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

A comparison of maternal and paternal body mass index in early pregnancy

AIM

 To determine the body mass index (BMI) and the body composition of fathers-to-be and to compare the findings with those of mothers-to-be during early pregnancy.

METHODS

 This was a descriptive and comparative study based at a large university teaching hospital. We enrolled men whose partner booked for antenatal care in the first trimester of pregnancy during July 2009. The height and weight of both parents-to-be were measured digitally, and BMI was calculated. The body compositions of the couple were analysed using bioelectrical impedance.

RESULTS

 Of 167 fathers-to-be, 14% were obese (BMI > 29.9 kg/m2 ) compared with 16% of mothers-to-be (NS). However, 50% were overweight (BMI 25.0-29.9 kg/m(2) ) compared with 26% of mothers-to-be (P < 0.001). This may be explained, in part, because the men were on average two years older than the women, and in the men, BMI increased with age. The men had a lower overall fat percentage (P < 0.001), but their visceral fat was higher than in the women (P < 0.001).

CONCLUSION

 Our findings show a high level of obesity in fathers-to-be, which has implications not only for the men themselves but also their families. We suggest that public health interventions directed at obesity during pregnancy should include both parents-to-be.

Obesity-susceptibility loci have a limited influence on birth weight: a meta-analysis of up to 28,219 individuals

BACKGROUND

High birth weight is associated with adult body mass index (BMI). We hypothesized that birth weight and BMI may partly share a common genetic background.

OBJECTIVE

The objective was to examine the associations of 12 established BMI variants in or near the NEGR1, SEC16B, TMEM18, ETV5, GNPDA2, BDNF, MTCH2, BCDIN3D, SH2B1, FTO, MC4R, and KCTD15 genes and their additive score with birth weight.

DESIGN

A meta-analysis was conducted with the use of 1) the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk, Hertfordshire, Fenland, and European Youth Heart Study cohorts (n(max) = 14,060); 2) data extracted from the Early Growth Genetics Consortium meta-analysis of 6 genome-wide association studies for birth weight (n(max) = 10,623); and 3) all published data (n(max) = 14,837).

RESULTS

Only the MTCH2 and FTO loci showed a nominally significant association with birth weight. The BMI-increasing allele of the MTCH2 variant (rs10838738) was associated with a lower birth weight (β ± SE: -13 ± 5 g/allele; P = 0.012; n = 23,680), and the BMI-increasing allele of the FTO variant (rs1121980) was associated with a higher birth weight (β ± SE: 11 ± 4 g/allele; P = 0.013; n = 28,219). These results were not significant after correction for multiple testing.

CONCLUSIONS

Obesity-susceptibility loci have a small or no effect on weight at birth. Some evidence of an association was found for the MTCH2 and FTO loci, ie, lower and higher birth weight, respectively. These findings may provide new insights into the underlying mechanisms by which these loci confer an increased risk of obesity.

Glycemic index and pregnancy: a systematic literature review

Background/Aim. Dietary glycemic index (GI) has received considerable research interest over the past 25 years although its application to pregnancy outcomes is more recent. This paper critically evaluates the current evidence regarding the effect of dietary GI on maternal and fetal nutrition. Methods. A systematic literature search using MEDLINE, EMBASE, CINAHL, Cochrane Library, SCOPUS, and ISI Web of Science, from 1980 through September 2010, was conducted. Results. Eight studies were included in the systematic review. Two interventional studies suggest that a low-GI diet can reduce the risk of large-for-gestational-age (LGA) infants in healthy pregnancies, but one epidemiological study reported an increase in small-for-gestational-age (SGA) infants. Evidence in pregnancies complicated by gestational diabetes mellitus (GDM), though limited (n = 3), consistently supports the advantages of a low-GI diet. Conclusion. There is insufficient evidence to recommend a low-GI diet during normal pregnancy. In pregnancy complicated by GDM, a low-GI diet may reduce the need for insulin without adverse effects on pregnancy outcomes. Until larger-scale intervention trials are completed, a low-GI diet should not replace the current recommended pregnancy diets from government and health agencies. Further research regarding the optimal time to start a low-GI diet for maximum protection against adverse pregnancy outcomes is warranted.

Do physical activity and aerobic fitness moderate the association between birth weight and metabolic risk in youth?: the European Youth Heart Study

OBJECTIVE

Lower birth weight has been associated with a greater risk of metabolic diseases. The aim of this study was examine whether physical activity and aerobic fitness may modify associations between birth weigh and metabolic risk.

RESEARCH DESIGN AND METHODS

The European Youth Heart Study is a population-based study of 9 and 15 year olds (n = 1,254). Birth weight was maternally reported. Skin fold measures were used to calculate body fat and fat mass index (FMI = fat mass [kilograms]/height²). Insulin was measured using fasting blood samples. Physical activity was measured using a hip-worn accelerometer (MTI Actigraph) for >600 min/day for ≥3 days and is expressed as "average activity" (counts per minute) and time spent in above moderate intensity activity (>2000 cpm). Aerobic fitness was assessed using a maximal cycle ergometry test (watts per kilogram fat-free mass).

RESULTS

Higher birth weight was associated with higher FMI (β = 0.49 [95% CI 0.21-0.80]; P = 0.001) and greater waist circumference (0.90 [0.32-1.47]; P < 0.001), adjusted for sex, age-group, sexual maturity, height, and socioeconomic status. Lower birth weight was associated with higher fasting insulin only after further adjustment for adolescent waist circumference and height (-0.059 [-0.107 to -0.011]; P = 0.016). There was no evidence for any modification of the associations after adjustment for physical activity or aerobic fitness.

CONCLUSIONS

The present study did not find any evidence that physical activity or aerobic fitness can moderate the associations among higher birth weight and increased fat mass and greater waist circumference or between lower birth weight and insulin resistance in healthy children and adolescents.

Aerobic fitness and physical activity levels of children born prematurely following randomization to postnatal dexamethasone

OBJECTIVE

To investigate the effects of postnatal dexamethasone treatment on aerobic fitness and physical activity levels in school-aged children born with very low birth weight (VLBW).

STUDY DESIGN

This was a follow-up study of 65 VLBW infants who participated in a randomized controlled trial of dexamethasone (DEX) to reduce ventilator dependency. Aerobic fitness was determined from peak oxygen uptake (VO(2peak)) with a cycle ergometer. Habitual physical activity was assessed by questionnaire.

RESULTS

A trend for a treatment with an interaction between treatment and of diagnosis of chronic lung disease (CLD) was found, with the children in the placebo group with CLD having the lowest VO(2peak) (P = .09). Reduced fitness was seen in 53% of the group treated with DEX and 48% of the group given placebo. No between-group differences in physical activity were seen. Parental reports suggested that nearly two-thirds of the children participated in < 1 hour per week of vigorous physical activity, which was explained in part by decreased large airway function (r = 0.30; P = .03).

CONCLUSIONS

We found no adverse effect of postnatal DEX on aerobic fitness or habitual physical activity at school age. However, the reduced fitness and physical activity levels emphasize the need for closer follow-up and early interventions promoting physical activity to reduce the risk of chronic disease in this at-risk population.

Longitudinal study of prepregnancy cardiometabolic risk factors and subsequent risk of gestational diabetes mellitus: The CARDIA study

This study examined prepregnancy cardiometabolic risk factors and gestational diabetes mellitus (GDM) in subsequent pregnancies. The authors selected 1,164 women without diabetes before pregnancy who delivered 1,809 livebirths between 5 consecutive examinations from 1985 to 2006 in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The authors measured prepregnancy cardiometabolic risk factors and performed multivariate repeated-measures logistic regression to compute the odds of GDM adjusted for race, age, parity, birth order, and other covariates. Impaired fasting glucose (100-125 vs. <90 mg/dL), elevated fasting insulin (>15-20 and >20 vs. <10 μU/mL), and low levels of high-density lipoprotein cholesterol (<40 vs. >50 mg/dL) before pregnancy were directly associated with GDM: The odds ratios = 4.74 (95% confidence interval (CI): 2.14, 10.51) for fasting glucose, 2.19 (95% CI: 1.15, 4.17) for middle insulin levels and 2.36 (95% CI: 1.20, 4.63) for highest insulin levels, and 3.07 (95% CI: 1.62, 5.84) for low levels of high-density lipoprotein cholesterol among women with a negative family history of diabetes; all P < 0.01. Among overweight women, 26.7% with 1 or more cardiometabolic risk factors developed GDM versus 7.4% with none. Metabolic impairment exists before GDM pregnancy in nondiabetic women. Interconceptual metabolic screening could be included in routine health assessments to identify high-risk women for GDM in a subsequent pregnancy and to potentially minimize fetal exposure to metabolic abnormalities that program future disease.

Rapid weight gain during the first year of life predicts obesity in 2-3 year olds from a low-income, minority population

As the prevalence of childhood obesity increases, researchers continue to attempt to identify factors contributing to obesity. The purpose of this study was to define the relationship between birth weight, rapid weight gain (RWG), and early childhood obesity in a low-income, inner-city minority population. In this retrospective chart review, researchers documented every medical encounter recorded in the chart from birth to 3 years for 203 3 year old minority children from low-income families living in an urban area. Based on Center for Disease Control and Prevention's growth charts and tables, z-scores at birth, 4 months, and 1 year were calculated and RWG determined. Researchers determined Body Mass Index percentiles at 3 years of age using the last available weight and height between 24 and 38 months of age. Eight percent of children were underweight, 62% were normal weight, 12% were at overweight and 18% were obese. Children who experienced RWG during the first year of life were 9.24 (CI: 3.73-22.91) as likely to become obese as those who did not experience RWG. Neither low birth weight nor being male increased the odds of becoming obese. Low birth weight predicted underweight at 24-38 months. In this high-risk population, children experiencing RWG during the first year of life have a significantly increased risk of being obese during the preschool years. Future research should identify factors leading to RWG, including specific infant feeding practices.

Association between birth weight and visceral fat in adults

BACKGROUND

Several studies reported inverse associations between birth weight and central adiposity in adults. However, few studies investigated the contributions of different abdominal fat compartments.

OBJECTIVE

We examined associations between birth weight and adult visceral and subcutaneous abdominal fat in the population-based Fenland study.

DESIGN

A total of 1092 adults (437 men and 655 women) aged 30-55 y had available data on reported birth weight, standard anthropometric measures, and visceral and subcutaneous abdominal fat estimated by ultrasound. In a subgroup (n = 766), dual-energy X-ray absorptiometry assessment of total abdominal fat was performed. Linear regression models were used to analyze relations between birth weight and the various fat variables adjusted for sex, age, education, smoking, and body mass index (BMI).

RESULTS

After adjustment for adult BMI, there was an inverse association between birth weight and total abdominal fat [B (partial regression coefficient expressed as SD/1-kg change in birth weight) = -0.09, P = 0.002] and visceral fat (B = -0.07, P = 0.01) but not between birth weight and subcutaneous abdominal fat (B = -0.01, P = 0.3). Tests for interaction showed that adult BMI modified the association between birth weight and visceral fat (P for interaction = 0.01). In stratified analysis, the association between birth weight and visceral fat was apparent only in individuals with the highest BMI tertile (B = -0.08, P = 0.04).

CONCLUSIONS

The inverse association between birth weight and adult abdominal fat appeared to be specific to visceral fat. However, associations with birth weight were apparent only after adjustment for adult BMI. Therefore, we suggest that rapid postnatal weight gain, rather than birth weight alone, leads to increased visceral fat.

[Advances in pathophysiological concepts of obesity]

Obesity is defined as an increase in fat mass, which reflects the inefficiency of the system regulating energy homeostasis to resist against the pressure of environmental and genetic factors. Obesity constitutes itself into several phases to reach a real pathology of adipose tissue, seat of large functional alterations. There is a continuum of obesity forms, from purely genetic forms to purely environmental forms. Within this continuum, genetic and environmental determinants interaction is the rule. The role of gut flora has become a new interesting line of research in the pathophysiology of obesity.

Prevalence of obesity and body mass index correlates in a representative sample of Cretan school children

OBJECTIVE

This study aimed to estimate the prevalence of overweight and obesity and investigate associated factors in a representative sample of Cretan school children.

METHODS

As part of a cross-sectional study in children aged 10-12 years (n = 481, 48% boys) in 27 (urban and rural) schools in Crete, Greece, the rates of overweight and obesity were estimated and multiple logistic regression was used to explore the relationship between several factors and body mass index (BMI).

RESULTS

It was shown that 28% and 13% of children were overweight and obese, respectively. Factors affecting children's BMI classification included: gender (95% CI: 0.21 to 0.56); birth weight (95% CI: 1.33 to 3.46); parental overweight or obesity (95% CI: 1.11 to 6.5 and 95% CI: 4.37 to 30.7 for one and both overweight or obese parents, respectively), paternal educational level (95% CI: 0.89 to 3.48 and 95% CI: 1.49 to 6.13 for low and high educational level, respectively); and cardiovascular fitness levels (95% CI: 0.87 to 0.92).

CONCLUSION

The combined prevalence of overweight and obesity was alarmingly high in the current population (41%); several physiological, behavioural and social factors were shown to affect children's BMI status. These findings highlight the extent of the child obesity problem in Crete and support the need for actions to be taken at a national level to tackle the obesity epidemic.

Placental restriction increases adipose leptin gene expression and plasma leptin and alters their relationship to feeding activity in the young lamb

Low birth weight and catch-up growth predict increased adiposity in children and adults. This may be due in part to leptin resistance, as adults who were born small exhibit increased plasma leptin concentration relative to adiposity. Placental restriction (PR), a major cause of intrauterine growth restriction, reduces size at birth and increases feeding activity and adiposity by 6 wk in sheep. We hypothesized that PR would increase plasma leptin concentration and alter its relationship with feeding activity and adiposity in young lambs. Body size, plasma leptin, feeding activity, adiposity, leptin, and leptin receptor gene expression in adipose tissue were measured (12 control, 12 PR). PR reduced size at birth and increased adiposity. Plasma leptin concentration decreased with age, but to a lesser extent after PR and correlated positively with adiposity similarly in control and PR. PR increased plasma leptin concentration and perirenal adipose tissue leptin expression. Feeding activity correlated negatively with plasma leptin concentration in controls, but positively after PR. PR increases adipose tissue leptin expression and plasma leptin concentration, however, this increased abundance of peripheral leptin does not inhibit feeding activity (suckling event frequency), suggesting PR programs resistance to appetite and energy balance regulation by leptin, leading to early onset obesity.

Familial factors confound the association between maternal smoking during pregnancy and young adult offspring overweight

BACKGROUND

Smoking during pregnancy has been shown to increase the risks of several adverse birth outcomes. Associations with overweight and/or obesity in the offspring have also been suggested. We aim to investigate whether familial factors confound the association between maternal smoking during pregnancy and overweight in early adulthood in young Swedish males born 1983-88.

METHODS

In a population-based Swedish cohort comprising 124 203 singleton males born to Nordic mothers between 1983 and 1988, we examined the association between maternal smoking during pregnancy and the risk of overweight in the offspring at age ∼18 years. We also investigated the association within siblings, controlling for common genes and shared environment.

RESULTS

In the cohort analyses, the risk of overweight was increased in sons of smoking mothers compared with sons of non-smokers: adjusted odds ratios 1.41, 95% confidence interval (CI) 1.34-1.49, and 1.56, 95% CI 1.46-1.66, for one to nine cigarettes per day, and >10 cigarettes per day, respectively. Stratifying for maternal smoking habits across two subsequent male pregnancies, there was an increased risk of overweight for the second son only if the mother was smoking in both male pregnancies. The effect of smoking during pregnancy on the offspring's body mass index was not present when the association was evaluated within full and half sibling pairs.

CONCLUSION

The association between maternal smoking during pregnancy and offspring's risk of overweight appears to be confounded by familial factors.

Effects of childhood body size on breast cancer tumour characteristics

Introduction

Although a role of childhood body size in postmenopausal breast cancer risk has been established, less is known about its influence on tumour characteristics.

Methods

We studied the relationships between childhood body size and tumour characteristics in a Swedish population-based case-control study consisting of 2,818 breast cancer cases and 3,111 controls. Our classification of childhood body size was derived from a nine-level somatotype. Relative risks were estimated by odds ratios with 95% confidence intervals, derived from fitting unconditional logistic regression models. Association between somatotype at age 7 and tumour characteristics were evaluated in a case-only analysis where P values for heterogeneity were obtained by performing one degree of freedom trend tests.

Results

A large somatotype at age 7 was found to be associated with decreased postmenopausal breast cancer risk. Although strongly associated with other risk factors such as age of menarche, adult body mass index and mammographic density, somatotype at age 7 remained a significant protective factor (odds ratio (OR) comparing large to lean somatotype at age 7 = 0.73, 95% confidence interval (CI) = 0.58-0.91, P trend = 0.004) after adjustment. The significant protective effect was observed within all subgroups defined by estrogen receptor (ER) and progesterone receptor (PR) status, with a stronger effect for ER-negative (0.40, 95% CI = 0.21-0.75, P trend = 0.002), than for ER-positive (0.80, 95% CI = 0.62-1.05, P trend = 0.062), tumours (P heterogeneity = 0.046). Somatotype at age 7 was not associated with tumour size, histology, grade or the presence or absence of metastatic nodes.

Conclusions

Greater body size at age 7 is associated with a decreased risk of postmenopausal breast cancer, and the associated protective effect is stronger for the ER-negative breast cancer subtype than for the ER-positive subtype.

Body size at birth and same-sex marriage in young adulthood

An unexplained excess of overweight has been reported among lesbians. In contrast, reports suggest that gay men may be, on average, slightly lighter and shorter than heterosexual men. We studied associations between weight, length, and body mass index (BMI) at birth and same-sex marriage in young adulthood among 818,671 Danes. We used linear regression to calculate differences in mean body measures at birth and Poisson regression analysis to calculate confounder-adjusted incidence rate ratios (IRR) of same-sex marriage according to body measures at birth. Overall, 739 persons entered same-sex marriage at age 18-32 years during 5.6 million person-years of follow-up. Birth year-adjusted mean body measures at birth were similar for same-sex married and other women. However, same-sex marriage rates were 65% higher among women of heavy birth weight (IRR = 1.65; 95% CI = 1.18-2.31, for > or =4000 vs. 3000-3499 g, p = .02), and rates were inversely associated with birth length (p (trend) = .04). For same-sex married men, birth year-adjusted mean weight (-72 g, p = .03), length (-0.3 cm, p = .04), and BMI (-0.1 kg/m(2), p = .09) at birth were lower than for other Danish men. Same-sex marriage rates were increased in men of short birth length (IRR = 1.45; 95% CI = 1.01-2.08, for < or =50 vs. 51-52 cm), although not uniformly so (p (trend) = .16). Our population-based findings suggest that overweight in lesbians may be partly rooted in constitutional factors. Novel findings of smaller average body measures at birth in same-sex marrying men need replication. Factors affecting intrauterine growth may somehow influence sexual and partner-related choices in adulthood.

Childhood obesity and adult cardiovascular disease risk: a systematic review

BACKGROUND

Although the relationship between adult obesity and cardiovascular disease (CVD) has been shown, the relationship with childhood obesity remains unclear. Given the evidence of tracking of body mass index (BMI) from childhood to adulthood, this systematic review investigated the independent relationship between childhood BMI and adult CVD risk.

OBJECTIVE

To investigate the association between childhood BMI and adult CVD risk, and whether the associations observed are independent of adult BMI.

DESIGN

Electronic databases were searched from inception until July 2008 for studies investigating the association between childhood BMI and adult CVD risk. Two investigators independently reviewed studies for eligibility according to inclusion/exclusion criteria, extracted the data and assessed study quality using the Newcastle-Ottawa Scale.

RESULTS

Positive associations between childhood BMI and adult blood pressure or carotid intima-media thickness were generally attenuated once adjusted for adult BMI. Associations between childhood BMI and CVD morbidity/mortality had not been adjusted and do not provide evidence of an independent relationship. Negative associations between childhood BMI and blood pressure were observed in several adjusted data sets.

CONCLUSIONS

Little evidence was found to suggest that childhood obesity is an independent risk factor for CVD risk. Instead, the data suggest that relationships observed are dependent on the tracking of BMI from childhood to adulthood. Importantly, evidence suggests that risk of raised blood pressure is highest in those who are at the lower end of the BMI scale in childhood and overweight in adulthood. The findings challenge the widely accepted view that the presence of childhood obesity is an independent risk factor for CVD and that this period should be a priority for public health intervention. Although interventions during childhood may be important in prevention of adult obesity, it is important to avoid the potential for negative consequences when the timing coincides with critical stages of neurological, behavioural and physical development.

New fetal weight estimation models using fractional limb volume

OBJECTIVES

The main goal of this study was to determine the accuracy and precision of new fetal weight estimation models, based on fractional limb volume and conventional two-dimensional (2D) sonographic measurements during the second and third trimesters of pregnancy.

METHODS

A prospective cross-sectional study of 271 fetuses was performed using three-dimensional ultrasonography to extract standard measurements-biparietal diameter (BPD), abdominal circumference (AC) and femoral diaphysis length (FDL)-plus fractional arm volume (AVol) and fractional thigh volume (TVol) within 4 days of delivery. Weighted multiple linear regression analysis was used to develop 'modified Hadlock' models and new models using transformed predictors that included soft tissue parameters for estimating birth weight. Estimated and observed birth weights were compared using mean percent difference (systematic weight estimation error) and the SD of the percent differences (random weight estimation error). The proportion of newborns with estimated birth weight within 5 or 10% of actual birth weight were compared using McNemar's test.

RESULTS

Birth weights in the study group ranged from 235 to 5790 g, with equal proportions of male and female infants. Six new fetal weight estimation models were compared with the results for modified Hadlock models with sample-specific coefficients. All the new models were very accurate, with mean percent differences that were not significantly different from zero. Model 3 (which used the natural logarithms of BPD, AC and AVol) and Model 6 (which used the natural logarithms of BPD, AC and TVol) provided the most precise weight estimations (random error = 6.6% of actual birth weight) as compared with 8.5% for the best original Hadlock model and 7.6% for a modified Hadlock model using sample-specific coefficients. Model 5 (which used the natural logarithms of AC and TVol) classified an additional 9.1% and 8.3% of the fetuses within 5% and 10% of actual birth weight and Model 6 classified an additional 7.3% and 4.1% of infants within 5% and 10% of actual birth weight.

CONCLUSION

The precision of fetal weight estimation can be improved by adding fractional limb volume measurements to conventional 2D biometry. New models that consider fractional limb volume may offer novel insight into the contribution of soft tissue development to weight estimation.

Risk factors for childhood overweight in offspring of type 1 diabetic women with adequate glycemic control during pregnancy: Nationwide follow-up study in the Netherlands

OBJECTIVE

Pregnancy in type 1 diabetic women remains a high-risk situation for both mother and child. In this study, we investigated long-term effects on body composition, prevalence of overweight, and insulin resistance in children of type 1 diabetic women who had had adequate glycemic control during pregnancy (mean A1C 6.2%), and we related their outcome to perinatal factors, including macrosomia (birth weight >90th percentile).

RESEARCH DESIGN AND METHODS

Anthropometric measurements were performed at 6-8 years of age in 213 offspring of type 1 diabetic mothers who participated in a previous nationwide study. Homeostasis model assessment of insulin resistance (HOMA-IR) was determined from a fasting blood sample in 155 of these children. In addition, we studied BMI standard deviation score (SDS) growth trajectories. Results were compared with national reference data.

RESULTS

The prevalence of overweight in the study population was not different from that in the reference population. However, children who were born macrosomic showed twice as much overweight as nonmacrosomic children. Macrosomia and maternal overweight were independent predictors of childhood overweight. Overweight children showed an increase in BMI SDS starting already after 6 months of age and had a significantly increased HOMA-IR.

CONCLUSIONS

In type 1 diabetic women with adequate glycemic control during pregnancy, long-term effects on body composition and overweight in their offspring at school age are limited and related mainly to macrosomia at birth. Possible targets for prevention of childhood overweight are fetal macrosomia, maternal overweight, and an increase in BMI SDS during the first years of life.

Trends in birth size and macrosomia in Queensland, Australia, from 1988 to 2005

The objectives of this study were to explore temporal changes in birth measures in Queensland, Australia, and examine whether secular trends are similar to those in other countries. This study used data from the Queensland Perinatal Data Collection, including singleton livebirths (n = 831 375) from 1988 to 2005. Recorded birthweight (BW, g), birth length (BL, cm), gestational age (weeks), maternal age, ethnic origin and calculated ponderal index (PI, kg/m(3)) were used. Temporal trends were assessed over the intervals 1988-2005 for BW and 2001-2005 for BW, BL and PI. Mean BW increased during the 17-year interval by approximately 1.9 g/year at a relatively low rate compared with reports from other countries. The proportion of high BW infants (> or = 4000 g) rose by 0.8% per year. Stratification by Indigenous status indicated that the increase in mean BW and prevalence of high BW was confined to non-Indigenous newborns only. The secular increase in BW was further modified by gestational age, and maternal age. The increase in BW was larger in term infants (4.2 g/year) than in preterm infants (1.8 g/year), and larger in infants of younger mothers than in those of older mothers (5.0 g/year vs. 3.1 g/year). There were no trends in mean BL and mean PI at birth from 2001 to 2005. In Queensland, mean BW increased moderately in the last 17 years, as did the proportion of high BW infants. The trend in rising BW remained after controlling for other perinatal characteristics. Birth measures per se and related trends differed by Indigenous status and warrant further investigation.

Family history of diabetes, parental body mass index predict obesity in Latino children

PURPOSE

The purpose of this study is to examine the association between family history of diabetes (FHD), body mass index (BMI), and acculturation with children's BMI status.

METHODS

Baseline data from a randomized community intervention trial promoting healthy eating and physical activity were collected in children living in San Diego, California. A self-administered survey was completed by primary caregivers at each school assessing maternal diabetes, BMI, acculturation, and socioeconomic status (SES). Anthropometric data (height, weight, and BMI) from mothers and children were also collected.

RESULTS

A total of 812 caregivers completed the baseline survey. Adjusting for maternal age, marital status, and socioeconomic level, women who had been diagnosed with diabetes or gestational diabetes or who received diabetes treatment were significantly more likely to have overweight children. Maternal BMI was also associated with children's weight. Maternal acculturation level was marginally associated with children's BMI.

CONCLUSIONS

FHD, gestational diabetes, and BMI were associated with children's overweight status. More comprehensive interventions are needed to prevent obesity in Latino children and adults.

Prevention of overweight and obesity in children under the age of 6 years

Although obesity was rarely observed among children 30 years ago, it is now evident among Canadian children of all ages. Currently, 15.2% of 2- to 5-year-old children are overweight, whereas 6.3% are obese. Limited data suggest that poor dietary and physical activity patterns are increasing obesity risk among these young children. Body weight and lifestyle behaviours are known to track from childhood to adulthood, thereby increasing the risk for obesity and other chronic diseases later in life. Intrauterine life, infancy, and the preschool years may all include critical periods that program the long-term regulation of energy balance, and therefore obesity-prevention strategies should be initiated in utero and continue throughout childhood and adolescence. Although single-strategy obesity-prevention initiatives have had limited success, programs that target multiple behaviours may help reduce body weight and body fat among young children. Parental involvement is key to the success of obesity-prevention programs at a young age, as parents have primary control over their children's food and activity environments. Accordingly, parental obesity is the best predictor of childhood obesity. Parents should be encouraged to teach and role model healthy lifestyle behaviours for their young children. Health professionals can also be involved in obesity prevention, as they are ideally placed to identify young children at risk for obesity. By calculating and plotting the body mass index for all children, and initiating obesity-prevention strategies in utero, health professionals can help curb the rise in overweight and obesity among young children.

Accelerated growth in early life and obesity in preschool Chilean children

In Chile, childhood obesity rates are high. The purpose of this article is to compare BMI growth characteristics of normal (N), overweight (OW), and obese (OB) 5-year olds from 0 to 5 years and explore the influence of some prenatal factors on these patterns of growth. The study was done on a retrospective cohort of 1,089 5-year olds with birth weight >2,500 g. Weight and height were obtained from records at nine occasions (0-36 months); at 52 and 60 months, we measured them. At 60 months, children were classified as N, OW, and OB. At each age, BMI and z-score of BMI (BMI Z) differences were compared among groups. The influence of birth weight, pre-pregnancy BMI, and prenatal variables (weight gain, smoking, and presence of diabetes and preeclampsia) on BMI Z differences between N and OB was also explored. Adiposity rebound (AR) was not observed for the N, although for the OW, it occurred approximately 52 months and for the OB at approximately 24 months. BMI Z differences between N and OB were significant from birth, but were greatest between 6-12 and 36-52 months. Additional adjustment by birth weight, pre-pregnancy BMI, and prenatal variables decreased the BMI Z differences for the first 24 months with virtually no effect after this age. Accelerated growth in OB children from post-transition countries occurs immediately after birth, much earlier than the AR. The influence of prenatal factors on adiposity acquisition may extend at most until 2 years of life, although BMI gains thereafter are more related to postnatal variables.

An obesogenic postnatal environment is more important than the fetal environment for the development of adult adiposity: a study of female twins

BACKGROUND

A relation between birth weight and adult body composition has been reported in singleton populations, especially when more accurate measures of body composition, such as dual-energy X-ray absorptiometry (DXA) were used. It remains uncertain whether this is mediated by a direct effect of fetal nutrition, through factors in the shared environment, or through genetic factors.

OBJECTIVE

The objective was to investigate the relation between birth weight and body composition with the use of a co-twin design.

DESIGN

DXA measurements and birth weights were available for 2228 dizygotic and 842 monozygotic female twins aged between 18 and 80 y. Multivariate regression models were used to identify both individual specific relations and those mediated through the shared environment.

RESULTS

Significant relations were found between birth weight and DXA measures for individuals. A 1-kg increase in birth weight was associated with a 1.72-kg increase in lean mass, a 0.25-kg increase in fat mass, and a 0.05-unit increase in the lean:fat mass ratio. Within twin pairs, the analysis showed that associations between birth weight and absolute levels of lean and fat mass were mediated through individual-specific effects, whereas the relation between birth weight and the proportion of lean to fat mass was mediated purely through factors common to twin pairs.

CONCLUSIONS

A higher birth weight is associated with a higher proportion of lean to fat mass as adults. However, these analyses suggest that this association is not determined by individual specific factors in utero (eg, fetal nutrition) but through factors in the shared common environment of the twins.

Obesity, serious mental illness and antipsychotic drugs

The prevalence of overweight and obesity is higher in people with mental illness than in the general population. Body weight is tightly regulated by a complex system involving the cortex and limbic system, the hypothalamus and the gastrointestinal tract. While there are justifiable concerns about the weight gain associated with antipsychotic medication, it is too simplistic to ascribe all obesity in people with serious mental illness (SMI) to their drug treatment. The development of obesity in SMI results from the complex interaction of the genotype and environment of the person with mental illness, the mental illness itself and antipsychotic medication. There are dysfunctional reward mechanisms in SMI that may contribute to poor food choices and overeating. While it is clear that antipsychotics have profound effects to stimulate appetite, no one receptor interaction provides an adequate explanation for this effect, and many mechanisms are likely to be involved. The complexity of the system regulating body weight allows us to start to understand why some individuals appear much more prone to weight gain and obesity than others.

Getting the message across: mechanisms of physiological cross talk by adipose tissue

Obesity is associated with resistance of skeletal muscle to insulin-mediated glucose uptake, as well as resistance of different organs and tissues to other metabolic and vascular actions of insulin. In addition, the body is exquisitely sensitive to nutrient imbalance, with energy excess or a high-fat diet rapidly increasing insulin resistance, even before noticeable changes occur in fat mass. There is a growing acceptance of the fact that, as well as acting as a storage site for surplus energy, adipose tissue is an important source of signals relevant to, inter alia, energy homeostasis, fertility, and bone turnover. It has also been widely recognized that obesity is a state of low-grade inflammation, with adipose tissue generating substantial quantities of proinflammatory molecules. At a cellular level, the understanding of the signaling pathways responsible for such alterations has been intensively investigated. What is less clear, however, is how alterations of physiology, and of signaling, within one cell or one tissue are communicated to other parts of the body. The concepts of cell signals being disseminated systemically through a circulating "endocrine" signal have been complemented by the view that local signaling may similarly occur through autocrine or paracrine mechanisms. Yet, while much elegant work has focused on the alterations in signaling that are found in obesity or energy excess, there has been less attention paid to ways in which such signals may propagate to remote organs. This review of the integrative physiology of obesity critically appraises the data and outlines a series of hypotheses as to how interorgan cross talk takes place. The hypotheses presented include the "fatty acid hypothesis,", the "portal hypothesis,", the "endocrine hypothesis,", the "inflammatory hypothesis,", the "overflow hypothesis,", a novel "vasocrine hypothesis," and a "neural hypothesis," and the strengths and weaknesses of each hypothesis are discussed.

Maternal anthropometry is associated with the body mass index and waist:height ratio of offspring at 23 years of age

Obesity is considered a public health problem worldwide. Evidence from epidemiologic studies has shown that early undernutrition may be a determinant of obesity later in life. Longitudinal studies are scarce in the setting of low- and middle-income countries. In Pelotas, southern Brazil, a birth cohort has been followed since 1982. Between 2004 and 2005, 4297 members of this cohort were interviewed. The aim of this study is to describe the association between maternal anthropometry and offspring BMI and waist:height ratio (WHtR) at 23 y of age in individuals from the 1982 Pelotas birth cohort. Independent variables included maternal prepregnancy BMI and maternal height, obtained in 1982. The BMI and WHtR of the offspring at 23 y of age were the outcomes. The analysis was stratified by sex and restricted to those cohort members belonging to the lower income group. Multivariable linear regression was adjusted for potential confounding or mediating factors according to a hierarchical framework. For each unit of maternal prepregnancy BMI, the offspring BMI increased 0.65 and 0.63 kg/m(2) in men and women, respectively (P < 0.001). Maternal prepregnancy BMI was directly associated with offspring WHtR in both sexes (P < 0.001). On the other hand, maternal height was not associated with offspring BMI or WHtR. In conclusion, our study suggests that maternal anthropometry is associated with the offspring BMI and WHtR at 23 y of age.

A structural equation model of the developmental origins of blood pressure

BACKGROUND

Birth-size is a problematic proxy for the fetal environment, and regression models testing for associations between birth-size and blood pressure have been criticized.

METHODS

We modelled fetal environment as a latent variable determined by maternal height and arm fat area (AFA) during pregnancy using structural equation modelling. We tested for associations between latent fetal environment (LFE) and systolic blood pressure (SBP) while controlling for birth weight (BW) and current weight (CW). Data are from 1435 male and 1218 female young adult Filipinos (2005; mean age 21 years) enrolled in the Cebu Longitudinal Heath and Nutrition Survey, an ongoing, community-based study of a one-year birth cohort. Using AMOS 6.0, LFE was modelled as a determinant of BW, CW and SBP; CW was modelled as a determinant of SBP.

RESULTS

Overall model fit was excellent (chi2: 32.14, 27 df, P=0.23). The estimated direct relationship between LFE and SBP was inverse for both males ((-0.43) -0.26 (-0.10)) and females ((-0.29) -0.18 (-0.07)).

CONCLUSIONS

These results are consistent with the hypothesis that maternal height and AFA impact fetal development in a manner that is positively associated with fetal growth (as reflected by BW) and inversely associated with SBP in young adulthood.

Influência do crescimento intrauterino restrito sobre a evolução nutricional e crescimento de recém-nascidos pré-termo até a alta hospitalar

OBJETIVO: Analisar o crescimento de recém-nascidos pré-termo (RNPT) com crescimento intrauterino restrito (CIUR) do nascimento até a alta hospitalar. MÉTODOS: Coorte de RNPT provenientes de gestação única, com idade gestacional (IG) de 30 a 34 semanas, Apgar de cinco minutos >6, sem risco infeccioso perinatal e sem malformações. Grupos de estudo: I: CIUR (índice de Kramer=peso ao nascer/peso P50<0,85); II: sem CIUR. Analisaram-se: peso (P), comprimento (C), perímetro cefálico (PC) e índice de massa corpórea (IMC) ao nascimento e à alta ou com 40 semanas de IG corrigida. Análise estatística: comparação de médias (teste t de Student e t pareado), teste do qui-quadrado, correlação de Pearson e regressão linear, sendo significante p<0,05. RESULTADOS: Ao nascimento, houve diferença (p<0,0001) da antropometria entre os 24 RNPT do Grupo I (P=1192g, E=37,7cm, PC=26,9cm) e os 27 do Grupo II (P=2081g, E=43,2cm, PC=30,9cm). À alta, o peso no Grupo II era mais elevado (p=0,03), enquanto C, PC e IMC não diferiram. Do nascimento à alta, P, C e PC aumentaram nos dois grupos. O IMC aumentou de forma significante entre o nascimento e o termo apenas no Grupo I (p<0,0001). Obteve-se correlação inversa entre IMC ao nascimento e diferença do IMC (alta-nascimento): r=-0,79 (p<0,0001) no grupo com CIUR. CONCLUSÕES: CIUR ao nascimento associou-se à elevação do IMC até a alta, que se correlacionou inversamente com o IMC ao nascer, o que sugere um risco maior de obesidade futura nos RNPT com maiores déficits de peso em relação ao comprimento ao nascimento, se essa tendência se mantiver.

Historical cohort studies and the early origins of disease hypothesis: making sense of the evidence

The hypothesis that early-life growth patterns contribute to non-communicable diseases initially emerged from historical cohort studies, consistently associating low birth weight and infant weight gain with later disease risk. Cohort studies offer crucial life-course data on disease aetiology, but also suffer from important limitations, including the difficulty of adjusting for confounding factors and the challenge of interpreting data on early growth. Prospective randomised trials of infant diet appear to provide evidence in direct contradiction to cohort studies, associating faster early growth with disease risk. The present article attempts to resolve this contradiction on two grounds. First, insufficient attention has been directed to inconsistency of outcomes between cohort studies and prospective trials. Cohort studies can assess actual mortality, whereas prospective trials investigate proxies for disease risk. These proxies are often aspects of phenotype that reflect the ‘normalisation’ of metabolism in response to growth, and not all those displaying normalisation in adolescence and early adulthood may go on to develop disease. Second, a distinction is made between ‘metabolic capacity’, defined as organ development that occurs in early life, and ‘metabolic load’, which is imposed by subsequent growth. Disease risk is predicted to be greatest when there is extreme disparity between metabolic capacity and metabolic load. Whereas cohort studies link disease risk with poor metabolic capacity, prospective trials link it with increased metabolic load. Infancy is a developmental period in which nutrition can affect both metabolic capacity and metabolic load; this factor accounts for reported associations of both slow and fast infant growth with greater disease risk.

Impact of infant feeding practices on childhood obesity

Childhood obesity is a complex disease influenced by genetic and environmental factors and their interactions. The current surge in childhood obesity in the United States is attributable to an interaction between a genetic predisposition toward obesity and a permissive environment. Several recent systematic reviews and meta-analyses have been published on the association between breast-feeding and childhood obesity. In these analyses, adjustment for confounding factors attenuated or nullified the protective effect of breast-feeding on later obesity. The Viva La Familia Study was designed to identify genetic and environmental factors affecting obesity and its comorbidities in 1030 Hispanic children from 319 families. Odds ratios for potential risk factors associated with childhood overweight were computed using binary logistic regression for panel data. Early infant-feeding practices were not significant. Salient independent risk factors for childhood obesity in this cohort of Hispanic children were age, birth weight, maternal obesity, paternal obesity, number of children in the family, and the percentage of awake time spent in sedentary activity. Breast-feeding may have a small protective effect against childhood obesity, although residual confounding may exist. Human milk is exquisitely fitted for optimal infant growth and development and may uniquely modulate neuroendocrine and immunologic pathways involved in the regulation of body weight. Nevertheless, other genetic and environmental determinants such as socioeconomic status, parental obesity, smoking, birth weight, and rapid infancy weight gain far supersede infant-feeding practices as risk factors for childhood obesity.

Influence of birth size on body composition in early adulthood: the programming factors for growth and metabolism (PROGRAM)-study

BACKGROUND/OBJECTIVES

Several studies have investigated the relationship of birth size with fat mass and lean body mass (LBM), but the findings differed greatly due to different ways of measuring FM and LBM, different study populations and age groups. We hypothesized that birth size has no influence on adult body composition, whereas weight gain during childhood has.

METHODS

In the programming factors for growth and metabolism (PROGRAM)-study, a cohort of 312 young adults, aged 18-24 years, FM and LBM were determined by dual energy X-ray absorptiometry (DXA). Subsequently, differences in FM and LBM were analysed in four subgroups, young adults either born small for gestational age with short stature (SGA-S) or with catch-up growth (SGA-CU), or born appropriate for gestational age (AGA) with idiopathic short stature (ISS) or with normal stature (controls).

RESULTS

Age, gender, adult height SDS and adult weight SDS were significant positive determinants of FM and LBM, whereas weight gain during childhood was positively significant for FM and negatively for LBM. Birth weight SDS tended to be significant and birth length SDS was not. Weight gain during childhood was positively correlated with waist : hip ratio and trunk fat : total fat ratio. SGA-CU subjects had significantly higher FM and significantly lower LBM than controls.

CONCLUSION

Weight gain during childhood is an important determinant of body composition in young adulthood, whereas birth size is less important. In clinical practice, too much weight gain in childhood should be prevented as it results in a relatively high fat mass, especially in children with catch-up growth in weight, like SGA-CU subjects.

Gross placental measures and childhood growth

OBJECTIVES

We hypothesised that the gross placental measures would be positively associated with childhood growth.

METHODS

We analysed data on 23,967 mother-infant pairs enrolled in the Collaborative Perinatal Project. In race-stratified regression models, the main outcomes were birthweight and z-score body-mass index (BMI) at ages 4 and 7.

RESULTS

Some placental measures were significantly associated with z-score BMI at age 7: in Blacks, placental weight (beta = 0.0004/g; 95%CI: 0.0001, 0.0008), chorionic plate area (beta = 0.0007; 95%CI: 0.0001, 0.0012) and largest diameter (beta = 0.013; 95%CI: 0.004, 0.026); and in Whites placental weight (beta = 0.0004/g; 95%CI: 0.0001, 0.0003) and largest diameter (Model 3: beta = 0.020; 95%CI: 0.007, 0.032). Tested as group, placental measures significantly predicted z-score BMI at age 7 (all p values < 0.005).

CONCLUSIONS

Placental structure independently predicts birthweight and childhood growth. Strategies to improve placental structure might favourably influence birthweight and childhood development.

Prevalence and correlates of the metabolic syndrome in a population-based sample of European youth

BACKGROUND

Until recently, there has been no unified definition of the metabolic syndrome (MetS) in the youth. Therefore, the prevalence of MetS and its association with potential correlates are largely unknown.

OBJECTIVE

The objective was to quantify the prevalence, identify the correlates, and examine the independent associations between potential correlates with MetS.

DESIGN

A population-based cohort study was conducted in 10- and 15-y-old youth from Estonia, Denmark, and Portugal (n = 3193). MetS was defined according to the International Diabetes Federation. Correlates included maternal socioeconomic status, body mass index (BMI), hypertension, and prevalent diabetes and maternally reported child's birth weight and duration of breastfeeding. Data on sexual maturity, objectively measured physical activity, cardiorespiratory fitness, self-reported sports participation, television viewing, and regular play were collected for the children.

RESULTS

The prevalence of MetS was 0.2% and 1.4% in 10- and 15-y-olds, respectively. Cardiorespiratory fitness (standardized odds ratio: 0.33; 95% CI: 0.15, 0.75), physical activity (standardized odds ratio: 0.40; 95% CI: 0.18, 0.88), and maternal BMI (standardized odds ratio: 1.61; 95% CI: 1.11, 2.34) were all independently associated with MetS after adjustment for sex, age group, study location, birth weight, and sexual maturity. An increase in daily moderate-intensity physical activity by 10-20% was associated with a 33% lower risk of being categorized with MetS.

CONCLUSIONS

High maternal BMI and low levels of cardiorespiratory fitness and physical activity independently contribute to the MetS and may be targets for future interventions. Relatively small increases in physical activity may significantly reduce the risk of MetS in healthy children.

Dietary supplementation of rural Gambian women during pregnancy does not affect body composition in offspring at 11-17 years of age

Fetal nutrition is thought to be an important determinant of later disease risk, although evidence from randomized-controlled trials in humans is lacking. We followed children born during a protein-energy supplementation trial to investigate to what extent this maternal supplement, which improved birth weight, influenced offspring body composition in adolescence. Subjects were 1270 Gambian children (659 boys, 611 girls) aged 11-17 y whose mothers had participated in the original cluster-randomized trial and had received the supplement during pregnancy (intervention) or postpartum (control). Basic anthropometry was measured using standard techniques and fatness was assessed by bioelectrical impedance analysis and population-specific prediction equations. For boys, mean body fat was 12.6% for both intervention and control groups. Mean trunk fat was 11.9% in the intervention group and 12.0% in the control. Intervention girls had a mean body fat of 19.5% and trunk fat of 15.2%; for control girls, it was 19.3 and 14.8%, respectively. BMI, body fat, trunk fat, fat mass index, and fat-free mass index did not differ for either sex when analyzed with generalized estimating equations adjusted for age, maternal height, maternal parity, location, season of birth, and menarche in females. Neither infant-attained size nor the onset of menarche were affected by maternal supplementation. These findings suggest that protein-energy supplements to pregnant women, compared with lactating women, do not affect offspring body composition during adolescence.

Pediatric Obesity: It's Time for Prevention before Conception Can Maternal Obesity Program Pediatric Obesity?

Global increases in obesity have led public health experts to declare this disease a pandemic. Although prevalent in all ages, the dire consequences associated with maternal obesity have a pronounced impact on the long-term health of their children as a result of the intergenerational effects of developmental programming. Previously, fetal under-nutrition has been linked to the predisposition to pediatric obesity explained by the adiposity rebound and ‘catch-up’ growth that occurs when a child born to a nutrient deprived mother is exposed to the obesogenic environment of present day. Given the recent increase in maternal overweight/obesity (OW/OB) our attention has shifted from nutrient restriction to overabundance and excess during pregnancy. Consideration must now be given to interventions that could mitigate pregravid body mass index (BMI), attenuate gestational weight gain (GWG) and reduce postpartum weight retention (PPWR) in an attempt to prevent the downstream signaling of pediatric obesity and halt the intergenerational cycle of weight related disease currently plaguing our world. Thus, this paper will briefly review current research that best highlights the proposed mechanisms responsible for the development of child OW/OB and related sequalae (e.g. type II diabetes (T2D) and cardiovascular disease (CVD)) resulting from maternal obesity.

Season of birth and prevalence of overweight and obesity in Canada

BACKGROUND

The contexts of prenatal life, such as one's season of birth, have been shown to influence health later in life. For example, research has shown a disproportionate number of schizophrenic patients are born during the late winter and early spring. The purpose of this study was to examine season of birth as a possible risk for overweight and obesity.

METHODOLOGY

Utilizing cycle 2.1 of the Canadian Community Health Survey, birth data of respondents 12 to 64 years old were examined. The risk associated with season of birth was compared to risks previously identified for overweight and obesity (e.g. physical inactivity, low socioeconomic status etc.).

RESULTS

Overall, among the 20-64 year olds, those in the obese III (BMI> or =40 kg/m(2)) category were 1.54 times more likely to be born in the winter (95% CI: 1.21-1.95). This effect appears largely due to a winter/spring season of birth effect among the obese II/III (BMI> or =35) 20-29 y cohort (Winter OR: 1.53, 95% CI: 1.08-2.18; Spring OR: 1.55, 95% CI: 1.10-2.18). A summer season of birth effect was observed for the obese II/III 40-49 y cohort (OR: 1.59, 95% CI: 1.21-2.11). No season of birth effects were observed among any BMI categories for those 12-19 years, or among those 20 y and over in the overweight BMI category.

CONCLUSION

A greater proprtion of class III obese Canadians are born during the winter/spring, particularly in the 20-29 y age cohort. However, other factors (e.g. physical inactivity) represent greater risks for obesity than season of birth.

Maternal type 1 diabetes reduces the risk of islet autoantibodies: relationships with birthweight and maternal HbA(1c)

AIMS/HYPOTHESIS

The risk of type 1 diabetes is reduced in the children of mothers with type 1 diabetes compared with children of fathers with type 1 diabetes. We asked whether children of mothers with type 1 diabetes also have a decreased risk of developing islet autoantibodies, and which factors associated with maternal diabetes contribute to a reduced islet autoantibody risk in offspring.

METHODS

Singleton offspring of a mother (n = 1,008) or father with type 1 diabetes (n = 578) from the BABYDIAB study were included. Children were followed from birth for the development of islet autoantibodies defined as two or more autoantibodies to insulin, glutamic acid decarboxylase or insulinoma antigen 2 in two or more blood samples.

RESULTS

Islet autoantibody risk was lower in children of mothers with type 1 diabetes (5 year risk, 3.2% vs 5.7% in children of fathers with type 1 diabetes; p = 0.04). Among factors that differed between pregnancies from mothers with and without type 1 diabetes, birthweight was associated with islet autoantibody risk. Risk was reduced in children with birthweights in the lower (adjusted HR 0.33; 95% CI 0.14-0.75; p = 0.009) and upper (HR 0.45; 95% CI 0.21-0.97; p = 0.04) tertiles compared with the middle tertile. A sub-analysis of maternal HbA(1c) suggested that moderately elevated third trimester maternal HbA(1c) was also associated with a reduced islet autoantibody risk in children of mothers with type 1 diabetes (5.7-7%; HR 0.38; 95% CI 0.15-0.96; p = 0.04 vs children of mothers with HbA(1c) < 5.7%).

CONCLUSIONS/INTERPRETATION

The risk of islet autoimmunity is modified by maternally influenced events such as birthweight.

Adiposity and height of adult Hmong refugees: relationship with war-related early malnutrition and later migration

This study investigated whether historical proxies for poor nutrition early in life were associated with differences in body composition and height among adult Hmong refugees. Life history and anthropometric data were collected from a sample of 279 Hmong aged 18-51 years who were born in Laos or Thailand and resettled in French Guiana or the United States following the Second Indochina War. Overall, 30.5% were born in a war zone in Laos, while 38.8% were displaced as infants; these individuals were presumed to have experienced malnutrition in the perinatal and infant periods, respectively. Resettlement in urban areas in the US was utilized as a proxy for greater exposure to excessive energy balance, compared with Hmong who resettled in rural areas in French Guiana. In multiple linear regression models, being displaced in infancy was negatively associated with height after controlling for confounders, while being born in a war zone was associated with higher adiposity and centralized body fat distribution. Resettlement in the US was associated with a higher centralization of subcutaneous fat, but not overall adiposity. These findings may be of interest to the study of the developmental origins of obesity, in a population that has undergone early malnutrition followed by migration and rapid nutritional transition.

Hypothalamic substrates of metabolic imprinting

The mammalian brain develops according to intrinsic genetic programs that are influenced by a variety of environmental factors. Developing neural circuits take shape in two major environments: one in utero and a second during postnatal life. Although an abundance of epidemiological and experimental evidence indicates that nutritional variables during perinatal life have a lasting effect on metabolic phenotype, the underlying mechanisms remain unclear. Peripheral hormones are widely regarded as effective signals that reflect the state of peripheral environments and can directly influence the development of a variety of functional neural systems. Recent findings suggest that the adipocyte-derived hormone leptin may play an important role in directing formation of hypothalamic neural pathways that control body weight. The arcuate nucleus of the hypothalamus (ARH) is a key site for the regulatory actions of leptin in adults, and this same hormone is required for the normal development of ARH projections to other parts of the hypothalamus. In this review, the neurobiological role of leptin is considered within the context of hypothalamic development and the possibility that variations in both prenatal and postnatal nutritional environments may impact development of neural circuits that control energy metabolism through an indirect action on leptin secretion, or signaling, during key developmental critical periods.

Maternal and child undernutrition: consequences for adult health and human capital

In this paper we review the associations between maternal and child undernutrition with human capital and risk of adult diseases in low-income and middle-income countries. We analysed data from five long-standing prospective cohort studies from Brazil, Guatemala, India, the Philippines, and South Africa and noted that indices of maternal and child undernutrition (maternal height, birthweight, intrauterine growth restriction, and weight, height, and body-mass index at 2 years according to the new WHO growth standards) were related to adult outcomes (height, schooling, income or assets, offspring birthweight, body-mass index, glucose concentrations, blood pressure). We undertook systematic reviews of studies from low-income and middle-income countries for these outcomes and for indicators related to blood lipids, cardiovascular disease, lung and immune function, cancers, osteoporosis, and mental illness. Undernutrition was strongly associated, both in the review of published work and in new analyses, with shorter adult height, less schooling, reduced economic productivity, and--for women--lower offspring birthweight. Associations with adult disease indicators were not so clear-cut. Increased size at birth and in childhood were positively associated with adult body-mass index and to a lesser extent with blood pressure values, but not with blood glucose concentrations. In our new analyses and in published work, lower birthweight and undernutrition in childhood were risk factors for high glucose concentrations, blood pressure, and harmful lipid profiles once adult body-mass index and height were adjusted for, suggesting that rapid postnatal weight gain--especially after infancy--is linked to these conditions. The review of published works indicates that there is insufficient information about long-term changes in immune function, blood lipids, or osteoporosis indicators. Birthweight is positively associated with lung function and with the incidence of some cancers, and undernutrition could be associated with mental illness. We noted that height-for-age at 2 years was the best predictor of human capital and that undernutrition is associated with lower human capital. We conclude that damage suffered in early life leads to permanent impairment, and might also affect future generations. Its prevention will probably bring about important health, educational, and economic benefits. Chronic diseases are especially common in undernourished children who experience rapid weight gain after infancy.

Follow-up of GK rats during prediabetes highlights increased insulin action and fat deposition despite low insulin secretion

The adult Goto-Kakizaki (GK) rat is characterized by impaired glucose-induced insulin secretion in vivo and in vitro, decreased beta-cell mass, decreased insulin sensitivity in the liver, and moderate insulin resistance in muscles and adipose tissue. GK rats do not exhibit basal hyperglycemia during the first 3 wk after birth and therefore could be considered prediabetic during this period. Our aim was to identify the initial pathophysiological changes occurring during the prediabetes period in this model of type 2 diabetes (T2DM). To address this, we investigated beta-cell function, insulin sensitivity, and body composition in normoglycemic prediabetic GK rats. Our results revealed that the in vivo secretory response of GK beta-cells to glucose is markedly reduced and the whole body insulin sensitivity is increased in the prediabetic GK rats in vivo. Moreover, the body composition of suckling GK rats is altered compared with age-matched Wistar rats, with an increase of the number of adipocytes before weaning despite a decreased body weight and lean mass in the GK rats. None of these changes appeared to be due to the postnatal nutritional environment of GK pups as demonstrated by cross-fostering GK pups with nondiabetic Wistar dams. In conclusion, in the GK model of T2DM, beta-cell dysfunction associated with increased insulin sensitivity and the alteration of body composition are proximal events that might contribute to the establishment of overt diabetes in adult GK rats.

Long-term adverse outcomes of low birth weight, increased somatic growth rates, and alterations of body composition in the premature infant: review of the evidence

In appropriate-for-gestational-age preterm infants, data are reviewed to support that both high and low nutrient intakes, as well as fast or slow rates of growth in the neonatal intensive care unit, have long-term adverse (or even positive) effects on body weight and the metabolic syndrome later in life. Though more studies are needed, it is concluded that it is likely that any such effects will be relatively small compared with other risk factors such as parental weight and various lifestyle factors. At the present time, there is little evidence that negates the goal of maximizing nutritional support for the very low birth weight infant in the neonatal period.

Child and adolescent obesity: epidemiology and developmental perspectives

From infancy through adolescence, more and more children are becoming overweight. National prevalence data show that more than 17% of youth have a body mass index (BMI) above the 95th percentile of the US age and sex-specific reference. Particularly alarming are rates in children as young as 2 years of age, and among minority children. Periods of heightened vulnerability to weight gain have been identified, and research supports the notion that obesity has its origins in early life. This paper focuses on susceptibility to increased adiposity during the prenatal period, infancy, mid-childhood and adolescence, and how factors operating in each of these periods influence risk of becoming overweight. Prenatal exposure to over or undernutrition, rapid growth in early infancy, an early adiposity rebound in childhood, and early pubertal development have all been implicated in the development of obesity. The persistence of obesity from young ages emphasizes the importance of understanding growth trajectories, and of developing prevention strategies to overcome strong influences of obesigenic environments at young ages.