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1.
Geroscience ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39014131

RESUMO

Frailty reflects age-related damage to multiple physiological systems. Executive dysfunction is often a presenting symptom of diseases characterized by cognitive impairment. A decline in cardiovascular health is associated with worse executive function. We tested the hypothesis that higher frailty would be associated with executive dysfunction and that cardiovascular health would mediate this relationship. Middle- and older-aged adults at baseline (n = 29,591 [51% female]) and 3-year follow-up (n = 25,488 [49% females]) from the Canadian Longitudinal Study on Aging (comprehensive cohort) were included. Frailty was determined at baseline from a 61-item index, a cumulative cardiovascular health score was calculated from 30 variables at baseline, and participants completed a word-color Stroop task as an assessment of executive function. Multiple linear regressions and mediation analyses of cardiovascular health were conducted between frailty, Stroop interference-condition reaction time, and cardiovascular health in groups stratified by both age and sex (middle-aged males [MM], middle-aged females [MF], older-aged males [OM], older-aged females [OF]). Frailty (MM, 0.15 ± 0.05; MF, 0.16 ± 0.06; OM, 0.21 ± 0.06; OF, 0.23 ± 0.06) was negatively associated with cardiovascular health (MM, 0.12 ± 0.08; MF, 0.11 ± 0.07; OM, 0.20 ± 0.10; OF, 0.18 ± 0.09; ß > 0.037, p < 0.001), as well as the Stroop reaction time at 3-year follow-up (MM, 23.7 ± 7.9; MF, 23.1 ± 7.3; OM, 32.9 ± 13.1; OF, 30.9 ± 12.0; ß > 2.57, p < 0.001) across all groups when adjusted for covariates. Cardiovascular health was a partial (~ 10%) mediator between frailty and reaction time, aside from MFs. In conclusion, higher frailty levels are associated with executive dysfunction, which was partially mediated by cardiovascular health. Strategies to improve frailty and better cardiovascular health may be useful for combatting the age-related decline in executive function.

2.
Age Ageing ; 53(6)2024 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-38935532

RESUMO

BACKGROUND: The Osteoarthritis Initiative (OAI) evaluates the development and progression of osteoarthritis. Frailty captures the heterogeneity in aging. Use of this resource-intensive dataset to answer aging-related research questions could be enhanced by a frailty measure. OBJECTIVE: To: (i) develop a deficit accumulation frailty index (FI) for the OAI; (ii) examine its relationship with age and compare between sexes, (iii) validate the FI versus all-cause mortality and (iv) compare this association with mortality with a modified frailty phenotype. DESIGN: OAI cohort study. SETTING: North America. SUBJECTS: An FI was determined for 4,755/4,796 and 4,149/4,796 who had a valid FI and frailty phenotype. METHODS: Fifty-nine-variables were screened for inclusion. Multivariate Cox regression evaluated the impact of FI or phenotype on all-cause mortality at follow-up (up to 146 months), controlling for age and sex. RESULTS: Thirty-one items were included. FI scores (0.16 ± 0.09) were higher in older adults and among females (both, P < 0.001). By follow-up, 264 people had died (6.4%). Older age, being male, and greater FI were associated with a higher risk of all-cause mortality (all, P < 0.001). The model including FI was a better fit than the model including the phenotype (AIC: 4,167 vs. 4,178) and was a better predictor of all-cause mortality than the phenotype with an area under receiver operating characteristic curve: 0.652 vs. 0.581. CONCLUSION: We developed an FI using the OAI and validated it in relation to all-cause mortality. The FI may be used to study aging on clinical, functional and structural aspects of osteoarthritis included in the OAI.


Assuntos
Fragilidade , Avaliação Geriátrica , Osteoartrite , Humanos , Masculino , Feminino , Idoso , Fragilidade/mortalidade , Fragilidade/diagnóstico , Osteoartrite/mortalidade , Osteoartrite/diagnóstico , Avaliação Geriátrica/métodos , Pessoa de Meia-Idade , Idoso Fragilizado/estatística & dados numéricos , Idoso de 80 Anos ou mais , Fatores Etários , Reprodutibilidade dos Testes , Valor Preditivo dos Testes , Fatores Sexuais , América do Norte/epidemiologia , Fatores de Risco , Fenótipo , Medição de Risco/métodos , Causas de Morte
3.
Front Sports Act Living ; 6: 1393214, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38835704

RESUMO

Executive functions are among the first cognitive abilities to decline with age and age-related executive function slowing predisposes older adults to cognitive disorders and disease. Intermittent Lifestyle Physical Activity (ILPA) reflects brief, unplanned activity that occurs during routine daily activities and is operationalized as activity bouts <60s. Our understanding of short bouts of habitual physical activity and executive functions is limited. We tested the hypothesis that greater amounts of ILPA in moderate and vigorous intensity domains would be associated with better executive function in older adults. Forty older adults (26 females, 68 ± 6, >55 years; body mass index: 26.6 ± 4.3 kg/m2) completed a Trail-Making-Task and wore an activPAL 24-hr/day for 6.2 ± 1.8-days. For each intensity, total time and time spent in bouts <60 s were determined. Trail A (processing speed) and Trail B (cognitive flexibility) were completed in 25.8 ± 8.2 s and 63.2 ± 26.2 s, respectively. Non-parametric Spearman's rank correlations report that moderate ILPA (3.2 ± 3.2 min/day) and total-moderate physical activity (20.1 ± 16.0 min/day) were associated with faster Trail A (total-moderate physical activity: ρ=-0.48; moderate-ILPA: ρ = -0.50; both, p < 0.003) and Trail B time (total-moderate physical activity: ρ = 0.36; moderate-ILPA: ρ = -0.46; both, p < 0.020). However, the results show no evidence of an association with either vigorous physical activity or light physical activity (total time or ILPA bouts: all, p > 0.180). Moderate physical activity accumulated in longer bouts (>60 s) was not associated with Trail B time (p = 0.201). Therefore, more total moderate physical activity and shorter bouts (<60 s) may result in better executive functions in older adults.

4.
Auton Neurosci ; 254: 103193, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38852226

RESUMO

PURPOSE: The nadir pressure responses to cardiac cycles absent of muscle sympathetic nerve activity (MSNA) bursts (or non-bursts) are typically reported in studies quantifying sympathetic transduction, but the information gained by studying non-bursts is unclear. We tested the hypothesis that longer sequences of non-bursts (≥8 cardiac cycles) would be associated with a greater nadir diastolic blood pressure (DBP) and that better popliteal artery function would be associated with an augmented reduction in DBP. METHODS: Resting beat-by-beat DBP (via finger photoplethysmography) and common peroneal nerve MSNA (via microneurography) were recorded in 39 healthy, adults (age 23.4 ± 5.3 years; 19 females). For each cardiac cycle absent of MSNA bursts, the mean nadir DBP (ΔDBP) during the 12 cardiac cycles following were determined, and separate analyses were conducted for ≥8 or < 8 cardiac cycle sequences. Popliteal artery endothelial-dependent (via flow-mediated dilation; FMD) and endothelial-independent vasodilation (via nitroglycerin-mediated dilation; NMD) were determined. RESULTS: The nadir DBP responses to sequences ≥8 cardiac cycles were larger (-1.40 ± 1.27 mmHg) than sequences <8 (-0.38 ± 0.46 mmHg; p < 0.001). In adjusting for sex and burst frequency (14 ± 8 bursts/min), larger absolute or relative FMD (p < 0.01), but not NMD (p > 0.53) was associated with an augmented nadir DBP. This overall DBP-FMD relationship was similar in sequences ≥8 (p = 0.04-0.05), but not <8 (p > 0.72). CONCLUSION: The DBP responses to non-bursts, particularly longer sequences, were inversely associated with popliteal endothelial function, but not vascular smooth muscle sensitivity. This study provides insight into the information gained by quantifying the DBP responses to cardiac cycles absent of MSNA.

5.
Am J Physiol Heart Circ Physiol ; 327(1): H108-H117, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38758123

RESUMO

Frailty reflects the heterogeneity in aging and may lead to the development of hypertension and heart disease, but the frailty-cardiovascular relationship and whether physical activity modifies this relationship in males and females are unclear. We tested whether higher frailty was positively associated with hypertension and heart disease in males and females and whether habitual movement mediated this relationship. The relationship between baseline frailty with follow-up hypertension and heart disease was investigated using the Canadian Longitudinal Study on Aging at 3-year follow-up data (males: n = 13,095; females: n = 13,601). Frailty at baseline was determined via a 73-item deficit-based index, activity at follow-up was determined via the Physical Activity Scale for the Elderly, and cardiovascular function was self-reported. Higher baseline frailty level was associated with a greater likelihood of hypertension and heart disease at follow-up, with covariate-adjusted odds ratios of 1.08-1.09 (all, P < 0.001) for a 0.01 increase in frailty index score. Among males and females, sitting time and strenuous physical activity were independently associated with hypertension, with these activity behaviors being partial mediators (except male-sitting time) for the frailty-hypertension relationship (explained 5-10% of relationship). The strength of this relationship was stronger among females. Only light-moderate activity partially mediated the relationship (∼6%) between frailty and heart disease in females, but no activity measure was a mediator for males. Higher frailty levels were associated with a greater incidence of hypertension and heart disease, and strategies that target increases in physical activity and reducing sitting may partially uncouple this relationship with hypertension, particularly among females.NEW & NOTEWORTHY Longitudinally, our study demonstrates that higher baseline frailty levels are associated with an increased risk of hypertension and heart disease in a large sample of Canadian males and females. Movement partially mediated this relationship, particularly among females.


Assuntos
Envelhecimento , Exercício Físico , Fragilidade , Hipertensão , Humanos , Masculino , Feminino , Hipertensão/fisiopatologia , Hipertensão/epidemiologia , Hipertensão/diagnóstico , Idoso , Fragilidade/fisiopatologia , Fragilidade/epidemiologia , Fragilidade/diagnóstico , Canadá/epidemiologia , Estudos Longitudinais , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Fatores Sexuais , Idoso Fragilizado , Pressão Sanguínea , Fatores Etários , Fatores de Risco , Cardiopatias/epidemiologia , Cardiopatias/fisiopatologia , Medição de Risco
6.
Geroscience ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38722469

RESUMO

Cardiovascular endurance and muscular fitness seem to impact specific cognitive components in older females. However, it remains uncertain whether these relate to executive functions or if these correlations are limited to specific physical fitness indicators. This study aimed to determine the association between specific physical fitness components and executive functions in community-dwelling older females. Thirty-five cognitively healthy community-dwelling older females (71.5 ± 5.7 years) underwent a series of physical fitness tests. These included the handgrip strength test (HGT), the 6-min walk test (6MWT), the 8-foot up-and-go test (8FUGT), and the chair stand test (CST). Participants also completed trail A and trail B of the cognitive trail making test. Results showed that trail B reaction time had a negative association with both HGT (r = - 0.502; p = 0.002) and 6MWT (r = - 0.543; p < 0.001). Together, the HGT and 6MWT results explained 39% of the variation in trail B reaction times: HGT accounted for 18% and 6MWT for 21%. Better scores on the 6MWT and HGT-but not on the 8FUGT and CST-correlated with enhanced executive function in cognitively healthy community-dwelling older females. The results of this study underscore the importance of specific physical assessments, like the 6MWT and HGT, as potential indicators of executive function, offering targeted strategies for maintaining cognitive health in aging females.

7.
Am J Hypertens ; 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38703068

RESUMO

BACKGROUND: More habitual time spent engaging in prolonged sedentary behaviours increases the risk of developing hypertension. Beat-by-beat systolic (SBPV) and diastolic blood pressure variability (DBPV) are more pronounced in persons with hypertension and may be an early manifestation of blood pressure dysregulation. We tested the hypothesis that a single bout of prolonged sitting augments very short-term SBPV and DBPV. The secondary aim was to explore sex differences in prolonged sitting-induced increases in SBPV and DBPV. METHODS: Thirty-three adults (22.9±1.9 years; 17 females) completed a single, 3-hr bout of prolonged sitting with beat-by-beat arterial pressure determined at baseline, 1.5-hr, and 3-hr via finger photoplethysmography. RESULTS: There were no sex differences observed for baseline brachial SBP (males: 122±10 mmHg; females: 111±9 mmHg), SBPV (males: 1.87±0.63 mmHg; females: 1.51±0.38 mmHg), DBP (males: 68±6 mmHg; females: 66±8 mmHg), or DBPV (males: 1.40±0.41 mmHg; females: 1.27±0.32 mmHg) (all, p>0.41). In the pooled sample, baseline SBPV (1.68±0.54 mmHg) remained unchanged after 1.5-hr (1.80±0.60 mmHg; p=0.59), but increased after 3.0-hr (1.84±0.52 mmHg; p=0.01). This post-sitting increase was driven by males (p=0.009), with no difference observed in females (p=1.00). Similarly, baseline DBPV (1.33±0.36 mmHg) was similar after 1.5-hr (1.42±0.41 mmHg; p=0.72) but was increased at 3-hr (1.50±0.34 mmHg; p=0.02). However, no sex differences in DBPV (all, p>0.07) were observed across the time points. CONCLUSIONS: In young, normotensive adults, a single bout of prolonged sitting augmented beat-by-beat blood pressure variability, which may provide a link between uninterrupted sitting and the development of blood pressure dysregulation.

8.
J Clin Ultrasound ; 52(6): 763-772, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38660883

RESUMO

PURPOSE: Contrast-enhanced duplex ultrasound (CEUS) might be a useful tool to diagnosing renal artery stenosis (RAS). We amalgamated and reviewed the evidence assessing the diagnostic accuracy of CEUS on detecting RAS compared to angiography. METHODS: This preregistered systematic review included studies that compared the presence of RAS via CEUS with angiography. Sources were searched in November 2022 and included Scopus, EMBASE, MEDLINE, CINAHL, and Academic Search Premier (n = 1717). The Quality Assessment of Diagnostic Studies 2 tool assessed study quality. Results are presented narratively. RESULTS: The studies included (n = 11) had a total of 447 unique participants (193 females) and average age of 56 ± 9 years. Five of eleven studies investigated CEUS using SonoVue contrast agent and reported an average accuracy (91% ± 2%), sensitivity (91% ± 3%), specificity (90% ± 5%), negative predictive value (86% ± 6%), and positive predictive value (94% ± 1%) with all values >80%. The accuracy of CEUS using other types of contrast agent (n = 6), including Levovsit (n = 3/6), Definity (n = 1/6), perfienapent emulsion (n = 1/6), and perfluorocarbon-exposed sonicated dextrose albumin (n = 1/6) was mixed. These studies detected an average accuracy of 91 ± 11% (n = 2/3% > 80%), sensitivity of 98% ± 4%, (n = 3/3% > 80%), and specificity of 86% ± 10% (n = 2/3% > 80%). Included studies had generally low risk of bias and applicability concerns except for unclear flow and timing (n = 7/11) and applicability of patient selection (n = 4/11). CONCLUSION: Despite being limited by the heterogeneity of included studies, our review indicates a high overall diagnostic accuracy for CEUS to detect RAS compared to angiography, with the largest evidence-base for SonoVue contrast. Radiologists and hospital decision makers should consider CEUS as an acceptable alternative to angiography.


Assuntos
Meios de Contraste , Obstrução da Artéria Renal , Ultrassonografia Doppler Dupla , Humanos , Obstrução da Artéria Renal/diagnóstico por imagem , Ultrassonografia Doppler Dupla/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Artéria Renal/diagnóstico por imagem , Aumento da Imagem/métodos
9.
Sci Rep ; 14(1): 8003, 2024 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-38580840

RESUMO

Advancing age is associated with declines in cognitive function. Although physical activity is thought to protect against this decline, it is unclear how a short-term uptake in daily steps or a decline in day-to-day step variability may contribute to cognition among older adults. We tested associations between changes in step counts, day-to-day step variability and executive cognitive functions among older adults taking part in a physical activity intervention. Thirty-seven older adults (33 females; 71.4 ± 6.3 years) completed a 10-week personalized physical activity intervention. Participants wore a Fitbit to measure daily step counts throughout the study. They also completed a computerized Stroop task before and after the intervention. Average step counts and step count variability via average-real-variability (ARV) were determined. Compared to pre-intervention, step counts increased (p < 0.001) and step variability decreased post-intervention (p = 0.04). Models describing the changes in step counts and ARV over the 10-weeks were cubic (both, p < 0.04). Reaction times during the simple (p = 0.002) and switching (p = 0.04) conditions were faster post-intervention. Change in step variability was positively associated with the change in reaction time for the switching condition (ß = 0.029, p = 0.002). On average, a reduction in day-to-day step variability was associated with improvements in cognitive flexibility.


Assuntos
Cognição , Exercício Físico , Feminino , Humanos , Idoso , Teste de Stroop
10.
Vasc Med ; : 1358863X241238702, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594895

RESUMO

INTRODUCTION: Single bouts of prolonged bent-legged sitting attenuate popliteal endothelial-dependent vasodilation (as assessed via flow-mediated dilation [FMD]), which is partially attributed to arterial 'kinking'. However, the impact of knee-flexion angle on sitting-induced popliteal FMD is unknown. The objective of this study was to perform separate laboratory and free-living studies to test the hypotheses that: (1) popliteal FMD impairments would be graded between knee flexions at 90° (bent-legged sitting) > 45° > 0° (straight-legged sitting) following a 3-hour bout of sitting; and (2) more habitual time spent bent-legged sitting (< 45°) would be associated with lower FMD. METHODS: The laboratory study included eight young, healthy adults (24 ± 2 years; four women) who underwent two sitting bouts over 2 days with one leg positioned at a knee-flexion angle of 0° or 90° and the opposite leg at 45° knee flexion. Popliteal FMD was assessed at pre- and postsitting timepoints. RESULTS: Sitting-induced reductions in FMD were similar between all knee-flexion angles (all, p > 0.674). The free-living study included 35 young, healthy adults (23 ± 3 years; 16 women) who wore three activPAL monitors (torso, thigh, shin) to determine detailed sedentary postures. Time spent sedentary (624 ± 127 min/day), straight-legged sitting (112 ± 98 min/day), and bent-legged sitting (442 ± 106 min/day) were not related to relative FMD (5.3 ± 1.8%; all, p > 0.240). CONCLUSION: These findings suggest that knee-flexion angle-mediated arterial 'kinking' during sitting is not a major contributor toward sitting-induced popliteal endothelial-dependent vasodilatory dysfunction.

11.
J Appl Physiol (1985) ; 136(5): 1238-1244, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38545662

RESUMO

The metabolic cost of walking (MCOW), or oxygen uptake normalized to distance, provides information on the energy expended during movement. There are conflicting reports as to whether sex differences in MCOW exist, with scarce evidence investigating factors that explain potential sex differences. This study 1) tested the hypothesis that females exhibit a higher MCOW than males, 2) determined whether normalizing to stepping cadence ameliorates the hypothesized sex difference, and 3) explored whether more habitual step counts and time in intensity-related physical activity, and less sedentary time were associated with a decreased MCOW. Seventy-six participants (42 females, 24 ± 5 yr) completed a five-stage, graded treadmill protocol with speeds increasing from 0.89 to 1.79 m/s (6-min walking stage followed by 4-min passive rest). Steady-state oxygen uptake (via indirect calorimetry) and stepping cadence (via manual counts) were determined. Gross and net MCOW, normalized to distance traveled (km) and step-cadence (1,000 steps) were calculated for each stage. Thirty-nine participants (23 females) wore an activPAL on their thigh for 6.9 ± 0.4 days. Normalized to distance, females had greater gross MCOW (J/kg/km) at all speeds (P < 0.014). Normalized to stepping frequency, females exhibited greater gross and net MCOW at 1.12 and 1.79 m/s (J/kg/1,000 steps; P < 0.01) but not at any other speeds (P < 0.075). Stature was negatively associated with free-living cadence (r = -0.347, P = 0.030). Females expend more energy/kilometer traveled than males, but normalizing to stepping cadence attenuated these differences. Such observations provide an explanation for prior work documenting higher MCOW among females and highlight the importance of stepping cadence when assessing the MCOW.NEW & NOTEWORTHY Whether there are sex differences in the metabolic cost of walking (MCOW) and the factors that may contribute to these are unclear. We demonstrate that females exhibit a larger net MCOW than males. These differences were largely attenuated when normalized to stepping cadence. Free-living activity was not associated with MCOW. We demonstrate that stepping cadence, but not free-living activity, partially explains the higher MCOW in females than males.


Assuntos
Metabolismo Energético , Consumo de Oxigênio , Caminhada , Humanos , Feminino , Masculino , Metabolismo Energético/fisiologia , Adulto , Caminhada/fisiologia , Consumo de Oxigênio/fisiologia , Adulto Jovem , Teste de Esforço/métodos , Caracteres Sexuais , Fatores Sexuais
12.
Drug Discov Ther ; 18(1): 16-23, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38382931

RESUMO

The eight flavonoids, apigenin, chrysin, hesperidin, kaempferol, myricetin, quercetin, rutin and luteolin were tested for the inhibition of human parainfluenza virus type 2 (hPIV-2) replication. Three flavonoids out of the eight, kaempferol, quercetin and luteolin inhibited hPIV-2 replication. Kaempferol reduced the virus release (below 1/10,000), partly inhibited genome and mRNA syntheses, but protein synthesis was observed. It partly inhibited virus entry into the cells and virus spreading, and also partly disrupted microtubules and actin microfilaments, indicating that the virus release inhibition was partly caused by the disruption of cytoskeleton. Quercetine reduced the virus release (below 1/10,000), partly inhibited genome, mRNA and protein syntheses. It partly inhibited virus entry and spreading, and also partly destroyed microtubules and microfilaments. Luteolin reduced the virus release (below 1/100,000), largely inhibited genome, mRNA and protein syntheses. It inhibited virus entry and spreading. It disrupted microtubules and microfilaments. These results indicated that luteolin has the most inhibitory effect on hPIV-2 relication. In conclusion, the three flavonoids inhibited virus replication by the inhibition of genome, mRNA and protein syntheses, and in addition to those, by the disruption of cytoskeleton in vitro.


Assuntos
Quempferóis , Quercetina , Humanos , Quercetina/farmacologia , Quempferóis/farmacologia , Vírus da Parainfluenza 2 Humana , Luteolina/farmacologia , Flavonoides , RNA Mensageiro/metabolismo , Replicação Viral
13.
Am J Physiol Heart Circ Physiol ; 326(3): H612-H622, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38214907

RESUMO

Discharge of postganglionic muscle sympathetic nerve activity (MSNA) is related poorly to blood pressure (BP) in adults. Whether neural measurements beyond the prevailing level of MSNA can account for interindividual differences in BP remains unclear. The current study sought to evaluate the relative contributions of sympathetic-BP transduction and sympathetic baroreflex gain on resting BP in young adults. Data were analyzed from 191 (77 females) young adults (18-39 years) who underwent continuous measurement of beat-to-beat BP (finger photoplethysmography), heart rate (electrocardiography), and fibular nerve MSNA (microneurography). Linear regression analyses were computed to determine associations between sympathetic-BP transduction (signal-averaging) or sympathetic baroreflex gain (threshold technique) and resting BP, before and after controlling for age, body mass index, and MSNA burst frequency. K-mean clustering was used to explore sympathetic phenotypes of BP control and consequential influence on resting BP. Sympathetic-BP transduction was unrelated to BP in males or females (both R2 < 0.01; P > 0.67). Sympathetic baroreflex gain was positively associated with BP in males (R2 = 0.09, P < 0.01), but not in females (R2 < 0.01; P = 0.80), before and after controlling for age, body mass index, and MSNA burst frequency. K-means clustering identified a subset of participants with average resting MSNA, yet lower sympathetic-BP transduction and lower sympathetic baroreflex gain. This distinct subgroup presented with elevated BP in males (P < 0.02), but not in females (P = 0.10). Sympathetic-BP transduction is unrelated to resting BP, while the association between sympathetic baroreflex gain and resting BP in males reveals important sex differences in the sympathetic determination of resting BP.NEW & NOTEWORTHY In a sample of 191 normotensive young adults, we confirm that resting muscle sympathetic nerve activity is a poor predictor of resting blood pressure and now demonstrate that sympathetic baroreflex gain is associated with resting blood pressure in males but not females. In contrast, signal-averaged measures of sympathetic-blood pressure transduction are unrelated to resting blood pressure. These findings highlight sex differences in the neural regulation of blood pressure.


Assuntos
Barorreflexo , Hipertensão , Adulto Jovem , Humanos , Masculino , Feminino , Pressão Sanguínea/fisiologia , Barorreflexo/fisiologia , Frequência Cardíaca/fisiologia , Sistema Nervoso Simpático , Músculo Esquelético/inervação
14.
Am J Physiol Heart Circ Physiol ; 326(1): H238-H255, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37999647

RESUMO

In cardiovascular research, sex and gender have not typically been considered in research design and reporting until recently. This has resulted in clinical research findings from which not only all women, but also gender-diverse individuals have been excluded. The resulting dearth of data has led to a lack of sex- and gender-specific clinical guidelines and raises serious questions about evidence-based care. Basic research has also excluded considerations of sex. Including sex and/or gender as research variables not only has the potential to improve the health of society overall now, but it also provides a foundation of knowledge on which to build future advances. The goal of this guidelines article is to provide advice on best practices to include sex and gender considerations in study design, as well as data collection, analysis, and interpretation to optimally establish rigor and reproducibility needed to inform clinical decision-making and improve outcomes. In cardiovascular physiology, incorporating sex and gender is a necessary component when optimally designing and executing research plans. The guidelines serve as the first guidance on how to include sex and gender in cardiovascular research. We provide here a beginning path toward achieving this goal and improve the ability of the research community to interpret results through a sex and gender lens to enable comparison across studies and laboratories, resulting in better health for all.


Assuntos
Pesquisa Biomédica , Cardiologia , Caracteres Sexuais , Feminino , Humanos , Masculino , Sistema Cardiovascular
15.
Geroscience ; 46(1): 597-607, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37880489

RESUMO

Frailty is characterized by an increased vulnerability to adverse health events. Executive function impairment is an early sign of progression towards cognitive impairments. Whether frailty is associated with executive function and the associated mechanisms are unclear. We test the hypothesis that higher frailty is associated with worse executive function (Trail Making Test) and if aerobic fitness, prefrontal cortex oxygenation (ΔO2Hb), or middle-cerebral artery velocity (MCAv) impact this association. Forty-one (38 females) cognitively health older adults (70.1 ± 6.3 years) completed a Trail task and 6-min walk test. Prefrontal cortex oxygenation was measured during the Trail task (via functional near-infrared spectroscopy) and MCAv in a sub-sample (n=26, via transcranial Doppler). A 35-item frailty index was used. Frailty was independently, non-linearly related to trail B performance (Frailty2: ß=1927 [95% CI: 321-3533], p = 0.02), with the model explaining 22% of the variance of trail B time (p = 0.02). Aerobic fitness was an independent predictor of trail B (ß=-0.05 [95% CI: -0.10-0.004], p = 0.04), but age and ΔO2Hb were not (both, p > 0.78). Frailty was positively associated with the difference between trails B and A (ß=105 [95% CI: 24-186], p = 0.01). Frailty was also associated with a higher peak MCAv (ρ = 0.40, p = 0.04), but lower ΔO2Hb-peakMCAv ratio (ρ = -0.44, p = 0.02). Higher frailty levels are associated to worse Trail times after controlling for age, aerobic fitness, and prefrontal oxygenation. High frailty level may disproportionately predispose older adults to challenges performing executive function tasks that may manifest early as a compensatory higher MCAv despite worse executive function, and indicate a greater risk of progressing to cognitive impairment.


Assuntos
Função Executiva , Fragilidade , Feminino , Humanos , Idoso , Estudos Transversais , Teste de Sequência Alfanumérica , Córtex Pré-Frontal
16.
Can Geriatr J ; 26(4): 524-529, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38045878

RESUMO

Functional independence is dictated by the ability to perform basic activities of daily living (ADLs). Although hospitalization is associated with impairments in function, we know less about patients' functional trajectory following hospitalization. We examined patients' ability to do basic ADLs across pre-admission, admission, and follow-up (discharge or two-weeks post-admission) and determined which factors predicted changes in ADLs at follow-up. A secondary analysis of a small prospective cohort study of older patients (n=83, 50 females, 81 ± 8 years) from the Emergency Department and a Geriatric Unit were included. ADL scores (dressing, walking, bathing, eating, in and out of bed, and using the toilet) and frailty level (via the Clinical Frailty Scale) were measured. Comparing follow-up to pre-admission, patients reported worse ADL scores for dressing (36% of patients), walking (31%), bathing (34%), eating (25%), in and out of bed (37%), and using the toilet (35%). Most patients (59%) had more difficulty with 1+ ADL at follow-up versus pre-admission, with one-fourth of patients having greater difficulty with 3+ ADLs. Older age and higher frailty level were associated with (all, p < .04) worse functional scores for eating, getting in and out of bed, and using the toilet (frailty only) at follow-up versus pre-admission. Here, most inpatients experienced worse difficulty performing multiple basic ADLs after hospital admission, potentially predisposing them for re-hospitalization and functional dependence. Older and frailer patients generally were less likely to recover to pre-admission levels. Hospitalization challenges patients' ability to perform ADLs in the short-term, post-discharge. Strategies to improve patients' functional trajectory are needed.

17.
Eur J Appl Physiol ; 123(12): 2687-2697, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37804365

RESUMO

Endothelial function is commonly determined via the ultrasound-based flow-mediated dilation (FMD) technique which assesses arterial dilation in response to a hyperemia response following distal cuff occlusion. However, the low-flow-mediated constriction (L-FMC) response during cuff-induced ischemia is often overlooked. L-FMC provides unique information regarding endothelial function, but vascular researchers may be unclear on what this metric adds. Therefore, the objective of this review was to examine the mechanistic determinants and participant-level factors of L-FMC. Existing mechanistic studies have demonstrated that vasoreactivity to low flow may be mediated via non-nitric oxide vasodilators (i.e., endothelial hyperpolarizing factors and/or prostaglandins), inflammatory markers, and enhancement of vasoconstriction via endothelin-1. In general, participant-level factors such as aging and presence of cardiovascular conditions generally are associated with attenuated L-FMC responses. However, the influence of sex on L-FMC is unclear with divergent results between L-FMC in upper versus lower limb vessels. The ability of aerobic exercise to augment L-FMC (i.e., make more negative) is well supported, but there is a major gap in the literature concerning the mechanistic underpinnings of this observation. This review summarizes that while larger L-FMC responses are generally healthy, the impact of interventions to augment/attenuate L-FMC has not included mechanistic measures that would provide insight into non-nitric oxide-based endothelial function. Clarifications to terminology and areas of further inquiry as it relates to the specific pharmacological, individual-level factors, and lifestyle behaviors that impact L-FMC are highlighted. A greater integration of mechanistic work alongside applied lifestyle interventions is required to better understand endothelial cell function to reductions in local blood flow.


Assuntos
Artéria Braquial , Endotélio Vascular , Humanos , Artéria Braquial/fisiologia , Constrição , Endotélio Vascular/fisiologia , Ultrassonografia , Óxidos , Vasodilatação/fisiologia , Fluxo Sanguíneo Regional/fisiologia
18.
J Can Chiropr Assoc ; 67(2): 105-116, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37840580

RESUMO

Background: Physical activity and exercise (PAE) counselling and exercise prescriptions increase patient physical activity. However, the perceptions/practices of chiropractors are poorly understood. Methods: We surveyed the practices among chiropractors working in Canada (n=50) and Internationally (n=37). Chiropractors completed self-reflection questionnaires regarding their current practices and perceptions towards providing PAE counselling to patients. Chiropractor responses were obtained via Canadian provincial survey and educational workshops. Results: Chiropractor respondents included PAE content and exercise prescriptions in most patient appointments (67±27% and 59±35%, respectively), but the largest barriers (2.5/4.0) and least confidence were in their patients to follow through (52±21%). Canadian respondents reported higher knowledge (~0.4/4.0 higher), greater self-confidence (10-20% higher), and provided more PAE recommendations (8%) and prescriptions (16%) than International respondents. Chiropractor respondents were least comfortable advising patients with cancer. Conclusion: Chiropractor respondents may serve as health promotors to address patient inactivity, and the challenges identified should be addressed through educational training.


Contexte: Les conseils en matière d'activité physique et d'exercice (APE) et les prescriptions d'exercices augmentent l'activité physique des patients. Cependant, les perceptions et les pratiques des chiropraticiens sont mal comprises. Méthodologie: Nous avons enquêté sur les pratiques des chiropraticiens travaillant au Canada (n=50) et à l'étranger (n=37). Les chiropraticiens ont rempli des questionnaires d'auto-réflexion sur leurs pratiques actuelles et leurs perceptions quant à l'offre de conseils aux patients en matière d'APE. Les réponses des chiropraticiens ont été obtenues au moyen d'une enquête provinciale canadienne et des ateliers éducatifs. Résultats: Les chiropraticiens interrogés ont inclus le contenu d'APE et les prescriptions d'exercices dans la plupart des rendez-vous avec les patients (67±27 % et 59±35 %, respectivement), mais les obstacles les plus importants (2,5/4,0) et la confiance la plus faible étaient à propos du fait que leurs patients allaient suivre les conseils (52±21 %). Les répondants canadiens ont fait état d'une meilleure connaissance (~0,4/4,0 de plus), d'une plus grande confiance en soi (10­20 % de plus) et ont fourni plus de recommandations (8 %) et de prescriptions (16 %) en matière d'APE que les répondants internationaux. Les chiropraticiens interrogés se sont montrés moins à l'aise pour conseiller les patients atteints de cancer. Conclusion: Les chiropraticiens interrogés peuvent servir de promoteurs de la santé pour lutter contre l'inactivité des patients, et les difficultés relevées devraient être abordées dans le cadre d'une formation.

19.
Am J Physiol Heart Circ Physiol ; 325(5): H933-H948, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37594481

RESUMO

Elevated pulse wave velocity (PWV) determined arterial stiffness is a prominent marker of cardiovascular disease (CVD) risk. Exercise training delays the progression of CVD, but existing reviews on the impact of training on PWV are conflicting. We synthesized the evidence on the effects of exercise training interventions on PWV. We searched Scopus, EMBASE, PubMed, CINAHL, and Academic Search Premier databases for systematic reviews including PWV, and examined the effects of exercise training on PWV. We screened 842 citations that resulted in 44 systematic reviews, including 22 meta-analyses [unique participants, n = 6,719 (3,390 females)]. Studies were conducted in general adults with/without disease(s) (n = 19, 8 meta-analyses), kidney disease (n = 9, 6 meta-analyses), increased CVD risk or CVD (n = 7, 5 meta-analyses), type 2 diabetes mellitus (n = 3, 2 meta-analyses), and other conditions (n = 6, 2 meta-analyses). In general adults, PWV was reduced by aerobic exercise (ß, -0.75 to -0.52 m/s) and low-to-moderate intensity resistance exercise training (ß, -0.34 m/s). Exercise training was beneficial for patients with kidney disease (ß, -1.13 to -0.56 m/s). Aerobic exercise improved PWV in adults with CVD or high CVD risk (ß, -0.70 to -0.42 m/s). Combined aerobic and resistance exercise training decreased carotid-femoral (CF) PWV in patients with CVD (ß, -1.15 m/s) and decreased brachial-ankle (BA) PWV in postmenopausal females (ß, -1.18 m/s). Neither aerobic nor combined training improved PWV in individuals with type 2 diabetes. The potential physiological mechanisms involved are discussed. Overall, the included systematic reviews and meta-analyses documented that exercise training was an effective strategy to improve PWV, but the optimal type of training varied between populations.

20.
Appl Physiol Nutr Metab ; 48(12): 1019-1022, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37586105

RESUMO

TAKE HOME MESSAGE: Our case study indicated that a bifurcated brachial artery exhibited worse vasodilatory responses relative to an intact contralateral artery.


Assuntos
Artéria Braquial , Vasodilatação , Vasodilatação/fisiologia , Artéria Braquial/fisiologia , Endotélio Vascular/fisiologia , Extremidade Superior , Fluxo Sanguíneo Regional
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