Relation between weight and length at birth and body mass index in young adulthood: cohort study

Neurodevelopmental Programming of Adiposity: Contributions to Obesity Risk

This review analyzes the published evidence regarding maternal factors that influence the developmental programming of long-term adiposity in humans and animals via the central nervous system (CNS). We describe the physiological outcomes of perinatal underfeeding and overfeeding and explore potential mechanisms that may mediate the impact of such exposures on the development of feeding circuits within the CNS-including the influences of metabolic hormones and epigenetic changes. The perinatal environment, reflective of maternal nutritional status, contributes to the programming of offspring adiposity. The in utero and early postnatal periods represent critically sensitive developmental windows during which the hormonal and metabolic milieu affects the maturation of the hypothalamus. Maternal hyperglycemia is associated with increased transfer of glucose to the fetus driving fetal hyperinsulinemia. Elevated fetal insulin causes increased adiposity and consequently higher fetal circulating leptin concentration. Mechanistic studies in animal models indicate important roles of leptin and insulin in central and peripheral programming of adiposity, and suggest that optimal concentrations of these hormones are critical during early life. Additionally, the environmental milieu during development may be conveyed to progeny through epigenetic marks and these can potentially be vertically transmitted to subsequent generations. Thus, nutritional and metabolic/endocrine signals during perinatal development can have lifelong (and possibly multigenerational) impacts on offspring body weight regulation.

Intensive glycaemic targets in overweight and obese individuals with gestational diabetes mellitus: clinical trial protocol for the iGDM study

INTRODUCTION

The prevalence of both obesity and gestational diabetes mellitus (GDM) has increased, and each is associated with adverse perinatal outcomes including fetal overgrowth, neonatal morbidity, hypertensive disorders of pregnancy and caesarean delivery. Women with GDM who are also overweight or obese have higher rates of pregnancy complications when compared with normal-weight women with GDM, which may occur in part due to suboptimal glycaemic control. The current recommendations for glycaemic targets in pregnant women with diabetes are based on limited evidence and exceed the mean fasting (70.9±7.8 mg/dL) and 1-hour postprandial (108.9±12.9 mg/dL) glucose values in pregnant individuals without diabetes. Our prior work demonstrated that the use of intensive (fasting <90 mg/dL and 1-hour postprandial <120 mg/dL) compared with standard (fasting <95 mg/dL and 1-hour postprandial <140 mg/dL) glycaemic targets resulted in improved glycaemic control without increasing the risk for hypoglycaemia in pregnant individuals with GDM, but the impact of intensive glycaemic targets on perinatal outcomes is unknown.

METHODS AND ANALYSIS

The Intensive Glycemic Targets in Overweight and Obese Women with Gestational Diabetes Mellitus: A Multicenter Randomized Trial (iGDM Trial) is a large, pragmatic randomised clinical trial designed to investigate the impact of intensive versus standard glycaemic targets on perinatal outcomes in women with GDM who are overweight and obese. During the 5-year project period, a multidisciplinary team of investigators from five medical centres representing regions of the USA with high rates of obesity will randomise 828 overweight and obese women with GDM to either intensive or standard glycaemic targets. We will test the central hypothesis that intensive glycaemic targets will result in lower rates of neonatal composite morbidity including large for gestational age birth weight, neonatal hypoglycaemia, respiratory distress syndrome and need for phototherapy when compared with standard glycaemic targets using the intention-to-treat approach to analysis.

ETHICS AND DISSEMINATION

The Institutional Review Board (IRB) at Indiana University School of Medicine approved this study (IRB# 11435; initial approval date 25 August 2021). We will submit the results of the trial for publication in peer-reviewed journals and presentations at international scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05124808.

Causal effects of time-varying body size on selected autoimmune disorders: a life course Mendelian randomisation study

BACKGROUND

Based on Barker's hypothesis, some studies investigated the associations between birth weight and several disorders. Apart from issues with statistical power and well-known shortcomings of the observational study design, there are no studies accounting for changes in weight-related body size over the life course regarding rheumatoid arthritis, psoriasis, psoriatic arthritis and multiple sclerosis.

METHODS

Using genetic information of up to 806 834 participants, this study investigated the associations between time-varying weight-related body size from birth to adulthood and the mentioned autoimmune diseases. Performing Mendelian randomisation (MR), the radial inverse-variance weighted approach was used iteratively in primary analyses. Robustness of the results was confirmed in several sensitivity analyses. Potential time-dependent mediation mechanisms were identified through network-clustering and assessed using multivariable MR.

RESULTS

Genetically predicted birth weight (fetal effect) was positively associated with rheumatoid arthritis (OR 1.44; 95% CI 1.17 to 1.77; Padj =0.005) but not with psoriasis, psoriatic arthritis or multiple sclerosis. This association was found to be mediated by body mass index (BMI) in adulthood (OR 1.45; 95% CI 1.14 to 1.84; Padj =0.019) rather than childhood. The direct effect of birth weight attenuated (OR 1.19; 95% CI 0.88 to 1.62); Padj =1) after adjustment for time-varying BMI.

CONCLUSION

Increased birth weight appears to be a risk factor for later manifestation of rheumatoid arthritis due to both fetal genetic components and high BMI persisting into adulthood. Approaches to prevent and minimise the risk of rheumatoid arthritis could include preventing obesity in adults with high birth weight.

Maternal triglyceride levels and neonatal outcomes: The Japan Environment and Children's Study

BACKGROUND

Although maternal triglyceride (TG) is important for fetal growth, there are few large cohort studies investigating the relationships between maternal TG during pregnancy and neonatal outcomes.

OBJECTIVES

The objective of this study was to investigate the associations between maternal TG during the second and third trimesters and neonatal outcomes including preterm birth (PTB), low birth weight (LBW), small for gestational age (SGA) and large for gestational age (LGA).

METHODS

This was a prospective birth cohort study using data of the Japan Environment and Children's Study included data of births from 2011-2014 in Japan including 79,519 pairs. Participants were divided into tertiles according to maternal TG in the second or third trimesters. Multiple logistic regression modeling was used to examine the risks of LBW, SGA, LGA and PTB in association with maternal TG levels in the second or third trimesters RESULTS: In the second trimester, compared with reference TG group (T2), women in higher TG group (T3) and lower TG group (T1) were also at increased risk of LGA (aOR 1.20, 95% CI 1.11-1.29) and SGA (aOR 1.25, 95% CI 1.10-1.41), respectively. In the third trimester, women in T3 and T1 were at increased risk of LGA (aOR 1.27, 95% CI 1.17-1.38) and SGA (aOR 1.17, 95% CI 1.02-1.34), respectively.

CONCLUSION

In this study, higher maternal TG levels in the second or third trimesters were associated with risks of LGA, however, lower maternal TG levels in the second or third trimesters were conversely associated with risks of SGA.

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.

Secular trends of birth weight and its associations with obesity and hypertension among Southern Chinese children and adolescents

OBJECTIVES

The association of low or high birth weight (L/HBW) with obesity and hypertension in childhood remains unclear. We aimed to identify the secular trend of birth weight distribution and its relationship to obesity and hypertension in Southern Chinese children and adolescents.

METHODS

6,561 individuals (6-17-year-old) were enrolled by multistage cluster sampling to observed the trend of birth weight distribution and its associated factors. 1,218 were further selected by group matching to investigate the correlation between birth weight and obesity or hypertension.

RESULTS

Between 1997 and 2008, a significant decline in the LBW rate and no significant change in the HBW rate was found. LBW was associated with maternal BMI<18 kg/m² (OR1.79, 95% CI 1.08-2.97) during pregnancy, while maternal BMI between 25.0 and 27.9 kg/m² (OR1.62, 95% CI 1.04-2.52) and paternal BMI>28 kg/m² (OR1.64, 95% CI 1.02-2.63) during pregnancy were associated with HBW. The prevalence of obesity was significantly higher with HBW than normal birth weight (NBW) or LBW (16.73, 6.25 and 5.50%, respectively). The prevalence rates of suspected hypertension were 1.62, 1.25 and 1.49% among LBW, NBW and HBW, respectively (p>0.05). LBW decreased the risks of childhood overweight (OR0.31, 95% CI 0.18-0.54), but had no effect on suspected hypertension. HBW increased the risks of childhood obesity (OR2.19, 95% CI 1.50-3.20), but decreased the risks of suspected hypertension (OR0.22, 95% CI 0.09-0.58).

CONCLUSIONS

HBW was positively associated with childhood obesity, and parental BMIs management might be one of the measurements to control birth weight to lessen childhood obesity.

The Combined Effect of Birth Weight and Lifestyle on Clustered Cardio-Metabolic Risk Factors in Children and Adolescents: A National School-Based Cross-Sectional Survey

Background: Due to the adverse effects of cardio-metabolic risk factors (CMRFs) in children and adolescents on their current and later life health, and the growing evidence that birth weight and lifestyle have on CMRFs, we aimed to estimate the combined effect of birth weight and lifestyle on clustered CMRFs in children and adolescents. Methods: We enrolled 11,509 participants aged 7–18 years old in a national school-based cross-sectional study in seven provinces in China in 2013. Information on CMRFs was collected through anthropometric measurements and blood sample testing. Information on birth weight, lifestyle and other basic information were investigated through children and adolescents’ as well as parents’ questionnaires. The generalized linear mixed model was applied to estimate the odd ratio (OR) and 95% confidence interval (95% CI) for the associations between CMRFs, clustered CMRFs and birth weight, lifestyle, and the combinations of birth weight and lifestyle. Results: Overall, the prevalence of clustered CMRFs was 3.6% in children and adolescents aged 7–18 years, higher in boys (4.4%) than girls (2.9%). The combination of LBW/ideal lifestyle (OR = 2.00, 95% CI: 1.07–3.72) was associated with higher risk of clustered CMRFs, as well as in adolescents aged 13–18 years and in boys. The combination of HBW/poor lifestyle (OR = 1.74, 95% CI: 1.13–2.68) was related to elevated risk of clustered CMRFs, especially in children aged 7–12 years. Conclusions: CMRFs in Chinese children and adolescents is concerning, ideal lifestyle could weaken the association of birth weight with clustered CMRFs, especially in younger age, indicating that programs to prevent abnormal birth weight or poor lifestyle or both among children and adolescents may reduce CMRFs in China.

Fetal alleles predisposing to metabolically favorable adiposity are associated with higher birth weight

BACKGROUND

Higher birthweight is associated with higher adult body mass index (BMI). Alleles that predispose to greater adult adiposity might act in fetal life to increase fetal growth and birthweight. Whether there are fetal effects of recently identified adult metabolically favorable adiposity alleles on birthweight is unknown.

AIM

We aimed to test the effect on birthweight of fetal genetic predisposition to higher metabolically favorable adult adiposity and compare that with the effect of fetal genetic predisposition to higher adult BMI.

METHODS

We used published genome wide association study data (n = upto 406 063) to estimate fetal effects on birthweight (adjusting for maternal genotype) of alleles known to raise metabolically favorable adult adiposity or BMI. We combined summary data across single nucleotide polymorphisms (SNPs) with random effects meta-analyses. We performed weighted linear regression of SNP-birthweight effects against SNP-adult adiposity effects to test for a dose-dependent association.

RESULTS

Fetal genetic predisposition to higher metabolically favorable adult adiposity and higher adult BMI were both associated with higher birthweight (3 g per effect allele (95% CI: 1-5) averaged over 14 SNPs; P = 0.002; 0.5 g per effect allele (95% CI: 0-1) averaged over 76 SNPs; P = 0.042, respectively). SNPs with greater effects on metabolically favorable adiposity tended to have greater effects on birthweight (R2 = 0.2912, P = 0.027). There was no dose-dependent association for BMI (R2 = -0.0019, P = 0.602).

CONCLUSIONS

Fetal genetic predisposition to both higher adult metabolically favorable adiposity and BMI is associated with birthweight. Fetal effects of metabolically favorable adiposity-raising alleles on birthweight are modestly proportional to their effects on future adiposity, but those of BMI-raising alleles are not.

Short- and Long-Term Outcomes Associated with Large for Gestational Age Birth Weight

Large for gestational age birth weight is associated with adverse short- and long-term outcomes. Infants born with large for gestational age birth weight are at increased risk for neonatal intensive care unit admission, respiratory distress, neonatal metabolic abnormalities including hypoglycemia, birth trauma, and even stillbirth or neonatal death. The risk for many of these complications increases with higher birth weights. Individuals with large for gestational age birth weight also appear to be at subsequent increased risk for overweight/obesity, diabetes, cardiovascular disease, and even some childhood cancers. These data highlight the need for effective interventions to decrease risk across the lifespan.

Genetic Meta-Analysis of Twin Birth Weight Shows High Genetic Correlation with Singleton Birth Weight

Birth weight (BW) is an important predictor of newborn survival and health and has associations with many adult health outcomes, including cardio-metabolic disorders, autoimmune diseases, and mental health. On average, twins have a lower BW than singletons as a result of a different pattern of fetal growth and shorter gestational duration. Therefore, investigations into the genetics of BW often exclude data from twins, leading to a reduction in sample size and remaining ambiguities concerning the genetic contribution to BW in twins. In this study, we carried out a genome-wide association meta-analysis of BW in 42 212 twin individuals and found a positive correlation of beta values (Pearson's r = 0.66, 95% confidence interval [CI]: 0.47-0.77) with 150 previously reported genome-wide significant variants for singleton BW. We identified strong positive genetic correlations between BW in twins and numerous anthropometric traits, most notably with BW in singletons (genetic correlation [rg] = 0.92, 95% CI: 0.66-1.18). Genetic correlations of BW in twins with a series of health-related traits closely resembled those previously observed for BW in singletons. Polygenic scores constructed from a genome-wide association study on BW in UK Biobank demonstrated strong predictive power in a target sample of Dutch twins and singletons. Together, our results indicate that a similar genetic architecture underlies BW in twins and singletons and that future genome-wide studies might benefit from including data from large twin registers.

Diabesity and Pregnancy: How Do We Get Our Patients Moving?

Obesity and diabetes are 2 commonly encountered complications in pregnancy that adversely affect pregnancy outcomes, maternal health, and the health of the offspring, both short-term and long-term. It is well established that physical activity provides numerous health benefits, both during and outside of pregnancy. By participating in physical activity, many of the negative consequences of both obesity and diabetes may be mitigated. Physical activity guidelines recommend that all adults, including pregnant women, perform at least 150 minutes of moderate-intensity exercise weekly in order to obtain health benefits. More physical activity may be needed to achieve weight management goals.

Association between false positive glucose challenge test results and large-for-gestational-age infants: a retrospective cohort study

OBJECTIVES

There is no consensus regarding a possible relation between false positive glucose challenge test (GCT) results and large-for-gestational-age (LGA) infants. This study aimed to clarify the association between false positive GCT results and LGA, after adjusting for potential confounding factors, using a large clinical dataset.

DESIGN

Retrospective cohort study.

SETTING

National Hospital Organisation Kofu National Hospital, which is a community hospital, between January 2012 and August 2019.

PARTICIPANTS

Japanese women who underwent GCT between 24 and 28 weeks of gestation at the hospital were included. After excluding those with gestational diabetes mellitus, diabetes in pregnancy and multiple pregnancies, subjects were divided into a false positive GCT group (≥140 mg/dL) and a GCT negative group (<140 mg/dL).

METHODS

Obstetric records of patients were examined. The χ²-test and multivariable logistic regression analysis were used to investigate the association between false positive GCT results and LGA.

PRIMARY AND SECONDARY OUTCOME MEASURES

Incidence of LGA and the association between false positive GCT results and LGA.

RESULTS

The mean subject age was 31.4±5.5 years, with 43.3% nulliparity (n=974) and 2160 (96.1%) term deliveries. The incidence of LGA was 9.4% (211/2248) and 11.4% (257/2248) of the women had false positive GCT results. False positive GCT results were significantly associated with an increased risk of LGA (OR, 1.51; 95% CI, 1.02 to 2.23), after controlling for maternal age, prepregnancy maternal weight, maternal weight gain during pregnancy and parity.

CONCLUSIONS

It appears that there is a significant association between false positive GCT results and LGA. Additional research is required to confirm these results and to investigate appropriate interventions for women with abnormal screens for gestational diabetes mellitus.

Large-for-gestational-age phenotypes and obesity risk in adulthood: a study of 195,936 women

While there is evidence that being born large-for-gestational-age (LGA) is associated with an increased risk of obesity later in life, the data are conflicting. Thus, we aimed to examine the associations between proportionality at birth and later obesity risk in adulthood. This was a retrospective study using data recorded in the Swedish Birth Register. Anthropometry in adulthood was assessed in 195,936 pregnant women at 10-12 weeks of gestation. All women were born at term (37-41 weeks of gestation). LGA was defined as birth weight and/or length ≥2.0 SDS. Women were separated into four groups: appropriate-for-gestational-age according to both weight and length (AGA - reference group; n = 183,662), LGA by weight only (n = 4,026), LGA by length only (n = 5,465), and LGA by both weight and length (n = 2,783). Women born LGA based on length, weight, or both had BMI 0.12, 1.16, and 1.08 kg/m² greater than women born AGA, respectively. The adjusted relative risk (aRR) of obesity was 1.50 times higher for those born LGA by weight and 1.51 times for LGA by both weight and height. Length at birth was not associated with obesity risk. Similarly, women born LGA by ponderal index had BMI 1.0 kg/m² greater and an aRR of obesity 1.39 times higher than those born AGA. Swedish women born LGA by weight or ponderal index had an increased risk of obesity in adulthood, irrespective of their birth length. Thus, increased risk of adult obesity seems to be identifiable from birth weight and ignoring proportionality.

Excessive Maternal Weight and Diabetes Are Risk Factors for Macrosomia: A Cross-Sectional Study of 42,663 Pregnancies in Uruguay

OBJECTIVE

To evaluate the risk of macrosomia in newborns from women with gestational diabetes, pregestational diabetes, overweight, and obesity in Uruguay in 2012, as well as its association with prolonged pregnancy, maternal age, multiparity, and excessive gestational weight gain (EGWG).

METHODS

We performed a cross-sectional study of 42,663 pregnant women. The risk of macrosomia was studied using logistic regression.

RESULTS

Mean maternal age was 26.7 ± 6.8 years. Pregestational overweight and obesity was present in 20.9% and 10.7% of women, respectively. There were 28.1% and 19.8% of women overweight and obese at the end of the pregnancy, respectively. Furthermore, 0.5% had pregestational diabetes and 8.5% were multiparous. Twenty two percent developed gestational diabetes and 44.9% had EGWG. The prevalence of macrosomia was 7.9%, significantly more prevalent in males (10.0% vs. 5.5%, p<0.005). Univariate analysis showed that obesity and overweight pre-pregnancy, obesity and overweight at the end of pregnancy, EGWG, pregestational diabetes, gestational diabetes, multiparity, prolonged pregnancy, and male newborn were strongly associated with macrosomia (p<0.0001). Maternal age >35 years did not increase the risk of macrosomia. After multiple logistic regression macrosomia was more likely in pre-gestational obese women (OR 1.24; CI 1.07-1.44), overweight women at the end of pregnancy (OR 1.66; CI 1.46-1.87), obese women at the end of pregnancy (OR 2.21; CI 1.90-2.58), women with EGWG (OR 1.78; CI 1.59-1.98), pregestational diabetes (OR 1.75; CI 1.15-2.69), gestational diabetes (OR 1.39; CI 1.25-1.53), prolonged pregnancy (OR 2.67; CI 2.28-3.12), multiparity (OR 1.24; CI 1.04-1.48), and male newborn (OR 1.89; CI 1.72-2.08).

CONCLUSION

Maternal overweight, obesity, EGWG, and gestational diabetes are prevalent in Uruguay, increasing the risk of macrosomia. Efforts to implement strategies to decrease the prevalence of overweight and obesity among women of reproductive age are essential to improve maternal and neonatal outcomes.

Cord blood fatty acid-binding protein-4 levels are upregulated at both ends of the birthweight spectrum

AIM

Fatty acid-binding protein-4 (FABP4) is an adipokine associated with obesity and signs of the metabolic syndrome. We aimed to investigate at birth in term neonates with normal and abnormal intrauterine growth concentrations of FABP4 and associate them with various perinatal parameters.

METHODS

Serum cord blood FABP4 levels were prospectively determined by ELISA in 80 singleton term appropriate-for-gestational-age (AGA), intrauterine growth-restricted (IUGR) and large-for-gestational-age (LGA) neonates.

RESULTS

Compared to the AGA group, cord blood FABP4 levels were increased in the IUGR and LGA groups. Additionally, they were higher in early-term than full-term neonates. A significant U-shaped correlation was recorded between serum FABP4 levels and birthweight. A significant negative correlation between cord blood FABP4 and gestational age in the whole study population was noted.

CONCLUSION

Cord blood FABP4 levels were significantly higher at the extremes of foetal growth at term and negatively correlated with gestational age, being increased in early-term versus full-term neonates. Further longitudinal studies with larger sample sizes are required to elucidate FABP4 implication in foetal growth and its association with future adverse cardiometabolic outcomes in the offspring.

Gestational Weight Gain Particularly Affects the Risk of Large for Gestational Age Infants in Non-obese Mothers

Introduction The birth of a large for gestational age (LGA) infant is a significant risk factor for birth complications and maternal morbidity and an even higher risk factor for offspring obesity, metabolic syndrome and cardiovascular disease in later life. Relevant factors affecting the risk of delivering an LGA infant are maternal pre-gravid obesity, excessive gestational weight gain exceeding the recommendations of the Institute of Medicine (IOM) and diabetes in pregnancy. We aimed to determine what matters most in terms of the risk of fetal overgrowth.

Materials and Methods We performed a database analysis of 12 701 singleton term deliveries documented in our university hospital birth registry from 2003 to 2014. Multivariate logistic regression analysis was used to determine the adjusted odds ratios.

Results Excessive weight gain had the strongest impact on LGA (OR: 1.249 [95% CI: 1.018 – 1.533]) compared to maternal pre-gravid body mass index (BMI) (OR: 1.083 [95% CI: 1.066 – 1.099]) and diabetes (OR: 1.315 [95% CI: 0.997 – 1.734]). Keeping gestational weight gain within the recommendations of the IOM resulted in a risk reduction for LGA of 20% (OR: 0.801 [95% CI: 0.652 – 0.982]). The risk for LGA increases by 6.9% with each kg weight gain. Normal weight women (BMI 18.5 – 24.9 kg/m ² ) and moderately overweight women (BMI 25 – 29.9 kg/m ² ) showed the highest increase in LGA rates per kg weight gain during pregnancy (OR: 1.078 [95% CI: 1.052 – 1.104] and OR: 1.058 [95% CI: 1.026 – 1.09], resp.). Only in underweight (< 18.5 kg/m ² ) and normal weight women the risk of LGA birth is strongly influenced by diabetes (OR 11.818 [95% CI: 1.156–120.782] and 1.564 [95% CI: 1.013–2.415]).

Conclusion Excessive weight gain is particularly important for non-obese women. These women are therefore a target cohort for intervention, as each prevented additional kilogram weight gain reduces the risk of LGA by more than 5%.

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.

Predicting childhood obesity using electronic health records and publicly available data

Background

Because of the strong link between childhood obesity and adulthood obesity comorbidities, and the difficulty in decreasing body mass index (BMI) later in life, effective strategies are needed to address this condition in early childhood. The ability to predict obesity before age five could be a useful tool, allowing prevention strategies to focus on high risk children. The few existing prediction models for obesity in childhood have primarily employed data from longitudinal cohort studies, relying on difficult to collect data that are not readily available to all practitioners. Instead, we utilized real-world unaugmented electronic health record (EHR) data from the first two years of life to predict obesity status at age five, an approach not yet taken in pediatric obesity research.

Methods and findings

We trained a variety of machine learning algorithms to perform both binary classification and regression. Following previous studies demonstrating different obesity determinants for boys and girls, we similarly developed separate models for both groups. In each of the separate models for boys and girls we found that weight for length z-score, BMI between 19 and 24 months, and the last BMI measure recorded before age two were the most important features for prediction. The best performing models were able to predict obesity with an Area Under the Receiver Operator Characteristic Curve (AUC) of 81.7% for girls and 76.1% for boys.

Conclusions

We were able to predict obesity at age five using EHR data with an AUC comparable to cohort-based studies, reducing the need for investment in additional data collection. Our results suggest that machine learning approaches for predicting future childhood obesity using EHR data could improve the ability of clinicians and researchers to drive future policy, intervention design, and the decision-making process in a clinical setting.

Diseases of Civilization - Cancer, Diabetes, Obesity and Acne - the Implication of Milk, IGF-1 and mTORC1

Nutrition and food are one of the most complex aspects of human lives, being influenced by biochemical, psychological, social and cultural factors. The Western diet is the prototype of modern dietary pattern and is mainly characterized by the intake of large amounts of red meat, dairy products, refined grains and sugar. Large amounts of scientific evidence positively correlate Western diet to acne, obesity, diabetes, heart disease and cancer, the so-called "diseases of civilization". The pathophysiological common ground of all these pathologies is the IGF-1 and mTORC pathways, which will be disscussed further in this paper.

Transferred maternal fatty acids stimulate fetal adipogenesis and lead to neonatal and adult obesity

The prevalence of adult and childhood obesity are increasing. Most of the human newborn's body fat accumulates in the last half of intrauterine life. Fat in the fetus was thought to be mostly synthesized from glucose, but now it is commonly accepted that the bulk of it is the product of placental transfer of maternal fatty acids. Transported fatty acids originate in maternal plasma "free" fatty acids, fatty acids hydrolyzed from maternal plasma triglycerides, and the poly-unsaturated fatty acid component of maternal phospholipids. Glucose remains an important precursor of alpha-glycerol phosphate, to which most transported fatty acids are eventually esterified. Maternal plasma lipids are elevated in late pregnancy and even more in obese and diabetic pregnant women. This accelerates the placental transport of fatty acids. The hypothesis presented in this paper rests on the observations that the exponential increase in fat tissue in the human embryo's body occurs in time to parallel the increase of lipids in the mother's blood and depends on the chemical affinity of the transcription factor PPAR gamma to fatty acids and on fatty acid stimulation of adipocyte generation from precursor cells. The hypothesis asserts that transported maternal fatty acids activate the transcription factors in the fetus and initiate conversion of the mesenchymal stem cells into adipocytes. In obese and diabetic mothers, the higher plasma lipids facilitate increased placental fatty acid transfer. This will increase adipocyte generation and, through this, the prevalence of babies with increased fat cell size and number. Babies born with increased adipose tissue cellularity will have greater probability of growing up to become obese adolescents and adults. These newborns, whose obesity is hyperplastic as well as hypertrophic, as adults will have difficulty losing weight through diet and exercise or will regain the lost weight more quickly than others without these characteristics. Accordingly, increased placental fatty acid transfer and accelerated adipocyte generation may explain not only neonatal obesity, but some aspects of the adult obesity epidemic also. It is therefore recommended that prevention of fetal fat cell hyperplasia, by lowering maternal plasma lipids in mid and late pregnancy, should be attempted in pregnancies at risk for macrosomia.

Continuous Glucose Monitoring, Glycemic Variability, and Excessive Fetal Growth in Pregnancies Complicated by Type 1 Diabetes

BACKGROUND

To examine trimester-specific associations among glycemic variability, fetal growth, and birthweight in pregnancies with type 1 diabetes mellitus (Type 1 DM).

METHODS

In this retrospective cohort study of 41 pregnant women with Type 1 DM, we used continuous glucose monitoring (CGM) data to calculate glycemic variability (coefficient of variation of glucose) over a 7-day interval in each trimester. Clinical data, including fetal biometry, birthweight, and perinatal complications, were extracted from medical records.

RESULTS

Women maintained good glycemic control during pregnancy, with mean HbA1c in the first, second, and third trimester 6.5%, 6.1%, and 6.4%, respectively. Sixty-three percent of infants were large for gestational age (LGA). Estimated fetal weight percentile (EFW%ile) and abdominal circumference percentile (AC%ile) increased during pregnancy, consistent with accelerated prenatal growth. Correlations between trimester-specific glycemic variability and EFW, AC, and birthweight were not statistically significant. After maternal age adjustment, glycemic variability was not associated with birthweight for any trimester (adj. β for first trimester: -38.46, 95% CI: -98.58 to 21.66; adj. β for second trimester: -12.20, 95% CI: -51.47 to 27.06; adj. β for third trimester: -26.26, 95% CI: -79.52 to 27.00).

CONCLUSIONS

The occurrence of LGA remains very high in contemporary U.S. women with Type 1 DM, despite the use of CGM and overall good glycemic control. Neither HbA1c nor glycemic variability predicted fetal overgrowth or birthweight. Since LGA is a key driver of maternal and newborn complications in pregnancies with Type 1 DM, our data emphasize the importance of investigating both glucose-dependent and glucose-independent underlying mechanisms.

Longitudinal Anthropometric Assessment of Rhesus Macaque (Macaca mulatta) Model of Huntington Disease

The neurodegeneration associated with Huntington disease (HD) leads to the onset of motor and cognitive impairment and their advancement with increased age in humans. In children at risk for HD, body measurement growth abnormalities include a reduction in BMI, weight, height, and head circumference. The transgenic HD NHP model was first reported in 2008, and progressive decline in cognitive behaviors and motor impairment have been reported. This study focuses on longitudinal body measurements in HD macaques from infancy through adulthood. The growth of HD macaques was assessed through head circumference, sagittal and transverse head, and crown-to-rump ('height') measurements and BMI. The animals were measured monthly from 0 to 72 mo of age and every 3 mo from 72 mo of age onward. A mixed-effect model was used to assess subject-specific effects in our nonlinear serial data. Compared with WT controls, HD macaques displayed different developmental trajectories characterized by increased BMI, head circumference, and sagittal head measurements beginning around 40 mo of age. The physiologic comparability between NHP and humans underscores the translational utility of our HD macaques to evaluate growth and developmental patterns associated with HD.

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.

Analysis of Factors Affecting the Body Mass Index in a National Sample of Iranian Children and Adolescents: Bootstrapping Regression

Background

This study aims to evaluate the effect of some factors, including birth weight, sex, age, waist circumference, family history of obesity, as well as some lifestyle factors as frequency of breakfast days and physical activity, on the body mass index among a nationally representative sample of Iranian children and adolescents by using bootstrapping regression.

Materials and Methods

This study was conducted as the third survey of a school-based surveillance system (CASPIAN-III study). Total participants were 5570 school students, aged 10-18 years, selected by multistage random cluster sampling from urban and rural areas of 27 provinces of Iran. Multiple linear regressions was used to evaluate the effect of various factors on obesity, but in our data the assumptions of this model violated, and possible solutions were not appropriate, therefore the bootstrapping regression based on the observations and errors resampling approaches was used as an alternative.

Results

The tests of significance showed that the effects of sex, age, waist circumference, family history obesity and frequency of breakfast days were clearly significant (P < 0.001). The effect of vigorous level of physical activity was significant in comparison to mild physical activity (P = 0.01). In comparison to low birth weight, medium and high birth weight had significant effect on obesity.

Conclusions

Bootstrap method is preferable in linear regression because of some theoretical properties like having any distributional assumptions on the residuals and hence allows for inference even if the errors do not follow normal distribution or constant error variance.

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.

Validity of Self-Reported Birth Weight: Results from a Norwegian Twin Sample

The association between birth weight and later life outcomes is of considerable interest in life-course epidemiology. Research often relies on self-reported measures of birth weight, and its validity is consequently of importance. We assessed agreement between self-reported birth weight and official birth records for Norwegian twins born 1967–1974. The intraclass correlation between self-reported birth weight and register-based birth weight was 0.91 in our final sample of 363 twins. It could be expected that 95% of self-reported birth-weight values will deviate from official records within a maximum of +446 grams and a minimum of −478 grams — around a mean deviation of 16 grams. Self-reported birth weight had a sensitivity of 0.78–0.89 and a positive predictive value of 0.59–0.85, and an overall weighted kappa of 0.71. We further assessed agreement by conducting two linear regression models where we respectively regressed self-reported birth weight and register-based birth weight on adult body mass index, a known association. The two models were not significantly different; however, there were different levels of significance in parameter estimates that warrant some caution in using self-reported birth weight. Reliability of self-reported birth weight was also assessed, based on self-reports in another sample of twins born 1935–1960 who had reported their birth weight in two questionnaires 34 years apart. The intraclass correlation was 0.86, which indicates a high degree of reliability. In conclusion, self-reported birth weight, depending on context and age when birth weight was reported, can be cautiously used.

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.

Low Birth Weight and Risk of Later-Life Physical Disability in Women

Background

There is strong evidence that low and high birth weight due to in-utero programming results in elevated risk for adult diseases, though less research has been performed examining the influence of birth weight and physical disability later in life.

Methods

Baseline data from 76,055 postmenopausal women in the Women's Health Initiative, a large multi-ethnic cohort, were used to examine the association between self-reported birth weight category (<6 lbs, 6-7 lbs 15 oz, 8-9 lbs 15 oz, and ≥10 lbs) and the self-reported physical functioning score on the RAND 36-item Health Survey. Linear regression models were adjusted for age, education, race/ethnicity, body mass index, and a comorbidity score.

Results

Unadjusted models indicate that women born in the lowest and highest birth weight categories have significantly lower physical functioning scores as compared to women born in the normal weight category (β = -2.22, p < .0001 and β = -3.56, p < .0001, respectively). After adjustments, the relationship between the lowest birth weight category and physical functioning score remained significant (β = -1.52, p < .0001); however, the association with the highest birth weight category dissipated.

Conclusions

Preconception and prenatal interventions aimed at reducing the incidence of low birth weight infants may subsequently reduce the burden of later-life physical disability.

Parametric modeling of quantile regression coefficient functions with censored and truncated data

Quantile regression coefficient functions describe how the coefficients of a quantile regression model depend on the order of the quantile. A method for parametric modeling of quantile regression coefficient functions was discussed in a recent article. The aim of the present work is to extend the existing framework to censored and truncated data. We propose an estimator and derive its asymptotic properties. We discuss goodness-of-fit measures, present simulation results, and analyze the data that motivated this article. The described estimator has been implemented in the R package qrcm.

Maternal BMI as a predictor of methylation of obesity-related genes in saliva samples from preschool-age Hispanic children at-risk for obesity

BACKGROUND

The study of epigenetic processes and mechanisms present a dynamic approach to assess complex individual variation in obesity susceptibility. However, few studies have examined epigenetic patterns in preschool-age children at-risk for obesity despite the relevance of this developmental stage to trajectories of weight gain. We hypothesized that salivary DNA methylation patterns of key obesogenic genes in Hispanic children would 1) correlate with maternal BMI and 2) allow for identification of pathways associated with children at-risk for obesity.

RESULTS

Genome-wide DNA methylation was conducted on 92 saliva samples collected from Hispanic preschool children using the Infinium Illumina HumanMethylation 450 K BeadChip (Illumina, San Diego, CA, USA), which interrogates >484,000 CpG sites associated with ~24,000 genes. The analysis was limited to 936 genes that have been associated with obesity in a prior GWAS Study. Child DNA methylation at 17 CpG sites was found to be significantly associated with maternal BMI, with increased methylation at 12 CpG sites and decreased methylation at 5 CpG sites. Pathway analysis revealed methylation at these sites related to homocysteine and methionine degradation as well as cysteine biosynthesis and circadian rhythm. Furthermore, eight of the 17 CpG sites reside in genes (FSTL1, SORCS2, NRF1, DLC1, PPARGC1B, CHN2, NXPH1) that have prior known associations with obesity, diabetes, and the insulin pathway.

CONCLUSIONS

Our study confirms that saliva is a practical human tissue to obtain in community settings and in pediatric populations. These salivary findings indicate potential epigenetic differences in Hispanic preschool children at risk for pediatric obesity. Identifying early biomarkers and understanding pathways that are epigenetically regulated during this critical stage of child development may present an opportunity for prevention or early intervention for addressing childhood obesity.

TRIAL REGISTRATION

The clinical trial protocol is available at ClinicalTrials.gov ( NCT01316653 ). Registered 3 March 2011.

Effect of Exclusive Breastfeeding Among Overweight and Obese Mothers on Infant Weight-for-Length Percentile at 1 Year

BACKGROUND

Breastfeeding is associated with decreased risk of childhood obesity. However, there is a strong correlation between maternal weight status and childhood obesity, and it is unclear whether or not breastfeeding among overweight mothers could mitigate this risk. Our goal was to examine whether or not exclusive breastfeeding (compared to formula feeding) among overweight and obese mothers is associated with lower weight-for-length (W/L) percentile at 1 year.

MATERIALS AND METHODS

Data from the Infant Feeding Practices II study were used. Infants who were preterm or underweight at 1 year, and mothers who were underweight before pregnancy, were excluded from analysis. There was a significant interaction between exclusive breastfeeding for 4 months and maternal prepregnancy weight status (normal weight, overweight, obese) on infant W/L percentile at 1 year. Stratified linear mixed-effects growth modeling controlling for covariates was created to test the relationship between exclusive breastfeeding and infant W/L percentile within each maternal weight category.

RESULTS

A total of 915 subjects met inclusion criteria. Normal weight and obese mothers who exclusively breastfed for 4 months had infants with a smaller rate of increase in W/L percentile during the first year compared with those who used formula. Infants of overweight and obese mothers who exclusively breastfed for 4 months had lower W/L percentile at 1 year than those who used formula.

CONCLUSIONS

Exclusive breastfeeding for 4 months among normal weight and obese mothers resulted in less increase in W/L percentiles in the first year. Obese mothers often have a difficult time initiating and maintaining breastfeeding. Concerted efforts are needed to support this population with breastfeeding.

Maternal obesity and prenatal programming

Obesity is a significant and increasing public health concern in the United States and worldwide. Clinical and epidemiological evidence clearly shows that genetic and environmental factors contribute to the increased susceptibility of humans to obesity and its associated comorbidities; the interplay of these factors is explained by the concept of epigenetics. The impact of maternal obesity goes beyond the newborn period; fetal programming during the critical window of pregnancy, can have long term detrimental effects on the offspring as well as future generations. Emerging evidence is uncovering a link between the clinical and molecular findings in the offspring with epigenetic changes in the setting of maternal obesity. Research targeted towards reducing the transgenerational propagation and developmental programming of obesity is vital in reducing the increasing rates of disease.

Milk: an epigenetic amplifier of FTO-mediated transcription? Implications for Western diseases

Single-nucleotide polymorphisms within intron 1 of the FTO (fat mass and obesity-associated) gene are associated with enhanced FTO expression, increased body weight, obesity and type 2 diabetes mellitus (T2DM). The N⁶-methyladenosine (m⁶A) demethylase FTO plays a pivotal regulatory role for postnatal growth and energy expenditure. The purpose of this review is to provide translational evidence that links milk signaling with FTO-activated transcription of the milk recipient. FTO-dependent demethylation of m⁶A regulates mRNA splicing required for adipogenesis, increases the stability of mRNAs, and affects microRNA (miRNA) expression and miRNA biosynthesis. FTO senses branched-chain amino acids (BCAAs) and activates the nutrient sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), which plays a key role in translation. Milk provides abundant BCAAs and glutamine, critical components increasing FTO expression. CpG hypomethylation in the first intron of FTO has recently been associated with T2DM. CpG methylation is generally associated with gene silencing. In contrast, CpG demethylation generally increases transcription. DNA de novo methylation of CpG sites is facilitated by DNA methyltransferases (DNMT) 3A and 3B, whereas DNA maintenance methylation is controlled by DNMT1. MiRNA-29s target all DNMTs and thus reduce DNA CpG methylation. Cow´s milk provides substantial amounts of exosomal miRNA-29s that reach the systemic circulation and target mRNAs of the milk recipient. Via DNMT suppression, milk exosomal miRNA-29s may reduce the magnitude of FTO methylation, thereby epigenetically increasing FTO expression in the milk consumer. High lactation performance with increased milk yield has recently been associated with excessive miRNA-29 expression of dairy cow mammary epithelial cells (DCMECs). Notably, the galactopoietic hormone prolactin upregulates the transcription factor STAT3, which induces miRNA-29 expression. In a retrovirus-like manner milk exosomes may transfer DCMEC-derived miRNA-29s and bovine FTO mRNA to the milk consumer amplifying FTO expression. There is compelling evidence that obesity, T2DM, prostate and breast cancer, and neurodegenerative diseases are all associated with increased FTO expression. Maximization of lactation performance by veterinary medicine with enhanced miRNA-29s and FTO expression associated with increased exosomal miRNA-29 and FTO mRNA transfer to the milk consumer may represent key epigenetic mechanisms promoting FTO/mTORC1-mediated diseases of civilization.

Convergence in insulin resistance between very severely obese and lean women at the end of pregnancy

AIMS

Disrupted intermediary metabolism may contribute to the adverse pregnancy outcomes in women with very severe obesity. Our aim was to study metabolism in such pregnancies.

METHODS

We recruited a longitudinal cohort of very severely obese (n = 190) and lean (n = 118) glucose-tolerant women for anthropometric and metabolic measurements at early, mid and late gestation and postpartum. In case-control studies of very severely obese and lean women we measured glucose and glycerol turnover during low- and high-dose hyperinsulinaemic-euglycaemic clamps (HEC) at early and late pregnancy and in non-pregnant women (each n = 6-9) and body fat distribution by MRI in late pregnancy (n = 10/group).

RESULTS

Although greater glucose, insulin, NEFA and insulin resistance (HOMA-IR), and greater weight and % fat mass (FM) was observed in very severely obese vs lean participants, the degree of worsening was attenuated in the very severely obese individuals with advancing gestation, with no difference in triacylglycerol (TG) concentrations between very severely obese and lean women at term. Enhanced glycerol production was observed in early pregnancy only in very severely obese individuals, with similar intrahepatic FM in very severely obese vs lean women by late gestation. Offspring from obese mothers were heavier (p = 0.04).

CONCLUSIONS/INTERPRETATION

Pregnancies complicated by obesity demonstrate attenuation in weight gain and insulin resistance compared with pregnancies in lean women. Increased glycerol production is confined to obese women in early pregnancy and obese and lean individuals have similar intrahepatic FM by term. When targeting maternal metabolism to treat adverse pregnancy outcomes, therapeutic intervention may be most effective applied early in pregnancy.

A rapid growth rate in early childhood is a risk factor for becoming overweight in late adolescence

AIM

We evaluated whether body mass index (BMI) and rapid growth in early life were associated with an increased risk of becoming overweight at 16 and 18 years of age.

METHODS

The study population comprised all children born in Sweden on the 15th of each month in 1981. Individuals born on the 5th, 10th and 20th of every month were added for counties with low population densities. Information on weight and height was collected from birth up to 18 years of age for 98.6% of the 3537 children identified.

RESULTS

Weight at 12 months of age was associated with being overweight at both 16 and 18 years of age. Rapid weight gain from birth to 12 months was associated with higher odds for being overweight later in life, and the weight gain between 18 months and four years of age was the strongest risk factor for being overweight in late adolescence in both sexes. There was no association between a birthweight of <2500 g or >4500 g and being overweight at 16 or 18 years of age.

CONCLUSION

Fast growth during early childhood was associated with an increased risk of being overweight later in life, emphasising the importance of early prevention.

Intergenerational transmission of macrosomia in women with gestational diabetes and normal glucose tolerance

OBJECTIVES

It has been suggested that neonatal macrosomia may contribute to increased risk of obesity and type 2 diabetes in later life. Much less is known about the association between maternal birth weight (MBW) and offspring birth weight (OBW). This retrospective study evaluated the prevalence of macrosomia in women with treated gestational diabetes mellitus (GDM) and normal glucose tolerance during pregnancy. The study also investigated associations between MBW and OBW.

STUDY DESIGN

Medical records of 519 pregnant women with treated GDM and 766 women with normal glucose tolerance, referred to the Gestational Diabetes Outpatient Clinic in Szczecin, Poland, were analyzed. The following data were assessed: maternal age, pregravid body weight, height, gestational weight gain, prior GDM, prior macrosomia, MBW and OBW. Birth weight was classified as small for gestational age (SGA), appropriate for gestational age (AGA), large for gestational age (LGA) and macrosomia (≥4000g). OBW was obtained from birth certificates, and MBW was obtained from birth certificates or self-report.

RESULTS

The overall prevalence of macrosomia was 8.1%, and was comparable in subgroups of women with and without GDM (7.7% and 8.4%, respectively; p=0.905). The frequencies of SGA, AGA and LGA did not differ between study groups. A positive correlation was found between MBW and OBW in women with treated GDM (r=0.211, p<0.001) and in women with normal glucose tolerance (r=0.220, p<0.001). Regardless of glucose tolerance status during pregnancy, the greatest proportion of macrosomic babies were born to mothers who were themselves born macrosomic (26.5% in mothers with GDM and 20.0% in mothers with normal glucose tolerance; p=0.631). On logistic regression, MBW was found to be a robust predictor of macrosomia in offspring [odds ratio (OR) 1.64, 95% confidence interval (CI) 1.15-2.36 in women with treated GDM; OR 1.35, 95% CI 1.07-1.76 in women with normal glucose tolerance). Other independent predictors of fetal macrosomia were gestational weight gain, prior macrosomia and pregravid body mass index (BMI).

CONCLUSIONS

MBW, prior macrosomia, pregravid BMI and gestational weight gain were predictors of macrosomia in offspring, but GDM was not. High MBW seems to contribute to intergenerational transmission of macrosomia.

Birth Weight and Social Trust in Adulthood: Evidence for Early Calibration of Social Cognition

Social trust forms the fundamental basis for social interaction within societies. Understanding the cognitive architecture of trust and the roots of individual differences in trust is of key importance. We predicted that one of the factors calibrating individual levels of trust is the intrauterine flow of nutrients from mother to child as indexed by birth weight. Birth weight forecasts both the future external environment and the internal condition of the individual in multiple ways relevant for social cognition. Specifically, we predicted that low birth weight is utilized as a forecast of a harsh environment, vulnerable condition, or both and, consequently, reduces social trust. The results of the study reported here are consistent with this prediction. Controlling for many confounds through sibling and panel designs, we found that lower birth weight reduced social trust in adulthood. Furthermore, we obtained tentative evidence that this effect is mitigated if adult environments do not induce stress.

Pre-gravid oral contraceptive use in relation to birth weight: a prospective cohort study

Few studies have evaluated the association between pregravid oral contraceptive (OC) use and birth weight, and findings have been conflicting. We conducted a prospective cohort study of 5921 pregnancy planners in Denmark to evaluate recency, duration, and type of OC used before conception in relation to infant birth weight. Participants completed online questionnaires and reported detailed information on contraceptive history and covariates at baseline. Participants completed bimonthly follow-up questionnaires to update their pregnancy status for up to 12 months or until conception occurred. Birth weight data were ascertained from the Danish Medical Birth Registry for 4046 live births delivered by study participants between 2008 and 2010. We used multivariable linear and log-binomial regression analyses to control for confounding. Mean birth weight was higher among women who had used OCs within 0-1 months (mean difference = 97 g, CI 26, 168) or 2-6 months (mean difference = 40 g, CI -5, 85) before conception, compared with more than 12 months before conception. Mean birth weight was lower among women who had used OCs for long durations (mean difference comparing ≥12 with <4 years of OC use = -85 g, CI -158, -11). Our findings indicate that pregravid OC use within 6 months of conception may be associated with a small increase in birth weight, but that long duration of use may have the opposite effect. Results were stronger among male infants, among 2nd and 4th generation OC users, and among users of OCs with a higher estrogen dose.

Maternal and neonatal outcomes for pregnancies before and after gastric bypass surgery

BACKGROUND

Interaction between maternal obesity, intrauterine environment and adverse clinical outcomes of newborns has been described.

METHODS

Using statewide birth certificate data, this retrospective, matched-control cohort study compared paired birth weights and complications of infants born to women before and after Roux-en-Y gastric bypass surgery (RYGB) and to matched obese non-operated women in several different groups. Women who had given birth to a child before and after RYGB (group 1; n=295 matches) and women with pregnancies after RYGB (group 2; n=764 matches) were matched to non-operated women based on age, body mass index (BMI) prior to both pregnancy and RYGB, mother's race, year of mother/s birth, date of infant births and birth order. In addition, birth weights of 13 143 live births before and/or after RYGB of their mothers (n=5819) were compared (group 3).

RESULTS

Odds ratios (ORs) for having a large-for-gestational-age (LGA) neonate were significantly less after RYGB than for non-surgical mothers: ORs for groups 1 and 2 were 0.19 (0.08-0.38) and 0.33 (0.21-0.51), respectively. In contrast, ORs in all three groups for risk of having a small for gestational age (SGA) neonate were greater for RYGB mothers compared to non-surgical mothers (ORs were 2.16 (1.00-5.04); 2.16 (1.43-3.32); and 2.25 (1.89-2.69), respectively). Neonatal complications were not different for group 1 RYGB and non-surgical women for the first pregnancy following RYGB. Pregnancy-induced hypertension and gestational diabetes were significantly lower for the first pregnancy of mothers following RYGB compared to matched pregnancies of non-surgical mothers.

CONCLUSION

Women who had undergone RYGB not only had lower risk for having an LGA neonate compared to BMI-matched mothers, but also had significantly higher risk for delivering an SGA neonate following RYGB. RYGB women were less likely than non-operated women to have pregnancy-related hypertension and diabetes.

Milk consumption during pregnancy increases birth weight, a risk factor for the development of diseases of civilization

Antenatal dietary lifestyle intervention and nutrition during pregnancy and early postnatal life are important for appropriate lifelong metabolic programming. Epidemiological evidence underlines the crucial role of increased birth weight as a risk factor for the development of chronic diseases of civilization such as obesity, diabetes and cancer. Obstetricians and general practitioners usually recommend milk consumption during pregnancy as a nutrient enriched in valuable proteins and calcium for bone growth. However, milk is not just a simple nutrient, but has been recognized to function as an endocrine signaling system promoting anabolism and postnatal growth by activating the nutrient-sensitive kinase mTORC1. Moreover, pasteurized cow’s milk transfers biologically active exosomal microRNAs into the systemic circulation of the milk consumer apparently affecting more than 11 000 human genes including the mTORC1-signaling pathway. This review provides literature evidence and evidence derived from translational research that milk consumption during pregnancy increases gestational, placental, fetal and birth weight. Increased birth weight is a risk factor for the development of diseases of civilization thus involving key disciplines of medicine. With regard to the presented evidence we suggest that dietary recommendations promoting milk consumption during pregnancy have to be re-evaluated.

Birth weight and subsequent risk of cancer

BACKGROUND

We aimed to determine the association between self-reported birth weight and incident cancer in the Women's Health Initiative Observational Study cohort, a large multiethnic cohort of postmenopausal women.

METHODS

65,850 women reported their birth weight by category (<6 lbs, 6-7 lbs 15 oz, 8-9 lbs 15 oz, and ≥10 lbs). All self-reported, incident cancers were adjudicated by study staff. We used Cox proportional hazards regression to estimate crude and adjusted hazard ratios (aHR) for associations between birth weight and: (1) all cancer sites combined, (2) gynecologic cancers, and (3) several site-specific cancer sites.

RESULTS

After adjustments, birth weight was positively associated with the risk of lung cancer (p=0.01), and colon cancer (p=0.04). An inverse trend was observed between birth weight and risk for leukemia (p=0.04). A significant trend was not observed with breast cancer risk (p=0.67); however, women born weighing ≥10 lbs were less likely to develop breast cancer compared to women born between 6 lbs-7 lbs 15 oz (aHR 0.77, 95% CI 0.63, 0.94).

CONCLUSION

Birth weight category appears to be significantly associated with the risk of any postmenopausal incident cancer, though the direction of the association varies by cancer type.

Impact of size at birth and prematurity on adult anthropometry in 4744 middle-aged Danes - The Inter99 study

Low birth weight is related to increased risk of developing cardiovascular disease and type 2 diabetes in adult life. Since obesity is closely associated with type 2 diabetes and cardiovascular disease, the relationship between size at birth and adult anthropometry is of interest as a mediator of the relationship between birth weight and metabolic diseases. The aim of this study was, therefore, to examine the effect of size at birth and prematurity on measures of adult anthropometry taking adult socio-economic status and lifestyle variables into account. Midwife records with information on mother's age and parity as well as weight, length and maturity at birth were traced in 4744 Danes born between 1939 and 1970. Measures of adult anthropometry (weight, height, body mass index (BMI), waist circumference, hip circumference and waist/hip ratio) had previously been recorded together with information on socio-economic factors, lifestyle and parental diabetes status. Mother's age, parity and diabetes status were associated with offspring birth weight. Size at birth was positively associated with adult height and weight, but only weakly associated with BMI and not associated with waist/hip ratio when adjusted for socio-economic and lifestyle factors. Infants born preterm were less growth restricted at birth and grew to be taller and heavier compared with term infants born small for gestational age. Altogether, this study does not find evidence that obesity or a central fat distribution is mediating the relationship between low birth weight and risk of cardiovascular disease or type 2 diabetes in later life.