Early growth and cardiovascular disease

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.

Current perspectives of insulin resistance and polycystic ovary syndrome

AIMS

To review the relationship between insulin resistance and polycystic ovary syndrome.

METHODS

A literature review.

RESULTS

Insulin resistance likely plays a central pathogenic role in polycystic ovary syndrome and may explain the pleiotropic presentation and involvement of multiple organ systems. Insulin resistance in the skeletal muscle of women with polycystic ovary syndrome involves both intrinsic and acquired defects in insulin signalling. The cellular insulin resistance in polycystic ovary syndrome has been further shown to involve a novel post-binding defect in insulin signal transduction. Treatment of insulin resistance through lifestyle therapy or with a diabetes drug has become mainstream therapy in women with polycystic ovary syndrome. However, effects with current pharmacologic treatment with metformin tend to be modest, with limited benefit as an agent to treat infertility. Insulin resistance contributes to increased risk for pregnancy complications, diabetes and cardiovascular disease risk profile in polycystic ovary syndrome, which is further exacerbated by obesity. While numerous studies demonstrate increased prevalence of cardiovascular disease risk factors in women with polycystic ovary syndrome, there are limited data showing that women with polycystic ovary syndrome are at increased risk for cardiovascular disease events.

CONCLUSIONS

Insulin resistance is linked to polycystic ovary syndrome. Further study of lifestyle and pharmacologic interventions that reduce insulin resistance, such as metformin, are needed to demonstrate that they are effective in reducing the risk of diabetes, endometrial abnormalities and cardiovascular disease events in women with polycystic ovary syndrome.

Pode o peso ao nascer influenciar o estado nutricional, os níveis de atividade física e a aptidão física relacionada à saúde de crianças e jovens?

A aptidão física relacionada à saúde é definida como um conjunto de atributos fisiológicos que o indivíduo apresenta para o desempenho de atividades físicas diárias sem fadiga excessiva. Sabe-se que fatores como atividade física e estado nutricional influenciam diretamente os níveis de aptidão física. Entretanto, o aporte adequado de nutrientes nos períodos iniciais da vida é determinante para o crescimento e o desenvolvimento de órgãos e de sistemas. O peso ao nascer está relacionado ao desenvolvimento intrauterino bem como à prevalência de doenças cardiovasculares e metabólicas. Recentemente o peso ao nascer tem sido associado aos níveis de aptidão física relacionada à saúde. O mecanismo subjacente pode estar relacionado aos efeitos decorrentes de insultos ocorridos no período crítico do desenvolvimento, com alterações no padrão de eventos celulares. As consequências estão na aquisição de padrões fisiológicos maduros do organismo e na ocorrência de eventos metabólicos, com prejuízo na aptidão física. O presente estudo propõe uma análise sobre a aptidão física relacionada à saúde e sua relação com a atividade física, o estado nutricional e com o peso ao nascer do indivíduo. Os termos de indexação utilizados foram: physical fitness, programming, physical activity, nutritional status e low birth weight. Concluiu-se que indivíduos nascidos com baixo peso apresentam alterações no estado nutricional com consequências negativas para a atividade física e aptidão física relacionada à saúde.

Longitudinal body composition data in exclusively breast-fed infants: a multicenter study

Reference %fat and total fat-free mass data is necessary for evaluating growth in infants. We aimed to develop longitudinal %fat and total fat-free mass data in infants from birth to 6 months of age. An observational, multicenter, prospective cohort study was conducted with assessments at birth, 1 week, 2 weeks, 1, 2, 3, 4, 5, and 6 months of age. Subjects were exclusively breast-fed and were enrolled at three centers. Whole-body composition (i.e., % fat and total fat-free mass) were assessed using air-displacement plethysmography (ADP) (PEA POD; Life Measurement, Concord, CA). Maternal prepregnancy BMI, gestational weight gain, and infant anthropometric data were collected. A total of 160 infants (boys = 84) were assessed from birth to 4 months of age. Mean birth weight was 3.46 ± 0.39 kg % fat and fat-free mass significantly increased from birth to 4 months of age (P < 0.0001). Gender-specific %fat and total fat-free mass curves for infants from birth to 4 months of age were created. This study will be beneficial to health-care professionals in evaluating normal growth and nutritional patterns in the first months of life.

Quality of growth in exclusively breast-fed infants in the first six months of life: an Italian study

Nutrition in early life, growth, and subsequent health over a lifetime are significantly interrelated. The aim of this study was to assess body composition changes in exclusively breast-fed infants from birth up to 6 mo of age. An observational, prospective, cohort study was conducted. Fifty-nine full-term, healthy, exclusively breast-fed infants underwent assessment of growth and body composition, using air-displacement plethysmograph (i.e. PEA POD) by Life Measurement, Inc. (Concord, CA). Body composition was assessed at birth, 2 wk, and 1, 2, 3, 4, 5, and 6 mo of age. Mean birth weight (g) and gestational age (wk) of the infants were 3170 ± 420 and 39.21 ± 1.29, respectively. Percentage of fat mass increased significantly over the first 4 mo (p < 0.001), both in boys and girls, with no differences detected between boys and girls at any time point. This article provides preliminary in-depth data on whole-body composition, in exclusively breast-fed infants during the first months of life. Further studies assessing larger sample sizes are desirable to develop reference body composition data.

A meta-analysis of depression during pregnancy and the risk of preterm birth, low birth weight, and intrauterine growth restriction

CONTEXT

Maternal depressive symptoms during pregnancy have been reported in some, but not all, studies to be associated with an increased risk of preterm birth (PTB), low birth weight (LBW), and intrauterine growth restriction (IUGR).

OBJECTIVE

To estimate the risk of PTB, LBW, and IUGR associated with antenatal depression.

DATA SOURCES AND STUDY SELECTION

We searched for English-language and non-English-language articles via the MEDLINE, PsycINFO, CINAHL, Social Work Abstracts, Social Services Abstracts, and Dissertation Abstracts International databases (January 1980 through December 2009). We aimed to include prospective studies reporting data on antenatal depression and at least 1 adverse birth outcome: PTB (<37 weeks' gestation), LBW (<2500 g), or IUGR (<10th percentile for gestational age). Of 862 reviewed studies, 29 US-published and non-US-published studies met the selection criteria.

DATA EXTRACTION

Information was extracted on study characteristics, antenatal depression measurement, and other biopsychosocial risk factors and was reviewed twice to minimize error.

DATA SYNTHESIS

Pooled relative risks (RRs) for the effect of antenatal depression on each birth outcome were calculated using random-effects methods. In studies of PTB, LBW, and IUGR that used a categorical depression measure, pooled effect sizes were significantly larger (pooled RR [95% confidence interval] = 1.39 [1.19-1.61], 1.49 [1.25-1.77], and 1.45 [1.05-2.02], respectively) compared with studies that used a continuous depression measure (1.03 [1.00-1.06], 1.04 [0.99-1.09], and 1.02 [1.00-1.04], respectively). The estimates of risk for categorically defined antenatal depression and PTB and LBW remained significant when the trim-and-fill procedure was used to correct for publication bias. The risk of LBW associated with antenatal depression was significantly larger in developing countries (RR = 2.05; 95% confidence interval, 1.43-2.93) compared with the United States (RR = 1.10; 95% confidence interval, 1.01-1.21) or European social democracies (RR = 1.16; 95% confidence interval, 0.92-1.47). Categorically defined antenatal depression tended to be associated with an increased risk of PTB among women of lower socioeconomic status in the United States.

CONCLUSIONS

Women with depression during pregnancy are at increased risk for PTB and LBW, although the magnitude of the effect varies as a function of depression measurement, country location, and US socioeconomic status. An important implication of these findings is that antenatal depression should be identified through universal screening and treated.

Impact of maternal undernutrition on diabetes and cardiovascular disease risk in adult offspring

Epidemiological, clinical, and experimental observations have led to the hypothesis that the risk of developing chronic diseases in adulthood is influenced not only by genetic and adult lifestyle factors, but also by environmental factors during early life. Low birth weight, a marker of intrauterine stress, has been linked to predisposition to cardiovascular disease (CVD) and diabetes. The compelling animal evidence and significant human data to support this conclusion are reviewed. Specifically, the review discusses the role of maternal nutrition before and during pregnancy, placental insufficiencies and epigenetic changes in the increased predisposition to diabetes and CVD in adult life. The impact of low birth weight and catch-up growth as they pertain to risk of disease in adult life is also discussed. In addition, adult disease risk in the overnourished fetus is also mentioned. Reference is made to some of the mechanisms of the induction of diabetes and CVD phenotype. It is proposed that fetal nutrition, growth and development through efficient maternal nutrition before and during pregnancy could constitute the basis for nutritional strategies for the primary prevention of diabetes and CVD.

Small birth weight and later body composition and fat distribution in adolescents: the Avena study

OBJECTIVE

To assess the association between birth weight and body composition and fat distribution in adolescents, and to test the possible sex-specific effect in these relationships.

METHODS AND PROCEDURES

A total of 1,223 adolescents 13-18.5 years old (553 male adolescents and 670 female adolescents) born at >35 weeks, were selected from a cross-sectional multicenter study conducted in five Spanish cities in 2000-2002. BMI was calculated from weight and height. Triceps and subscapular skinfold thickness (ST) were measured on the left side, and fat mass (FM) and fat-free mass (FFM) were estimated according to the equations of Slaughter et al. Subscapular skinfold adjusted by tricipital (ST) and waist circumference were used as markers of central adiposity.

RESULTS

Birth weight Z-score was positively associated with FFM in female adolescents (P<0.001), but not in male adolescents, after controlling for age, pubertal stage, gestational age, socioeconomic status, physical activity, and current height (P<0.001 for interaction between adjusted birth weight Z-score and sex). Adjusted birth weight Z-score was inversely associated with central adiposity in male and female adolescents as measured by ST (P=0.026).

DISCUSSION

These results provide further evidence that gender has an important influence on the programming effect of birth weight on later FFM in adolescents because the effect was only observed in female adolescents. Our results suggest that small size for gestational age at birth could program more central subcutaneous fat deposition in adolescents of both sexes, but further research is needed on this issue.

Physical growth of preterm girls with visual impairment

The aim of this study was to estimate pubertal age and to assess the level of physical development of preterm girls with defective vision. The study material - anthropometric data (body height and weight, BMI) and information on the age of menarche were collected from 155 subjects with defective vision (partially sighted and blind). Median age at menarche was estimated by probit analysis. The girls, ranging in age from 7-18 years, attended Centers for Blind and Partially Sighted Children in Wroclaw and Cracow (Poland). 22% of the subjects were prematurely born, were born with low birth mass and their sight defect diagnosed as retinopathy due to prematurity (ROP). The girls with ophthalmic impairments were shorter and lighter than their age peers from the reference data. Blind girls reached pubertal age 2 months earlier than the partially sighted (Me=13.31 and Me=13.44) and, the preterm subjects entered puberty 6 months earlier than the full-term girls, irrespective of degree of defect (Me=12.93 and Me=13.42, respectively). The results suggest that earlier puberty is associated with visual impairment. The results show also that irrespective of the degree of defect, preterm girls reach menarche significantly earlier than those who were full-term. It seems possible that mechanisms responsible for earlier puberty in the preterm subjects and with low body mass play an important a role in sexual maturation in girls with sight dysfunction. There appears to be a need to pursue further studies in this sphere.

Effect of the Ala12 allele in the PPARgamma-2 gene on the relationship between birth weight and body composition in adolescents: the AVENA study

The intent of this study was to assess whether the effect of birth weight on later body composition is modified by Pro12Pro, Pro12Ala, and Ala12Ala genotypes of the peroxisome proliferator-activated receptor gamma-2 (PPARgamma-2) gene. The PPARgamma-2 gene polymorphism was genotyped in 273 adolescents aged 13-18.5 y, born at term and whose birth weight was known. They were selected from a cross-sectional multicenter study conducted in five Spanish cities in 2000-2002. Body mass index (BMI) was calculated from weight and height measurements, and body composition and fat distribution were estimated from skinfold thickness. A total of 229 subjects (111 males and 118 females) carried the Pro12Pro genotype and 44 (22 males and 22 females) the Pro12Ala and Ala12Ala PPARgamma-2 genotypes. In the Pro12Pro group, birth weight Z score was positively associated with both fat-free mass (FFM) (p < 0.05) and fat mass (FM) (p < 0.05), but these relationships disappeared after controlling for age, gestational age, socioeconomic status (SES), physical activity, Tanner stage, sex, and BMI. In the Ala12 group, birth weight Z score was positively associated with FFM (p < 0.01), and this relationship remained significant after controlling for confounding variables (p < 0.05). Small body weight at birth may program lower FFM in adolescents carrying the Ala12 allele in the PPARgamma-2 gene.

Probiotics for necrotizing enterocolitis: a systematic review

BACKGROUND

Necrotizing enterocolitis (NEC) is the most commonly acquired neonatal intraabdominal emergency and causes significant morbidity and mortality. A proposed strategy for the prevention of NEC is the administration of oral probiotics. Probiotics have been shown to reduce NEC in experimental rat models and have been used in clinical trials. The authors aimed to review the existing data on the use of oral probiotics for the prevention of NEC in preterm infants (age <33 weeks) and those with very low birth weight (VLBW).

MATERIALS AND METHODS

Systematic review of randomized controlled trials (RCTs) and quasi-RCTs was performed to find outcome measures of incidence, severity, need for surgery, and mortality in NEC. Electronic searches were performed on Medline and CINAHL databases using key word and subject headings with combinations of the terms "infant, preterm"; "infant, VLBW"; "enterocolitis, necrotizing"; and "probiotics." In addition, citation searches were performed for all potential studies.

RESULTS

Six potential RCTs were identified for inclusion, but there were no systematic or Cochrane database reviews identified. One study was discounted because of the use of historical controls, so 5 studies were selected for analysis. Cumulatively, 640 infants were treated with probiotics and 627 were used as control subjects. All of the studies showed a trend toward less NEC in the treatment group. The heterogeneity of probiotic formulations and the timing and methods of interventions in the identified studies made synthesis and comparison of data inappropriate.

CONCLUSIONS

The data appear to lend support to the use of oral probiotics for the prevention of NEC in preterm infants and those with VLBW. However, the data are insufficient to comment on their short- and long-term safety. Type of probiotics used, as well as the timing and dosage, are still to be optimized. Further understanding of the pathogenesis of NEC and the mechanisms by which probiotics prevent it may lead to evidence-based treatment strategies.

Validity of maternal report on birth weight 11 years after delivery: the 1993 Pelotas Birth Cohort Study, Rio Grande do Sul State, Brazil

Birth weight has short and long-term effects on health. Some studies have used retrospective data on birth weight, reported by the subject or by the parents. This paper compares data on birth weight measured by the research team in 1993 with birth weight reported by the mother in 2004-2005, using data from the 1993 Pelotas Birth Cohort Study, Rio Grande do Sul State, Brazil. We also evaluate the role of misclassification when exploring the effect of birth weight on a given outcome. Mean difference between the two variables was 20g (SD = 288.3). Agreement for detecting low birth weight was 95.2% in the sample as a whole (kappa = 0.73), but was lower among low-schooling mothers. Mothers of children weighing less than 3,500g at birth tended to overestimate the child's birth weight. Inversely, mothers of heavier children tended to underestimate the values. One out of four mothers reported a difference of at least 200g in birth weight as compared to that measured in 1993. Use of reported birth weight diluted the magnitude of the association with body mass index at 11 years in comparison with measured birth weight. Reported birth weight should be used with great caution, if at all.

Gender-based differences in endocrine and reproductive toxicity

Basic differences in male versus female reproductive physiology lead to differentials in their respective susceptibilities to chemical insult as evidenced by a variety of observations. As individuals undergo maturation from prenatal sex differentiation through pubertal development, these susceptibilities become evident in each gender. Gender bias occurs in human populations for birth defects and for the acceleration of the onset of puberty. Data on gender bias in fetal origins of adult disease are more complex. Useful for understanding reproductive and developmental effects in animals are a range of standard methodological procedures including the multigeneration testing protocol and the National Toxicology Program (NTP) Reproductive Assessment by Continuous Breeding (RACB). Examples of gender-based differences seen in reproductive toxicology studies on animals include teratogenic effects, reproductive effects in adult males and females, and effects on pubertal development. It is clear that gender biases exist in the reproductive and developmental toxicity, and the biological bases for these differences need to be explored.

Relationship between early puberty and the risk of hypertension/overweight at age 50: evidence for a modified Barker hypothesis among Polish youth

The objective of this paper is to evaluate: (a) the association between BMI in childhood and adolescence and BMI at age 50, and (b) the association between timing of maturation at puberty and BMI at age 50 and the occurrence of high blood pressure. We explore whether differences in somatic and physiological factors observed among children with early or late onset of puberty indicates that this period of life could be critical for appearance of some CVD risk factors later in the life cycle. Our data include 135 males and 148 females, born in 1953, participants in the Wrocław Longitudinal Study. Data pertaining to their growth and several indices of sexual and skeletal maturation were collected yearly between age 8 and 18. Subsequently, their anthropometric traits were measured and cardiovascular health status was assessed at age 50. We find that BMI at distinct stages in the life cycle were positively correlated. Also BMI at 50 were positively associated with blood pressure at 50. Moreover, earlier maturation at puberty is associated with higher values of BMI at age 50. We also find that earlier pubertal maturation is an independent factor that influences the appearance of high blood pressure in adulthood.

Do mothers understand healthy eating principles for low-birth-weight infants?

OBJECTIVES

To describe feeding patterns and mothers' perceptions of desirable feeding practices in low-birth-weight (LBW) infants after hospital discharge in England and to test for the association of inappropriate practices/perceptions with identifiable demographics.

DESIGN

Postal questionnaires from 198 mothers of LBW infants in London, Liverpool and Winchester were analysed regarding infant demographics, mothers' demographics, infant milks used, solid feeding practices and mothers' perceptions of infant feeding practices.

RESULTS

At birth, the median weight, independent of gestational age, was 1.80 kg (range 0.6-2.50 kg) and 37.1% of infants received breast milk exclusively; 83.7% were breast-fed at some stage, a practice favoured more by first-time mothers (90.2%) than multiparous mothers (73.4%) (P = 0.004) as well as by mothers of higher social groups (P = 0.019). The median age of solid food introduction was 17 postnatal weeks (range 8-36 weeks); the timing correlated strongly with infant birth weight (P < 0.001). A high-fibre diet and a low-fat diet were incorrectly considered important for their infants by 67.1% and 51.6% of mothers, respectively. Regarding a high-fibre diet as important was associated with being a multiparous mother (P = 0.006), while regarding a low-fat diet as important was associated with low social group (P = 0.018). A quarter of mothers did not consider 'plenty of calories' to be important for their infants, reflecting similar attitudes in 1990 for mothers of term infants; this incorrect attitude exhibited an association with being a first-time mother (P = 0.047).

CONCLUSIONS

Infant feeding practices were very variable, showing poor concordance with national and international recommendations for term infants. In selecting foods for their infants, many mothers appeared to be applying principles more appropriate to planning a healthy diet for adults. There is an urgent need to develop and implement evidence-based guidelines for feeding LBW infants after hospital discharge, with special attention given to multiparous mothers as well as mothers from lower social groups.

Body-composition assessment in infancy: air-displacement plethysmography compared with a reference 4-compartment model

BACKGROUND

A better understanding of the associations of early infant nutrition and growth with adult health requires accurate assessment of body composition in infancy.

OBJECTIVE

This study evaluated the performance of an infant-sized air-displacement plethysmograph (PEA POD Infant Body Composition System) for the measurement of body composition in infants.

DESIGN

Healthy infants (n = 49; age: 1.7-23.0 wk; weight: 2.7-7.1 kg) were examined with the PEA POD system. Reference values for percentage body fat (%BF) were obtained from a 4-compartment (4-C) body-composition model, which was based on measurements of total body water, bone mineral content, and total body potassium.

RESULTS

Mean (+/- SD) reproducibility of %BF values obtained with the PEA POD system was 0.4 +/- 1.3%. Mean %BF obtained with the PEA POD system (16.9 +/- 6.5%) did not differ significantly from that obtained with the 4-C model (16.3 +/- 7.2%), and the regression between %BF for the 4-C model and that for the PEA POD system (R2 = 0.73, SEE = 3.7%BF) did not deviate significantly from the line of identity (y = x).

CONCLUSIONS

The PEA POD system provided a reliable, accurate, and immediate assessment of %BF in infants. Because of its ease of use, good precision, minimum safety concerns, and bedside accessibility, the PEA POD system is highly suitable for monitoring changes in body composition during infant growth in both the research and clinical settings.

Effect of parental age and associated size on fecundity, growth and survival in the yellow seahorse Hippocampus kuda

Seahorses, together with the pipefishes (Family Syngnathidae), are the only vertebrates in which embryonic development takes place within a specialised body compartment, the brood pouch, of the male instead of the female. Embryos develop in close association with the brood pouch epithelium in a manner that bears some resemblance to embryo-placental relationships in mammals. We have explored the hypothesis that parental body size and age should affect offspring postnatal growth and survival if brood pouch quality impacts upon prenatal embryonic nutrition or respiration. Using an aquarium population of the yellow seahorse, Hippocampus kuda, we show here that large parents produce offspring whose initial postnatal growth rates (weeks one to three) were significantly higher than those of the offspring of younger and smaller parents. Whereas 90% of offspring from the larger parents survived for the duration of the study (7 weeks), less that 50% of offspring from smaller parents survived for the same period. For the offspring of large parents, growth rates from individual males were negatively correlated with the number of offspring in the cohort (r=-0.82; P<0.05); this was not the case for offspring from small parents (r=0.048; P>0.9). Observations of embryos within the pouch suggested that when relatively few embryos are present they may attach to functionally advantageous sites and thus gain physiological support during gestation. These results suggest that male body size, and pouch size and function, may influence the future fitness and survival of their offspring.

The Team Approach to Pregnancy and Congenital Heart Disease

The successful pediatric management of congenital heart disease has resulted in increasing numbers of these patients in the reproductive age group and increasing clinical challenges for their physicians. These challenges can be met successfully, with improved results for mother and child, through a concerted comprehensive team approach that relies on a thorough understanding of the patient's underlying cardiac pathology and its anticipated interaction with the pregnancy, and ongoing close evaluation and communication with a team of trained and experienced specialist, including (but not limited to) cardiologist, obstetricians, anesthetists, pediatricians, clinical nurse specialists, and clinical geneticists. Such teams are not always available locally and it will be necessary to refer medium- and high-risk patients to a specialized tertiary care center.

Early-life origins of the race gap in men's mortality

Using a life course framework, we examine the early life origins of the race gap in men's all-cause mortality. Using the National Longitudinal Survey of Older Men (1966-1990), we evaluate major social pathways by which early life conditions differentiate the mortality experiences of blacks and whites. Our findings indicate that early life socioeconomic conditions, particularly parental occupation and family structure, explain part of the race gap in mortality. Black men's higher rates of death are associated with lower socioeconomic standing in early life and living in homes lacking both biological parents. However these effects operate indirectly through adult socioeconomic achievement processes, as education, family income, wealth, and occupational complexity statistically account for the race gap in men's mortality. Our findings suggest that policy interventions to eliminate race disparities in mortality and health should address both childhood and adult socioeconomic conditions.

Early programming of body composition and fat distribution in adolescents

Size at birth and early postnatal growth are determinants of adult height and BMI. The aim of this study was to evaluate the effect of birth weight on body composition and fat distribution in a group of Spanish adolescents. Current body composition was assessed by both skinfold thickness and dual X-ray absorptiometry in 234 adolescents born at term (140 girls and 94 boys), now aged 13-18 y and living in the city of Zaragoza. Relative fat distribution was estimated using the ratio of the subscapular to triceps skinfolds (S:T). Birth weight and gestational age were assessed by a questionnaire. Birth weight was inversely associated with the S:T ratio (P < 0.05) in boys and directly associated with bone mass (P < 0.01) and fat-free mass (P < 0.05) in girls. This association was independent of factors such as age, Tanner stage, gestational age, socioeconomic status, physical activity, and height. In conclusion, our data support the hypothesis that impaired fetal growth, measured by birth weight, may be related to central fat distribution in boys and decreased bone and fat-free mass in girls.

Serum ghrelin concentration and weight gain in healthy term infants in the first year of life

OBJECTIVES

Ghrelin, a recently discovered hormone mainly secreted by the stomach, has several metabolic functions including regulation of food intake, energy homeostasis and body weight. There are few studies on this hormone in healthy infants during the first year of life. The aim of this study was to examine the correlations between ghrelin and weight gain in healthy term infants in the first year of life.

METHODS

104 healthy term infants aged 0 to 12 months were included in a cross-sectional study. Anthropometric measurements were assessed and mean weight gain was calculated. Serum ghrelin concentrations have been determined at least 3 hours after feeding by radioimmunoassay test.

RESULTS

Ghrelin concentrations were correlated negatively to weight gain (r=-0.302; P=0.003) and positively to age (r = 0.412; P < 0.001), weight (r = 0.374; P < 0.001) and length (r=0.387; P<0.001). In breastfed infants a statistically significant negative correlation between ghrelin concentration and infant weight gain (r=-0.407; P=0.001) was observed, whereas in formula-fed infants this correlation was not statistically significant (r=-0.067; P=0.719).

CONCLUSIONS

The negative correlation observed between ghrelin concentration and infant weight gain suggests that ghrelin might also play a role in the regulation of body weight in healthy infants with a physiologic energy balance. Further studies are needed to clarify how ghrelin might be involved in both short-term and long-term energy balance.

Blood pressure responses to feeding in infancy: spin-offs of serendipity

This article summarizes results from a program of research that has focused on understanding the characteristics of, and factors that shape, acute cardiovascular responses to feeding in infants. The work developed from behavioral observations in rats suggesting a linkage between variations in maternal behavior and adult blood pressure. However, the hypothesis that specific types of interactions, in particular those associated with feeding, might alter cardiovascular function was greatly influenced by a serendipitous observation made by Myron Hofer several years earlier. Myron discovered that nutrient availability is a key regulator of cardiovascular function in newborn rats. Our spin-off studies established that, in newborn rats and human infants, ingestion of nutrient is associated with robust increases in heart rate and blood pressure.

How much protein is safe?

BACKGROUND

Since breastfeeding and human milk seem to prevent, while high dietary proteins in the first 2 y of life seem to promote, later overweight, questions have been raised on the safe levels of proteins in the early years. How much protein (as a percentage of total calorie intake) is safe?

METHODS

Revision of available data on the protein content of human milk, protein intake in the first 2 y of life and their association with body mass development.

RESULTS

We should move from the figure of 7-8% in the 4-month exclusively breastfed infants up to the maximum acceptable levels of 14% in 12-24-month-old infants. When protein supply represents less than 6% and energy is limited, fully breastfed infants are likely to enter a status of negative nutrient balance. Over the limit of 14% energy from proteins in the 6-24 months period, some mechanisms may begin to operate, leading young children towards an early adiposity rebound and overweight development, beyond any genetic predisposition. Preliminary data seem to indicate a causal role for whole cow's milk proteins.

CONCLUSION

We suggest maintaining breastfeeding as long as possible, and, in case human milk is insufficient, to introduce infant formulas, appropriate for age, up to 18-24 months, in order to keep protein intakes in the safe range of 8-12% within a diet adequate in energy and balanced as far as macronutrients.

Early rapid weight gain and current overweight in relation to asthma in adolescents born with very low birth weight

Early catch-up growth and subsequent overweight are suggested to be associated with later cardiovascular diseases and later type II diabetes. However, the impact of early catch-up growth and childhood overweight on the development of asthma has been less studied, particularly in children born with very low birth weight (VLBW). A birth cohort of 74 VLBW children (birth weight < or = 1500 g) was followed from birth and investigated on asthma at 12 yr of age. Early rapid weight gain was in one way defined as an increase of weight > or =1 standard deviation score (SDS) at 6 months of corrected postnatal age. Current overweight was defined by body mass index (BMI) exceeding 21.2 and 21.7 kg/m(2), respectively, for boys and girls at 12 yr of age. Current asthma was diagnosed by a pediatrician, according to asthma ever in combination with a positive response to hypertonic saline bronchial provocation test and/or wheeze at physical examination at 12 yr old. Being overweight at 12 yr of age was associated with an increased risk for current asthma in the VLBW children [crude odds ratio (OR): 5.5, 95% confidence interval (CI): 1.3-22.2]. After adjustment for early weight gain and neonatal risk, the OR of overweight increased nearly three times (adjusted OR: 15.3, 95% CI: 2.5-90.6). Early rapid weight gain seemed to be inversely associated with current asthma (adjusted OR: 0.49 for an increase of weight equal to 1 SDS, 95% CI: 0.23-1.02, p = 0.06). In addition, early rapid weight gain was inversely associated with the magnitude of bronchial responsiveness at 12 yr (coefficient -1.15, p < 0.01). There was a strong and positive association between overweight and asthma at 12 yr of age in the VLBW children. This strong association had been reduced by early rapid weight gain, possibly via the reduction of bronchial responsiveness.

A review of low birth weight: predictors, precursors and morbidity outcomes

This paper reviews the global evidence concerning infant low birth weight (LBW) (2.500kg and below) in relation to suggested causative factors, such as undernutrition, stress, smoking, drug abuse and deprived living environments. In addition, health promotion strategies in place to reduce LBW incidence in both developed and underdeveloped countries are reviewed. The paper also focuses on the high incidence of LBW in the UK in comparison to other European and developed countries. Predictors of LBW are then considered comparing findings of a study conducted in the UK with findings in underdeveloped countries. In addition, LBW risk is discussed in the context of vulnerability factors, such as teen pregnancy, child abuse and domestic violence. In conclusion, the author argues for a health promotion policy in the UK to reduce incidence of LBW in areas of deprivation and suggests that the improvement of maternal health is key in improving the health of today's infants and children who will one day become the adults of tomorrow.

The relation between birth weight and intima-media thickness in middle-aged adults

BACKGROUND

Birth weight has been found to be inversely associated with the risk of coronary heart disease and stroke, although the mechanisms for this association remain unclear. Here, we investigate the relation between reported birth weight and atherosclerosis in middle age.

METHODS

We included the 9817 participants (age 44-65) in the Atherosclerosis Risk in Communities (ARIC) study who were neither a twin nor born prematurely. Carotid atherosclerosis was assessed as intima-media thickness measured by B-mode ultrasound. We studied the association with recalled exact birth weight, and for those unable to recall exact birth weight, with recalled birth weight category.

RESULTS

Mean intima-media thickness (+/- standard deviation) was 0.73 +/- 0.17 mm. Mean birth weight for the 4635 participants recalling exact birth weight was 3.49 +/- 0.71 kg. A further 4946 participants recalled birth weight category, with 4730 (96%) reporting "medium" birth weight. In univariate analysis, birth weight and intima-media thickness were positively related. However, adjustment for confounding factors reduced the association to only a 0.004 mm higher intima-media thickness (95% CI = - 0.003 to 0.011) mm per 1 kg of birth weight. The same pattern of univariate positive relationship and attenuation with adjustment was seen for birth weight category and intima-media thickness. There was no evidence of interaction between adult body mass index (BMI) and birth weight, or of interaction between category of adult BMI and birth weight category. An inverse relation between birth weight category and intima-media thickness was seen only for those in the lowest category of adult BMI (BMI <25 kg/m).

CONCLUSIONS

We found no evidence of a clinically significant relation between birth weight and carotid atherosclerosis.

Birth weight predicts response to vaccination in adults born in an urban slum in Lahore, Pakistan

BACKGROUND

Substantial evidence exists linking small size at birth to later-life susceptibility to chronic disease. Evidence is also emerging that some components of immune function may be programmed in early life. However, this evidence is limited and requires confirmation.

OBJECTIVE

We investigated the association between size at birth and response to vaccination in a cohort of 257 adults (mean age: 29.4 y; 146 men) born in an urban slum in Lahore, Pakistan, during 1964-1978.

DESIGN

A single dose of Vi polysaccharide vaccine for Salmonella typhi and 2 doses of rabies vaccine were given to each subject. Antibody titers were measured in prevaccination serum samples (Vi) and in postvaccination samples (Vi and rabies).

RESULTS

The mean birth weight of the subjects was 3.24 kg; 14% of the subjects had low birth weights (<2.5 kg). Vaccine responses were not consistently associated with contemporary variables (month of study, sex, current age, or indicators of wealth). Response to typhoid vaccination was positively related to birth weight (anti-Vi immunoglobulin G: r = 0.138, P = 0.031; anti-Vi immunoglobulin M: r = 0.197, P = 0.034). Response to the rabies vaccine was not significantly associated with birth weight.

CONCLUSIONS

These findings add to a growing body of evidence suggesting that components of the immune system may be permanently programmed by events in early life. The contrasting effects on typhoid and rabies responses suggest that antibody generation to polysaccharide antigens, which have greater B cell involvement, is compromised by fetal growth retardation.

Associations of components of adult height with coronary heart disease in postmenopausal women: the British women's heart and health study

OBJECTIVE

To assess the associations between components of adult height and coronary heart disease (CHD) in postmenopausal women.

METHODS

Cross sectional analysis of 4286 women randomly selected from 23 British towns. The association of components of adult height with prevalent CHD (n = 694) were assessed.

RESULTS

Shorter stature, shorter leg length, and trunk length were all associated with CHD in age adjusted analyses. The association between trunk length and CHD was attenuated to the null with adjustment for smoking. The leg length-CHD association was independent of smoking, socioeconomic position in childhood and adulthood, birth weight, and other potential confounders. Insulin resistance did not appear to be an important mediating factor in the association between leg length and CHD. After full adjustment for all potential confounding factors the odds ratio (95% confidence interval) of CHD for a 1 SD (4.3 cm) increase in leg length was 0.84 (0.77 to 0.93) and the odds ratio for a 1 SD (0.05) increase in the leg to trunk ratio was 0.85 (0.79 to 0.95).

CONCLUSIONS

The specific association between leg length and CHD suggests that early life environmental exposures that influence skeletal growth also influence CHD risk in later life.

Differential association of birth weight with cardiovascular risk variables in African-Americans and Whites: the Bogalusa heart study

PURPOSE

To study the relationship between low birth weight and the subsequent development of cardiovascular risk factors and to compare this relationship between African-Americans and whites at 7 to 21 years of age.

METHODS

The relationship of birth weight with cardiovascular risk factors, namely, systolic and diastolic blood pressure (BP), BMI, HDL, LDL, triglycerides, and HOMA insulin resistance (HOMA-IR) was examined retrospectively using information on 1155 participants (730 whites and 425 African-Americans) from two cohorts of the Bogalusa Heart Study.

RESULTS

Participants with lower birth weight had higher systolic BP, HOMA-IR, triglycerides, and LDL. The association of birth weight with LDL, triglycerides, and HOMA-IR was stronger in African-Americans, while the association with systolic BP was stronger in whites. Subjects with birth weight <2500 g were at increased risk of having values of HOMA-IR and LDL in the upper quartile of the observed range compared with those with birth weight >2500 g.

CONCLUSIONS

These results support a relationship between low birth weight and the later development of important cardiovascular risk factors in young African-Americans and white individuals. This relationship tends to be stronger in African-Americans than in whites, except for systolic blood pressure.

The Aberdeen Children of the 1950s cohort study: background, methods and follow-up information on a new resource for the study of life course and intergenerational influences on health

In this paper we introduce and describe in detail an addition to the UK's population-based resources for the investigation of biological and social influences on health across the life course and between generations: the Aberdeen Children of the 1950s study. We also provide an account of postwar Aberdeen when study members were growing up, report on findings of analyses of data from the original survey on which this study is based and its follow-up, assess the strengths and limitations of the study, and outline current and future research directions. This cohort comprises individuals born in Aberdeen, Scotland (UK) between 1950 and 1956, and is derived from 15 thousand subjects who took part in the Aberdeen Child Development Survey, a cross-sectional study of 'mental subnormality' (learning disability) in a population of all children who were attending Aberdeen primary schools in December 1962. Data collection included information on birthweight, gestational age, childhood height and weight, tests of cognition and behavioural disorder, and a range of multilevel socio-economic indicators. In 1998 we began the process of revitalising this cohort (now termed the Aberdeen Children of the 1950s study). We have been successful in ascertaining the current vital status and whereabouts of 98.5% of a target population of 12 150 subjects (6276 males, 5874 females) with full baseline data. The large majority (81%) of study participants still reside in Scotland and many (73%) have remained in the Grampian region which incorporates Aberdeen. At the present time, a total of almost 500 subjects are known to have died. Linkages to hospital admissions and other health endpoints captured through the Scottish Morbidity Records system have been completed. This includes an intergenerational linkage to approximately eight thousand deliveries in Scotland occurring to female members of the study population. A postal questionnaire to all traced surviving cohort members has also been distributed.

Insulin resistance in healthy prepubertal twins

OBJECTIVES

To evaluate insulin sensitivity (S(I)) in prepubertal twins and to examine the relation to reduced birth weight, prematurity, and peroxisome proliferator-activated receptor-gamma (PPAR gamma) polymorphism.

STUDY DESIGN

Fifty twins (birth weight SDS, -0.7 +/- 0.2; gestation, 33.5 +/- 0.5 weeks; and body mass index SDS, -0.04 +/- 0.2) were studied at 8.2 +/- 0.3 years. S(I) was measured by Bergman's minimal model from a 90 minutes frequently sampled intravenous glucose test. Twenty control children (height SDS, -1.7 +/- 0.3; birth weight SDS, -0.3 +/- 0.2; and gestation of 39.2 +/- 0.7 weeks) were also evaluated at 7.0 +/- 0.4 years. The PPAR gamma T-variant polymorphism was evaluated in 41 twins. Values are expressed as mean +/- SEM, or 95% confidence intervals.

RESULTS

S(I) was reduced in twins compared with control subjects, (12.7 [11-15] versus 23.0 [16.8-31.4] 10(-4) min(-1) microU/mL, respectively, P=.005). The reduction in S(I) was independent of prematurity and birth weight and zygosity (P<.0001). There was no difference in S(I), even in twin pairs with >20% difference in birth weight (P=.9). The PPAR gamma heterozygote T-variant polymorphism was present in 7 of 41, with a further reduction in S(I) (P=.03) and a later gestation (P=.03). These twins also had increased fat mass (P=.02) but with similar fat free mass (P=.14).

CONCLUSIONS

Twin children, independent of prematurity or birth weight, had a marked reduction in S(I). To use twins as a model to study the fetal origins of adult diseases for glucose homeostasis is not valid.

Studies on human body composition during the first 4 months of life using magnetic resonance imaging and isotope dilution

Assessing body composition during infancy requires data for the so-called reference infant. Currently available data for this purpose need to be updated and extended using methods based on principles different from those used previously to define the reference infant. Thus, magnetic resonance imaging was applied to full-term healthy boys (n = 25) and girls (n = 21), 4-131 d old, to estimate adipose tissue volume (ATV) and the amounts of s.c. and non-s.c. adipose tissue (AT). Total body water was estimated using isotope dilution. Total body fat (TBF), fat free weight (FFW) and the degree of hydration in FFW were calculated. Increases in weight, TBF, and FFW with age agreed with current reference data, although when compared with the reference, a slightly more rapid increase in % TBF was observed for boys. The degree of hydration in FFW was 78.9 +/- 4.5% (n = 45). Both sexes showed significant increases with age in s.c. ATV (14.7 and 13.0 mL/d for boys and girls, respectively) and in non-s.c. ATV (1.58 and 1.26 mL/d, respectively). Subcutaneous ATV was 90.5 +/- 1.8% (boys) and 91.1 +/- 1.9% (girls) of total ATV. In conclusion, a pronounced increase with age in the amount of AT was demonstrated involving a considerable gain in s.c. fat during early life. Except for % TBF in boys, changes in body composition with age agreed with current reference data.

Approaches to detecting growth faltering in infancy and childhood

One of the purposes of monitoring a child's weight or height is to detect growth faltering. In infancy the focus is on monitoring weight gain, primarily for detecting infants at risk of failure-to-thrive. In childhood, this switches to height gain, e.g. the response of a child that is growth hormone deficient to treatment with growth hormone. Cross-sectional charts provide no guidance in a longitudinal context. If we note the current weight or height of a child, but want to say something about a child's growth since the last weight and height measurement, we need to use a velocity/increment reference or take a conditional approach to the problem. Here we focus on growth faltering and review the mathematical approaches to this problem. Discussion will concentrate on the relative merits of the following approaches: velocity references and increment charts or tables; conditional gain Z-scores;infancy weight-monitoring charts and longitudinal growth norms implemented in the growth package LGROW; tracking indices and distance charts and centile crossing. Overall conditional gain Z-scores provide the most flexible means of assessing growth patterns.

Increased nocturnal blood pressure in healthy prepubertal twins

AIM

To compare ambulatory blood pressure monitoring (ABPM) in twin children to a published singleton population, and to examine the influence of birthweight and fasting plasma cortisol on blood pressure.

DESIGN

A cross-sectional study of monozygotic and dizygotic twins compared with a similar previously published normative control population.

METHODS

Forty-four healthy prepubertal twin children aged 4-11 years (20 monozygotic, 22 male) were studied. All subjects had 24-h ABPM and a fasting early morning plasma cortisol.

RESULTS

Twins had higher 24-h systolic blood pressure (BP) compared with controls with similar daytime and elevated night-time systolic BP (P > 0.3 and P < 0.01, respectively). Twins had reduced systolic and diastolic nocturnal BP dipping compared with controls (P < 0.0001 for both), and 61% of twins exhibited a < 10% fall in nocturnal BP. In the twin cohort there was no association between birth weight and daytime systolic BP (P = 0.6), nor any other ABPM parameter. There was no difference in BP parameters between dizygotic and monozygotic twins, and no difference between the lighter and heavier birthweight twins for any ABPM parameter. Fasting plasma cortisol was not associated with either birthweight (P = 0.2) or daytime systolic BP (P = 0.4).

CONCLUSIONS

Healthy prepubertal twins have increased nocturnal BP and reduced nocturnal BP dipping independent of zygosity or birthweight. These abnormalities may be a risk factor for the later development of hypertension in twins. As these BP abnormalities are not associated with twin birth weight, the twin model may not be appropriate in investigating the fetal origins of disease in later adult life.

Contents of chemical elements in stomach during prenatal development: different age-dependent dynamical changes and their significance

AIM: To observe dynamic of different chemical elements in stomach tissue during fetal development.

METHODS: To determine contents of the 21 chemical elements in each stomach samples from fetus aging four to ten months. The content values were compared to those from adult tissue samples, and the values for each month group were also analyzed for dynamic changes.

RESULTS: Three representations were found regarding the relationship between contents of the elements and ages of the fetus, including the positive correlative (K), reversely correlative (Na, Ca, P, Al, Cu, Zn, Fe, Mn, Cr, Sr, Li, Cd, Ba, Se) and irrelevant groups (Mg, Co, Ni, V, Pb, Ti).

CONCLUSION: The chemical elements’ contents in stomach tissues were found to change dynamically with the stomach weights. The age-dependent representations for different chemical elements during the prenatal development may be of some significance for assessing development of fetal stomach and some chemical elements. The data may be helpful for the nutritional balance of fetus and mothers during prenatal development and even the perinatal stages.

Increased blood pressure in adolescents of low socioeconomic status with short stature

The nutritional programming hypothesis, which has been studied since the 1970s, proposes that intrauterine undernutrition continuing during the first years of life causes permanent metabolic disorders. These alterations are amplified with time, depending on the quality of the diet and on environmental factors. The aim of this cross-sectional study was to detect blood pressure alterations in teenagers with nutritional deficit. The study sample consisted of 53 adolescents living in shantytowns of São Paulo City, Brazil; 27 boys and 26 girls ranging in age from 11 to 16 years were studied. Weight, height, skinfold thickness, and blood pressure were measured during a medical visit. Anthropometric data were compared with the reference values of the National Center for Health Statistics and Frisancho, and arterial pressure data were compared with the reference values of the 1996 Task Force. The adolescents studied are among the 10% poorest stratum of the Brazilian population, with a per capita income of U.S. $45/month. The anthropometric results revealed nutritional deficiencies for the entire sample. The major marker of malnutrition was height, with a mean height deficit of 7 cm among boys and of 5 cm among girls. The overall prevalence of arterial (diastolic) hypertension for the sample was 21% (95% confidence interval 10%-32%). No significant difference was observed between sexes. The prevalence of cases with a systolic or diastolic arterial pressure above the 90th percentile, adjusted for height, was 51% ( n=27) (95% confidence interval 37%-65%); 6% ( n=3) of these individuals had simultaneous systolic and diastolic arterial hypertension. In conclusion, the prevalence of arterial hypertension was elevated among malnourished adolescents. The mechanisms involved in the genesis of hypertension seem to be related to malnutrition during an early phase of life, supporting the programming hypothesis.

Early and late growth and blood pressure in adolescence

OBJECTIVE

To assess the effect of growth during infancy and childhood on blood pressure in adolescence.

DESIGN

Birth cohort study.

SETTING

Pelotas, southern Brazil.

PARTICIPANTS

749 adolescents with complete information on birth weight and gestational age, as well as on anthropometric data at all three follow up visits (mean age 20 months, 42 months, and 15 years).

MAIN OUTCOME MEASUREMENTS

Systolic and diastolic blood pressure at adolescence.

RESULTS

After controlling for possible confounding variables, birth weight was negatively associated with systolic blood pressure, one unit increase in standard deviation score of birth weight for gestational age was associated with a decrease of 1.23 mm Hg (95% confidence intervals -2.03 to -0.43) in systolic blood pressure. Weight for age z score at the age of 15 years showed a strong positive association with systolic blood pressure, one unit increase in standard deviation score of birth weight for gestational age was associated with an increase of 4.4 mm Hg (95% confidence intervals 3.50 to 5.3). Diastolic blood pressure was not associated with birth weight. For adequate for gestational age infants, the positive association between weight in adolescence and blood pressure became stronger when previous weights were added to the model.

CONCLUSION

This study showed that early--as well as--late catch up growth is associated with increased systolic blood pressure in adolescence, whereas only late catch up is related with diastolic blood pressure. These findings suggest that catch up growth, irrespective of age, is associated with increased blood pressure in adolescence.

Ovulation induction/intrauterine insemination in infertile couples is associated with low-birth-weight infants

OBJECTIVE

The study was undertaken to determine the outcome of singleton pregnancies conceived through ovulation induction and intrauterine insemination using a partner's (OI/IUI) or donor sperm (OI/IUID) by comparison with naturally conceived singletons within a national cohort.

STUDY DESIGN

Retrospective cohort study in primigravid women who were treated with OI/IUI (n = 97) or OI/IUID (n = 35) at Glasgow Royal Infirmary between March 1993 and March 1997 and identified within the Scottish national cohort (n = 109,443) delivering during the same period. Univariate and multivariate logistic regression models were used to examine outcomes and to determine the factors associated with infertility treatment and low birth weight.

RESULTS

OI/IUI singletons were more likely to be lighter, of clinically low birth weight, and born more prematurely than natural conceptions. After adjustment for associated factors, these infants were 4.85 times (95% CI 2.25-10.48) more likely to be of low birth weight. We could not demonstrate any differences between OI/IUID and natural conceptions.

CONCLUSION

The perinatal outcome of singletons born to subfertile mothers conceived through OI/IUI is poorer than that of matched natural conceptions. We suggest that intrinsic factors in subfertile couples predispose them to having smaller infants and that "infertility" should be added to the list of recognized factors associated with low birth weight.