Loss of YhcB results in dysregulation of coordinated peptidoglycan, LPS and phospholipid synthesis during Escherichia coli cell growth.

The cell envelope is essential for viability in all domains of life. It retains enzymes and substrates within a confined space while providing a protective barrier to the external environment. Destabilising the envelope of bacterial pathogens is a common strategy employed by antimicrobial treatment. However, even in one of the best studied organisms, Escherichia coli, there remain gaps in our understanding of how the synthesis of the successive layers of the cell envelope are coordinated during growth and cell division. Here, we used a whole-genome phenotypic screen to identify mutants with a defective cell envelope. We report that loss of yhcB, a conserved gene of unknown function, results in loss of envelope stability, increased cell permeability and dysregulated control of cell size. Using whole genome transposon mutagenesis strategies, we report the comprehensive genetic interaction network of yhcB, revealing all genes with a synthetic negative and a synthetic positive relationship. These genes include those previously reported to have a role in cell envelope biogenesis. Surprisingly, we identified genes previously annotated as essential that became non-essential in a ΔyhcB background. Subsequent analyses suggest that YhcB functions at the junction of several envelope biosynthetic pathways coordinating the spatiotemporal growth of the cell, highlighting YhcB as an as yet unexplored antimicrobial target.

External Loads of Elite Soccer Referees: A Systematic Review with meta-analysis.

The objective of the present study was to describe the total and fragmented external loads, at different intensities, of soccer referees in European and South American competitions during official matches through a systematic review and meta-analysis of cross-sectional studies. A systematic review was conducted in April, 2020. In all, 32 studies were included, incorporating 578 referees evaluated in 3170 games through video analysis or a global positioning system. Regarding external loads, it was observed that the total average distance covered by the referees was 10,461.74 m, with running speeds predominantly below 13 km.h-1. The total distance covered by the referees in the European competitions was higher and more intense than that of the referees in the South American tournaments, being 11,187.02 m and 9319.61 m, respectively. We suggest that referees' training can be organized according to the distances found at different intensities, in which low-intensity races can be performed below 13 km.h-1 with distances of approximately 4500 m, while high-intensity training can be developed with speeds from 18 to 24 km.h-1 for approximately 800 m. In addition, planning must consider the competition characteristics.

Quantifying physiological and biomechanical responses of shallow water walking: a systematic review and meta-analysis.

Detecting the physiological and biomechanical alterations in shallow water walking (SWW) due to water depth and speed is important for health professionals to perform accurate exercise prescription. This systematic review with meta-analysis aimed to investigate the acute physiological and biomechanical responses of SWW at different immersion depths in comparison to dry land walking. The main result (initial search: 1960 studies; systematic review: 42 studies; meta-analysis: 22 studies) indicated that metabolic power was higher in the immersion depth levels of xiphoid process (standardized mean differences (SMD) = 0.90; 95% confidence intervals (CI): 0.26 to 1.54) and waist (SMD = 3.35; 95% CI: -0.18 to 6.87) in comparison to dry land. SWW at xiphoid and waist depths seems to be an adequate exercise if the objective is to increase the energy expenditure and cardiovascular demand while the lower limb impact forces are reduced in comparison to dry land walking. PROSPERO registration: CRD42018113040.

Chronic aerobic exercise prevents high-fructose diet-induced impairment in blood pressure in healthy young adults: a double-blind, randomised clinical trial.

The purpose of the study was to verify the effect of 4 weeks of a high-fructose diet (HFD) associated with aerobic training on the risk factors for cardiometabolic diseases. Twenty-one young adults were randomised into three groups: HFD (HFD: 1 g/kg body weight of fructose/day), high-glucose diet (HGD: 1 g/kg body weight of glucose/day) and high-fructose diet and exercise (HFDE: 1 g/kg body weight of fructose/day + 3 weekly 60-minute sessions of aerobic exercise). Before and after the 4 weeks of the intervention, blood samples were taken and flow-mediated dilatation, insulin resistance index, pancreatic beta cell functional capacity index, insulin sensitivity index and 24-h blood pressure were evaluated. HFD showed an increase in uric acid concentrations (P = 0·040), and HGD and HFDE groups showed no changes in this outcome between pre- and post-intervention; however, the HFDE group showed increased uric acid concentrations from the middle to the end of the intervention (P = 0·013). In addition, the HFD group showed increases in nocturnal systolic blood pressure (SBP) (P = 0·022) and nocturnal diastolic blood pressure (DBP) (P = 0·009). The HGD group exhibited decreases in nocturnal SBP (P = 0·028) and nocturnal DBP (P = 0·031), and the HFDE group showed a decrease in 24-h SBP (P = 0·018). The consumption of 1 g/kg of fructose per day may increase uric acid concentrations and blood pressure in adults. Additionally, aerobic exercises along with fructose consumption attenuate changes in uric acid concentrations and prevent impairment in nocturnal blood pressure.

Cardiometabolic health profile of young girls with aesthetic professions.

BACKGROUND: In the literature, professions that impose body standards for daily performance are designated as non-conventional professions (i.e. models, athletes, ballet dancers), with great emphasis on the female population. More than a job, it becomes a lifestyle to those inserted in this environment, thus, thousands of children and adolescents seek inclusion and success in these professions due to financial and media gains. Such professions are associated with several health-related risk factors. The purpose of this study was to identify and compare among physical fitness levels, cardiometabolic health markers, mental health and dietary habits in non-conventional professions. METHODS: The sample consisted of 41 female individuals aged between 14 and 24 years, allocated into four groups, control group composed by university students (UG = 11), models (MG = 11), ballet dancers (BG = 11), and athletes' group (AG = 8). Physical fitness outcomes (cardiorespiratory fitness, flexibility, maximal dynamic strength, muscular endurance and body composition); biochemical outcomes (high-density lipoprotein [HDL], low-density lipoprotein [LDL], total cholesterol [TC], fasting glucose [FG], fasting insulin [FI], C-reactive protein [CRP]), diet quality and mental health were evaluated. RESULTS: No impairments were observed in the health markers evaluated among groups, both for health-related physical fitness and biochemical outcomes. However, low levels of bone mineral density (BMD) were observed. Even with statistically significant differences between the groups for chronological age (p = 0.002), menarche (p = 0.004), career length (p = 0.001), height (p = 0.001), body mass index (p = 0.018), waist-to-height ratio (p < 0.001), %Fat (p = 0.020), VO2peak (p = 0.020), maximal dynamic strength of knee extensors (p = 0.031) and elbow flexors (p = 0,001) and flexibility (p < 0.001), all these values are within the normal range for health. CONCLUSION: The professions analyzed do not seem to interfere in the physical fitness and cardiometabolic health of the girls assessed. However, we identified that exposure to these profession can impair mental health (depressive symptoms in 100% of participants) and body composition (BMD 63% of participants).

Mathematical models to identify high-performance players for the Brazilian under-19 men's volleyball team.

The objective of this study was to identify parameters that best discriminate between selected and non-selected players for the Brazilian under-19 men's volleyball team and propose mathematical models to identify high-performance players. To this end, 18 selected (16.89±0.96 years) and 138 non-selected (16.91±0.74 years) players for the under-19 team were assessed for the training profile, anthropometric profile, and physical performance level. The discriminant function analysis was used to build the models, with a significance of α<0.05. The spike jump reach showed a greater correlation with the discriminant scores obtained in the two models (r=0.701; r=0.782). The 10 variables included in Model 1 helped identify 88.9% of the players selected in their group of origin; Model 2 - obtained by the spike jump reach and duration of playing experience - identified 83.3% of the players selected. Therefore, coaches should be aware that differences between the selected and non-selected players are multi-factorial, with the spike jump reach being the most relevant assessment factor. Furthermore, good players for the selection can be identified using the two models: Model 1 promises greater success with ten assessments, whereas Model 2 allows the identification of suitable players for the under-19 men's volleyball team with only two simple assessments.

Correlations Between Jump Performance in Block and Attack and the Performance in Official Games, Squat Jumps, and Countermovement Jumps of Professional Volleyball Players.

ABSTRACT: Berriel, GP, Schons, P, Costa, RR, Oses, VHS, Fischer, G, Pantoja, PD, Kruel, LFM, and Peyré-Tartaruga, LA. Correlations between jump performance in block and attack and the performance in official games, squat jumps, and countermovement jumps of professional volleyball players. J Strength Cond Res 35(12S): S64-S69, 2021-The jump used in performance tests must be chosen according to the specificity. The aims of the present study were to analyze the correlations between height and reach of block and attack jumps and the effectiveness of such actions in official games and also the relationship between height and reach of attack and block jumps and the height achieved in squat jump (SJ), countermovement jump (CMJ), and CMJ with an arms swing (CMJA). Thirteen, male, professional volleyball players who competed in the Brazilian Volleyball Super League participated in this study. Evaluations of height and reach of attack and block jumps and height of SJ, CMJ, and CMJA were performed. Attack and block effectiveness were evaluated in 8 official games. Pearson's product-moment correlation coefficient was used, and the significance level was set at α ≤ 0.05. Attack jump height correlated with attack effectiveness in the games (r = 0.57; p = 0.05). Block jump height presented a very large correlation with SJ height (r = 0.82; p < 0.01), and attack jump height presented a very large correlation with CMJ height (r = 0.86; p < 0.01). Success in attack actions is directly associated with the athlete's ability to perform a vertical jump. Moreover, SJ, CMJ, and CMJA tests provided information of great applicability for the volleyball players' needs. Because of the relevance of the results, these tests should be included in the assessment routine of professional volleyball players.

Effect of different physical training modalities on peak oxygen consumptions in post-acute myocardial infarction patients: systematic review and meta-analysis.

Physical training can increase peak oxygen uptake (VO2peak) in people who have suffered acute myocardial infarction (AMI). However, there is still a gap in the literature in relation to the effectiveness of different types of interventions. Therefore, the aim of the present study was to evaluate the effects of different physical training modalities on VO2peak in post-AMI patients. The following databases were used: PubMed (MEDLINE), Cochrane Library, Scopus, and Pedro. Studies that evaluated aerobic exercise, strength exercise, or combined exercise were included. Six studies met eligibility criteria. Aerobic exercise increased VO2peak by 6.07 ml.kg-1.min-1 when compared to the control group (CG) (p = 0.013). The comparison between combined exercise and control group detected a difference of 1.84 ml.kg-1.min-1, but this was not significant (p = 0.312). We therefore conclude that aerobic exercise is the only modality that is effective for increasing VO2peak compared to a control group.

Interplay of cold shock protein E with an uncharacterized protein, YciF, lowers porin expression and enhances bile resistance in Salmonella Typhimurium.

Bacterial cold shock proteins (CSPs) function as RNA chaperones. To assess CSP's roles in the intracellular human pathogen Salmonella Typhimurium, we analyzed their expression in varied stress conditions. We found that cold shock protein E (cspE or STM14_0732) is up-regulated during bile salt-induced stress and that an S. Typhimurium strain lacking cspE (ΔcspE) displays dose-dependent sensitivity to bile salts, specifically to deoxycholate. We also found that an uncharacterized gene, yciF (STM14_2092), is up-regulated in response to bile stress in WT but not in the ΔcspE strain. Complementation with WT CspE, but not with a F30V CspE variant, abrogated the bile sensitivity of ΔcspE as did multicopy overexpression of yciF. Northern blotting experiments with rifampicin disclosed that the regulation of yciF expression is, most likely, due to the RNA-stabilizing activity of CspE. Importantly, electrophoretic mobility shift assays indicated that purified CspE, but not the F30V variant, directly binds yciF mRNA. We also observed that the extra-cytoplasmic stress-response (ESR) pathway is augmented in the bile-treated ΔcspE strain, as judged by induction of RpoE regulon genes (rpoE, degP, and rybB) and downstream ESR genes (hfq, rne, and PNPase). Moreover, the transcript levels of the porin genes, ompD, ompF, and ompC, were higher in bile salts-stressed ΔcspE and correlated with higher intracellular accumulation of the fluorescent DNA stain bisBenzimide H 33258, indicating greater cell permeability. In conclusion, our study has identified YciF, a CspE target involved in the regulation of porins and in countering bile stress in S. Typhimurium.

Salmonella Typhimurium encoded cold shock protein E is essential for motility and biofilm formation.

The ability of bacteria to form biofilms increases their survival under adverse environmental conditions. Biofilms have enormous medical and environmental impact; consequently, the factors that influence biofilm formation are an important area of study. In this investigation, the roles of two cold shock proteins (CSP) during biofilm formation were investigated in Salmonella Typhimurium, which is a major foodborne pathogen. Among all CSP transcripts studied, the expression of cspE (STM14_0732) was higher during biofilm growth. The cspE deletion strain (ΔcspE) did not form biofilms on a cholesterol coated glass surface; however, complementation with WT cspE, but not the F30V mutant, was able to rescue this phenotype. Transcript levels of other CSPs demonstrated up-regulation of cspA (STM14_4399) in ΔcspE. The cspA deletion strain (ΔcspA) did not affect biofilm formation; however, ΔcspEΔcspA exhibited higher biofilm formation compared to ΔcspE. Most likely, the higher cspA amounts in ΔcspE reduced biofilm formation, which was corroborated using cspA over-expression studies. Further functional studies revealed that ΔcspE and ΔcspEΔcspA exhibited slow swimming but no swarming motility. Although cspA over-expression did not affect motility, cspE complementation restored the swarming motility of ΔcspE. The transcript levels of the major genes involved in motility in ΔcspE demonstrated lower expression of the class III (fliC, motA, cheY), but not class I (flhD) or class II (fliA, fliL), flagellar regulon genes. Overall, this study has identified the interplay of two CSPs in regulating two biological processes: CspE is essential for motility in a CspA-independent manner whereas biofilm formation is CspA-dependent.

Long-Term Effects of Three Water-Based Training Programs on Resting Blood Pressure in Older Women.

The aim of the study was to compare the effects of three water-based training on blood pressure (BP) in older women. A total of 57 participants were randomized into the following groups: (a) aerobic training (AT), (b) concurrent training in which resistance training progresses to the use of resistive equipment (CTRE), and (c) concurrent training in which resistance training progresses to multiple sets (CTMS). The participants trained twice a week for 16 weeks. Systolic BP decreased from pretraining to after 8 weeks of training and, subsequently, to after 16 weeks of training (AT: -6.53 mmHg, CTRE: -10.45 mmHg, and CTMS: -10.73 mmHg). Diastolic BP decreased from pretraining to after 8 and 16 weeks of training (AT: -6.23 mmHg, CTRE: -4.61 mmHg, and CTMS: -6.19 mmHg). Furthermore, 16% of the AT participants, 23% of the CTRE participants, and 28.5% of the CTMS participants were no longer classified as hypertensive. Water-based aerobic and concurrent training are efficient nonpharmacological measures to reduce BP in older women.

Effects of dance practice on functional mobility, motor symptoms and quality of life in people with Parkinson's disease: a systematic review with meta-analysis.

BACKGROUND: Patients with Parkinson's Disease (PD) undergo motor injuries, which decrease their quality of life (QL). Dance, added to drug therapy, can help treating these patients AIMS: To conduct a systematic review with meta-analysis with the aim to analyze the effects of dance classes in comparison to other interventions or to the absence of intervention, in randomized clinical trials (RCTs), on functional mobility, motor symptoms and QL of PD patients METHODS: The search was conducted in MEDLINE, LILACS, SciELO, Cochrane and PsycINFO (last searched in August 2017). RCTs analyzing dance effects in comparison to other physical training types or to no intervention, on functional mobility, motor symptoms and QL of PD patients were selected. The outcomes assessed were motor symptoms with Unified PD Rating Scale III (UPDRSIII), functional mobility with Timed Up and Go Test (TUG), endurance with 6 min walking test (6MWT), freezing of gait with Freezing of Gait Questionnaire (FOG_Q), walking velocity with GAITRite and QL with PD Questionnaire (PDQ39). Two reviewers independently extracted methodological quality and studies data. Results are presented as weighted mean differences. RESULTS: Five RCTs were included, totaling 159 patients. Dance promoted significant improvements on UPDRSIII, and a decrease in TUG time when compared to other types of exercise. In comparison to the absence of intervention, dance practice also showed significant improvements in motor scores. CONCLUSION: Dance can improve motor parameters of the disease and patients' functional mobility.

Acute glycemic and pressure responses of continuous and interval aerobic exercise in patients with type 2 diabetes.

BACKGROUND: Aerobic training has been widely indicated to patients with type 2 diabetes. However, there are still few studies comparing acute glycemic and blood pressure effects of different methods of aerobic training. The aim is to compare glycemic and pressure acute responses of continuous aerobic exercise to interval aerobic exercise in patients with type 2 diabetes. MATERIALS AND METHODS: This study is a randomized, crossover clinical trial. Fourteen patients with type 2 diabetes performed two sessions of aerobic training with different methods (continuous and interval). Continuous session had duration of 35 minutes with intensity of 85-90% of heart rate corresponding to anaerobic threshold (HRAT), while interval session had 45 minutes, with stimulus in intensity of 85-90% of HRAT with recovery in intensity under 85% of HRAT. Capillary glycemia, systolic and diastolic blood pressure were analyzed before and after the sessions. RESULTS: Patients were 63.5 ± 9.8 years old. Glycemia was reduced in both sessions (p < 0.001). Only glycemia measured at 25 minutes after continuous session was not lower than pre-session values. Systolic blood pressure was also reduced in both sessions (p = 0.010) with similar behavior between them. In the diastolic blood pressure, there were differences only between the values measured immediately after exercise and the values measured 20 minutes (p = 0.002) and 30 minutes after exercise (p = 0.008). CONCLUSION: Both continuous and interval aerobic exercise, in a same intensity, are effective for glycemic and pressure acute reductions in individuals with type 2 diabetes. For patients with greater risk of hypertension, we believe that the interval method is safer.

Effects of aerobic exercise performed in fasted v. fed state on fat and carbohydrate metabolism in adults: a systematic review and meta-analysis.

This study aimed to verify the effect of aerobic exercise performed in the fasted v. fed states on fat and carbohydrate metabolism in adults. Searches were conducted in March 2015, and updated in July 2016, using PubMed®, Scopus and Cochrane databases (terms: 'fasting', 'exercise', 'aerobic exercise', 'substrate', 'energy metabolism', 'fat', 'glucose', 'insulin' and 'adult') and references from selected studies. Trials that compared the metabolic effects of aerobic exercise (duration ≤120 min) performed in the fasted v. fed states in adults were accepted. The outcomes evaluated were fat oxidation during exercise and the plasma concentrations of insulin, glucose and NEFA before and immediately after exercise; two independent reviewers extracted the data (A. F. V. and L. C.). The results were presented as weighted mean differences between treatments, with 95 % CI. Of 10 405 articles identified, twenty-seven studies - with a total of 273 participants - were included. There was a significant increase in fat oxidation during exercise performed in the fasted, compared with fed, state (-3·08 g; 95 % CI -5·38, -0·79; I 2 39·1 %). The weighted mean difference of NEFA concentrations was not significantly different between states (0·00 mmol/l; 95 % CI -0·07, 0·08; I 2 72·7 %). However, the weighted mean differences of glucose (0·78 mmol/l; 95 % CI 0·43, 1·14; I 2 90·8 %) and insulin concentrations (104·5 pmol/l; 95 % CI 70·8, 138·2; I 2 94·5 %) were significantly higher for exercise performed in the fed state. We conclude that aerobic exercise performed in the fasted state induces higher fat oxidation than exercise performed in the fed state.

Type 5 secretion system antigens as vaccines against Gram-negative bacterial infections.

Infections caused by Gram-negative bacteria are leading causes of mortality worldwide. Due to the rise in antibiotic resistant strains, there is a desperate need for alternative strategies to control infections caused by these organisms. One such approach is the prevention of infection through vaccination. While live attenuated and heat-killed bacterial vaccines are effective, they can lead to adverse reactions. Newer vaccine technologies focus on utilizing polysaccharide or protein subunits for safer and more targeted vaccination approaches. One promising avenue in this regard is the use of proteins released by the Type 5 secretion system (T5SS). This system is the most prevalent secretion system in Gram-negative bacteria. These proteins are compelling vaccine candidates due to their demonstrated protective role in current licensed vaccines. Notably, Pertactin, FHA, and NadA are integral components of licensed vaccines designed to prevent infections caused by Bordetella pertussis or Neisseria meningitidis. In this review, we delve into the significance of incorporating T5SS proteins into licensed vaccines, their contributions to virulence, conserved structural motifs, and the protective immune responses elicited by these proteins.

Genome-wide fitness analysis of Salmonella enterica reveals aroA mutants are attenuated due to iron restriction in vitro.

Salmonella enterica is a globally disseminated pathogen that is the cause of over 100 million infections per year. The resulting diseases are dependent upon host susceptibility and the infecting serovar. As S. enterica serovar Typhimurium induces a typhoid-like disease in mice, this model has been used extensively to illuminate various aspects of Salmonella infection and host responses. Due to the severity of infection in this model, researchers often use strains of mice resistant to infection or attenuated Salmonella. Despite decades of research, many aspects of Salmonella infection and fundamental biology remain poorly understood. Here, we use a transposon insertion sequencing technique to interrogate the essential genomes of widely used isogenic wild-type and attenuated S. Typhimurium strains. We reveal differential essential pathways between strains in vitro and provide a direct link between iron starvation, DNA synthesis, and bacterial membrane integrity.IMPORTANCESalmonella enterica is an important clinical pathogen that causes a high number of deaths and is increasingly resistant to antibiotics. Importantly, S. enterica is used widely as a model to understand host responses to infection. Understanding how Salmonella survives in vivo is important for the design of new vaccines to combat this pathogen. Live attenuated vaccines have been used clinically for decades. A widely used mutation, aroA, is thought to attenuate Salmonella by restricting the ability of the bacterium to access particular amino acids. Here we show that this mutation limits the ability of Salmonella to acquire iron. These observations have implications for the interpretation of many previous studies and for the use of aroA in vaccine development.

Pro- and Anti-inflammatory Biomarkers Responses after Aerobic Training in Heart Transplant Recipients: A Systematic Review and Meta-analysis.

BACKGROUND: Physical exercise (PE) may improve plasma concentration of interleukin- 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and adiponectin (adpN) in heart transplant (HT) patients. However, no consistent data is available on this population. AIM: Thus, we aimed to conduct a systematic review and meta-analysis on the effects of PE over these pro- and anti-inflammatory biomarkers in HT patients. METHODS: Following the guidelines established by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement, we conducted a systematic literature search in the PubMed, Cochrane, and Scopus databases. Outcomes included IL-6, TNF-alpha, and adpN. Effect size (ES) was calculated using the standardized mean difference with a 95% confidence interval (CI). RESULTS: The PE group (aerobic modality) was associated with reduced IL-6 compared to the control group (ES: -0.53; 95% CI: -0.99 to -0.06 pg/mL; P = 0.026). However, the PE group did not show a significant effect on TNF-alpha and adpN levels (ES: -0.33; 95% CI: -0.79 to 0.13; P = 0.16 and ES: -0.20; 95% CI: -0.70 to 0.30 pg/mL; P = 0.444, respectively). CONCLUSION: PE is associated with IL-6 reductions, although TNF alpha and adpN did not change after this intervention in HT patients. Therefore, PE is an effective intervention to downregulate IL-6 in post-HT patients.

Are dose-response relationships of resistance training reliable to improve functional performance in frail and pre-frail older adults? A systematic review with meta-analysis and meta-regression of randomized controlled trials.

This systematic review with meta-analyses investigates the impact of resistance training (RT), using meta-regressions, on functional performance in frail and pre-frail adults aged ≥ 65 years to determine the key variables of RT. Ten randomized controlled trials involving 1303 participants were analyzed. Five studies assessed habitual walking speed (HWS), three studies evaluated performance in the timed-up-and-go test (TUG), three studies evaluated performance in the Short Physical Performance Battery (SPPB), and three studies assessed performance in the sit-to-stand test (STS). RT alone improved STS time and SPPB scores in frail and pre-frail older adults. RT improved STS performance (Effect Size (ES):- 0.536; 95% CI - 0.874 to - 0.199; p = .002) and led to a 2.261-point increase in SPPB performance (ES:1.682; 95% CI 0.579-2.786; p = .003). At least two weekly training sessions are required to increase SPPB scores, and three sessions seem to optimize the improvements. Higher training volume per exercise and volume per session reduce the gains in SPPB performance. We did not observe any association between different doses of RT and STS time improvements. RT alone positively influenced TUG performance only in community-dwelling older frail and pre-frail adults but not in institutionalized older individuals. RT alone did not improve the HWS compared to the non-active control group.

Non-Invasive Assessment of Cardiodynamics by Impedance Cardiography during the Six-Minute Walk Test in Patients with Heart Failure. / Avaliação Cardiodinâmica Não Invasiva por Cardiografia de Impedância durante o Teste de Caminhada de Seis Minutos em Pacientes com Insuficiência Cardíaca.

BACKGROUND: Central Illustration: Non-Invasive Assessment of Cardiodynamics by Impedance Cardiography during the Six-Minute Walk Test in Patients with Heart Failure. The six-minute walk test (6MWT) is commonly used to evaluate heart failure (HF) patients. However, several clinical factors can influence the distance walked in the test. Signal-morphology impedance cardiography (SM-ICG) is a useful tool to noninvasively assess hemodynamics. OBJECTIVE: This study aimed to compare cardiac output (CO), heart rate (HR), and stroke volume (SV) acceleration and deceleration responses to 6MWT in individuals with HF and reduced ejection fraction (HFrEF) and healthy controls. METHODS: This is a cross-sectional observational study. CO, HR, SV and cardiac index (CI) were evaluated before, during, and after the 6MWT assessed by SM-ICG. The level of significance adopted in the statistical analysis was 5%. RESULTS: Twenty-seven participants were included (13 HFrEF and 14 healthy controls). CO and HR acceleration significantly differed between groups (p<0.01; p=0.039, respectively). We found significant differences in SV, CO and CI between groups (p<0.01). Linear regression showed an impaired SV contribution to CO change in HFrEF group (22.9% versus 57.4%). CONCLUSION: The main finding of the study was that individuals with HFrEF showed lower CO and HR acceleration values during the submaximal exercise test compared to healthy controls. This may indicate an imbalance in the autonomic response to exercise in this condition.

FUNDAMENTO: Figura Central: Avaliação Cardiodinâmica Não Invasiva por Cardiografia de Impedância durante o Teste de Caminhada de Seis Minutos em Pacientes com Insuficiência Cardíaca. O Teste de Caminhada de seis Minutos (TC6M) é comumente usado para avaliar pacientes com insuficiência cardíaca. No entanto, vários fatores clínicos podem influenciar a distância percorrida pelos pacientes no teste. A cardiografia de impedância (CI) na avaliação morfológica é uma ferramenta útil para avaliar a hemodinâmica cardíaca de maneira não invasiva. OBJETIVO: Este estudo teve como objetivo comparar as respostas de aceleração e desaceleração do Débito Cardíaco (DC), da Frequência Cardíaca (FC), e do Volume Sistólico (VS) ao TC6M de indivíduos com insuficiência cardíaca e fração de ejeção reduzida (ICFEr) com as de controles sadios. MÉTODOS: Este é um estudo transversal observacional. O DC, a FC, o VS e o Índice Cardíaco (IC) foram avaliados antes, durante e após o TC6M por CI. O nível de significância adotado na análise estatística foi 5%. RESULTADOS: Foram incluídos 27 participantes (13 com ICFEr e 14 controles sadios). A aceleração do DC e da FC foi significativamente diferente entre os grupos (p<0,01 e p=0,039, respectivamente). Encontramos diferenças significativas no VS, no DC e no IC entre os grupos (p<0,01). A regressão linear mostrou uma contribuição deficiente do VS à mudança no DC no grupo com ICFEr (22,9% versus 57,4%). CONCLUSÃO: O principal resultado deste estudo foi o fato de que indivíduos com ICFEr apresentaram valores mais baixos de aceleração do DC e da FC durante o teste de exercício submáximo em comparação a controles sadios. Isso pode indicar um desequilíbrio na resposta autonômica ao exercício nessa condição.

High-intensity interval training reduces blood pressure in older adults: A systematic review and meta-analysis.

BACKGROUND/OBJECTIVES: The current systematic review and meta-analysis evaluated the effects of High-Intensity Interval Training (HIIT) on blood pressure (BP) in older adults and compared the efficacy of HIIT versus moderate-intensity continuous training (MICT). METHODS: Search was conducted using the databases at PubMed, Scopus, Cochrane Library and EMBASE, for randomized trials comparing the chronic effects (≥4 weeks) of HIIT versus MICT or control group (non-exercise) on BP in older adults (≥60 years) with or without hypertension. RESULTS: A total of 10 articles (n = 266 participants) were included in this meta-analysis. HIIT were associated with reductions in systolic BP (MD -7.36; 95%CI -11.80 to -2.92; P < 0.01; I2 = 24%) and diastolic BP (MD -5.48; 95%CI -8.71 to -2.25; P < 0.01; I2 = 40%) versus control group. No differences were found between HIIT and MICT in systolic BP (MD -2.09; 95%CI -9.76 to 5.58; P = 0.59; I2 = 0%) and diastolic BP (MD -1.00; 95%CI -6.01 to 4.01; P = 0.69; I2 = 0%). CONCLUSION: HIIT reduces BP in older adults. Additionally, HIIT and MICT provided comparable reductions on BP in this population.