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1.
Res Sq ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38946990

RESUMO

Background: Sedentary behavior (SB) is detrimental to cardiometabolic disease (CMD) risk, which can begin in young adulthood. To devise effective SB-CMD interventions in young adults, it is important to understand which context-specific sedentary behaviors (CS-SB) are most detrimental for CMD risk, the lifestyle behaviors that co-exist with CS-SBs, and the socioecological predictors of CS-SB. Methods: This longitudinal observational study will recruit 500 college-aged (18-24 years) individuals. Two laboratory visits will occur, spaced 12 months apart, where a composite CMD risk score (e.g., arterial stiffness, metabolic and inflammatory biomarkers, heart rate variability, and body composition) will be calculated, and questionnaires to measure lifestyle behaviors and different levels of the socioecological model will be administered. After each visit, total SB (activPAL) and CS-SB (television, transportation, academic/ occupational, leisure computer, "other"; ecological momentary assessment) will be measured across seven days. Discussion: It is hypothesized that certain CS-SB will show stronger associations with CMD risk, compared to T-SB, even after accounting for coexisting lifestyle behaviors. It is expected that a range of intra-individual, inter-individual, and physical environment socioecological factors will predict CS-SB. The findings from this study will support the development of an evidence-based, multi-level intervention to target SB reduction and mitigate CMD risk in CBYA.

2.
Eur J Appl Physiol ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801445

RESUMO

Independently, both prolonged uninterrupted sitting and the onset of menopause negatively impact markers of cardiovascular risk. Whether their combination augment these responses additively remains unknown. This study assessed whether prolonged uninterrupted sitting causes greater central and peripheral cardiovascular dysfunction in post-menopausal women compared to pre-menopausal women. To address this, 23 healthy women (13 pre-menopausal [43.77 ± 4.30 years] and 10 post-menopausal [57.20 ± 8.55 years]) sat uninterrupted for 2-h. Carotid-femoral pulse wave velocity (cf-PWV), pulse wave analysis (PWA), lower limb venous pooling (HHb), and calf circumference were assessed pre-and post-sitting using general linear mixed models, with age as a covariate. Changes in MAP over time (both between and within groups) was assessed using a two-way repeated-measures-ANOVA. There were no significant interactions for any outcome measures. However, for cf-PWV, there was a significant main effect of group (Δ = 0.854 ± 0.354 m s-1; p = 0.026, ηp2 = 0.707). For PWA, only heart rate (HR) and pressure forwards (Pf) showed significant main effects 13 of time [Δ = 6 ± 1 bts-min-1, p < 0.001, ηp2 = 0.861] and group [Δ = 3.893 ± 1.450 mmHg, p = 0.016, ηp2 = 0.271], respectively. Both HHb (Δ = 2.737 ± 0.952, p = 0.009, ηp2 = 0.742) and calf circumference (Δ = 0.812 ± 0.128 cm, p < 0.001, ηp2 = 0.863) significantly increased over time. Whilst post-menopausal women demonstrated greater overall arterial stiffness (increased cf-PWV at baseline), there was no difference in cardiovascular response (central or peripheral) to 2-h of prolonged sitting between the pre- and post-menopausal women.

3.
J Appl Physiol (1985) ; 136(5): 1087-1096, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38482575

RESUMO

Prolonged uninterrupted sitting of >3 h has been shown to acutely cause central and peripheral cardiovascular dysfunction. However, individuals rarely sit uninterrupted for >2 h, and the cardiovascular response to this time is currently unknown. In addition, while increased cardiorespiratory fitness (CRF) and habitual physical activity (HPA) are independently associated with improvements in central and peripheral cardiovascular function, it remains unclear whether they influence the response to uninterrupted sitting. This study sought to 1) determine whether 2 h of uninterrupted sitting acutely impairs carotid-femoral pulse wave velocity (cfPWV), femoral ankle PWV (faPWV), and central and peripheral blood pressure and 2) investigate the associations between CRF and HPA versus PWV changes during uninterrupted sitting. Following 2 h of uninterrupted sitting, faPWV significantly increased [mean difference (MD) = 0.26 m·s-1, standard error (SE) = 0.10, P = 0.013] as did diastolic blood pressure (MD = 2.83 mmHg, SE = 1.08, P = 0.014), however, cfPWV did not significantly change. Although our study shows 2 h of uninterrupted sitting significantly impairs faPWV, neither CRF (r = 0.105, P = 0.595) nor HPA (r = -0.228, P = 0.253) was associated with the increases.NEW & NOTEWORTHY We demonstrate that neither cardiorespiratory fitness nor habitual physical activity influence central and peripheral cardiovascular responses to a 2-h bout of uninterrupted sitting in healthy young adults.


Assuntos
Pressão Sanguínea , Aptidão Cardiorrespiratória , Exercício Físico , Análise de Onda de Pulso , Postura Sentada , Humanos , Aptidão Cardiorrespiratória/fisiologia , Masculino , Exercício Físico/fisiologia , Feminino , Pressão Sanguínea/fisiologia , Adulto , Análise de Onda de Pulso/métodos , Adulto Jovem , Comportamento Sedentário , Velocidade da Onda de Pulso Carótido-Femoral/métodos , Rigidez Vascular/fisiologia , Sistema Cardiovascular/fisiopatologia
4.
Eur J Appl Physiol ; 124(7): 1959-1967, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38280015

RESUMO

PURPOSE: Prolonged sitting acutely increases arterial stiffness, with interruption strategies only providing limited success in offsetting these rises. Acute aerobic exercise is a potent stimulus to decrease arterial stiffness. However, limited information exists on the effectiveness of acute exercise to maintain arterial stiffness when performed prior to prolonged sitting, particularly within physically active individuals. METHODS: Using a randomized crossover design, 22 young, active individuals (50% female) performed two conditions 30 min of walking at 55-65% of heart rate reserve (EX) and 30 min of standing (STAND) followed by 2.5-h of sitting. Brachial-femoral (bfPWV) and femoral-ankle pulse wave velocity (faPWV) were assessed at Baseline, post-exercise and pre-sitting (Pre), and post-sitting (Post) as estimates of central and peripheral arterial stiffness, respectively. RESULTS: For bfPWV, no interaction, condition, or time effects were observed. For faPWV, an interaction was present (p < 0.001); compared to Baseline, there was a 6.1% decrease for EX (- 0.4 m/s, p < 0.001) and a 4.6% increase for STAND (0.3 m/s, p = 0.016) for STAND such that there was an 11.3% difference between conditions at Pre (0.7 m/s, p < 0.001). From Pre to Post, EX then increased by 11.7% (0.9 m/s p < 0.001) while STAND remained unchanged, resulting in no difference between conditions (0.1 m/s, p = 0.569). CONCLUSIONS: While aerobic exercise resulted in a significant decrease in faPWV prior to sitting, the prior exercise bout did not confer a protective effect against the deleterious effects of uninterrupted sitting. Future work should investigate the combined effect of prior exercise and sitting interruption strategies on markers of arterial stiffness.


Assuntos
Exercício Físico , Postura Sentada , Rigidez Vascular , Humanos , Rigidez Vascular/fisiologia , Feminino , Masculino , Exercício Físico/fisiologia , Adulto , Análise de Onda de Pulso , Estudos Cross-Over , Adulto Jovem
5.
Sports Med ; 54(1): 169-183, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37682412

RESUMO

BACKGROUND: A previous meta-analysis reported that: (i) an acute bout of prolonged uninterrupted sitting induces a significant increase in peripheral blood pressure (BP) and (ii) the increase in BP can be offset by interrupting the sitting bout with light aerobic activities such as walking. However, the temporal association between prolonged uninterrupted sitting and BP was not determined. A better understanding of temporality, for example, how long it takes BP to increase, will assist in prescribing sitting interruption strategies. OBJECTIVES: We aimed to determine: (1) the temporal association between the duration of uninterrupted sitting and BP and (2) whether regular sitting interruptions moderate the association between uninterrupted sitting and BP. DATA SOURCES: Electronic databases (PubMed, Web of Science, SPORTDiscus) were searched from inception to July 2022. Reference lists of eligible studies and relevant reviews were also screened. STUDY SELECTION: Inclusion criteria for objective (1) were: (i) participants aged ≥ 18 years; (ii) a prolonged sitting bout ≥ 1 h; and (iii) peripheral BP measurements (systolic BP, diastolic BP, and/or mean arterial pressure) at more than two timepoints during the sitting bout. Additional criteria for objective (2) were: (i) the sitting interruption strategy was implemented during the sitting bout (i.e., not prior to engaging in sitting) and (ii) the study included a control (uninterrupted sitting) condition or group. APPRAISAL AND SYNTHESIS METHODS: There were 1555 articles identified, of which 33 met inclusion criteria for objective (1). Of those articles, 20 met inclusion criteria for objective (2). To investigate the effect of sitting duration on the BP response, unstandardized b coefficients (mmHg/h) and 95% confidence intervals (CIs) were calculated using a three-level mixed-effect meta-regression. RESULTS: Increased sitting duration was positively associated with systolic BP (b = 0.42 mmHg/h, 95% CI 0.18-0.60), diastolic BP (b = 0.24 mmHg/h, 95% CI 0.06-0.42), and mean arterial pressure (b = 0.66 mmHg/h, 95% CI 0.36-0.90). In trials where sitting was interrupted, there was a significant decrease in systolic BP (b = - 0.24 mmHg/h, 95% CI - 0.42 to - 0.06) and diastolic BP (b = - 0.24 mmHg/h, 95% CI - 0.42 to - 0.12), and a non-significant change in mean arterial pressure (p = 0.69). CONCLUSIONS: Increased uninterrupted sitting duration results in greater increases in BP; however, regularly interrupting sitting may offset negative effects.


Assuntos
Pressão Sanguínea , Exercício Físico , Humanos , Pressão Arterial , Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Hipertensão , Caminhada/fisiologia
6.
Clin Transl Gastroenterol ; 15(1): e00656, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37870521

RESUMO

INTRODUCTION: Consensus is lacking regarding the number of eosinophils (eos) required for the diagnosis of eosinophilic gastritis (EoG) and eosinophilic duodenitis (EoD). In addition, thresholds that require multiple high-power fields (HPFs) may not be practical for clinical use, resulting in delayed or missed diagnoses. This pooled analysis of 4 prospective studies assessed thresholds for multiple and single HPFs used to diagnose EoG and EoD. METHODS: Studies included the phase 2 ENIGMA1, the phase 3 ENIGMA2, an EoG/EoD prevalence study and a healthy volunteer study. Eos were quantified in the epithelium and lamina propria for controls and symptomatic participants. Symptomatic participants were further divided by histologic diagnosis of EoG/EoD. Peak eos counts were assessed, and the area under the receiver operating characteristic curve was analyzed to identify eos cutoffs for detection of EoG/EoD using the Youden index and sensitivity and specificity equality approaches. RESULTS: Based on the highest specificity analysis in 740 patients, the optimal eos threshold was determined to be 20 eos/HPF in 5 gastric HPFs for EoG (71% sensitivity and 94% specificity) and 33 eos/HPF in 3 duodenal HPFs for EoD (49% sensitivity and 100% specificity). For single-field analysis, the optimal eos thresholds were 33 eos/HPF (EoG) and 37 eos/HPF (EoD), both corresponding to 93% sensitivity and 93% specificity. DISCUSSION: Highly specific single gastric and duodenal HPF thresholds may have more clinical applicability than thresholds requiring multiple HPFs and could better facilitate development of practical histopathologic guidelines to aid pathologists and clinicians in the detection and diagnosis of EoG and/or EoD.


Assuntos
Duodenite , Enterite , Eosinofilia , Gastrite , Humanos , Eosinófilos/patologia , Estudos Prospectivos , Duodenite/diagnóstico , Duodenite/patologia , Eosinofilia/diagnóstico
7.
Front Res Metr Anal ; 8: 1205874, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37876577

RESUMO

The goal of this paper is to introduce Sciducio, a practical framework for guiding the development and leadership of an academic research environment. The principal audience for this framework is new academics, that is individuals beginning a tenure-track position in the U.S or a lecturing position elsewhere in the world. However, we also believe this framework will be of use to established academics searching for structure, academics moving to a new institution, and can serve as a training tool for doctoral and postdoctoral mentees. We briefly describe the theory supporting Sciducio, outline the framework and its individual components (blocks), then provide suggested instructions for use. We provide suggested instructions (i.e., descriptive rather than prescriptive), because there is no one-size-fits-all approach for ensuring success. Sciducio incorporates three domains (Plan, Manage, and Deliver), encompasses eight blocks, and is intended to fit on one-sheet of paper or one screen. The Plan domain includes the blocks: value, strategy, and leadership. The Manage domain includes the blocks: activities, key resources, and finances. The Deliver domain includes the blocks: solution and channels. Considering each of the framework blocks is complex, we cannot provide full justice to each component. This paper serves as a general overview and subsequent papers will be more topic specific. Additionally, we encourage others to contribute to and advance this framework.

8.
Sports Med Open ; 9(1): 84, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37697072

RESUMO

BACKGROUND: Inorganic nitrate (NO3-) supplementation is purported to benefit short-term exercise performance, but it is unclear whether NO3- improves longer-term exercise training responses (such as improvements in VO2peak or time to exhaustion (TTE)) versus exercise training alone. The purpose of this systematic review and meta-analysis was to determine the effects of NO3- supplementation combined with exercise training on VO2peak and TTE, and to identify potential factors that may impact outcomes. METHODS: Electronic databases (PubMed, Medscape, and Web of Science) were searched for articles published through June 2022 with article inclusion determined a priori as: (1) randomized placebo-controlled trials, (2) exercise training lasted at least three weeks, (3) treatment groups received identical exercise training, (4) treatment groups had matched VO2peak at baseline. Study quality was assessed using the Cochrane Risk-of-Bias 2 tool. Standardized mean difference (SMD) with 95% confidence intervals (CI) were calculated using restricted maximum likelihood estimation between pre- and post-training differences in outcomes. Moderator subgroup and meta-regression analyses were completed to determine whether the overall effect was influenced by age, sex, NO3- dosage, baseline VO2peak, health status, NO3- administration route, and training conditions. RESULTS: Nine studies consisting of eleven trials were included: n = 228 (72 females); age = 37.7 ± 21 years; VO2peak: 40 ± 18 ml/kg/min. NO3- supplementation did not enhance exercise training with respect to VO2peak (SMD: 0.18; 95% CI: -0.09, 0.44; p = 0.19) or TTE (SMD: 0.08; 95% CI: - 0.21, 0.37; p = 0.58). No significant moderators were revealed on either outcome. Subset analysis on healthy participants who consumed beetroot juice (BRJ) revealed stronger trends for NO3- improving VO2peak (p = 0.08) compared with TTE (p = 0.19), with no significant moderators. Sunset funnel plot revealed low statistical power in all trials. CONCLUSIONS: NO3- supplementation combined with exercise training may not enhance exercise outcomes such as VO2peak or TTE. A trend for greater improvement in VO2peak in healthy participants supplemented with BRJ may exist (p = 0.08). Overall, future studies in this area need increased sample sizes, more unified methodologies, longer training interventions, and examination of sex as a biological variable to strengthen conclusions.

9.
Am J Physiol Heart Circ Physiol ; 325(6): H1243-H1263, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37737729

RESUMO

This review proposes a biologically plausible working model for the relationship between the 24-h activity cycle (24-HAC) and cardiovascular disease. The 24-HAC encompasses moderate-to-vigorous physical activity (MVPA), light physical activity, sedentary behavior (SB), and sleep. MVPA confers the greatest relative cardioprotective effect, when considering MVPA represents just 2% of the day if physical activity guidelines (30 min/day) are met. While we have well-established guidelines for MVPA, those for the remaining activity behaviors are vague. The vague guidelines are attributable to our limited mechanistic understanding of the independent and additive effects of these behaviors on the cardiovascular system. Our proposed biological model places arterial stiffness, a measure of vascular aging, as the key intermediate outcome. Starting with prolonged exposure to SB or static standing, we propose that the reported transient increases in arterial stiffness are driven by a cascade of negative hemodynamic effects following venous pooling. The subsequent autonomic, metabolic, and hormonal changes further impair vascular function. Vascular dysfunction can be offset by using mechanistic-informed interruption strategies and by engaging in protective behaviors throughout the day. Physical activity, especially MVPA, can confer protection by chronically improving endothelial function and associated protective mechanisms. Conversely, poor sleep, especially in duration and quality, negatively affects hormonal, metabolic, autonomic, and hemodynamic variables that can confound the physiological responses to next-day activity behaviors. Our hope is that the proposed biologically plausible working model will assist in furthering our understanding of the effects of these complex, interrelated activity behaviors on the cardiovascular system.


Assuntos
Sistema Cardiovascular , Rigidez Vascular , Ciclos de Atividade , Exercício Físico/fisiologia , Sono/fisiologia , Acelerometria
10.
Am J Physiol Heart Circ Physiol ; 325(1): H145-H146, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37342016
11.
Artigo em Inglês | MEDLINE | ID: mdl-37239578

RESUMO

BACKGROUND: Yoga may help adults of all fitness levels increase their physical activity and decrease their cardiovascular disease risk. AIM: To determine if arterial stiffness is lower (beneficial) in yoga versus non-yoga participants. METHOD: This cross-sectional study included 202 yoga (48.4 + 14.1 years, 81% female) and 181 (42.8 + 14.1 years, 44% female) non-yoga participants. The primary outcome was carotid-femoral pulse wave velocity (cfPWV). The two groups were compared using analysis of covariance with adjustments for demographic (age and sex), hemodynamic (mean arterial pressure and heart rate), lifestyle (physical activity levels, sedentary behaviour, smoking status and perceived stress score) and cardiometabolic (waist-to-hip ratio, total cholesterol and fasting glucose) factors. RESULTS: Following adjustments, cfPWV was significantly lower in yoga compared to non-yoga participants with a mean difference: -0.28 m.s-1, (95% CI = -0.55 to 0.08). CONCLUSION: At a population level, yoga participation may assist with decreasing the risk of cardiovascular disease in adults.


Assuntos
Doenças Cardiovasculares , Rigidez Vascular , Adulto , Humanos , Feminino , Masculino , Doenças Cardiovasculares/epidemiologia , Rigidez Vascular/fisiologia , Estudos Transversais , Análise de Onda de Pulso , Pressão Arterial , Fatores de Risco , Pressão Sanguínea/fisiologia
12.
Front Cardiovasc Med ; 10: 1108219, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36824455

RESUMO

Objective: Pulse-wave velocity (PWV), a common measure of arterial stiffness, can be measured continuously and across multiple body sites using photoplethysmography (PPG). The objective was to determine whether a simple photoplethysmography PPG PWV method agrees with a referent device. Approach: Photoplethysmography heart-finger PWV (hfPWV) and heart-toe PWV (htPWV) were compared to oscillometric carotid-wrist PWV (cwPWV) and carotid-ankle PWV (caPWV) referent measurements, respectively. In 30 adults (24.6 ± 4.8 years, body mass index 25.2 ± 5.9 kg/m2, 18 female), three measurements were made: two supine baseline measurements (Base 1, Base 2) and one measurement (Tilt) 5 min after a modified head-up tilt test (mHUTT). Overall agreement and repeated measures agreement (change in PPG PWV from Base to Tilt vs. change in referent PWV from Base to Tilt) were calculated using linear mixed models. Agreement estimates were expressed as intra-class correlation coefficients (ICC). Main results: For hfPWV there was strong overall agreement (ICC: 0.77, 95%CI: 0.67-0.85), but negligible and non-significant repeated measures agreement (ICC: 0.10, 95%CI: -0.18 to 0.36). For htPWV, there was moderate overall agreement (ICC:0.50, 95%CI: 0.31-0.65) and strong repeated measures agreement (ICC: 0.81, 95%CI: 0.69-0.89). Significance: Photoplethysmography can continuously measure PWV at multiple arterial segments with moderate-strong overall agreement. While further work with upper-limb PPG PWV is needed, PPG can adequately capture acute changes in lower-limb PWV.

13.
Front Physiol ; 14: 1107456, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36818445

RESUMO

Exposure to acute prolonged sitting and consumption of a high fat (HF) meal have been shown to independently and additively impair central and peripheral cardiovascular function. This study sought to determine whether localized activity, namely leg fidgeting, offers a protective effect to these deleterious effects. Using a randomized crossover design with three trials, 18 healthy males sat uninterrupted for 180 min following the consumption of a low fat (LF, trial 1) or HF meal (trial 2). The third trial consisted of a HF meal but sitting was interrupted with 1 min of leg fidgeting (isolated bilateral plantar flexion) consisting of -250 taps per min every 5 min for the 180 min duration. Carotid-femoral pulse wave velocity (cfPWV), aortic-femoral stiffness gradient (af-SG), superficial femoral blood flow, shear-rate and PWVß, triglyceride concentrations and lower-limb venous pooling (HHb) were assessed pre and post sitting in all trials. General linear mixed model found that following the uninterrupted HF trial, there was a significant worsening of cfPWV (mean difference (MD) = 0.57 mˑs-1; d = 1.04) and the af-SG (MD = 0.14, d = 0.50), and femoral artery blood flow (MD = 18 mlˑmin-1; d = 0.48) and shear rate (MD = 15 S1; d = 0.67) decreased. However, leg fidgeting was enough to prevent the combined deleterious effects of prolonged sitting following a HF meal. As there were no significant changes in the LF trial, the HF meal maybe the predominant driver when uninterrupted sitting is combined with a HF meal.

14.
Contemp Clin Trials ; 125: 107048, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36509249

RESUMO

BACKGROUND: Sedentary behavior (SB) is a biologically distinct yet understudied cardiovascular disease risk (CVD) factor. However, specific public health policy regarding the optimal strategy for SB interruption is unavailable. This paper outlines the protocol for part I of the Sitting with Interruption and Whole-Body Cardiovascular Health (SWITCH) study, including the rationale, objectives, methodology, and next steps. We additionally detail practical considerations that went into the development of the NIH R01 grant supporting this research. METHODS: Healthy men and women (n = 56, aged 36-55) who are inactive (<90 min/wk. of moderate-to-vigorous intensity physical activities for past 3 months) and sedentary (sitting for >8 h/day), will be recruited for this randomized crossover trial. Specifically, participants will complete the following 4-h conditions: (i) SB with once/h 5 min walk break; (ii) SB with once/h 15 min stand break; (iii) SB with twice/h breaks (alternating 5 min walk and 15 min stand); and (iv) SB with no breaks (i.e., control). Focus group discussions will refine our socioecological SB reduction model. RESULTS: The primary outcome will be change in aortic arterial stiffness (i.e., pulse wave velocity; PWV, m/s) for each substitution strategy relative to the control (SB with no breaks) condition. CONCLUSIONS: The outcomes from this study will facilitate the design of a subsequent randomized controlled trial to test a mechanism-informed, feasible SB-reduction intervention and support the development of SB policy.


Assuntos
Exercício Físico , Rigidez Vascular , Masculino , Pessoa de Meia-Idade , Humanos , Adulto , Feminino , Análise de Onda de Pulso , Comportamento Sedentário , Fatores de Risco de Doenças Cardíacas , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
Am J Physiol Heart Circ Physiol ; 324(1): H122-H125, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36525481

RESUMO

Sedentary behavior has been identified as an independent predictor of future cardiovascular disease risk and all-cause mortality. To explain this association, a growing body of literature has sought to investigate the physiological underpinnings of this association with the goal of developing a biologically plausible model. In time, this biologically plausible model can be tested, and effective, translatable public health guidelines can be developed. However, to ensure that evidence across studies can be effectively synthesized, it is necessary to ensure their congruency and comparability. Although there are several key factors that should be considered and controlled across prolonged sitting studies, one pertinent issue is that of participant posture. There is currently a discourse within the literature regarding the posture that cardiovascular assessments are performed in and rest periods between posture transitions and subsequent measures. This perspectives piece makes the case for standardizing approaches across the research area and offers practical recommendations for future work.


Assuntos
Doenças Cardiovasculares , Comportamento Sedentário , Humanos , Doenças Cardiovasculares/diagnóstico , Postura/fisiologia , Postura Sentada , Fatores de Tempo
17.
Front Physiol ; 13: 962791, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35965885

RESUMO

A ubiquitous aspect of contemporary societies is sedentary behavior (SB), defined as low intensity activities in a seated, reclined, or supine posture. Leading public health agencies, including the World Health Organization, have recognized the strong association between SB and poor health outcomes, particularly cardiovascular disease. However, while public health agencies have begun to advocate for "reductions" in SB, the current US guidelines are typically vague and non-specific. There is good reasoning behind this non-committal advocacy-there is limited mechanistic and clinical evidence to support policy development. To guide SB policy development, it is important to first consider the origins and evolution of SB, including the following: 1) is SB really a novel/contemporary behavior? i.e., how has this behavior evolved? 2) how did our ancestors sit and in what contexts? 3) how does SB interact with 24-hour activity behaviors, including physical activity and sleep? 4) what other historical and contemporary facets of life interact with SB? and 5) in what context do these behaviors occur and how might they provide different evolutionarily novel stressors? This perspective article will synthesize the available evidence that addresses these questions and stimulate discussion pertaining to the lessons that we can learn from an historical and evolutionary perspective. Last, it will outline the gaps in current SB interruption literature that are hindering development of feasible SB reduction policy.

18.
Br J Surg ; 109(8): 686-694, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35552376

RESUMO

BACKGROUND: The aim was to determine the comparative benefits of structured high-pain exercise, structured low-pain exercise, and usual-care control, to identify which has the largest effect on walking ability in people with intermittent claudication (IC). METHODS: A network meta-analysis was undertaken to assess two outcomes: pain-free walking ability (PFWA) and maximal walking ability (MWA). Nine electronic databases were searched. Trials were included if they were: RCTS; involved adults with IC; had at least two of the following arms-structured low-pain exercise, structured high--pain exercise or usual-care control; and a maximal or pain-free treadmill walking outcome. RESULTS: Some 14 trials were included; results were pooled using the standardized mean difference (MD). Structured low-pain exercise had a significant large positive effect on MWA (MD 2.23, 95 percent c.i. 1.11 to 3.35) and PFWA (MD 2.26, 1.26 to 3.26) compared with usual-care control. Structured high-pain exercise had a significant large positive effect on MWA (MD 0.95, 0.20 to 1.70) and a moderate positive effect on PFWA (0.77, 0.01 to 1.53) compared with usual-care control. In an analysis of structured low- versus high pain exercise, there was a large positive effect in favour of low-pain exercise on MWA (MD 1.28, -0.07 to 2.62) and PFWA (1.50, 0.24 to 2.75); however, this was significant only for PFWA. CONCLUSION: There is strong evidence in support of use of structured high-pain exercise, and some evidence in support of structured low-pain exercise, to improve walking ability in people with IC compared with usual-care control (unstructured exercise advice).


Assuntos
Terapia por Exercício , Claudicação Intermitente , Adulto , Exercício Físico , Teste de Esforço , Terapia por Exercício/métodos , Humanos , Claudicação Intermitente/terapia , Dor , Caminhada
19.
Artigo em Inglês | MEDLINE | ID: mdl-35162381

RESUMO

Prolonged uninterrupted sitting and a typical Western meal, high in fat and refined sugar, can additively impair cognitive and cerebrovascular functions. However, it is unknown whether interrupting these behaviours, with a simple desk-based activity, can attenuate the impairment. The aim of this study was to determine whether regular leg fidgeting can off-set the detrimental effects of prolonged sitting following the consumption of a typical Western meal, on executive and cerebrovascular function. Using a randomized cross-over design, 13 healthy males consumed a Western meal and completed 180-min of prolonged sitting with leg fidgeting of 1 min on/4 min off (intervention [INT]) and without (control [CON]). Cognitive function was assessed pre and post sitting using the Trail Maker Test (TMT) parts A and B. Common carotid artery (CCA) blood flow, as an index of brain flow, was measured pre and post, and cerebral (FP1) perfusion was measured continuously. For TMT B the CON trial significantly increased (worsened) completion time (mean difference [MD] = 5.2 s, d = 0.38), the number of errors (MD = 3.33, d = 0.68) and cognitive fatigue (MD = 0.73, d = 0.92). Compared to CON, the INT trial significantly improved completion time (MD = 2.3 s, d = 0.97), and prevented declines in cognitive fatigue and a reduction in the number of errors. No significant changes in cerebral perfusion or CCA blood flow were found. Leg fidgeting for 1-min on/4-min off following a meal high in fats and refined sugars attenuated the impairment in executive function. This attenuation in executive function may not be caused by alterations in CCA blood flow or cerebral perfusion.


Assuntos
Função Executiva , Perna (Membro) , Artérias Carótidas , Estudos Cross-Over , Função Executiva/fisiologia , Humanos , Masculino , Refeições
20.
Atherosclerosis ; 340: 53-60, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34799100

RESUMO

BACKGROUND & AIMS: Atherosclerosis and arteriosclerosis contribute to vascular aging and cardiovascular disease (CVD) risk. Both processes can be assessed simply in the lower-limbs and reflect systemic pathology. However, only atherosclerosis is routinely assessed, typically via ankle-brachial index (ABI). Arteriosclerosis can be assessed using femoral-ankle pulse wave velocity (faPWV), but no studies have identified whether ABI and faPWV similarly associate with overt CVD and risk factors, nor whether faPWV confers additional information. The aims of this study were to (i) compare associations of ABI and faPWV with traditional CVD risk factors, including age, sex, systolic blood pressure (SBP), high-density lipoprotein (HDL), total cholesterol (TC), smoking, and diabetes; and (ii) determine the independent and additive associations of ABI and faPWV with a composite measure of prevalent CVD. METHODS: We evaluated ABI and faPWV in 4330 older-aged (75.3 ± 5.0 years) adults using an oscillometric screening device. Associations between ABI and faPWV with CVD risk factors and CVD were determined using mixed-model linear- and logistic-regression. RESULTS: ABI and faPWV were associated with age, HDL, and smoking. ABI was associated with sex, TC, diabetes. faPWV was associated with SBP. Both ABI and faPWV were inversely associated with CVD. Low ABI (≤0.9 vs. >0.9) and low faPWV (≤9.94 vs. >9.94) increased the odds of CVD by 2.41-fold (95% CI:1.85,3.17) and 1.46-fold (95% CI:1.23,1.74), respectively. The inverse association between faPWV and CVD was independent of ABI and CVD risk factors. CONCLUSIONS: ABI and faPWV, measures of lower-limb atherosclerosis and arteriosclerosis, are independently associated with CVD risk factors and prevalent CVD. Assessment of faPWV may confer additional risk information beyond ABI.


Assuntos
Aterosclerose , Doenças Cardiovasculares , Idoso , Índice Tornozelo-Braço , Aterosclerose/diagnóstico , Aterosclerose/epidemiologia , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Fatores de Risco de Doenças Cardíacas , Humanos , Análise de Onda de Pulso , Fatores de Risco
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