Frontiers in Physiology最新文献

[This corrects the article DOI: 10.3389/fphys.2023.1164943.].

[This corrects the article DOI: 10.3389/fphys.2018.00051.].

[This corrects the article DOI: 10.3389/fphys.2025.1649593.].

Objectives: This meta-analysis assessed the impact of low-volume high-intensity interval training (LV-HIIT) on body composition and cardiovascular health in children and adolescents, while examining potential moderating factors.

Methods: A systematic search was conducted in PubMed, Web of Science, the Cochrane Library (CENTRAL), and CNKI from inception to April 2025. A three-level random-effects model was used to estimate the overall effects, and subgroup analyses supplemented with meta-regression were performed to explore potential moderators and sources of heterogeneity.

Results: A total of 23 studies (996 participants, including 246 females) were included, with 6 studies on normal-weight and 17 on overweight/obese individuals. Compared with controls, low-volume high-intensity interval training (LV-HIIT) significantly reduced BMI (g = -1.24), fat mass (g = -0.99), body fat (g = -0.89), waistline (g = -0.42), weight (g = -0.34), and SBP (g = -0.37), while improving VO₂max (g = 1.35). No significant differences were observed versus MICT. Subgroup and dose-response regressions suggested that weight status, age, intervention duration, training frequency, repetitions, and per-repetition time may alter the observed effects. Descriptive findings indicated comparable effects of LV-HIIT with small-sided games and sprint interval training but greater benefits over moderate-intensity interval training.

Conclusion: LV-HIIT can effectively and time-efficiently improve body composition and cardiovascular health in children and adolescents, with overall effects comparable to MICT. Exercise prescriptions should carefully consider weight status, age, and intervention characteristics; however, given the limited number of studies and potential bias, the conclusions should be interpreted with caution. Limited descriptive comparisons indicate that LV-HIIT produces effects similar to SSG and SIT, and may offer greater benefits than MIIT.

Systematic review registration: https://osf.io/exhjm/.

Objectives: Although dyspnea is the most common symptom of pleural effusion (PE), its physiological basis has not yet been fully elucidated. The aim of this work is to investigate the cause of dyspnea before therapeutic thoracentesis (TT) by analyzing the lack of dyspnea relief after TT.

Methods: We retrospectively analyzed data gathered during TT. Among others, our database includes measurements of instantaneous pleural pressure (Ppl) in the ipsilateral hemithorax and airflow in the mouth (during TT), as well as arterial gas tensions (AGT) and dyspnea characterized quantitatively via the Modified Borg Scale (before and after TT). As the Borg scale is a subjective measure, the change in dyspnea (dB) was used in reliable quantitative analyses. Differences in various parameters and their changes between patients who reported dyspnea relief and the other patients (the YES and NO groups, respectively) were studied. Additionally, correlations between dB and these parameters (and their changes) were studied.

Results: Only the amplitude of Ppl changes related to breathing after TT was significantly different (higher) in group NO than in group YES (p < 0.003; the large effect size). dB correlated with this amplitude and the volume of withdrawn fluid (r = -0.51 and 0.51, respectively), but it correlated with neither changes in AGT nor minute ventilation.

Conclusion: The results suggest that the key mechanism of dyspnea in patients with malignant PE is related to reduced total lung compliance due to collapse of a lung part, leading to an increase in the work of breathing required to maintain adequate minute ventilation.

Traditional management of acid-related diseases, including gastroesophageal reflux disease, Helicobacter pylori infection, and peptic ulcer disease, primarily relies on proton pump inhibitors, which have notable limitations in acid suppression efficacy that hinder optimal treatment outcomes. Potassium-competitive acid blockers offer a novel approach with improved pharmacokinetic and pharmacodynamic properties, enhancing acid suppression and clinical efficacy in acid-related disease management. This narrative review evaluates the role of potassium-competitive acid blockers in acid-related disease management, comparing the pharmacokinetic, pharmacodynamic, clinical efficacy, and safety profiles of currently available agents. A comprehensive literature search from January 2002 to June 2024 was conducted across multiple databases to gather data on the efficacy and safety of potassium-competitive acid blockers. Potassium-competitive acid blockers showed comparable or superior clinical efficacy and generally comparable safety in various clinical settings vs. comparator proton pump inhibitors, particularly in managing erosive esophagitis, H. pylori eradication, and peptic ulcer disease. Potassium-competitive acid blockers, of which vonoprazan is the most well studied, offer comparable or improved therapeutic outcomes over traditional proton pump inhibitors, making them a valid option for several acid-related disease indications.

Myocardial infarction (MI) often induces acute kidney injury (AKI) via systemic hypoperfusion and oxidative stress, yet the protective mechanisms of exercise remain unclear. This study investigated whether intermittent exercise alleviates MI-induced AKI through the insulin-like growth factor-1 (IGF-1)/PI3K/AKT signaling pathway. An AKI model was established in mice via coronary artery ligation, followed by moderate-intensity intermittent treadmill training for 4 weeks. Echocardiography, serum biochemical markers, renal histology, RT-qPCR, and Western blotting were used to assess cardiac and renal function, inflammatory cytokines, oxidative stress, apoptosis, and IGF-1/PI3K/AKT signaling. In vitro, H₂O₂-treated NRK renal cells were used to mimic oxidative damage. Recombinant human IGF-1 (rhIGF-1), AMPK agonist AICAR, IGF-1 receptor inhibitor NVP-AEW541, and PI3K inhibitor LY294002 were applied to explore the pathway's involvement in exercise-induced renoprotection. MI led to impaired cardiac function, renal structural injury, elevated BUN and MDA levels, increased expression of IL-6, TNF-α, Bax, and Cleaved Caspase-3, and decreased SOD activity. Intermittent exercise improved cardiac output, attenuated renal injury, enhanced antioxidant capacity, and upregulated IGF-1 expression and its downstream PI3K/AKT signaling. In vitro, rhIGF-1 and AICAR mimicked the protective effects of exercise, while IGF-1R or PI3K inhibitors partially abolished these effects. These findings suggest that intermittent exercise ameliorates MI-induced AKI by activating the IGF-1/PI3K/AKT pathway, thereby exerting anti-inflammatory, antioxidant, and anti-apoptotic effects. This study highlights the role of exercise-induced IGF-1 in heart-kidney axis protection and provides a mechanistic basis for therapeutic interventions targeting MI-related renal complications.

Background: Chronic lower respiratory diseases (CLRDs) remain major causes of global mortality. Because conventional inflammatory markers have limited prognostic utility, we developed and validated the relative neutrophil-monocyte-lymphocyte-albumin ratio (NMLAR), defined as (Neutrophil% × Monocyte% × 100)/(Lymphocyte% × Albumin [g/dL]), as a novel biomarker to predict CLRD-specific mortality.

Methods: Immune infiltration of CLRDs was analyzed based on GEO datasets. We then analyzed 9,236 adults with CLRD from NHANES 1999-2014, excluding individuals with missing core variables. Machine learning algorithms (Boruta, SVM-RFE, XGBoost) were applied to identify key predictors. Cox proportional hazards models and restricted cubic spline (RCS) functions were used to evaluate the association between NMLAR and mortality outcomes, and stratified analyses were conducted across clinically relevant subgroups. Model performance was assessed by Harrell's C-index, calibration plots, and decision-curve analysis (DCA). Findings were externally validated in NHANES 2015-2018 (n = 2,107), the MIMIC-IV v3.1 ICU cohort (n = 2,120), and a real-world Zhejiang Provincial ICU cohort (n = 161).

Results: Immune profiling showed increased neutrophils/monocytes and reduced lymphocytes in CLRD and acute states. Higher baseline NMLAR was consistently associated with increased risks of both all-cause and CLRD-specific mortality and demonstrated superior predictive performance compared with conventional inflammatory markers. In NHANES, fully adjusted models indicated an approximately linear dose-response, with each 1-unit increment in NMLAR corresponding to a ∼7% higher risk of all-cause mortality and an ∼8% higher risk of CLRD-specific mortality. In the MIMIC cohort, NMLAR remained independently associated with 14-365-day mortality even after adjustment for critical care-specific covariates (SOFA score, CRRT, invasive mechanical ventilation, vasopressor use), with a threshold effect identified at 12.10. In the Zhejiang ICU cohort, NMLAR independently predicted 30-day mortality (HR per unit increase ≈1.09), with a threshold at 13.32. Notably, models derived from NHANES demonstrated moderate discriminatory ability, satisfactory calibration, and clinical net benefit when externally validated in both ICU cohorts, underscoring the robustness and generalizability of NMLAR as a prognostic biomarker across diverse clinical settings.

Conclusion: NMLAR is a simple, robust, and clinically applicable biomarker for mortality risk in CLRD, demonstrating consistent prognostic value across population-based, critical care, and real-world cohorts.

Background: Cross-frequency coupling (CFC), particularly phase-amplitude coupling (PAC), reflects hierarchical interactions between neural oscillations and plays a critical role in sensorimotor integration. However, its functional relevance during balance control under sensory perturbations remains insufficiently understood.

Objective: This study aimed to investigate PAC characteristics during postural control tasks of varying difficulty in elite freestyle aerial skiers versus non-athlete controls.

Methods: EEG signals and center of pressure (COP) data were recorded from participants performing six standing balance tasks on stable and unstable surfaces. Postural control was assessed using center of pressure data, which represent the point location of the body's vertical ground reaction force vector and are commonly used to quantify sway and balance performance during stance. Mean Vector Length Modulation Index (MVLmi) and PAC analyses were applied to assess oscillatory interactions.

Results: Surface instability significantly modulated PAC strength across frequency bands (P < 0.05). Athletes exhibited task-specific enhancements in alpha-gamma and delta-gamma coupling during single-leg and double-leg stance. These coupling patterns were more spatially localized and showed trends consistent with superior postural control. In contrast, non-athletes showed widespread PAC increases under perturbation, but with less effective balance performance. Hemispheric asymmetries were observed during single-leg stance: athletes demonstrated contralateral dominance during right-leg tasks and ipsilateral coupling shifts during unstable left-leg stance, indicating dynamic lateralized control shaped by training. Across conditions, athletes showed higher PAC strength and lower sample entropy, reflecting more efficient and adaptable cortical strategies for postural regulation.

Conclusion: PAC strength is closely linked to postural performance and varies with task complexity and surface condition. These findings highlight the role of training-induced neuroplasticity in modulating cortical dynamics for balance control, offering new insights for targeted neuromodulatory interventions and neurofeedback-based training strategies.

Background: Post-COVID-19 syndrome (PCS) describes a constellation of persistent or new symptoms lasting beyond the acute phase of SARS-CoV-2 infection. Emerging evidence suggests that exercise is a cost-effective and accessible intervention that may enhance pulmonary function, improve cardiopulmonary circulation, regulate emotional status, and alleviate symptoms of PCS. However, robust evidence supporting the efficacy of exercise therapy in PCS remains limited. This systematic review and meta-analysis aimed to elucidate the therapeutic potential of exercise therapy in PCS.

Method: A search of the PubMed, Embase, Web of Science, and Ovid databases up to March 25, 2025 yielded 33 randomized controlled trials (with 2,895 participants) for meta-analysis.

Result: The results showed that exercise therapy significantly improved the multi-dimensional outcomes of patients with PCS. Bayesian network meta-analysis indicated that the combination of aerobic exercise and respiratory muscle training had the best effect on lung function. Multimodal exercise significantly improved the results of the six-minute walk test, the dyspnea score, and peak oxygen uptake. Mental Health and Mental Component Summary scores improved significantly in the group that received exercise therapy (P<0.01).

Conclusion: The results of this meta-analysis confirm that exercise can significantly improve quality of life and the emotional state of patients with PCS. They also provide evidence for a treatment strategy in patients with post-COVID-19 sequelae.

Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier CRD420251034187.