The effect of microencapsulated watermelon rind (Citrullus lanatus) and beetroot (Beta vulgaris L.) ingestion on ischemia/reperfusion-induced endothelial dysfunction: a randomised clinical trial

Endothelial dysfunction is commonly associated with a cardiovascular event, such as myocardial infarction. Myocardial infarction is marked by an ischemia/reperfusion (IR) phenomenon associated with endothelial dysfunction, contributing even more to future cardiovascular events. Although the supplementation with L-citrulline and nitrate from watermelon and beetroot have been used to improve vascular function, the effect of microencapsulated watermelon rind (WR) or its co-ingestion with beetroot (WR + B) on endothelial IR injury has not been addressed. Therefore, this study aimed to investigate the effect of a single dose of WR and WR + B on IR-induced macro-and microvascular dysfunction. In a randomized, crossover, placebo-controlled study, 12 volunteers underwent macro (flow-mediated dilation) and microvascular (muscle oxygen saturation) assessment and blood collection (to measure L-citrulline, L-arginine, nitrate and nitrite) before and after 20 min of blood occlusion in WR, WR + B and placebo conditions. Prolonged ischemia induced endothelial dysfunction in the macro but not in the microvasculature. The WR and WR + B supplementation significantly restored FMD after IR injury compared to the placebo (p < 0.05). However, there was no significant difference between WR and WR + B in the macrovascular function (p > 0.05). Plasma L-citrulline, L-arginine, nitrate, and nitrite significantly increased (p > 0.05) after WR and WR + B supplementation compared to the placebo. A single dose of WR and WR + B effectively minimizes IR-induced macrovascular endothelial dysfunction in healthy individuals. Beetroot co-ingestion with watermelon did not provide an additional effect of endothelial dysfunction induced by IR (NCT04781595, March 4, 2021).

A single dose of microencapsulated cocoa supplementation attenuated eccentric exercise-induced endothelial dysfunction

In the present study, it was evaluated whether microencapsulated cocoa supplementation could attenuate endothelial dysfunction caused by eccentric exercise in healthy subjects. Thirteen volunteers were enrolled in this double-blind, placebo-controlled, crossover study. Flow-mediated dilatation (FMD), blood flow and muscle O₂ saturation (StO₂) were evaluated by ultrasound and near-infrared spectroscopy (NIRS), respectively, before and after microencapsulated cocoa supplementation. The eccentric exercise was performed after microencapsulated cocoa supplementation to generate vascular dysfunction. Eccentric exercise significantly reduced FMD in the PLA condition, but cocoa attenuated this exercise effect. No significant effect was observed on muscle StO₂ and blood flow after eccentric exercise and nutritional supplementation. In conclusion, the present study showed that a single dose of microencapsulated cocoa ingestion attenuated FMD-induced eccentric exercise. These findings suggest that a single dose of microencapsulated cocoa may be an alternative nutritional strategy to attenuate vascular dysfunction induced by eccentric exercise in healthy individuals.

Effect of microencapsulated watermelon (Citrullus Lanatus) rind on flow-mediated dilation and tissue oxygen saturation of young adults

BACKGROUND/OBJECTIVES

Watermelon rind (usually discarded by consumers) presents a high L-citrulline content. Given that Lcitrulline is involved in nitric oxide (NO) synthesis, a crucial molecule that regulates vascular function, this study aimed to evaluate the effect of microencapsulated watermelon rind (MWR) on endothelial function and tissue oxygen saturation (StO2) assessed by flow-mediated dilation (FMD) and near-infrared spectroscopy, respectively. Plasma L-arginine and L-citrulline were also evaluated.

SUBJECT/METHODS

Eleven participants ingested 30 g of MWR (containing 4 g of L-citrulline) and a placebo. Before and 30, 60, 90, and 120 min after ingestion, StO2 parameters were assessed, whereas FMD and plasma amino acids were analyzed 60 and 120 min after ingestion.

RESULTS

The FMD improved 60 min after MWR without changes in StO2 parameters. Absolute plasma L-citrulline and relative change from baseline in plasma L-arginine increased 60 min after MWR ingestion.

CONCLUSION

A single dose of microencapsulated watermelon rind containing 4 g of L-citrulline seems adequate to improve FMD response, but not StO2 parameters in healthy adults. (NCT04781595).

The effect of dietary nitrate on macro- and microvascular function: A systematic review

Previous studies have investigated the impact of dietary nitrate on vascular function due to the association between dietary nitrate ingestion and improvement in nitric oxide (NO) bioavailability. Considering that NO can present different effects through vascular beds (macro- vs. microvasculature) due to the specific characteristic (function and morphology) that each vessel exhibits, it is crucial to investigate the effect of dietary nitrate ingestion on the macro- and microvascular function to understand the effect of nitrate on vascular function. For this reason, this review aimed to evaluate the impact of dietary nitrate on macro- and microvascular function in humans. A total of 29 studies were included in the systematic review, of which 19 studies evaluated the effect of nitrate supplementation on macrovascular function, eight studies evaluated the effect on microvascular function, and two studies evaluated the impact on both macro- and microvascular function. The literature suggests that dietary nitrate ingestion seems to improve the vascular function in macrovasculature, whereas microvascular function appears to be modest. Future studies investigating the effect of nitrate ingestion on vascular function should focus on measuring macro- and microvascular function whenever possible so that the impact of nitrate-rich foods on vascular segments could be better understood.

Improved microvascular reactivity after aged garlic extract intake is not mediated by hydrogen sulfide in older adults at risk for cardiovascular disease: a randomized clinical trial

PURPOSE

This study aimed to investigate the effects of AGE on microvascular reactivity, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in older individuals at high risk for cardiovascular disease (CVD). Urinary thiosulfate was also investigated as an indirect marker of endogenous hydrogen sulfide (H₂S) synthesis. The study was conducted in a randomized, double-blind, crossover, and placebo-controlled way.

METHODS

Twenty-eight participants (14 male), 67 ± 6 years old with CVD risk factors, ingested 2.4 g of AGE or placebo (PLA). Near-infrared spectroscopy evaluated tissue oxygen saturation (StO₂) during a vascular occlusion test (30 s baseline, 5 min occlusion, and 2 min reperfusion). The upslope of StO₂ signal after cuff release was calculated to measure microvascular reactivity. Urinary thiosulfate levels were measured using a high-performance liquid chromatography system.

RESULTS

The upslope of StO₂ was significantly faster after AGE (1.01 ± 0.37% s^-1) intake compared to PLA (0.83 ± 0.35% s^-1; P < 0.001; d = 0.50). Relative changes in Δ% SBP from pre- to post-AGE intake (- 5.17 ± 5.77%) was significantly different compared to Δ% PLA (0.32 ± 5.99%; P = 0.001; d = 0.93). No significant changes in urinary thiosulfate concentrations were observed between interventions. Moreover, no significant gender effect in any parameter assessed was found.

CONCLUSION

This study demonstrated that a single dose of AGE improved microvascular reactivity in older adults at risk of CVD despite such an effect was not linked with urinary thiosulfate levels. This trial was registered at clinicaltrials.gov as NCT04008693 (May 19, 2020).

Impact of microencapsulated watermelon (Citrullus lanatus) and beetroot (Beta vulgaris L) on storage stability of l-citrulline and dietary nitrate

The aim the current study was to developed a watermelon rind powder (WRP), watermelon pulp powder (WPP), and beetroot powder (BP), in order to compare the stability of L-citrulline and nitrate with that of watermelon rind juice (WRJ), watermelon pulp juice (WPJ), and beetroot juice (BJ), respectively. The stability was evaluated during 32 days at 25, 4 and - 20 ºC. L-arginine and L-ornithine content were also evaluated. At day 0, a significantly higher L-citrulline and L-ornithine content in WRP was observed when compared to WPP. However, a significantly lower L-arginine content in WRP was observed when compared to WPP. L-citrulline content in WRP and WRJ was stable over 32 days in all temperatures evaluated, whereas it reduced in WPP in 32 days at 25 ºC and it is reduced in in WPJ in day 16 and day 32 at 25 °C. L-arginine content in WRP and WPP was stable over 32 days in all temperatures evaluated. A reduction was observed in WRJ at day 2, 4 and 32 at 25 °C and in WPJ at day 2, 4, 8, 16 and 32 days at 25 °C. L-ornithine content in WRP and WPP was stable over 32 days in all temperatures evaluated. An increase was observed in WRJ at day 2, 4 and 32 at 25 °C and in WPJ in day 2, 4, 8, 16 and 32 at 25 °C. Nitrate content in BP was stable over 32 days in all temperatures evaluated, while nitrate content in beetroot juice was reduced in day 2 at 25 °C and day 8 at 4 °C. In conclusion, L-citrulline of the microencapsulated watermelon rind and nitrate of the microencapsulated beetroot were stable throughout storage.

Turmeric root extract supplementation improves pre-frontal cortex oxygenation and blood volume in older males and females: a randomised cross-over, placebo-controlled study

Ageing is associated with endothelial dysfunction and reduced cerebral blood flow and oxygenation. The present study aimed to investigate whether turmeric supplementation could improve cerebral oxygenation and blood volume during brain activation via dynamic handgrip exercise in older males and females. Twelve older males and females were studied using a double-blind, placebo-controlled, cross-over design. Participants ingested turmeric root extract or placebo. Heart rate and blood pressure were measured before and 2 hours after supplementation. Afterward, the exercise protocol was started, and cerebral oxygenation and blood volume were evaluated. During exercise, changes in cerebral oxygenation were higher after turmeric extract supplementation, as was blood volume compared to placebo. Changes in heart rate, systolic blood pressure, and diastolic blood pressure were not significant. The current findings indicate the potential for curcumin as an intervention for improving cerebral oxygenation and blood volume changes in older males and females. Clinical trial registry: NCT04119752.

Suitability of the muscle O2 resaturation parameters most used for assessing reactive hyperemia: a near-infrared spectroscopy study

Background

There is a spectrum of possibilities for analyzing muscle O₂ resaturation parameters for measurement of reactive hyperemia in microvasculature. However, there is no consensus with respect to the responsiveness of these O₂ resaturation parameters for assessing reactive hyperemia.

Objectives

This study investigates the responsiveness of the most utilized muscle O₂ resaturation parameters to assess reactive hyperemia in the microvasculature of a clinical group known to exhibit impairments of tissue O₂ saturation (StO₂).

Methods

Twenty-three healthy young adults, twenty-nine healthy older adults, and thirty-five older adults at risk of cardiovascular disease (CVD) were recruited. Near-infrared spectroscopy (NIRS) was used to assess StO₂ after a 5-min arterial occlusion challenge and the following parameters were analyzed: StO_{2slope_10s}, StO_{2slope_30s}, and StO_{2slope_until_baseline} (upslope of StO₂ over 10s and 30s and until StO₂ reaches the baseline value); time to StO_2baseline and time to StO_2max (time taken for StO₂ to reach baseline and peak values, respectively); ∆StO_2reperfusion (the difference between minimum and maximum StO₂ values); total area under the curve (StO_2AUCt); and AUC above the baseline value (StO_{2AUC_above_base}).

Results

Only StO_{2slope_10s} was significantly slower in older adults at risk for CVD compared to healthy young individuals (p < 0.001) and to healthy older adults (p < 0.001). Conversely, time to StO_2max was significantly longer in healthy young individuals than in older adult at CVD risk.

Conclusions

Our findings suggest that StO_{2slope_10s} may be a measure of reactive hyperemia, which provides clinical insight into microvascular function assessment.

Effect of dietary nitrate ingestion on muscular performance: a systematic review and meta-analysis of randomized controlled trials

Dietary nitrate consumption from foods such as beetroot has been associated with many physiological benefits including improvements in vascular health and exercise performance. More recently, attention has been given to the use of dietary nitrate as a nutritional strategy to optimize muscular performance during resistance exercise. Our purpose was to perform a systematic review and meta-analysis of the research literature assessing the effect of dietary nitrate ingestion on muscular strength and muscular endurance. A structured search was carried out in accordance with PRISMA guidelines and from the total included studies (n = 34 studies), 12 studies had data for both measurement of strength and muscular endurance outcomes, 14 studies had data only for muscular strength outcome, and 8 studies had data only for muscular endurance outcome. Standardized mean difference (SMD) was calculated and meta-analyses were performed by using a random-effects model. Dietary nitrate ingestion was found to result in a trivial but significant effect on muscular strength (overall SMD = 0.08, P = 0.0240). Regarding muscular endurance dietary nitrate was found to promote a small but significant effect (overall SMD = 0.31, P < 0.0001). Dosage, frequency of ingestion, training level, muscle group, or type of contraction did not affect the findings, except for a greater improvement in muscle endurance during isometric and isotonic when compared to isokinetic contractions. Dietary nitrate seems to have a positive effect on muscular strength and muscular endurance, which is mostly unaffected by dosage, frequency of ingestion, training level, muscle group, or type of contraction. However, given the trivial to small effect, further experimental research on this topic is warranted.

Covid-19 Quarantine: Impact of Lifestyle Behaviors Changes on Endothelial Function and Possible Protective Effect of Beetroot Juice

The current recommendation for reducing person-to-person Coronavirus 2019 (COVID-19) transmission is social distancing, including remote work and school, and home confinement. However, confinement may cause negative feelings, such as frustration, anger, boredom, and stress, in quarantined people. Furthermore, unhealthy diet and physical inactivity behaviors are commonly linked to home confinement, leading to weight gain, metabolic disorders, smoking, and exacerbated alcohol consumption. As a result, these unhealthy behaviors are typically linked to vascular endothelium damage (endothelial dysfunction), which is a first step for the development of cardiovascular disease (CVD). Given that CVD is the main cause of morbidity and mortality worldwide, attenuating the progression of endothelial dysfunction is very important for the control of CVD. Consuming vegetable rich in nitrate, such as beetroots, may be an effective way to prevent endothelial dysfunction. Several emerging studies have recommended beetroot juice in order to improve endothelial function in hypertensive, hypercholesterolemic individuals, as well as in those with CVD risk factors. Therefore, nitrate-rich vegetable consumption, such as beetroot, should be encouraged to be included in the diet during confinement from COVID-19 outbreaks in order to alleviate the potential negative effect of home confinement on cardiovascular health.

Flow-Mediated Dilation in Healthy Young Individuals Is Impaired after a Single Resistance Exercise Session

The current pool of data investigating the effects of a single resistance exercise session on endothelial function is divergent and inconclusive. Therefore, the purpose of the present study was to evaluate the effect of a single resistance exercise session on flow-mediated dilation (FMD) in trained individuals. Eleven healthy, young, recreationally resistance-trained individuals participated in the study. After determining the resistance exercise workload, the participants performed three sets of 10–12 repetition of leg press and leg extension exercises. By using ultrasound equipment, brachial artery FMD was assessed before (PRE) and 30 min after (POST) the resistance exercise protocol or resting (control) to evaluate endothelial function. A significant reduction in FMD response (PRE: 5.73% ± 1.21% vs. POST: 4.03% ± 1.94%, p < 0.01) after resistance exercise was observed, accompanied by a large effect size (d = 1.05). No significant difference was observed in FMD in the control condition (PRE: 5.82% ± 1.19% vs. POST: 5.66% ± 1.24%, p = 0.704). Additionally, no significant difference in baseline brachial artery diameter between resistance exercise (PRE: 3.30 ± 0.32 vs. POST: 3.40 ± 0.34 mm, p = 0.494) and resting (PRE: 3.64 ± 0.41 vs. POST: 3.67 ± 0.62 mm, p = 0.825) was observed. Our findings showed that a single resistance exercise session induced a reduction in FMD in resistance-trained 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 (BF_peak) 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 (SmO_{2_slope}) and BF_peak 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.

Effects of fish protein hydrolysate ingestion on postexercise aminoacidemia compared with whey protein hydrolysate in young individuals

The aminoacidemia resulting from food protein digestion in response to exercise plays an underlying role in the rate of muscle protein synthesis. Whey protein hydrolysate (WPH) has been demonstrated to cause more pronounced postexercise aminoacidemia compared with casein and soy. Although fish protein has been demonstrated to be a great source of amino acids, there is no data available providing information about the postexercise aminoacidemia after fish protein hydrolysate (FPH) intake. The present study investigated the characteristic patterns of postexercise aminoacidemia after WPH and FPH intake in nine physically active subjects (six males and three females). In a crossover, double-blind, and randomized design, all participants received oral doses of either 0.25 g/kg of FPH or WPH or placebo (PLA) immediately after a resistance exercise bout. Blood samples were taken before and at 30, 60, 90, 120 and 180 min after supplementation. There was a significant increase in plasma total amino acids (TAA), essential amino acids (EAA), branched-chain amino acids (BCAA), and leucine concentrations at 30 and 60 min after FPH supplementation, and at 30, 60, 90, and 120 min after WPH as compared to PLA. No significant differences were observed in plasma TAA, EAA, BCAA, and leucine concentrations between FPH and WPH at any time point, and there were no significant difference observed in the area under the curve for TAA, EAA, BCAA, and leucine between FPH and WPH. In conclusion, both FPH and WPH showed a rapid and pronounced postexercise aminoacidemia. FPH presented itself to be an alternative food source of rapidly digested proteins to be used after resistance exercise. PRACTICAL APPLICATION: Fish protein hydrolysate (FPH) demonstrated a rapid and pronounced postexercise aminoacidemia. Whey protein hydrolysate showed similar effects. FPH is presented as an alternative food source of rapidly digested proteins to be consumed by the population, especially physically active individuals.

Is flow-mediated dilatation associated with near-infrared spectroscopy-derived magnitude of muscle O2 desaturation in healthy young and individuals at risk for cardiovascular disease?

Vascular occlusion test (VOT)-induced reactive hyperemia in brachial artery is crucial to flow-mediated dilation (FMD). Emerging studies have suggested that reactive hyperemia depends on the magnitude of the O₂ desaturation (ischemia) in downstream microvessels. Although near-infrared spectroscopy-derived tissue O₂ saturation index (TSI) has been used to assess the magnitude of ischemia, the association between FMD and the magnitude of O₂ desaturation has not been addressed. Therefore, the aim of the present study was to evaluate whether FMD correlates with the magnitude of muscle O₂ desaturation in healthy young individuals and older adults at risk for cardiovascular disease (CVD). Twenty healthy young individuals and 20 others at risk for CVD participated in the study. The magnitude of ischemic stimulus was determined by calculating the area under curve of TSI signal over 5 min of cuff occlusion period. Oxygen resaturation rate was calculated as the upslope of the TSI signal over 10 s following cuff deflation. There was no significant correlation between FMD and the magnitude of ischemic stimulus in both groups assessed (young: R = 0.327; P = 0.159 and older: R = -0.184; P = 0.436). However, a significant correlation between the magnitude of O₂ desaturation and O₂ resaturation rate in young (R = 0.555; P = 0.011) and older individuals at risk for CVD (R = 0.539; P = 0.014). In conclusion, FMD response did not correlate with the magnitude of muscle O₂ desaturation, although it seems to be partially associated with O₂ resaturation rate.

The effects of the analysis strategy on the correlation between the NIRS reperfusion measures and the FMD response

This study aimed to investigate the correlation between near-infrared spectroscopy (NIRS)-derived measures of microvascular responses using a range of different analysis and flow-mediated dilation (FMD). Additionally, we aimed to investigate whether assessing NIRS and FMD simultaneously or non-simultaneously would affect this association. Thirty-five healthy young individuals (26 ± 13 years old) participated in the study. Twenty were submitted to a simultaneous NIRS/FMD test (NIRS probe placed below the cuff during FMD test) and fifteen to a non-simultaneous FMD and NIRS intervention (NIRS test performed 20 min after FMD). NIRS-derived oxygen saturation signal (StO₂) during reperfusion was analyzed as follow: upslope of a 10 s (slope 10 s) and 30 s (slope 30 s) reperfusion window immediately following cuff deflation, time for the StO₂ to reach the pre-occlusion ₍baseline) values after cuff release (time to baseline) and to reach the peak after cuff release (time to max), difference between the minimum and maximum StO₂ value reached after cuff deflation (Magnitude) and; the total area under the reperfusion curve above the baseline value until the end of the 2 min post cuff release (AUC 2 min). There was a significant positive correlation between slope 10 s and FMD in the simultaneous (r = 0.60; p < 0.05) and non-simultaneous (r = 0.62; p < 0.05) assessments. There was no significant correlation between NIRS-derived slope 30 s, time to baseline, time to max, magnitude, and AUC 2 min and the FMD in both methods. The association between NIRS and FMD is analysis strategy dependent, regardless if assessed simultaneously or non-simultaneously.

The effects of aging and cardiovascular risk factors on microvascular function assessed by near-infrared spectroscopy

This study aimed to evaluate whether NIRS-derived reperfusion rate would detect potential differences in the forearm microvascular responsiveness between young healthy adults, and older adults free from or with cardiovascular disease (CVD) risk factors. Fifteen healthy young (age: 24.8 ± 4.0 years), seventeen older adults free of CVD risk factors (age: 67.0 ± 6.8 years), and twenty-three older adults with CVD risk factors (age: 67.9 ± 8.0 years) participated this study. Individuals underwent a blood draw and vascular occlusion test (30 s of baseline, 5 min of occlusion, and 2 min of reperfusion) and microvascular responsiveness was evaluated by using NIRS-derived tissue oxygen saturation indexes during reperfusion. A significant slower reperfusion rate and lower reperfusion magnitude was observed in older adults with CVD risk factors compared to healthy young and older adults. Although no statistical differences were found between healthy young and older individuals, there was a small (d = 0.4) effect size for reperfusion rate and moderate (d = 0.7) effects size for reperfusion magnitude when comparing these groups. In conclusion, this study demonstrated that even though the effects of aging per se on microvascular function should not be completely neglected, the CVD risk factors seem to be determinant on microvascular responsiveness impairment associated with aging.

Effects of fish protein hydrolysate ingestion on endothelial function compared to whey protein hydrolysate in humans

Fish protein-derived bioactive peptides may improve endothelial dysfunction through an antihypertensive and antioxidant effect. However, few studies have evaluated the bioactive peptides effect on vascular function. Therefore, this study investigates the effect of a single dose of fish protein hydrolysate (FPH) or whey protein hydrolysates (WPH) on endothelium-dependent dilation in nine healthy adults. The subjects ingested a single dose (20 g) of FPH, WHP or placebo (PLA). The endothelium-dependent dilation was evaluated by flow-mediated dilatation before and at 30, 60 and 120 min after supplementation. Total antioxidant capacity (TAC) of the FPH and WPH supplements was evaluated by using the Trolox equivalent antioxidant capacity assay. There was a significant increase of endothelium-dependent dilation at 30 min after WPH but not after FPH as compared to PLA. There was a significant great TAC in FPH than WPH supplement. A single dose of FPH was not able to improve endothelium-dependent dilation compared to WPH.

The association between near-infrared spectroscopy assessment of microvascular reactivity and flow-mediated dilation is disrupted in individuals at high risk for cardiovascular disease

OBJECTIVE

This study aimed to evaluate the correlation between the NIRS-derived reperfusion slope and %FMD in the arm of healthy and at high risk for CVD individuals.

METHODS

Twelve healthy (24 ± 4 years) and twelve at high risk for cardiovascular disease (65 ± 11 years) individuals participated in the study. The individuals were submitted to a conduit artery FMD followed by a NIRS-VOT microvascular function test in the arm. Microvascular responsiveness was calculated as the forearm reperfusion slope, and macrovascular function was assessed as the percent of change in FMD (%FMD) of the brachial artery.

RESULTS

There was a significant correlation between reperfusion slope and %FMD (R = 0.61, P < 0.05) in the healthy group; however, no significant correlation between FMD and reperfusion slope (R = -0.21, P > 0.05) was found in individuals at high risk for CVD.

CONCLUSION

The correlation between NIRS-derived reperfusion slope and %FMD was disrupted in the arm of individuals at high risk for cardiovascular disease compared to healthy individuals. The findings of the present study reinforce the importance of examining vascular function at microvasculature and conduit artery level, especially in populations with risk factors for CVD.

Rare variation of the right internal jugular vein: a case study

This study reports on a rare variation of the right internal jugular vein (IJV) identified during routine anatomic dissection of a male cadaver. The right IJV had a tributary located parallel and medially to the IJV itself. This branch of the IJV emerged between the transverse processes of the 3rd and 4th cervical vertebrae and drained into the junction between the right internal jugular and brachiocephalic veins. The present study described a rare branch of the right IJV, which is important knowledge for surgeons, in order to prevent accidental injury and bleeding during surgical procedures.

A DIVULGAÇÃO DE VÍDEOS DE ANATOMIA DO SISTEMA NERVOSO CENTRAL NO YOUTUBE

O estudo visa avaliar os métodos de exposição de conteúdos de neuroanatomia utilizados nos vídeos compartilhados no YouTube, o impacto destes vídeos e a aceitação dos usuários. Trata-se de uma pesquisa quantitativa, com abordagem descritiva e analítica observacional, envolvendo a análise de vídeos de neuroanatomia divulgados em português no site do YouTube. A pesquisa foi realizada no Youtube utilizando as palavras-chave “telencéfalo”, “diencéfalo” e “tronco encefálico”. Os vídeos foram categorizados de acordo com o método de exposição do conteúdo de neuroanatomia como equipamentos multimídia (EM), peças plásticas (PPT), peças plastinadas (PPN), e peças cadavéricas formolizadas (PCF) para avaliação do número de visualizações e aceitação dos usuários (número de likes e dislikes). Foi observado que as PPT foram mais utilizadas nos vídeos de neuroanatomia. Porém, os vídeos que utilizaram EM tiveram mais visualizações diárias e maior aceitação pelos usuários do Youtube. Os resultados do presente estudo sugerem que os vídeos de neuroanatomia utilizando EM podem contribuir de forma complementar para o ensino-aprendizado destes conteúdos

Beetroot-based gel supplementation improves handgrip strength and forearm muscle O2 saturation but not exercise tolerance and blood volume in jiu-jitsu athletes

The ergogenic effect of beetroot on the exercise performance of trained cyclists, runners, kayakers, and swimmers has been demonstrated. However, whether or not beetroot supplementation presents a beneficial effect on the exercise performance of jiu-jitsu athletes remains inconclusive. Therefore, the present study assessed the effect of beetroot-based gel (BG) supplementation on maximal voluntary contraction (MVC), exercise time until fatigue (ETF), muscle O₂ saturation (SmO₂), blood volume (tHb), and plasma nitrate and lactate in response to handgrip isotonic exercise (HIE) in jiu-jitsu athletes. In a randomized, crossover, double-blind design, 12 jiu-jitsu athletes performed 3 sets of HIE at 40% of the MVC until fatigue after 8 days (the eighth dose was offered 120 min previous exercise) of BG supplementation or a nitrate-depleted gel (PLA), and forearm SmO₂ and tHb were continuously monitored by using near-infrared spectroscopy. Blood samples were taken before, immediately after exercise, and 20 min after exercise recovery in the PLA and BG conditions. MVC was evaluated at baseline and 20 min after HIE. There was a significant reduction in ΔMVC decline after HIE in the BG condition. Forearm SmO₂ during exercise recovery was significantly greater only after BG supplementation. No significant difference in ETF and tHb were observed between both BG and PLA in response to HIE. Plasma nitrate increased only after BG, whereas the exercise-induced increase in plasma lactate was significantly lower in BG when compared with PLA. In conclusion, BG supplementation may be a good nutritional strategy to improve forearm SmO₂ and prevent force decline in response to exercise in jiu-jitsu athletes.

Acute effect of dietary nitrate on forearm muscle oxygenation, blood volume and strength in older adults: A randomized clinical trial

Both recovery time of post-exercise muscle oxygenation and muscle strength decline with aging. Although beetroot consumption has been shown to improve muscle oxygenation and exercise performance in adults, these effects in the elderly has not been addressed. The aim of the present study was to evaluate the effect of a beetroot-based gel (BG) on muscle O₂ saturation, blood volume (tHb) and handgrip strength in the elderly in response to handgrip exercise. In a randomized crossover double-blind design, twelve older subjects consumed BG (100 g of beetroot-based gel containing ~ 12 mmol nitrate) or PLA (100 g of nitrate-depleted gel nitrate-depleted). The subjects performed a rhythmic handgrip exercise which consisted of a one 1-min set at 30% of the maximal voluntary contraction (MVC) of each subject, followed by a 1 min recovery. The muscle oxygenation parameters and tHb were continuously monitored by using near-infrared spectroscopy. MVC was evaluated at baseline, immediately after exercise, and 30 min afterwards. The muscle O₂ resaturation rate during exercise recovery was greater in the BG when compared to PLA condition (1.43 ± 0.77 vs 1.02 ± 0.48%.s^-1; P < 0.05). Significant increase was observed in tHb during exercise recovery (10.25 ± 5.47 vs 6.72 ± 4.55 μM; P < 0.05) and significant reduction of handgrip strength decline was observed 30 min after exercise in BG (- 0.24 ± 0.18 vs—0.39 ± 0.20 N; P < 0.05). In summary, a single dose of a beetroot-based gel speeds up muscle O₂ resaturation, increases blood volume and improves recovery of handgrip strength after handgrip exercise in older adults.