RESUMEN
BACKGROUND: ChatGPT was not intended for use in health care, but it has potential benefits that depend on end-user understanding and acceptability, which is where health care students become crucial. There is still a limited amount of research in this area. OBJECTIVE: The primary aim of our study was to assess the frequency of ChatGPT use, the perceived level of knowledge, the perceived risks associated with its use, and the ethical issues, as well as attitudes toward the use of ChatGPT in the context of education in the field of health. In addition, we aimed to examine whether there were differences across groups based on demographic variables. The second part of the study aimed to assess the association between the frequency of use, the level of perceived knowledge, the level of risk perception, and the level of perception of ethics as predictive factors for participants' attitudes toward the use of ChatGPT. METHODS: A cross-sectional survey was conducted from May to June 2023 encompassing students of medicine, nursing, dentistry, nutrition, and laboratory science across the Americas. The study used descriptive analysis, chi-square tests, and ANOVA to assess statistical significance across different categories. The study used several ordinal logistic regression models to analyze the impact of predictive factors (frequency of use, perception of knowledge, perception of risk, and ethics perception scores) on attitude as the dependent variable. The models were adjusted for gender, institution type, major, and country. Stata was used to conduct all the analyses. RESULTS: Of 2661 health care students, 42.99% (n=1144) were unaware of ChatGPT. The median score of knowledge was "minimal" (median 2.00, IQR 1.00-3.00). Most respondents (median 2.61, IQR 2.11-3.11) regarded ChatGPT as neither ethical nor unethical. Most participants (median 3.89, IQR 3.44-4.34) "somewhat agreed" that ChatGPT (1) benefits health care settings, (2) provides trustworthy data, (3) is a helpful tool for clinical and educational medical information access, and (4) makes the work easier. In total, 70% (7/10) of people used it for homework. As the perceived knowledge of ChatGPT increased, there was a stronger tendency with regard to having a favorable attitude toward ChatGPT. Higher ethical consideration perception ratings increased the likelihood of considering ChatGPT as a source of trustworthy health care information (odds ratio [OR] 1.620, 95% CI 1.498-1.752), beneficial in medical issues (OR 1.495, 95% CI 1.452-1.539), and useful for medical literature (OR 1.494, 95% CI 1.426-1.564; P<.001 for all results). CONCLUSIONS: Over 40% of American health care students (1144/2661, 42.99%) were unaware of ChatGPT despite its extensive use in the health field. Our data revealed the positive attitudes toward ChatGPT and the desire to learn more about it. Medical educators must explore how chatbots may be included in undergraduate health care education programs.
Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Humanos , Estudios Transversales , Femenino , Masculino , Adulto , Encuestas y Cuestionarios , Estudiantes del Área de la Salud/psicología , Estudiantes del Área de la Salud/estadística & datos numéricos , Actitud del Personal de Salud , Adulto Joven , Estudiantes de Medicina/psicología , Estudiantes de Medicina/estadística & datos numéricosRESUMEN
BACKGROUND: Myonectin is a myokine with potential effects on the lipid metabolism; however, its regulation by exercise in humans remains unclear. We aimed to compare the efficacy of high-intensity interval training low-volume (HIIT) versus moderate-intensity continuous training (MICT) on serum myonectin, serum lipids, appendicular fat and lean mass, and intramuscular lipids in humans. METHODS: Secondary analysis of a controlled, randomized, clinical trial in adults of both sexes with metabolic syndrome, who underwent a supervised, three-times/week, 12-week treadmill program. HIIT (n = 29) consisted of six intervals with one-minute, high-intensity phases at 90% of peak oxygen consumption (VO2peak) for a total of 22 min. MICT (n = 31) trained at 60% of VO2peak for 36 min. Serum myonectin was measured using a human enzyme-linked immunosorbent assay. Lipid profile was determined by enzymatic methods and free fatty acids (FFA) were measured by gas chromatography. Fat and lean mass were assessed by dual-energy X-ray absorptiometry. Intramuscular lipids were measured through proton magnetic resonance spectroscopy. RESULTS: Subjects had a mean age of 50.8±6.0 years and body mass index of 30.6±4.0 kg/m2. Compared to MICT, HIIT was not superior at increasing serum myonectin (p = 0.661) or linoleic acid (p = 0.263), reducing palmitic (p = 0.286) or stearic acid (p = 0.350), or improving lipid profile (all p>0.05), appendicular fat mass index -AFMI- (p = 0.713) or appendicular lean mass percentage -ALM- (p = 0.810). Compared to baseline, only HIIT significantly increased myonectin (p = 0.042), with a large effect size, although both interventions reduced AFMI and increased ALM with a large effect size. Lipid profile, FFA and intramuscular lipids did not change in any intervention group (p>0.05). CONCLUSIONS: Compared to MICT, HIIT low volume did not demonstrate superiority in improving serum lipids. The fact that both training types reduced AFMI without paralleled significant changes in serum myonectin suggests that this myokine may have a minor effect on short-middle-term exercise-induced fat mobilization.
Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Lípidos , Síndrome Metabólico , Humanos , Síndrome Metabólico/sangre , Síndrome Metabólico/terapia , Masculino , Femenino , Entrenamiento de Intervalos de Alta Intensidad/métodos , Persona de Mediana Edad , Lípidos/sangre , Adulto , Fibronectinas/sangre , Metabolismo de los Lípidos , Consumo de Oxígeno , Ejercicio Físico/fisiologíaRESUMEN
INTRODUCTION: Heart rate variability (HRV), brain resting-state functional connectivity (rsFC), and gut microbiota (GM) are three recognized indicators of health status, whose relationship has not been characterized. We aimed to identify the GM genera and families related to HRV and rsFC, the interaction effect of HRV and rsFC on GM taxa abundance, and the mediation effect of diet on these relationships. METHODS: Eighty-eight healthy, young Colombian men were included in this cross-sectional study. HRV metrics were extracted from 24-hour Holter monitoring data and the resting functional connectivity strength (FCS) of 15 networks were derived from functional magnetic resonance imaging. Gut microbiota composition was assessed using the sequences of the V3-V4 regions of the 16â¯S rRNA gene, and diet was evaluated using a food frequency questionnaire. Multivariate linear regression analyses were performed to evaluate the correlations between the independent variables (HRV metrics and FCS) and the dependent variables (GM taxa abundance or alpha diversity indexes). Mediation analyses were used to test the role of diet in the relationship between HRV and GM. RESULTS: The sympathovagal quotient (SQ) and the FCS of control networks were positively correlated with the abundance of the gut Ruminococcaceae family and an unclassified Ruminococcaceae genus (Ruminococcaceae_unc). Additionally, the interaction between the FCS of the control network and SQ reduced the individual main effects on the Ruminococcaceae_unc abundance. Finally, reduced habitual fiber intake partially mediated the relationship between SQ and this genus. CONCLUSION: Two indicators of self-regulation, HRV and the rsFC of control networks, are related to the abundance of gut microbiota taxa in healthy men. However, only HRV is related to habitual dietary intake; thus, HRV could serve as a marker of food choice and GM composition in the future.
Asunto(s)
Encéfalo , Microbioma Gastrointestinal , Masculino , Humanos , Estudios Transversales , Dieta , Ingestión de AlimentosRESUMEN
Skeletal muscle fibers obtained by enzymatic dissociation of mouse muscles are a useful model for physiological experiments. However, most papers deal with the short fibers of the flexor digitorum brevis (FDB), which restrains the scope of results dealing with fiber types, limits the amount of biological material available, and impedes a clear connection between cellular physiological phenomena and previous biochemical and dynamical knowledge obtained in other muscles. This paper describes how to obtain intact fibers from six muscles with different fiber type profiles and lengths. Using C57BL/6 adult mice, we show the muscle dissection and fiber isolation protocol and demonstrate the suitability of the fibers for Ca2+ transient studies and their morphometric characterization. The fiber type composition of the muscles is also presented. When dissociated, all muscles rendered intact, living fibers that contract briskly for more than 24 h. FDB gave short (<1 mm), peroneus digiti quarti (PDQA) and peroneus longus (PL) gave intermediate (1-3 mm), while extensor digitorum longus (EDL), extensor hallucis longus (EHL), and soleus muscles released long (3-6 mm) fibers. When recorded with the fast dye Mag-Fluo-4, Ca2+ transients of PDQA, PL, and EHL fibers showed the fast, narrow kinetics reminiscent of the morphology type II (MT-II), known to correspond to type IIX and IIB fibers. This is consistent with the fact that these muscles have over 90% of type II fibers compared with FDB (~80%) and soleus (~65%). Moving beyond FDB, we demonstrate for the first time the dissociation of several muscles, which render fibers spanning a range of lengths between 1 and 6 mm. These fibers are viable and give fast Ca2+ transients, indicating that the MT-II can be generalized to IIX and IIB fast fibers, regardless of their muscle source. These results increase the availability of models for mature skeletal muscle studies.
Asunto(s)
Extremidad Inferior , Músculo Esquelético , Animales , Ratones , Ratones Endogámicos C57BL , Fibras Musculares Esqueléticas , Miembro PosteriorRESUMEN
BACKGROUND: Small airways disease (SAD), a novel finding described in post-acute COVID-19 patients, should be suspected when respiratory symptoms continue, air trapping persists on expiratory CT scans, and imaging findings fail to improve despite objectively better conventional pulmonary function test (PFT) parameters. The forced oscillation technique (FOT) and Multiple breathing washout (MBW) are both very sensitive methods for detecting anomalies in the peripheral airways. CASE PRESENTATION: We discuss the case of a 60-year-old Hispanic patient who had severe COVID-19 pneumonia and developed dyspnea, fatigue, and limited daily activity a year later. The PFTs revealed restrictive lung disease, as seen by significant diffusing capacity of the lungs for carbon monoxide (DLCO) decrease, severe desaturation, and poor 6-min walk test (6MWT) performance. The patient was treated with lowering corticosteroids as well as pulmonary rehabilitation (PR). During the 24-month follow-up, the dyspnea and fatigue persisted. On PFTs, 6MWT performance and restricted pattern improved slightly, but MBW discovered significant ventilatory inhomogeneity. FOT revealed substantial peripheral airway obstructive abnormalities. On CT scans, air trapping and ground-glass opacities (GGO) improved somewhat. The patient used a bronchodilator twice a day and low-dose inhaled corticosteroids (160 µg of budesonide and 4.5 µg of formoterol fumarate dihydrate) for nine months. PR sessions were resuming. The restricting parameters were stabilized and the DLCO had normalized after 36 months, with a 6MWT performance of 87% but significant desaturation. The CT scan revealed traction bronchiectasis, low GGO, and persistent air trapping. Without normalization, FOT and MBW scores improved, indicating small airway disease. CONCLUSIONS: The necessity of integrating these tests when detecting SAD is emphasized in our paper. This article lays the foundation for future research into the best ways to manage and monitor SAD in post-acute COVID-19 patients.
Asunto(s)
Asma , COVID-19 , Humanos , Persona de Mediana Edad , Síndrome Post Agudo de COVID-19 , Estudios de Seguimiento , Disnea/etiología , FatigaRESUMEN
Physical membrane models permit to study and quantify the interactions of many external molecules with monitored and simplified systems. In this work, we have constructed artificial Langmuir single-lipid monolayers with dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylethanolamine (DPPE), dipalmitoylphosphatidylserine (DPPS), or sphingomyelin to resemble the main lipid components of the mammalian cell membranes. We determined the collapse pressure, minimum area per molecule, and maximum compression modulus (Cs-1) from surface pressure measurements in a Langmuir trough. Also, from compression/expansion isotherms, we estimated the viscoelastic properties of the monolayers. With this model, we explored the membrane molecular mechanism of toxicity of the well-known anticancer drug doxorubicin, with particular emphasis in cardiotoxicity. The results showed that doxorubicin intercalates mainly between DPPS and sphingomyelin, and less between DPPE, inducing a change in the Cs-1 of up to 34% for DPPS. The isotherm experiments suggested that doxorubicin had little effect on DPPC, partially solubilized DPPS lipids toward the bulk of the subphase, and caused a slight or large expansion in the DPPE and sphingomyelin monolayers, respectively. Furthermore, the dynamic viscoelasticity of the DPPE and DPPS membranes was greatly reduced (by 43 and 23%, respectively), while the reduction amounted only to 12% for sphingomyelin and DPPC models. In conclusion, doxorubicin intercalates into the DPPS, DPPE, and sphingomyelin, but not into the DPPC, membrane lipids, inducing a structural distortion that leads to decreased membrane stiffness and reduced compressibility modulus. These alterations may constitute a novel, early step in explaining the doxorubicin mechanism of action in mammalian cancer cells or its toxicity in non-cancer cells, with relevance to explain its cardiotoxicity.
Asunto(s)
Cardiotoxicidad , Esfingomielinas , Animales , Humanos , 1,2-Dipalmitoilfosfatidilcolina/química , Doxorrubicina/farmacología , Membrana Celular/química , Propiedades de Superficie , MamíferosRESUMEN
Myonectin has shown beneficial effects on lipid regulation in murine models; therefore, it may have implications in the pathophysiology of metabolic syndrome (MS). We evaluated the relationship between serum myonectin and serum lipids, global and regional fat mass, intramuscular lipid content, and insulin resistance (IR) in adults with metabolic risk factors. This was a cross-sectional study in sedentary adults who were diagnosed with MS or without MS (NMS). Serum myonectin was quantified by enzyme-linked immunosorbent assay, lipid profile by conventional techniques, and free fatty acids (FFA) by gas chromatography. Body composition was assessed by dual-energy X-ray absorptiometry and intramuscular lipid content through proton nuclear magnetic resonance spectroscopy in the right vastus lateralis muscle. IR was estimated with the homeostatic model assessment (HOMA-IR). The MS (n = 61) and NMS (n = 29) groups were comparable in age (median (interquartile range): 51.0 (46.0-56.0) vs. 53.0 (45.5-57.5) years, p > 0.05) and sex (70.5% men vs. 72.4% women). MS subjects had lower serum levels of myonectin than NMS subjects (1.08 (0.87-1.35) vs. 1.09 (0.93-4.05) ng·mL-1, p < 0.05). Multiple linear regression models adjusted for age, sex, fat mass index and lean mass index showed that serum myonectin was negatively correlated with the android/gynoid fat mass ratio (R2 = 0.48, p < 0.01), but not with the lipid profile, FFA, intramuscular lipid content or HOMA-IR. In conclusion, serum myonectin is lower in subjects with MS. Myonectin negatively correlates with a component relevant to the pathophysiology of MS, such as the android/gynoid fat mass ratio, but not with other components such as FFA, intramuscular fat or IR.
Asunto(s)
Resistencia a la Insulina , Síndrome Metabólico , Masculino , Humanos , Adulto , Femenino , Animales , Ratones , Síndrome Metabólico/metabolismo , Obesidad/metabolismo , Estudios Transversales , Resistencia a la Insulina/fisiología , Ácidos Grasos no EsterificadosRESUMEN
AIMS: Animal models are essential to investigate cardiovascular pathophysiology and pharmacology, but phylogenetic diversity makes it necessary to identify the model with vasculature most similar to that of humans. METHODS AND RESULTS: In this study, we compared the mesenteric arteries of humans, pigs, rabbits and rats in terms of the i) evolutionary changes in the amino acid sequences of α1 and ß2 adrenoceptors; M1, M2, and M3 muscarinic receptors; and bradykinin (BKR) and thromboxane-prostanoid (TP) receptors, through bioinformatics tools; ii) expression of α1, ß2, M1, M3 and TP receptors in each tunica, as assessed by immunofluorescence; and iii) reactivity to receptor-dependent and independent contractile agonists and relaxants, by performing organ bath assays. Phylogenetically, pigs showed the highest degree of evolutionary closeness to humans for all receptors, and with the exception of BKR, rabbits presented the greatest evolutionary difference compared to humans, pigs and rats. The expression of the measured receptors in the three vascular tunica in pigs was most similar to that in humans. Using a one-way ANOVA to determine the differences in vascular reactivity, we found that the reactivity of pigs was the most similar to that of humans in terms of sensitivity (pD2) and maximum effect of vascular reactivity (Emax) to KCl, phenylephrine, isoproterenol and carbachol. CONCLUSIONS: The pig is a better vascular model than the rabbit or rat to extrapolate results to human mesenteric arteries. Comparative vascular studies have implications for understanding the evolutionary history of different species. TRANSLATIONAL PERSPECTIVE: The presented findings are useful for identifying an animal model with a vasculature that is similar to that of humans. This information is important to extrapolate, with greater precision, the findings in arterial pathophysiology or pharmacology from animal models to the healthy or diseased human being.
Asunto(s)
Arterias Mesentéricas , Contracción Muscular , Humanos , Ratas , Conejos , Animales , Porcinos , Filogenia , Fenilefrina/farmacología , Receptores Muscarínicos/metabolismo , Prostaglandinas/metabolismoRESUMEN
Given their importance in predicting clinical outcomes, cardiorespiratory fitness (CRF) and muscle status can be considered new vital signs. However, they are not routinely evaluated in healthcare settings. Here, we present a comprehensive review of the epidemiological, mechanistic, and practical bases of the evaluation of CRF and muscle status in adults in primary healthcare settings. We highlight the importance of CRF and muscle status as predictors of morbidity and mortality, focusing on their association with cardiovascular and metabolic outcomes. Notably, adults in the best quartile of CRF and muscle status have as low as one-fourth the risk of developing some of the most common chronic metabolic and cardiovascular diseases than those in the poorest quartile. The physiological mechanisms that underlie these epidemiological associations are addressed. These mechanisms include the fact that both CRF and muscle status reflect an integrative response to the body function. Indeed, muscle plays an active role in the development of many diseases by regulating the body's metabolic rate and releasing myokines, which modulate metabolic and cardiovascular functions. We also go over the most relevant techniques for assessing peak oxygen uptake as a surrogate of CRF and muscle strength, mass, and quality as surrogates of muscle status in adults. Finally, a clinical case of a middle-aged adult is discussed to integrate and summarize the practical aspects of the information presented throughout. Their clinical importance, the ease with which we can assess CRF and muscle status using affordable techniques, and the availability of reference values, justify their routine evaluation in adults across primary healthcare settings.
Asunto(s)
Capacidad Cardiovascular , Enfermedades Cardiovasculares , Adulto , Humanos , Persona de Mediana Edad , Capacidad Cardiovascular/fisiología , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/diagnóstico , Prueba de Esfuerzo/métodos , Fuerza Muscular , Músculos , Aptitud Física/fisiologíaRESUMEN
OBJECTIVE: To standardize a method for 1H MRS intramuscular absolute quantification of carnosine in the thigh, using a surface coil and water as internal reference. MATERIALS AND METHODS: Carnosine spectra were acquired in phantoms (5, 10, and 15 mM) as well as in the right gastrocnemius medialis (GM) and right vastus lateralis (VLM) muscles of young team sports athletes, using volume (VC) and surface (SC) coils on a 3 T scanner, with the same receiver gain. Water spectra were used as internal reference for the absolute quantification of carnosine. RESULTS: Phantom's experiments showed a maximum error of 7%, highlighting the validity of the measurements in the study setup. The carnosine concentrations (mmol/kg ww, mean ± SD) measured in the GM were 6.8 ± 2.2 with the VC (CcarVC) and 10.2 ± 3.0 with the SC (CcarSC) (P = 0.013; n = 9). Therefore, a correction was applied to these measurements (CcarVC = 0.6582*CcarSC), to make coils performance comparable (6.8 ± 2.2 for VC and 6.7 ± 2.0 for SC, P = 0.97). After that, only the SC was used to quantify carnosine in the VLM, where a concentration of 5.4 ± 1.5 (n = 30) was found, with significant differences between men (6.2 ± 1.3; n = 15) and women (4.6 ± 1.2; n = 15). The error in quantitation was 5.3-5.5% with both coils. CONCLUSION: The method using the SC and water as internal reference can be used to quantify carnosine in voluminous muscles and regions of the body in humans, where the VC is not suitable, such as the VLM.
Asunto(s)
Carnosina , Masculino , Humanos , Femenino , Músculo Cuádriceps/diagnóstico por imagen , Agua , Músculo Esquelético/diagnóstico por imagen , MusloRESUMEN
The excitation-contraction coupling (ECC) in skeletal muscle refers to the Ca2+-mediated link between the membrane excitation and the mechanical contraction. The initiation and propagation of an action potential through the membranous system of the sarcolemma and the tubular network lead to the activation of the Ca2+-release units (CRU): tightly coupled dihydropyridine and ryanodine (RyR) receptors. The RyR gating allows a rapid, massive, and highly regulated release of Ca2+ from the sarcoplasmic reticulum (SR). The release from triadic places generates a sarcomeric gradient of Ca2+ concentrations ([Ca2+]) depending on the distance of a subcellular region from the CRU. Upon release, the diffusing Ca2+ has multiple fates: binds to troponin C thus activating the contractile machinery, binds to classical sarcoplasmic Ca2+ buffers such as parvalbumin, adenosine triphosphate and, experimentally, fluorescent dyes, enters the mitochondria and the SR, or is recycled through the Na+/Ca2+ exchanger and store-operated Ca2+ entry (SOCE) mechanisms. To commemorate the 7th decade after being coined, we comprehensively and critically reviewed "old", historical landmarks and well-established concepts, and blended them with recent advances to have a complete, quantitative-focused landscape of the ECC. We discuss the: 1) elucidation of the CRU structures at near-atomic resolution and its implications for functional coupling; 2) reliable quantification of peak sarcoplasmic [Ca2+] using fast, low affinity Ca2+ dyes and the relative contributions of the Ca2+-binding mechanisms to the whole concert of Ca2+ fluxes inside the fibre; 3) articulation of this novel quantitative information with the unveiled structural details of the molecular machinery involved in mitochondrial Ca2+ handing to understand how and how much Ca2+ enters the mitochondria; 4) presence of the SOCE machinery and its different modes of activation, which awaits understanding of its magnitude and relevance in situ; 5) pharmacology of the ECC, and 6) emerging topics such as the use and potential applications of super-resolution and induced pluripotent stem cells (iPSC) in ECC. Blending the old with the new works better!
RESUMEN
Spider venoms constitute a trove of novel peptides with biotechnological interest. Paucity of next-generation-sequencing (NGS) data generation has led to a description of less than 1% of these peptides. Increasing evidence supports the underestimation of the assembled genes a single transcriptome assembler can predict. Here, the transcriptome of the venom gland of the spider Pamphobeteus verdolaga was re-assembled, using three free access algorithms, Trinity, SOAPdenovo-Trans, and SPAdes, to obtain a more complete annotation. Assembler's performance was evaluated by contig number, N50, read representation on the assembly, and BUSCO's terms retrieval against the arthropod dataset. Out of all the assembled sequences with all software, 39.26% were common between the three assemblers, and 27.88% were uniquely assembled by Trinity, while 27.65% were uniquely assembled by SPAdes. The non-redundant merging of all three assemblies' output permitted the annotation of 9232 sequences, which was 23% more when compared to each software and 28% more when compared to the previous P. verdolaga annotation; moreover, the description of 65 novel theraphotoxins was possible. In the generation of data for non-model organisms, as well as in the search for novel peptides with biotechnological interest, it is highly recommended to employ at least two different transcriptome assemblers.
Asunto(s)
Venenos de Araña , Transcriptoma , Perfilación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Péptidos/genética , Programas Informáticos , Venenos de Araña/química , Venenos de Araña/genéticaRESUMEN
Background: Despite the growing concerns related to the potential of long-term pulmonary sequelae due to COVID-19, data about intermediate and long-term changes in the respiratory function of patients who recover is relatively sparse, particularly in developing countries. Objectives: To assess the characteristics and pulmonary function at follow-up in a sample of Ecuadorian patients that recovered from the virus. Methods: We conducted a cross-sectional study that included 43 patients after symptomatic COVID infection, who were evaluated by spirometry, single breath DLCO, and 6MWT. For statistical analysis we performed point biserial correlations, and chi squared tests. Results: Overall, 30.3% of patients (n = 13) reported persistent symptoms, with fatigue being the most common (23.3%, n = 10). Around 34.9% (n = 15) of the sample had a restrictive spirometry pattern, 18.6% (n = 8) had an abnormally decreased adjusted DLCO. A restrictive spirometry pattern was associated with an abnormally low adjusted DLCO (χ2(2) = 11,979, p = 0.001). Conclusion: We found that a considerable proportion of patients presented with persistent symptoms and alterations in pulmonary function following COVID-19, mainly a restrictive respiratory pattern and abnormally low DLCO. Further studies are needed to determine which patients may benefit from the follow-up with specific pulmonary function tests.
RESUMEN
OBJECTIVE: The aim of the study was to evaluate the safety of high-intensity, low-volume interval training (HIIT-low volume) compared with moderate-intensity continuous aerobic training (MICT) in adults with metabolic syndrome. METHODS: This is a controlled, randomized, clinical trial in patients without history of ischemic heart disease or diabetes, who underwent a supervised, 3 sessions/week, 12-week treadmill exercise program. The HIIT-low volume (n = 29) sessions consisted of 6 intervals with 1-minute, high-intensity phases at 90% of peak oxygen consumption (VO2peak). The MICT (n = 31) trained at 60% of VO2peak for 30 minutes. A new approach to record and classify all clinical events according to possible causality based on Naranjo's algorithm was developed. RESULTS: Patients were 50.8 ± 6.0 years old, 70% women, with body mass index of 30.6 ± 4.0 kg/m2 and VO2peak of 29.0 ± 6.3 mL·kg-1·min-1. In total, 60 clinical events were recorded in the HIIT-low volume group and 48 in the MICT group, with 59.3% classified as general disease. Only 21 events were classified as adverse reactions possibly related to exercise, without any serious adverse reactions. Both interventions had a similar incidence of musculoskeletal events (incidence rate ratio, 1.1; 95% confidence interval, 0.6-1.8), but HIIT-low volume had a higher incidence of cardiovascular events (incidence rate ratio, 2.9; 95% CI, 0.4-22.8) after adjusting for age, sex, and body mass index (HIIT-low volume: chest pain [n = 1] and symptoms of venous insufficiency of lower limbs [n = 2]; MICT: chest pain [n = 1]). CONCLUSIONS: The HIIT-low volume and MICT are safe in patients with metabolic syndrome. We recommend a muscle-conditioning program prior to both and to avoid HIIT-low volume in treadmill in patients with venous insufficiency of the lower limbs.Trial registration number NCT03087721.
Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Síndrome Metabólico , Insuficiencia Venosa , Adulto , Dolor en el Pecho , Femenino , Humanos , Masculino , Síndrome Metabólico/epidemiología , Síndrome Metabólico/terapia , Persona de Mediana EdadRESUMEN
PURPOSE: We carried out a randomized, clinical trial in adults of both sexes with metabolic syndrome (MS) to assess the efficacy of high-intensity, low-volume interval training (HIIT) compared to moderate-intensity continuous training (MICT) on insulin resistance (IR), muscle mass, muscle activation, and serum musclin. METHODS: Fasting glycemia, insulinemia, and glycated haemoglobin were determined by conventional methods, IR by Homeostatic model assessment (HOMA), lean mass by Dual-Energy X-ray Absorptiometry, muscle activation through carnosine by Proton Magnetic Resonance Spectroscopy, and musclin by Enzyme-Linked ImmunoSorbent Assay before and after a supervised, three-times/week, 12-week treadmill programme. HIIT (n = 29) consisted of six intervals with one-minute, high-intensity phases at 90% of peak oxygen consumption (VO2peak). MICT (n = 31) trained at 60% of VO2peak for 30 min. RESULTS: Patients had a mean age of 50.8 ± 6.0 years, body mass index of 30.6 ± 4.0 kg/m2, and VO2peak of 29.0 ± 6.3 mL.kg-1.min-1. Compared to MICT, HIIT was not superior at reducing Ln HOMA-IR (adjusted mean difference: 0.083 [95%CI - 0.092 to 0.257]), carnosine or musclin or at increasing thigh lean mass. HIIT increased carnosine by 0.66 mmol/kg.ww (95% CI 0.08-1.24) after intervention. Both interventions reduced IR, body fat percentage and increased total lean mass/height2 and VO2peak. Musclin showed a non-significant reduction with a small effect size after both interventions. CONCLUSION: Compared to MICT, HIIT is not superior at reducing IR, carnosine or musclin or at increasing skeletal muscle mass in adults with MS. Both training types improved IR, muscle mass and body composition. NCT03087721, March 22nd, 2017. TRIAL REGISTRATION NUMBER: NCT03087721. Registered March 22nd, 2017.
Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Resistencia a la Insulina/fisiología , Síndrome Metabólico/prevención & control , Síndrome Metabólico/fisiopatología , Adulto , Biomarcadores/sangre , Carnosina/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Musculares/sangre , Factores de Transcripción/sangreRESUMEN
OBJECTIVE: The aim of this study was to compare the effects of low-volume, high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on body composition in adults with metabolic syndrome (MS). METHODS: This is a post hoc analysis of the randomized clinical trial Intraining-MET. Sixty adults (40-60 years old) were randomized to an MICT (n = 31) or HIIT (n = 29) supervised programme 3 days/week for 12 weeks. MICT sessions were conducted for 36 min at 60% of peak oxygen consumption (VO2peak). HIIT sessions included 6 intervals at 90% VO2peak for 1 min, followed by 2 min at 50% VO2peak. Body composition was assessed with dual energy X-ray absorptiometry. RESULTS: Body weight did not change from pre- to post-training in either MICT (78.9 ± 15.6 kg; 77.7 ± 16.5 kg, p = 0.280) or HIIT groups (76.3 ± 13.4 kg; 76.3 ± 13.7 kg, p = 0.964). Body fat percentage and fat mass (FM) decreased post-training in the MICT (-0.9%; 95% confidence interval [CI]: -0.27 to -1.47 and -0.7 kg; 95% CI: -0.12 to -1.30) and HIIT groups (-1.0%; 95% CI: -0.32 to -1.68 and -0.8 kg; 95% CI: -0.17 to -1.47). Compared to the HIIT programme, MICT significantly reduced android FM (-0.14 kg; 95% CI: -0.02 to -0.26). Lean mass (LM) increased post-training in MICT (+0.7 kg; 95% CI: 0.01-1.41) and HIIT groups (+0.9 kg; 95% CI: 0.12-1.64), but only HIIT increased the trunk LM (+0.6 kg; 95% CI: 0.06-1.20). CONCLUSIONS: Both MICT and HIIT reduced FM without changing body weight in adults with MS. MICT had additional benefits by reducing the android FM, whereas HIIT seemed to increase LM. Given the characteristics of the post hoc analysis, further research is required to confirm these results.
Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Síndrome Metabólico , Adulto , Composición Corporal , Entrenamiento de Intervalos de Alta Intensidad/métodos , Humanos , Síndrome Metabólico/terapia , Persona de Mediana EdadRESUMEN
Mag-Fluo-4 has revealed differences in the kinetics of the Ca2+ transients of mammalian fiber types (I, IIA, IIX, and IIB). We simulated the changes in [Ca2+] through the sarcomere of these four fiber types, considering classical (troponin -Tn-, parvalbumin -Pv-, adenosine triphosphate -ATP-, sarcoplasmic reticulum Ca2+ pump -SERCA-, and dye) and new (mitochondria -MITO-, Na+/Ca2+ exchanger -NCX-, and store-operated calcium entry -SOCE-) Ca2+ binding sites, during single and tetanic stimulation. We found that during a single twitch, the sarcoplasmic peak [Ca2+] for fibers type IIB and IIX was around 16 µM, and for fibers type I and IIA reached 10-13 µM. The release rate in fibers type I, IIA, IIX, and IIB was 64.8, 153.6, 238.8, and 244.5 µM ms-1, respectively. Both the pattern of change and the peak concentrations of the Ca2+-bound species in the sarcoplasm (Tn, PV, ATP, and dye), the sarcolemma (NCX, SOCE), and the SR (SERCA) showed the order IIB ≥ IIX > IIA > I. The capacity of the NCX was 2.5, 1.3, 0.9, and 0.8% of the capacity of SERCA, for fibers type I, IIA, IIX, and IIB, respectively. MITO peak [Ca2+] ranged from 0.93 to 0.23 µM, in fibers type I and IIB, respectively, while intermediate values were obtained in fibers IIA and IIX. The latter numbers doubled during tetanic stimulation. In conclusion, we presented a comprehensive mathematical model of the excitation-contraction coupling that integrated most classical and novel Ca2+ handling mechanisms, overcoming the limitations of the fast- vs. slow-fibers dichotomy and the use of slow dyes.
Asunto(s)
Calcio/metabolismo , Acoplamiento Excitación-Contracción/fisiología , Modelos Teóricos , Fibras Musculares de Contracción Rápida/metabolismo , Fibras Musculares de Contracción Lenta/metabolismo , Sarcómeros/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Simulación por Computador , Cinética , Ratones , Mitocondrias/metabolismo , Parvalbúminas/metabolismo , Retículo Sarcoplasmático/metabolismo , Troponina/metabolismoRESUMEN
BACKGROUND: We studied whether musclin function in humans is related to glycemic control, body composition, and cardiorespiratory capacity. METHODS: A cross-sectional study was performed in sedentary adults with or without metabolic syndrome (MS). Serum musclin was measured by enzyme-linked immunosorbent assay. Insulin resistance (IR) was evaluated by the homeostatic model assessment (HOMA-IR). Body composition was determined by dual-energy X-ray absorptiometry and muscle composition by measuring carnosine in the thigh, a surrogate of fiber types, through proton magnetic resonance spectroscopy. Cardiorespiratory capacity was assessed through direct ergospirometry. RESULTS: The control (n=29) and MS (n=61) groups were comparable in age (51.5±6.5 years old vs. 50.7±6.1 years old), sex (72.4% vs. 70.5% women), total lean mass (58.5%±7.4% vs. 57.3%±6.8%), and peak oxygen consumption (VO2peak) (31.0±5.8 mL O2./kg.min vs. 29.2±6.3 mL O2/kg.min). Individuals with MS had higher body mass index (BMI) (30.6±4.0 kg/m2 vs. 27.4± 3.6 kg/m2), HOMA-IR (3.5 [95% confidence interval, CI, 2.9 to 4.6] vs. 1.7 [95% CI, 1.1 to 2.0]), and musclin (206.7 pg/mL [95% CI, 122.7 to 387.8] vs. 111.1 pg/mL [95% CI, 63.2 to 218.5]) values than controls (PË0.05). Musclin showed a significant relationship with HOMA-IR (ß=0.23; 95% CI, 0.12 to 0.33; PË0.01), but not with VO2peak, in multiple linear regression models adjusted for age, sex, fat mass, lean mass, and physical activity. Musclin was significantly associated with insulin, glycemia, visceral fat, and regional muscle mass, but not with BMI, VCO2peak, maximum heart rate, maximum time of work, or carnosine. CONCLUSION: In humans, musclin positively correlates with insulinemia, IR, and a body composition profile with high visceral adiposity and lean mass, but low body fat percentage. Musclin is not related to BMI or cardiorespiratory capacity.