Intramuscular vascular malformations in pediatric patients: a retrospective study in a vascular anomalies clinic.

BACKGROUND: Intramuscular vascular malformations (IVMs) are rare developmental congenital structural abnormalities. Their clinical diagnosis is difficult, and imaging studies are essential to determine the type and extent of vessels involved. Treatment can be challenging and must be managed by a multidisciplinary team. METHODS: A descriptive, observational, retrospective, longitudinal study of clinical records of patients diagnosed with IVMs who were evaluated at the vascular anomalies clinic from January 2011 to December 2021 was performed. Demographic, clinical, imaging, diagnosis, treatment, and response data were collected. RESULTS: Seven patients (five females and two males) with a mean age of 13.66 years (standard deviation 5.82 years) were included in the study. In all cases, the clinical diagnosis was venous and lymphatic malformation. The radiological findings were dilated and tortuous vascular structures or multilobulated lesions with septa inside, with or without vascular flow; these findings allowed diagnosis in all cases. Treatment modalities included sclerotherapy in five patients, surgical resection in two, medical treatment with sirolimus in three, and surveillance in one. Subsequent clinical evolution was favorable in all patients, with decreased pain in six (partial in four and total in two) and size reduction in one patient. CONCLUSION: IVMs in our pediatric population most frequently affect the lower extremities. The main symptoms and signs were pain on exertion and volume increase. Treatment can be challenging given the extension and depth of the malformations, so a combination of therapeutic modalities may be necessary to obtain the best outcome.

INTRODUCCIÓN: Las malformaciones vasculares intramusculares (MVI) son anomalías estructurales congénitas del desarrollo raras. Su diagnóstico clínico es difícil y los estudios de imagen son fundamentales para determinar su tipo y extensión. Su tratamiento puede ser un desafío y debe ser dirigido por un equipo multidisciplinario. MÉTODOS: Se realizó un estudio descriptivo, observacional, retrospectivo y longitudinal de los expedientes clínicos de pacientes con diagnóstico de MVI que fueron valorados en la Clínica de Anomalías Vasculares desde enero 2011 a diciembre 2021. Se recolectaron datos demográficos, clínicos, imagenológicos, diagnóstico, tratamiento y respuesta al mismo. RESULTADOS: Se incluyeron 7 pacientes (5 mujeres y 2 hombres) con una edad media de 13.66 años (DE 5.82 años). En todos, el diagnóstico clínico fue malformación venosa y/o linfática. Los hallazgos radiológicos mediante ultrasonido y/o resonancia magnética nuclear fueron estructuras vasculares dilatadas y tortuosas o lesiones multilobuladas con septos en su interior, con o sin flujo vascular; y en todos los casos permitieron hacer el diagnóstico. El tratamiento fue escleroterapia en 5 pacientes, resección quirúrgica en 2, tratamiento con Sirolimus en 3 y vigilancia en 1. La evolución clínica posterior fue favorable en todos, con disminución del dolor en 6 (parcial en 4 y total en 2) y reducción del tamaño en 1 paciente. CONCLUSIÓN: Las MVI en nuestra población pediátrica, afectan con mayor frecuencia las extremidades inferiores. Los principales síntomas fueron dolor de esfuerzo y aumento de volumen. Su tratamiento puede ser un reto dada su extensión y profundidad, por lo que la combinación de modalidades terapéuticas puede ser necesarias para obtener el mejor desenlace.

Tissue desaturation is not a major determinant of aging-related impairment in skeletal muscle reactive hyperemia: a retrospective analysis.

Near-infrared spectroscopy combined with vascular occlusion test (NIRS-VOT) is a reactive hyperemia technique for in vivo evaluation of skeletal muscle microvascular reactivity. Previous studies using NIRS-VOT have been shown to be able to detect impairments in microvascular function in high-risk cardiovascular disease populations, such as older individuals. It has been demonstrated that older individuals have slower reactive hyperemia compared with young individuals. Importantly, older individuals also show less desaturation during ischemia compared with young individuals. Based on these findings, it has been suggested that the slower reactive hyperemia observed in older individuals is explained by the lower desaturation during blood flow occlusion (reduced ischemic stimulus). This retrospective analysis compared reactive hyperemia in 36 young and 47 older tissue desaturation-matched individuals that underwent 5-min blood flow occlusion. Overall, we showed that older individuals have impaired reactive hyperemia compared with young when matching for the degree of desaturation and blood flow occlusion time. These findings provide evidence that lower tissue desaturation during ischemia is not a major determinant of impaired reactive hyperemia in older individuals.NEW & NOTEWORTHY Previous findings have suggested that aging-related impairment in skeletal muscle reactive hyperemia is majorly influenced by a lower degree of tissue desaturation during ischemia in older individuals compared with young individuals. In a retrospective analysis including 83 tissue desaturation-matched individuals, we show that the degree of tissue desaturation is not a major determinant of aging-related impairments in reactive hyperemia.

Aerobic Training With Blood Flow Restriction on Muscle Hypertrophy and Strength: Systematic Review and Meta-analysis.

ABSTRACT: de Lemos Muller, CH, Farinha, JB, Leal-Menezes, R, and Ramis, TR. Aerobic training with blood flow restriction on muscle hypertrophy and strength: systematic review and meta-analysis. J Strength Cond Res 38(7): 1341-1349, 2024-Integrating strength and endurance training in a single exercise session, even on separate days, can be physically demanding and time-consuming. Therefore, there is a growing interest in identifying efficient training methods that can concurrently enhance cardiovascular and neuromuscular performance through a singular training modality. This study conducted a systematic review and meta-analysis to explore the effects of aerobic training with blood flow restriction (AT + BFR) on muscle hypertrophy and strength gains in healthy individuals. Our study was registered at PROSPERO and used multiple databases (PubMed, Embase, Scopus, and Web of Science), seeking clinical trials that examined AT + BFR influence on muscle hypertrophy and strength gains in individuals aged 18-60 years and comparing with aerobic training without BFR. The risk of bias and method quality were assessed using the ROB2.0 tool and PEDro scale, respectively, and the quality of evidence was evaluated with the GRADE method. A random-effects model was used for meta-analysis, and standardized mean difference (SMD) was calculated for each outcome. Of 4,462 records, 29 full texts were assessed for eligibility, with 7 articles meeting the inclusion criteria. The results indicated that AT + BFR was more beneficial for inducing muscle hypertrophy than aerobic training without BFR (SMD [95% CI] = 0.86 [0.37-1.35]; I2 = 42%). Furthermore, AT + BFR was associated with greater improvements in muscle strength (SMD [95% CI] = 0.41 [0.10-0.72]; I2 = 0%). Despite the generally high risk of bias for both outcomes, these encouraging findings underscore the clinical significance of AT + BFR as a compelling tool for enhancing neuromuscular parameters.

Aerobic exercise training combined with local strength exercise restores muscle blood flow and maximal aerobic capacity in long-term Hodgkin lymphoma survivors.

It is unclear whether muscle blood flow (MBF) is altered in long-term Hodgkin lymphoma (HL) survivors. We tested the hypothesis that 1) MBF response during mental stress (MS) is impaired in long-term HL survivors and 2) aerobic exercise training combined with local strength exercise (ET) restores MBF responses during MS in these survivors. Eighteen 5-year HL survivors and 10 aged-paired healthy subjects (HC) were studied. Twenty HL survivors were randomly divided into two groups: exercise-trained (HLT, n = 10) and untrained (HLUT, n = 10). Maximal aerobic capacity was evaluated by a cardiopulmonary exercise test and forearm blood flow (FBF) by venous occlusion plethysmography. MS was elicited by Stroop color and word test. ET was conducted for 4 mo, 3/wk for 60 min each session. The aerobic exercise intensity corresponded to anaerobic threshold up to 10% below the respiratory compensation point. The strength exercises consisted of two to three sets of chest press, pulley and squat exercises, 12-15 repetitions each exercise at 30-50% of the maximal voluntary contraction. Baseline was similar in HL survivors and HC, except peak oxygen consumption (peak V̇o2, P = 0.013) and FBF (P = 0.006) that were lower in the HL survivors. FBF responses during MS were lower in HL survivors (P < 0.001). ET increased peak V̇o2 (11.59 ± 3.07%, P = 0.002) and FBF at rest (33.74 ± 5.13%, P < 0.001) and during MS (24 ± 5.31%, P = 0.001). Further analysis showed correlation between the changes in peak V̇o2 and the changes in FBF during MS (r = 0.711, P = 0.001). In conclusion, long-term HL survivors have impaired MBF responses during MS. ET restores MBF responses during MS.NEW & NOTEWORTHY Long-term Hodgkin lymphoma (HL) survivors have impaired muscle blood flow responses during mental stress and decreased maximal aerobic capacity. Supervised aerobic exercise training combined with local strength exercises restores muscle blood flow responses during mental stress and maximal aerobic capacity in these survivors. These findings provide evidence of safety and effectiveness of exercise training in HL survivors. Moreover, they highlight the importance of exercise training in the treatment of this set of patients.

Acute hemodynamic responses from low-load resistance exercise with blood flow restriction in young and older individuals: A systematic review and meta-analysis of cross-over trials.

OBJECTIVE: To summarize the existing evidence on the acute response of low-load (LL) resistance exercise (RE) with blood flow restriction (BFR) on hemodynamic parameters. DATA SOURCES: MEDLINE (via PubMed), EMBASE (via Scopus), SPORTDiscus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Science and MedRxiv databases were searched from inception to February 2022. REVIEW METHODS: Cross-over trials investigating the acute effect of LLRE + BFR versus passive (no exercise) and active control methods (LLRE or HLRE) on heart rate (HR), systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure responses. RESULTS: The quality of the studies was assessed using the PEDro scale, risk of bias using the RoB 2.0 tool for cross-over trials and certainty of the evidence using the GRADE method. A total of 15 randomized cross-over studies with 466 participants were eligible for analyses. Our data showed that LLRE + BFR increases all hemodynamic parameters compared to passive control, but not compared to conventional resistance exercise. Subgroup analysis did not demonstrate any differences between LLRE + BFR and low- (LL) or high-load (HL) resistance exercise protocols. Studies including younger volunteers presented higher chronotropic responses (HR) than those with older volunteers. CONCLUSIONS: Despite causing notable hemodynamic responses compared to no exercise, the short-term LL resistance exercise with BFR modulates all hemodynamic parameters HR, SBP, DBP and MBP, similarly to a conventional resistance exercise protocol, whether at low or high-intensity. The chronotropic response is slightly higher in younger healthy individuals despite the similarity regarding pressure parameters.

Relationship between heart rate variability and performance in eccentric training with blood flow restriction.

BACKGROUND: The resistance training with blood flow restriction (BFR) presents results in strength gain and muscle hypertrophy. However, there are no data that evaluate the long-term adaptation of the autonomic nervous system and its influence on the performance, especially with eccentric contractions. OBJECTIVE: To perform a systematic autonomous monitoring during eccentric training with BFR at different loads and to correlate them with possible changes in the performance METHODS: This is a 4-arms, randomized controlled and single blind trial. Sixty men were randomized in four groups: low and high load eccentric exercise (LL and HL); LL and HL with BFR (LL-BFR and HL-BFR). The participants underwent 18 sessions of eccentric exercise for the dominant quadriceps femoris muscle in the isokinetic dynamometer. The performance (strength through isometric, concentric and eccentric peaks torque on the isokinetic dynamometer and Single-leg Hop Test) was evaluated 1 week before, in the fourth week and 1 week after the end of the training programme. Heart rate variability (HRV) through vagal and global indices was evaluated daily for 15 min before each session. RESULTS: There was a significant correlation between performance and HRV for LL and HL-BFR groups, with an increase in parasympathetic indices in the first group and an increase in performance in the second group. CONCLUSION: HRV indices are correlated with performance. However, in the LL group, there was an increase in parasympathetic indices without repercussions on performance while, in the HL-BFR group, there was an increase in performance and no repercussion in the autonomic indices.

Evaluación morfológica del músculo subclavio en una muestra de material de autopsia: inferencias clínicas / Morphological evaluation of the subclavian muscle in a sample of autopsy material: clinical inferences

RESUMEN: El músculo subclavio (MS) guarda estrecha relación con las estructuras neurovasculares (ENV) en el tercio medio de la región clavicular, situación de suma importancia para la realización de procedimientos invasivos de esta región. Pocos estudios han determinado la distancia desde el MS hacia la vena subclavia (VS), arteria subclavia (AS) y plexo braquial (PB). El propósito de este estudio fue valuar la expresión morfológica del MS y su relación con las ENV en una muestra de especímenes cadavéricos frescos. Estudio descriptivo en el que se realizó disección anatómica sobre la región clavicular de 30 especímenes de cadáveres humanos frescos no reclamados del Instituto Nacional de Medicina Legal y Ciencias Forenses, Colombia. Se realizó la caracterización cualitativa y cuantitativa del MS y se determinó la relación del MS con las ENV en la región clavicular. El MS presentó una longitud de 102,4±10,3 mm, con un espesor anteroposterior de 8,8±1,9 mm y superoinferior de 7,0±1,9 mm. El MS se caracterizó así: tipo I en 12 (40 %) especímenes, tipo II en 18 especímenes, tipo IIa: 10 especímenes. No encontramos tipos III y IV. La VS, AS y PB se relacionaron con el MS en el tercio medial y medio de su longitud a una distancia desde el margen superior del MSde 9,4±2,2 mm, 11,3±2,1 mm y 12,0±1,5 mm respectivamente. Los MS se relacionaron con las ENV de la región clavicular en una zona comprendida entre el 36,2±3,6 % y 89,4±4,8 % de su longitud total. Los hallazgos cualitativos y morfométricos de este estudio enriquecen los conceptos anatómicos subclaviculares y son de utilidad para el manejo quirúrgico de fracturas de clavícula.

SUMMARY: The subclavian muscle (MS) is closely related to the neurovascular structures (VNS) in the middle third of the clavicular region, and is critical when performing invasive procedures in this region. Few studies have determined the distance from the MS to the subclavian vein (VS), subclavian artery (AS) and brachial plexus (PB). The purpose of this study was to evaluate the morphological expression of MS and its relationship with VNS in a sample of fresh cadaveric specimens. The study involved the anatomical dissection in the clavicular region of 30 specimens of fresh unclaimed human cadavers from the National Institute of Forensic Medicine and Sciences, Colombia. The qualitative and quantitative characterization of the MS was carried out and the relationship of the MS with the VNS in the clavicular region was determined. The MS presented a length of 102.4 ± 10.3 mm, with an anteroposterior thickness of 8.8 ± 1.9 mm and a superoinferior thickness of 7.0 ± 1.9 mm. The DM was characterized as follows: type I in 12 (40 %) specimens, type II in 18 specimens, type IIa: 10 specimens. We did not find types III and IV. The SV, AS and PB were related to the MS in the medial and middle third of its length at a distance from the upper edge of the MS of 9.4 ± 2.2 mm, 11.3 ± 2.1 mm and 12.0 ± 1,5 mm respectively. The MS were related to the VNS of the clavicular region in an area between 36.2 ± 3.6 % and 89.4 ± 4.8 % of its total length. The qualitative and morphometric findings of this study enrich the subclavicular anatomical concepts and are useful for the surgical management of clavicle fractures.

Peripheral microcirculatory alterations are associated with the severity of acute respiratory distress syndrome in COVID-19 patients admitted to intermediate respiratory and intensive care units.

BACKGROUND: COVID-19 is primarily a respiratory disease; however, there is also evidence that it causes endothelial damage in the microvasculature of several organs. The aim of the present study is to characterize in vivo the microvascular reactivity in peripheral skeletal muscle of severe COVID-19 patients. METHODS: This is a prospective observational study carried out in Spain, Mexico and Brazil. Healthy subjects and severe COVID-19 patients admitted to the intermediate respiratory (IRCU) and intensive care units (ICU) due to hypoxemia were studied. Local tissue/blood oxygen saturation (StO2) and local hemoglobin concentration (THC) were non-invasively measured on the forearm by near-infrared spectroscopy (NIRS). A vascular occlusion test (VOT), a three-minute induced ischemia, was performed in order to obtain dynamic StO2 parameters: deoxygenation rate (DeO2), reoxygenation rate (ReO2), and hyperemic response (HAUC). In COVID-19 patients, the severity of ARDS was evaluated by the ratio between peripheral arterial oxygen saturation (SpO2) and the fraction of inspired oxygen (FiO2) (SF ratio). RESULTS: Healthy controls (32) and COVID-19 patients (73) were studied. Baseline StO2 and THC did not differ between the two groups. Dynamic VOT-derived parameters were significantly impaired in COVID-19 patients showing lower metabolic rate (DeO2) and diminished endothelial reactivity. At enrollment, most COVID-19 patients were receiving invasive mechanical ventilation (MV) (53%) or high-flow nasal cannula support (32%). Patients on MV were also receiving sedative agents (100%) and vasopressors (29%). Baseline StO2 and DeO2 negatively correlated with SF ratio, while ReO2 showed a positive correlation with SF ratio. There were significant differences in baseline StO2 and ReO2 among the different ARDS groups according to SF ratio, but not among different respiratory support therapies. CONCLUSION: Patients with severe COVID-19 show systemic microcirculatory alterations suggestive of endothelial dysfunction, and these alterations are associated with the severity of ARDS. Further evaluation is needed to determine whether these observations have prognostic implications. These results represent interim findings of the ongoing HEMOCOVID-19 trial. Trial registration ClinicalTrials.gov NCT04689477 . Retrospectively registered 30 December 2020.

Effect of resistance training with blood flow restriction on muscle damage markers in adults: A systematic review.

BACKGROUND: The purpose of this review was to systematically analyze the evidence regarding the occurrence of muscle damage (changes in muscle damage markers) after resistance training with blood flow restriction sessions. MATERIALS AND METHODS: This systematic review was conducted in accordance with the PRISMA recommendations. Two researchers independently and blindly searched the following electronic databases: PubMed, Scopus, Web of Science, CINAHL, LILACS and SPORTdicus. Randomized and non-randomized clinical trials which analyzed the effect of resistance training with blood flow restriction on muscle damage markers in humans were included. The risk of bias assessment was performed by two blinded and independent researchers using the RoB2 tool. RESULTS: A total of 21 studies involving 352 healthy participants (men, n = 301; women, n = 51) were eligible for this review. The samples in 66.6% of the studies (n = 14) were composed of untrained individuals. All included studies analyzed muscle damage using indirect markers. Most studies had more than one muscle damage marker and Delayed Onset Muscle Soreness was the measure most frequently used. The results for the occurrence of significant changes in muscle damage markers after low-load resistance training with blood flow restriction sessions were contrasting, and the use of a pre-defined repetition scheme versus muscle failure seems to be the determining point for this divergence, mainly in untrained individuals. CONCLUSIONS: In summary, the use of sets until failure is seen to be determinant for the occurrence of significant changes in muscle damage markers after low-load resistance training with blood flow restriction sessions, especially in individuals not used to resistance exercise. TRIAL REGISTRATION: Register number: PROSPERO number: CRD42020177119.

Role of Matricellular CCN Proteins in Skeletal Muscle: Focus on CCN2/CTGF and Its Regulation by Vasoactive Peptides.

The Cellular Communication Network (CCN) family of matricellular proteins comprises six proteins that share conserved structural features and play numerous biological roles. These proteins can interact with several receptors or soluble proteins, regulating cell signaling pathways in various tissues under physiological and pathological conditions. In the skeletal muscle of mammals, most of the six CCN family members are expressed during embryonic development or in adulthood. Their roles during the adult stage are related to the regulation of muscle mass and regeneration, maintaining vascularization, and the modulation of skeletal muscle fibrosis. This work reviews the CCNs proteins' role in skeletal muscle physiology and disease, focusing on skeletal muscle fibrosis and its regulation by Connective Tissue Growth factor (CCN2/CTGF). Furthermore, we review evidence on the modulation of fibrosis and CCN2/CTGF by the renin-angiotensin system and the kallikrein-kinin system of vasoactive peptides.

Application and side effects of blood flow restriction technique: A cross-sectional questionnaire survey of professionals.

ABSTRACT: The physiological benefits of applying blood flow restriction (BFR) in isolation or in the presence of physical exercise have been widely documented in the scientific literature. Most investigations carried out under controlled laboratory conditions have found the technique to be safe. However, few studies have analyzed the use of the technique in clinical settings.To analyze how the BFR technique has been applied by professionals working in the clinical area and the prevalence of side effects (SEs) resulting from the use of this technique.This is a cross-sectional study. A total of 136 Brazilian professionals who perform some function related to physical rehabilitation, sports science, or physical conditioning participated in this study. Participants answered a self-administered online questionnaire consisting of 21 questions related to the professional profile and methodological aspects and SEs of the BFR technique.Professionals reported applying the BFR technique on individuals from different age groups from youth (≤18 years; 3.5%) to older adults (60-80 years; 30.7%), but mainly on people within the age group of 20 to 29 years (74.6%). A total of 99.1% of the professionals coupled the BFR technique with resistance exercise. Their main goals were muscle hypertrophy and physical rehabilitation. The majority (60.9%) of interviewees reported using BFR in durations of less than 5 minutes and the pressure used was mainly determined through the values of brachial blood pressure and arterial occlusion. Moreover, 92% of professionals declared observing at least 1 SE resulting from the BFR technique. Most professionals observed tingling (71.2%) and delayed onset of muscle soreness (55.8%). Rhabdomyolysis, fainting, and subcutaneous hemorrhaging were reported less frequently (1.9%, 3.8%, and 4.8%, respectively).Our findings indicate that the prescription of blood flow restriction technique results in minimal serious side effects when it is done in a proper clinical environment and follows the proposed recommendations found in relevant scientific literature.

Blood Pressure Response to Muscle Metaboreflex Activation is Impaired in Men Living with HIV.

We investigated the muscle metaboreflex contribution to blood pressure response during dynamic handgrip exercise in men living with HIV (MLHIV) vs. without HIV (Controls). Pressor and heart rate responses were evaluated during metaboreflex activation through post-exercise muscle ischemia (PEMI) method and control exercise session (CER) in 17 MLHIV and 21 Controls. Protocols were performed randomly on the same day, being both sessions composed of 12 min, as follows: a) 3 min at rest, b) 3 min of dynamic handgrip exercise at 30% of maximal voluntary contraction, c) 3 min of recovery post-exercise with vascular occlusion (occlusion only in PEMI), and d) 3 min of recovery post-exercise without vascular occlusion. To assess metaboreflex response, differences between PEMI and CER in recovery post-exercise were calculated for blood pressure and heart rate. Systolic and mean blood pressure (P<0.01) were superior in the last 2 min of recovery with vascular occlusion at PEMI in relation to CER for both groups. No difference was found between groups for blood pressure and heart rate (P>0.05). However, metaboreflex response for systolic blood pressure was lower in MLHIV vs. Controls (4.05±4.63 vs. 7.61±3.99 mmHg; P=0.01). In conclusion, pressor response during metaboreceptor stimulation was attenuated in men living with HIV, which may suggest loss of muscle metaboreflex sensibility.

Low-intensity resistance exercise with blood flow restriction and arterial stiffness in humans: A systematic review.

Low-intensity resistance exercise with blood flow restriction exercise is an emerging type of exercise recognition worldwide. This systematic review evaluated the effects of low-intensity resistance exercise performed with concurrent blood flow restriction (LIRE-BFR) on acute and chronic measures of arterial stiffness in humans. A systematic search in six healthcare science databases and reference lists was conducted. Data selected for primary analysis consisted of post-intervention changes in arterial stiffness markers. This systematic review included randomized and non-randomized controlled trials of LIRE-BFR in humans. 156 articles were initially identified, 15 of which met inclusion criteria. Ten studies were excluded because they did not match predefined arterial stiffness markers. Thus, five articles were included in this review: two acute studies (N = 39 individuals, age = 20-30 years old, 30.8% women and 69.2% men) and three longitudinal studies (N = 51 individuals, age = 24-86-years old, 41.2% women and 58.8% men). Acute LIRE-BFR demonstrated both positive and negative effects on arterial stiffness in healthy young people. In contrast, longitudinal studies reported neutral effects in healthy young and older people. In conclusion, LIRE-BFR applied to the upper and lower limbs may acutely induce increases in central blood pressure and pulse wave velocity in healthy young people, whereas LIRE-BFR for the lower limbs may elicit positive effects related to indirect markers of arterial stiffness. Moreover, longitudinal LIRE-BFR studies showed no changes in arterial stiffness in young and older people. Hence, LIRE-BFR should be prescribed with a degree of caution to avoid non-intended responses in arterial stiffness markers in humans.

The blood flow restriction training effect in knee osteoarthritis people: a systematic review and meta-analysis.

OBJECTIVE: To synthesize evidence on the effects of blood flow restriction (BFR) comparing with high (HLT) and low load (LLT), and on the influence of different forms of application in individuals with knee osteoarthritis. DATA SOURCES: The CENTRAL, PEDro, PubMed and BVS, which include Lilacs, Medline and SciELO, until April 2020. REVIEW METHODS: A systematic review and meta-analysis of randomized trials used the PRISMA guidelines, whose main keywords were: Therapeutic Occlusion, Resistance Training, and Knee Osteoarthritie, blood flow restriction and Kaatsu training. Method quality was evaluated with the PEDro scale. When studies demonstrated homogeneity on outcome measures, the mean differences or standardized mean differences with 95% confidence interval were calculated and pooled in a meta-analysis for pooled synthesis. RESULTS: Five articles were eligible in this review with moderate to low risk bias. Our results, showed no difference between BFR and HLT in knee strength (SMD = 0.00, 95% CI, -0.54 to 0.54, P = 1.00), function (SMD = -0.20, 95% CI, -0.45 to 0.06, P = 0.13), pain and volume. But, when compared BFR and LLT, the descriptive analysis demonstrated significant results in favor BFR to muscle strength (71.4% of measurement) and volume (MD = 1.66, 95% CI, 0.93 to 2.38, P < 0.00001), but not in pain or function. CONCLUSION: BFR can be used as a strategy in the rehabilitation of osteoarthritis due to gains in strength and volume with low mechanical stress. However, its application must be safe and individualized, since they can attenuate the stimuli offered by BFR.

Effect of intramuscular baculovirus encoding mutant hypoxia-inducible factor 1-alpha on neovasculogenesis and ischemic muscle protection in rabbits with peripheral arterial disease.

BACKGROUND AIMS: Peripheral arterial disease (PAD) is a progressive, disabling ailment for which no effective treatment exists. Gene therapy-mediated neovascularization has emerged as a potentially useful strategy. We tested the angiogenic and arteriogenic efficacy and safety of a baculovirus (BV) encoding mutant, oxygen-resistant hypoxia-inducible factor 1-alpha (mHIF-1α), in rabbits with PAD. METHODS: After assessing the transfection efficiency of the BV.mHIF-1α vector and its tubulogenesis potential in vitro, we randomized rabbits with experimental PAD to receive 1 × 109 copies of BV.mHIF-1α or BV.null (n = 6 per group) 7 days after surgery. Two weeks post-treatment, collateralization (digital angiography) and capillary and arteriolar densities (immunohistochemistry) were measured in the posterior limbs. Ischemic damage was evaluated in adductor and gastrocnemius muscle samples. Tracking of viral DNA in injected zones and remote tissues at different time points was performed in additional rabbits using a BV encoding GFP. RESULTS: Angiographically visible collaterals were more numerous in BV.mHIF-1α-treated rabbits (8.12 ± 0.42 vs 6.13 ± 1.15 collaterals/cm2, P < 0.05). The same occurred with arteriolar (27.9 ± 7.0 vs 15.3 ± 4.0 arterioles/mm2) and capillary (341.8 ± 109.9 vs 208.8 ± 87.7 capillaries/mm2, P < 0.05) densities. BV.mHIF-1α-treated rabbits displayed less ischemic muscle damage than BV.null-treated animals. Viral DNA and GFP mRNA were detectable only at 3 and 7 days after injection in hind limbs. Neither the virus nor GFP mRNA was detected in remote tissues. CONCLUSIONS: In rabbits with PAD, BV.mHIF-1α induced neovascularization and reduced ischemic damage, exhibiting a good safety profile at 14 days post-treatment. Complementary studies to evaluate its potential usefulness in the clinic are needed.

Dietary nitrate improves skeletal muscle microvascular oxygenation in HIV-infected patients receiving highly active antiretroviral therapy: a randomised, double-blind, cross-over, placebo-controlled study.

HIV-1 proteins and highly active antiretroviral therapy (HAART) have been associated with microvascular endothelial dysfunction. Although nitrate-rich beetroot juice (NR-BJ) consumption has been shown to improve endothelial function in clinical population, its effects in HIV-infected patients has not been addressed. We investigated the effect of a single dose of NR-BJ on muscle oxygen saturation parameters in response to a handgrip exercise in HIV-infected patients. Fifteen HIV-infected patients received NR-BJ or nitrate-depleted beetroot juice (ND-BJ) in a double-blind cross-over design. Near-IR spectroscopy was utilised to assess muscle oxygen saturation parameters during rhythmic handgrip exercise after NR-BJ or ND-BJ supplementation. A significant faster muscle oxygen desaturation rate during exercise (-7·97 (sd 5·00) v. -5·45 (3·94) %/s, P = 0·005) and muscle oxygen resaturation rate during exercise recovery (0·43 (0·24) v. 0·28 (0·24) %/s, P = 0·030) after NR-BJ ingestion was found. However, no significant difference in exercise time until fatigue was observed. Salivary nitrite and urinary nitrate concentration were analysed after NR-BJ or ND-BJ. A significant increase in salivary nitrite and urinary nitrate in NR-BJ was observed compared with ND-BJ (P < 0·05). Our findings suggest that NR-BJ consumption may acutely improve muscle oxygen saturation during exercise and exercise recovery in HIV-infected patients undergoing HAART and who are expected to present microvascular damage. Thus, future studies investigating the chronic effects of NR-BJ are warranted to delineate a better nutritional strategy based on nitrate-rich foods.

Supervised exercise protocol for lower limbs in subjects with chronic venous disease: an evaluator-blinded, randomized clinical trial.

BACKGROUND: Chronic venous insufficiency (CVI) causes pathophysiological changes in the lower-limb muscles, particularly the calf muscles, and limits ankle range of motion (ROM). These changes reduce functional activities and decrease quality of life (QOL). Although several studies have shown the benefits of exercise (strengthening the calf muscles to improve calf-muscle pumping and QOL) in patients with CVI, few studies are randomized controlled trials. This has led to a weak indication of exercise for the treatment of patients with CVI. The aim of this study is to analyze the effects of a supervised exercise program to improve calf-muscle endurance as well as QOL in patients with CVI. METHODS/DESIGN: This is an evaluator-blind, randomized clinical trial with an 8-week duration and a follow-up evaluation at week 16. A pilot study with subjects with a CVI diagnosis will be performed to calculate sample size. The participants will be randomly allocated (1:1) into a treatment or a control group (usual care/no intervention). The treatment intervention consists of a bi-weekly supervised exercise program of the lower limbs that will include aerobic training, strengthening and cardiovascular exercises. The participants from both groups will participate in a health education lecture. Primary outcomes are changes in calf-muscle endurance and QOL score. Secondary outcomes are changes in exercise capacity, ankle ROM, electrical muscle activity and cardiac output. The first statistical comparison will be performed after 8 weeks' intervention. DISCUSSION: Patients with CVI may have an impaired calf-muscle pump and decreased exercise capacity. A randomized controlled trial evaluating a supervised exercise program should provide much needed information on the management of CVI to promote health and independence. TRIAL REGISTRATION: This study was registered on the Brazilian Clinical Trials Database (REBEC) (RBR-57xtk7). The results will be disseminated at scientific events, presentations, and publications in peer-reviewed journals.

Near-infrared spectroscopy-derived muscle oxygen saturation during exercise recovery and flow-mediated dilation are impaired in HIV-infected patients.

Highly active antiretroviral therapy has been associated with the presence of endothelial dysfunction in HIV-infected patients, which may impair oxygen delivery to muscles during exercise and exercise recovery. Near-infrared spectroscopy (NIRS) has been used to assess muscle oxygen saturation (SmO2) kinetics during exercise in different clinical populations in order to evaluate the balance between oxygen delivery and utilization by muscles. However, studies assessing SmO2 in HIV-infected patients have not been conducted. Therefore, the aim of the study was to evaluate NIRS-derived SmO2 during rhythmic handgrip exercise and flow-mediated dilation (FMD) in HIV-infected patients (HIV) compared to non-HIV-infected controls (N-HIV). Eighteen HIV and 17 N-HIV individuals underwent FMD assessment by ultrasound. The subjects then performed one set of rhythmic handgrip exercise until fatigue at 30% maximal isometric voluntary contraction. SmO2 was measured during entire exercise and 2-min exercise 3recovery. Muscle oxygen resaturation rate (upslope of the SmO2 over 10 s of recovery) was calculated. A significant lower FMD (3.5 ± 1.7 vs 5.9 ± 1.5%, P < 0.001) and slower oxygen resaturation rate (0.78 ± 0.4 vs 1.14 ± 0.4%·s-1, P = 0.020) in HIV as compared to N-HIV group were observed. In conclusion, our findings demonstrated that HIV-infected patients had reduced FMD and impaired muscle oxygenation during exercise recovery compared to non-HIV individuals.

Near-infrared spectroscopy-derived total haemoglobin as an indicator of changes in muscle blood flow during exercise-induced hyperaemia.

Blood flow changes in response to exercise have been attributed, among other factors, to the effect of vasodilators factors on the microvasculature, suggesting a close relationship between small blood vessels and conducting arteries. The main purpose of this study was to determine the relationship between the changes in near infrared spectroscopy (NIRS)-derived total haemoglobin ([tHb]) and muscle oxygen saturation (SmO2) signals and femoral artery blood flow in response to resistance exercise at fast- and slow-velocity muscle contraction. The study randomised crossover design included twelve participants. NIRS and blood flow measurements were continuously monitored before, during, and 5 min after the exercise protocol. There was a significant correlation between [tHb] reperfusion slope ([tHb]slope) and peak blood flow (BFpeak) after slow- and fast-velocity muscle contraction (r = 0.83, p = 0.0008 and r = 0.72, p = 0.0080, respectively). No significant correlation existed between the SmO2 reperfusion slope (SmO2_slope) and BFpeak after both slow- and fast-velocity muscle contraction exercise (r = -0.46, p = 0.1253 and r = 0.33, p = 0.2841, respectively). This study demonstrated a strong relationship between the NIRS-derived [tHb] and Doppler ultrasound BF during the recovery period of dynamic resistance exercise at both slow- and fast-velocity contraction.

MicroRNA-126 upregulation, induced by training, plays a role in controlling microcirculation in dexamethasone treated rats.

Microcirculation maintenance is associated with microRNAs. Nevertheless, the role of microRNAs induced by training in preventing dexamethasone (DEX)-induced microvascular rarefaction remains unknown. The study aim was to investigate if training-induced microRNAs are able to improve microcirculation proteins and prevent DEX-induced microvascular rarefaction. Rats underwent training for 8 weeks and then were treated with DEX (50 µg/kg per day, s.c.) for 14 days. Arterial pressure was measured and tibialis anterior (TA) muscle was collected for analyses. DEX induced hypertension concomitantly with capillary density loss (CD, -23.9%) and decrease of VEGF (-43.0%), p-AKT/AKT (-39.6%) and Bcl-2 (-23.0%) and an increase in caspase-3-cleaved protein level (+34.0%) in TA muscle. Training upregulated microRNA-126 expression (+13.1%), prevented VEGF (+61.4%), p-AKT/AKT (+37.7%), Bcl-2 (+7.7%) decrease and caspase-3-cleaved (-23.1%) increase associated with CD (+54.7%) reduction and hypertension prevention. MiRNA-126 upregulation, induced by training, plays a role in controlling microcirculation, which may be a potential target against DEX-induced microvascular rarefaction.