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1.
Nutrients ; 12(2)2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32023931

RESUMO

Cooking changes the texture and tenderness of red meat, which may influence its digestibility, circulatory amino acids (AA) and gastrointestinal (GI) hormonal responses in consumers. In a randomised crossover intervention, healthy males (n = 12) consumed a beef steak sandwich, in which the beef was cooked by either a pan-fried (PF) or sous-vide (SV) method. Plasma AA were measured by ultrahigh performance liquid chromatography (UPLC), while plasma GI hormones were measured using a flow cytometric multiplex array. Following meat ingestion, the circulatory concentrations of some of the essential AA (all the branched-chain AA: leucine, isoleucine and valine; and threonine), some of the nonessential AA (glycine, alanine, tyrosine and proline) and some of the nonproteogenic AA (taurine, citrulline and ornithine) were increased from fasting levels by 120 or 180 min (p < 0.05). There were no differences in circulating AA concentrations between cooking methods. Likewise, of the measured GI hormones, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) concentrations increased from fasting levels after consumption of the steak sandwich (p < 0.05), with no differences between the cooking methods. In the healthy male adults, protein digestion and circulating GI hormone responses to a beef-steak breakfast were unaltered by the different cooking methods.

2.
Nutrients ; 12(1)2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31935821

RESUMO

While human milk composition is characterised by marked dynamicity, we are far from having a clear picture of what factors drive this variation. Hormones in human milk are known to vary according to specific maternal phenotypes, but limited evidence shows the infant also has a role in determining milk composition. The present study aimed to investigate the interplay between maternal and infant characteristics in relation to human milk hormonal profile. In total, 501 human milk samples from mothers recruited in the Finnish STEPS cohort study (Steps to the healthy development) were analysed. Pre-pregnancy and pregnancy maternal data, socioeconomic status and infant characteristics at birth were collated. Leptin, adiponectin, insulin-like growth factor-1 and cyclic Glycine-Proline in milk were measured. Multivariate analysis of variance (MANOVA) and linear regression were utilised for statistical analysis. Sex-specific interactions with maternal factors were observed, as the infant sex mediated associations between gestational diabetes and milk adiponectin (p = 0.031), birth-mode and total protein (p = 0.003), maternal education and insulin-like growth factor-1: cyclic Glycine-Proline ratio (p = 0.035). Our results suggest that changes in human milk composition are associated with interactions between maternal and infant characteristics and pathophysiological factors. Future work should expand on these findings and further explore the link between hormonal profiles in human milk and infant outcomes.

3.
Am J Clin Nutr ; 111(1): 149-160, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31773165

RESUMO

BACKGROUND: Lactose malabsorption (LM) is a major cause of digestive discomfort from dairy products. Recently, a role for bovine ß-casein A1 has been proposed. OBJECTIVES: We examined whether there are distinct symptoms of digestive discomfort due to either lactose or differing bovine ß-casein types. METHODS: Women (n = 40; age: 25.2 ± 0.5 y) with self-reported varying dairy tolerance underwent a 50-g lactose challenge. Based on postchallenge LM and digestive discomfort, participants were classified as either lactose intolerant (LI; n = 10, self-reported intolerant, diagnosed lactose intolerant), nonlactose dairy intolerant (NLDI; n = 20, self-reported intolerant, diagnosed lactose tolerant), or dairy tolerant (DT; n = 10, self-reported tolerant, diagnosed lactose tolerant). In a double-blinded randomized sequence, participants consumed 750 mL conventional milk (CON; containing A1 and A2 ß-casein and lactose), a2 Milk (A2M; exclusively containing A2 ß-casein with lactose), or lactose-free conventional milk (LF-CON; containing A1 and A2 ß-casein without lactose). Subjective digestive symptoms and breath hydrogen (measuring LM) were recorded regularly over 3 h, and further ad hoc digestive symptoms over 12 h. RESULTS: LI subjects experienced prolonged digestive discomfort with CON milk. A2M reduced (P < 0.05) some symptoms (nausea: A2M 8 ± 3 mm compared with CON 15 ± 3mm; fecal urgency: A2M 4 ± 1 compared with CON 10 ± 3 mm), and attenuated the rise in breath hydrogen over 3 h, relative to CON milk (A2M 59 ± 23 compared with CON 98 ± 25 ppm at 150 min; P < 0.01). In contrast, NLDI subjects experienced rapid-onset, transient symptoms (abdominal distension, bloating, and flatulence) without increased breath hydrogen, irrespective of milk type. CONCLUSIONS: In LI individuals, LM and digestive comfort with lactose-containing milks was improved with milk containing exclusively A2 ß-casein. Furthermore, self-reported dairy intolerance without LM (NLDI) is characterized by early-onset digestive discomfort following milk ingestion, irrespective of lactose content or ß-casein type. This trial was registered at www.anzctr.org.au as ACTRN12616001694404.

4.
Nutrients ; 11(12)2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31795162

RESUMO

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.

5.
Int J Sport Nutr Exerc Metab ; : 1-7, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31592623

RESUMO

PURPOSE: To determine the acute effects of carbohydrate (CHO) ingestion following a bout of maximal eccentric resistance exercise on key anabolic kinases of mammalian target of rapamycin and extracellular signal-regulated kinase (ERK) pathways. The authors' hypothesis was that the activation of anabolic signaling pathways known to be upregulated by resistance exercise would be further stimulated by the physiological hyperinsulinemia resulting from CHO supplementation. METHODS: Ten resistance-trained men were randomized in a crossover, double-blind, placebo (PLA)-controlled manner to ingest either a noncaloric PLA or 3 g/kg of CHO beverage throughout recovery from resistance exercise. Muscle biopsies were collected at rest, immediately after a single bout of intense lower body resistance exercise, and after 3 hr of recovery. RESULTS: CHO ingestion elevated plasma glucose and insulin concentrations throughout recovery compared with PLA ingestion. The ERK pathway (phosphorylation of ERK1/2 [Thr202/Tyr204], RSK [Ser380], and p70S6K [Thr421/Ser424]) was markedly activated immediately after resistance exercise, without any effect of CHO supplementation. The phosphorylation state of AKT (Thr308) was unchanged postexercise in the PLA trial and increased at 3 hr of recovery above resting with ingestion of CHO compared with PLA. Despite stimulating-marked phosphorylation of AKT, CHO ingestion did not enhance resistance exercise-induced phosphorylation of p70S6K (Thr389) and rpS6 (Ser235/236 and Ser240/244). CONCLUSION: CHO supplementation after resistance exercise and hyperinsulinemia does not influence the ERK pathway nor the mTORC1 target p70S6K and its downstream proteins, despite the increased AKT phosphorylation.

6.
Nutrients ; 11(9)2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31547446

RESUMO

Higher dietary protein intake is increasingly recommended for the elderly; however, high protein diets have also been linked to increased cardiovascular disease (CVD) risk. Trimethylamine-N-oxide (TMAO) is a bacterial metabolite derived from choline and carnitine abundant from animal protein-rich foods. TMAO may be a novel biomarker for heightened CVD risk. The purpose of this study was to assess the impact of a high protein diet on TMAO. Healthy men (74.2 ± 3.6 years, n = 29) were randomised to consume the recommended dietary allowance of protein (RDA: 0.8 g protein/kg bodyweight/day) or twice the RDA (2RDA) as part of a supplied diet for 10 weeks. Fasting blood samples were collected pre- and post-intervention for measurement of TMAO, blood lipids, glucose tolerance, insulin sensitivity, and inflammatory biomarkers. An oral glucose tolerance test was also performed. In comparison with RDA, the 2RDA diet increased circulatory TMAO (p = 0.002) but unexpectedly decreased renal excretion of TMAO (p = 0.003). LDL cholesterol was increased in 2RDA compared to RDA (p = 0.049), but no differences in other biomarkers of CVD risk and insulin sensitivity were evident between groups. In conclusion, circulatory TMAO is responsive to changes in dietary protein intake in older healthy males.

7.
Nutrients ; 11(7)2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31319625

RESUMO

Hydrogen (H2) measurement in exhaled breath is a reliable and non-invasive method to diagnose carbohydrate malabsorption. Currently, breath H2 measurement is typically limited to clinic-based equipment. A portable breath analyser (AIRE, FoodMarble Digestive Health Limited, Dublin, Ireland) is a personalised device marketed for the detection and self-management of food intolerances, including lactose malabsorption (LM). Currently, the validity of this device for breath H2 analysis is unknown. Individuals self-reporting dairy intolerance (six males and six females) undertook a lactose challenge and a further seven individuals (all females) underwent a milk challenge. Breath samples were collected prior to and at frequent intervals post-challenge for up to 5 h with analysis using both the AIRE and a calibrated breath hydrogen analyser (BreathTracker, QuinTron Instrument Company Inc., Milwaukee, WI, USA). A significant positive correlation (p < 0.001, r > 0.8) was demonstrated between AIRE and BreathTracker H2 values, after both lactose and milk challenges, although 26% of the AIRE readings demonstrated the maximum score of 10.0 AU. Based on our data, the cut-off value for LM diagnosis (25 ppm H2) using AIRE is 3.0 AU and it is effective for the identification of a response to lactose-containing foods in individuals experiencing LM, although its upper limit is only 81 ppm.


Assuntos
Testes Respiratórios/instrumentação , Intolerância à Lactose/diagnóstico , Lactose/metabolismo , Adulto , Testes Respiratórios/métodos , Feminino , Humanos , Masculino , Adulto Jovem
8.
Physiol Rep ; 7(13): e14108, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31257737

RESUMO

Lipid mediators including classical arachidonic acid-derived eicosanoids (e.g. prostaglandins and leukotrienes) and more recently identified specialized pro-resolving-mediator metabolites of the omega-3 fatty acids play essential roles in initiation, self-limitation, and active resolution of acute inflammatory responses. In this study, we examined the bioactive lipid mediator profile of human skeletal muscle at rest and following acute resistance exercise. Twelve male subjects completed a single bout of maximal isokinetic unilateral knee extension exercise and muscle biopsies were taken from the m.vastus lateralis before and at 2, 4, and 24 h of recovery. Muscle tissue lipid mediator profile was analyzed via liquid chromatography-mass spectrometry (LC-MS)-based targeted lipidomics. At 2 h postexercise, there was an increased intramuscular abundance of cyclooxygenase (COX)-derived thromboxanes (TXB2 : 3.33 fold) and prostaglandins (PGE2 : 2.52 fold and PGF2α : 1.77 fold). Resistance exercise also transiently increased muscle concentrations of lipoxygenase (LOX) pathway-derived leukotrienes (12-Oxo LTB4 : 1.49 fold and 20-COOH LTB4 : 2.91 fold), monohydroxy-eicosatetraenoic acids (5-HETE: 2.66 fold, 12-HETE: 2.83 fold, and 15-HETE: 1.69 fold) and monohydroxy-docosahexaenoic acids (4-HDoHE: 1.69 fold, 7-HDoHE: 1.58 fold and 14-HDoHE: 2.35 fold). Furthermore, the abundance of CYP pathway-derived epoxy- and dihydroxy-eicosatrienoic acids was increased in 2 h postexercise biopsies (5,6-EpETrE: 2.48 fold, 11,12-DiHETrE: 1.66 fold and 14,15-DiHETrE: 2.23 fold). These data reveal a range of bioactive lipid mediators as present within human skeletal muscle tissue and demonstrate that acute resistance exercise transiently stimulates the local production of both proinflammatory eicosanoids and pathway markers in specialized proresolving mediator biosynthesis circuits.

9.
J Nutr ; 149(9): 1511-1522, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31152658

RESUMO

BACKGROUND: Resistance exercise and dietary protein stimulate muscle protein synthesis (MPS). The rate at which proteins are digested and absorbed into circulation alters peak plasma amino acid concentrations and may modulate postexercise MPS. A novel mineral modified milk protein concentrate (mMPC), with identical amino acid composition to standard milk protein concentrate (MPC), was formulated to induce rapid aminoacidemia. OBJECTIVES: The aim of this study was to determine whether rapid aminoacidemia and greater peak essential amino acid (EAA) concentrations induced by mMPC would stimulate greater postresistance exercise MPS, anabolic signaling, and ribosome biogenesis compared to standard dairy proteins, which induce a small but sustained plasma essential aminoacidemia. METHODS: Thirty healthy young men (22.5 ± 3.0 y; BMI 23.8 ± 2.7 kg/m2) received primed constant infusions of l-[ring-13C6]-phenylalanine and completed 3 sets of leg presses and leg extensions at 80% of 1 repetition. Afterwards, participants were randomly assigned in a double-blind fashion to consume 25 g mMPC, MPC, or calcium caseinate (CAS). Vastus lateralis biopsies were collected at rest, and 2 and 4 h post exercise. RESULTS: Plasma EAA concentrations, including leucine, were 19.2-26.6% greater in the mMPC group 45-90 min post ingestion than in MPC and CAS groups (P < 0.001). Myofibrillar fractional synthetic rate from baseline to 4 h was increased by 82.6 ± 64.8%, 137.8 ± 72.1%, and 140.6 ± 52.4% in the MPC, mMPC, and CAS groups, respectively, with no difference between groups (P = 0.548). Phosphorylation of anabolic signaling targets (P70S6KThr389, P70S6KThr421/Ser424, RPS6Ser235/236, RPS6Ser240/244, P90RSKSer380, 4EBP1) were elevated by <3-fold at both 2 and 4 h post exercise in all groups (P < 0.05). CONCLUSIONS: The amplitude of plasma leucine and EAA concentrations does not modulate the anabolic response to resistance exercise after ingestion of 25 g dairy protein in young men. This trial was registered at http://www.anzctr.org.au/ as ACTRN12617000393358.

10.
Front Nutr ; 6: 91, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31249834

RESUMO

Progressive muscle loss with aging results in decreased physical function, frailty, and impaired metabolic health. Deficits in anabolic signaling contribute to an impaired ability for aged skeletal muscle to adapt in response to exercise and protein feeding. One potential contributing mechanism could be exerted by dysregulation of microRNAs (miRNAs). Therefore, the aim of this study was to determine if graded protein doses consumed after resistance exercise altered muscle miRNA expression in elderly men. Twenty-three senior men (67.9 ± 0.9 years) performed a bout of resistance exercise and were randomized to consume either a placebo, 20 or 40 g of whey protein (n = 8, n = 7, and n = 8, respectively). Vastus lateralis biopsies were collected before, 2 and 4 h after exercise. Expression of 19 miRNAs, previously identified to influence muscle phenotype, were measured via RT-PCR. Of these, miR-16-5p was altered with exercise in all groups (p = 0.032). Expression of miR-15a and-499a increased only in the placebo group 4 h after exercise and miR-451a expression increased following exercise only in the 40 g whey supplementation group. Changes in p-P70S6KThr389 and p-AktSer473 following exercise were correlated with alterations in miR-208a and-499a and-206 expression, irrespective of protein dose, suggesting a possible role for miRNA in the regulation of acute phosphorylation events during early hours of exercise recovery.

11.
Mol Nutr Food Res ; 63(8): e1800811, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30892810

RESUMO

SCOPE: MicroRNA are critical to the coordinated post-transcriptional regulation of gene expression, yet few studies have addressed the influence of habitual diet on microRNA expression. High protein diets impact cardiometabolic health and body composition in the elderly suggesting the possibility of a complex systems response. Therefore, high-throughput small RNA sequencing technology is applied in response to doubling the protein recommended dietary allowance (RDA) over 10 weeks in older men to examine alterations in circulating miRNAome. METHODS AND RESULTS: Older men (n = 31; 74.1 ± 0.6 y) are randomized to consume either RDA (0.8 g kg-1  day-1 ) or 2RDA (1.6 g kg-1  day-1 ) of protein for 10 weeks. Downregulation of five microRNAs (miR-125b-5p, -100-5p, -99a-5p, -23b-3p, and -203a) is observed following 2RDA with no changes in the RDA. In silico functional analysis highlights target gene enrichment in inflammation-related pathways. qPCR quantification of predicted inflammatory genes (TNFα, IL-8, IL-6, pTEN, PPP1CB, and HOXA1) in peripheral blood mononuclear cells shows increased expression following 2RDA diet (p ≤ 0.05). CONCLUSION: The study findings suggest a possible selective alteration in the post-transcriptional regulation of the immune system following a high protein diet. However, very few microRNAs are altered despite a large change in the dietary protein.


Assuntos
Ácidos Nucleicos Livres/sangue , Proteínas na Dieta/farmacologia , MicroRNAs/sangue , Idoso , Proteínas na Dieta/administração & dosagem , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamação/genética , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/fisiologia , Masculino , RNA Mensageiro , Recomendações Nutricionais
12.
Am J Physiol Cell Physiol ; 316(2): C293-C298, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30601673

RESUMO

Loss of muscle size and strength with aging is a major cause of morbidity. Although muscle size and strength are measured by imaging or fiber cross-sectional staining and exercise testing, respectively, the development of circulatory biomarkers for these phenotypes would greatly simplify identification of muscle function deficits. MicroRNAs (miRNAs) are short noncoding RNAs that regulate gene translation and, thereby, contribute to muscle phenotype. To assess circulatory miRNAs (c-miRNAs) applicability as potential biomarkers of muscular phenotypes, fasting plasma and muscle samples were obtained from 50 middle-aged healthy men [mean (SD); age: 48.8 yr (SD 4.5); BMI: 26.6 kg/m2 (SD 3.3)]. RT-PCR of 38 miRNAs with known regulatory function within skeletal muscle identified four c-miRNAs (miR-221, miR-451a, miR-361, and miR-146a) related to either total body lean mass, leg lean mass, and 50% thigh cross-sectional area (CSA), but not strength. There was no relationship with the expression of these miRNAs in muscle. Six miRNAs within muscle were correlated with whole body lean mass, leg lean mass, and isometric knee extension torque (miR-133a and miR-146a), and 50% thigh CSA (miR-486, miR-208b, miR-133b, and miR-208a). Only miR-23b demonstrated a relationship between tissue and circulatory expression; however, only 10% of the variance was explained. miR-146a in both plasma and muscle was related to phenotype; however, no relationship between plasma and muscle expression was evident. A different subset of miRNAs correlated to muscle phenotype in muscle compared with plasma samples, suggesting that c-miRNA biomarkers of muscle phenotype are likely unrelated to muscle expression in healthy individuals.


Assuntos
MicroRNA Circulante/sangue , Exercício/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/metabolismo , Absorciometria de Fóton/métodos , Adulto , Biomarcadores/sangue , Humanos , Masculino , Pessoa de Meia-Idade
13.
J Appl Physiol (1985) ; 126(3): 578-592, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30543499

RESUMO

The purpose of the present study was to investigate muscle hypertrophy, strength, and myonuclear and satellite cell (SC) responses to high-frequency blood flow-restricted resistance exercise (BFRRE). Thirteen individuals [24 ± 2 yr (mean ± SD), 9 men] completed two 5-day blocks of 7 BFRRE sessions, separated by a 10-day rest period. Four sets of unilateral knee extensions to voluntary failure at 20% of one repetition maximum (1RM) were conducted with partial blood flow restriction (90-100 mmHg). Muscle samples obtained before, during, 3 days, and 10 days after training were analyzed for muscle fiber area (MFA), myonuclei, SC, and mRNA and miRNA expression. Muscle size was measured by ultrasonography and magnetic resonance imaging and strength with 1RM knee extension. With the first block of BFRRE, SC number increased in both fiber types (70%-80%, P < 0.05), whereas type I and II MFA decreased by 6 ± 7% and 15 ± 11% ( P < 0.05), respectively. With the second block of training, muscle size increased by 6%-8%, whereas the number of SCs (type I: 80 ± 63%, type II: 147 ± 95%), myonuclei (type I: 30 ± 24%, type II: 31 ± 28%), and MFA (type I: 19 ± 19%, type II: 11 ± 19%) peaked 10 days after the second block of BFRRE, whereas strength peaked after 20 days of detraining (6 ± 6%, P < 0.05). Pax7- and p21 mRNA expression were elevated during the intervention, whereas myostatin, IGF1R, MyoD, myogenin, cyclinD1 and -D2 mRNA did not change until 3-10 days postintervention. High-frequency low-load BFRRE induced robust increases in SC, myonuclei, and muscle size but modest strength gains. Intriguingly, the responses were delayed and peaked 10-20 days after the training intervention, indicating overreaching. NEW & NOTEWORTHY In line with previous studies, we demonstrate that high-frequency low-load blood flow-restricted resistance exercise (HF-BFRRE) can elicit robust increases in satellite cell and myonuclei numbers, along with gains in muscle size and strength. However, our results also suggest that these processes can be delayed and that with very strenuous HF-BFRRE, there may even be transient muscle fiber atrophy, presumably because of accumulated stress responses. Our findings have implications for the prescription of BFR exercise.

14.
Clin Nutr ; 38(4): 1913-1920, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30017243

RESUMO

BACKGROUND & AIMS: Human milk (HM) contains a wide array of non-nutritive bioactive elements, including glucocorticoid hormones (glucocorticoid; cortisol and cortisone). The relationship between milk-borne glucocorticoids, measures of maternal health and patterns of breast-feeding is not yet established. This study was conducted to determine the influence of maternal and infant related biological and socio-demographic factors on the levels of glucocorticoids hormones in HM. METHODS: Samples were obtained from lactating mothers (n = 656) participating in the Finnish cohort the STEPS study (Steps to the Healthy Development and Well-being of Children) when the infants were 11.29 (±2.6) weeks of age. Glucocorticoids (both cortisol and cortisone) concentrations were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Maternal demographics, biological and social factors were obtained using hospital records and self-reported diaries and questionnaires. RESULTS: The majority of women reported that they were exclusively breastfeeding at the time of sample donation (51.2%). For all collected samples, cortisone (9.55 ± 3.44 ng/ml) was the predominant hormone and cortisol (7.39 ± 5.97 ng/ml) was present in all samples. Strong and positive correlation was found between cortisol and cortisone (r = 0.60, p=<0.0001). Cortisone was statistically different between overweight, normal and underweight women (p = 0.01) for cortisol no difference was seen (p = 0.96). Whilst, preterm birth (born before 37 week gestation) was positively associated with both cortisol (p = 0.04) and cortisone (p = 0.01). There was also a significant but weaker negative relationship between mothers educational status and cortisol (p = 0.05) and no effect was seen for cortisone (p = 0.82). Interestingly, no significant differences was found in glucocorticoid concentrations between exclusive and partial breastfeeding women. CONCLUSION: HM contains glucocorticoids hormones. The concentrations are influenced by the varying maternal factors including maternal weight, preterm birth and maternal educational status, suggesting the possible role of maternal biological and social influences on milk hormonal composition. Interestingly, there was no influence of feeding patterns on HM glucocorticoids. Further analysis is required to fully explore the relationship with measures of maternal stress, including mother's glucocorticoid status.

15.
Eur J Nutr ; 58(3): 1047-1054, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29445912

RESUMO

PURPOSE: Elemental deficiencies are highly prevalent and have a significant impact on health. However, clinical monitoring of plasma elemental responses to foods remains largely unexplored. Data from in vitro studies show that red meat (beef) is a highly bioavailable source of several key elements, but cooking method may influence this bioavailability. We therefore studied the postprandial responses to beef steak, and the effects of two different cooking methods, in healthy young males. METHODS: In a randomized cross-over controlled trial, healthy males (n = 12, 18-25 years) were fed a breakfast of beef steak (270 ± 20 g) in which the meat was either pan-fried (PF) or sous-vide (SV) cooked. Baseline and postprandial blood samples were collected and the plasma concentrations of 15 elements measured by inductively coupled plasma-mass spectrometry (ICP-MS). RESULTS: Concentrations of Fe and Zn changed after meal ingestion, with plasma Fe increasing (p < 0.001) and plasma Zn decreasing (p < 0.05) in response to both cooking methods. The only potential treatment effect was seen for Zn, where the postprandial area under the curve was lower in response to the SV meal (2965 ± 357) compared to the PF meal (3190 ± 310; p < 0.05). CONCLUSIONS: This multi-element approach demonstrated postprandial responsiveness to a steak meal, and an effect of the cooking method used. This suggests the method would provide insight in future elemental metabolic studies to evaluate responses to meat-based meals, including longer-term interventions in more specifically defined cohorts to clearly establish the role of red meat as an important source of elements.


Assuntos
Culinária/métodos , Temperatura Alta , Ferro na Dieta/sangue , Carne Vermelha , Zinco/sangue , Adolescente , Adulto , Disponibilidade Biológica , Estudos Cross-Over , Humanos , Masculino , Período Pós-Prandial , Valores de Referência , Adulto Jovem
16.
Med Sci Sports Exerc ; 51(2): 288-298, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30188363

RESUMO

PURPOSE: To investigate the effects of blood flow-restricted resistance exercise (BFRRE) on myofiber areas (MFA), number of myonuclei and satellite cells (SC), muscle size and strength in powerlifters. METHODS: Seventeen national level powerlifters (25 ± 6 yr [mean ± SD], 15 men) were randomly assigned to either a BFRRE group (n = 9) performing two blocks (weeks 1 and 3) of five BFRRE front squat sessions within a 6.5-wk training period, or a conventional training group (Con; n = 8) performing front squats at 60%-85% of one-repetition maximum (1RM). The BFRRE consisted of four sets (first and last set to voluntary failure) at ~30% of 1RM. Muscle biopsies were obtained from m. vastus lateralis (VL) and analyzed for MFA, myonuclei, SC and capillaries. Cross-sectional areas (CSA) of VL and m. rectus femoris were measured by ultrasonography. Strength was evaluated by maximal voluntary isokinetic torque (MVIT) in knee extension and 1RM in front squat. RESULTS: BFRRE induced selective increases in type I MFA (BFRRE: 12% vs Con: 0%, P < 0.01) and myonuclear number (BFRRE: 18% vs Con: 0%, P = 0.02). Type II MFA was unaltered in both groups. BFRRE induced greater changes in VL CSA (7.7% vs 0.5%, P = 0.04), which correlated with the increases in MFA of type I fibers (r = 0.81, P = 0.02). No group differences were observed in SC and strength changes, although MVIT increased with BFRRE (P = 0.04), whereas 1RM increased in Con (P = 0.02). CONCLUSIONS: Two blocks of low-load BFRRE in the front squat exercise resulted in increased quadriceps CSA associated with preferential hypertrophy and myonuclear addition in type 1 fibers of national level powerlifters.


Assuntos
Fibras Musculares de Contração Lenta/citologia , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/irrigação sanguínea , Treinamento de Resistência/métodos , Adulto , Contagem de Células , Núcleo Celular , Feminino , Humanos , Masculino , Microcirculação , Fibras Musculares de Contração Lenta/fisiologia , Músculo Esquelético/diagnóstico por imagem , RNA/metabolismo , Fluxo Sanguíneo Regional , Células Satélites de Músculo Esquelético/citologia , Ultrassonografia , Adulto Jovem
17.
Arch Physiol Biochem ; : 1-12, 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30451544

RESUMO

CONTEXT: Levels of ketone bodies are altered in both acute pancreatitis and type 1 and type 2 diabetes. However, the role of ketone bodies in the pathogenesis of abnormal glucose metabolism after pancreatitis is largely unknown. OBJECTIVE: To investigate the associations between ketone bodies and glucose homeostasis in individuals with post-pancreatitis prediabetes (PPP) versus normoglycaemia after pancreatitis (NAP). METHODS: Fasting blood samples were analysed for acetoacetate, ß-hydroxybutyrate, and markers of glucose metabolism at a median of 26 months after acute pancreatitis. A series of linear regression analyses were conducted adjusting for patient- and pancreatitis-related characteristics. RESULTS: The study included 27 individuals with PPP and 52 with NAP. ß-hydroxybutyrate was significantly associated with fasting plasma glucose (p = .002) and explained 26.2% of its variance in PPP, but not in NAP (p = .814; 0%). Acetoacetate was not significantly associated with fasting plasma glucose in both PPP (p = .681) or NAP (p = .661). CONCLUSIONS: An inverse association between ß-hydroxybutyrate and fasting plasma glucose characterises PPP and this may have translational implications.

18.
Nutrients ; 10(10)2018 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-30322081

RESUMO

Fortified milk drinks are predominantly manufactured from bovine (cow) sources. Alternative formulations include those prepared with hydrolysed bovine milk proteins or from alternate bovidae species, such as caprine (goat) milk. Currently, there is little data on protein digestive and metabolic responses following ingestion of fortified milk drinks. To examine the digestive and metabolic responses to commercially-available fortified milks, young adults (n = 15 males: 15 females), in a randomised sequence, ingested isonitrogenous quantities of whole cow-protein (WC), whole goat-protein (WG), or partially-hydrolysed whey cow-protein (HC), commercial fortified milks. Plasma amino acid (AA) and hormonal responses were measured at baseline and again at 5 h after ingestion. Paracetamol recovery, breath hydrogen, and subjective digestive responses were also measured. Postprandial plasma AA was similar between WC and WG, while AA appearance was suppressed with HC. Following HC, there was a negative incremental AUC in plasma branched-chain AAs. Further, HC had delayed gastric emptying, increased transit time, and led to exaggerated insulin and GLP-1 responses, in comparison to whole protein formulas. Overall, WC and WG had similar protein and digestive responses with no differences in digestive comfort. Contrastingly, HC led to delayed gastric emptying, attenuated AA appearance, and a heightened circulating insulin response.


Assuntos
Proteínas na Dieta/metabolismo , Digestão , Alimentos Fortificados , Leite/química , Período Pós-Prandial , Hidrolisados de Proteína/metabolismo , Proteínas do Soro do Leite/metabolismo , Adolescente , Adulto , Aminoácidos/sangue , Animais , Bebidas , Glicemia/metabolismo , Bovinos , Feminino , Esvaziamento Gástrico/efeitos dos fármacos , Trânsito Gastrointestinal/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/sangue , Cabras , Humanos , Insulina/sangue , Masculino , Proteínas do Leite/metabolismo , Adulto Jovem
19.
Front Physiol ; 9: 1336, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30356878

RESUMO

The transcriptional coactivators peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and PGC-1ß are positive regulators of skeletal muscle mass and energy metabolism; however, whether they influence muscle growth and metabolic adaptations via increased protein synthesis is not clear. This study revealed PGC-1α or PGC-1ß overexpression in C2C12 myotubes increased protein synthesis and myotube diameter under basal conditions and attenuated the loss in protein synthesis following the treatment with the catabolic agent, dexamethasone. To investigate whether PGC-1α or PGC-1ß signal through the Akt/mTOR pathway to increase protein synthesis, treatment with the PI3K and mTOR inhibitors, LY294002 and rapamycin, respectively, was undertaken but found unable to block PGC-1α or PGC-1ß's promotion of protein synthesis. Furthermore, PGC-1α and PGC-1ß decreased phosphorylation of Akt and the Akt/mTOR substrate, p70S6K. In contrast to Akt/mTOR inhibition, the suppression of ERRα, a major effector of PGC-1α and PGC-1ß activity, attenuated the increase in protein synthesis and myotube diameter in the presence of PGC-1α or PGC-1ß overexpression. To characterize further the biological processes occurring, gene set enrichment analysis of genes commonly regulated by both PGC-1α and PGC-1ß was performed following a microarray screen. Genes were found enriched in metabolic and mitochondrial oxidative processes, in addition to protein translation and muscle development categories. This suggests concurrent responses involving both increased metabolism and myotube protein synthesis. Finally, based on their known function or unbiased identification through statistical selection, two sets of genes were investigated in a human exercise model of stimulated protein synthesis to characterize further the genes influenced by PGC-1α and PGC-1ß during physiological adaptive changes in skeletal muscle.

20.
Nutrients ; 10(10)2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30326639

RESUMO

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.


Assuntos
Aminoácidos de Cadeia Ramificada/sangue , Laticínios , Proteínas do Leite/administração & dosagem , Adulto , Biomarcadores/sangue , Glicemia/metabolismo , Comportamento Alimentar , Feminino , Voluntários Saudáveis , Humanos , Insulina/sangue , Resistência à Insulina , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Proteínas do Leite/sangue , Nova Zelândia , Recomendações Nutricionais , Fatores de Tempo
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