Can hormones contained in mothers' milk account for the beneficial effect of breast-feeding on obesity in children?

Bioactive Components of Human Milk and Their Impact on Child's Health and Development, Literature Review

The composition of human breast milk is an ideal combination of substances necessary for the healthy development of an infant's body while protecting from pathogens and the balanced development of the microbiota. Its composition is dynamic and changes with the age of the child, meeting their current needs. The study provides a thorough overview of human milk components, such as immunological components, growth factors, hormones, carbohydrates, lipids, minerals, and vitamins. Authors focus on capturing the most important aspects of the effects of these substances on a newborn's body, while also looking for specific connections and describing the effects on given systems. Supplementation and the use of ingredients are also discussed. The purpose of this paper is to present the current state of knowledge about the bioactive components of human milk and their impact on the growth, development, and health of the young child.

Early Infant Feeding Practices and Associations with Growth in Childhood

Early infant growth trajectories have been linked to obesity risk. The aim of this study was to examine early infant feeding practices in association with anthropometric measures and risk of overweight/obesity in childhood. A total of 2492 children from Upstate KIDS, a population-based longitudinal cohort, were included for the analysis. Parents reported breastfeeding and complementary food introduction from 4 to 12 months on questionnaires. Weight and height were reported at 2-3 years of age and during later follow-up at 7-9 years of age. Age and sex z-scores were calculated. Linear mixed models were conducted, adjusting for maternal and child sociodemographic factors. Approximately 54% of infants were formula-fed at <5 months of age. Compared to those formula-fed, BMI- (adjusted B, -0.23; 95% CI: -0.42, -0.05) and weight-for-age z-scores (adjusted B, -0.16; -0.28, -0.03) were lower for those exclusively breastfed. Infants breastfed for ≥12 months had a lower risk of being overweight (aRR, 0.33; 0.18, 0.59) at 2-3 years, relative to formula-fed infants. Compared to introduction at <5 months, the introduction of fruits and vegetables between 5 and 8 months was associated with lower risk of obesity at 7-9 years (aRR, 0.45; 0.22, 0.93). The type and duration of breastfeeding and delayed introduction of certain complementary foods was associated with lower childhood BMI.

Relationship between lipid profile, anthropometric indicators, and appetite-regulating hormones in infants according to type of feeding

Introduction

Background: infants receiving full breastfeeding (FBF) regulate their appetites differently from those receiving human milk substitutes (HMS). In addition, early exposure to the dietary cholesterol in human milk could lead to better cholesterol regulation in later stages of life. Therefore, the purpose was to compare lipid profiles in 4-month-old infants and to correlate lipid profile with anthropometric indicators and appetite-regulating hormones according to the type of feeding. Methods: this was a cross-sectional and correlational study, which included 145 mother-infant dyads according to the type of feeding; 64 received FBF, 47 partial breastfeeding (PBF), and 34 HMS. The complete lipid profile, total ghrelin, leptin, peptide YY, and glucagon-like peptide type 1 were measured. Z-scores for weight/age, length/age, weight/length, triceps (TSF) and subscapular folds (SSF) and body mass index for age were also obtained. Results: there were significant differences in triglycerides and LDL cholesterol according to the type of feeding. In the HMS group, an inverse relationship was observed between ghrelin and triglycerides (p = 0.038), ghrelin and total cholesterol (TC) (p = 0.026), and peptide YY and HDL cholesterol (p = 0.017). In the PBF group, a direct relationship was observed between length/age (z) and triglycerides (p = 0.001) and between subscapular folds and TC (p = 0.049). In infants receiving HMS, a direct correlation was observed between weight/age (z) and TC (p = 0.045) and between length/age (z) and LDL cholesterol (p = 0.010). Conclusion: these findings show a relationship between growth, energy reserve, lipid profile, and modulation of appetite-regulating hormones according to the type of feeding they received.

Maternal and health care workers' perspectives on exclusive breastfeeding in the context of maternal HIV infection, in Busia county, western Kenya: a mixed methods cross-sectional survey

BACKGROUND

World Health Organization recommends exclusive breastfeeding (EBF) for 6 months with maternal active antiretroviral therapy (ART) to prevent mother-to-child transmission (PMTCT) of HIV. However, EBF in low resource settings remains low. We explored perspectives of EBF by HIV-infected mothers and health care workers in Busia County with a high prevalence of HIV to understand factors influencing the practice.

METHODS

A mixed methods cross-sectional survey using concurrent quantitative and qualitative data collection methods was conducted at PMTCT clinics. Data on socio-demography, young infant feeding practices, maternal and infant health was collected between February 2013 and August 2015 from 371 purposively sampled HIV-infected mother-infant dyads using a semi-structured questionnaire. Focus group discussions with mothers, in-depth interviews and passive observation of health care workers during interaction with mothers were conducted. Significance of difference between mothers practicing EBF or not was tested by Chi-square and Fisher's exact tests setting significance level at 5%. Qualitative data was coded and content analyzed to generate themes.

RESULTS

Three hundred and forty-nine (94%) mothers practiced EBF. Maternal comprehension of EBF to PMTCT of HIV influenced choice and practice of EBF (P value = 0.019 and < 0.001 respectively). Health care workers emphasized adherence to ART and offered nutritional supplementation during EBF. Health care workers' nutritional counseling in the context of maternal HIV was poor. Mentor mothers shared their experiences with mothers and offered live case demonstrations of their successfully EBF, healthy and HIV-uninfected children. The main threats to EBF were teenage motherhood, low maternal education and working during EBF.

CONCLUSIONS

EBF among HIV-infected mothers in Busia County, Kenya was high. Health education and counselling by health care workers, maternal comprehension of ART adherence to PMTCT of HIV, nutritional supplementation and mentor mothers' peer counseling using live case demonstrations of HIV-uninfected EBF children promoted and sustained practice of EBF for 6 months. Teenage motherhood, low maternal education and having to work threatened EBF.

Resistin in Urine and Breast Milk: Relation to Type of Feeding and Anthropometry at 1-Month

Breast milk contains adipokines such as resistin and leptin and is known for its protective effect against obesity and insulin resistance. This pilot study aims to evaluate the correlation between resistin levels, feeding types (breast milk and formula), and anthropometric parameters in healthy 1-month-old term infants. Urine and breast milk samples were collected from 32 infants and their mothers at 1 month postpartum. Twelve infants were included in the breastfed group, while thirteen infants comprised the breastfed-dominant mix-fed group, and seven infants the formula-dominant mix-fed group. Using ELISA kits, we analyzed resistin levels in the infants' urine and the mothers' breast milk, and leptin levels in breast milk. Urinary resistin levels among the three groups were not significantly different. There was no correlation between the following: urinary resistin levels in the breastfed group with resistin levels in breast milk; resistin levels in urine with infant's body weight and weight gain; resistin levels in breast milk with weight, age, and BMI of mothers and leptin levels in breast milk. This study suggests that the type of feeding does not affect resistin levels in term infants and resistin level does not affect growth in early infancy.

Maternal vaccination as an additional approach to improve the protection of the nursling: Anti-infective properties of breast milk

Human milk constitutes a secretion with unique functions of both nourishing the nursling and providing protection against enteric and respiratory infections, mainly due to its content of secretory IgA antibodies but also due to the presence of a plethora of bioactive factors. Specific IgA antibodies are produced locally by plasma cells derived from B lymphocytes that migrate from other mucosae to the mammary gland during lactation, particularly from the gastrointestinal and respiratory tracts. Therefore, here, the authors will provide a comprehensive review of the content and functions of different nutritional and bioactive anti-infectious components from breast milk, such as oligosaccharides, lactoferrin, haptocorrin, α-lactalbumin, k-casein, lysozyme, lactoperoxidase, mucin, fatty acids, defensins, cytokines and chemokines, hormones and growth factors, complement proteins, leukocytes and nucleic acids, including microRNAs, among many others, and the induction of antibody responses in breast milk after maternal vaccination with several licensed vaccines, including the anti-SARS-CoV-2 vaccine preparations used worldwide. Currently, in the midst of the pandemic, maternal vaccination has re-emerged as a crucial source of passive immunity to the neonate through the placenta and breastfeeding, considering that maternal vaccination can induce specific antibodies if performed during pregnancy and after delivery. There have been some reports in the literature about milk IgA antibodies induced by bacterial antigens or inactivated virus vaccines, such as anti-diphtheria-tetanus-pertussis, anti-influenza viruses, anti-pneumococcal and meningococcal polysaccharide preparations. Regarding anti-SARS-CoV-2 vaccines, most studies demonstrate elevated levels of specific IgA and IgG antibodies in milk with virus-neutralizing ability after maternal vaccination, which represents an additional approach to improve the protection of the nursling during the entire breastfeeding period.

Infant feeding, appetite and satiety regulation, and adiposity during infancy: a study design and protocol of the 'MAS-Lactancia' birth cohort

INTRODUCTION

The prevalence of childhood obesity has risen dramatically in recent years. A proportion of this burden has been attributed to factors that occur during the first 1000 days of life such as genetic predisposition, breast feeding and complementary feeding. Although the mechanisms by which these factors affect weight and adiposity are less well understood, appetite and satiety regulation may be a key to understanding them. This cohort study aims to investigate the role of appetite and satiety regulation as a mediator in the association between infant feeding practices and genetic polymorphisms with children's growth, adiposity and metabolic risk factors. METHODS AND ANALYSIS: 'MAS-Lactancia' (the first word means 'more' and is also an acronym in Spanish for 'Appetite and Satiety Mechanisms', the second word is 'breastfeeding') is an open, ongoing, prospective birth cohort that began the enrolment in 2016 of mother-child pairs affiliated to the Mexican Social Security Institute and that live in the city of Cuernavaca, Mexico. Pregnant women between 16-week and 22-week gestation are followed during the second half of their pregnancies, at birth and throughout their infant's first 48 months of life (at 1 month, 3 months, 6 months, 9 months, 12 months, 18 months, 24 months, 36 months and 48 months) at the clinic and at-home visits that include questionnaires, anthropometric measurements and biospecimen collection. The main exposure variables are infant feeding (breast feeding and complementary feeding) and genetic polymorphisms (fat mass and obesity-associated, leptin and adiponectin genes). Outcome variables include infant's growth, adiposity and metabolic risk factors. We will conduct longitudinal models and path analyses to identify the potential mediating role of satiety and appetite indicators (leptin, adiponectin, insulin concentrations, appetite and satiety perception).

ETHICS AND DISSEMINATION

The study protocol, data collection instruments, consent forms and procedures were approved by the institutional review boards of the National Institute of Public Health and the Mexican Social Security Institute in Mexico. Findings will be disseminated through conferences, peer-reviewed publications and meetings with stakeholders.

Metabolic Conditions Including Obesity, Diabetes, and Polycystic Ovary Syndrome: Implications for Breastfeeding and Breastmilk Composition

Breastfeeding is internationally recognized as the recommended standard for infant nutrition, informed by evidence of its multiple benefits for both mother and baby. In the context of common metabolic conditions such as polycystic ovary syndrome, diabetes (type 1, type 2, and gestational), and obesity, breastfeeding may be particularly beneficial for both mother and infant. However, there is evidence of delayed lactogenesis and reduced breastfeeding rates and duration in women with these conditions, and the effects of altered maternal metabolic environments on breastmilk composition (and potentially infant outcomes) are incompletely understood. In this review, we explore the relationships between maternal metabolic conditions, lactogenesis, breastfeeding, and breastmilk composition. We examine relevant potential mechanisms, including the central role of insulin both in lactogenesis and as a milk-borne hormone. We also describe the bioactive and hormonal components of breastmilk and how these may link maternal and infant health.

Appetite-Regulating Hormones in Human Milk: A Plausible Biological Factor for Obesity Risk Reduction?

BACKGROUND

Human milk contains appetite-regulating hormones that may influence infant growth and obesity risk.

RESEARCH AIMS

We evaluated whether leptin, peptide tyrosine-tyrosine (PYY), glucagon-like peptide-1 (GLP-1), and ghrelin concentrations in human milk (1) changed during feeding (from foremilk to hindmilk) and during the first 6 months of infancy; (2) were explained by maternal factors; and (3) were associated with infant anthropometrics and growth.

METHODS

Mother-infant dyads (N = 22) participated. Samples of foremilk and hindmilk at 1 month postpartum were collected and analyzed for leptin, PYY, GLP-1, and ghrelin via radioimmunoassay and milkfat percentage estimated via creamatocrit. Samples were also collected in mothers (n = 15) who breastfed through 6 months. Anthropometrics were obtained on all mother-infant dyads at 1 month and all infants at 6 months and 12 months.

RESULTS

At 1 month, milk GLP-1 and milkfat concentration increased from foremilk to hindmilk (p ≤ .05) while leptin and PYY concentrations remained stable during feeding. Milk hormone concentrations and milkfat tended to decline overtime, with lower leptin, PYY, and ghrelin at 6 months versus 1 month (p < .05). At 1 month, milk leptin and milkfat content were associated with maternal markers of adiposity (r = 0.49-0.78, p < .001); whereas, milk PYY was correlated with maternal serum PYY concentration (r = 0.672, p = .001). Average 1-month milk concentrations of GLP-1 and leptin were negatively associated with weight-for-age z-scores at 6 months (r = -0.46, p < .05) and 12 months (r = -0.49, p < .05), respectively.

CONCLUSION

The content of certain appetite-regulating hormones in human milk may be influenced by maternal factors and play a role in infant growth; much needs to be learned about their role in the obesity protection of breastfed infants.

Maternal High-Fat Diet Exposure During Gestation and Lactation Affects Intestinal Development in Suckling Rats

Maternal health and diet influence metabolic status and play a crucial role in the development of metabolic function in offspring and their susceptibility to metabolic diseases in adulthood. The pathogenesis of various metabolic disorders is often associated with impairment in intestinal structure and function. Thus, the aim of the current study was to determine the effects of maternal exposure to a high fat diet (HFD), during gestation and lactation, on small intestinal growth and maturation in rat pups at 21 days old. Female, Wistar Han rats were fed either a breeding diet (BD) or high fat diet (HFD), from mating until the 21st day of lactation. Maternal HFD exposure increased body weight, BMI and adiposity. Compared to the maternal BD, HFD exposure influenced small intestine histomorphometry in a segment-dependent manner, changed the activity of brush border enzymes and had an impact on intestinal contractility via changes in cholinergic signaling. Moreover, offspring from the maternal HFD group had upregulated mRNA expression of cyclooxygenase (COX)-2, which plays a role in the inflammatory process. These results suggest that maternal HFD exposure, during gestation and lactation, programs the intestinal development of the offspring in a direction toward obesity as observed changes are also commonly reported in models of diet-induced obesity. The results also highlight the importance of maternal diet preferences in the process of developmental programming of metabolic diseases.

Metabolic Hormone Profiles in Breast Milk From Mothers of Moderate-Late Preterm Infants Are Associated With Growth From Birth to 4 Months in a Sex-Specific Manner

Background: Differing environmental conditions experienced by mother-infant dyads may influence composition of the milk received by the infant. As a consequence, diverse milk compositional profiles may contribute to different postnatal outcomes, especially in infants facing adverse perinatal environments. We investigated whether variability in milk concentrations of key metabolic hormones is associated with different growth outcomes in infants born preterm, a perinatal complication known to impact on infant growth. Methods: Human milk samples were collected from 169 mothers of 191 infants enrolled in the DIAMOND trial, a randomized trial of nutrition for moderate-late preterm infants, at 5 and 10 days postpartum and again at 4 months' corrected age and analyzed for leptin, adiponectin and insulin-like growth factor (IGF)-1. Infant weight and body composition were measured at birth, discharge and 4 months' corrected age. Multiple linear regression models were used to examine correlations between milk hormone concentrations, weight z-scores and body composition at discharge and 4 months' corrected age, and weight gain from birth to 4 months' corrected age. Sex-specific interactions were examined. Results: Higher milk IGF-1 concentrations on day 5 after birth were associated with greater infant fat-free mass at 4 months' corrected age. Milk IGF-1 concentrations at 4 months were positively associated with fat mass and fat-free mass at 4 months in boys but not girls. Milk leptin concentrations on day 5 after birth were positively associated with fat mass at discharge from hospital, but negatively associated with fat mass at 4 months' corrected age. No significant association was found for milk adiponectin concentrations. Conclusion: Milk IGF-1 and leptin concentrations in mothers of moderate-late preterm babies are associated with different growth and body composition through to 4 months' corrected age and these associations are often different in boys and girls. The sex-specific effects of nutrient and hormone exposure during early life in preterm infants warrants further investigation to optimize the nutritional care these infants receive, particularly in hospital, where the same nutrition is provided to boys and girls.

Association between breast milk adipokines with growth in breast feeding infants, a systematic review and meta-analysis

Objectives

Breast milk adipokines are associated with growth, body mass index (BMI) and weight gain in infants. In this study, the effect of breastmilk adipokines (leptin and adiponectin) on the BMI and weight gain of breast-fed infants was evaluated using systematic review and meta-analysis.

Materials and methods

We used PRISMA checklist for carrying out this study. 752 articles were collected from the database searching and other sources from 1994 to April 2019. According to the criteria in the study, 25 articles remained for evaluation. Eight papers were related to the effect of breast milk leptin on weight gain and BMI of infants that were evaluated by meta-analyzing. The adiponectin articles were surveyed by systematic review.

Results

There was no significant publication bias in the meta-analysis study. The results of random-effect model indicated a reverse and significant correlation between breastmilk leptin with weight gain and BMI (r=−0.331). The adiponectin level in breast milk was associated with the BMI and weight gain of infants.

Conclusions

Meta-analysis indicated a significant inverse correlation between breastmilk leptin with weight gain and BMI in infants; furthermore, the systematic review study expressed significant correlation between breast milk adiponectin with growth (BMI and weight gain) in infants.

Breastfeeding predicts blood mitochondrial DNA content in adolescents

Nutrition during early childhood is linked to metabolic programming. We hypothesized that breastfeeding has long-term consequences on the energy metabolism exemplified by mitochondrial DNA (mtDNA). As part of the third cycle of the Flemish Environment and Health Study (FLEHSIII) cohort, 303 adolescents aged 14–15 years were included. We associated breastfeeding and blood mtDNA content 14–15 years later while adjusting for confounding variables. Compared with non-breastfed adolescents, mtDNA content was 23.1% (95%CI: 4.4–45.2; p = 0.013) higher in breastfed adolescents. Being breastfed for 1–10 weeks, 11–20 weeks, and >20 weeks, was associated with a higher mtDNA content of respectively 16.0% (95%CI: −7.1–44.9; p = 0.191), 23.5% (95%CI: 0.8–51.3; p = 0.042), and 31.5% (95%CI: 4.3–65.7; p = 0.021). Our study showed a positive association between breastfeeding and mtDNA content in adolescents which gradually increased with longer periods of breastfeeding. Higher mtDNA content may be an underlying mechanism of the beneficial effects of breastfeeding on children’s metabolism.

Breast milk alkylglycerols sustain beige adipocytes through adipose tissue macrophages

Prevalence of obesity among infants and children below 5 years of age is rising dramatically, and early childhood obesity is a forerunner of obesity and obesity-associated diseases in adulthood. Childhood obesity is hence one of the most serious public health challenges today. Here, we have identified a mother-to-child lipid signaling that protects from obesity. We have found that breast milk-specific lipid species, so-called alkylglycerol-type (AKG-type) ether lipids, which are absent from infant formula and adult-type diets, maintain beige adipose tissue (BeAT) in the infant and impede the transformation of BeAT into lipid-storing white adipose tissue (WAT). Breast milk AKGs are metabolized by adipose tissue macrophages (ATMs) to platelet-activating factor (PAF), which ultimately activates IL-6/STAT3 signaling in adipocytes and triggers BeAT development in the infant. Accordingly, lack of AKG intake in infancy leads to a premature loss of BeAT and increases fat accumulation. AKG signaling is specific for infants and is inactivated in adulthood. However, in obese adipose tissue, ATMs regain their ability to metabolize AKGs, which reduces obesity. In summary, AKGs are specific lipid signals of breast milk that are essential for healthy adipose tissue development.

Maternal high-fat diet exposure during gestation, lactation, or gestation and lactation differentially affects intestinal morphology and proteome of neonatal mice

Offspring nutrition depends on the mother during gestation and lactation; thus, maternal nutrition and metabolism can affect their development. We hypothesized that maternal exposure to high-fat (HF) diet affects neonate's gastrointestinal tract development. Our objective was to determine the effect of maternal HF diet during gestation and lactation on neonate's duodenum histomorphology and proteome. Female mice were fed either a control (C, 10% kcal fat) or an HF (60% kcal fat) diet for 4 weeks and bred. On postnatal day 2, half the pups were cross-fostered to dams fed on different diet, creating 4 treatments: C-C, C-HF, HF-C, and HF-HF, indicating maternal diet during gestation-lactation, respectively. On postnatal day 12, pups' duodenum was excised and prepared for histology and liquid chromatography-tandem mass spectrometry analysis of proteome. Villi were significantly longer in HF-HF pups, and crypt cell proliferation rate was not different among treatments. Between C-C and HF-HF, HF-C, or C-HF, 812, 601, or 894 proteins were differentially expressed (Tukey adjusted P < .05), respectively. Functional analysis clustered proteins upregulated in HF-HF vs C-C in fat digestion and absorption, extracellular matrix, cell adhesion, immune response, oxidation-reduction processes, phagocytosis, and transport categories. Proteins downregulated were classified as RNA splicing, translation, protein folding, endocytosis, and transport. There was evidence for a carryover effect of exposure to HF diet during gestation to the postnatal period. Alterations in proteome relative to HF exposure potentially reflect long-term changes in the functioning of the duodenum.

Associations of breast milk adiponectin, leptin, insulin and ghrelin with maternal characteristics and early infant growth: a longitudinal study

Breast milk (BM) hormones have been hypothesised as a nutritional link between maternal and infant metabolic health. This study aimed to evaluate hormone concentrations in BM of women with and without gestational diabetes mellitus (GDM), and the relationship between maternal factors, BM hormones and infant growth. We studied ninety-six nulliparous women with (n 48) and without GDM and their exclusively breastfed term singletons. Women with GDM received dietary therapy or insulin injection for euglycaemia during pregnancy. Hormone concentrations in BM, maternal BMI and infant growth were longitudinally evaluated on postnatal days 3, 42 and 90. Mothers with GDM had decreased concentrations of adiponectin (P colostrum<0·001; P mature-milk=0·009) and ghrelin (P colostrum=0·011; P mature-milk<0·001) and increased concentration of insulin in BM (P colostrum=0·047; P mature-milk=0·021). Maternal BMI was positively associated with adiponectin (β=0·06; 95 % CI 0·02, 0·1; P=0·001), leptin (β=0·16; 95 % CI 0·12, 0·2; P<0·001) and insulin concentrations (β=0·06; 95 % CI 0·02, 0·1; P<0·001), and inversely associated with ghrelin concentration in BM (β=-0·08; 95 % CI -0·1, -0·06; P<0·001). Among the four hormones, adiponectin was inversely associated with infant growth in both the GDM (β weight-for-height=-2·49; 95 % CI -3·83, -1·15; P<0·001; β head-circumference=-0·39; 95 % CI -0·65, -0·13; P=0·003) and healthy groups (β weight-for-height=-1·42; 95 % CI -2·38, -0·46; P=0·003; β head-circumference=-0·15; 95 % CI -0·27, -0·03; P=0·007). Maternal BMI and GDM are important determinants of BM hormone concentrations. Milk-borne adiponectin is determined by maternal metabolic status and plays an independent down-regulating role in early infant growth.

Infant breastfeeding and childhood general, visceral, liver, and pericardial fat measures assessed by magnetic resonance imaging

Background

Although a longer duration of breastfeeding has been associated with a lower risk of childhood obesity, the impact on specific organ fat depots is largely unknown.

Objective

We examined the associations of any breastfeeding, duration and exclusiveness of breastfeeding, and of age at introduction of solid foods with measures of general, visceral, and organ adiposity at 10 y.

Design

In a population-based prospective cohort study in 4444 children, we obtained information on infant feeding by questionnaires. At the mean age of 9.8 y, we estimated body mass index from height and weight; fat mass index and fat-free mass index by dual-energy X-ray absorptiometry; and visceral fat index, pericardial fat index, and liver fat fraction by MRI. MRI scans were performed in a subgroup of 2646 children.

Results

After adjustment for age and sex, we observed associations of infant feeding with all general, visceral, and organ fat outcomes, except for pericardial fat index, at the age of 10 y. After further adjustment for family-based sociodemographic, maternal lifestyle-related, and childhood factors, only the associations of shorter breastfeeding duration and nonexclusive breastfeeding with a lower fat-free mass index remained significant (P < 0.05). The associations of infant feeding with visceral fat index and liver fat fraction were attenuated to nonsignificant. Maternal education was found to be the strongest confounder.

Conclusion

Our results suggest that the assoiations of any breastfeeding, duration and exclusiveness of breastfeeding, and age at the introduction of solid foods with general, visceral, and organ fat measures at the age of 10 y are largely explained by family-based sociodemographic factors.

Maternal Serum and Breast Milk Adiponectin: The Association with Infant Adiposity Development

The prevalence of childhood obesity is increasing at an alarming rate in Malaysia. Metabolic changes during pregnancy are critical to the development of infant adiposity, due to imbalanced adipokines production. Hence, we aimed to investigate the association of maternal serum and breast milk adipokines with infant adiposity development. The study was conducted from April 2010 until December 2012. A total of 155 healthy pregnant mothers aged 19 to 40 years were recruited during the first and second trimester in Kelantan, Malaysia. Data consisted of maternal sociodemographic details, anthropometry and clinical biochemistry analysis; and the infant’s anthropometry and feeding patterns. Maternal fasting serum and breast milk samples were analysed for adiponectin and leptin levels. Data collection was performed in the second and third trimester of pregnancy, and continued with follow-up visits at birth, two, six, and 12 months postpartum. Multiple linear regression (MLR) analyses were performed to examine the associations between maternal serum and breast milk adiponectin and leptin and infant adiposity development. MLR models showed that, in the first year, as maternal serum and breast milk adiponectin increased, infant weight, BMI-for-age Z scores and abdominal circumference significantly decreased (p < 0.05). Maternal serum and/or breast milk adiponectin was associated with first-year infant adiposity development.

[Association of leptin, adiponectin, and ghrelin in breast milk with the growth of infants with exclusive breastfeeding]

OBJECTIVE

To investigate the association of leptin, adiponectin, and ghrelin in breast milk with the weight growth velocity of infants with exclusive breastfeeding.

METHODS

A total of 67 full-term singleton infants who received regular child care and exclusive breastfeeding and their mothers were enrolled. The nutritional status was evaluated based on the measurements of body weight and body length (underweight, growth retardation, emaciation, overweight, and obesity). Z score was used to calculate growth velocity, and according to the ΔZ score, the infants were divided into poor growth group, low growth velocity group, and normal growth velocity group. Mature breast milk samples were collected from their mothers, and ELISA was used to measure the levels of leptin, adiponectin, and ghrelin.

RESULTS

The emaciation group had a significantly lower level of leptin in breast milk than the non-emaciation group (P<0.05), and the overweight/obesity group had a significantly lower level of adiponectin than the non-overweight/obesity group (P<0.05). The correlation analysis showed that the level of ghrelin in breast milk was positively correlated with Z score of current body weight and ΔZ score compared with birth weight (r_s=0.280 and 0.290 respectively; P<0.05). The regression analysis showed that the level of ghrelin in breast milk was an important influencing factor for the Z score of body weight (β=0.161, P<0.05).

CONCLUSIONS

Various active constituents in breast milk, including leptin, adiponectin, and ghrelin, may regulate the growth and development of infants to a certain degree, but long-term studies and observation are needed to investigate their association with offspring growth and development and the health-promoting effect of breast milk on offspring.

Associations of Maternal Weight Status Before, During, and After Pregnancy with Inflammatory Markers in Breast Milk

OBJECTIVE

The goal of this study was to examine the associations of maternal weight status before, during, and after pregnancy with breast milk C-reactive protein (CRP) and interleukin 6 (IL-6), two bioactive markers of inflammation, measured at 1 and 3 months post partum.

METHODS

Participants were 134 exclusively breastfeeding mother-infant dyads taking part in the Mothers and Infants Linked for Health (MILK) study, who provided breast milk samples. Pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) were assessed by chart abstraction; postpartum weight loss was measured at the 1- and 3-month study visits. Linear regression was used to examine the associations of maternal weight status with repeated measures of breast milk CRP and IL-6 at 1 and 3 months, after adjustment for potential confounders.

RESULTS

Pre-pregnancy BMI and excessive GWG, but not total GWG or postpartum weight loss, were independently associated with breast milk CRP after adjustment (β = 0.49, P < 0.001 and β = 0.51, P = 0.011, respectively). No associations were observed for IL-6.

CONCLUSIONS

High pre-pregnancy BMI and excessive GWG are associated with elevated levels of breast milk CRP. The consequences of infants receiving varying concentrations of breast milk inflammatory markers are unknown; however, it is speculated that there are implications for the intergenerational transmission of disease risk.

Nutrition (Micronutrients) in Child Growth and Development: A Systematic Review on Current Evidence, Recommendations and Opportunities for Further Research

OBJECTIVE

An important aspect of malnutrition is deficiency of different micronutrients during pregnancy or early childhood. We systematically reviewed the role of nutrition in child growth (weight or height gain) and development.

METHODS

A comprehensive literature search was done on PubMed/Cochrane Library browsing through 38,795 abstracts until December 31, 2016 to select systematic reviews/meta-analyses and individual randomized controlled trials (RCTs) of micronutrient supplementation.

RESULTS

Micronutrients studied included iron, iodine, folate, zinc, calcium, magnesium, selenium, vitamin D, vitamin A, vitamin B complex, and multiple micronutrients. We summarize evidence with details and results of RCTs, highlight strengths/weaknesses, and critically interpret findings. Effects of breastfeeding-promotion, food-supplementation (complementary and school feeding), conditional-cash-transfers, and integrated nutrition/psychosocial interventions are discussed.

CONCLUSION

Based on this evidence we make policy and programmatic recommendations for supplementation to mothers and children at high-risk of deficiency.

Associations between human breast milk hormones and adipocytokines and infant growth and body composition in the first 6 months of life

BACKGROUND

Much is to be learnt about human breast milk (HBM).

OBJECTIVES

The purpose of this study is to extend our knowledge of HBM by investigating the role of maternal body mass index (BMI), sex and stage of lactation (month 1 vs. 6) on HBM insulin, glucose, leptin, IL-6 and TNF-α and their associations with infant body composition.

METHODS

Thirty-seven exclusively breastfeeding infants (n = 37; 16♀, 21♂), and their mothers (19-47 kg m^-2 ) were studied at 1 and 6 months of lactation. Infants had body composition measured (using dual-energy X-ray absorptiometry) and HBM collected.

RESULTS

A significant interaction between maternal BMI and infant sex on insulin levels (p = 0.0322) was observed such that insulin was 229% higher in obese mothers nursing female infants than in normal weight mothers nursing female infants and 179% higher than obese mothers nursing male infants. For leptin, a significant association with BMI category was observed (p < 0.0001) such that overweight and obese mothers had 96.5% and 315.1% higher leptin levels than normal weight mothers, respectively. Leptin was also found to have a significant (p = 0.0004) 33.7% decrease from months 1 to 6, controlling for BMI category and sex. A significant inverse relationship between month 1 leptin levels and infant length (p = 0.0257), percent fat (p = 0.0223), total fat mass (p = 0.0226) and trunk fat mass (p = 0.0111) at month 6 was also found. No associations or interactions were observed for glucose, TNF-α or IL-6.

CONCLUSIONS

These data demonstrate that maternal BMI, infant sex and stage of lactation affect the compositional make-up of insulin and leptin.

Infant feeding and growth trajectory patterns in childhood and body composition in young adulthood

Background: Growth patterns of breastfed and formula-fed infants may differ, with formula-fed infants growing more rapidly than breastfed infants into childhood and adulthood.Objective: Our objectives were to identify growth patterns and investigate early nutritional programming potential on growth patterns at 6 y and on body composition at 20 y.Design: The West Australian Pregnancy Cohort (Raine) Study and 3 European cohort studies (European Childhood Obesity Trial, Norwegian Human Milk Study, and Prevention of Coeliac Disease) that collaborate in the European Union-funded Early Nutrition project combined, harmonized, and pooled data on full breastfeeding, anthropometry, and body composition. Latent growth mixture modeling was applied to identify growth patterns among the 6708 individual growth trajectories. The association of full breastfeeding for <3 mo compared with ≥3 mo with the identified trajectory classes was assessed by logistic regression. Differences in body composition at 20 y among the identified trajectory classes were tested by analysis of variance.Results: Three body mass index (BMI; in kg/m²) trajectory patterns were identified and labeled as follows-class 1: persistent, accelerating, rapid growth (5%); class 2: early, nonpersistent, rapid growth (40%); and class 3: normative growth (55%). A shorter duration of full breastfeeding for <3 mo was associated with being in rapid-growth class 1 (OR: 2.66; 95% CI: 1.48, 4.79) and class 2 (OR: 1.96; 95% CI: 1.51, 2.55) rather than the normative-growth class 3 after adjustment for covariates. Both rapid-growth classes showed significant associations with body composition at 20 y (P < 0.0001).Conclusions: Full breastfeeding for <3 mo compared with ≥3 mo may be associated with rapid growth in early childhood and body composition in young adulthood. Rapid-growth patterns in early childhood could be a mediating link between infant feeding and long-term obesity risk.

Variation of Metabolite and Hormone Contents in Human Milk

Animal studies show that the lactation period contributes to metabolic programming of the offspring and that oral leptin and insulin show bioactivity. Stage of lactation, duration of gestation, maternal body composition, and maternal diet seem to influence the concentrations of small molecules in human milk. Variability of small molecule concentrations seems higher in preterm milk than in term milk. Insulin in human milk shows concentrations similar to plasma. Leptin concentration is lower in milk than in plasma and reflects maternal body mass index. Early in lactation, leptin could contribute to mediating the association between maternal and infant body composition.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Free Amino Acids in Human Milk and Associations With Maternal Anthropometry and Infant Growth

OBJECTIVES

Free glutamic acid has an appetite-regulating effect and studies with infant formula have suggested that free amino acids (FAA), especially glutamic acid, can downregulate intake. The content of glutamic acid and glutamine is high in breast milk but varies considerably between mothers. The aim was to investigate whether maternal anthropometry was associated with the content of the FAA glutamic acid or glutamine in breast milk and whether there was a negative association between these FAA and current size or early infant growth in fully breastfed infants.

METHODS

From a subgroup of 78 mothers, of which 50 were fully breast feeding, from the Odense Child Cohort breast milk samples were collected 4 months after birth and analyzed for FAA. Information regarding breastfeeding status and infant weight and length was also recorded.

RESULTS

There was a large variation in the concentration of the FAAs between mothers. Glutamic acid was positively correlated with mother's prepregnancy weight and height (P ≤ 0.028), but not body mass index. There was no negative correlation between the 2 FAA and infant weight or body mass index. Infant length at 4 months was, however, positively associated with glutamine, (P = 0.013) but the correlation was attenuated when controlling for birth length (P = 0.089).

CONCLUSIONS

The hypothesis that a high content of glutamic acid and glutamine in breast milk could downregulate milk intake to a degree affecting early growth could not be confirmed. Maternal factors associated with the level of these FAA in milk and the potential effect on the infant should be investigated further.

Mother and Infant Body Mass Index, Breast Milk Leptin and Their Serum Leptin Values

Purpose: This study investigates correlations between mother and infant Body Mass Index (BMI), their serum leptin values and breast milk leptin concentration in early infancy. Subjects and Methods: We determined serum leptin values in 58 healthy infants and leptin values in their mothers’ breast milk, using radioimmunoassay (RIA). Infant and maternal anthropometrics were measured. Results: Median leptin concentration was 3.9 ng/mL (interquartile range (IQR): 2.75) in infant serum, 4.27 ng/mL (IQR: 5.62) in maternal serum and 0.89 ng/mL (IQR: 1.32) in breast milk. Median maternal BMI and weight were 24 kg/m² (IQR: 4.41) and 64 kg (IQR: 15). Median infant BMI was 15.80 kg/cm² (IQR: 4.02), while average weight was 5.130 kg (IQR: 1.627). Infants serum leptin values positively correlated with infants’ BMI (p = 0.001; r = 0.213) and breast milk leptin (p = 0.03; r = 0.285). Maternal serum leptin values positively correlated with maternal BMI (p = 0.000, r = 0.449) and breast milk leptin ones (p = 0.026; r = 0.322). Conclusion: Breast milk leptin and maternal BMI could influence infant serum leptin values. Further studies are needed to better elucidate the role of genetics and environment on infant leptin production and risk of obesity later in life.

A narrative review of the associations between six bioactive components in breast milk and infant adiposity

OBJECTIVE

This narrative review examines six important non-nutritive substances in breast milk, many of which were thought to have little to no biological significance. The overall objective is to provide background on key bioactive factors in breast milk believed to have an effect on infant outcomes (growth and body composition).

METHODS

The evidence for the effects of the following six bioactive compounds in breast milk on infant growth outcomes are reviewed: insulin, leptin, adiponectin, ghrelin, interleukin-6, and tumor necrosis factor-α.

RESULTS

The existing literature on the effects of breast milk insulin, ghrelin, interleukin-6, and tumor necrosis factor-α and their associations with infant growth and adiposity is sparse. Of the bioactive compounds reviewed, leptin and adiponectin are the most researched. Data reveal that breast milk adiponectin has negative associations with growth in infancy.

CONCLUSIONS

There is a need for innovative, well-designed studies to improve causal inference and advance our understanding in the effects of breast milk and its components on offspring growth and body composition. The recommendations provided, along with careful consideration of both known and unknown factors that affect breast milk composition, will help improve, standardize, and ultimately advance this emergent field.

A Case Report of a Breastfed Infant's Excessive Weight Gains over 14 Months

High infant weight gain is associated with subsequent overweight and obesity and so may contribute to related comorbidities such as metabolic syndrome and cardiovascular disease. The growth acceleration hypothesis proposes that early and rapid growth in infancy can shape the metabolic profile to increase susceptibility to obesity. Although breastfeeding reduces the infant's risk of subsequent overweight and obesity, high infant weight gains are observed in this population. We report the case of an infant with excessive weight gains that persisted throughout 6 months of exclusive breastfeeding. The mother chose to continue breastfeeding despite medical advice to wean, and high weight gains continued for a further 8 months of breastfeeding and complementary foods. This is the first reported case of an exclusively breastfed infant with excessive weight gains (> 97th percentile) with contemporaneous measures of 24-hour breast milk intake and doses and concentrations of protein, fat, and energy. We found a high breast milk protein dose, which is associated with increased weight gain and lean body mass but not necessarily adiposity. It is likely that other influences also contributed to the high infant weight gain. High infant weight gain is multifactorial, with evolving evidence for the role of adipokines and genetic markers. Advice to replace breast milk with formula affects the dose-dependent protection from noncommunicable diseases afforded by breast milk and may not be an effective strategy for reducing adiposity.

Adiponectin oligomers are similarly distributed in adequate-for-gestational-age obese children irrespective of feeding in their first year

BACKGROUND

Nutrition and growth in early postnatal life have a role in future diseases. Our aim was to investigate adiponectin oligomers in adequate-for-gestational-age obese children with respect to type and duration of feeding in the first year of life.

METHODS

Adiponectin oligomers and cardiometabolic risk factors were measured in 113 adequate-for-gestational-age obese children, divided into group A (prolonged breast feeding, >6 mo), group B (short breast feeding, 1-6 mo), and group C (formula feeding from birth).

RESULTS

All the parameters were similar among the groups. Adiponectin oligomers did not correlate with gestational age, months of breast feeding, and time of weaning. Total and high-molecular weight adiponectin were differently distributed across gender and pubertal stages (P < 0.02), being lower in males from the start of puberty. Prepregnancy BMI and at the end of the pregnancy were negatively associated (P < 0.04) with total and medium-molecular weight adiponectin in female and male offspring, respectively.

CONCLUSIONS

Adiponectin oligomers and metabolic characteristics are similarly distributed in adequate-for-gestational-age obese children, irrespective of the type and duration of the feeding in the first year of life. Gender and mother's BMI in pregnancy are contributors to adiponectin regulation. Further studies will explain whether breastfeeding protects against metabolic impairment later in life.

Breastfeeding status at age 3 months is associated with adiposity and cardiometabolic markers at age 4 years in Mexican children

BACKGROUND

The effect of breastfeeding (BF) on cardiometabolic risk factors is not well characterized.

OBJECTIVE

The objective was to assess the association of BF status at 3 mo and duration with adiposity and cardiometabolic markers at 4 y.

METHODS

We studied 727 children with prospectively collected BF information and anthropometric measurements at 4 y, of whom 524 provided a nonfasting blood sample. BF status at 3 mo was classified as exclusive or predominant (EBF-PreBF), partial (PaBF), or nonbreastfeeding (NBF). Total duration of any BF was classified as <3 mo, 3- 6 mo, >6 to 12 mo, and >12 mo. We modeled associations of BF with body mass index (BMI; in kg/m(2)), serum total cholesterol and low-density lipoprotein (LDL) cholesterol, triglycerides (TGs), and insulin at 4 y.

RESULTS

Children who were NBF or PaBF at 3 mo had higher BMI [0.46 (95% CI: 0.16, 0.76) and 0.31 (95% CI: 0.07, 0.54), respectively] than the EBF-PreBF group (P < 0.01). NBF children had higher total cholesterol (8.02 mg/dL; 95% CI: 1.39, 14.64; P = 0.02) than children who were EBF-PreBF. LDL cholesterol (5.04 mg/dL; 95% CI: -0.72, 10.81) and TGs (12% change; 95% CI: -0.01, 0.24) showed similar patterns. An inverse association between EBF-PreBF and insulin, mediated through abdominal circumference, was documented (P < 0.05). Children breastfed <3 mo had higher BMI (0.44; 95% CI: 0.11, 0.77) at 4 y than children breastfed for >12 mo.

CONCLUSION

EBF and PreBF at 3 mo were associated with lower adiposity and serum total cholesterol in children at 4 y. In addition, BF >12 mo was associated with lower adiposity. These data confirm the importance of exclusive BF and prolonged BF for later cardiometabolic health.

Maternal characteristics associated with milk leptin content in a sample of Filipino women and associations with infant weight for age

BACKGROUND

Human milk contains many metabolic hormones that may influence infant growth. Milk leptin is positively associated with maternal adiposity and inversely associated with infant growth. Most research has been conducted in populations with higher leptin levels; it is not well understood how milk leptin may vary in lean populations or the associations that reduced leptin may have with infant size for age. It is also largely unknown if associations between maternal body composition and milk leptin persist past 1 year of age.

OBJECTIVES

We investigated the association between maternal body composition and milk leptin content in a sample of lean Filipino women and the association between milk leptin content and infant size for age.

METHODS

Milk samples were collected at in-home visits from 113 mothers from Cebu, Philippines. Milk leptin content was measured using EIA techniques; anthropometric data, dietary recalls, and household information were also collected.

RESULTS

Mean ± standard deviation (SD) milk leptin in this sample was 300.7 ± 293.6 pg/mL, among the lowest previously reported. Mean ± SD maternal percentage body fat was 24.8% ± 3.5%. Mean ± SD infant age was 9.9 ± 7.0 months, and mean ± SD weight for age z-score was -0.98 ± 1.06. Maternal percentage body fat was a significant, positive predictor of milk leptin content. Milk leptin was a significant, inverse predictor of infant weight and body mass index z-scores in infants 1 year old or younger.

CONCLUSION

The association between maternal body composition, milk leptin, and infant growth persists in mothers with lean body composition. Milk leptin is not associated with growth in older infants.

[Adiponectin levels in breast milk of overweight/obese and normal weight mothers in the metropolitan area of Monterrey, México]

BACKGROUND

Given the current epidemic of childhood obesity, it has become increasingly important to understand the risks and protective factors associated with this disease. Breastfeeding has been identified as a protective factor; however, the mechanism responsible has not been elucidated. One of the current theories analyzes the role of hormones in breast milk, with special emphasis on adiponectin. This study aims to compare adiponectin levels in breast milk of mothers with normal weight with those in breast milk of overweight/obese mothers as well as to correlate these levels with the infant's weight gain.

METHODS

Forty samples of breast milk were analyzed for adiponectin levels using ELISA, 20 from mothers with normal weight and 20 from overweight/obese mothers.

RESULTS

Adiponectin levels were lower in breast milk obtained from overweight/obese mothers than in breast milk from mothers with normal weight (p <0.05). When comparing infant weight gain, those fed with breast milk containing higher concentrations of adiponectin had a lower weight gain than those fed with breast milk containing low levels of the hormone (p <0.05).

CONCLUSIONS

There is a strong negative correlation between mothers' BMI and adiponectin levels in breast milk. Mothers with a higher BMI had lower adiponectin levels in their breast milk. There is also a negative relationship between adiponectin levels in breast milk and weight gain of breastfed infants. Infants breast fed with adiponectin-rich breast milk had a lower weight gain.

Adipokines in breast milk: an update

Epidemiological surveys indicate that nutrition in infancy is implicated in the long-term tendency to obesity and that a longer duration of breastfeeding is associated with a protective effect against metabolic disorders later in life. However, the precise cause of this association is not well understood. Recent studies on the compounds present in human breast milk have identified various adipokines, including leptin, adiponectin, resistin, obestatin, nesfatin, ghrelin and apelins. Some of these compounds are involved in the regulation of food intake and energy balance. The presence of these adipokines in breast milk suggests that they may be responsible for the regulation of growth in early infancy and that they could influence the energy balance and development of metabolic disorders in childhood and adulthood.

The relationship between bioactive components in breast milk and bone mass in infants

Human breast milk (HBM) contains numerous bioactive components, recently shown to be associated with growth and body composition in breastfed offspring. Reciprocity in adipogenic and osteogenic pathways suggests bone mass may also be influenced by these components. The association between bioactive components found in HBM and bone mineral content (BMC), to our knowledge, is unknown. The purpose of this proof-of-principle study was to evaluate the association between specific bioactive components in HBM in exclusively breastfed infants and skeletal health in the first 6 months of life and examine potential gender differences in these associations. Thirty-five mother-infant dyads were followed from 1 to 6 months. The contents of a single breast expression were used for analyses of bioactive components (insulin, glucose, leptin, interleukin-6 and tumor necrosis factor-α (TNFα), whereas BMC was evaluated by dual-energy X-ray absorptiometry. In the total sample, there was a positive association between TNFα and BMC at 1 (P=0.004) and 6 months (P=0.007). When stratified by sex, females exhibited a positive association between BMC and glucose and an inverse relationship between BMC and TNF-α at 1 month with TNF-α strengthening (P=0.006) at 6 months. In males, at 6 months a positive relationship between BMC and HBM glucose and an inverse relationship with HBM leptin were observed with no associations observed at 1 month. Although preliminary, the associations between bioactive components in HBM highlight the importance HBM has on bone accretion. It is critically important to identify factors in HBM that contribute to optimal bone health.

Troubled sleep: Night waking, breastfeeding and parent-offspring conflict

Disrupted sleep is probably the most common complaint of parents with a new baby. Night waking increases in the second half of the first year of infant life and is more pronounced for breastfed infants. Sleep-related phenotypes of infants with Prader-Willi and Angelman syndromes suggest that imprinted genes of paternal origin promote greater wakefulness whereas imprinted genes of maternal origin favor more consolidated sleep. All these observations are consistent with a hypothesis that waking at night to suckle is an adaptation of infants to extend their mothers’ lactational amenorrhea, thus delaying the birth of a younger sib and enhancing infant survival.

Influence of prolonged storage process, pasteurization, and heat treatment on biologically-active human milk proteins

OBJECTIVES

The bioactive proteins in human milk may be influenced by prolonged storage process, pasteurization, and heat treatment. This study was conducted to evaluate the effects of these procedures.

MATERIALS AND METHODS

Three forms of human milk - freshly expressed, frozen at -20°C for a prolonged duration, and pasteurized milk - were collected from 14 healthy lactating mothers and a milk bank. The concentrations of major bioactive proteins (secretory immunoglobulin A, lactoferrin, lysozyme, and leptin) were quantified using enzyme-linked immunosorbent assay kits. Changes in these proteins by heat treatment at 40°C or 60°C for 30 minutes were further evaluated.

RESULTS

The mean concentrations of lactoferrin and secretory immunoglobulin A were significantly reduced by 66% and 25.9%, respectively, in pasteurized milk compared with those in freshly-expressed milk. Heat treatment at 40°C or 60°C did not cause significant changes in lactoferrin and secretory immunoglobulin A, but there was an apparent increase in lysozyme (p = 0.016). There were no significant differences in leptin level among these three forms of milk prior to (p = 0.153) or after heat treatment (p = 0.053).

CONCLUSION

Various freezing/heating/pasteurization processes applied to human milk prior to delivery to neonates could affect the concentration of immunomodulatory proteins, especially lactoferrin, secretory immunoglobulin A, and lysozyme. Leptin was unaffected by the various handling processes tested. Fresh milk was found to be the best food for neonates. Further studies are warranted to evaluate the functional activity of these proteins and their effects on infants' immunological status.

High serum leptin levels in infancy can potentially predict obesity in childhood, especially in formula-fed infants

AIM

To investigate serum leptin levels in breast-fed and formula-fed infants in infancy and their possible relationship to body mass index (BMI) in childhood.

METHODS

We enrolled 237 healthy term infants between September 2000 and April 2004 and tested their serum leptin levels, took anthropometric measurements and calculated BMI. A follow-up study was carried out to evaluate the BMI of 89 of these infants in childhood, in relation to their serum leptin levels in infancy, at a median (interquartile range) age of 8.8 years (7.8-10.2). The statistical significance of this multivariate analysis was set at p < 0.05.

RESULTS

Breast-fed infants had significantly higher serum leptin levels than formula-fed ones (p < 0.05). Children who were formula-fed in infancy had a significantly higher BMI, at follow-up, than those who were breast-fed (p < 0.001). Furthermore, we identified a leptin cut-off value of 2.7 ng/mL, below which infants had a higher BMI in childhood.

CONCLUSION

A higher leptin level in infancy may be inversely associated with BMI in childhood, suggesting that this hormone in infancy is a potential predictor of obesity in later life. Further investigation is required to be conclusive and to confirm our empirical evidence.

Relationship between Breast Feeding and Obesity in Children with Low Birth Weight

Background

Breast feeding appears to play a role in determining obesity and abdominal obesity during childhood, specifically in children with a history of low birth weight.

Objective

The purpose of this study is to investigate the relation of breast-feeding with either of abdominal obesity and obesity among Iranian school children.

Materials and Methods

A total of 1184 students (625 girls and 559 boys), aged 10 to 13 years old, were selected from 112 governmental elementary schools in Iran. Height, weight, waist circumference and blood pressure were measured using standard instruments and a pretested standardized questionnaire was performed for compiling information about family economics and educational level, first–degree family history of obesity, history of breast feeding, food pattern and birth weight, as well.

Results

13.68% (n = 160) of students had a history of low birth weight, and 26.41% of them had abdominal obesity. Of all participants, 22.04% were overweight and 5.32% were obese which was more prevalent in girls than in boys (P = 0.03). First-degree family history of obesity (P = 0.001), excessive gestational weight gain (P = 0.001) and birth weight (P = 0.01) were significantly correlated with the prevalence of obesity and abdominal obesity during childhood. Moreover the prevalence of abdominal obesity in children with low birth weight was significantly correlated with breast feeding (P = 0.04); But this relation was not significantly about obesity in our participants (P = 0.9). Furthermore duration of breast feeding was significantly and inversely correlated with obesity and abdominal obesity in schoolchildren with low birth weight (P = 0.01).

Conclusions

The results suggest that Breast feeding and its long-term consequences were important factors for preventing metabolic syndrome criteria in childhood and later years of life span. With regard to the increasing prevalence of obesity in children, more research is urgently needed to clarify whether breast feeding have negative consequences for the risk of chronic disease in children, especially in children with low birth weight.

Feeding choice has a gender-associated effect on infant growth

BACKGROUND

Appropriate nutrition during childhood is important for preventing future development of lifestyle-related diseases. The effect of feeding choice on infant growth in Japan is not known.

METHODS

Data from 204 healthy schoolchildren (age, 6-9 years) were obtained retrospectively from their parents by questionnaires. Breast-fed (BF) and formula-fed (FF) groups were defined as those fed only breast milk or formula milk at 4 months of age, respectively. There were 71 children (M/F, 31/40) in BF and 30 (M/F, 19/11) in FF. Anthropometric data at birth, and at 1, 4, 7, 10, 18, and 36 months of age in male and female infants were compared between the groups.

RESULTS

In male infants, height was significantly lower at 4 months, bodyweight was lower from 4 to 18 months, and body mass index (BMI) was lower from 10 to 36 months in BF than in FF. The standard deviation scores (SDS) for height, weight and BMI had a similar pattern. No significant differences were observed for these variables for female infants in BF compared with FF. Multiple regression analysis showed that birthweight, mother's pre-pregnancy weight, and infant feeding choice were significant factors associated with weight-SDS at 18 and 36 months. Feeding choice was the only factor associated with BMI-SDS at 18 months.

CONCLUSIONS

Infant feeding choice had a gender-associated effect on growth during infancy. When evaluating infant growth, not only birthweight and mother's pre-pregnancy weight, but also infant feeding choice and gender should be considered.

Presence and dynamics of leptin, GLP-1, and PYY in human breast milk at early postpartum

OBJECTIVE

The presence of appetite hormones, namely glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and leptin in breast milk may be important in infant feeding regulation and infant growth. This study evaluated whether concentrations of GLP-1, PYY, and leptin change across a single feeding (from fore- to hindmilk), and are associated with maternal and infant anthropometrics.

DESIGN AND METHODS

Thirteen postpartum women (mean ± SD: 25.6 ± 4.5 years, 72.0 ± 11.9 kg) provided fore- and hindmilk samples 4-5 weeks after delivery and underwent measurements of body weight and composition by Dual X-ray Absorptiometry. GLP-1, PYY, and leptin concentrations were measured using radioimmunoassay, and milk fat content was determined by creamatocrit.

RESULTS

Concentration of GLP-1 and content of milk fat was higher in hindmilk than foremilk (P ≤ 0.05). PYY and leptin concentrations did not change between fore- and hindmilk. Both leptin concentration and milk fat content were correlated with indices of maternal adiposity, including body mass index (r = 0.65-0.85, P < 0.02), and fat mass (r = 0.65-0.84, P < 0.02). Hindmilk GLP-1 was correlated with infant weight gain from birth to 6 months (r = -0.67, P = 0.034).

CONCLUSION

The presence of appetite hormones in breast milk may be important in infant appetite and growth regulation.

Cortisol regulation in 12-month-old human infants: associations with the infants' early history of breastfeeding and co-sleeping

Experiences during early life are suggested to affect the physiological systems underlying stress responses, including the hypothalamic-pituitary-adrenal axis (HPA axis). While stressful early experiences have been associated with dysregulated HPA-axis functioning, positive early experiences, i.e. high maternal caregiving quality, contribute to more optimal HPA-axis functioning. Influences of other early caregiving factors, however, are less well documented. The goal of this study was to examine whether breastfeeding and co-sleeping during the first 6 months of life were associated with infant cortisol regulation, i.e. cortisol reactivity and recovery, to a stressor at 12 months of age. Participants were 193 infants and their mothers. Information on breastfeeding and co-sleeping was collected using weekly and daily sleep diaries, respectively, for the first 6 months of life. Co-sleeping was defined as sleeping in the parents' bed or sleeping in the parents' room. At 12 months of age, infants were subjected to a psychological stressor [Strange Situation Procedure (SSP); Ainsworth et al. 1978]. Salivary cortisol was measured prestressor and at 25, 40, and 60 min poststressor to measure reactivity and recovery. Regression analyses showed that after controlling for maternal sensitivity, infant attachment status, feeding, and sleeping arrangements at 12 months of age and other confounders, more weeks of co-sleeping predicted lower infant cortisol reactivity to the SSP. Also, more weeks of breastfeeding predicted quicker cortisol recovery. These results indicate that an early history of co-sleeping and breastfeeding contributes positively to cortisol regulation in 12-month-olds.