Longitudinal effects of prenatal exposure to plastic-derived chemicals and their metabolites on asthma and lung function from childhood into adulthood.

BACKGROUND AND OBJECTIVE: Environmental exposure to phthalates and bisphenol A (BPA), chemicals used in the production of plastics, may increase risk for asthma and allergies. However, little is known about the long-term effects of early life exposure to these compounds. We investigated if prenatal exposure to these compounds was associated with asthma, allergy and lung function outcomes from early childhood into adulthood in a cohort study. METHODS: Maternal serum samples collected from 846 pregnant women in the Raine Study were assayed for BPA and phthalate metabolites. The children of these women were followed up at 5, 13 and 22 years where spirometry and respiratory questionnaires were conducted to determine asthma and allergy status. Lung function trajectories were derived from longitudinal spirometry measurements. Multinomial logistic regression and weighted quantile sum regression was used to test associations of individual and chemical mixtures with asthma phenotypes and lung function trajectories. RESULTS: Effects of prenatal BPA and phthalates on asthma phenotypes were seen in male offspring, where BPA was associated with increased risk for persistent asthma, while mono-iso-butyl phthalate and mono-iso-decyl phthalate was associated with increased risk for adult asthma. Prenatal BPA had no effect on lung function trajectories, but prenatal phthalate exposure was associated with improved lung function. CONCLUSION: Prenatal BPA exposure was associated with increased likelihood of persistent asthma in males, while prenatal phthalate exposure was associated with increased likelihood of adult asthma in males. Results suggest that prenatal exposure to prenatal BPA and phthalates affect asthma risk, particularly in males, however lung function was not adversely affected.

Robotic automation of a UHPLC/MS-MS method profiling one-carbon metabolites, amino acids, and precursors in plasma.

Amino acids (AAs) and one-carbon (1-C) metabolism compounds are involved in a range of key metabolic pathways, and mediate numerous health and disease processes in the human body. Previous assays have quantified a limited selection of these compounds and typically require extensive manual handling. Here, we describe the robotic automation of an analytical method for the simultaneous quantification of 37 1-C metabolites, amino acids, and precursors using reversed-phase ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry (UHPLC/MS-MS). Compound extraction from human plasma was tested manually before being robotically automated. The final automated analytical panel was validated on human plasma samples. Our automated and multiplexed method holds promise for application to large cohort studies.

The impact of antenatal Bisphenol A exposure on male reproductive function at 20-22 years of age.

Bisphenol A (BPA) is a ubiquitous chemical suspected to possess oestrogenic hormonal activities. Male population studies suggest a negative impact on testicular function. As Sertoli cell proliferation occurs during fetal or early postnatal life, it is speculated that oestrogenic environmental exposures may influence mature testicular function. Among 705 Western Australian Pregnancy Cohort (Raine) Study men aged 20-22 years, 404 underwent testicular ultrasound examination (149 had maternal serum available), and/or 365 provided semen (136 had maternal serum) and/or 609 serum samples for sex steroids, gonadotrophins and inhibin B analysis (244 had maternal serum). Maternal serum collected at 18 and 34 weeks' gestation was pooled and assayed for concentrations of total BPA (free plus conjugated) as an estimate of antenatal exposure. Testicular volume was calculated by ultrasonography, and semen analysis performed. Serum LH, FSH and inhibin B were measured by immunoassay; testosterone, oestradiol, oestrone andBPA were measured by liquid chromatography-mass spectrometry. BPA levels were detectable in most (89%) maternal serum samples. After adjustment for maternal smoking, abstinence and varicocele, sperm concentration and motility were significantly correlated to maternal serum BPA (r = 0.18; P = 0.04 for both). No other associations of maternal serum BPA with testicular function were observed.

Variation of Human Milk Glucocorticoids over 24 hour Period.

Human milk (HM) contains a complex array of hormones, including members of the glucocorticoid family. The predominant glucocorticoids, cortisol and cortisone may influence the growth and behaviour of the breastfed infant. However, little is understood of the factors regulating the levels of these hormones within HM. The aim of the study was to examine HM cortisol and cortisone concentration, measured in samples collected at each feed during a 24 hour period. Twenty three exclusively breastfeeding mothers collected milk, prior to and after each breastfeeding session over 24 hour period at 3.2(1.60) months. HM cortisol and cortisone levels were measured using high pressure liquid chromatography mass spectroscopy. Cortisone was the predominant glucocorticoid (3.40 ng/ml), and cortisol was detected in all samples (1.62 ng/ml). A positive correlation was found between cortisone and cortisol (r = 0.61, y = 1.93 ± 0.24, p < 0.0001). Cortisol and cortisone concentrations were significantly higher in feeds in the morning (2.97 ng/ml and 4.88 ng/ml), compared to afternoon (1.20 ng/ml and 3.54 ng/ml), evening (0.69 ng/ml and 2.13 ng/ml) and night (1.59 and 3.27 ng/ml). No difference was found between glucocorticoids level of the milk expressed for collection either before or immediately after the breastfeed, or between milk collected from the left or right breast. This study shows that HM glucocorticoid concentrations exhibit a 24 hour pattern, with highest peak levels in the early morning, reflecting the circadian pattern as previously reported in plasma. Thus, HM glucocorticoid concentrations are likely to reflect those in the maternal circulation.

The relationship between 25-hydroxyvitamin D concentration in early pregnancy and pregnancy outcomes in a large, prospective cohort.

Vitamin D insufficiency and deficiency have been associated with an increased risk of adverse pregnancy outcomes. Controversy remains as findings have been inconsistent between disparate populations. The aim of this study was to investigate the relationship between vitamin D status and pregnancy outcomes in a large, prospective pregnancy cohort. 25-Hydroxyvitamin D concentration was analysed in serum samples collected at 15 weeks of gestation from 1710 New Zealand women participating in a large, observational study. Associations between vitamin D status and pre-eclampsia, preterm birth, small for gestational age (SGA) and gestational diabetes were investigated. The mean 25-hydroxyvitamin D concentration was 72·9 nmol/l. In all, 23 % had 25-hydroxyvitamin D concentrations 75 nmol/l (OR 2·3; 95 % CI 1·1, 5·1). However, this effect was not significant when adjustments were made for BMI and ethnicity (OR 1·8; 95 % CI 0·8, 4·2). 25-Hydroxyvitamin D concentration at 15 weeks was not associated with development of pre-eclampsia, spontaneous preterm birth or SGA infants. Pregnancy complications were low in this largely vitamin D-replete population.

Effect of maternal periconceptional undernutrition in sheep on cortisol regulation in offspring from mid-late gestation, through to adulthood.

Introduction: Maternal periconceptional undernutrition (PCUN) alters fetal hypothalamic-pituitary-adrenal axis (HPAA) function and placental glucocorticoid metabolism in sheep. The effects of PCUN on HPAA function in adult life are not known. We investigated the effects of PCUN on fetal adrenal development across gestation and on cortisol regulation in adult offspring. Methods: Ewes were undernourished from 61 days before to 30 days after conception ('PCUN') or fed ad libitum ('N'). mRNA expression in the fetal adrenal gland of ACTH receptor (ACTHR), steroidogenic acute regulatory protein (STAR), cytochrome P450 17A1 (CYP17A1), 11beta-hydroxysteroid-dehydrogenase type 2 (11ßHSD2), insulin-like growth factor-2 (IGF2), and in the fetal hippocampus of 11ßHSD1, 11ßHSD2, mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) was determined at 50 (adrenal only), 85, 120 and 131 days of gestation (term=148 days). In adult offspring (≥ 3 years, N; 10 female, 5 male, PCUN; 10 female, 10 male) a combined arginine vasopressin (AVP, 0.1 µg/kg) and corticotropin-releasing hormone (CRH, 0.5 µg/kg) challenge and a metyrapone (40 mg/kg) challenge were undertaken. mRNA expression of ACTHR, STAR and CYP17A1 were determined in adult adrenals. Results: Fetal adrenal STAR, CYP17A1 and IGF2 mRNA expression were not different between groups in early gestation but were higher in PCUN than N at 131 days' gestation (all p<0.01). PCUN reduced fetal hippocampal MR and GR mRNA expression by 50% at 85 day, but not in later gestation. Adult offspring plasma cortisol responses to AVP+CRH or metyrapone were not different between groups. Plasma ACTH response to AVP+CRH was lower in PCUN males but ACTH response to metyrapone was not different between groups. Adult adrenal ACTHR, STAR, and CYP17A1 mRNA expression were not affected by PCUN. Conclusions: We conclude that the effects of PCUN on fetal HPAA function that became apparent in late gestation, are not reflected in adrenal cortisol secretion in mid-adulthood.

Effects of periconceptional undernutrition on maternal taurine concentrations in sheep.

Taurine has an important role in numerous physiological processes, including many aspects of fetal development such as development of the pancreas and brain, and requirements increase during pregnancy. Periconceptional undernutrition has long-term effects on pancreas and brain function of the offspring, but the effects on maternal taurine economy are unknown. We, therefore, studied the effects of different periods of periconceptional undernutrition on maternal plasma and urine taurine concentrations before and during pregnancy. Four groups of singleton-bearing ewes were studied (n 10-11): controls fed ad libitum, and groups undernourished from 60 d before until mating (PreC), from 2 d before mating until 30 d after mating (PostC) or from 60 d before until 30 d after mating (Pre+PostC). In PreC ewes, plasma taurine concentrations remained at control levels for the first 30 d, and then decreased through the remainder of undernutrition, but recovered by 30 d after mating; urinary taurine excretion was low at mating, but recovered similarly. In PostC ewes, plasma taurine concentrations recovered after 2 weeks despite ongoing undernutrition; urinary taurine excretion had recovered by 30 d after mating. Pre+PostC ewes followed the same pattern as PreC for the first 60 d, but plasma taurine concentrations and urinary excretion recovered slowly, and did not reach the control levels until 97 d. These data suggest that different periods of mild periconceptional undernutrition in sheep have different but substantial effects on maternal taurine homoeostasis. These effects may be one mechanism by which maternal periconceptional undernutrition alters development of the offspring with implications for adult health.

Effects of maternal periconceptional undernutrition in sheep on offspring glucose-insulin axis function into adulthood.

Maternal periconceptional undernutrition (PCUN) affected fetal pancreatic maturation in late gestation lambs and impaired glucose tolerance in 10-month-old sheep. To examine the importance of the timing of maternal undernutrition around conception, a further cohort was born to PCUN ewes [undernourished for 61 d before conception (PreC), 30 d after conception (PostC), or 61 d before until 30 d after conception (PrePostC)], or normally fed ewes (Control) (n = 15-20/group). We compared glucose tolerance, insulin secretion, and sensitivity at 36 months of age. We also examined protein expression of insulin signalling proteins in muscle from these animals and in muscle from a fetal cohort (132 d of gestation; n = 7-10/group). Adult PostC and PrePostC sheep had higher glucose area under the curve than Controls (P = 0.07 and P = 0.02, respectively), whereas PreC sheep were similar to Controls (P = 0.97). PostC and PrePostC had reduced first-phase insulin secretion compared with Control (P = 0.03 and P = 0.02, respectively). PreC was similar to Control (P = 0.12). Skeletal muscle SLC2A4 protein expression in PostC and PrePostC was increased 19%-58% in fetuses (P = 0.004), but decreased 39%-43% in adult sheep (P = 0.003) compared with Controls. Consistent with this, protein kinase C zeta (PKCζ) protein expression tended to be increased in fetal (P = 0.09) and reduced in adult (P = 0.07) offspring of all PCUN ewes compared with Controls. Maternal PCUN alters several aspects of offspring glucose homeostasis into adulthood. These findings suggest that maternal periconceptional nutrition has a lasting impact on metabolic homeostasis of the offspring.

Population epidemiology and concordance for plasma amino acids and precursors in 11-12-year-old children and their parents.

Amino acid (AA) concentrations are influenced by both exogenous (e.g. diet, lifestyle) and endogenous factors (e.g. genetic, transcriptomic, epigenetic, and metabolomic). Fasting plasma AA profiles in adulthood are predictive of diabetes risk over periods of up to 12 years. Data on AA profiles in cross-generational cohorts, including individuals from shared gene-environment settings are scarce, but would allow the identification of the contribution of heritable and environmental factors characterising the levels of circulating AAs. This study aimed to investigate parent-child (familial dyad) concordance, absolute differences between generations- (children versus adults), age- (in adults: 28-71 years), and sex-dependent differences in plasma AA concentrations. Plasma AA concentrations were measured by UHPLC/MS-MS in 1166 children [mean (SD) age 11 (0.5) years, 51% female] and 1324 of their parents [44 (5.1) years, 87% female]. AA concentrations were variably concordant between parents and their children (5-41% of variability explained). Most AA concentrations were higher in adults than children, except for the non-essential AAs arginine, aspartic acid, glutamine, hydroxy-proline, proline, and serine. Male adults and children typically had higher AA concentrations than females. The exceptions were alanine, glutamine, glycine, hydroxy-proline, serine, and threonine in girls; and glycine and serine in women. Age, sex, and shared familial factors are important determinants of plasma AA concentrations.

Trimethylamine N-oxide (TMAO) Is not Associated with Cardiometabolic Phenotypes and Inflammatory Markers in Children and Adults.

BACKGROUND: Trimethylamine N-oxide (TMAO) is a diet- and microbiome-derived metabolite and a proposed biomarker of adverse cardiometabolic outcomes. TMAO studies have mainly been conducted in individuals with cardiometabolic disease, and studies in population-derived samples are limited. OBJECTIVE: We aimed to investigate the associations between plasma TMAO concentrations and its precursors [carnitine, choline, betaine, and dimethylglycine (DMG)] with metabolic syndrome (MetS) scores, preclinical cardiovascular phenotypes, and inflammatory biomarkers (i.e. high-sensitivity C-reactive protein and serum glycoprotein acetyls) in a population-derived cohort of children and their parents. METHODS: The concentrations of TMAO and its precursors were quantified using UHPLC coupled with tandem MS (UHPLC/MS-MS) in 1166 children (mean age 11 y ± 0.5 y, 51% female) and 1324 adults (44 y ± 5.1 y, 87% female) participating in The Growing Up in Australia's Child Health CheckPoint Study. We developed multivariable fractional polynomial models to analyze associations between TMAO, its precursors, MetS (adjusted for sex and age), and cardiovascular phenotypes (adjusted for sex, age, BMI, household income, and the urinary albumin to creatinine ratio). Pearson's correlations were computed to identify associations between TMAO, its precursors, and inflammatory biomarkers. RESULTS: The concentrations of TMAO precursors, but not TMAO itself, were associated with MetS, cardiovascular phenotypes, and inflammatory biomarkers in children and adults. CONCLUSIONS: TMAO precursors, but not TMAO itself, were associated with adverse cardiometabolic and inflammatory phenotypes in children and adults. TMAO precursor concentrations may better reflect cardiovascular health and inflammatory status within the wider population. Replication in other population settings and mechanistic studies are warranted.

Transfer of bisphenol A across the human placenta.

OBJECTIVE: The objective of the investigation was to study placental transfer and conjugation of bisphenol A (BPA) across the human placenta. STUDY DESIGN: Human placentae obtained from healthy term singleton pregnancies were utilized in a dual recirculating model of ex vivo placental perfusion. Seven placentae were perfused with BPA (10 ng/mL) added to the maternal perfusate for 180 minutes. Antipyrine and fluorescein isothiocyanate dextran were used as positive and negative controls, respectively, to validate integrity of the circuits. Concentrations of BPA and its conjugates were determined by liquid chromatography-mass spectrometry. RESULTS: The transfer percentage for antipyrine and BPA were 25.5 +/- 1.13% and 27.0 +/- 1.88%, respectively, and the transfer index for BPA was 1.1 +/- 0.09 after 180 minutes of perfusion. Only 3.2 +/- 1.6% of BPA in the fetal compartment was in the conjugated form. CONCLUSION: Bisphenol A at low environmentally relevant levels can transfer across the human placenta, mainly in active unconjugated form.

Cortisol urinary metabolites in dogs with hypercortisolism, congestive heart failure, and healthy dogs: pilot investigation.

Nonadrenal diseases (NAD), including congestive heart failure (CHF), can affect the conversion of cortisone to cortisol favoring the production of cortisol's urinary downstream metabolites 5α/5ß-tetrahydrocortisol (THF) relative to tetrahydrocortisone (THE). We hypothesized that healthy dogs would have lower urinary levels of cortisol, cortisone, THF, and THE than dogs with hypercortisolism (HC) or CHF, and the latter would have higher urinary levels of THF and lower THE than dogs with HC. Four, 9, and 8 dogs with HC, CHF, and normal health, respectively, were included in a pilot prospective cross-sectional study. A single morning voided urine sample was analyzed for urinary cortisol metabolites by liquid chromatography-mass spectrometry. The percentages of conjugated urinary metabolites were significantly higher in dogs with CHF than in healthy dogs (p = 0.001), and not different in HC dogs (p = 0.07). Log-transformed urine cortisol metabolites-to-creatinine ratios in healthy dogs were significantly lower than the 2 other groups (p < 0.001). The urinary free THE:THF ratio was significantly higher (p < 0.001) than the urinary total and conjugated THE:THF ratios. Health status did not affect the total, conjugated, and free THE:THF ratios (p = 0.61). Additional studies are needed to investigate differences in cortisol metabolites between dogs with HC and NAD to accurately discriminate between the groups.

Human Milk Glucocorticoid Levels Are Associated With Infant Adiposity and Head Circumference Over the First Year of Life.

Human milk (HM) is a complex and dynamic biological fluid, which contains appreciable concentrations of the glucocorticoids, cortisol and cortisone. Experimental studies in non-human primates suggest the HM glucocorticoids' impact on infant growth and body composition. In this current study, analysis is made of the relationships between HM glucocorticoid concentrations and the infant growth and development over the first year of life. HM was collected by lactating healthy women (n = 18), using a standardized protocol, at 2, 5, 9, and 12 months after childbirth. Cortisol and cortisone concentrations in the HM were measured using liquid chromatography mass spectrometry. Infant weight, length and head circumference were measured by standard protocols and percentage fat mass (% FM) determined by whole body bioimpedance. Cortisol and cortisone concentrations were unaltered over the analyzed lactation period (2-12 months), and were altered by infant sex. Although, HM cortisol was positively associated with infant percentage fat mass (% FM) (p = 0.008) and cortisone positively associated with infant head circumference (p = 0.01). For the first 12 months of life, the concentration of HM glucocorticoids levels was positively associated with infant adiposity (%FM) and head circumference. This preliminary evidence provides insight to a possible relationship between ingested HM glucocorticoids and infant body composition. Further studies are required to determine the mechanisms regulating HM glucocorticoids.

Circulatory and Urinary B-Vitamin Responses to Multivitamin Supplement Ingestion Differ between Older and Younger Adults.

Multivitamin and mineral (MVM) supplements are frequently used amongst older populations to improve adequacy of micronutrients, including B-vitamins, but evidence for improved health outcomes are limited and deficiencies remain prevalent. Although this may indicate poor efficacy of supplements, this could also suggest the possibility for altered B-vitamin bioavailability and metabolism in older people. This open-label, single-arm acute parallel study, conducted at the Liggins Institute Clinical Research Unit in Auckland, compared circulatory and urinary B-vitamer responses to MVM supplementation in older (70.1 ± 2.7 y, n = 10 male, n = 10 female) compared to younger (24.2 ± 2.8 y, n = 10 male, n = 10 female) participants for 4 h after the ingestion of a single dose of a commercial MVM supplement and standardized breakfast. Older adults had a lower area under the curve (AUC) of postprandial plasma pyridoxine (p = 0.02) and pyridoxal-5'phosphate (p = 0.03) forms of vitamin B6 but greater 4-pyridoxic acid AUC (p = 0.009). Urinary pyridoxine and pyridoxal excretion were higher in younger females than in older females (time × age × sex interaction, p < 0.05). Older adults had a greater AUC increase in plasma thiamine (p = 0.01), riboflavin (p = 0.009), and pantothenic acid (p = 0.027). In older adults, there was decreased plasma responsiveness of the ingested (pyridoxine) and active (pyridoxal-5'phosphate) forms of vitamin B6, which indicated a previously undescribed alteration in either absorption or subsequent metabolic interconversion. While these findings cannot determine whether acute B6 responsiveness is adequate, this difference may have potential implications for B6 function in older adults. Although this may imply higher B vitamin substrate requirements for older people, further work is required to understand the implications of postprandial differences in availability.

Plasma Trimethylamine N-Oxide and Its Precursors: Population Epidemiology, Parent-Child Concordance, and Associations with Reported Dietary Intake in 11- to 12-Year-Old Children and Their Parents.

BACKGROUND: Trimethylamine N-oxide (TMAO) is a microbiome- and diet-derived metabolite implicated in adverse cardiovascular outcomes. To date, studies of plasma TMAO concentrations have largely focused on individuals with metabolic disease. As such, data on TMAO concentrations in population settings and parent-child dyads are lacking. OBJECTIVES: This study aimed to investigate parent-child concordance, age, and sex effects on plasma concentrations of TMAO and its precursors [l-carnitine, choline, betaine, and dimethylglycine (DMG)]. Associations between concentrations of TMAO and its precursors and self-reported dietary intakes of animal protein (i.e., red meat, meat products, chicken, fish, milk products, and cheese) and fast-food meals were also investigated. METHODS: A total of 1166 children (mean ± SD age: 11 ± 0.5 y, 51% female) and 1324 parents (mean ± SD age: 44 ± 5.1 y, 87% female) had a biomedical assessment as part of Growing Up in Australia's Child Health Checkpoint. Plasma TMAO and precursor concentrations were quantified using ultra-high-pressure LC coupled with tandem MS. RESULTS: Familial dyads significantly contributed to plasma TMAO and precursor concentrations (P < 0.0001), explaining 37% of variance for TMAO concentrations. Least-square mean ± SE plasma TMAO was lower in children (0.79 ± 0.02 µM on the log-scale) than in adults (1.22 ± 0.02 µM). By contrast, children's betaine (40.30 ± 0.34 µM) and DMG concentrations (1.02 ± 0.01 µM on the log-scale) were higher than adults' betaine (37.50 ± 0.32 µM) and DMG concentrations (0.80 ± 0.01 µM) (P < 0.0001). Mean values of all metabolites, except adult TMAO, were higher in males than in females (P < 0.001). Greater reported intake of red meat and fish was associated with higher TMAO concentrations in both children [estimates (95% CIs) for red meat: 0.06 (0.01, 0.10); fish: 0.11 (0.06, 0.17)] and adults [red meat: 0.13 (0.08, 0.17); meat products: 0.07 (0.03, 0.12); and fish: 0.09 (0.04, 0.14)]. CONCLUSIONS: Age, sex, and shared family factors, including diet, contribute to variation in plasma concentrations of TMAO and its precursors.

Differences in Compositions of Gut Bacterial Populations and Bacteriophages in 5-11 Year-Olds Born Preterm Compared to Full Term.

Preterm infants are exposed to major perinatal, post-natal, and early infancy events that could impact on the gut microbiome. These events include infection, steroid and antibiotic exposure, parenteral nutrition, necrotizing enterocolitis, and stress. Studies have shown that there are differences in the gut microbiome during the early months of life in preterm infants. We hypothesized that differences in the gut microbial composition and metabolites in children born very preterm persist into mid-childhood. Participants were healthy prepubertal children aged 5-11 years who were born very preterm (≤32 weeks of gestation; n = 51) or at term (37-41 weeks; n = 50). We recorded the gestational age, birth weight, mode of feeding, mode of birth, age, sex, and the current height and weight of our cohort. We performed a multi'omics [i.e., 16S rRNA amplicon and shotgun metagenomic sequencing, SPME-GCMS (solid-phase microextraction followed by gas chromatography-mass spectrometry)] analysis to investigate the structure and function of the fecal microbiome (as a proxy of the gut microbiota) in our cross-sectional cohort. Children born very preterm were younger (7.8 vs. 8.3 years; p = 0.034), shorter [height-standard deviation score (SDS) 0.31 vs. 0.92; p = 0.0006) and leaner [BMI (body mass index) SDS -0.20 vs. 0.29; p < 0.0001] than the term group. Children born very preterm had higher fecal calprotectin levels, decreased fecal phage richness, lower plasma arginine, lower fecal branched-chain amino acids and higher fecal volatile (i.e., 3-methyl-butanoic acid, butyrolactone, butanoic acid and pentanoic acid) profiles. The bacterial microbiomes did not differ between preterm and term groups. We speculate that the observed very preterm-specific changes were established in early infancy and may impact on the capacity of the very preterm children to respond to environmental changes.

Comparison of the Acute Postprandial Circulating B-Vitamin and Vitamer Responses to Single Breakfast Meals in Young and Older Individuals: Preliminary Secondary Outcomes of a Randomized Controlled Trial.

B-vitamin deficiency is common in ageing populations either due to altered dietary habits or altered digestive and metabolic functions. There is limited data on the acute circulating concentrations of B-vitamins and their various forms (vitamers), following ingestion of realistic meals. This study compared the acute circulating B-vitamin and vitamer responses to either an energy-dense (ED) or a nutrient-dense (ND) breakfast meal, consumed in a randomized cross-over sequence, in older and younger adults (n = 15 and 15, aged 67.3 ± 1.5 and 22.7 ± 0.5 years (mean ± SEM), respectively). Eleven differing B-vitamins and vitamers were determined in plasma samples by ultra-high-performance liquid chromatography-tandem mass spectrometry, in the fasting and postprandial state (hourly for 5 h). While postprandial thiamine concentration increased following both meals, riboflavin increased only following a ND meal in both age groups. Many vitamins including nicotinic acid, pantothenic acid, pyridoxal, pyridoxamine, pyridoxal-5'phosphate, and 4-pyridoxic acid remained unaltered, and flavin mononucleotide (FMN), nicotinamide and nicotinuric acid concentrations reduced following both meals. Biological age and food composition had minimal impact on postprandial B-vitamin concentrations, yet the differences between the ED and ND meals for riboflavin highlight the importance of riboflavin intake to achieve adequacy.

Altered Dairy Protein Intake Does Not Alter Circulatory Branched Chain Amino Acids in Healthy Adults: A Randomized Controlled Trial.

Dairy, as a major component of a high protein diet, is a critical dietary source of branched chain amino acids (BCAA), which are biomarkers of health and diseases. While BCAA are known to be key stimulators of protein synthesis, elevated circulatory BCAA is an independent risk factor for type 2 diabetes mellitus. This study examined the impact of altered dairy intake on plasma BCAA and their potential relationship to insulin sensitivity. Healthy adults (n = 102) were randomized to receive dietary advice to reduce, maintain, or increase habitual dairy intake for 1 month. Food intake was recorded with food frequency questionnaires. Self-reported protein intake from dairy was reported to be reduced (-14.6 ± 3.0 g/day), maintained (-4.0 ± 2.0 g/day) or increased (+13.8 ± 4.1 g/day) according to group allocation. No significant alterations in circulating free amino acids (AA), including BCAA, were measured. Insulin sensitivity, as assessed by homeostatic model assessment-insulin resistance (HOMA-IR), was also unaltered. A significant change in dairy protein intake showed no significant effect on fasting circulatory BCAA and insulin sensitivity in healthy populations.

Impact of Preterm Birth on Glucocorticoid Variability in Human Milk.

BACKGROUND: Preterm birth is a stressful event for both the mother and infant. Whereas the initiation of breastfeeding is important for preterm infant health, little is known of the glucocorticoid hormones (cortisol and cortisone) in human milk following preterm birth. Research aim: The aim of this study was to investigate the relationship between human milk glucocorticoid concentrations and preterm birth. METHODS: Human milk was sampled weekly for up to 6 weeks from 22 women who delivered a preterm infant at 28 to 32 weeks' gestation. Human milk was analyzed for total and free cortisol and cortisone concentrations using liquid chromatography-tandem mass spectrometry. RESULTS: Milk sampled from mothers of preterm infants had more cortisone than cortisol ( p < .001), with a strong correlation between both hormones ( p = .001, r = .85). The cortisone was significantly higher in the milk of mothers who delivered infants after 30 weeks compared with those who delivered before 30 weeks of gestation ( p = .02). Glucocorticoid concentrations did not change over the sampling time (weeks 1 to 6 postpartum) and did not differ by infant gender. CONCLUSION: Glucocorticoids were present in all milk samples following preterm birth. Cortisone concentration tended to be higher in those who delivered after 30 weeks' gestation but did not increase further over the weeks following birth.

Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men.

The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring (13)C6 phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h(-1) in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h(-1) in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein.