suggests that the origins of childhood obesity and related disparities can be found as early as the "first 1,000 days"-the period from conception to age 2 years. The main goal of this study is to systematically review existing evidence for modifiable childhood obesity risk factors present from conception to age 2 years.

EVIDENCE ACQUISITION

PubMed, Embase, and Web of Science were searched for studies published between January 1, 1980, and December 12, 2014, of childhood obesity risk factors present during the first 1,000 days. Prospective, original human subject, English-language research with exposure occurrence during the first 1,000 days and with the outcome of childhood overweight or obesity (BMI ≥85th percentile for age and sex) collected between age 6 months and 18 years were analyzed between December 13, 2014, and March 15, 2015.

EVIDENCE SYNTHESIS

Of 5,952 identified citations, 282 studies met inclusion criteria. Several risk factors during the first 1,000 days were consistently associated with later childhood obesity. These included higher maternal pre-pregnancy BMI, prenatal tobacco exposure, maternal excess gestational weight gain, high infant birth weight, and accelerated infant weight gain. Fewer studies also supported gestational diabetes, child care attendance, low strength of maternal-infant relationship, low SES, curtailed infant sleep, inappropriate bottle use, introduction of solid food intake before age 4 months, and infant antibiotic exposure as risk factors for childhood obesity.

CONCLUSIONS

Modifiable risk factors in the first 1,000 days can inform future research and policy priorities and intervention efforts to prevent childhood obesity.

Sex Differences in the Association Between Birth Weight and Adult Type 2 Diabetes

Low birth weight is a well-established risk factor for type 2 diabetes, but the risk at high birth weight levels remains uncertain. Potential sex differences in the associations are unexplored. We investigated whether sex influences the association of birth weight and adult type 2 diabetes, using a cohort of 113,801 men and 109,298 women, born 1936-1983, from the Copenhagen School Health Records Register, Denmark. During 5.6 million person-years of follow-up, 7,750 men and 4,736 women had a diagnosis of adult type 2 diabetes (30 years of age or older) obtained from national registers. When birth weights between 3.251 and 3.750 kg were used as the reference group for each sex separately, women with birth weights in the categories of 2.000 to 2.750 kg and 4.751 to 5.500 kg had hazard ratios [HRs] of type 2 diabetes of 1.46 (95% CI, 1.34-1.59) and 1.56 (1.20-2.04), respectively, whereas men had HRs of 1.20 (1.12-1.30) and 0.93 (0.76-1.15). Thus, sex modified the association, with stronger risk estimates of type 2 diabetes in women at both low and high birth weights compared with men (P = 0.001). In conclusion, birth weight is more strongly associated with type 2 diabetes in women than in men. Future search for sex-specific causal mechanisms may provide new insights into the early origins of type 2 diabetes.

Birth weight and childhood obesity: a 12-country study

OBJECTIVES

Few studies have investigated the association between the full range of birth weight and the risk of childhood obesity in high-, middle- and low-income countries. The aim of the present study is to assess the association between different levels of birth weight and the risk of obesity among children aged 9-11 years in 12 countries.

METHODS

A multinational, cross-sectional study of 5141 children aged 9-11 years was conducted in 12 countries. Height and weight were obtained using standardized methods. Time spent in moderate-to-vigorous physical activity (MVPA), sedentary and sleeping were objectively measured using 24-h, waist-worn accelerometer (Actigraph GT3X+) monitored for 7 days. Birth weight and other factors (regions, parental education, maternal history of gestational diabetes, children age, gender, breast feeding, gestational age, unhealthy diet scores and healthy diet scores) were collected by parental and children's questionnaires. Multilevel modeling was used to account for the nested nature of the data.

RESULTS

The overall prevalence of obesity (BMI z-score>+2 s.d.) was 15.4% for boys and 10.0% for girls. There was a positive association between birth weight and BMI z-scores. The multivariable-adjusted odds ratios (ORs) of childhood obesity were significantly higher among children whose birth weights were 3500-3999 g (OR 1.45; 95% confidence interval (CI): 1.10-1.92), and >4000 g (OR 2.08; 95% CI: 1.47-2.93), compared with the reference group (2500-2999 g). The positive association between birth weight and the odds of childhood obesity was seen in girls, whereas a U-shaped association appeared in boys.

CONCLUSIONS

High levels of birth weight, defined as birth weight ⩾3500 g, were associated with increased odds of obesity among 9-11-year-old children in 12 countries. However, sex differences in the association between birth weight and the risk of obesity need to be considered when planning interventions to reduce childhood obesity.

Obesity in children with brachial plexus birth palsy

Fetal macrosomia is associated with a 14-fold increased risk of brachial plexus birth palsy (BPBP), and is a predictor of childhood obesity. The purpose of this study was to identify the relationships between BPBP, fetal macrosomia, and childhood obesity. We retrospectively reviewed 214 children with BPBP. The average age was 8 years and 53% had a Narakas 1 grade BPBP. Overall, 49% of children were normal weight, 22% overweight, and 29% obese. Of the children with a history of fetal macrosomia, 41% were obese; a statistically significant difference. Overall quality of life scores, however, were not correlated with obesity.

Association between birth weight and objectively measured sedentary time is mediated by central adiposity: data in 10,793 youth from the International Children's Accelerometry Database

BACKGROUND

Birth weight is an early correlate of disease later in life, and animal studies suggest that low birth weight is associated with reduced activity and increased sedentary time. Whether birth weight predicts later sedentary time in humans is uncertain.

OBJECTIVES

We examined the relation between birth weight and sedentary time in youth and examined whether this association was mediated by central adiposity.

DESIGN

We used pooled cross-sectional data from 8 observational studies conducted between 1997 and 2007 that consisted of 10,793 youth (boys: 47%) aged 6-18 y from the International Children's Accelerometry Database. Birth weight was measured in hospitals or maternally reported, sedentary time was assessed by using accelerometry (<100 counts/min), and abdominal adiposity (waist circumference) was measured according to WHO procedures. A mediation analysis with bootstrapping was used to analyze data.

RESULTS

The mean (±SD) time spent sedentary was 370 ± 91 min/d. Birth weight was positively associated with sedentary time (B = 4.04, P = 0.006) and waist circumference (B = 1.59, P < 0.001), whereas waist circumference was positively associated with sedentary time (B = 0.82, P < 0.001). Results of the mediation analysis showed a significant indirect effect of birth weight on sedentary time through waist circumference (B: 1.30; 95% bias-corrected CI: 0.94, 1.72), and when waist circumference was controlled for, the effect of birth weight on sedentary time was attenuated by 32% (B = 2.74, P = 0.06).

CONCLUSION

The association between birth weight and sedentary time appears partially mediated by central adiposity, suggesting that both birth weight and abdominal adiposity may be correlates of sedentary time in youth.

Influence of early life factors on body mass index trajectory during childhood: a population-based longitudinal analysis in the Western Brazilian Amazon

Low- to middle-income countries may experience the occurrence of a dual burden of under and overnutrition. To better understand the overall progression of body mass index (BMI) during childhood, we estimated average BMI-for-age z-score (BAZ) growth curves in a population-based longitudinal study of 255 children living in the Brazilian Amazon. Children were aged 0.1-5.5 years at recruitment (2003). We collected data on socio-economic and maternal characteristics, children's birthweight and infant feeding practices. Child anthropometric measurements were taken in 2003, 2007 and 2009. BAZ differences among categories of exposure variables were calculated at 6 and 12 months, and 2, 7 and 10 years. At baseline, the mean (standard deviation) age was 2.6 (1.4) years; 12.9% were overweight and 3.9% thin. After adjustment, mean BAZ estimates were mostly negative. Boys were close to the median value for BAZ until 12 months, whereas girls were below the median (P=0.05). Children from households above the wealth median were 0.36 z- and 0.49 z-less underweight than poorer children at 7 and 10 years, respectively (P<0.01). Maternal BMI was positively associated with children's BAZ since 12 months old; BAZ in children from overweight mothers was higher by 0.69 compared with their counterparts at 10 years (P<0.01). Birthweight was positively related to BAZ up until 2 years (P=0.01). Socio-economic background and maternal nutritional status are important predictors of BAZ throughout childhood. Although excessive weight gain is a public health concern, it is critical to restrict inequities, while promoting healthier growth in developing countries.

Accuracy and reproducibility of adipose tissue measurements in young infants by whole body magnetic resonance imaging

PURPOSE

MR might be well suited to obtain reproducible and accurate measures of fat tissues in infants. This study evaluates MR-measurements of adipose tissue in young infants in vitro and in vivo.

MATERIAL AND METHODS

MR images of ten phantoms simulating subcutaneous fat of an infant's torso were obtained using a 1.5T MR scanner with and without simulated breathing. Scans consisted of a cartesian water-suppression turbo spin echo (wsTSE) sequence, and a PROPELLER wsTSE sequence. Fat volume was quantified directly and by MR imaging using k-means clustering and threshold-based segmentation procedures to calculate accuracy in vitro. Whole body MR was obtained in sleeping young infants (average age 67±30 days). This study was approved by the local review board. All parents gave written informed consent. To obtain reproducibility in vivo, cartesian and PROPELLER wsTSE sequences were repeated in seven and four young infants, respectively. Overall, 21 repetitions were performed for the cartesian sequence and 13 repetitions for the PROPELLER sequence.

RESULTS

In vitro accuracy errors depended on the chosen segmentation procedure, ranging from 5.4% to 76%, while the sequence showed no significant influence. Artificial breathing increased the minimal accuracy error to 9.1%. In vivo reproducibility errors for total fat volume of the sleeping infants ranged from 2.6% to 3.4%. Neither segmentation nor sequence significantly influenced reproducibility.

CONCLUSION

With both cartesian and PROPELLER sequences an accurate and reproducible measure of body fat was achieved. Adequate segmentation was mandatory for high accuracy.

Relationship between birth weight and overweight/obesity among students in Florianópolis, Santa Catarina, Brazil: a retrospective cohort study

CONTEXT AND OBJECTIVE

Being born heavier than 4 kg is associated with current overweight and obesity over the long term. The objective here was to ascertain whether birth weight was related to overweight or obese status, among 7 to 14-year-old schoolchildren, taking into consideration the possible interactions between socioeconomic factors and other biological variables.

DESIGN AND SETTING

Retrospective cohort study on a probabilistic sample of 2,696 children and adolescents living in Florianópolis, Santa Catarina, Brazil.

METHODS

The following data were collected: anthropometric (student's weight, height and age; and parents' weight and height), socioeconomic (family income, number of people in house and parental schooling level), birth weight and gestational age. Overweight and obesity were classified using percentiles of body mass index and triceps and subscapular skinfolds. The outcome variables were overweight and obesity and the main explanatory variables were birth weight and birth weight according to gestational age. The control variables were the parents' nutritional status, their schooling level and the per capita family income. Poisson multivariate regressions were carried out.

RESULTS

Higher prevalence of high birth weight was observed among overweight male adolescents (PR = 1.14; 95% CI = 1.02-1.27; P = 0.03), but this was not observed among obese male adolescents. Low birth weight and being born small for gestational age were also not associated with the outcomes. Among overweight and obese children, birth weight was not significantly different from that of normal-weight children.

CONCLUSION

No significant association between birth weight and obesity was observed. However, there was a weak but significant association between high birth weight and overweight, among male adolescents.

Neonatal anthropometrics and body composition in obese children investigated by dual energy X-ray absorptiometry

Epidemiological and animal studies have suggested an effect of the intrauterine milieu upon the development of childhood obesity. This study investigates the relationship between body composition measured by dual energy X-ray absorptiometry expressed as body fat percent, body fat mass index (BFMI), and fat free mass index (FFMI) in obese children and the preceding in utero conditions expressed by birth weight, birth length, and birth weight for gestational age. The study cohort consisted of 776 obese Danish children (median age 11.6 years, range 3.6-17.9) with a mean Body Mass Index Standard Deviation Score (BMI SDS) of 2.86 (range 1.64-5.48) treated in our national referral centre. In a linear general regression model adjusted for age, gender, socioeconomic status, and duration of breastfeeding, we found the body fat percent, FFMI, and BFMI at the time of enrolment in childhood obesity treatment to be significantly correlated with both birth weight and birth weight for gestational age.

CONCLUSION

These results indicate a prenatal influence upon childhood obesity. Although there are currently no sufficient data to suggest any recommendations to pregnant women, it is possible that the prenatal period may be considered as a potential window of opportunity for prevention of childhood overweight and obesity.

Stability of the associations between early life risk indicators and adolescent overweight over the evolving obesity epidemic

Background

Pre- and perinatal factors and preschool body size may help identify children developing overweight, but these factors might have changed during the development of the obesity epidemic.

Objective

We aimed to assess the associations between early life risk indicators and overweight at the age of 9 and 15 years at different stages of the obesity epidemic.

Methods

We used two population-based Northern Finland Birth Cohorts including 4111 children born in 1966 (NFBC1966) and 5414 children born in 1985–1986 (NFBC1986). In both cohorts, we used the same a priori defined prenatal factors, maternal body mass index (BMI), birth weight, infant weight (age 5 months and 1 year), and preschool BMI (age 2–5 years). We used internal references in early childhood to define percentiles of body size (<50, 50–75, 75–90 and >90) and generalized linear models to study the association with overweight, according to the International Obesity Taskforce (IOTF) definitions, at the ages of 9 and 15 years.

Results

The prevalence of overweight at the age of 15 was 9% for children born in 1966 and 16% for children born in 1986. However, medians of infant weight and preschool BMI changed little between the cohorts, and we found similar associations between maternal BMI, infant weight, preschool BMI, and later overweight in the two cohorts. At 5 years, children above the 90^th percentile had approximately a 12 times higher risk of being overweight at the age of 15 years compared to children below the 50^th percentile in both cohorts.

Conclusions

The associations between early body size and adolescent overweight showed remarkable stability, despite the increase in prevalence of overweight over the 20 years between the cohorts. Using consequently defined internal percentiles may be a valuable tool in clinical practice.

Prevalence of overweight and obesity among 6-to 9-year-old school children in Cuenca, Ecuador: relationship with physical activity, poverty, and eating habits

BACKGROUND

The high prevalence of childhood overweight and obesity is a health problem worldwide. In developing countries, we lack information on the extent of the problem and the risk factors involved.

OBJECTIVE

To determine the prevalence rates of overweight and obesity and of abdominal obesity, and their relationship with physical activity, poverty, and eating habits in schoolchildren in Cuenca, Ecuador.

METHODS

A cross-sectional survey in a representative sample (n = 743) schoolchildren aged 6 to 9 years was conducted. Overweight and obesity were detected using the International Obesity Task Force cutoffs according to body mass index (BMI), and abdominal obesity was detected according to waist circumference. Poverty, physical activity, and eating habits were assessed with validated questionnaires.

RESULTS

The prevalence rates of overweight and obesity and of abdominal obesity were 26.0% and 10.6%, respectively. There were no differences between the sexes, but the prevalence of overweight and obesity was 1.5- to 2-fold higher in 9-year-old than in 6-year-old children (p < .05). Multivariate models demonstrated that higher BMI and waist circumference were significantly related to low physical activity and nonpoverty. Insufficient physical activity (in 75% of children) was associated with a 13% to 18% increased risk of overweight and obesity and abdominal obesity. Eating breakfast and eating more than three meals per day (in 96.7% and 85.9% of children, respectively) were not related to the prevalence of overweight and obesity. Eating fruits during school break was associated with a lower BMI.L CONCLUSIONS: The high prevalence of overweight and obesity observed in schoolchildren increased from the ages of 6 to 9 years and was associated with insufficient physical activity and nonpoverty. Promoting physical activity and fruit consumption in school snacks should be explored as intervention measures to prevent and reduce overweight and obesity in Cuenca schoolchildren.