-
Cardiology 2023Space travel imposes significant gravitational and radiation stress on both cellular and systemic physiology, resulting in myriad cardiovascular changes that have not...
INTRODUCTION
Space travel imposes significant gravitational and radiation stress on both cellular and systemic physiology, resulting in myriad cardiovascular changes that have not been fully characterized.
METHODS
We conducted a systematic review of the cellular and clinical adaptations of the cardiovascular system after exposure to real or simulated space travel in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed and Cochrane databases were searched in June 2021 for all peer-reviewed articles published since 1950 related to the following search terms entered in separate pairs: "cardiology and space" and "cardiology and astronaut." Only cellular and clinical studies in English concerning the investigation of cardiology and space were included.
RESULTS
Eighteen studies were identified, comprising 14 clinical and 4 cellular investigations. On the genetic level, pluripotent stem cells in humans and cardiomyocytes in mice displayed increased beat irregularity, with clinical studies revealing a persistent increase in heart rate after space travel. Further cardiovascular adaptations included a higher frequency of orthostatic tachycardia but no evidence of orthostatic hypotension, after return to sea level. Hemoglobin concentration was also consistently decreased after return to Earth. No consistent change in systolic or diastolic blood pressure or any clinically significant arrhythmias were observed during or after space travel.
CONCLUSION
Changes in oxygen carrying capacity, blood pressure, and post-flight orthostatic tachycardia may serve as reasons to further screen for pre-existing anemic and hypotensive conditions among astronauts.
Topics: Humans; Animals; Mice; Space Flight; Astronauts; Heart; Blood Pressure; Tachycardia
PubMed: 37302388
DOI: 10.1159/000531466 -
JAMA Network Open Apr 2024The associations of sodium glucose cotransporter-2 inhibitors (SGLT2is) with reduction in mortality and hospitalization rates in patients with heart failure (HF) are... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
The associations of sodium glucose cotransporter-2 inhibitors (SGLT2is) with reduction in mortality and hospitalization rates in patients with heart failure (HF) are well established. However, their association with improving functional capacity and quality of life (QOL) has been variably studied and less reported.
OBJECTIVE
To provide evidence on the extent to which SGLT2is are associated with improvement on objective measures of functional capacity and QOL in patients living with HF.
DATA SOURCES
The MEDLINE, EMBASE, and Cochrane databases were systematically searched for relevant articles on July 31, 2023.
STUDY SELECTION
Randomized, placebo-controlled clinical trials reporting the effect of SGLT2i on functional outcomes of exercise capacity (peak oxygen consumption [peak VO2] or 6-minute walk distance [6MWD]) and/or QOL using validated questionnaires for patients with HF were included.
DATA EXTRACTION AND SYNTHESIS
Data were extracted by 2 authors following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, and a meta-analysis using the restricted maximum likelihood random-effects model was conducted.
MAIN OUTCOMES AND MEASURES
Outcomes of interest included changes in peak VO2, 6MWD, and Kansas City Cardiomyopathy Questionnaire-12 total symptom score (KCCQ-TSS), clinical summary score (KCCQ-CSS), and overall summary score (KCCQ-OSS).
RESULTS
In this meta-analysis of 17 studies, 23 523 patients (mean [range] age, 69 [60-75] years) were followed over a period ranging from 12 to 52 weeks. Four studies included peak VO2 as an outcome, 7 studies included 6MWD, and 10 studies reported KCCQ scores. Mean (SD) left ventricular ejection fraction was 43.5% (12.4%). Compared with controls, patients receiving SGLT2i treatment experienced significant increases in peak VO2 (mean difference [MD], 1.61 mL/kg/min; 95% CI, 0.59-2.63 mL/kg/min; P = .002) and 6MWD (MD, 13.09 m; 95% CI, 1.20-24.97 m; P = .03). SGLT2i use was associated with increased KCCQ-TSS (MD, 2.28 points; 95% CI, 1.74-2.81 points; P < .001), KCCQ-CSS (MD, 2.14 points; 95% CI, 1.53-2.74 points; P < .001), and KCCQ-OSS (MD, 1.90 points; 95% CI, 1.41-2.39 points; P < .001) scores. Subgroup analysis and meta-regression demonstrated almost all improvements were consistent across ejection fraction, sex, and the presence of diabetes.
CONCLUSIONS AND RELEVANCE
These findings suggest that in addition to known clinical associations with mortality and hospitalization outcomes, SGLT2i use is associated with improvement in outcomes of interest to patients' everyday lives as measured by objective assessments of maximal exercise capacity and validated QOL questionnaires, regardless of sex or ejection fraction.
Topics: Aged; Humans; Heart Failure; Quality of Life; Sodium-Glucose Transporter 2 Inhibitors; Stroke Volume; Ventricular Function, Left; Middle Aged
PubMed: 38573633
DOI: 10.1001/jamanetworkopen.2024.5135 -
Nature and Science of Sleep 2021Obstructive sleep apnea (OSA) is a highly prevalent disease with substantial public health burden. In most of the cases, there is a genetic predisposition to OSA.... (Review)
Review
Polymorphism of the Serotonin Transporter Gene and the Peripheral 5-Hydroxytryptamine in Obstructive Sleep Apnea: What Do We Know and What are We Looking for? A Systematic Review of the Literature.
BACKGROUND
Obstructive sleep apnea (OSA) is a highly prevalent disease with substantial public health burden. In most of the cases, there is a genetic predisposition to OSA. Serotonin/T-HydroxyTriptamine (5-HT) plays a key role in ventilatory stimulation, while the polymorphism of the serotonin transporter gene (STG) leads to alterations in serotonin level, making it important in OSA.
OBJECTIVE
To examine whether the 5-HydroxyTriptamine and the genetic predisposition influence the incidence and evolution of OSA, we reviewed randomized, controlled trials and observational studies on the selected topic. The secondary objective was to determine the metabolic effects of the circulating serotonin in other tissues (liver, pancreas, gut, brown adipose tissue, and white adipose tissue) and its role in the development of obesity.
DATA SOURCES
A systematic review of English articles was performed based on PubMed and the Cochrane Library databases. Search filters included randomized controlled trial, controlled clinical trial, random allocation, double-blind method, and case-control studies and used the following keywords: Brain Serotonin OR Serotonin Transporter Gene Polymorphism OR Peripheral 5-HydroxyTryptamine AND Obstructive Sleep Apnea OR Sleep Disorder Breathing OR brain serotonin AND OSA OR serotonin transporter gene OR Peripheral 5-Hydroxytryptamine AND Sleep.
STUDY ELIGIBILITY CRITERIA
The inclusion criteria for the current review were previous diagnosis of OSA, age above 18 years, and articles including quantitative data about serotonin transporter gene or peripheral serotonin. Language and time criteria were added - English articles published in the last 15 years. Studies that were not included were reviews and case reports.
STUDY APPRAISAL AND SYNTHESIS METHODS
In order to study the serotonin function, a literature research was conducted in the databases Pubmed and Cochrane Library. The following search terms were used: serotonin, 5-hydroxytryptamine, serotonin transporter gene. A critical appraisal of the included studies was performed with the Newcastle-Ottawa scale (NOS) and Delphi list.
RESULTS
The search yielded 1210 articles, from which 43 were included. The included studies suggest that the two polymorphisms of serotonin transporter gene (5HTT) - variable number of tandem repeats (VNTR) and linked polymorphic region (LPR) - are strong candidates in the pathogenesis of OSA. The allele 10 of 5HTTVNTR and the long/long (L/L) allele genotype were associated with a higher prevalence of OSA and the L allele with a higher apnea-hypopnea index and a longer time during sleep with oxygen desaturation.
LIMITATIONS
The main limitation of the present study consists of heterogeneity of the information. Being a less studied subject, randomized trials are not widely available and most data were obtained from case-control trials. Moreover, the included material indirectly approached the subject by demonstrating the effects of serotoninergic system over the metabolism, the connection between serotonin and obesity, factors which are implied in the pathogenesis of OSA.
CONCLUSION AND IMPLICATIONS OF KEY FINDINGS
The two polymorphisms of serotonin gene can be considered important factors in the diagnosis and management of OSA.
PubMed: 33603523
DOI: 10.2147/NSS.S278170 -
Journal of Cardiothoracic and Vascular... Jul 2023This systematic review and meta-analysis aimed to investigate the role of regional cerebral oxygen saturation (rSO) in predicting survival and neurologic outcomes after... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This systematic review and meta-analysis aimed to investigate the role of regional cerebral oxygen saturation (rSO) in predicting survival and neurologic outcomes after extracorporeal cardiopulmonary resuscitation (ECPR).
DESIGN
The study authors performed a systematic review and meta-analysis of all available literature.
SETTING
The authors searched relevant databases (Pubmed, Medline, Embase) for studies measuring precannulation rSO in patients undergoing ECPR and reporting mortality and/or neurologic outcomes.
PARTICIPANTS
The authors included both in-hospital and out-of-hospital cardiac arrest patients receiving ECPR. They identified 3 observational studies, including 245 adult patients.
INTERVENTIONS
The authors compared patients with a low precannulation rSO (≤15% or 16%) versus patients with a high (>15% or 16%) precannulation rSO. In addition, the authors carried out subgroup analyses on out-of-hospital cardiac arrest (OHCA) patients.
MEASUREMENTS AND MAIN RESULTS
A high precannulation rSO was associated with an overall reduced risk of mortality in ECPR recipients (98 out of 151 patients [64.9%] in the high rSO group, v 87 out of 94 patients [92.5%] in the low rSO group, risk differences [RD] -0.30; 95% CI -0.47 to -0.14), and in OHCA (78 out of 121 patients [64.5%] v 82 out of 89 patients [92.1%], RD 0.30; 95% CI -0.48 to -0.12). A high precannulation rSO also was associated with a significantly better neurologic outcome in the overall population (42 out of 151 patients [27.8%] v 2 out of 94 patients [2.12%], RD 0.22; 95% CI 0.13-0.31), and in OHCA patients (33 out of 121 patients [27.3%] v 2 out of 89 patients [2.25%] RD 0.21; 95% CI 0.11-0.30).
CONCLUSIONS
A low rSO before starting ECPR could be a predictor of mortality and survival with poor neurologic outcomes.
Topics: Adult; Humans; Out-of-Hospital Cardiac Arrest; Oxygen Saturation; Cardiopulmonary Resuscitation; Pulmonary Gas Exchange; Hospitals; Retrospective Studies
PubMed: 36759264
DOI: 10.1053/j.jvca.2023.01.007 -
Revista Brasileira de Terapia Intensiva 2021Red blood cell transfusion is thought to improve cell respiration during septic shock. Nevertheless, its acute impact on oxygen transport and metabolism in this... (Meta-Analysis)
Meta-Analysis
Red blood cell transfusion is thought to improve cell respiration during septic shock. Nevertheless, its acute impact on oxygen transport and metabolism in this condition remains highly debatable. The objective of this study was to evaluate the impact of red blood cell transfusion on microcirculation and oxygen metabolism in patients with sepsis and septic shock. We conducted a search in the MEDLINE®, Elsevier and Scopus databases. We included studies conducted in adult humans with sepsis and septic shock. A systematic review and meta-analysis were performed using the DerSimonian and Laird random-effects model. A p value < 0.05 was considered significant. Nineteen manuscripts with 428 patients were included in the analysis. Red blood cell transfusions were associated with an increase in the pooled mean venous oxygen saturation of 3.7% (p < 0.001), a decrease in oxygen extraction ratio of -6.98 (p < 0.001) and had no significant effect on the cardiac index (0.02L/minute; p = 0,96). Similar results were obtained in studies including simultaneous measurements of venous oxygen saturation, oxygen extraction ratio, and cardiac index. Red blood cell transfusions led to a significant increase in the proportion of perfused small vessels (2.85%; p = 0.553), while tissue oxygenation parameters revealed a significant increase in the tissue hemoglobin index (1.66; p = 0.018). Individual studies reported significant improvements in tissue oxygenation and sublingual microcirculatory parameters in patients with deranged microcirculation at baseline. Red blood cell transfusions seemed to improve systemic oxygen metabolism with apparent independence from cardiac index variations. Some beneficial effects have been observed for tissue oxygenation and microcirculation parameters, particularly in patients with more severe alterations at baseline. More studies are necessary to evaluate their clinical impact and to individualize transfusion decisions.
Topics: Erythrocyte Transfusion; Humans; Microcirculation; Oxygen; Sepsis; Shock, Septic
PubMed: 33886865
DOI: 10.5935/0103-507X.20210017 -
The Journal of Prosthetic Dentistry Jun 2023Titanium dental implants produced by additive manufacturing have pores that, depending on their size and quantity, may improve osteogenic cell adhesion without impairing... (Review)
Review
STATEMENT OF PROBLEM
Titanium dental implants produced by additive manufacturing have pores that, depending on their size and quantity, may improve osteogenic cell adhesion without impairing mechanical properties. A systematic review of in vitro studies on this topic is lacking.
PURPOSE
The purpose of this systematic review was to answer the question "What is the influence of pores on osteogenic cell adhesion on titanium surfaces produced by additive manufacturing?".
MATERIAL AND METHODS
The study was designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 standards and registered in the Open Science Framework (OSF) (osf.io/baw59). A manual search of published articles without language or time restrictions was conducted in November 2022 in the electronic databases PubMed, Scopus, ScienceDirect, Embase, and in the nonpeer-reviewed literature via Google Scholar.
RESULTS
A total of 1338 initial results were found, and after removing duplicates and applying eligibility criteria, 13 articles were included in this review that, according to the Joanna Briggs Institute (JBI) tool, presented a low risk of bias. Pores with larger diameters provide greater a surface area that favors cell filopodia adhesion and has interconnection that optimizes the transport of nutrients and oxygen and bone cell activity.
CONCLUSIONS
The presence of pores on the surface of titanium produced by additive manufacturing increases the adhesion, migration, proliferation, and viability of osteogenic cells.
PubMed: 37353409
DOI: 10.1016/j.prosdent.2023.05.010 -
Journal of Toxicology 2020Iron is an essential element and the most abundant trace metal in the body involved in oxygen transport and oxygen sensing, electron transfer, energy metabolism, and DNA... (Review)
Review
Iron is an essential element and the most abundant trace metal in the body involved in oxygen transport and oxygen sensing, electron transfer, energy metabolism, and DNA synthesis. Excess labile and unchelated iron can catalyze the formation of tissue-damaging radicals and induce oxidative stress. English abstracts were identified in PubMed and Google Scholar using multiple and various search terms based on defined inclusion and exclusion criteria. Full-length articles were selected for systematic review, and secondary and tertiary references were developed. Although bloodletting or phlebotomy remains the gold standard in the management of iron overload, this systematic review is an updated account of the pitfalls of phlebotomy and classical synthetic chelators with scientific justification for the use of natural iron chelators of dietary origin in resource-poor nations.
PubMed: 32399029
DOI: 10.1155/2020/4084538 -
The Science of the Total Environment Jan 2024Low- and middle-income countries (LMIC) are disproportionately affected by air pollution and its health burden, representing a global inequity. The COVID-19 pandemic... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Low- and middle-income countries (LMIC) are disproportionately affected by air pollution and its health burden, representing a global inequity. The COVID-19 pandemic provided a unique opportunity to investigate the impact of unprecedented lockdown measures on air pollutant concentrations globally. We aim to quantify air pollutant concentration changes across LMIC settings as a result of COVID-19 restrictions.
METHODS
Searches for this systematic review and meta-analysis were carried out across five databases on 30th March 2022; MEDLINE, Embase, Web of Science, Scopus and Transport Research Information Documentation. Modelling and observational studies were included, as long as the estimates reflected city or town level data and were taken exclusively in pre-lockdown and lockdown periods. Mean percentage changes per pollutant were calculated and meta-analyses were carried out to calculate mean difference in measured ground-level observed concentrations for each pollutant (PROSPERO CRD42022326924).
FINDINGS
Of the 2982 manuscripts from initial searches, 256 manuscripts were included providing 3818 percentage changes of all pollutants. No studies included any countries from Sub-Saharan Africa and 34 % and 39.4 % of studies were from China and India, respectively. There was a mean percentage change of -37.4 %, -21.7 %, -54.6 %, -39.1 %, -48.9 %, 16.9 %, -34.9 %, -30.6 % and - 14.7 % for black carbon (BC), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO), oxides of nitrogen (NO), ozone (O), particulate matter 10 (PM) and 2.5 (PM) and sulphur dioxide (SO), respectively. Meta-analysis included 100 manuscripts, providing 908 mean concentration differences, which showed significant reduction in mean concentration in all study settings for BC (-0.46 μg/m, PI -0.85; -0.08), CO (-0.25 mg/m, PI -0.44; -0.03), NO (-19.41 μg/m, PI -31.14; -7.68) and NO (-22.32 μg/m, PI -40.94; -3.70).
INTERPRETATION
The findings of this systematic review and meta-analysis quantify and confirm the trends reported across the globe in air pollutant concentration, including increases in O. Despite the majority of global urban growth occurring in LMIC, there are distinct geographical gaps in air pollution data and, where it is available, differing approaches to analysis and reporting.
Topics: Humans; Developing Countries; Nitrogen Dioxide; Pandemics; COVID-19; Communicable Disease Control; Air Pollution; Air Pollutants; Particulate Matter; Ozone; Nitric Oxide
PubMed: 37884141
DOI: 10.1016/j.scitotenv.2023.168110 -
Frontiers in Physiology 2023A training program can stimulate physiological, anatomical, and performance adaptations, but these improvements can be partially or entirely reversed due to the...
A training program can stimulate physiological, anatomical, and performance adaptations, but these improvements can be partially or entirely reversed due to the cessation of habitual physical activity resulting from illness, injury, or other influencing factors. To investigate the effects of detraining on cardiorespiratory, metabolic, hormonal, muscular adaptations, as well as short-term and long-term performance changes in endurance athletes. Eligible studies were sourced from databases and the library up until July 2023. Included studies considered endurance athletes as subjects and reported on detraining duration. Total cessation of training leads to a decrease in VOmax due to reductions in both blood and plasma volume. Cardiac changes include decreases in left ventricular mass, size, and thickness, along with an increase in heart rate and blood pressure, ultimately resulting in reduced cardiac output and impaired performance. Metabolically, there are declines in lactate threshold and muscle glycogen, increased body weight, altered respiratory exchange ratio, and changes in power parameters. In the short term, there is a decrease in insulin sensitivity, while glucagon, growth hormone, and cortisol levels remain unchanged. Skeletal muscle experiences reductions in arterial-venous oxygen difference and glucose transporter-4. Implementing a partial reduction in training may help mitigate drastic losses in physiological and performance parameters, a consideration when transitioning between training seasons. There is a dearth of data investigating the detraining effects of training reduction/cessation among endurance athletes. Delving deeper into this topic may be useful for professionals and researchers to identify the optimal strategies to minimize these effects.
PubMed: 38344385
DOI: 10.3389/fphys.2023.1334766 -
Antioxidants (Basel, Switzerland) Feb 2022Mitochondrial uncoupling proteins (UCP) 1-3 fulfill many physiological functions, ranging from non-shivering thermogenesis (UCP1) to glucose-stimulated insulin release... (Review)
Review
Mitochondrial uncoupling proteins (UCP) 1-3 fulfill many physiological functions, ranging from non-shivering thermogenesis (UCP1) to glucose-stimulated insulin release (GSIS) and satiety signaling (UCP2) and muscle fuel metabolism (UCP3). Several studies have suggested that UCPs mediate these functions by facilitating proton return to the matrix. This would decrease protonic backpressure on the respiratory chain, lowering the production of hydrogen peroxide (HO), a second messenger. However, controlling mitochondrial HO production to prevent oxidative stress by activating these leaks through these proteins is still enthusiastically debated. This is due to compelling evidence that UCP2/3 fulfill other function(s) and the inability to reproduce findings that UCP1-3 use inducible leaks to control reactive oxygen species (ROS) production. Further, other studies have found that UCP2/3 may serve as Ca. Therefore, we performed a systematic review aiming to summarize the results collected on the topic. A literature search using a list of curated keywords in Pubmed, BIOSIS Citation Index and Scopus was conducted. Potentially relevant references were screened, duplicate references eliminated, and then literature titles and abstracts were evaluated using Rayyan software. A total of 1101 eligible studies were identified for the review. From this total, 416 studies were evaluated based on our inclusion criteria. In general, most studies identified a role for UCPs in preventing oxidative stress, and in some cases, this may be related to the induction of leaks and lowering protonic backpressure on the respiratory chain. However, some studies also generated evidence that UCP2/3 may mitigate oxidative stress by transporting Ca into the matrix, exporting lipid hydroperoxides, or by transporting C-4 metabolites. Additionally, some showed that activating UCP1 or 3 can increase mitochondrial ROS production, even though there is still augmented protection from oxidative stress. : Overall, most available studies demonstrate that UCPs, particularly UCP2/3, prevent oxidative stress. However, the mechanism utilized to do so remains elusive and raises the question that UCP2/3 should be renamed, since they may still not be true "uncoupling proteins".
PubMed: 35204205
DOI: 10.3390/antiox11020322