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1.
Eur J Appl Physiol ; 123(4): 891-899, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36564497

RESUMO

OBJECTIVE: Arterial stiffness and pulsatile central hemodynamics have been shown to affect various aspects of physical function, such as exercise capacity, gait speed, and motor control. The aim of this study was to examine the potential association between arterial stiffness and balance function in healthy younger men and women. METHODS: 112 participants (age = 21 ± 4 years, n = 78 women) underwent measures of arterial stiffness, pulsatile central hemodynamics, balance function and physical fitness in this cross-sectional study. Postural sway was measured in triplicate while participants stood on a foam surface with their eyes closed for 20 s. The average total center of pressure path length from the three trials was used for analysis. Measures of vascular function were estimated using an oscillometric blood pressure device while at rest and included pulse wave velocity (PWV), augmentation index (AIx), and pulse pressure amplification. Measures of physical fitness used as covariates in statistical models included handgrip strength determined from a handgrip dynamometer, lower-body flexibility assessed using a sit-and-reach test, estimated maximal aerobic capacity (VO2max) using heart rate and a step test, and body fat percentage measured from air displacement plethysmography. RESULTS: The results from linear regression indicated that after considering sex, mean arterial pressure, body fat, estimated VO2max, handgrip strength, and sit-and-reach, PWV (ß = 0.44, p < 0.05) and AIx (ß = - 0.25, p < 0.01) were significant predictors of postural sway, explaining 10.2% of the variance. CONCLUSION: Vascular function is associated with balance function in young adults independent of physical fitness. Increased arterial stiffness may negatively influence balance, while wave reflections may be protective for balance.


Assuntos
Rigidez Vascular , Masculino , Humanos , Feminino , Adulto Jovem , Adolescente , Adulto , Rigidez Vascular/fisiologia , Análise de Onda de Pulso/métodos , Estudos Transversais , Força da Mão , Pressão Sanguínea
2.
Heart Vessels ; 37(3): 411-418, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34436657

RESUMO

Endothelial dysfunction may be a phenotypic expression of heart failure (HF). Total brachial artery reactivity (TBAR) is a non-invasive measurement of endothelial function that has been associated with increased risk of cardiovascular outcomes. Limited information is currently available on the impact of TBAR on incident HF and its subtypes. The aim of this study was to investigate whether TBAR is associated with overall incident HF, and the two HF subtypes, HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) in a community-based study. The sample included 5499 participants (45-84 years of age) from the Multi-Ethnic Study of Atherosclerosis who were free of cardiovascular disease at baseline. Brachial artery was imaged via ultrasound after five minutes of cuff occlusion at the right forearm. TBAR was calculated as the difference between maximum and minimum brachial artery diameters following cuff release, divided by the minimum diameter multiplied by 100%. A dichotomous TBAR variable was created based on the median value (below or above 7.9%). Participants with EF ≤ 40% were considered HFrEF and those with EF ≥ 50% were considered HFpEF. Cox proportional hazards regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). Over a mean follow-up period of 12.5 years, incident HF was diagnosed in 250 participants: 98 classified as HFrEF, 106 as HFpEF, and 46 with unknown or borderline EF (41-49%). Crude analysis revealed that those with TBAR below the median had a significantly greater risk of HF (HR 1.46; 95% CI 1.13-1.88, p < 0.01) and HFrEF (HR 1.61; 95% CI 1.07-2.43, p < 0.05). Following adjustment for known HF risk factors (e.g., age, sex, race, blood pressure), the strength of these relationships was attenuated. Borderline significant results were revealed in those with HFpEF (HR 1.43; 95% CI 0.97-2.12, p = 0.06). Kaplan-Meier curves suggest significantly lower risks of developing HF and HFrEF in those with TBAR above the median (log-rank p ≤ 0.05 for both). When examined as a continuous variable, with a cut point of 50% for EF, every 1-standard deviation (9.7%) increase in TBAR resulted in a 19 and 29% decrease in risk of HF (p < 0.05) and HFrEF (p = 0.05), respectively. Lower TBAR values were associated with higher rates of incident HF and HFrEF, suggesting a possible role of endothelial dysfunction in HF pathogenesis. The impact of other known HF risk factors may mediate this relationship, thus further research is warranted.


Assuntos
Aterosclerose , Insuficiência Cardíaca , Aterosclerose/diagnóstico , Aterosclerose/epidemiologia , Artéria Braquial/diagnóstico por imagem , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Humanos , Prognóstico , Fatores de Risco , Volume Sistólico , Função Ventricular Esquerda
3.
Psychosom Med ; 83(3): 265-273, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33534393

RESUMO

OBJECTIVE: Research has consistently found associations between sleep characteristics and cardiovascular disease risk in children, adolescents, and adults. Although primarily investigated in clinical samples (e.g., in those with sleep disorders), greater left ventricular mass is associated with poor sleep quality in nonclinical adult populations as well; however, this has not been evaluated in children or adolescents. Our study aim was to consider the relationship between objectively measured sleep characteristics and left ventricular mass in children. METHODS: We assessed sleep and cardiac structure in a biracial sample of 9- to 11-year-old children (n = 176; 41% White, 59% Black; 50% female). Sleep was assessed with actigraphy for five nights. Cardiac dimensions were assessed using echocardiography. RESULTS: After adjusting for covariates, we found that poor sleep quality was associated with significantly greater left ventricular mass (ß = 0.13, t(167) = 2.14, p = .034, Cohen d = 0.16, for activity during sleep; ß = 0.15, t(167) = 2.43, p = .016, Cohen d = 0.18, for sleep fragmentation). Other cardiac dimensions (namely, relative wall thickness and right ventricular dimension) were also significantly associated with sleep characteristics. Notably, associations did not differ as a function of sex or race. CONCLUSIONS: The present findings are novel and unique because no prior reports have systematically documented the association between poor sleep quality with potentially detrimental cardiac remodeling in a nonclinical sample of children. However, the novelty and importance of these findings require additional research for confirmation.


Assuntos
Ecocardiografia , Transtornos do Sono-Vigília , Actigrafia , Adolescente , Adulto , Criança , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Sono
4.
Eur J Appl Physiol ; 121(12): 3459-3472, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34515867

RESUMO

INTRODUCTION: There are well-established sex differences in central hemodynamic and cardiac adaptations to endurance exercise; however, controversial evidence suggests that excessive endurance exercise may be related to detrimental cardiovascular adaptations in marathoners. PURPOSE: To examine left ventricle (LV) structure, LV function, 24-h central hemodynamics and ventricular-vascular coupling in male and female marathoners and recreationally active adults. METHODS: 52 marathoners (41 ± 5 years, n = 28 female, completed 6 ± 1 marathons/3 years) and 49 recreationally active controls (42 ± 5 years, n = 25 female) participated in the study. Three-Dimensional Echocardiography (3DE) was used to measure LV mass index and LV longitudinal (LS) circumferential (CS), area (AS), and radial strain (RS). An ambulatory blood pressure (BP) cuff was used to measure 24-h central hemodynamics (BP, pulse wave velocity, PWV, wave reflection index, RIx). Hemodynamic and 3DE measures were combined to derive the ratio of arterial elastance (Ea) to ventricular elastance (Elv) as a global measure of ventricular-vascular coupling. RESULTS: There were no sex or group differences in LS, CS, AS, and RS (p > 0.05). Females marathoners had similar aortic BP (116 ± 9 vs. 113 ± 1 mmHg), and PWV (5.9 ± 0.5 vs. 5.9 ± 1.1 m/s) compared to female controls but lower aSBP (116 ± 9 vs. 131 ± 10 mmHg) and PWV (5.9 ± 0.5 vs. 6.2 ± 0.5 m/s) compared to male marathoners (p < 0.05). Female marathoners had lower Ea/Elv than female controls (0.67 ± 0.20 vs. 0.93 ± 0.36) and male marathoners (0.67 ± 0.20 vs. 0.85 ± 0.42, p < 0.05). CONCLUSIONS: Women that have completed multiple marathons do not have reduced LV function or increased aortic stiffness and may have better ventricular-vascular coupling compared to male marathoners and their female untrained counterparts.


Assuntos
Adaptação Fisiológica , Hemodinâmica/fisiologia , Corrida de Maratona/fisiologia , Função Ventricular Esquerda/fisiologia , Adulto , Monitorização Ambulatorial da Pressão Arterial , Ecocardiografia Tridimensional , Feminino , Humanos , Masculino , Análise de Onda de Pulso , Rigidez Vascular
5.
Int J Sports Med ; 42(5): 419-424, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32920803

RESUMO

The purpose of this study was to determine the relationship between strength and atherosclerotic cardiovascular disease (CVD) risk in young women. Carotid intima-media thickness (IMT) and extra-media thickness (EMT) were used as measures of subclinical atherosclerosis and CVD risk. Muscular strength, IMT, and EMT were measured in 70 young women (mean age=21±4 years). Strength was determined using a handgrip dynamometer and expressed relative to body mass. IMT and EMT were measured using ultrasonography of the left common carotid artery. Objectively measured moderate-vigorous physical activity (MVPA) was assessed with accelerometry. Higher relative handgrip strength was associated with lower IMT (r=-0.23; p<0.05) and lower EMT (r=-0.27; p<0.05). Associations between relative handgrip strength and IMT (r=-0.24) as well as EMT (r=-0.25) remained significant after adjusting for potential confounders including traditional CVD risk factors and MVPA (p<0.05). These results show that there is an inverse association between handgrip strength with carotid IMT and EMT in young women. Muscular strength may reduce CVD risk in young women via favorable effects on subclinical carotid atherosclerosis independent of physical activity.


Assuntos
Aterosclerose/diagnóstico por imagem , Aterosclerose/fisiopatologia , Espessura Intima-Media Carotídea , Força da Mão , Acelerometria , Adolescente , Adulto , Doenças Assintomáticas , Índice de Massa Corporal , Artérias Carótidas/diagnóstico por imagem , Feminino , Humanos , Medição de Risco , Adulto Jovem
6.
Eur J Appl Physiol ; 120(12): 2635-2647, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32880701

RESUMO

PURPOSE: Aortic stiffness may affect shear patterns in the peripheral vasculature. This study examined if sprint exercise, which typically increases aortic stiffness is associated with increased peripheral retrograde blood flow and impaired microvascular function. METHODS: Twenty participants (10 women; age: 27 ± 5 years) underwent arterial stiffness, shear rate, and microvascular function assessment at three time points: baseline; following time control; ~ 2 min post a 30-s cycle ergometer sprint against 7.0% body mass. Aortic stiffness was assessed using carotid-femoral pulse wave velocity (cfPWV). Superficial femoral artery (SFA) diameter and blood velocity were assessed using Doppler-ultrasound and were used to calculate shear rates and resistance index (RI). SFA wave reflections were obtained via wave intensity analysis. Vastus medialis microvascular function was measured as tissue saturation index reactivity pre-post exercise via near-infrared spectroscopy. RESULTS: cfPWV increased by + 0.8 ± 0.7 m·s-1 following exercise (p < 0.001). Retrograde shear was reduced following exercise compared with time control (- 4.9 ± 3.8 s-1; p < 0.001), while tissue saturation index was increased post-exercise from baseline (+ 2.3 ± 4.6%; p = 0.04). Reductions in SFA wave reflections (- 1.70 ± 1.96 aU) and RI (- 0.17 ± 0.13 aU) were also noted following exercise (p < 0.001). CONCLUSION: These data suggest sprint exercise-mediated changes in peripheral shear patterns and microvascular function in the exercised vasculature occur independent from increases in aortic stiffness. Exercise-induced reductions in SFA retrograde shear may be related to decreased wave reflections and peripheral vascular resistance.


Assuntos
Aorta/fisiologia , Exercício Físico/fisiologia , Artéria Femoral/fisiologia , Rigidez Vascular/fisiologia , Adulto , Pressão Sanguínea/fisiologia , Feminino , Humanos , Masculino , Análise de Onda de Pulso/métodos , Ultrassonografia/métodos , Resistência Vascular/fisiologia
7.
Eur J Appl Physiol ; 119(8): 1809-1818, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31190212

RESUMO

INTRODUCTION: Retrograde shear causes endothelial damage and is pro-atherogenic. The purpose of our study was to examine the impact of vascular remodeling from habitual exercise training on acute changes in retrograde shear and microvascular oxygenation (SMO2) induced via 30 min of external compression. METHODS: Participants included 11 exercise trained (ET) men (Division I track athletes; age 20 ± 3 years) and 18 recreationally active (RA) men (age 23 ± 5 years). Near-infrared spectroscopy (NIRS) was used to measure vastus medialis SMO2. Doppler-ultrasound was used to assess SFA intima-media thickness, diameter and flow velocity to derive retrograde shear. Vascular measures were made at baseline (BASELINE), during a sham condition (calf compression to 5 mmHg, SHAM) and during the experimental condition (calf compression to 60 mmHg, EXP). RESULTS: Compared to RA, ET had larger SFA diameters (0.66 ± 0.06 vs 0.58 ± 0.06 cm, p < 0.05) and lower SFA IMT (0.33 ± 0.03 vs 0.36 ± 0.07 mm, p < 0.05). Retrograde shear increased similarly in both groups during EXP (p < 0.05) but ET men had lower overall retrograde shear during the conditions (BASELINE 75.8 ± 26.8 vs EXP 88.2 ± 16.9 s-1) compared to RA men (BASELINE 84.4 ± 23.3 vs EXP 106.4 ± 19.6 s-1p < 0.05). There was a similar increase in SMO2 from BASELINE to SHAM (ET + 8.1 ± 4.8 vs RA + 6.4 ± 9.7%) and BASELINE to EXP (ET + 8.7 ± 6.4 vs RA + 7.1 ± 9.0%) in both groups. CONCLUSION: Beneficial vascular remodeling in ET men is associated with lower retrograde shear during external compression. Acute increases in retrograde shear with external compression do not detrimentally impact microvascular oxygenation.


Assuntos
Exercício Físico , Hemodinâmica , Músculo Esquelético/fisiologia , Consumo de Oxigênio , Reperfusão , Adolescente , Adulto , Bandagens Compressivas , Endotélio Vascular/fisiologia , Artéria Femoral/fisiologia , Humanos , Masculino , Microvasos/fisiologia , Músculo Esquelético/irrigação sanguínea
8.
Int J Mol Sci ; 20(5)2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30866573

RESUMO

Oxidative stress resulting from decreased antioxidant protection and increased reactive oxygen and nitrogen species (RONS) production may contribute to muscle mass loss and dysfunction during aging. Curcumin is a phenolic compound shown to upregulate antioxidant defenses and directly quench RONS in vivo. This study determined the impact of prolonged dietary curcumin exposure on muscle mass and function of aged rats. Thirty-two-month-old male F344xBN rats were provided a diet with or without 0.2% curcumin for 4 months. The groups included: ad libitum control (CON; n = 18); 0.2% curcumin (CUR; n = 18); and pair-fed (PAIR; n = 18) rats. CUR rats showed lower food intake compared to CON, making PAIR a suitable comparison group. CUR rats displayed larger plantaris mass and force production (vs. PAIR). Nuclear fraction levels of nuclear factor erythroid-2 related-factor-2 were greater, and oxidative macromolecule damage was lower in CUR (vs. PAIR). There were no significant differences in measures of antioxidant status between any of the groups. No difference in any measure was observed between CUR and CON rats. Thus, consumption of curcumin coupled with reduced food intake imparted beneficial effects on aged skeletal muscle. The benefit of curcumin on aging skeletal muscle should be explored further.


Assuntos
Curcumina/administração & dosagem , Músculo Esquelético/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Envelhecimento , Animais , Curcumina/farmacologia , Suplementos Nutricionais , Ingestão de Alimentos , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Modelos Animais , Músculo Esquelético/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Ratos
9.
Eur J Appl Physiol ; 118(5): 937-946, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29455431

RESUMO

INTRODUCTION: Aerobic exercise has a favorable effect on systemic vascular function, reducing both central (large elastic artery) and peripheral (smaller muscular artery) stiffness. The effects of resistance exercise (RE) on arterial stiffness are more complex. Acute RE increases central artery stiffness while decreasing peripheral stiffness. To date, the majority of studies have been performed in predominantly male participants. PURPOSE: To examine the effect of acute RE on central and peripheral arterial stiffnesses in women, a secondary purpose was to explore the influence of cyclic changes in estrogen status across the menstrual cycle on the arterial response to acute RE. METHODS: 18 healthy women [28 ± 7 years, body mass index (BMI) 22.6 ± 2.9 kg/m2] completed an acute RE bout during the early follicular and the early luteal phase of their menstrual cycle. Salivary 17ß-Estradiol concentration was measured during each phase, using a passive drool technique. Pulse-wave velocity (PWV) was obtained from the carotid-femoral and carotid-radial pulse sites to measure central and peripheral stiffness, respectively, using applanation tonometry. PWV was measured at rest, immediately, 10, 20, and 30 min post-RE. RESULTS: 17ß-Estradiol concentration was significantly lower in the early follicular vs. the early luteal phase of the menstrual cycle (1.78 ± 0.51 vs. 2.40 ± 0.26 pg/ml, p = 0.01). Central PWV significantly increased (p < 0.05) and peripheral PWV significantly decreased (p < 0.05) post-RE in both the early follicular and early luteal phases. No phase-by-time interaction was detected for either vascular segment (p > 0.05). CONCLUSION: Women experience increases in central arterial stiffness and reductions in peripheral arterial stiffness following acute RE. Menstrual cycle phase may not influence changes in arterial stiffness in response to acute RE.


Assuntos
Ciclo Menstrual , Treinamento Resistido , Rigidez Vascular , Adolescente , Adulto , Artérias Carótidas/fisiologia , Estradiol/metabolismo , Feminino , Artéria Femoral/fisiologia , Humanos
10.
Eur J Appl Physiol ; 118(10): 2203-2211, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30056548

RESUMO

INTRODUCTION: While resistance exercise (RE) is known to be beneficial for overall health, one bout of RE acutely increases aortic stiffness and pulse pressure (PP). Increases in aortic stiffness and PP in a setting of aging has been shown to detrimentally impact cognitive function. This study examined whether increased aortic stiffness and PP from an acute bout of RE is associated with cognitive function. METHODS: Thirty-five participants (21 ± 2 years) underwent cognitive testing before and after either an acute bout of RE or a non-exercise time-control condition. Cognitive function was assessed as reaction time and accuracy during memory recognition, attention (Flanker) and working memory (N-back) tasks. Aortic stiffness and PP were measured via pulse wave velocity (PWV) and pulse wave analysis, respectively, using a brachial oscillometric device. RESULTS: There were significant increases in aortic PWV and aortic PP following RE (p < 0.05) with no change in PWV or PP following the non-exercise control condition (p > 0.05). There was no change in accuracy metrics (% hits) across conditions for any cognitive task (p > 0.05). There was a condition-by-time interaction for reaction time for the memory task (p < 0.05) driven by a significant decrease in reaction times following RE (p < 0.05) with no change in reaction time following the non-exercise control (p > 0.05). CONCLUSION: Functional increases in aortic stiffness and pulse pressure following acute RE occur in the absence of detrimental changes in cognitive function in young, healthy adults.


Assuntos
Pressão Sanguínea , Cognição/fisiologia , Treinamento Resistido , Rigidez Vascular , Adolescente , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Adulto Jovem
11.
Adapt Phys Activ Q ; 35(4): 361-380, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30369246

RESUMO

Despite having the desire to become physically active as a family, parents of children with visual impairments often lack the skills and resources needed to provide appropriate physical activities (PAs) for their children. The purpose of this study was to explore the intentions of parents of children with visual impairments toward including their children in PAs after participating in a PA program. In this descriptive qualitative study, the participants were 10 parents of children with visual impairments. A series of workshops were designed to provide parents with the skills and resources needed to promote PA for their family. Upon completion of the workshops, parents took part in one-on-one semistructured interviews that were subsequently transcribed and analyzed using a thematic line-by-line process. Two interdependent themes emerged from the data analyses: (a) eye-opening experiences and (b) transformed, more hopeful, and optimistic outlook. The results revealed that through the PA intervention, parents learned teaching strategies that were intended to increase their PA opportunities and garnered resources that allowed them to teach their children to participate in PA.


Assuntos
Crianças com Deficiência/psicologia , Exercício Físico , Conhecimentos, Atitudes e Prática em Saúde , Intenção , Pais/psicologia , Pessoas com Deficiência Visual/psicologia , Adulto , Criança , Pré-Escolar , Humanos , Pessoa de Meia-Idade , Pesquisa Qualitativa
12.
J Pediatr ; 180: 62-67, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27817877

RESUMO

OBJECTIVE: To investigate racial differences in central blood pressure and vascular structure/function as subclinical markers of atherosclerotic cardiovascular disease in children. STUDY DESIGN: This cross-sectional study recruited 54 African American children (18 female, 36 male; age 10.5 ± 0.9 years) and 54 white children (27 female, 26 male; age 10.8 ± 0.9 years) from the Syracuse City community as part of the Environmental Exposures and Child Health Outcomes study. Participants underwent blood lipid and vascular testing on 2 separate days. Carotid artery intima-media thickness and aortic stiffness were measured by ultrasonography and carotid-femoral pulse wave velocity, respectively. Blood pressure was assessed at the brachial artery and estimated in the carotid artery using applanation tonometry. RESULTS: African American children had significantly higher pulse wave velocity (4.8 ± 0.8 m/s) compared with white children (4.2 ± 0.7 m/s; P < .05), which remained significant after adjustment for confounding variables including socioeconomic status. African American children had significantly higher intima-media thickness (African American 0.41 ± 0.06, white 0.39 ± 0.05 mm), and carotid systolic blood pressure (African American 106 ± 11, white 102 ± 8 mm Hg; P < .05) compared with white children, although these racial differences were no longer present after covariate adjustments for height. CONCLUSIONS: Racial differences in aortic stiffness are present in childhood. Our findings suggest that racial differences in subclinical cardiovascular disease occur earlier than previously recognized.


Assuntos
Aorta , Negro ou Afro-Americano , Espessura Intima-Media Carotídea , Rigidez Vascular , População Branca , Criança , Estudos Transversais , Feminino , Humanos , Masculino
13.
Clin Auton Res ; 27(6): 417-421, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29052078

RESUMO

OBJECTIVE: Acute resistance exercise has been shown to reduce brachial endothelial function. Whether there are concomitant reductions in carotid endothelial function remains unexplored. METHODS: Cold pressor test-mediated vasodilation of the carotid artery was used to assess carotid endothelial function in 15 young and healthy participants (age 26 ± 1 years, body mass index 24 ± 1 kg/m2) after acute resistance exercise or an inactive time control condition. RESULTS: Acute resistance exercise had no effect on the cold pressor test-mediated vasodilation compared to time control (5.8 ± 0.8 vs 6.2 ± 0.9% dilation, p > 0.05). INTERPRETATION: Carotid endothelial function may not be compromised following acute resistance exercise in young healthy adults.


Assuntos
Fibras Adrenérgicas/fisiologia , Pressão Sanguínea/fisiologia , Artérias Carótidas/inervação , Artérias Carótidas/fisiologia , Exercício Físico/fisiologia , Treinamento Resistido/métodos , Adulto , Temperatura Baixa , Feminino , Humanos , Masculino , Fluxo Sanguíneo Regional/fisiologia , Vasodilatação/fisiologia
15.
Nitric Oxide ; 52: 49-55, 2016 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-26679695

RESUMO

UNLABELLED: Acute hypoxia results in local vasodilation that may temporarily unload the left ventricle (LV) through nitric oxide (NO)-mediated mechanisms. Whether increasing NO levels augments LV unloading and improves ventricular-vascular coupling in hypoxia remains unknown. PURPOSE: Investigate the effect of acute nitrate ingestion on central hemodynamic load in hypoxia. METHODS: 20 Healthy men (23 ± 3 yrs, BMI 24.6 ± 2.8 kg m(-2)) consumed 70 mL of either a) 0.45 g nitrate (NIT) or b) an inert placebo (PLA) prior to 105 min of normobaric hypoxia (11.6 ± 0.1%) in this randomized, double-blind, crossover-design study. Wave reflection index (RIX; ratio of forward to reflected wave pressure), augmentation index (AIX75) and pulse wave velocity were calculated as measures of wave reflection magnitude and aortic stiffness, respectively, from the aortic blood pressure (BP) waveform. LV wasted pressure effort (WPE) was calculated as an index of LV work due to wave reflections. Subendocardial viability ratio (SEVR) was assessed a measure of myocardial O2 supply/demand ratio. RESULTS: Aortic diastolic BP decreased in hypoxia compared to normoxia (p < 0.05). Aortic RIX, AIX75, and LV WPE significantly decreased in hypoxia compared to normoxia (p < 0.05). Aortic systolic BP, SEVR, and PWV were unaffected by hypoxia (p > 0.05). Compared to placebo, nitrate ingestion did not significantly alter central hemodynamics in hypoxia (p > 0.05). CONCLUSIONS: Acute hypoxic exposure unloads the LV (WPE, AIX75, and RIX) without disturbing myocardial O2 supply-demand ratio (SEVR). Reductions in LV work with hypoxia are likely due to reductions in pressure from wave reflections as hypoxia had negligible effects on aortic stiffness. Nitrate ingestion did not affect the central hemodynamic response to acute systemic hypoxia.


Assuntos
Ventrículos do Coração/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Hipóxia/metabolismo , Nitratos/administração & dosagem , Nitratos/farmacologia , Função Ventricular Esquerda/efeitos dos fármacos , Administração Oral , Adulto , Pressão Arterial/efeitos dos fármacos , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Adulto Jovem
16.
Vasc Med ; 20(3): 222-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25939655

RESUMO

This study examined the effects of moderate exercise-induced heat stress (EIHS) on vascular function, central hemodynamic load and indices of coronary perfusion. Vascular-hemodynamic measures were collected in 12 healthy men (aged 22±3 years) pre and post 100 minutes of moderate, intermittent exercise in two randomized conditions: heat stress (HS; wearing firefighter personal protective equipment (PPE)), and no heat stress (NHS; wearing a cooling shirt and equivalent PPE weight). Aortic blood pressure, reflected wave pressure (Pb), systolic (SPTI) and diastolic pressure time-integral (DPTI), and aortic stiffness were assessed before and after each condition. SPTI was significantly greater, and DPTI and Pb were significantly lower for HS-post compared to NHS-post (p<0.05). Pulse wave velocity was not different between conditions. In conclusion, EIHS does not affect aortic stiffness, but increases indices of myocardial work and reduces indices of coronary perfusion which may be related to chronotropic responses to EIHS. The mismatch between oxygen demand and oxygen supply may increase cardiac vulnerability to ischemia during strenuous work in the heat.


Assuntos
Vasos Sanguíneos/fisiologia , Exercício Físico/fisiologia , Coração/fisiologia , Resposta ao Choque Térmico/fisiologia , Hemodinâmica , Pressão Sanguínea , Circulação Coronária/fisiologia , Humanos , Masculino , Rigidez Vascular , Adulto Jovem
17.
Eur J Appl Physiol ; 115(5): 1037-45, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25543325

RESUMO

PURPOSE: Investigate the effects of acute high-intensity exercise on common carotid artery (CCA) dimensions, stiffness, and wave intensity. METHODS: Fifty-five healthy men and women (22 ± 5 year; 24.5 ± 2.7 kg m(-2)) underwent 30 s of high-intensity cycling (HIC; Wingate anaerobic test). CCA diameter, stiffness [ß-stiffness, Elastic Modulus (E p)], pulsatility index (PI), forward wave intensities [due to LV contraction (W 1) and LV suction (W 2)], and reflected wave intensity [negative area (NA)] were assessed using a combination of Doppler ultrasound, wave intensity analysis, and applanation tonometry at baseline and immediately post-HIC. RESULTS: CCA ß-stiffness, E p, PI and pulse pressure increased significantly immediately post-HIC (p < 0.05). CCA diameter decreased acutely post-HIC (p < 0.05). There were also significant increases in W 1 and NA and a significant decrease in W 2 (p < 0.05). A significant correlation was found between change in W 1 and PI (r = 0.438, p < 0.05), from rest to recovery as well as a significant inverse correlation between W 2 and PI (r = -0.378, p < 0.05). Change in PI was not associated with change in CCA stiffness or NA (p > 0.05). CONCLUSIONS: Acute HIC results in CCA constriction and increases in CCA stiffness along with increases in hemodynamic pulsatility. The increase in pulsatility may be due to a combination of increased forward wave intensity from increased LV contractility into a smaller vessel (i.e. impaired matching of diameter and flow) coupled with reduced LV suction.


Assuntos
Ciclismo/fisiologia , Pressão Sanguínea/fisiologia , Artérias Carótidas/fisiologia , Hemodinâmica/fisiologia , Esforço Físico/fisiologia , Adolescente , Adulto , Velocidade do Fluxo Sanguíneo/fisiologia , Artérias Carótidas/diagnóstico por imagem , Feminino , Humanos , Masculino , Ultrassonografia , Adulto Jovem
18.
Am J Physiol Heart Circ Physiol ; 306(1): H60-8, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-24186094

RESUMO

African-American (AA) men have higher arterial stiffness and augmentation index (AIx) than Caucasian-American (CA) men. Women have greater age-associated increases in arterial stiffness and AIx than men. This study examined racial and sex differences in arterial stiffness and central hemodynamics at rest and after an acute bout of maximal exercise in young healthy individuals. One hundred young, healthy individuals (28 AA men, 24 AA women, 25 CA men, and 23 CA women) underwent measurements of aortic blood pressure (BP) and arterial stiffness at rest and 15 and 30 min after an acute bout of graded maximal aerobic exercise. Aortic BP and AIx were derived from radial artery applanation tonometry. Aortic stiffness (carotid-femoral) was measured via pulse wave velocity. Aortic stiffness was increased in AA subjects but not in CA subjects (P < 0.05) after an acute bout of maximal cycling exercise, after controlling for body mass index. Aortic BP decreased after exercise in CA subjects but not in AA subjects (P < 0.05). Women exhibited greater reductions in AIx after maximal aerobic exercise compared with men (P < 0.05). In conclusion, race and sex impact vascular and central hemodynamic responses to exercise. Young AA and CA subjects exhibited differential responses in central stiffness and central BP after acute maximal exercise. Premenopausal women had greater augmented pressure at rest and after maximal aerobic exercise than men. Future research is needed to examine the potential mechanisms.


Assuntos
População Negra , Pressão Sanguínea , Exercício Físico , Rigidez Vascular , População Branca , Adolescente , Adulto , Fatores Etários , Feminino , Humanos , Masculino , Pré-Menopausa/fisiologia , Fatores Sexuais
19.
Ann Hum Biol ; 41(5): 477-80, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24180292

RESUMO

This study investigated the relationship of cardiorespiratory fitness (CRF) with incident metabolic syndrome in 810 middle aged Korean men. All subjects were free of metabolic syndrome at baseline examination. The metabolic syndrome was defined by NCEP criteria and CRF was directly measured by peak oxygen uptake during a treadmill test. During an average of 3.3 years of follow-up, 155 (19.1%) men developed the metabolic syndrome. The incidence of metabolic syndrome was inversely associated with CRF quartiles (p < 0.05). The relative risk (RR) of incident metabolic syndrome in the lowest CRF quartile vs the highest CRF quartile was 1.67 (95% CI = 1.07-2.60) after adjustment for covariates. Each metabolic equivalent (MET) increment in peak oxygen consumption was associated with a 17% (RR = 0.83, 95% CI = 0.73-0.94) lower incidence of metabolic syndrome. These results demonstrate that cardiorespiratory fitness was associated with the incidence of metabolic syndrome independent of covariates in middle aged Korean men.


Assuntos
Síndrome Metabólica/epidemiologia , Aptidão Física , Adulto , Teste de Esforço , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , República da Coreia/epidemiologia
20.
PLoS One ; 19(3): e0298366, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38498456

RESUMO

Variable military service-related experiences, such as combat exposure, psychiatric disorders (PD), and traumatic brain injuries (TBI), may differentially affect the likelihood of having health care professional-identified high blood pressure (i.e., hypertension). PURPOSE: Compare the odds of self-reported hypertension among non-combat and combat veterans with and without PD/TBI to non-veterans and each other. METHODS: We used data from men from the 2011 Behavioral Risk Factor Surveillance System and distinguished: non-veterans (n = 21,076); non-combat veterans with no PD/TBI (n = 3,150); combat veterans with no PD/TBI (n = 1,979); and veterans (combat and non-combat) with PD and/or TBI (n = 805). Multivariable, hierarchical logistic regression models included exogenous demographic, socioeconomic attainment and family structure, health behavior and conditions, and methodological control variables. RESULTS: One-third of men reported having been told at least once by a medical professional that they had high blood pressure. Bivariate analyses indicated that each veteran group had a higher prevalence of self-reported hypertension than non-veterans (design-based F = 45.2, p<0.001). In the fully adjusted model, no statistically significant differences in the odds of self-reported hypertension were observed between non-veterans and: non-combat veterans without PD/TBI (odds ratio [OR] = 0.92); combat veterans without PD/TBI (OR = 0.87); veterans with PD and/or TBI (OR = 1.35). However, veterans with PD and/or TBI had greater odds of reporting hypertension than both combat and non-combat veterans without PD/TBI (p<0.05). DISCUSSION: Military service-related experiences were differentially associated with a survey-based measure of hypertension. Specifically, veterans self-reporting PD and/or TBI had significantly higher odds of self-reporting hypertension (i.e., medical provider-identified high blood pressure).


Assuntos
Lesões Encefálicas Traumáticas , Hipertensão , Transtornos de Estresse Pós-Traumáticos , Veteranos , Masculino , Humanos , Veteranos/psicologia , Sistema de Vigilância de Fator de Risco Comportamental , Lesões Encefálicas Traumáticas/epidemiologia , Lesões Encefálicas Traumáticas/psicologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Hipertensão/epidemiologia
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