Physiological Reports最新文献

This study aimed to investigate the impact of swim training intensity and duration on cardiac structure and function in mildly hypertensive women. Sixty-two mildly hypertensive women were randomized to 15 weeks of either (1) high-intensity swimming (HIS, n = 21), (2) moderate-intensity swimming (MOD, n = 21) or (3) control (CON, n = 20). Training sessions occurred three times per week. Cardiac measurements were conducted using echocardiography pre- and post-intervention. Both the HIS and MOD groups demonstrated significant within-group increases in left ventricular mass: 7.3% [1.2; 13.2] (p = 0.02) for HIS and 6.2% [0.5; 11.8] (p = 0.03) for MOD. The MOD group also demonstrated a significant increase in left ventricular internal dimension at end-diastole by 2.4% [0.2; 4.6] (p = 0.03). Post-hoc analysis of diastolic function markers revealed reduced mitral valve A velocity in both HIS (-14% [-25; -3], p = 0.02) and MOD (-13% [-23; -3], p = 0.01), leading to increased mitral valve E/A ratios of 27% [10; 47] (p = 0.003) and 22% [5; 40] (p = 0.01), respectively. Additionally, only MOD demonstrated increased left atrial diameter of 4.9% [0.7; 9.1] (p =0.02). A significant time×group effect (p = 0.02) existed for global longitudinal strain, which increased by 1.6% [0.2; 3.0] (p = 0.03) in MOD only. In conclusion, swim training for 15 weeks increased left ventricular mass and improved markers of diastolic function in mildly hypertensive women. These independent of exercise intensity and duration in mildly hypertensive women.

The immune response to acute hypoxemia may play a critical role in high-altitude acclimatization and adaptation. However, if not properly controlled, hypoxemia-induced inflammation may exacerbate high-altitude pathologies, such as acute mountain sickness (AMS), or other hypoxia-related clinical conditions. Several studies report changes in immune cell subsets at high altitude. However, the mechanisms underlying these changes, and if these alterations are beneficial or maladaptive, remains unknown. To address this, we performed multiparameter flow cytometry on peripheral blood mononuclear cells (PBMCs) collected throughout 3 days of high-altitude acclimatization in healthy sea-level residents (n = 20). Additionally, we conducted in vitro stimulation assays to test if high-altitude hypoxia exposure influences responses of immune cells to subsequent inflammatory stimuli. We found several immune populations were altered at high altitude, including monocytes, T cells, and B cells. Some changes in immune cell populations are potentially correlated with AMS incidence and severity. In vitro high-altitude PBMC cultures stimulated with lipopolysaccharide (LPS) showed no changes in pro-inflammatory cytokine production after 1 day at high-altitude. However, by day three pro-inflammatory cytokine production in response to LPS decreased significantly. These results indicate that high-altitude exposure may initiate an inflammatory response that encompasses innate immune sensitization, with adaptive immune suppression following acclimatization.

The waveform of ventricular action potential (AP) is a key determinant of the cardiac cycle, a marker of beating pathophysiology, and a target for anti-arrhythmic drug design. The information contained in the waveform, though, is limited to the actual dynamics of the AP under consideration. By measuring quasi-instantaneous current-voltage relationships during repolarization, I propose a three-dimensional representation of the ventricular AP which includes potential dynamic responses that the beat can show when electrically perturbed. This representation is described in the case of a numerically reconstructed ventricular AP, but it can be, at least partially, derived in real cardiomyocytes. Simulation allows to disclose the potentialities and the limitations of the approach, that can be extended to any non-cardiac AP. By reporting, at any AP time, the ion current available within the physiological membrane potential range at that time, the representation makes all together available: (1) refractory period, (2) thresholds for eliciting full or calcium-driven APs, (3) threshold for all-or-none repolarization, (4) membrane resistance during repolarization, (5) the safety of membrane repolarization. It provides further evidence of a negative membrane resistance during the late phase of ventricular AP and a quantitative estimate of repolarization reserve (RR), key determinants of repolarization dynamics.

Obesity paradox refers to the clinical observation that when acute cardiovascular decompensation occurs, patients with obesity may have a survival benefit. This apparently runs counter to the epidemiology of obesity, which may increase the risk for non-communicable diseases (NCDs). The scientific community is split on obesity paradox, with some supporting it, while others call it BMI paradox. This review: (a) defines the obesity paradox, and its proposed role in overall mortality in NCDs; (b) delineates evidence for and against obesity paradox; (c) presents the importance of using different indices of body mass to assess the risk in NCDs; (d) examines the role of metabolically healthy obesity in obesity paradox, and emerging importance of cardio-respiratory fitness (CRF) as an independent predictor of CVD risk and all-cause mortality in patients with/without obesity. Evidence suggests that the development of obesity and insulin resistance are influenced by genetic (or ethnic) make up and dietary habits (culture) of the individuals. Hence, this review presents lean diabetes, which has higher total CVD and non-CVD mortality as compared to diabetics with obesity and the possibility of maternal factors programming cardiometabolic risk during fetal development, which may lead to a paradigm shift in our understanding of obesity.

The kidneys are essential for glucose homeostasis, as they perform gluconeogenesis, utilize glucose, and reabsorb glucose. Reabsorption is performed by SGLT2, which is responsible for about 90%. However, little is known about how renal glucose handling is altered in patients with chronic kidney disease (CKD). SGLT2 inhibitors have demonstrated efficacy in suppressing CKD progression in clinical trials, but their mechanisms are not fully understood. Therefore, this study aimed to evaluate how each uninephrectomy (UNx) and SGLT2 inhibitor affects blood glucose concentrations and SGLTs dynamics in rats with type 2 diabetes mellitus. Male rats were divided into four treatment groups: sham + placebo, sham + dapagliflozin, UNx + placebo, and UNx + dapagliflozin. There were few group differences in food intake or body weight, but blood glucose concentrations continued to rise in the sham + placebo, whereas this rise was delayed for several weeks in the UNx + placebo, and largely suppressed by dapagliflozin. SGLT2 mRNA expression was significantly lower in the UNx group, but SGLT1 mRNA expression did not significantly differ. Dapagliflozin did not alter SGLT1 or SGLT2 mRNA expression. In animal models of diabetes, renal glucose reabsorption appears likely to be a major contributor to the development of hyperglycemia.

Spinal pain (SP) remains the leading cause of disability worldwide. The present study aimed to establish a current prevalence of SP and associated determinants in Wales by retrospectively analyzing data from the National Survey for Wales Dataset (NSWD). The NSWD is a large-scale cross-sectional, representative sample of adults across Wales, UK. A univariable and multivariable regression analysis was carried out on self-reported answers to health and well-being questions contained within the NSWD (2016-2020) to determine the strength of association of various determinants and comorbidities related to spinal pain. A total population of 38,954 of adults were included in the analysis. The study population included interview responses of 21,735 females and 17,219 males. The prevalence of SP in Wales was 4.95% (95% CI: 4.74%-5.15%) with a total of 847 males (4.92%, CI: 4.60%-5.24%) and 1082 females (4.98%, CI: 4.69%-5.27%) reporting spinal pain. The age group with the highest prevalence of SP was in the 70+ years age group for both males (5.44%, CI: 4.82%-6.07%) and females (5.95%, CI: 5.37%-6.54%). The strength of association between age and SP reaches its peak at 50-59 years with an adjusted Odds Ratio (aOR) of 3.74 (p = <0.001), that decreases slightly at 60-69 years and 70+ years. For various comorbidities included in the NSWD, significant associations with SP were confirmed for: mental illness (aOR = 1.42, p = <0.001), migraine (aOR = 2.73, p = <0.001), nervous system issues (aOR = 1.61, p = <0.001), arthritis (aOR = 1.30, p = <0.001) and issues with bones/joints/muscles (aOR = 1.93, p = <0.001). For lifestyle factors, associations were confirmed for current smokers (aOR = 1.41, p = <0.001) and ex-smokers (aOR = 1.23, p = 0.003). This study demonstrates a low prevalence of SP in Wales when compared to global estimates and strong associations to a variety of determinants. This still represents a significant societal burden and these findings may help inform public health initiatives to encourage prevention and evidence-based interventional strategies and ultimately, improve the quality of life for those suffering with SP in Wales.

Logo for Physiological Reports' 10th anniversary year.

High caliber master athletes provide a valuable model for studying inherent physiological aging and performance capacity, without the confounding factor of physical inactivity. Despite the remarkable achievements of female master athletes, their participation rates remain significantly lower than those of their male counterparts, particularly at more advanced ages. This review examines the biological sex gap in sports participation among master athletes and the subsequent disparity in empirical research, thereafter exploring possible contributing factors. It highlights the importance of studying female master athletes to better understand the aging process and offers recommendations to address current evidence gaps. The need for more comprehensive mechanistic data on highly trained older women, novel cataloguing and analysis of real-world datasets, case studies/series, and longitudinal research are also emphasized. Although analyzing the records of female master athletes as a surrogate to determine age-related physiological and performance changes is a common approach, the process may be hindered by the considerably lower participation rates of women. Therefore, an important step toward bridging these gaps is the longitudinal, integrative study of female athletes engaged in lifelong exercise. Such analyses would improve our understanding of senescence in women and may inform interventions targeting the promotion of physical function in older adults.

Recent discoveries have identified intrapulmonary bronchopulmonary anastomoses (IBAs) as a relatively common phenomenon forming intrapulmonary right-to-left shunts. This study hypothesizes that IBAs play a significant role in the pathophysiology of heart failure. We aim to investigate the impact of these intrapulmonary right-to-left shunts on pulmonary arterial and venous pressures in heart failure patients, utilizing mixed venous oxygen saturation (SvO₂) as a key measurement. This study included 237 patients with heart failure who underwent cardiac catheterization. The relationships between SvO₂ and pulmonary artery systolic pressure (sPAP), pulmonary artery wedge pressure (PAWP), and left ventricular end-diastolic pressure (LVEDP) were examined using various statistical methods (single regression analysis, partial correlation analysis, structural equation modeling, and Bayesian estimation). All statistical methods that we performed showed that SvO₂ was significantly and negatively correlated with both sPAP and PAWP (p < 0.01, respectively). However, SvO₂ did not significantly correlate with LVEDP. These results suggest that a decrease in SvO₂ leads to an increase in PAWP and sPAP, while LVEDP is only passively influenced by PAWP. This phenomenon likely reflects the impact of an intrapulmonary right-to-left shunt caused by IBAs. The decrease in SvO₂ causes an increase in sPAP and may also cause an increase in PAWP via IBAs.

Sport-related concussion (SRC) is associated with cardiovascular autonomic nervous system (ANS) dysfunction. This study examines resting cardiovascular ANS activity in adolescents with SRC compared to controls early post-injury and after clinical recovery, analyzing its correlation with symptom severity and recovery outcomes. Cardiovascular ANS function was evaluated using heart rate variability (HRV), systolic blood pressure variability (SBPV) and baroreflex sensitivity (BRS). Symptoms were assessed via the Post-Concussion Symptom Scale, and recovery outcomes were categorized by recovery duration. Following acute SRC, no significant differences in HRV, SBPV or BRS were found between SRC and control groups, nor between those with delayed or normal recovery. Post-recovery, SRC participants had higher low frequency (LF) SBPV than controls and their initial assessment. When concussed participants were symptomatic, LF SBPV correlated directly with overall, cognitive, and fatigue symptom severity, while high frequency (HF) HRV inversely correlated with affective symptoms (Spearman's rho: 0.4-0.6). Resting cardiovascular ANS function remains unchanged in adolescent athletes acutely after SRC, suggesting it has limited diagnostic and prognostic potential. Although some correlations between individual symptom domains and ANS activity were observed, they were not significantly different from asymptomatic controls, limiting the ability to interpret these findings.