Journal of applied physiology最新文献

{"title":"Breakfast skipping suppresses vascular endothelial function of the brachial artery after lunch.","authors":"Hideaki Kashima, Natsuki Seo, Masako Yamaoka Endo, Masako Kanda, Kohei Miura, Naomi Kashima, Akira Miura, Yoshiyuki Fukuba","doi":"10.1152/japplphysiol.00681.2023","DOIUrl":"https://doi.org/10.1152/japplphysiol.00681.2023","url":null,"abstract":"<p><p>Breakfast skipping has been suggested to be associated with cardiovascular diseases. However, whether breakfast skipping affects vascular endothelial function (VEF), a marker of cardiovascular diseases, remains unclear. This study aimed to investigate the impact of breakfast consumption (Eating trial) and skipping (Skipping trial) on brachial artery (BA) VEF in healthy breakfast eaters. A total of nine healthy individuals (four females and five males) either had breakfast between 8:30 and 9:00 or skipped it and had lunch between 12:00 and 12:30, followed by a 3-h rest period until 15:30. For BA VEF evaluation, flow-mediated dilation (FMD) was measured using ultrasound before and after breakfast and lunch. FMD was calculated as the percentage change in BA diameter normalized to the shear rate area under the curve (FMD/SR_AUC). Blood glucose, plasma insulin, and plasma free fatty acid levels in capillaries were measured before and after breakfast and lunch. At 15:30, the Eating trial, but not the Skipping trial, significantly increased FMD/SR_AUC from baseline (<i>p</i> = 0.006). The Skipping trial showed significantly lower changes in FMD/SR_AUC from 8:30 than the Eating trial at 15:30 (<i>p</i> < 0.001). We found a significant inverse correlation between changes in FMD/SR_AUC between 8:30 and 15:30 and peak glucose levels after lunch (r = -0.882, <i>p</i> < 0.001) and with an incremental area under the curve for glucose between 8:30 and 15:30 (r = -0.668, <i>p</i> < 0.001). These results suggest that a single bout of breakfast skipping can suppress BA VEF in the afternoon due to postlunch hyperglycemia.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142287938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increased luminal area of large conducting airways in patients with COVID-19 and post-acute sequelae of COVID-19: A retrospective case-control study.","authors":"Solomiia Zaremba, Alex J Miller, Erik A Ovrom, Jonathon W Senefeld, Chad C Wiggins, Paolo B Dominelli, Ravindra Ganesh, Ryan T Hurt, Brian J Bartholmai, Brian T Welch, Juan G Ripoll, Michael J Joyner, Andrew H Ramsook","doi":"10.1152/japplphysiol.00573.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00573.2024","url":null,"abstract":"<p><p>Coronavirus disease 2019 (COVID-19) is associated with enlarged luminal areas of large conducting airways. In 10-30% of patients with acute COVID-19 infection, symptoms persist for more than 4 weeks (referred to as post-acute sequelae of COVID 19, or PASC), and it is unknown if airway changes are associated with this persistence. Thus, we aim to investigate if luminal area of large conducting airways is different between PASC and COVID-19 patients, and healthy controls. In this retrospective case-control study 75 patients with PASC (48 females) were age-, height-, and sex-matched to 75 individuals with COVID-19 and 75 healthy controls. Using three-dimensional digital reconstruction from computed tomography imaging, we measured luminal areas of seven conducting airways, including trachea, right and left main bronchi, bronchus intermediate, right and left upper lobe, and left lower lobe bronchi. Kruskal-Wallis H test was used to compare measurements between the three groups, as appropriate. Airway luminal areas between COVID-19 and PASC groups were not different (<i>p</i>>0.66). There were no group differences in airway luminal area (PASC vs. control) for trachea and right main bronchus. However, in the remaining five airways, airway luminal areas were 12% to 39% larger among PASC patients compared to controls (all, <i>p</i><0.05). Patients diagnosed with COVID-19 and PASC have greater airway luminal area in most large conducting airways compared to healthy controls. No differences in luminal area between patients with COVID-19 and PASC suggest persistence of changes or insufficient time for reversal of changes.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142287939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal changes in the mouse gut bacteriota influenced by host sex, diet, and exercise.","authors":"Robert A Dowden, Lee J Kerkhof, Paul J Wisniewski, Max M Häggblom, Sara C Campbell","doi":"10.1152/japplphysiol.00487.2023","DOIUrl":"https://doi.org/10.1152/japplphysiol.00487.2023","url":null,"abstract":"<p><p>The gut microbiota plays an important role in host physiology. However, the effects of host sex, lifestyle, and temporal influences on the bacterial community within the gut remain ill-defined. To address this gap, we evaluated 56 male and female mice over a 10-week study to assess the effects of sex, diet, and exercise on gut community dynamics. Mice were randomly assigned to high-fat or control diet feeding and had free access to running wheels or remained sedentary throughout the study period. The fecal bacterial community was characterized by rRNA operon amplicon profiling via nanopore sequencing. Differential abundance testing indicated that ~200 bacterial taxa were significantly influenced by sex, diet, or exercise (4.2% of total community), which also changed over time (82 taxa, 1.7% of total community). Phylogenetic analysis of taxa closely related to <i>Dysosmobacter welbionis</i> and several members of the family <i>Muribaculaceae</i> were examined more closely and demonstrated distinct species/strain-level sub-clustering by host sex, diet, and exercise. Collectively, this data suggests that sex and lifestyle can alter the gut bacteriota at the species/strain-level which may play a role in host health. These results also highlight the need for improved characterization methods to survey microbial communities at finer taxonomic resolution.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142287959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute normobaric hypoxia causes a rightward shift in the torque-frequency relationship, but has no effect on post-activation potentiation.","authors":"Christina D Bruce, Mathew I B Debenham, Brian H Dalton, Chris J McNeil","doi":"10.1152/japplphysiol.00378.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00378.2024","url":null,"abstract":"<p><p>Low fractions of inspired oxygen (FI_O2; i.e., hypoxia) affect aspects of skeletal muscle contractility in humans, but it remains unclear if post-activation potentiation (PAP) and the torque-frequency (T-F) relationship are altered. We investigated the effects of two (H2) and four hours (H4) of normobaric hypoxia (FI_O2=0.11±0.47) on the magnitude of PAP of the knee extensors (KE) and the T-F relationship of the dorsiflexors (DF) in 13 and 12 healthy participants, respectively. To assess PAP, a resting twitch was evoked via femoral nerve stimulation before, and 2-300 s following a 10-s maximal voluntary contraction (MVC). A T-F relationship was obtained by stimulating the common fibular nerve with a single pulse and 1-s trains between 5-100 Hz. During hypoxia, peripheral oxygen saturation decreased by ~18% from 98.0±0.8% at baseline (P<0.001). MVC force and voluntary activation (VA) of the KE were lower than baseline throughout hypoxia (e.g., ~8 and ~5%, respectively at H2; P≤0.027); however, the magnitude of PAP was not altered by hypoxia (P≥0.711). Surprisingly, PAP did increase with time across the control day (P≤0.012). MVC torque and VA of the DF were unaffected by hypoxia (P≥0.127), but the estimated frequency required to evoke 50 % of 100-Hz torque increased by ~1.2 Hz at H2 (P≤0.021). These results imply that two hours of normobaric hypoxia were sufficient to: i) impair neural drive to the KE but not the mechanism(s) responsible for PAP, and ii) lead to a rightward shift of the T-F relationship for the DF.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142287937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex Differences in Biomarkers of End-Organ Damage following Exertional Heat Stroke in Humans.","authors":"Kari C Goodwin, Gabrielle E W Giersch, Timothy A Murray, David W DeGroot, Nisha Charkoudian","doi":"10.1152/japplphysiol.00463.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00463.2024","url":null,"abstract":"<p><p>Women are participating in military and athletic activities in the heat in increasing numbers, but potential sex differences in sequelae from exertional heat illness remain poorly understood. We tested the hypothesis that women suffering from exertional heat stroke (EHS) would have similar severity of organ damage biomarkers compared to men, as measured in a hospital setting. We studied women and men presenting with EHS to the emergency department at Fort Moore, GA. We measured creatinine (CR), creatine kinase (CK), alanine-transaminase (ALT), aspartate aminotransferase (AST), and estimated glomerular filtration rate (eGFR). Core temperature was also assessed by medical personnel. Biomarker data were obtained for 62 EHS cases (11 women). Men were significantly taller, and heavier, had larger BMI and body surface area (p<0.05 for all). Highest recorded body core temperature was not different between groups (women: 41.11°C (40.06,41.67); men: 41.11°C (40.28,41.72), p=0.57). Women had significantly lower peak CR (women: 1.39 (1.2,1.48) mgꞏdL^-1; men: 1.75 (1.53,2.16) mgꞏdL^-1, p<0.01) and peak CK (women: 584 (268,2412) UꞏL^-1; men: 2183 (724,5856) U•L^-1, p=0.02). Peak ALT and AST were not different between groups; during recovery time points, ALT and AST were either similar or lower in women. Women spent approximately half as much time in the hospital following admittance compared to men. Our findings suggest that women may be less susceptible to organ injury resulting from EHS. Further research is necessary to understand the pathophysiology underlying these differences and how biomarkers of end-organ damage severity can differ between women and men following EHS.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142287957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Induced Blood Flow Oscillations at 0.1 Hz Protects Oxygenation of Severely Ischemic Tissue in Humans.","authors":"K Austin Davis, Nasrul A Bhuiyan, Benjamin J McIntyre, Viet Q Dinh, Caroline A Rickards","doi":"10.1152/japplphysiol.00438.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00438.2024","url":null,"abstract":"<p><p>Generating 10-second (~0.1 Hz) fluctuations or \"oscillations\" in arterial pressure and blood flow blunts reductions in cerebral tissue oxygenation in response to 15-20% reductions in cerebral blood flow. To examine the effect of 0.1 Hz hemodynamic oscillations on tissue oxygenation during severe ischemia, we developed a partial limb ischemia protocol targeting a 70-80% reduction in blood flow. We hypothesized that 0.1 Hz hemodynamic oscillations would attenuate reductions in tissue oxygenation during severe ischemia. 13 healthy humans (6M, 7F; 27.3±4.2 y) completed two experimental protocols separated by ≥48 h. In both conditions, an upper arm cuff was used to decrease brachial artery (BA) blood velocity by ~70-80% from baseline. In the oscillation condition (0.1 Hz), 0.1 Hz hemodynamic oscillations were induced by intermittently inflating and deflating bilateral thigh cuffs every 5-s during forearm ischemia. In the control condition (0 Hz), the thigh cuffs were inactive. BA blood flow, forearm tissue oxygenation (SmO2), and arterial pressure were measured continuously. The initial reduction in BA blood velocity was tightly matched between protocols (0 Hz: -76.9±7.9% vs. 0.1 Hz: -75.5±7.4%, p=0.49). While 0.1 Hz oscillations during forearm ischemia had no effect on the reduction in BA velocity (0 Hz: -73.0 ± 9.9% vs. 0.1 Hz: -73.3 ± 8.2%, p=0.91), the reduction in SmO2 was attenuated (0 Hz: -35.7±8.6% vs. 0.1 Hz: -27.2±8.9%; p=0.01). These data provide further evidence for the use of 0.1 Hz hemodynamic oscillations as a potential therapeutic intervention for conditions associated with severe tissue ischemia (e.g., hemorrhage and stroke).</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142287940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Cardiovascular Responses to the 100-Mile Western States Endurance Run.","authors":"Matthew C Babcock, Omar B El-Kurd, James R Bagley, Braxton A Linder, Nina L Stute, Soolim Jeong, Joseph D Vondrasek, Joseph C Watso, Austin T Robinson, Gregory J Grosicki","doi":"10.1152/japplphysiol.00412.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00412.2024","url":null,"abstract":"<p><p>Ultramarathon participation is growing in popularity and exposes runners to unique stressors including extreme temperatures, high altitude, and exceedingly long exercise duration. However, the acute effects of ultramarathon participation on the cardiovascular system are not well understood.</p><p><strong>Purpose: </strong>To determine the acute effects of trail ultramarathon participation on central artery stiffness and hemodynamics.</p><p><strong>Methods: </strong>Forty-one participants (9F, 32M) participating in the 2023 Western States Endurance Run underwent measures of carotid-femoral pulse wave velocity (cf-PWV) and pulse wave analysis pre- and <1h post-race. Subendocardial viability ratio (SEVR) was calculated from central blood pressure (BP) waveforms. Serum was analyzed for creatine kinase (CK) activity as a measure of muscle damage. Normally distributed data are presented as mean±SD and non-normally distributed data are presented as median (interquartile range).</p><p><strong>Results: </strong>Runners were middle-aged and generally lean (age=44±9 y, BMI=22.7±1.8 kg●m^-2). There was no difference in cf-PWV from pre- to post-race (pre=6.4±1.0, post=6.2±0.85 m/s, p=0.104), a finding that persisted after adjusting for mean arterial pressure (p=0.563). Systolic and diastolic BP were lower post-race (pre=129/77±9/7, post=122/74±10/8 mmHg, ps<0.001). Augmentation index (AIx; pre=17.3±12.2, post=6.0±13.7%, p<0.001), AIx normalized to a heart rate of 75bpm (p=0.043), reflection magnitude (pre=55.5(49.0-60.8), post=45.5(41.8-48.8) %, p<0.001), and SEVR (pre=173.0(158.0-190.0), post=127.5(116.5-145.8) %, p<0.001) were reduced post-race. CK increased markedly from pre- to post-race (pre=111(85-162), post=11,973(5,049-17,954) U/L, p<0.001).</p><p><strong>Conclusions: </strong>Completing a 161-km trail ultramarathon does not affect central arterial stiffness and acutely reduces BP despite eliciting profound muscle damage. However, the reduced post-race SEVR suggests a short-term mismatch between myocardial work and coronary artery perfusion.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142287936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reply to Henry and Tsuda","authors":"Wayne Mitzner, Gerald C. Smaldone","doi":"10.1152/japplphysiol.00583.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00583.2024","url":null,"abstract":"Journal of Applied Physiology, Volume 137, Issue 3, Page 675-675, September 2024. <br/>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fresh look at the relationship between alveolar surface area and volume","authors":"Frank S. Henry, Akira Tsuda","doi":"10.1152/japplphysiol.00524.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00524.2024","url":null,"abstract":"Journal of Applied Physiology, Volume 137, Issue 3, Page 674-674, September 2024. <br/>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does wearing high heels really improve walking economy in flat shoes?","authors":"Alexander C. Berry, L. Bruce Gladden","doi":"10.1152/japplphysiol.00313.2024","DOIUrl":"https://doi.org/10.1152/japplphysiol.00313.2024","url":null,"abstract":"Journal of Applied Physiology, Volume 137, Issue 3, Page 689-689, September 2024. <br/>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}