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BACKGROUND: Although nutrition and exercise both influence bone metabolism, little is currently known about their interaction, or whether nutritional intervention can modulate the bone biomarker response to acute exercise. Improved understanding of the relationships between nutrition, exercise and bone metabolism may have substantial potential to inform nutritional interventions to protect the bone health of exercising individuals, and to elucidate mechanisms by which exercise and nutrition influence bone. OBJECTIVE: The aim was to synthesise available evidence related to the influence of nutrition on the response of the bone biomarkers procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX-1) to acute exercise, using a systematic review and meta-analytic approach. METHODS: Studies evaluating the influence of nutritional status or intervention on the bone biomarker response to an acute exercise bout were included and separated into four categories: (1) feeding status and energy availability, (2) macronutrients, (3) micronutrients and (4) other. Studies conducted on healthy human populations of any age or training status were included. Meta-analysis was conducted when data from at least five studies with independent datasets were available. In the case of insufficient data to warrant meta-analysis, results from individual studies were narratively synthesised and standardised mean effect sizes visually represented. RESULTS: Twenty-two articles were included. Of these, three investigated feeding status or energy availability, eight macronutrients, eight micronutrients (all calcium) and six other interventions including dairy products or collagen supplementation. Three studies had more than one intervention and were included in all relevant outcomes. The largest and most commonly reported effects were for the bone resorption marker CTX-1. Meta-analysis indicated that calcium intake, whether provided via supplements, diet or infusion, reduced exercise-induced increases in CTX-1 (effect size - 1.1; 95% credible interval [CrI] - 2.2 to - 0.05), with substantially larger effects observed in studies that delivered calcium via direct infusion versus in supplements or foods. Narrative synthesis suggests that carbohydrate supplementation may support bone during acute exercise, via reducing exercise-induced increases in CTX-1. Conversely, a low-carbohydrate/high-fat diet appears to induce the opposite effect, as evidenced by an increased exercise associated CTX-1 response, and reduced P1NP response. Low energy availability may amplify the CTX-1 response to exercise, but it is unclear whether this is directly attributable to energy availability or to the lack of specific nutrients, such as carbohydrate. CONCLUSION: Nutritional intervention can modulate the acute bone biomarker response to exercise, which primarily manifests as an increase in bone resorption. Ensuring adequate attention to nutritional factors may be important to protect bone health of exercising individuals, with energy, carbohydrate and calcium availability particularly important to consider. Although a wide breadth of data were available for this evidence synthesis, there was substantial heterogeneity in relation to design and intervention characteristics. Direct and indirect replication is required to confirm key findings and to generate better estimates of true effect sizes.
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Ecological momentary assessment (EMA) is a way to evaluate experiences in everyday life. It is a powerful research tool but can be complex and challenging for beginners. Application of EMA in audiological research brings with it opportunities and challenges that differ from other research disciplines. This tutorial discusses important considerations when conducting EMA studies in hearing care. While more research is needed to develop specific guidelines for the various potential applications of EMA in hearing research, we hope this article can alert hearing researchers new to EMA to pitfalls when using EMA and help strengthen their study design. The current article elaborates study design details, such as choice of participants, representativeness of the study period for participants' lives, and balancing participant burden with data requirements. Mobile devices and sensors to collect objective data on the acoustic situation are reviewed alongside different possibilities for EMA setups ranging from online questionnaires paired with a timer to proprietary apps that also have access to parameters of a hearing device. In addition to considerations for survey design, a list of questionnaire items from previous studies is provided. For each item, an example and a list of references are given. EMA typically provides data sets that are rich but also challenging in that they are noisy, and there is often unequal amount of data between participants. After recommendations on how to check the data for compliance, reactivity, and careless responses, methods for statistical analysis on the individual level and on the group level are discussed including special methods for direct comparison of hearing device programs.
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Current guidelines for prolonged altitude exposure suggest altitude levels ranging from 2000 to 2500 m to optimize an increase in total hemoglobin mass (Hbmass). However, natural low altitude locations (<2000 m) remain popular, highlighting the interest to investigate any possible benefit of low altitude camps for endurance athletes. Ten elite racewalkers (4 women and 6 men) underwent a 4-week "live high-train high" (LHTH) camp at an altitude of 1720 m (PIO2 = 121 mmHg; 20.1°C; 67% relative humidity [RH]), followed by a 3-week tapering phase (20 m; PIO2 = 150 mmHg; 28.3°C; 53% RH) in preparation for the World Athletics Championships (WC). Venous blood samples were withdrawn weekly during the entire observation period. In addition, blood volumes were determined weekly by carbon monoxide rebreathing during altitude exposure and 2 weeks after return to sea level. High-level performances were achieved at the WC (five placings among the Top 10 WC races and three all-time career personal bests). A slight but significant increase in absolute (+1.7%, p = 0.03) and relative Hbmass (+2.3%, p = 0.02) was observed after 4-week LHTH. In addition, as usually observed during LHTH protocols, weekly training distance (+28%, p = 0.02) and duration (+30%, p = 0.04) significantly increased during altitude compared to the pre-LHTH period. Therefore, although direct causation cannot be inferred, these results suggest that the combination of increased training load at low altitudes with a subsequent tapering period in a warm environment is a suitable competition-preparation strategy for elite endurance athletes.
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Altitude , Desempenho Atlético , Hemoglobinas , Humanos , Masculino , Feminino , Desempenho Atlético/fisiologia , Adulto , Hemoglobinas/análise , Adulto Jovem , Atletas , Resistência Física/fisiologia , Volume Sanguíneo/fisiologia , Temperatura Alta , Condicionamento Físico Humano/métodos , Condicionamento Físico Humano/fisiologiaRESUMO
Occupational lung/thoracic diseases are a major global public health issue. They comprise a diverse spectrum of health conditions with complex pathology, most of which arise following chronic heavy workplace exposures to various mineral dusts, metal fumes, or following inhaled organic particulate reactions. Many occupational lung diseases could become irreversible; thus accurate diagnosis is mandatory to minimize dust exposure and consequently reduce damage to the respiratory system. Lung biopsy is usually required when exposure history is inconsistent with imaging, in case of unusual or new exposures, in case of unexpected malignancy, and in cases in which there are claims for personal injury and legal compensation. In this paper, we provide an overview of the most frequent occupational lung diseases with a focus on pathological diagnosis. This is a paper that summarizes the expert opinion from a group of European pathologists, together with contributions from other specialists who are crucial for the diagnosis and management of these diseases. Indeed, tight collaboration of all specialists involved in the workup is mandatory as many occupational lung diseases are misdiagnosed or go unrecognized. This document provides a guide for pathologists in practice to facilitate the accurate diagnosis of occupational lung disease. The review article reports relevant topics discussed during an educational course held by expert pathologists, active members of the Pulmonary Pathology Working Group of the European Society of Pathology. The course was endorsed by the University of Padova as a "winter school" (selected project in the call for "Shaping a World-class University" 2022).
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Pneumopatias , Doenças Profissionais , Patologistas , Humanos , Pneumopatias/diagnóstico , Pneumopatias/patologia , Doenças Profissionais/diagnóstico , Doenças Profissionais/patologia , Exposição Ocupacional/efeitos adversos , Europa (Continente) , Prova PericialRESUMO
Hormonal contraceptive (HC) users have a different ovarian hormonal profile compared to eumenorrheic women. Due to the prevalence of HC use amongst sportswomen, there has been increased research efforts to understand their impact on exercise performance. The aim was to audit this research. Studies identified were assessed for HC type, athlete calibre, performance outcome, study design, and quality of methodological control regarding ovarian hormonal profiles. Sixty-eight different HCs were reported across 61 studies. Monophasic combined oral contraceptive (OCP) pills represented 60% of HCs, followed by other pills [34%, phasic-combined, progestogen-only, and un-specified], phasic and long acting reversible contraceptives [5%, vaginal ring, patch, implant, injection, intrauterine system] and unspecified HCs (1%). Eleven percent of participants using HCs were classified as highly trained or elite/international with no participants being classed as world class. Whilst the number of studies involving HCs has increased two-fold over the past decade, the number of studies ranked as gold standard has not increased (HC; 2003-57%, 2011-55%, 2022-43%. OCP; 2003-14%, 2011-17%, 2022-12%). Future research assessing HCs and exercise performance should adopt high-quality research designs and include a broader range of HCs in highly trained to world-class populations to increase the reach and impact of research in this area.
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Desempenho Atlético , Humanos , Feminino , Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Contraceptivos Hormonais/administração & dosagem , Anticoncepcionais Orais Hormonais/administração & dosagem , Projetos de PesquisaRESUMO
We examined performance across one menstrual cycle (MC) and 3 weeks of hormonal contraceptives (HC) use to identify whether known fluctuations in estrogen and progesterone/progestin are associated with functional performance changes. National Rugby League Indigenous Women's Academy athletes [n = 11 naturally menstruating (NM), n = 13 using HC] completed performance tests [countermovement jump (CMJ), squat jump (SJ), isometric mid-thigh pull, 20 m sprint, power pass and Stroop test] during three phases of a MC or three weeks of HC usage, confirmed through ovulation tests alongside serum estrogen and progesterone concentrations. MC phase or HC use did not influence jump height, peak force, sprint time, distance thrown or Stroop effect. However, there were small variations in kinetic and kinematic CMJ/SJ outputs. NM athletes produced greater mean concentric power in MC phase four than one [+0.41 W·kg-1 (+16.8%), p = 0.021] during the CMJ, alongside greater impulse at 50 ms at phase one than four [+1.7 N·s (+4.7%), p = 0.031] during the SJ, without differences between tests for HC users. Among NM athletes, estradiol negatively correlated with mean velocity and power (r = -0.44 to -0.50, p < 0.047), progesterone positively correlated with contraction time (r = 0.45, p = 0.045), and both negatively correlated with the rate of force development and impulse (r = -0.45 to -0.64, p < 0.043) during the SJ. During the CMJ, estradiol positively correlated to 200 ms impulse (r = 0.45, p = 0.049) and progesterone to mean power (r = 0.51, p = 0.021). Evidence of changes in testing performance across a MC, or during active HC use, is insufficient to justify "phase-based testing"; however, kinetic or kinematic outputs may be altered in NM athletes.
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Desempenho Atlético , Futebol Americano , Ciclo Menstrual , Progesterona , Humanos , Feminino , Ciclo Menstrual/fisiologia , Ciclo Menstrual/efeitos dos fármacos , Desempenho Atlético/fisiologia , Progesterona/sangue , Adulto Jovem , Futebol Americano/fisiologia , Estradiol/sangue , Adulto , Atletas , Anticoncepcionais Orais Hormonais/administração & dosagem , Anticoncepcionais Orais Hormonais/farmacologia , Força Muscular/efeitos dos fármacos , Força Muscular/fisiologia , Fenômenos Biomecânicos , Estrogênios/sangue , Estrogênios/administração & dosagem , Teste de EsforçoRESUMO
AIMS: Next generation sequencing (NGS) on tumour tissue is integral to the delivery of personalised medicine and targeted therapy. NGS on liquid biopsy, a much less invasive technology, is an emerging clinical tool that has rapidly expanded clinical utility. Gene mutations in cell-free total nucleic acids (cfTNA) circulating in the blood are representative of whole tumour biology and can reveal different mutations from different tumour sites, thus addressing tumour heterogeneity challenges. METHODS: The novel Ion Torrent Genexus NGS system with automated sample preparation, onboard library preparation, templating, sequencing, data analysis and Oncomine Reporter software was used. cfTNA extracted from plasma was verified with the targeted pan-cancer (~50 genes) Oncomine Precision Assay (OPA). Assessment criteria included analytical sensitivity, specificity, limits of detection (LOD), accuracy, repeatability, reproducibility and the establishment of performance metrics. RESULTS: An ISO 15189 accredited, minimally invasive cfTNA NGS diagnostic service has been implemented. High sensitivity (>83%) and specificity between plasma and tissue were observed. A sequencing LOD of 1.2% was achieved when the depth of coverage was >22 000×. A reduction (>68%) in turnaround time (TAT) of liquid biopsy results was achieved: 5 days TAT for in-house analysis from sample receipt to a final report issued to oncologists as compared with >15 days from reference laboratories. CONCLUSION: Tumour-derived somatic variants can now be reliably assessed from plasma to provide minimally invasive tumour profiling. Successful implementation of this accredited service resulted in:Appropriate molecular profiling of patients where tumour tissue is unavailable or inaccessible.Rapid TAT of plasma NGS results.
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OBJECTIVES: The application of continuous glucose monitors (CGMs) to measure interstitial glucose in athletic populations is limited by the lack of accepted athlete-specific reference values. The aim of this study was to develop athlete-specific reference ranges for glycemic variability under standardized diet and exercise conditions. METHODS: A total of 12 elite racewalkers (n = 7 men, 22.4 ± 3.5 years, VO2max 61.6 ± 7.3 mL kg-1 min-1) completed two 4-d trials separated by 4-d. Athletes were provided a high-energy, high-carbohydrate diet (225 ± 1.6 kJ kg-1 day-1, 8.4 ± 0.3 g kg-1 day-1 carbohydrate) and completed standardized daily exercise. The timing of food consumed and exercise undertaken were matched each day across the 4-d trials. Interstitial glucose data were collected via Freestyle Libre 2 CGMs. Glycemic variability was calculated as the mean amplitude of glycemic excursions (MAGEs), mean of daily differences (MODD), and standard deviation (SD). RESULTS: Twenty-four hour MODD, MAGE, and SD for interstitial glucose were 12.6 ± 1.8 mg/dL (0.7 ± 0.1 mmol/L), 36.0 ± 5.4 mg/dL (2.0 ± 0.3 mmol/L), and 16.2 ± 1.8 mg/dL (0.9 ± 0.1 mmol/L), respectively. Twenty-four hour mean glucose (MG; 102.6 ± 5.4 mg/dL [5.7 ± 0.3 mmol/L]) was higher than overnight (91.8 ± 5.4 mg/dL [5.1 ± 0.3 mmol/L]; P < .0001) and was lower in women than men (99.0 ± 3.6 mg/dL [5.5 ± 0.2 mmol/L] vs 104.4 ± 3.6 mg/dL [5.8 ± 0.2 mmol/L]; P = .059, d = 1.4). CONCLUSIONS: This study provides reference indices under standardized diet and exercise conditions for glycemic variability derived from CGMs in endurance athletes which are similar than previously reported for healthy individuals, despite strenuous daily training and a high daily energy and carbohydrate diet.
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Case description: We describe a case of a patient treated with pembrolizumab (an immune checkpoint inhibitor) for metastatic scalp melanoma. He had a previous history of colorectal cancer, prostatic cancer and chronic polymyalgia rheumatica. The patient was known to have a stable ascending aortic aneurysm of 4.5 cm. However, he developed a rapid expansion of the ascending aortic aneurysm with the size crossing the threshold for surgery. The patient was referred to the cardiothoracic surgery service for intervention and he subsequently underwent surgery. The patient was electively admitted one week later for resection of aortic aneurysm, aortoplasty and external graft fixation. Pathologically, gross evidence of dissection was not identified; however, the histological analysis of the media showed laminar medial necrosis, multifocal in nature, with occasional clusters of histiocytic cells appreciated at their edge reminiscent of that seen in an inflammatory aortitis (granulomatous/giant cell type). Discussion: Immune checkpoint inhibitor-induced aortitis is becoming increasingly evident, and its presentation can vary. It has been discovered incidentally on surveillance imaging with the use of nivolumab. In other cases, patients have been symptomatic to severely symptomatic. Atezolizumab with carboplatin and etoposide has been reported to cause abdominal aortitis which was responsive to corticosteroids and subsequent discontinuation of atezolizumab. Pembrolizumab has been linked to a case of transverse aortic arch aortitis. In our case, the inflammatory aortitis due to pembrolizumab was the cause of the rapid expansion of the ascending aortic aneurysm. Conclusion: Patients with known aortic aneurysms should undergo careful surveillance when commencing immune-checkpoint inhibitor therapy. LEARNING POINTS: Immune checkpoint inhibitors are being increasingly used in the treatment of metastatic malignancy. However, they are a relatively new group of medications, and the side effect profile of each is yet to be fully recognised. Aortitis has occurred with several different immune checkpoint inhibitors.Patients with known aortic aneurysms should undergo careful surveillance when commencing immune checkpoint inhibitors.All interventional therapeutic options should be considered early in these patients on the development of aneurysmal expansion.
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BACKGROUND: Cognitive behavioural therapy (CBT) for tinnitus management is effective and widely recommended by national and international practice guidelines. However, all the evidence for CBT so far has come from Psychologist-led programs, and the potential role of Audiologists in providing CBT for tinnitus remains an important consideration. OBJECTIVES: This study sets out to systematically map the body of literature relating to Audiologist-provided CBT for tinnitus, in order to summarise the current state of evidence and determine directions for future research. ELIGIBILITY CRITERIA: Sources were eligible for inclusion if they addressed the concept of Audiologist-provided CBT. No restrictions were imposed on the date of publication. Only sources published in English were included. SOURCES OF EVIDENCE: A wide range of primary and secondary literature sources were sought. CHARTING METHODS: Data from included sources were charted systematically using a pre-designed data charting form. RESULTS: Of the 267 identified sources, 30 were included in this review. This included both primary and secondary literature sources. Primary sources were compared and showed variation across Audiologist-provided CBT programs both in terms of procedural details and from a research standpoint. CONCLUSIONS: A growing body of evidence has addressed the concept of Audiologist-provided CBT. Directions for future research include further primary research with an increased focus on face-to-face Audiologist-provided CBT, and a comparison of the outcomes of Audiologist-provided vs. Psychologist-provided CBT.
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The cyclical changes in sex hormones across the menstrual cycle (MC) are associated with various biological changes that may alter resting metabolic rate (RMR) and body composition estimates. Hormonal contraceptive (HC) use must also be considered given their impact on endogenous sex hormone concentrations and synchronous exogenous profiles. The purpose of this study was to determine if RMR and dual-energy X-ray absorptiometry body composition estimates change across the MC and differ compared with HC users. This was accomplished during a 5-week training camp involving naturally cycling athletes (n = 11) and HC users (n = 7 subdermal progestin implant, n = 4 combined monophasic oral contraceptive pill, n = 1 injection) from the National Rugby League Indigenous Women's Academy. MC phase was retrospectively confirmed via serum estradiol and progesterone concentrations and a positive ovulation test. HC users had serum estradiol and progesterone concentrations assessed at the time point of testing. Results were analyzed using general linear mixed model. There was no effect of MC phase on absolute RMR (p = .877), relative RMR (p = .957), or dual-energy X-ray absorptiometry body composition estimates (p > .05). There was no effect of HC use on absolute RMR (p = .069), relative RMR (p = .679), or fat mass estimates (p = .766), but HC users had a greater fat-free mass and lean body mass than naturally cycling athletes (p = .028). Our findings suggest that RMR and dual-energy X-ray absorptiometry body composition estimates do not significantly differ due to changes in sex hormones in a group of athletes, and measurements can be compared between MC phases or with HC usage without variations in sex hormones causing additional noise.
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Absorciometria de Fóton , Metabolismo Basal , Composição Corporal , Estradiol , Ciclo Menstrual , Progesterona , Humanos , Feminino , Composição Corporal/efeitos dos fármacos , Metabolismo Basal/efeitos dos fármacos , Ciclo Menstrual/efeitos dos fármacos , Adulto Jovem , Estradiol/sangue , Progesterona/sangue , Adulto , Estudos Retrospectivos , Contraceptivos Hormonais/administração & dosagem , Contraceptivos Hormonais/farmacologia , Atletas , AdolescenteRESUMO
The aim of this audit was to quantify female representation in research on heat adaptation. Using a standardized audit tool, the PubMed database was searched for heat adaptation literature from inception to February 2023. Studies were included if they investigated heat adaptation among female and male adults (≥18-50 years) who were free from noncommunicable diseases, with heat adaptation the primary or secondary outcome of interest. The number and sex of participants, athletic caliber, menstrual status, research theme, journal impact factor, Altmetric score, Field-Weighted Citation Impact, and type of heat exposure were extracted. A total of 477 studies were identified in this audit, including 7,707 participants with â¼13% of these being female. Most studies investigated male-only cohorts (â¼74%, n = 5,672 males), with â¼5% (n = 360 females) including female-only cohorts. Of the 126 studies that included females, only 10% provided some evidence of appropriate methodological control to account for ovarian hormone status, with no study meeting best-practice recommendations. Of the included female participants, 40% were able to be classified to an athletic caliber, with 67% of these being allocated to Tier 2 (i.e., trained/developmental) or below. Exercise heat acclimation was the dominant method of heat exposure (437 interventions), with 21 studies investigating sex differences in exercise heat acclimation interventions. We recommend that future research on heat adaptation in female participants use methodological approaches that consider the potential impact of sexual dimorphism on study outcomes to provide evidence-based guidelines for female athletes preparing for exercise or competition in hot conditions.
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Desempenho Atlético , Termotolerância , Adulto , Humanos , Masculino , Feminino , Aclimatação , Temperatura Alta , Exercício FísicoRESUMO
PURPOSE: The purpose of this study is to describe the implementation of a novel research protocol for conducting research with highly trained female athletes, including characterizing menstrual cycle (MC) function, hormonal profiles and symptoms of the participating athletes. METHODS: Twenty-four Australian First Nation female Rugby League athletes completed this study, which involved 11 wk of cycle tracking, followed by attendance at a 5-wk training camp. Throughout the study, athletes completed a daily survey, reporting their MC function and any associated symptoms. During the training camp, athletes reported to the laboratory on three occasions and provided a venous blood sample, which was analyzed for reproductive hormones. For naturally cycling athletes (athleteNC, n = 11), this included phase 1, 2, and 4 of the menstrual cycle, whereas athletes using hormonal contraception (athleteHC; n = 13) were tested at three equally spaced time points in which consistent exogenous hormone provision occurred. RESULTS: In the athleteNC cohort, just one athlete reached criteria for classification as eumenorrheic, with five athletes showing evidence of MC dysfunction. The prevalence of symptoms on any given day was similar between athleteNC (33.7%) and athleteHC (22.9%; P = 0.376); however, more symptoms were reported in athleteNC, suggesting that they were more likely to report multiple symptoms. Regardless of MC function, there was a significant, positive association between bleeding and symptoms ( P < 0.001), where athletes were more likely to report one or more symptoms on bleeding (50.1%) compared with nonbleeding days (22.0%). CONCLUSIONS: We describe an innovative strategy to investigate the effect of MC function and MC phase in a high-performance sport environment, including approaches to address the challenges of undertaking research with female athletes with MC variability and those using exogenous hormonal therapies.
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Atletas , Esportes , Humanos , Feminino , Austrália , Ciclo Menstrual , CiclismoRESUMO
PURPOSE: We examined iron absorption and its regulation during two common scenarios experienced by endurance athletes. Our aims were to: (i) compare the effects of preexercise versus postexercise iron intake on iron absorption; and (ii) compare the impact of training at altitude (1800 m) on iron absorption preexercise. METHODS: Male runners (n = 18) completed three exercise trials over a 5-wk period, each preceded by 24 h of standardized low-iron diets. First, athletes completed two 60-min treadmill running trials at 65% VÌO2max at near sea-level (580 m). In a randomized order, preexercise and postexercise test meals labeled with 4 mg of 57Fe or 58Fe were consumed 30 min before or 30 min after exercise. Then, the same exercise trial was performed after living and training at altitude (~1800 m) for 7 d, with the labeled test meal consumed 30 min preexercise. We collected venous blood samples preexercise and postexercise for markers of iron status and regulation, and 14 d later to measure erythrocyte isotope incorporation. RESULTS: No differences in fractional iron absorption were evident when test meals were consumed preexercise (7.3% [4.4, 12.1]) or postexercise (6.2% [3.1, 12.5]) (n = 18; P = 0.058). Iron absorption preexercise was greater at altitude (18.4% [10.6, 32.0]) than at near sea-level (n = 17; P < 0.001) and hepcidin concentrations at altitude were lower at rest and 3 h postexercise compared with near sea level (P < 0.001). CONCLUSIONS: In an acute setting, preexercise and postexercise iron absorption is comparable if consumed within 30 min of exercise. Preexercise iron absorption increases 2.6-fold at altitude compared with near sea-level, likely due to the homeostatic response to provide iron for enhanced erythropoiesis and maintain iron stores.
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Ferro , Corrida , Humanos , Masculino , Ferro/metabolismo , Corrida/fisiologia , Exercício Físico/fisiologia , Eritrócitos/metabolismo , AtletasRESUMO
A low carbohydrate, high fat (LCHF) diet in athletes increases fat oxidation but impairs sports performance, potentially due to impaired exercise economy. Dietary nitrate supplementation can improve exercise economy via an increase in nitric oxide production, which is initiated by the reduction of nitrate to nitrite within the oral cavity. This reaction is dependent on the presence of nitrate-reducing oral bacteria, which can potentially be altered by dietary changes, including a LCHF diet. This study explored the effect of a LCHF diet on the oral microbiome and subsequent changes to plasma nitrite concentration following nitrate supplementation. Following five days of LCHF or high carbohydrate (HCHO) control dietary intervention, highly trained male race walkers consumed 140 mL beetroot juice containing 8.4 mmol nitrate; they then provided (a) blood samples for plasma nitrate and nitrite analysis and (b) saliva samples for 16S rRNA sequencing of the oral microbiome. The LCHF diet (n = 13) reduced oral bacterial diversity and changed the relative abundance of the genera Neisseria (+10%), Fusobacteria (+3%), Prevotella (-9%), and Veillonella (-4%), with no significant changes observed following the HCHO diet (n = 11). Following beetroot juice ingestion, plasma nitrite concentrations were higher for the LCHF diet compared to the HCHO diet (p = 0.04). However, the absence of an interaction with the trial (pre-post) (p = 0.71) suggests that this difference was not due to the dietary intervention. In summary, we found an increase in plasma nitrate and nitrite concentrations in response to nitrate supplementation independent of diet. This suggests the oral microbiome is adaptive to dietary changes and can maintain a nitrate reduction capacity despite a decrease in bacterial diversity following the LCHF diet.
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Beta vulgaris , Microbiota , Humanos , Masculino , Nitritos , Dieta Hiperlipídica , Nitratos , RNA Ribossômico 16S , Bactérias/genética , Carboidratos , Suplementos NutricionaisRESUMO
IgG4-related disease (IgG4-RD) is a new clinical entity characterized by lymphoplasmacytic lesions rich in IgG4-positive plasma cells. Myocardial involvement is extremely rare and not a typical cardiovascular manifestation of IgG4-RD. We report a rare case of IgG4-RD-associated myocardial mass causing severe aortic incompetence, successfully treated with surgery and corticosteroids. (Level of Difficulty: Intermediate.).