Respiratory Physiology & Neurobiology最新文献

{"title":"A short duration of mechanical ventilation alters redox status in the diaphragm and aggravates inflammation in septic mice","authors":"Pedro Alves Machado-Junior ,&nbsp;Marcelo Santiago Soares Dias ,&nbsp;Ana Beatriz Farias de Souza ,&nbsp;Leonardo Spinelli Estevão Lopes ,&nbsp;Tatiana Prata Menezes ,&nbsp;André Talvani ,&nbsp;Laurent Brochard ,&nbsp;Frank Silva Bezerra","doi":"10.1016/j.resp.2024.104361","DOIUrl":"10.1016/j.resp.2024.104361","url":null,"abstract":"<div><h3>Background</h3><div>Mechanical ventilation (MV) is a life support method used to treat patients with respiratory failure. High tidal volumes during MV can cause ventilator-induced lung injury (VILI), but also affect other organs, such as the diaphragm (Dia) causing ventilator-induced diaphragmatic dysfunction (VIDD). VIDD is often associated with a complicated course on MV. Sepsis can induce inflammation and oxidative stress, contributing to the impairment of the Dia and worsening of the prognosis. This study evaluated the additive or synergistic effects of a short course of mechanical ventilation on Dia in healthy and septic adult mice.</div></div><div><h3>Methods</h3><div>32 adult male C57BL/6 mice were randomly into four groups: Control (CG), non-ventilated animals instilled with saline solution (PBS1x); Lipopolysaccharide (LPS), non-ventilated animals instilled with PBS solution containing lipopolysaccharide; Mechanical Ventilation (MV) for 1 h, ventilated animals instilled with PBS solution; and Mechanical Ventilation and LPS (MV+LPS), ventilated animals instilled with PBS solution containing LPS. At the end of the experimental protocol, the animals were euthanized, then blood and diaphragm tissue samples were collected.</div></div><div><h3>Results</h3><div>Evaluation of leukocyte/blood parameters and diaphragm muscle showed that MV, LPS and the combination of both were able to increase neutrophil count, creatine kinase, inflammatory mediators and oxidative stress in all groups compared to the control. MV and sepsis combined had additive effects on inflammation and lipid peroxidation.</div></div><div><h3>Conclusions</h3><div>A short course of Mechanical ventilation promotes inflammation and oxidative stress and, its combination with sepsis further increases local and systemic inflammation.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104361"},"PeriodicalIF":1.9,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142473463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential neuromotor control of the vertical and longitudinal genioglossus muscle fibers: An overlooked tongue retractor","authors":"Ron Oliven ,&nbsp;Arie Oliven ,&nbsp;Mostafa Somri ,&nbsp;Alan R. Schwartz ,&nbsp;Emilia Hardak","doi":"10.1016/j.resp.2024.104354","DOIUrl":"10.1016/j.resp.2024.104354","url":null,"abstract":"<div><h3>Introduction</h3><div>The genioglossus (GG) is known to be the main tongue protrusor, and therefore plays a major role in breathing. However, due to the fan shape of the GG fibers, it could be assumed that contraction of the anterior fibers of the GG do not cause tongue protrusion. In this study, we examined the effect of contraction of the anterior-vertical fibers of the GG (GG_V) on the tongue and their EMG activity during wakefulness and sleep. The findings were compared to those of the longitudinal fibers (GG_L), which, based on their orientation, are responsible for tongue protrusion.</div></div><div><h3>Methods</h3><div>Fine-wire electrode pairs were placed into the GG_V and GG_L in 11 patients with untreated OSA. Movement of the tongue during electrical stimulation at each site was videoed. The same electrodes were used to record EMG from both sites during respiratory stimulation by inspiratory loading and CO₂ rebreathing during wakefulness. During sleep, repetitive flow limitation events were induced with low-level CPAP to augment GG activity.</div></div><div><h3>Results</h3><div>In all participants, electrical stimulation of GG_L and GG_V protruded and retracted the tongue, respectively. Respiratory stimulation increased GG activity, but GG_V reached only 39 % and 23 % of peak GG_L activity during high resistive loading and PCO₂ of 65 mmHg, respectively. Flow limitation during sleep increased GG_L to levels that were considerably higher than awake baseline, but GG_V activity remained tonic or with minimal phasic activity, reaching on average 15 % of GG_L peak activity.</div></div><div><h3>Conclusions</h3><div>Our electrical stimulation findings indicate that GG_V is a tongue retractor and depressor. Tongue stimulation for OSA should avoid this area. The EMG results demonstrate that the anterior part of the GG is controlled very differently from the longitudinal protrusive fibers. The GG_V responses are similar to those previously found in tongue retractors and peri-pharyngeal muscles other than the GG, in which diminished activation during sleep is likely to be involved in the failure of increasing GG_L activity to alleviate flow limitation.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104354"},"PeriodicalIF":1.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142401119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of sildenafil on gas exchange, ventilatory, and sensory responses to exercise in subjects with mild-to-moderate COPD: A randomized cross-over trial","authors":"Ricardo Gass ,&nbsp;Franciele Plachi ,&nbsp;Fernanda O.B. Silva ,&nbsp;Talmir Nolasco ,&nbsp;Mateus Samuel Tonetto ,&nbsp;Leandro S. Goelzer ,&nbsp;Paulo T. Muller ,&nbsp;Marli M. Knorst ,&nbsp;J. Alberto Neder ,&nbsp;Danilo C. Berton","doi":"10.1016/j.resp.2024.104359","DOIUrl":"10.1016/j.resp.2024.104359","url":null,"abstract":"<div><div>Excess exercise ventilation (high ventilation (V̇_E)/carbon dioxide output (V̇CO₂)) contributes significantly to dyspnea and exercise intolerance since the earlier stages of chronic obstructive pulmonary disease (COPD). A selective pulmonary vasodilator (inhaled nitric oxide) has shown to increase exercise tolerance secondary to lower V̇_E/V̇CO₂ and dyspnea in this patient population. We aimed to assess whether a clinically more practical option - oral sildenafil - would be associated with similar beneficial effects. In a randomized, placebo-controlled study, twenty-four patients with mild-to-moderate COPD completed, on different days, two incremental cardiopulmonary exercise tests (CPET) one hour after sildenafil or placebo. Eleven healthy participants performed a CPET in a non-interventional visit for comparative purposes with patients when receiving placebo. Patients (FEV₁= 69.4 ± 13.5 % predicted) showed higher ventilatory demands (V̇_E/V̇CO₂), worse pulmonary gas exchange, and higher dyspnea during exercise compared to controls (FEV₁= 98.3 ±11.6 % predicted). Contrary to our expectations, however, sildenafil (50 mg; N= 15) did not change exertional V̇_E/V̇CO₂, dead space/tidal volume ratio, operating lung volumes, dyspnea, or exercise tolerance compared to placebo (<em>P</em>&gt;0.05). Due to the lack of significant beneficial effects, nine additional patients were trialed with a higher dose (100 mg). Similarly, active intervention was not associated with positive physiological or sensory effects. In conclusion, acute oral sildenafil (50 or 100 mg) failed to improve gas exchange efficiency or excess exercise ventilation in patients with predominantly moderate COPD. The current study does not endorse a therapeutic role for sildenafil to mitigate exertional dyspnea in this specific patient subpopulation.</div><div>Clinical trial registry: <span><span>https://ensaiosclinicos.gov.br/rg/RBR-4qhkf4</span><svg><path></path></svg></span></div><div>Web of Science Researcher ID: O-7665–2019</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104359"},"PeriodicalIF":1.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142401120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inspiratory muscle training improves autonomic function in myalgic encephalomyelitis/chronic fatigue syndrome and post-acute sequelae of SARS-CoV-2: A pilot study","authors":"Heather Edgell ,&nbsp;Tania J. Pereira ,&nbsp;Kathleen Kerr ,&nbsp;Riina Bray ,&nbsp;Farah Tabassum ,&nbsp;Lauren Sergio ,&nbsp;Smriti Badhwar","doi":"10.1016/j.resp.2024.104360","DOIUrl":"10.1016/j.resp.2024.104360","url":null,"abstract":"<div><div>Post-acute sequelae of SARS-CoV-2 (PASC), or Long COVID, and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are debilitating post-viral conditions with many symptomatic overlaps, including exercise intolerance and autonomic dysfunction. Both conditions are growing in prevalence, and effective safe treatment strategies must be investigated. We hypothesized that inspiratory muscle training (IMT) could be used in PASC and mild to moderate ME/CFS to mitigate symptoms, improve exercise capacity, and improve autonomic function. We recruited healthy controls (n=12; 10 women), people with PASC (n=9; 8 women), and people with mild to moderate ME/CFS (n=12; 10 women) to complete 8 weeks of IMT. This project was registered as a clinical trial (NCT05196529) with clinicaltrials.gov. After completion of IMT, all groups experienced improvements in inspiratory muscle pressure (p&lt;0.001), 6-minute walk distance (p=0.002), resting heart rate (p=0.037), heart rate variability (p&lt;0.05), and symptoms related to sleep (p=0.009). In the ME/CFS group only, after completion of IMT, there were additional improvements with regard to vascular function (p=0.001), secretomotor function (p=0.023), the total weighted score (p=0.005) of the COMPASS 31 autonomic questionnaire, and symptoms related to pain (p=0.016). We found that after 8 weeks of IMT, people with PASC and/or ME/CFS could see some overall improvements in their autonomic function and symptomology.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104360"},"PeriodicalIF":1.9,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142392855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The activity of suprahyoid muscles during sevoflurane-induced gasping in mice","authors":"Saki Taiji,&nbsp;Takashi Nishino,&nbsp;Hisayo Jin,&nbsp;Mayumi Hashida,&nbsp;Shiroh Isono","doi":"10.1016/j.resp.2024.104355","DOIUrl":"10.1016/j.resp.2024.104355","url":null,"abstract":"<div><div>Sevoflurane-induced gasping in mice involves an enormous increase in inspiratory effort, mandibular movement, and a marked decrease in respiratory frequency (fR). We examined differences in breathing patterns and electromyogram activity (EMG_SH) of the suprahyoid muscles (SHMs) during eupnea under 3.2 % (1 MAC: minimum alveolar concentration) sevoflurane inhalation and sevoflurane-induced gasping under 6.5 % (2 MAC) sevoflurane inhalation in eight spontaneously breathing, tracheally intubated, adult mice. We found that the phasic EMG_SH is obtained only during inspiration in eupnea and gasping and that integrated EMG_SH increases more, as a percent of baseline (% baseline) than tidal volume (V_T) during gasping (median [interquartile range]; integrated EMG_SH: 720 [425–1965] vs. V_T: 300 [238–373], P &lt; 0.05). We also found that the onset of EMG_SH precedes the start of airflow while maintaining a bell-shaped EMG_SH contour, which characterizes the EMG of upper airway dilator (UAD) muscles during eupnea and gasping. Vigorous respiratory-related mandibular movements were never observed during eupnea but were observed in seven of 8 mice during sevoflurane-induced gasping. Our observations indicate that SHMs act as a preferentially activating UAD muscle, contributing to the development of mandibular respiratory movements.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104355"},"PeriodicalIF":1.9,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breathing pattern alteration from weanling to old age in male Sprague-Dawley rats","authors":"Mehdi Eslami-Behroozi,&nbsp;Payam Shahsavar,&nbsp;Reyhaneh Vali,&nbsp;Mohammad Reza Raoufy","doi":"10.1016/j.resp.2024.104357","DOIUrl":"10.1016/j.resp.2024.104357","url":null,"abstract":"<div><div>Respiratory patterns were investigated in male Sprague-Dawley rats throughout their lifespan, from weanling (1 month) to old age (24 months), under natural conditions. Both inter-breath interval (IBI) and respiratory volume (RV) were examined. Sample entropy suggested increasing irregularity in IBI but decreasing irregularity in RV until 12 months. According to detrended fluctuation analysis, alpha exponent of the IBI showed a bimodal pattern around the value 0.7. From 1–15 months, the alpha exponent for RV generally decreased to the value 0.5, but it increased again as the animals neared the end of their lifespan. Cross-sample entropy revealed increasing synchronization between IBI and RV until 12 months, then plateauing. Many measures demonstrated a transition around 12 months, potentially reflecting maturation of respiratory control mechanisms. The findings characterize complex dynamics of respiratory patterns across the rat lifespan, providing a normative foundation to identify deviations indicative of dysfunction or disease.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104357"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142372715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Safety and effectiveness of acute intermittent hypoxia during a single treatment at different hypoxic severities","authors":"Cory M. Smith,&nbsp;Owen F. Salmon","doi":"10.1016/j.resp.2024.104358","DOIUrl":"10.1016/j.resp.2024.104358","url":null,"abstract":"<div><h3>Purpose</h3><div>Examine the cardiovascular, muscular function, cognitive, and neural plastic responses to determine the safety and effectiveness of acute Intermittent hypoxia (AIH) at a low, high, and control fractional inspired oxygen (FiO₂) dosage</div></div><div><h3>Methods</h3><div>Thirteen human participants performed 30-min of AIH in 60-s intervals at FiO2’s of 0.21 (AIH₂₁), 0.15 (AIH₁₅), and 0.09 (AIH₉). Heart rate variability (root mean squared of successive differences; RMSSD), heart rate, oxygen saturation (SpO2), blood pressure, muscular strength, neuromuscular activation, cerebral hemodynamic responses, cognition, symptomology, and brain-derived neurotrophic factor (BDNF) responses were measured before (Pre-AIH), after (post-AIH), and at 20-min of recovery (Recovery-AIH)</div></div><div><h3>Results</h3><div>There were no differences between AIH protocols for heart rate, RMSSD, blood pressure, or SpO2. Muscular strength improved Post-AIH for AIH₁₅ (10 %) and AIH₉ (14 %) and remained elevated (6 %) at Recovery-AIH. Neuromuscular activation increased Pre-AIH to Post-AIH for AIH15 (10 %) and AIH₉ (11 %). Cerebral hemodynamic responses were not impacted between conditions. Both AIH₁₅ and AIH9 increased BDNF Post-AIH (62 %) and Recovery-AIH (63 %)</div></div><div><h3>Conclusion</h3><div>Acute intermittent hypoxia is generally safe and effective at producing neural plastic responses, but further examination of co-occurring cardiovascular diseases is needed. This study provides safety focused findings which will widen the adoption and refinement of AIH protocols</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104358"},"PeriodicalIF":1.9,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ratings of perceived effort during expiratory pressure tasks in healthy adults","authors":"Avery E. Dakin ,&nbsp;Michelle S. Troche","doi":"10.1016/j.resp.2024.104356","DOIUrl":"10.1016/j.resp.2024.104356","url":null,"abstract":"<div><h3>Purpose</h3><div>Expiratory muscle strength training (EMST) is a resistance exercise used to improve maximal expiratory pressure and airway protective functions (cough and swallow) in clinical populations. Although ratings of perceived exertion/effort (RPE) are commonly used in exercise prescription and monitoring, they have been underutilized in EMST and require investigation. Our study aims were to: (1) examine how healthy adults rate their effort using the EMST-150 device and MicroRPM respiratory manometer; (2) assess variability in RPE; and (3) compare RPE and relative expiratory pressures obtained from the two devices.</div></div><div><h3>Method</h3><div>Healthy adults completed thirty randomized expiratory maneuvers into a respiratory manometer and an EMST-150 device. RPE was measured using the Borg Category Ratio Scale. Linear mixed multilevel models were used for Aim 1 and 3, and coefficient of variation was used for Aim 2.</div></div><div><h3>Results</h3><div>Twenty healthy adults (Median age: 24.5 years) participated. Results demonstrated a strong positive relationship between resistive load and perceived effort when using both devices. Intra-individual variability in perceived effort decreased as resistive load increased. Participants produced an average of 18.2 % lower expiratory pressure when blowing into the manometer (relative to their maximum) than when blowing into the EMST device.</div></div><div><h3>Discussion</h3><div>Our results support the utilization of RPE in EMST research and clinical practice. The addition of RPE as a measure of intensity during respiratory exercise prescription may be used in future research to help refine EMST protocols and improve rehabilitation outcomes.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104356"},"PeriodicalIF":1.9,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Endomorphin-2 (Endo2) and substance P (SubP) co-application attenuates SubP-induced excitation and alters frequency plasticity in neonatal rat in vitro preparations","authors":"Stephen M. Johnson,&nbsp;Sarah M. Johnson,&nbsp;Jyoti J. Watters,&nbsp;Tracy L. Baker","doi":"10.1016/j.resp.2024.104351","DOIUrl":"10.1016/j.resp.2024.104351","url":null,"abstract":"<div><div>Substance P (SubP) and endomorphin-2 (Endo2) are co-localized presynaptically in vesicles of neurons adjacent to inspiratory rhythm-generating pre-Botzinger Complex (preBotC) neurons but the effects of co-released SubP and Endo2 on respiratory motor control are not known. To address this question, SubP alone or a combination of SubP and Endo2 (SubP/Endo2) were bath-applied in a sustained (15-min) or intermittent (5-min application, 5-min washout, x3) pattern at 10–100 nM to neonatal rat brainstem-spinal cord preparations. During neuropeptide application, SubP/Endo2 co-applications generally attenuated SubP-induced increases in burst frequency and decreases in burst amplitude. With respect to frequency plasticity (long-lasting increase in burst frequency 60 min post-neuropeptide application), SubP-induced frequency plasticity was increased with sustained SubP/Endo2 co-applications at 20 and 100 nM. Intermittent SubP/Endo2 co-applications tended to decrease the level of frequency plasticity induced by intermittent SubP alone applications. SubP/Endo2 co-applications revealed potentially new functions for neurokinin-1 (NK1R) and mu-opioid (MOR) receptors on respiratory rhythm-generating medullary neurons.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104351"},"PeriodicalIF":1.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142294047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The acute effect of respiratory muscle training on cortisol, testosterone, and testosterone-to-cortisol ratio in well-trained triathletes - exploratory study","authors":"Tomasz Kowalski ,&nbsp;Zbigniew Obmiński ,&nbsp;Wojciech Waleriańczyk ,&nbsp;Andrzej Klusiewicz","doi":"10.1016/j.resp.2024.104353","DOIUrl":"10.1016/j.resp.2024.104353","url":null,"abstract":"<div><div>The study investigated acute changes in cortisol (C) and testosterone (T) associated with a popular RMT method, voluntary isocapnic hyperpnoea (VIH), in well-trained triathletes. 19 athletes (7 females, 12 males) performed a VIH training session with pre- and post- serum C and T measurements. Repeated measures ANOVA was employed to analyze hormone changes during VIH, with additional time-sex interaction. Pearson correlation coefficient has been computed to identify the relationship between hormonal changes and age, anthropometric indices, respiratory muscle strength, and training experience. There was a statistically significant effect for C changes (F = 13.101, p = 0.002, η_p² = 0.421, ω² = 0.08). The C concentration was significantly lower after VIH (Mean Difference = −32.49 <em>± 39.13</em> nmol*L⁻¹). No significant effects for T, T/C ratio, and time-sex interactions were observed (p &gt; 0.05). Amongst many, significant correlations between the percentage of body fat and changes in C (r=-0.464, p=0.045), body mass and changes in T (r=0.516, p=0.024), height and changes in T (r=0.509, p=0.026) were found. VIH significantly lowered C concentration. No significant effects for T, T/C ratio, and no between-sex differences were observed. Noteworthy individual variability was observed in all the monitored indices. Significant correlations were found between acute hormone changes associated with VIH and selected anthropometric indices. The study provides initial insight into VIH’s role in athletes’ hormonal balance to possibly guide exercise prescription, autoregulation, arousal state management, and recovery practices in athletes.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":"331 ","pages":"Article 104353"},"PeriodicalIF":1.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1569904824001460/pdfft?md5=95f9e5352d854d42eb2f88ba588c5cf9&pid=1-s2.0-S1569904824001460-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142294049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}