The influence of birthweight and intrauterine environment on adiposity and fat distribution in later life

Environment-physiology, diet quality and energy balance: the influence of early life nutrition on future energy balance

Diseases caused by impaired regulation of energy balance, in particular obesity, represent a major global health burden. Although polymorphisms, lifestyle and dietary choices have been associated with differential risk of obesity and related conditions, a substantial proportion of the variation in disease risk remains unexplained. Evidence from epidemiological studies, natural experiments and from studies in animal models has shown that a poor intra-uterine environment is associated causally with increased risk of obesity and metabolic disease in adulthood. Induction of phenotypes that increase disease risk involves the fetus receiving cues from the mother about the environment which, via developmental plasticity, modify the phenotype of the offspring to match her environment. However, inaccurate information may induce an offspring phenotype that is mismatched to the future environment. Such mismatch has been suggested to underlie increased risk of metabolic disease associated with a poor early life environment. Recent studies have shown that induction of modified phenotypes in the offspring involves altered epigenetic regulation of specific genes. Identification of a central role of epigenetics in the aetiology of obesity and metabolic disease may facilitate the development of novel therapeutic interventions and of biomarkers of disease risk.

Maternal leptin predicts adiposity of the neonate

BACKGROUND

Increased adiposity at birth may identify infants at high risk of developing obesity. Maternal obesity and hyperglycemia in pregnancy are associated with increased neonatal adiposity; however, features of maternal obesity that contribute to increased neonatal adiposity need further study.

AIMS

To measure adiposity in neonates of obese and normal-weight women without gestational diabetes to test the hypothesis that obese women have neonates with increased adiposity compared to neonates of normal-weight women.

METHODS

Sixty-one pregnant women, with a normal or obese BMI, and their neonates participated in this cross-sectional study at an academic medical center. Neonatal adiposity, expressed as percent body fat (fat mass/body mass), was measured by air displacement plethysmography and cord blood was assayed for biomarkers.

RESULTS

Adiposity in neonates of obese and normal-weight mothers did not differ. Stratifying mothers by leptin level showed that neonates born to mothers with higher leptin had significantly higher adiposity (13.2 vs. 11.1%, p = 0.035). In the entire cohort, adiposity positively correlated with cord blood leptin (r = 0.48, p < 0.001) and adiponectin (r = 0.27, p = 0.04) levels.

CONCLUSION

Obesity in normoglycemic pregnant women was not associated with increased neonatal adiposity. High maternal leptin levels identified neonates with increased adiposity.

Visceral adipose tissue and leptin increase colonic epithelial tight junction permeability via a RhoA-ROCK-dependent pathway

Proinflammatory cytokines produced by immune cells play a central role in the increased intestinal epithelial permeability during inflammation. Expansion of visceral adipose tissue (VAT) is currently considered a consequence of intestinal inflammation. Whether VAT per se plays a role in early modifications of intestinal barrier remains unknown. The aim of this study was to demonstrate the direct role of adipocytes in regulating paracellular permeability of colonic epithelial cells (CECs). We show in adult rats born with intrauterine growth retardation, a model of VAT hypertrophy, and in rats with VAT graft on the colon, that colonic permeability was increased without any inflammation. This effect was associated with altered expression of tight junction (TJ) proteins occludin and ZO-1. In coculture experiments, adipocytes decreased transepithelial resistance (TER) of Caco-2 CECs and induced a disorganization of ZO-1 on TJs. Intraperitoneal administration of leptin to lean rats increased colonic epithelial permeability and altered ZO-1 expression and organization. Treatment of HT29-19A CECs with leptin, but not adiponectin, dose-dependently decreased TER and altered TJ and F-actin cytoskeleton organization through a RhoA-ROCK-dependent pathway. Our data show that adipocytes and leptin directly alter TJ function in CECs and suggest that VAT could impair colonic epithelial barrier.

Blood pressure and anthropometrics of 4-y-old children born after preimplantation genetic screening: follow-up of a unique, moderately sized, randomized controlled trial

BACKGROUND

Recent studies suggest that in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are associated with suboptimal cardiometabolic outcome in offspring. It is unknown whether preimplantation genetic screening (PGS), which involves embryo biopsy, affects blood pressure (BP), anthropometrics, and the frequency of received medical care.

METHODS

In this prospective multicenter follow-up study, we assessed BP, anthropometrics, and received medical care of 4-y-old children born to women who were randomly assigned to IVF/ICSI with PGS (n = 49) or without PGS (controls; n = 64). We applied linear and generalized linear mixed-effects models to investigate possible effects of PGS.

RESULTS

BP in the PGS and control groups was similar: 102/64 and 100/64 mm Hg, respectively. Main anthropometric outcomes in the PGS vs. control group were: BMI: 16.1 vs. 15.8; triceps skinfold: 108 vs. 98 mm; and subscapular skinfold: 54 vs. 53 mm (all P values > 0.05). More PGS children than controls had received paramedical care (speech, physical, or occupational therapy: 14 (29%) vs. 9 (14%); P = 0.03 in multivariable analysis). The frequency of medicial treatment was comparable.

CONCLUSION

PGS does not seem to affect BP or anthropometrics in 4-y-old children. The higher frequency of received paramedical care after PGS may suggest an effect of PGS on subtle developmental parameters.

Placental weight: relation to maternal weight and growth parameters of full-term babies at birth and during childhood

Human growth is a continuous process. Studies defining placental effect on prenatal and postnatal human growth are few. We studied the anthropometric data of hundred mothers who gave birth at term after an uncomplicated singleton pregnancy, and their infants in relation to their placental weight using linear regression analysis. Mother weight, placental weight, and infant length (BL), weight (BW), and head circumference (HC) were obtained at birth and during childhood period (4.5 ± 2 years) of age. At birth, placental weights were correlated significantly with maternal weights (r = 0.21, P = 0.031). Placental weights were significantly correlated with growth parameters of the child at birth and during childhood. Infant BW (r = 0.71, r < 0.001), body mass index SDS (BMI SDS) (r = 0.589, P < 0.001), length SDS (LSDS) (0.567, P < 0.001) and HC (r = 0.699, P < 0.001). During childhood, placental weights were correlated with BMI SDS (r = 0.296, P = 0.002) and HtSDS = (r = 0.254, P = 0.009). LSDS at birth was correlated significantly with HtSDS during childhood (r = 0.445, P < 0.001). Placental weight represents a good marker of fetal growth (at birth) and significantly correlates with early childhood growth in full-term infants.

Neonatal cord blood adiponectin and insulin levels in very low birth weight preterm and healthy full-term infants

BACKGROUND

There are few studies concerning adiponectin and insulin concentration in cord blood of very low birth weight (VLBW) preterm and full-term newborns, small and appropriate for gestational age (GA).

AIM

To compare adiponectin and insulin concentrations between preterm and full-term infants, and to determine their relation with birth weight (BW) and size for GA.

METHODS

A cross-sectional study of VLBW preterm newborns with GA < 32 weeks and BW < 1500 g, and full-term newborns with GA > 37 weeks born at our hospital between January 2010 and May 2011, was conducted.

EXCLUSION CRITERIA

major congenital malformation, inborn errors of metabolism, chromosomal anomalies. Adiponectin was determined by enzimoimunoassay with ELISA kits (R&D Systems, Minneapolis, MN) and insulin was assayed by chemiluminescence method.

RESULTS

A total of 127 newborns were studied, 55 VLBW preterm (28 SGA), and 72 full-term (7 SGA). Insulin cord blood concentrations in preterm and full-term newborns were similar. Adiponectin concentrations were significantly lower in preterm than in full-term infants: 1.57 ± 0.74 pg/ml versus 2.4 ± 0.22 pg/ml (p < 0.001), respectively. Regression analyses showed that, after controlling for several neonatal and maternal factors, preterm birth was the only significant predictor of adiponectin concentrations.

CONCLUSION

Being born prematurely is the main determinant factor for lower adiponectin concentration in umbilical cord blood of newborns.

Overweight in childhood, adolescence and adulthood and cardiovascular risk in later life: pooled analysis of three british birth cohorts

Background

Overweight and obesity in adulthood are established risk factors for adverse cardiovascular outcomes, but the contribution of overweight in childhood to later cardiovascular risk is less clear. Evidence for a direct effect of childhood overweight would highlight early life as an important target for cardiovascular disease prevention. The aim of this study was to assess whether overweight and obesity in childhood and adolescence contribute to excess cardiovascular risk in adults.

Methods and findings

Data from three British birth cohorts, born in 1946, 1958 and 1970, were pooled for analysis (n = 11,447). Individuals were categorised, based on body mass index (BMI), as being of normal weight or overweight/obese in childhood, adolescence and adulthood. Eight patterns of overweight were defined according to weight status at these three stages. Logistic regression models were fitted to assess the associations of patterns of overweight with self-reported type 2 diabetes, hypertension, and coronary heart disease (CHD) in adulthood (34–53 years). Compared to cohort members who were never overweight, those who were obese in adulthood had increased risk of all outcomes. For type 2 diabetes, the odds ratio was higher for obese adults who were also overweight or obese in childhood and adolescence (OR 12.6; 95% CI 6.6 to 24.0) than for those who were obese in adulthood only (OR 5.5; 95% CI 3.4 to 8.8). There was no such effect of child or adolescent overweight on hypertension. For CHD, there was weak evidence of increased risk among those with overweight in childhood. The main limitations of this study concern the use of self-reported outcomes and the generalisability of findings to contemporary child populations.

Conclusions

Type 2 diabetes and to a lesser extent CHD risk may be affected by overweight at all stages of life, while hypertension risk is associated more strongly with weight status in adulthood.

Neonatal anthropometrics and correlation to childhood obesity--data from the Danish Children's Obesity Clinic

Recent evidence has demonstrated the prenatal initiation of childhood obesity as epidemiological studies and animal studies have illustrated the effect of the intrauterine milieu for subsequent development of childhood obesity. This study investigates the relationship between severe childhood obesity and the preceding in utero conditions expressed by birth weight and birth length, birth-weight-for-gestational-age and neonatal ponderal index in a Danish cohort of 1,171 severely obese children (median age 11.48 years, range 3.13 to 17.98 years) with a mean body mass index-standard derivation score (BMI-SDS) of +2.96 (range +1.65 to +9.72) treated in our national referral centre. In a linear general regression model adjusted for socioeconomic status and breastfeeding duration, a significant linear correlation between BMI-SDS at time of enrolment and both birth weight (p, 3.8 × 10(-6)) and birth length (p, 6.1 × 10(-4)), birth-weight-for-gestational-age (p, 4.3 × 10(-7)) and the neonatal ponderal index (p, 0.02) was demonstrated. Duration of breastfeeding, however, was not found to be significant for either the BMI-SDS/BW or the BMI-SDS/BL correlation.

CONCLUSION

These results indicate that the prenatal period can be considered as a potential window of opportunity for prevention of childhood overweight and obesity and anthropological measurements may in theory be used to help identify neonates at high risk for developing childhood obesity.

Current thoughts on maternal nutrition and fetal programming of the metabolic syndrome

Chronic diseases such as type 2 diabetes and cardiovascular disease are the leading cause of death and disability worldwide. Although the metabolic syndrome has been defined in various ways, the ultimate importance of recognizing this combination of disorders is that it helps identify individuals at high risk for both type 2 diabetes and cardiovascular disease. Evidence from observational and experimental studies links adverse exposures in early life, particularly relating to nutrition, to chronic disease susceptibility in adulthood. Such studies provide the foundation and framework for the relatively new field of developmental origins of health and disease (DOHaD). Although great strides have been made in identifying the putative concepts and mechanisms relating specific exposures in early life to the risk of developing chronic diseases in adulthood, a complete picture remains obscure. To date, the main focus of the field has been on perinatal undernutrition and specific nutrient deficiencies; however, the current global health crisis of overweight and obesity demands that perinatal overnutrition and specific nutrient excesses be examined. This paper assembles current thoughts on the concepts and mechanisms behind the DOHaD as they relate to maternal nutrition, and highlights specific contributions made by macro- and micronutrients.

Epigenetic basis for fetal origins of age-related disease

The current concept of fetal origins of adult diseases describes in utero programming, or adaptation to a spectrum of adverse environmental conditions that ultimately leads to increased susceptibility to age-related diseases (e.g., type 2 diabetes and cardiovascular disease) later in life. Although the precise mechanism of this biological memory remains unclear, mounting evidence suggests an epigenetic basis. The increased susceptibility to chronic disease and involvement of multiple organ systems that is observed is analogous to the decline in resistance to disease that is typical of normal aging. Although the cumulative environment over the course of a lifetime can induce increasing epigenetic dysregulation, we propose that adverse events that occur during early development can induce significant additional dysregulation of the epigenome. Here, we describe the current evidence for fetal origins of adult disease and the associated role of epigenetic dysregulation. In addition, we present a new perspective on the induction of epigenetic alterations in utero, which subsequently lead to an aging phenotype marked by increased susceptibility to age-related diseases.

Testing a capacity-load model for hypertension: disentangling early and late growth effects on childhood blood pressure in a prospective birth cohort

BACKGROUND

In 2005, it was estimated that hypertension affected 26.4% of the adult population worldwide. By 2025, it is predicted that it will affect about 60% of adults, a total of 1.56 billion. Both pre- and postnatal growth patterns have been associated with later blood pressure (BP), but in contrasting directions. These inconsistent associations of growth during different developmental periods merit elucidation. We tested a theoretical model treating birth weight as a marker of homeostatic metabolic capacity, and childhood height, lean mass and fat mass as independent indices of metabolic load. We predicted that decreased capacity and increased load would be independently associated with increased BP.

METHODS AND FINDINGS

Data from the ALSPAC cohort on growth from birth to 7 years, and body composition by dual-energy X-ray absorptiometry and BP at 9 years, were analysed (n = 6579). Data were expressed as standard deviation scores (SDS) or standardised regression residuals (SRR). BP was independently and positively associated with each of height, lean mass and fat mass. In a joint model systolic BP was positively associated with conditional weight velocity [males 0.40 (95%CI: 0.37-0.44) & females 0.44 (95%CI: 0.40-0.47) SDS/SRR], but not birth weight [0.00 (95%CI: -0.03-0.04) & 0.03 (95%CI: -0.01-0.07) SDS/SDS]. Adjusting for height, lean mass and fat mass, the association of systolic BP and conditional weight velocity attenuated [0.00(95%CI: -0.09-0.08) & -0.06(95%CI: -0.14-0.03) SDS/SRR], whereas that with birth weight became negative [-0.10 (95%CI: -0.14-0.06) & -0.09 (95%CI: -0.13-0.05) SDS/SDS]. Similar results were obtained for diastolic BP and pulse pressure.

CONCLUSIONS

Consistent with our theoretical model, high metabolic load relative to metabolic capacity is associated with increased BP. Our data demonstrate the contribution of different growth and body composition components to BP variance, and clarify the developmental aetiology of hypertension.

The risk of maternal obesity to the long-term health of the offspring

The prevalence of maternal obesity has risen dramatically in recent years, with approximately one in five pregnant women in the UK now classed as obese (body mass index ≥ 30 kg/m(2) ) at antenatal booking. Obesity during pregnancy has been hypothesized to exert long-term health effects on the developing child through 'early life programming'. While this phenomenon has been well studied in a maternal undernutrition paradigm, the processes by which the programming effects of maternal obesity are mediated are less well understood. In humans, maternal obesity has been associated with a number of long-term adverse health outcomes in the offspring, including lifelong risk of obesity and metabolic dysregulation with increased insulin resistance, hypertension and dyslipidaemia, as well as behavioural problems and risk of asthma. The complex relationships between the maternal metabolic milieu and the developing foetus, as well as the potential influence of postnatal lifestyle and environment, have complicated efforts to study the programming effects of maternal overnutrition in humans. This review will examine the emerging evidence from human studies linking maternal obesity to adverse offspring outcomes.

The association of a nucleobindin 2 gene (NUCB2) variant with childhood adiposity

Nucleobindin 2 (NUCB2) is a precursor of nesfatin-1, a hypothalamic anorectic neuropeptide. The association between variants of the NUCB2 gene and adiposity was examined. 142 severely obese Chinese children in Singapore, and 384 normal weight Chinese children from a longitudinal cohort from Da Qing, China, were studied. NUCB2 was screened using PCR and direct sequencing in 29 severely obese children and 24 non-obese children, then screened for a variant c.1012C>G (Q338E, or rs757081) in the rest of the cohort using TaqMan probe. Five variants, including c.1012C>G (Q338E) were found. Genotyping for c.1012C>G found that the GG genotype was significantly less frequent in the obese group; odds ratio for obese subjects carrying the CC and CG genotypes was 2.29 (95% CI 1.17-4.49) in the dominant model, CC genotype 2.86 (95% CI 1.41-5.81) in the additive model, and C allele 1.57 (95% CI 1.17-2.1). The findings were replicated in an independent cohort of 372 obese and 390 normal weight Chinese children, where the odds ratio of obese subjects with CC and CG genotypes was 1.69 (95% CI 1.12-2.55). Within the Da Qing cohort, subjects with the GG genotype had significantly lower BMI and percentage ideal weight for height (WFH) at 5 and 8years of age. Subjects with lower birth weights also had more pronounced difference in WFH and BMI at 5 and 10years of age between GG subjects versus CC/CG subjects. We postulate that GG genotype is protective against excessive weight gain, and factors which predispose to excessive weight gain such as higher birth weights may ameliorate the effect.

Early invitation to food and/or multiple micronutrient supplementation in pregnancy does not affect body composition in offspring at 54 months: follow-up of the MINIMat randomised trial, Bangladesh

Growth patterns in early life are associated with later health. The effect of nutrition during in utero development on later body composition is unclear. We evaluated whether prenatal early invitation to food and/or multiple micronutrient supplementation (MMS) in pregnancy has an effect on offspring body composition at 54 months of age. In Maternal and Infant Nutrition Interventions in Matlab trial (ISRCTN16581394) in Bangladesh, 4436 pregnant women were randomised into six equally sized groups: double-masked supplementation with capsules of either 30 mg Fe and 400 μg folic acid, or 60 mg Fe and 400 μg folic acid, or MMS (15 micronutrients), was combined with a randomised early invitation (around 9 weeks) or a usual invitation (around 20 weeks) to start food supplementation (608 kcal 6 days per week). At 54 months, the body composition of the offspring was assessed by leg-to-leg bioelectrical impedance analysis. Of the 3267 live singletons with birth anthropometry, 2290 children were measured at 54 months, representing 70% of the live births. There was no interaction between the food and micronutrient supplementation on body composition outcomes. There were no significant differences in a range of anthropometric and body composition measurements, including weight, height, mid-upper arm circumference, head circumference, skinfold thickness, and fat mass and fat-free mass between the different prenatal food and micronutrient groups using an intention-to-treat analysis. This analysis shows that early invitation to food supplementation and MMS provided to rural Bangladeshi women during pregnancy did not affect offspring body composition at 54 months of age.

PVN pathways controlling energy homeostasis

Research into the control of energy balance has tended to focus on discrete brain regions, such as the brainstem, medulla, arcuate nucleus of the hypothalamus, and neocortex. Recently, a larger picture has begun to emerge in which the coordinated communication between these areas is proving to be critical to appropriate regulation of metabolism. By serving as a center for such communication, the paraventricular nucleus of the hypothalamus (PVH) is perhaps the most important brain nucleus regulating the physiological response to energetic challenges. Here we review recent advances in the understanding of the circuitry and function of the PVH.

Birth weight and overweight/obesity in adults: a meta-analysis

The objective of this study is to assess the association between birth weight and overweight/obesity in adults. The following MeSH terms were used: "birth weight," "obesity," "overweight." Fifteen studies involving a total of 211,457 persons were identified. Low birth weight (<2,500 g), as compared with normal birth weight (2,500-4,000 g), was not associated with increased risk of overweight/obesity (OR = 1.17, 95% CI 0.94, 1.46). High birth weight (≥ 4,000 g), as compared with normal birth weight, was associated with increased risk of overweight/obesity (OR = 1.46, 95% CI 1.27, 1.68). Low birth weight compared with normal birth weight, the total mean difference of BMI decreased 0.14 kg/m(2). High birth weight compared with normal birth weight, the total mean difference of BMI increased 0.76 kg/m(2). Low birth weight, as compared with a birth weight of ≥ 2,500 g, was not significantly associated with decreased risk of obesity (OR = 1.12, 95% CI 0.90-1.40). High birth weight, as compared with a birth weight of <4,000 g, was associated with increased risk of obesity (OR = 1.43, 95% CI 1.25-1.64). Low birth weight compared with birth weight ≥ 2,500 g, the total mean difference of BMI was decreased 0.42 kg/m(2); high birth weight compared with birth weight <4,000 g, the total mean difference of BMI was increased 0.79 kg/m(2).

CONCLUSION

Neither positively linear nor J- or U-shaped relations exist between birth weight and overweight/obesity in adults. It is high birth weight, not low birth weight, that is associated with increased risk of overweight/obesity in adults.

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

OBJECTIVE

To assess whether changes in the birth weight distribution or changes in the association of birth weight with the later risk of childhood overweight have contributed to the development of the obesity epidemic.

RESEARCH METHODS AND PROCEDURES

A Danish population-based cohort study of 124,615 girls and 128,346 boys (ages 6 to 13 years), born between 1936 and 1983, were studied. Birth weight and annual measurements of height and weight were obtained from school health records. Overweight was defined by BMI in relation to internationally accepted criteria. The relative risk of being overweight by birth weight was calculated separately for each age, sex, and time period.

RESULTS

The birth weight distribution remained relatively stable over time. Compared with children with a birth weight of 3.0 to 3.5 kg, the risk of overweight increased consistently with each increase in birth weight category among girls and boys and at all ages between 6 and 13 years. Furthermore, the association between birth weight and increased risk of overweight in childhood remained stable across a 48-year period.

DISCUSSION

The increase in the prevalence of overweight could not be explained by time trends in the distribution of birth weight or by changes in the association between birth weight and the later risk of overweight over time. This implies that, unless the prenatal environment influences the later risk of overweight without increasing birth weight, the environmental influences contributing to the obesity epidemic in children of school age operate in the early postnatal period.

The impact of childhood obesity on morbidity and mortality in adulthood: a systematic review

The objective of this study was to evaluate the evidence on whether childhood obesity is a risk factor for adult disease, independent of adult body mass index (BMI). Ovid MEDLINE (1948-May 2011), EMBASE (1980-2011 week 18) and the Cochrane Library (1990-2011) were searched for published studies of BMI from directly measured weight and height in childhood (2-19 years) and disease outcomes in adulthood. Data were synthesized in a narrative fashion. Thirty-nine studies (n 181-1.1 million) were included in the review. There was evidence for associations between childhood BMI and type 2 diabetes, hypertension and coronary heart disease. Few studies examined associations independent of adult BMI; these showed that effect sizes were attenuated after adjustment for adult BMI in standard regression analyses. Although there is a consistent body of evidence for associations between childhood BMI and cardiovascular outcomes, there is a lack of evidence for effects independent of adult BMI. Studies have attempted to examine independent effects using standard adjustment for adult BMI, which is subject to over-adjustment and problems with interpretation. Studies that use more robust designs and analytical techniques are needed to establish whether childhood obesity is an independent risk factor for adult disease.

Modernization and the onset of overweight and obesity in Bougainville and Solomon Islands children: cross-sectional and longitudinal comparisons between 1966 and 1986

This set of cross-sectional and longitudinal data from children and young adults in certain Bougainville and Solomon Islands populations undergoing rapid modernization during the period 1966-1986 reveals very different responses to essentially the same stimuli-the introduction and widespread availability of western dietary items and reductions in habitual activity. Our analyses of over 2,000 children and young adults first measured in 1966-1972, with follow-up surveys in 1968-1970 and 1985-1986, show changes in overweight/obesity in these communities have their onset around puberty, and are not related to differences in childhood growth stunting. The prevalence of overweight and obesity increased substantially during the period of this study among young adults, particularly women, and in groups with more Polynesian affinities, where the frequency of overweight (BMI ≥ 25) tripled over this 20-year interval. However, the BMI of the more Papuan groups on Bougainville remained remarkably stable, even though they were close to the epicenter of modernization during this period, the Bougainville Copper Mine.

Evidence for fetal programming of obesity with a focus on putative mechanisms

Obesity is associated with insulin resistance, the metabolic syndrome (a clustering of three or more of increased waist circumference, blood pressure, fasting glucose and fasting plasma triacylglycerol levels and reduced HDL levels), and a marked increase in the risk of type 2 diabetes and CHD. The impact of obesity differs between individuals, particularly between men and women and between ethnic groups. For example, in South Asians, although overall obesity is less prevalent, central obesity and the metabolic syndrome are more prevalent than in Europeans and this pattern is associated with the development of type 2 diabetes and CHD at an earlier age. It is important to examine individual risk factors contributing to obesity because they may have a different impact in population subgroups. Many factors contribute to the aetiology of obesity and there is increasing evidence to suggest that altered early development is one such factor and is associated with abnormal fat accumulation, the metabolic syndrome and type 2 diabetes in later life. The present review presents this evidence and discusses some of the mechanisms that may be involved in the pathogenesis of the programming of obesity.

Ability of the Actiwatch Accelerometer to Predict Free-Living Energy Expenditure in Young Children

OBJECTIVE

To determine whether activity counts obtained with the Actiwatch monitor are associated with total expenditure and body composition in young children.

RESEARCH METHODS AND PROCEDURES

Actiwatch activity monitors were tested in 29 children 4 to 6 years old under field conditions over eight days. Total energy expenditure (TEE) was assessed with the doubly labeled water (DLW) technique. Correlation analyses were used to identify variables related to energy expenditure and percentage body fat. Multiple linear regression analyses were used to examine the variance in TEE and percentage body fat explained by activity counts after adjusting for relevant covariates.

RESULTS

Both average total daily activity counts (658,816 +/- 201,657) and the pattern of activity were highly variable among subjects. TEE was significantly related to lean body mass (r = 0.45) and age (r = 0.48; p < 0.05 for both). Activity counts alone were not associated with TEE. In multiple linear regression analyses, TEE was independently associated with only lean body mass. Percentage fat mass was independently associated with body weight, being a girl, and being white, but not with average total activity counts.

DISCUSSION

Activity counts obtained with the Actiwatch under free-living conditions do not reflect TEE in 4- to 6-year-old children and are not correlated with percentage fat mass. Therefore, average total activity counts obtained with the Actiwatch may be of limited value in identifying children at risk for becoming obese.

Bases biológicas e evidências epidemiológicas da contribuição do crescimento fetal e pós-natal na composição corporal: uma revisão

OBJETIVOS: apresentar as bases biológicas e evidências epidemiológicas do crescimento fetal e pós-natal relacionadas ao tamanho e composição corporal. MÉTODOS: a busca de artigos publicados nos últimos 15 anos foi realizada nas bases de dados Lilacs, SciELO, Medline através dos descritores: crescimento, restrição do crescimento fetal, baixo peso ao nascer, aceleração compensatória do crescimento, composição corporal, índice de massa corporal e hormônios. Os estudos foram selecionados de acordo com a pertinência às evidências a serem analisadas. RESULTADOS: os artigos apontam para a influência da restrição do crescimento intraútero na supressão da termogênese e regulação hormonal, que por sua vez interferem no ganho de peso após o nascimento, e explicam como ambos os processos, restrição do crescimento fetal e rápido ganho de peso pós-natal, influenciam as medidas corporais em fases posteriores da vida, com consequências que poderão afetar gerações. CONCLUSÕES: o crescimento fetal influencia o padrão de crescimento pós-natal devido a diversos fatores relacionados à regulação hormonal, porém existe ainda uma lacuna sobre a contribuição da somação entre crescimento fetal e pós-natal no tamanho e composição corporal em fases posteriores da vida.

Obesity and pulmonary disease: unanswered questions

Obesity is associated with risk of pulmonary disease, and adversely affects lung function. The parallel increase in obesity and asthma suggests the two conditions are linked; indeed, they can worsen each other. Obesity and inadequate asthma control are associated with poor quality of life, and place a high economic burden on public health. Although the obesity-lung interaction is a major issue for basic research and clinical studies, various questions remain unanswered. Do intrauterine and early life factors impact on the development of obesity and lung disease? If so, can this be prevented? Asthma is generally more severe in obese subjects, but is adiposity a driver of a new asthma phenotype that features greater morbidity and mortality, worse control and decreased response to medications? Obese individuals have small lung volumes, hence their airway calibre is reduced and airway resistance is increased. What puzzles physicians is whether peripheral airways undergo remodelling, which would increase bronchoconstriction. Obese asthmatics respond suboptimally to anti-inflammatory treatment, which raises the question: 'what drug for what patient?' Life expectancy is decreased in obesity and in chronic pulmonary disorders, but does obesity protect against or trigger chronic obstructive pulmonary disease? The time has come to find answers to these questions.

Birth weight and obesity risk at first grade of high school in a non-concurrent cohort of Chilean children

Objective

To determine the association of birth weight with obesity risk at first grade of high school in Chilean children after accounting for potential confounding factors.

Design

National non-concurrent cohort of newborns. Sociodemographic information, height, weight and anthropometric measurements at first grade of high school were analysed. Birth weight was classified as macrosomia (≥4000 g), by gestational age and by ponderal index. The relationship between birth weight and obesity at first grade of high school (BMI ≥ 95th percentile of the US Centers for Disease Control and Prevention's reference) was assessed using logistic regression models adjusted for sociodemographic information at delivery.

Setting

First grade of public high school of low and middle socio-economic status in the whole country (about 77 % of Chilean children in this age group).

Subjects

Newborns (n 119 070) and the same number of high-school students.

Results

A positive relationship of high ponderal index (OR = 1·86, 95 % CI 1·69, 2·03), birth weight ≥4000 g (OR = 1·66, 95 % CI 1·54, 1·78) and large for gestational age (OR = 1·69, 95 % CI 1·58, 1·81) with obesity at adolescence (P < 0·001) was found. Macrosomic children had a higher risk of being obese at first grade of high school after controlling for prenatal confounding variables (OR = 1·63, 95 % CI 1·52, 1·76; P < 0·001).

Conclusions

A direct relationship between high birth weight and obesity at first grade of high school was observed in this group of Chilean children. The results highlight the significance of birth weight as a simple tool to be used as an indicator of obesity risk for children by health-care providers.

Family income trajectory during childhood is associated with adiposity in adolescence: a latent class growth analysis

BACKGROUND

Childhood socioeconomic disadvantage has been linked with obesity in cross-sectional research, although less is known about how changes in socioeconomic status influence the development of obesity. Researchers have hypothesized that upward socioeconomic mobility may attenuate the health effects of earlier socioeconomic disadvantage; while downward socioeconomic mobility might have a negative influence on health despite relative socioeconomic advantages at earlier stages. The purpose of the current study was to characterize trajectories of family income during childhood, and to evaluate the influence of these trajectories on adiposity at age 15.

METHODS

Data were collected as part of the Study of Early Child Care and Youth Development (SECCYD) between 1991 and 2007 at 10 sites across the United States. A latent class growth analysis (LCGA) was conducted to identify trajectories of family income from birth to 15 years of age. Analyses of covariance (ANCOVAs) were conducted to determine whether measures of adiposity differed by trajectory, while controlling for relevant covariates.

RESULTS

The LCGA supported a 5-class trajectory model, which included two stable, one downward, and two upward trajectories. ANCOVAs indicated that BMI percentile, waist circumference, and skinfold thicknesses at age 15 differed significantly by trajectory, such that those who experienced downward mobility or stable low income had greater adiposity relative to the more advantaged trajectories. Conversely, upwardly mobile children and those with consistently adequate incomes had similar and more positive outcomes relative to the most disadvantaged trajectories.

CONCLUSIONS

Findings suggest that promoting upward socioeconomic mobility among disadvantaged families may have a positive impact on obesity-related outcomes in adolescence.

Investigation into longitudinal dietary behaviours and household socio-economic indicators and their association with BMI Z-score and fat mass in South African adolescents: the Birth to Twenty (Bt20) cohort

Objective

The present study aimed to assess the relationship between dietary habits, change in socio-economic status and BMI Z-score and fat mass in a cohort of South African adolescents.

Design

In the longitudinal study, data were collected at ages 13, 15 and 17 years on a birth cohort who have been followed since 1990. Black participants with complete dietary habits data (breakfast consumption during the week and at weekends, snacking while watching television, eating main meal with family, lunchbox use, number of tuck shop purchases, fast-food consumption, confectionery consumption and sweetened beverage consumption) at all three ages and body composition data at age 17 years were included in the analyses. Generalized estimating equations were used to test the associations between individual longitudinal dietary habits and obesity (denoted by BMI Z-score and fat mass) with adjustments for change in socio-economic status between birth and age 12 years.

Setting

Birth to Twenty (Bt20) study, Soweto-Johannesburg, South Africa.

Subjects

Adolescents (n 1298; 49·7 % male).

Results

In males, the multivariable analyses showed that soft drink consumption was positively associated with both BMI Z-score and fat mass (P < 0·05). Furthermore, these relationships remained the same after adjustment for socio-economic indicators (P < 0·05). No associations were found in females.

Conclusions

Longitudinal soft drink consumption was associated with increased BMI Z-score and fat mass in males only. Fridge ownership at birth (a proxy for greater household disposable income in this cohort) was shown to be associated with both BMI Z-score and fat mass.

Peripheral adiposity in relation to offspring birth size in women with and without gestational diabetes: preliminary data

OBJECTIVE

To document the relationship between maternal body composition parameters and offspring anthropometric measurements.

METHODS

A prospective sample of 48 pregnant women with either gestational diabetes (GDM, n=21) or normal glucose tolerance (NGT, n=27) was studied. Maternal weight, hip circumference and skinfold thicknesses were obtained at 32 weeks of gestation. Offspring length and weight, as well as cranial and thoracic perimeters were obtained at birth.

RESULTS

Reported maternal pregravid BMI correlated with offspring thoracic perimeter (ρ=0.52, P<0.05) and tended to correlate with birth weight (ρ=0.41, P=0.07). There were significant correlations between hip circumference and pregravid BMI, and with biceps, triceps, subscapular, thigh and total sum of skinfold thicknesses (ρ=0.53-0.75, all P<0.01). Hip circumference also correlated with offspring length (ρ=0.61), weight (ρ=0.75) and thoracic perimeter (ρ=0.60, all P<0.05). Maternal hip circumference was an independent and significant predictor of offspring weight, explaining 14.1% of the observed variance (P<0.05).

CONCLUSION

In a sample of women with and without GDM, maternal hip circumference was strongly related to other body composition estimates and was also predictive of offspring size measurements at birth.

Measures of birth size in relation to risk of prostate cancer: the Malmö Diet and Cancer Study, Sweden

There is some evidence that perinatal factors, specifically birth weight (BW), may be related to the onset of prostate cancer (PRCA). This case–control study, nested within the Malmö Diet and Cancer Cohort Study, used archived birth record data from 308 incident PRCA cases diagnosed between 1991 and 2005, and 637 age-matched controls among 4781 men born (1923–1945) in Malmö and Lund, Sweden. We applied conditional logistic regression to examine the birth size–PRCA association, including tumour subtypes, adjusting for perinatal and adult factors. Compared with controls, cases had a non-significantly higher mean BW and were more likely to have high (>4000 g) BW (21% v. 18%), but did not differ in other birth size measures, nor in mean adult body mass index . We observed a non-linear association between BW and PRCA risk. Compared with BWs between 3000 and 3500 g (reference), the fully adjusted odds ratios (OR, 95% CI) were 0.55 (0.33–0.91) for <3000 g, 0.86 (0.61–1.22) for 3500–4000 g and 0.98 (0.64–1.50) for >4000 g. Among men with aggressive tumours, the reduction in risk for those with BWs <3000 g (OR 0.26, 95% CI 0.09–0.72) was stronger than the rate of risk for PRCA overall. Crude risk estimates were minimally attenuated when adjusted for gestational age, maternal age, birth order and adult factors. Birth length, head circumference and placental weight were not associated with prostate cancer. Our results indicate a protective effect of lower BW on risk of total and aggressive prostate cancer, rather than any direct effect of larger birth size.

Next steps in obesity prevention: altering early life systems to support healthy parents, infants, and toddlers

There is an urgent need for effective, sustainable child obesity prevention strategies. Progress toward this goal requires strengthening current approaches to add a component that addresses pregnancy onward. Altering early-life systems that promote intergenerational transmission of obesity holds promise for interrupting the continuing cycle of the obesity epidemic. A 2011 Institute of Medicine (IOM) report emphasizes the need for interventions early in life to prevent obesity. A 2010 IOM report called for addressing gaps in existing obesity research evidence by using a systems perspective, simultaneously addressing interacting obesity promoting factors in multiple sectors and at multiple societal levels. A review of evidence from basic science, prevention, and systems research supports an approach that (1) begins at the earliest stages of development, and (2) uses a systems framework to simultaneously implement health behavior and environmental changes in communities.

Gestational diabetes and subsequent growth patterns of offspring: the National Collaborative Perinatal Project

Our objective was to test the hypothesis that intrauterine exposure to gestational diabetes [GDM] predicts childhood growth independent of the effect on infant birthweight. We conducted a prospective analysis of 28,358 mother-infant pairs who enrolled in the National Collaborative Perinatal Project between 1959 and 1965. The offspring were followed until age 7. Four hundred and eighty-four mothers (1.7%) had GDM. The mean birthweight was 3.2 kg (range 1.1-5.6 kg). Maternal characteristics (age, education, race, family income, pre-pregnancy body mass index and pregnancy weight gain) and measures of childhood growth (birthweight, weight at ages 4, and 7) differed significantly by GDM status (all P < 0.05). As expected, compared to their non-diabetic counterparts, mothers with GDM gave birth to offspring that had higher weights at birth. The offspring of mothers with GDM were larger at age 7 as indicated by greater weight, BMI and BMI z-score compared to the offspring of mothers without GDM at that age (all P < 0.05). These differences at age 7 persisted even after adjustment for infant birthweight. Furthermore, the offspring of mothers with GDM had a 61% higher odds of being overweight at age 7 compared to the offspring of mothers without GDM after adjustment for maternal BMI, pregnancy weight gain, family income, race and birthweight [OR = 1.61 (95%CI:1.07, 1.28)]. Our results indicate that maternal GDM status is associated with offspring overweight status during childhood. This relationship is only partially mediated by effects on birthweight.

Placental restriction reduces insulin sensitivity and expression of insulin signaling and glucose transporter genes in skeletal muscle, but not liver, in young sheep

Poor growth before birth is associated with impaired insulin sensitivity later in life, increasing the risk of type 2 diabetes. The tissue sites at which insulin resistance first develops after intrauterine growth restriction (IUGR), and its molecular basis, are unclear. We have therefore characterized the effects of placental restriction (PR), a major cause of IUGR, on whole-body insulin sensitivity and expression of molecular determinants of insulin signaling and glucose uptake in skeletal muscle and liver of young lambs. Whole-body insulin sensitivity was measured at 30 d by hyperinsulinaemic euglycaemic clamp and expression of insulin signaling genes (receptors, pathways, and targets) at 43 d in muscle and liver of control (n = 15) and PR (n = 13) lambs. PR reduced size at birth and increased postnatal growth, fasting plasma glucose (+15%, P = 0.004), and insulin (+115%, P = 0.009). PR reduced whole-body insulin sensitivity (-43%, P < 0.001) and skeletal muscle expression of INSR (-36%), IRS1 (-28%), AKT2 (-44%), GLUT4 (-88%), GSK3α (-35%), and GYS1 (-31%) overall (each P < 0.05) and decreased AMPKγ3 expression in females (P = 0.030). PR did not alter hepatic expression of insulin signaling and related genes but increased GLUT2 expression (P = 0.047) in males. Whole-body insulin sensitivity correlated positively with skeletal muscle expression of IRS1, AKT2, HK, AMPKγ2, and AMPKγ3 in PR lambs only (each P < 0.05) but not with hepatic gene expression in control or PR lambs. Onset of insulin resistance after PR and IUGR is accompanied by, and can be accounted for by, reduced expression of insulin signaling and metabolic genes in skeletal muscle but not liver.

Born with low birth weight in rural Southern India: what are the metabolic consequences 20 years later?

OBJECTIVE

Low birth weight (LBW) is common in the Indian population and may represent an important predisposing factor for type 2 diabetes (T2D) and the metabolic syndrome. Intensive metabolic examinations in ethnic LBW Asian Indians have been almost exclusively performed in immigrants living outside India. Therefore, we aimed to study the metabolic impact of being born with LBW in a rural non-migrant Indian population.

SUBJECTS AND METHODS

One hundred and seventeen non-migrant, young healthy men were recruited from a birth cohort in a rural part of south India. The subjects comprised 61 LBW and 56 normal birth weight (NBW) men, with NBW men acting as controls. Subjects underwent a hyperinsulinaemic euglycaemic clamp, i.v. and oral glucose tolerance tests and a dual-energy X-ray absorptiometry scan. The parents' anthropometric status and metabolic parameters were assessed.

RESULTS

Men with LBW were shorter (167±6.4 vs 172±6.0 cm, P<0.0001), lighter (51.9±9 vs 55.4±7 kg, P=0.02) and had a reduced lean body mass (42.1±5.4 vs 45.0±4.5 kg, P=0.002) compared with NBW controls. After adjustment for height and weight, the LBW subjects had increased diastolic blood pressure (77±6 vs 75±6 mmHg, P=0.01). Five LBW subjects had impaired glucose tolerance. In vivo insulin secretion and peripheral insulin action were similar in both the groups. Mothers of the LBW subjects were 3 cm shorter than the control mothers.

CONCLUSION

Only subtle features of the metabolic syndrome and changes in body composition among LBW rural Indians were found. Whether other factors such as urbanisation and ageing may unmask more severe metabolic abnormalities may require a long-term follow-up.

Influence of pre- and peri-natal nutrition on skeletal acquisition and maintenance

Early life nutrition has substantial influences on postnatal health, with both under- and overnutrition linked with permanent metabolic changes that alter reproductive and immune function and significantly increase metabolic disease risk in offspring. Since perinatal nutrition depends in part on maternal metabolic condition, maternal diet during gestation and lactation is a risk factor for adult metabolic disease. Such developmental responses may be adaptive, but might also result from constraints on, or pathological changes to, normal physiology. The rising prevalence of both obesity and osteoporosis, and the identification of links among bone, fat, brain, and gut, suggest that obesity and osteoporosis may be related, and moreover that their roots may lie in early life. Here we focus on evidence for how maternal diet during gestation and lactation affects metabolism and skeletal acquisition in humans and in animal models. We consider the effects of overall caloric restriction, and macronutrient imbalances including high fat, high sucrose, and low protein, compared to normal diet. We then discuss potential mechanisms underlying the skeletal responses, including perinatal developmental programming via disruption of the perinatal leptin surge and/or epigenetic changes, to highlight unanswered questions and identify the most critical areas for future research.

Influence of parental overweight on the association of birth weight and fat distribution later in childhood

OBJECTIVE

To examine whether the association between birth weight and fat distribution in childhood is modified by parental overweight.

METHODS

Cross-sectional study of 728 Danish children aged 8-10 and 14-16 years. The main outcomes were waist circumference, waist-to-height ratio, subscapular skinfold, and subscapular-to-triceps skinfold ratio. Analyses were stratified by parental overweight status (none vs. ≥1 overweight parent) for each dependent variable, expressed as z-scores.

RESULTS

Birth weight z-score was negatively associated with waist circumference (β -0.08 SD; 95% CI -0.15, -0.02), waist-to-height ratio (β -0.15 SD; 95% CI -0.22, -0.07), and subscapular-to-triceps ratio (β -0.28 SD; 95% CI -0.44, -0.12) after adjustment for sex, age, puberty, preterm birth, BMI, height, socio-economic status, mother's age at delivery, parity, breastfeeding, energy intake, and aerobic fitness in the group with ≥1 overweight parent. Birth weight was negatively associated with subscapular skinfold in groups with (β -0.16 SD; 95% CI -0.24, -0.06) and without overweight parents (β -0.09 SD; 95% CI -0.16, -0.02), but the magnitude of the association was greater in the former group.

CONCLUSION

The association between birth weight and fat distribution seems to be influenced by parental overweight. Lower birth weights are associated with central adiposity among offspring of overweight parents.

Birth size and childhood growth as determinants of physical functioning in older age: the Helsinki Birth Cohort Study

The study reports on the associations of infant and childhood anthropometric measurements, early growth, and the combined effect of birth weight and childhood body mass index with older age physical functioning among 1,999 individuals born in 1934-1944 and belonging to the Helsinki Birth Cohort Study. Physical functioning was assessed by the Short Form 36 scale. Anthropometric data from infancy and childhood were retrieved from medical records. The risk of lower Short Form 36 physical functioning at the mean age of 61.6 years was increased for those with birth weight less than 2.5 kg compared with those weighing 3.0-3.5 kg at birth (odds ratio (OR) = 2.73, 95% confidence interval (CI): 1.57, 4.72). The gain in weight from birth to age 2 years was associated with decreased risk of lower physical functioning for a 1-standard deviation increase (OR = 0.84, 95% CI: 0.75, 0.94). The risk of lower physical functioning was highest for individuals with birth weight in the lowest third and body mass index at 11 years of age in the highest third compared with those whose birth weight was in the middle third and body mass index at age 11 years was in the highest third (OR = 3.08, 95% CI: 1.83, 5.19). The increasing prevalence of obesity at all ages and the aging of populations warrant closer investigation of the role of weight trajectories in old age functional decline.

Developmental programming of adult obesity and cardiovascular disease in rodents by maternal nutrition imbalance

Studies on fetal undernutrition have generated the hypothesis that fetal programming corresponds to an attempt of the fetus to adapt to adverse conditions encountered in utero. These adaptations would be beneficial if these conditions prevail later in life, but they become detrimental in the case of normal or plentiful nutrition and favor the appearance of the metabolic syndrome. In this article, the discussion is limited to the developmental programming of obesity and cardiovascular disorders caused by an early mismatched nutrition, particularly intrauterine growth retardation followed by postnatal catch-up growth. Selected data in humans are reviewed before evoking some mechanisms revealed or suggested by experiments in rodents. A variety of physiologic mechanisms are implicated in obesity programming, 2 of which are detailed. In some, but not all observations, hyperphagia resulting namely from perturbed development of the hypothalamic circuitry devoted to appetite regulation may contribute to obesity. Another contribution may be the developmental changes in the population of fat cell precursors in adipose tissue. Even if the link between obesity and cardiovascular disease is well established, alteration of blood pressure regulation may appear independently of obesity. A loss of diurnal variation in heart rate and blood pressure in adulthood has resulted from maternal undernutrition followed by postnatal overnutrition. Further research should clarify the effect of mismatched early nutrition on the development of brain centers regulating energy intake, energy expenditure, and circadian rhythms.

Effects of maternal smoking during pregnancy on body composition in offspring

BACKGROUND

The aim of the present cross-sectional study was to use objective methods to assess the association between maternal smoking and body composition in offspring.

METHODS

A total of 2508 grade 4 school children were enrolled; all underwent lifestyle disease and passive smoking screening. Children were classified into four groups according to their urinary cotinine level and maternal smoking status during or before pregnancy. Items measured on lifestyle disease screening were compared among the four groups.

RESULTS

Only degree of obesity (DO) and body mass index (BMI) were significantly associated with maternal smoking during pregnancy. The prevalence of both DO >20% and DO >30%, and BMI >22% and BMI >25% was highest in children of mothers who smoked during pregnancy. These children had a tendency toward shorter height and increased weight although it was not statistically significant. There were no significant differences between maternal smoking status and lipid profile among groups. Confounders such as food, exercise and sleep were able to be eliminated.

CONCLUSION

Maternal smoking during pregnancy may be an independent risk factor of changing body composition in offspring, that is, shorter height and increased weight.

Fetoplacental vascular endothelial dysfunction as an early phenomenon in the programming of human adult diseases in subjects born from gestational diabetes mellitus or obesity in pregnancy

Gestational diabetes mellitus (GDM) and obesity in pregnancy (OP) are pathological conditions associated with placenta vascular dysfunction coursing with metabolic changes at the fetoplacental microvascular and macrovascular endothelium. These alterations are seen as abnormal expression and activity of the cationic amino acid transporters and endothelial nitric oxide synthase isoform, that is, the "endothelial L-arginine/nitric oxide signalling pathway." Several studies suggest that the endogenous nucleoside adenosine along with insulin, and potentially arginases, are factors involved in GDM-, but much less information regards their role in OP-associated placental vascular alterations. There is convincing evidence that GDM and OP prone placental endothelium to an "altered metabolic state" leading to fetal programming evidenced at birth, a phenomenon associated with future development of chronic diseases. In this paper it is suggested that this pathological state could be considered as a metabolic marker that could predict occurrence of diseases in adulthood, such as cardiovascular disease, obesity, diabetes mellitus (including gestational diabetes), and metabolic syndrome.

Prepregnancy body mass index and gestational weight gain in relation to child body mass index among siblings

There is increasing evidence that in utero effects of excessive gestational weight gain may result in increased weight in children; however, studies have not controlled for shared genetic or environmental factors between mothers and children. Using 2,758 family groups from the Collaborative Perinatal Project, the authors examined the association of maternal prepregnancy body mass index (BMI) and gestational weight gain on child BMI at age 4 years using both conventional generalized estimating equations and fixed-effects models that account for shared familial factors. With generalized estimating equations, prepregnancy BMI and gestational weight gain had similar associations with the child BMI z score (β = 0.09 units, 95% confidence interval (CI): 0.08, 0.11; and β = 0.07 units, 95% CI: 0.04, 0.11, respectively. However, fixed effects resulted in null associations for both prepregnancy BMI (β = 0.03 units, 95% CI: -0.01, 0.07) and gestational weight gain (β = 0.03 units, 95% CI: -0.02, 0.08) with child BMI z score at age 4 years. The positive association between gestational weight gain and child BMI at age 4 years may be explained by shared family characteristics (e.g., genetic, behavioral, and environmental factors) rather than in utero programming. Future studies should continue to evaluate the relative roles of important familial and environmental factors that may influence BMI and obesity in children.

Are ICSI adolescents at risk for increased adiposity?

BACKGROUND

Puberty is a critical period for the development of cardio-metabolic disturbances, including a more central body fat distribution. It is still unclear if IVF and more specifically ICSI, can permanently and detrimentally affect body fat accumulation in the human offspring. Therefore, adiposity and body fat distribution in 14-year-old adolescents born after ICSI were investigated.

METHODS

Body composition data, including anthropometry (weight, height and BMI), skinfold thicknesses (peripheral: triceps and biceps skinfolds; central: supra-iliacal and subscapular skinfolds; total: sum of the four skinfolds) and circumferences (waist, mid-upper arm) were compared between 217 ICSI singletons (116 boys, 101 girls) and 223 singletons (115 boys, 108 girls) born after spontaneous conception (SC). ICSI teenagers were part of a previously published ICSI cohort followed since birth; SC controls were recruited from schools in the surroundings.

RESULTS

Among all boys, no differences in body composition measurements were found between the ICSI and SC group, taking into account confounding variables. In boys with more advanced pubertal stages, a significantly higher sum of peripheral skinfolds was found in the ICSI group compared with the SC group (difference 3.5 mm, 95% confidence interval 0.3-6.6). In girls, peripheral adiposity assessed by skinfolds and mid-upper arm circumference, and central adiposity assessed by skinfolds and waist circumference as well as total adiposity assessed by BMI, the sum of four skinfold thicknesses and skinfold-derived body fat percentage were significantly higher in the ICSI group compared with the SC group, taking into account confounding variables (all P< 0.05). Neither parental nor early life factors could explain the differences.

CONCLUSIONS

We found that pubertal ICSI girls were more prone to central, peripheral and total adiposity compared with their SC counterparts. ICSI adolescents with advanced pubertal stages showed more peripheral adiposity. Continued monitoring of body fat patterns in adolescents born after fertility treatment is mandatory in order to assess their risk for developing obesity and its related adverse health effects in adulthood.

The influence of maternal body mass index on infant adiposity and hepatic lipid content

Maternal overweight and obesity are associated with adverse offspring outcome in later life. The causal biological effectors are uncertain. Postulating that initiating events may be alterations to infant body composition established in utero, we tested the hypothesis that neonatal adipose tissue (AT) content and distribution and liver lipid are influenced by maternal BMI. We studied 105 healthy mother-neonate pairs. We assessed infant AT compartments by whole body MR imaging and intrahepatocellular lipid content by H MR spectroscopy. Maternal BMI ranged from 16.7 to 36.0. With each unit increase in maternal BMI, having adjusted for infant sex and weight, there was an increase in infant total (8 mL; 95% CI, 0.09-14.0; p = 0.03), abdominal (2 mL; 95% CI, 0.7-4.0; p = 0.005), and nonabdominal (5 mL; 95% CI, 0.09-11.0; p = 0.054) AT, and having adjusted for infant sex and postnatal age, an increase of 8.6% (95% CI, 1.1-16.8; p = 0.03) in intrahepatocellular lipid. Infant abdominal AT and liver lipid increase with increasing maternal BMI across the normal range. These effects may be the initiating determinants of a life-long trajectory leading to adverse metabolic health.

Birth weight and subsequent risk of obesity: a systematic review and meta-analysis

This report describes the association between birth weight (BW) and obesity. Screening of 478 citations from five electronic databases resulted in the inclusion of 33 studies, most of medium quality. The meta-analysis included 20 of these published studies. The 13 remaining articles did not provide sufficient dichotomous data and were systematically reviewed, revealing results consistent with the meta-analysis. Our results revealed that high BW (>4000 g) was associated with increased risk of obesity (odds ratio [OR], 2.07; 95% confidence interval [CI], 1.91-2.24) compared with subjects with BW ≤ 4000 g. Low BW (<2500 g) was associated with decreased risk of obesity (OR, 0.61; 95% CI, 0.46-0.80) compared with subjects with BW ≥ 2500 g. However, when two studies exhibited selection bias were removed, the results indicated no significant association between low BW and obesity (OR, 0.77; 95% CI, 0.58-1.04). Sensitivity analyses showed that differences in the study design, sample size and quality grade of the study had an effect on the low BW/obesity association, which low BW was not associated with the risk of obesity in cohort studies, studies with large sample sizes and studies with high quality grades. Pooled results were similar when normal birth weight (2500-4000 g) was used as the reference category. Subgroup analyses based on different growth and developmental stages (pre-school children, school children and adolescents) also revealed that high BW was associated with increased risk of obesity from childhood to early adulthood. No significant evidence of publication bias was present. These results suggest that high BW is associated with increased risk of obesity and may serve as a mediator between prenatal influences and later disease risk.

Evidence for the intra-uterine programming of adiposity in later life

AIM

Research in animals has shown that altering foetal nutrition by under-nourishing or over-nourishing the mother or rendering her diabetic or foetal exposure to glucocorticoids and toxins can programme obesity in later life. The increased adiposity is mediated by permanent changes in appetite, food choices, physical activity and energy metabolism. In humans, increased adiposity has been shown in people who experienced foetal under-nutrition due to maternal famine or over-nutrition due to maternal diabetes. Lower birth weight (a proxy for foetal under-nutrition) is associated with a reduced adult lean mass and increased intra-abdominal fat. Higher birth-weight caused by maternal diabetes is associated with increased total fat mass and obesity in later life. There is growing evidence that maternal obesity, without diabetes, is also a risk factor for obesity in the child, due to foetal over-nutrition effects. Maternal smoking is associated with an increased risk of obesity in the children, although a causal link has not been proven. Other foetal exposures associated with increased adiposity in animals include glucocorticoids and endocrine disruptors.

CONCLUSIONS

Reversing the current obesity epidemic will require greater attention to, and better understanding of, these inter-generational (mother-offspring) factors that programme body composition during early development.

Small birth size, adult overweight, and risk of acute myocardial infraction

BACKGROUND

The association between small size at birth and increased risk of cardiovascular disease in adulthood is well established. This relationship is commonly interpreted according to the "thrifty phenotype hypothesis," which states that the association is generated by a mismatch between fetal and postnatal nutrition. Empirical support for an interaction between impaired fetal growth and later overnutrition is, however, sparse and partly conflicting.

METHODS

The Stockholm Heart Epidemiology Program is a population-based case-control study of risk factors for acute myocardial infarction (MI); data were available for 1058 cases and 1478 controls. Using logistic regression, we studied the effect of size at birth, and its interactive effect with body mass index (BMI), at 3 occasions in adulthood, on the risk of MI. Biologic interaction was estimated with the synergy index.

RESULTS

Very low birth weight for gestational age was associated with increased risk of MI (odds ratio [OR] = 2.0; 95% confidence interval [CI] = 1.4-2.9; attributable fraction = 5%). In nonfatal cases, adjustment for waist-hip ratio, insulin resistance, blood pressure, and lipids reduced the point estimate somewhat. Low birth weight for gestational age in combination with high BMI at the time of the MI produced an OR of 10.8 (3.6-31.8) for MI compared with normal birth weight and normal BMI; the synergy index was 6.5 (95% CI = 1.8-24.0).

CONCLUSIONS

The synergism between small size at birth and high adult BMI supports the thrifty phenotype hypothesis. However, this mechanism seems to pertain to only a small fraction of the acute MI cases, implying minor public health importance.

An evolutionary perspective on the trans-generational basis of obesity

Until recently, obesity was considered the product of interactions between genotype and lifestyle. However, recent work suggests that the genetic heritability of adiposity has been over-estimated, whilst epidemiological studies show that although many genes are associated with nutritional status, the effect of each is very small. A polygenic basis of obesity risk may arise through bet-hedging of numerous traits to accommodate diverse unpredictable environments, rather than through systematic local adaptation. Such 'fragmentation' of the genetic component of metabolism across multiple alleles may be a necessary pre-requisite for complementary enhancement of phenotypic plasticity. The inter-generational component of obesity refers to phenotypic effects transmitted across generations, arising from exposure to maternal, familial and environmental niches during development. Inter-generational transfers of somatic capital (height, lean mass) may respond to ecological conditions through a slow-response damping system, through the influence of maternal phenotype on offspring growth and body composition. The primary traits subject to inter-generational effects may be physique and life history strategy, with adiposity both aiding and responding as a flexible risk management strategy. The biological processes that underpin the offspring's developmental plasticity appear sensitive to the obesogenic niche. Through this sensitivity, diverse environmental factors can induce excess weight gain from childhood onwards.