Obesity and adiposity of 3- to 6-year-old children born to mothers with hyperglycaemia first detected in pregnancy in an urban South African setting.

BACKGROUND: Understanding the association between maternal metabolic conditions in pregnancy and the risk of childhood overweight, a growing concern in sub-Saharan Africa (SSA), helps to identify opportunities for childhood obesity prevention. AIM: To assess the association between hyperglycaemia first detected in pregnancy (HFDP) (gestational diabetes mellitus [GDM] and diabetes in pregnancy [DIP]) and child obesity and adiposity in pre-school-aged children in South Africa, independently of maternal BMI. SUBJECTS AND METHODS: Measurement of anthropometry and fat mass index (FMI) by the deuterium dilution method was done for 102 3-6-year-old children born to mothers with HFDP and 102 HFDP-unexposed children. Hierarchical regression analysis and generalised structural equation modelling (GSEM) were performed. RESULTS: The prevalence of overweight/obesity was 10.5% and 11.1% in children exposed to GDM and DIP, respectively, and 3.9% in the HFDP-unexposed group. Log-transformed FMI was significantly higher in the DIP-exposed group (ß = 0.166, 95% CI = 0.014-0.217 p= .026), but not when adjusting for maternal pregnancy BMI (ß = 0.226, 95% CI = 0.003-0.015, p = .004). GSEM showed significant total effects of maternal BMI and birth weight on FMI/BMI. CONCLUSIONS: Maternal pregnancy BMI seems to play a greater role in the development of childhood adiposity than maternal hyperglycaemia, requiring further research and identifying maternal BMI as a relevant prevention target in our setting.

Model Development for Fat Mass Assessment Using Near-Infrared Reflectance in South African Infants and Young Children Aged 3-24 Months.

Undernutrition in infants and young children is a major problem leading to millions of deaths every year. The objective of this study was to provide a new model for body composition assessment using near-infrared reflectance (NIR) to help correctly identify low body fat in infants and young children. Eligibility included infants and young children from 3-24 months of age. Fat mass values were collected from dual-energy x-ray absorptiometry (DXA), deuterium dilution (DD) and skin fold thickness (SFT) measurements, which were then compared to NIR predicted values. Anthropometric measures were also obtained. We developed a model using NIR to predict fat mass and validated it against a multi compartment model. One hundred and sixty-four infants and young children were included. The evaluation of the NIR model against the multi compartment reference method achieved an r value of 0.885, 0.904, and 0.818 for age groups 3-24 months (all subjects), 0-6 months, and 7-24 months, respectively. Compared with conventional methods such as SFT, body mass index and anthropometry, performance was best with NIR. NIR offers an affordable and portable way to measure fat mass in South African infants for growth monitoring in low-middle income settings.

Assessing Breastfeeding Practices Objectively Using Stable Isotope Techniques.

An objective method of assessing breastfeeding practices is required to evaluate progress toward the World Health Organization Global Target 2025: to increase exclusive breastfeeding (EBF) rates in the first 6 months to at least 50% by 2025. Currently, assessment of EBF at the population level is based on mother or caregiver reporting, which risks recall and social desirability bias. A more objective method is the deuterium oxide dose to mother (DTM) technique, in which lactating mothers are given a small amount of deuterium-labeled water. The infant receives deuterium during breastfeeding, and a compartmental model is used to determine the amount of human milk consumed by the infant, and the exclusivity of breastfeeding practices. If the amount of human milk consumed by an infant is determined using the DTM technique and the concentration of nutritional components or potentially toxic contaminants is measured, then the infant's intake of essential nutrients or environmental contaminants can be ascertained.

Development of a nonlinear hierarchical model to describe the disposition of deuterium in mother-infant pairs to assess exclusive breastfeeding practice.

The World Health Organization recommends exclusive breastfeeding (EBF) for the first 6 months after birth. The deuterium oxide dose-to-the-mother (DTM) technique is used to distinguish EBF based on a cut-off (< 25 g/day) of water intake from sources other than breastmilk. This value is based on a theoretical threshold and has not been verified in field studies. The aim of this study was to estimate the water intake cut-off value that can be used to define EBF practice. One hundred and twenty-one healthy infants, aged 2.5-5.5 months who were deemed to be EBF were recruited. After administration of deuterium to the mothers, saliva was sampled from mother and infant pairs over a 14-day period. Validation of infant feeding practices was conducted via home observation over six non-consecutive days with caregiver recall. A fully Bayesian framework using a gradient-based Markov chain Monte Carlo approach implemented in Stan was used to estimate the cut-off of non-milk water intake of EBF infants. From the original data set, 113 infants were determined to be EBF and provided 1500 paired mother-infant observations. The deuterium saliva concentrations were best described by two linked 1-compartment models (mother and infant), with body weight as a covariate on the mother's volume of distribution and infant's body weight on infant's water clearance rate. The cut-off value was based on the 90th percentile of the posterior distribution of non-milk water intake and was 86.6 g/day. This cut-off value can be used in future field studies in other geographic regions to determine exclusivity of breast feeding practices in order to determine their potential public health needs.

Nutritional status and human milk intake of exclusively breast-fed infants at high altitude in La Paz, Bolivia.

Breast-feeding habits are related to the nutritional status and the risk of illness and death in children under 2 years of age. For the first 6 months, infants should be exclusively breast-fed. This study aimed to evaluate the relationship between the infant's nutritional status and human milk intake by breast-fed infants at high altitude. A quantitative, descriptive, correlational study was conducted including mother/baby pairs of infants aged 2-6 months. The amount of human milk consumed by the infants was assessed by the deuterium oxide dose-to-mother technique. The lipid content of human milk was measured by creamatocrit, and anthropometric measurements were performed. A total of eighteen mother/baby pairs were assessed. The mean human milk intake was 888 (sd 149) g/d, and the intake of water from other sources was 24·3 (sd 29·8) g/d. The lipid content in human milk was 41 (sd 12) g/l. The infant's nutritional indicators were normal in all cases. A moderate positive correlation was found between milk volume and z scores weight-for-length r 0·58 (P=0·01), BMI-for-age r 0·56 (P=0·01) and weight-for-age r 0·45 (P=0·05). There was no correlation with length-for-age z score. The mean of breast milk intake in this study was similar to that found in other studies in the world. The lipid content is comparable to similar studies and was within the normal range. Children older than 3 months showed signs of stunting despite adequate volume and lipid content of breast milk.

Availability of arsenic in human milk in women and its correlation with arsenic in urine of breastfed children living in arsenic contaminated areas in Bangladesh.

BACKGROUND: Early life exposure to inorganic arsenic may be related to adverse health effects in later life. However, there are few data on postnatal arsenic exposure via human milk. In this study, we aimed to determine arsenic levels in human milk and the correlation between arsenic in human milk and arsenic in mothers and infants urine. METHODS: Between March 2011 and March 2012, this prospective study identified a total of 120 new mother-baby pairs from Kashiani (subdistrict), Bangladesh. Of these, 30 mothers were randomly selected for human milk samples at 1, 6 and 9 months post-natally; the same mother baby pairs were selected for urine sampling at 1 and 6 months. Twelve urine samples from these 30 mother baby pairs were randomly selected for arsenic speciation. RESULTS: Arsenic concentration in human milk was low and non-normally distributed. The median arsenic concentration in human milk at all three time points remained at 0.5 µg/L. In the mixed model estimates, arsenic concentration in human milk was non-significantly reduced by -0.035 µg/L (95% CI: -0.09 to 0.02) between 1 and 6 months and between 6 and 9 months. With the progression of time, arsenic concentration in infant's urine increased non-significantly by 0.13 µg/L (95% CI: -1.27 to 1.53). Arsenic in human milk at 1 and 6 months was not correlated with arsenic in the infant's urine at the same time points (r = -0.13 at 1 month and r = -0.09 at 6 month). Arsenite (AsIII), arsenate (AsV), monomethyl arsonic acid (MMA), dimethyl arsinic acid (DMA) and arsenobetaine (AsB) were the constituents of total urinary arsenic; DMA was the predominant arsenic metabolite in infant urine. CONCLUSIONS: We observed a low arsenic concentration in human milk. The concentration was lower than the World Health Organization's maximum permissible limit (WHO Permissible Limit 15 µg/kg-bw/week). Our findings support the safety of breastfeeding even in arsenic contaminated areas.

Discordance in exclusive breastfeeding between maternal recall and deuterium dose-to-mother technique during the first 6 months of infants: A multi-country study in Asia.

PURPOSE: This study aimed to assess the agreement in EBF between maternal recall and the dose-to-mother (DTM) technique. METHODS: Indonesia, Malaysia, Mongolia, Pakistan, Sri Lanka, Thailand, and Vietnam participated in the study. A total of 207 and 118 mother-infant pairs were assessed at 3 and 6 months of child's age. Using a standardized questionnaire, mothers were asked to recall child feeding during the previous 24 h, at 3 and 6 months. Those recalled to be EBF proceeded to be assessed using DTM technique. Non-milk oral intake (NMOI) cutoff of 86.6 g/d was used to classify EBF. RESULTS: According to DTM, 66% of infants were EBF at 3 months, while only 22% were EBF at 6 months. At 3 months, the overall % agreement between maternal recall and DTM method was 68%, kappa 0.06 (95% CI: 0.07-0.20), and at 6 months, the % agreement was only 21%, kappa -0.031 (95% CI -0.168 to 0.107). Human milk intakes were similar at 3 months and 6 months when expressed as g/d, but decreased when expressed as g/kg/d, with a large variation within and between countries; Pakistan being the lowest. CONCLUSION: This study showed there were declining levels of EBF from 3 to 6 months in the participating countries from Asia and the agreement between maternal recall and DTM technique to classify EBF was low. To ensure that the DTM technique can be more widely used in evaluating breastfeeding promotion programs, consensus on the appropriate NMOI cutoff and simplification of the DTM protocol is necessary.

Infant body composition at 6 and 24 months: what are the driving factors?

BACKGROUND/OBJECTIVE: Available evidence on infant body composition is limited. This study aimed to investigate factors associated with body composition at 6 and 24 months. SUBJECTS/METHODS: Multicenter study with data from a 0 to 6-mo cohort (Australia, India and South Africa) and a 3 to 24-mo cohort (Brazil, Pakistan, South Africa, and Sri Lanka). For the 0-6-mo cohort, body composition was assessed by air-displacement plethysmography (ADP) and for the 3-24-month cohort by the deuterium dilution (DD) technique. Fat mass (FM), fat-free mass (FFM), FM index (FMI), and FFM index (FFMI) were calculated. Independent variables comprised the Gini index of the country, maternal and infant characteristics, and breastfeeding pattern at 3 months. For the 3-24-mo cohort, breastfeeding, and minimum dietary diversity (MDD) at 12 months were also included. Crude and adjusted analyses stratified by sex were conducted by multilevel modelling using mixed models. RESULTS: At 6 months, every 1 kg increase in birth weight was associated with an increase of 0.716 kg in FFM and 0.582 kg/m2 in FFMI in girls, whereas in boys, the increase was of 0.277 kg in FFM. At 24 months, compared to those weaned before 12 months, girls still breastfed at 12 months presented a decrease of 0.225 kg in FM, 0.645 kg in FFM and 0.459 kg/m2 in FFMI, and in boys the decreases were of 0.467 kg in FM, 0.603 kg in FFM and 0.628 kg/m2 in FFMI. CONCLUSION: Birth weight and breastfeeding are independent predictors of body composition in early life, irrespective of sex.

Body composition from birth to 2 years.

Providing all infants with the best start to life is a universal but challenging goal for the global community. Historically, the size and shape of infants, quantified by anthropometry and commencing with birthweight, has been the common yardstick for physical growth and development. Anthropometry has long been considered a proxy for nutritional status during infancy when, under ideal circumstances, changes in size and shape are most rapid. Developed from data collected in the Multicentre Growth Reference Study (MGRS), WHO Child Growth Standards for healthy infants and children have been widely accepted and progressively adopted. In contrast, and somewhat surprisingly, much less is understood about the 'quality' of growth as reflected by body composition during infancy. Recent advances in body composition assessment, including the more widespread use of air displacement plethysmography (ADP) across the first months of life, have contributed to a progressive increase in our knowledge and understanding of growth and development. Along with stable isotope approaches, most commonly the deuterium dilution (DD) technique, the criterion measure of total body water (TBW), our ability to quantify lean and fat tissue using a two-compartment model, has been greatly enhanced. However, until now, global reference charts for the body composition of healthy infants have been lacking. This paper details some of the historical challenges associated with the assessment of body composition across the first two years of life, and references the logical next steps in growth assessments, including reference charts.

Body composition reference charts for infants from birth to 24 months: Multicenter Infant Body Composition Reference Study.

BACKGROUND: Body composition assessment in the first 2 y of life provides important insights into child nutrition and health. The application and interpretation of body composition data in infants and young children have been challenged by a lack of global reference data. OBJECTIVES: We aimed to develop body composition reference charts of infants aged 0-6 mo based on air displacement plethysmography (ADP) and those aged 3-24 mo based on total body water (TBW) by deuterium dilution (DD). METHODS: Body composition was assessed by ADP in infants aged 0-6 mo from Australia, India, and South Africa. TBW using DD was assessed for infants aged 3-24 mo from Brazil, Pakistan, South Africa, and Sri Lanka. Reference charts and centiles were constructed for body composition using the lambda-mu-sigma method. RESULTS: Sex-specific reference charts were produced for FM index (FMI), FFM index (FFMI), and percent FM (%FM) for infants aged 0-6 mo (n = 470 infants; 1899 observations) and 3-24 mo (n = 1026 infants; 3690 observations). When compared with other available references, there were observable differences but similar patterns in the trajectories of FMI, FFMI, and %FM. CONCLUSIONS: These reference charts will strengthen the interpretation and understanding of body composition in infants across the first 24 mo of life.

Development of a Parsimonious Design for Optimal Classification of Exclusive Breastfeeding.

A deuterium oxide dose-to-mother (DTM) technique is used to determine if an infant is exclusive breastfeeding (EBF). However, the DTM method is intensive, requiring seven paired mother-infant samples during a 14-day study period. The purpose of this study was to develop a field-friendly protocol. Data from 790 mother-infant pairs from nine countries were analyzed using a Markov chain Monte Carlo method with Stan. The data were split into (i) model building (565 pairs) and (ii) design evaluation (225 pairs). EBF classification was based on a previously published cut-off for nonmilk water intake. Classification based on the full design was the reference (gold standard classification). The receiver operating characteristics of parsimonious designs were used to determine an optimal parsimonious classification method. The best two postdose windows (days 7-9 and 13-14) yielded optimal categorization with similar performance in the design evaluation data. This postdose two-sample design provided 95% sensitivity and specificity when compared with the full design.

Benefits of salmon eating on traditional and novel vascular risk factors in young, non-obese healthy subjects.

AIM: The present clinical study tested the hypothesis that oil-rich fish consumption improves CHD risk factors. METHODS: Forty-eight (16 men) non-obese, healthy adults aged 20-55, consumed 125 g/day of salmon for a 4-week period followed by a 4-week period with no-fish (41 completers). Subjects were instructed to maintain dietary and physical activity patterns during the period of study. Blood pressure, anthropometric, body composition and dietary information with fasting blood samples to determine traditional and novel CHD risk markers and plasma fatty acids were obtained before and after each period. RESULTS: Compared to no-fish, eating salmon significantly decreased systolic, diastolic and mean arterial blood pressure by 4%, triglycerides by 15%, and LDL-cholesterol by 7%, and significantly increased HDL-cholesterol by 5% (P<0.05). The changes in blood pressure and lipids alone with salmon intake predict around a 25% reduction in CHD risk based on the PROCAM risk calculator. Plasma adiponectin demonstrated a trend towards improvement (8.39 micromol/L with salmon and 7.52 with no-fish; P=0.086) but no significant changes were found either in plasma leptin, glucose or insulin after salmon consumption. CONCLUSIONS: Daily consumption of salmon improves traditional risk predictors of CHD in non-obese subjects. Adiponectin may be involved but the impact on novel risk factors needs study in high-risk subjects.

Using stable isotope techniques in nutrition assessments and tracking of global targets post-2015.

Stable isotopes are non-radioactive, safe and are applied for various purposes in human health assessment in trace amounts that minimally disturb normal physiology. The International Atomic Energy Agency supports the use of stable isotope techniques to design and evaluate interventions addressing malnutrition in all its forms with focus on infant and young child feeding; maternal and adolescent nutrition; diet quality; prevention and control of non-communicable diseases; healthy ageing and gut function. These techniques can be used to objectively measure: (1) amount of human milk consumed and whether an infant is exclusively breastfed; (2) body composition in the context of re-feeding programmes for moderate and severe acute malnutrition and as an indicator of the risk for obesity; (3) bioavailability and bioconversion of pro-vitamin A and vitamin A body stores following vitamin A intervention programmes; (4) absorption and retention of iron, zinc and protein; (5) total energy expenditure for validation of physical activity measurement and dietary assessment tools and (6) diagnosis of Helicobacter pylori. Stable isotope techniques will be invaluable in the tracking of global targets on exclusive breast-feeding childhood obesity and anaemia among women. Efforts are underway to make nuclear techniques more affordable, field-friendly and less invasive, and to develop less sophisticated but precise equipment. Advocacy for the wide adoption of the techniques is needed.

Acetate correction for postabsorption metabolism does not improve the [13C]mixed triacylglycerol breath test.

OBJECTIVE: The [C]mixed triacylglycerol (MTG) breath test is a noninvasive measure of fat digestion. After absorption and oxidation, C appears in breath CO2. Recovery is no more than 50% in healthy subjects because of sequestration of acetate in intermediary metabolism. The aims of this study were to investigate interindividual variation and postabsorptive metabolism of MTG using oral [1-C]acetate and to examine the use of correction factors to account for the "missing" label. PATIENTS AND METHODS: [C]mixed triacylglycerol and [1-C]acetate breath tests were performed on 8 healthy adults, 9 healthy children and 3 children with cystic fibrosis. Breath was sampled for 6 hours on each occasion. The enrichment of CO2 in breath was measured by isotope ratio mass spectrometry. Cumulative percentage dose recovered CO2 during the MTG test was corrected for label absorbed, but not completely oxidized using the cumulative percentage dose recovered during the acetate test. RESULTS: Mean recovery of C during the [C]MTG test with an acetate correction was close to 100% in healthy subjects: 103.1% (SD, 11.6%) in adults and 98.9% (SD, 30.3%) in children, but the wide variance indicated that some of the assumptions governing the use of acetate corrections with oral tracers may not be valid. CONCLUSION: The need to perform 2 tests, variation in physical activity between tests and differences in intermediary metabolism preclude the use of acetate correction factors when using [C]MTG to assess intraluminal fat digestion, especially in children.

Validity of Guatemalan Mother's Self-Reported Breast-Feeding Practices of 3-Month-Old Infants.

INTRODUCTION: Breast-feeding practices (BFPs) can be assessed by interviewing the mother about current feeding practices and with a 24-hour recall. It is crucial to establish the accuracy of these methods, which are commonly used by public health decision makers to design health policies aimed at increasing exclusive breast-feeding rates. OBJECTIVE: We aimed to validate 2 self-report BFP instruments using the dose-to-mother deuterium oxide turnover technique (DMDOT) as the reference method. METHODS: Breast-feeding practices were assessed by interviewing the mother about current feeding practices and with a 24-hour recall in 36 Guatemalan mother-infant pairs. The validity of these instruments was assessed using DMDOT as the reference method. RESULTS: Both self-report instruments overestimated exclusively breast-fed (EBF) infants. Infants classified as EBF were 50% by the reported current feeding practice, 61% by the 24-hour recall, and only 36% using DMDOT. Sensitivity to detect EBF infants from the mother's self-report was 92% (95% CI: 62%-99%) while from the 24-hour recall was 100% (95% CI: 72%-100%, P < .01). However, specificity for both instruments was low, at 74% (95% CI: 51%-89%) for reported current feeding practice and at 61% (95% CI: 39%-79%) for the 24-hour recall (P < .01). CONCLUSION: Both reported current feeding practice and the 24-hour recall instruments overestimated exclusive breast-feeding. Nevertheless, the use of reported current feeding practice provided more accurate data to assess BFPs in a public health setting. Furthermore, population-based surveys should consider the overestimation of exclusive breast-feeding caused when using these BFP instruments.

A simple prediction of total body water to aid quality control in isotope dilution studies in subjects 3-87 years of age.

The principal method of measuring total body water (TBW) is by isotope dilution. Also, the doubly labelled water method, which is the method of choice for measuring total energy expenditure (TEE) in free-living individuals, includes calculation of TBW as the dilution space of the tracer. TBW was measured in 261 subjects (135 males and 126 females), aged 3-87, including healthy children, children with HIV and adults with non-insulin dependent diabetes mellitus (type 2 diabetes), mild hypertension, pancreatic cancer and lung cancer, either in studies of body composition or TEE. A linear relationship was found between TBW and height in all subjects. When TBW is plotted against height cubed (Ht3, m3) the regression line can be forced through the origin. Considering only adults with 18.5>body mass index <29.9 and all children (n=220), this yielded TBW (l)=7.40 x Ht3, R2=0.95. This simple linear relationship between measured TBW and Ht3 compared favourably with other prediction methods, assuming TBW is a constant proportion (55%) of body weight and TBW predicted from height and weight (mean difference between measured and predicted TBW 0.55 l compared with -1.95 and -1.20 l, respectively). Absolute errors were greater at higher TBW, but use of a log10 transformation reduced this effect. This simple relationship of TBW with Ht3 is too crude to be used as a body composition predictor in individual subjects as it ignores, for instance, body shape. However, it can be used as a quality control tool. Here, use of a log10 transformation and residual plot can serve to identify outliers, which can be checked for gross errors in data input and if necessary samples are re-analysed.

Relation between physical activity and energy expenditure in a representative sample of young children.

BACKGROUND: Strategies for the prevention and treatment of childhood obesity require a better understanding of the relation between the pattern of free-living physical activity and total energy expenditure (TEE). OBJECTIVE: We assessed the relations between TEE and physical activity level (PAL) during engagement in different intensities of physical activity. DESIGN: We used a cross-sectional study of 104 children (median age: 5.4 y) in Scotland. TEE was measured with use of doubly labeled water (DLW), and resting energy expenditure was predicted to determine PAL. Time spent sedentary and in light-intensity activity and in moderate- and vigorous-intensity physical activity (MVPA) was assessed by accelerometry concurrent with DLW measurements. Correlation and regression were used to assess the relations between measures of sedentary behavior, intensities of activity, and PAL as the dependent variable. RESULTS: Time spent sedentary was negatively correlated with PAL (r = -0.33, P < 0.01), and time spent in light-intensity activity was positively correlated with PAL (r = 0.31, P < 0.01). In multiple regression analyses, both time spent sedentary and in light-intensity activities were significantly associated with PAL. Time spent in MVPA was not associated with PAL; engagement in MVPA was limited in this sample (median: 3% of waking hours; range: 0-14%). PAL was significantly higher in boys than in girls. CONCLUSION: In this sample and setting, PAL was not influenced by engagement in MVPA but was influenced by time spent sedentary and in light-intensity activities. This study suggests that in young children, MVPA could make only a minor contribution to free-living TEE and PAL.

Bulk and compound specific analysis of stool lipid confirm that the "missing" 13C in the mixed triacylglycerol breath test is not in the stool.

The 13C-mixed triacylglycerol (MTG) breath test is used to measure intraluminal fat digestion. In normal digestion 20% to 40% of the ingested 13C label is recovered in breath CO2. We aimed to identify the proportions of ingested label excreted in stool as well as breath following ingestion of 13C-MTG by children with impaired exocrine pancreatic function and healthy controls. 13C enrichment of breath samples was measured by continuous flow isotope ratio mass spectrometry (IRMS) and the cumulative percent dose recovered (cPDR) in 10 hours was calculated. Total 13C of a fecal fat extract from each stool was measured by combustion-IRMS, and 13C enrichment and concentration of the tert.-butyldimethylsilyl (TBDMS) derivative of octanoic acid was measured by gas chromatography-mass spectrometry (GC/MS) after hydrolysis of the fat extract. Stool 5-day cPDR was calculated. Mean breath cPDR was 33% for children with cystic fibrosis and 45% for controls. Mean cPDR in stool by combustion-IRMS and GC/MS, respectively, was 0.7% and 0.3% for children with cystic fibrosis and 1.4 and 4.2% for controls.