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Background: The association between sedentary behavior (SB) and cardiometabolic risk may differ by SB domain and context. Nonoccupational SB is particularly important because it is discretionary and more amenable to change. This study estimated associations of nonoccupational SB contexts with hypertension (HTN) and diabetes mellitus (DM)., Methods: A total of 3370 middle-aged adults (50.1 ± 3.6 years; 56% F) from the Coronary Artery Risk Development in Young Adults (CARDIA) study were included. Cross-sectional and 5-year prospective associations between self-report total SB and 6 context-specific SBs (television-TV, computer, transportation, phone, music, and paperwork) with HTN and DM were tested using logistic regression. Fully adjusted models controlled for sociodemographic variables, body mass index, and self-report moderate-vigorous intensity physical activity., Results: Prevalences of HTN and DM at baseline were 48% (1618 cases) and 10% (320 cases), respectively. Each hour per day of total-SB was cross-sectionally associated with HTN (OR: 1.03, 95% CI, 1.01-1.05) but not DM, with nonsignificant prospective associations for HTN and DM. Of the context-specific SBs, only TV-SB was significantly associated with HTN or DM. Each hour of TV-SB was cross-sectionally associated with HTN (OR: 1.09, 95% CI, 1.03-1.15) and DM (OR: 1.18, 95% CI, 1.09-1.29), and prospectively with HTN (OR: 1.14, 95% CI, 1.04-1.26) but not DM., Conclusion: When comparing total-SB and the 6 context-specific SBs, TV-SB was most robustly associated with HTN. The findings were less clear for DM. Behavior change strategies that target TV-SB reduction may be effective at reducing HTN risk in middle-aged adults., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Behavioral Medicine.)

Background: The aortic-femoral arterial stiffness gradient, calculated as the ratio of lower-limb pulse-wave velocity (PWV) to central (aortic) PWV, is a promising tool for assessing cardiovascular disease (CVD) risk, but whether it predicts incident CVD is unknown., Methods: We examined the association of the aortic-femoral arterial stiffness gradient measures carotid-femoral stiffness gradient (femoral-ankle PWV divided by carotid-femoral PWV) and the heart-femoral stiffness gradient (femoral-ankle PWV divided by heart-femoral PWV), as well as PWV, with incident CVD (coronary disease, stroke, and heart failure) and all-cause mortality among 3109 participants of the Atherosclerosis Risk in Communities Study cohort (age, 75±5 years; carotid-femoral PWV, 11.5±3.0 m/s), free of CVD. Cox regression was used to estimate hazard ratios (HR) and 95% CIs., Results: Over a median 7.4-year follow-up, there were 322 cases of incident CVD and 410 deaths. In fully adjusted models, only top quartiles of carotid-femoral stiffness gradient (quartile 4: HR, 1.43 [95% CI, 1.03-1.97]; and quartile 3: HR, 1.49 [95% CI, 1.08-2.05]) and heart-femoral stiffness gradient (quartile 4: HR, 1.77 [95% CI, 1.27-2.48]; and quartile 3: HR, 1.41 [95% CI, 1.00-2.00]) were significantly associated with a greater risk of incident CVD. Only high aortic stiffness in combination with low lower-limb stiffness was significantly associated with incident CVD (HR, 1.46 [95% CI, 1.06-2.02]) compared with the referent low aortic stiffness and high lower-limb stiffness. No PWVs were significantly associated with incident CVD. No exposures were associated with all-cause mortality., Conclusions: The aortic-femoral arterial stiffness gradient may enhance CVD risk assessment in older adults in whom the predictive capacity of traditional risk factors and PWV are attenuated., Competing Interests: None.

Central adiposity, which is visceral and subcutaneous adiposity in the abdominal region, is a known risk factor for developing chronic cardiometabolic diseases. Central adiposity can be measured relatively inexpensively using ultrasound. Ultrasound has been shown to be precise and reliable, with measurement accuracy comparable to computed tomography and magnetic resonance. Despite the advantages conferred by ultrasound, widespread adoption has been hindered by lack of reliable standard operating procedures. To consolidate the literature and bring clarity to the use of ultrasound-derived measures of central adiposity, this review outlines (i) the [patho]physiological importance of central adiposity to cardiometabolic disease risk; (ii) an overview of the history and main technical aspects of ultrasound methodology; (iii) key measurement considerations, including transducer selection, subject preparation, image acquisition, image analysis, and operator training; and (iv) guidelines for standardized ultrasound protocols for measuring central adiposity., (© 2024 World Obesity Federation.)

Background: Cardiometabolic disease (CMD) risk often begins early in life. Healthy lifestyle behaviors can mitigate risk, but the optimal combination of behaviors has not been determined. This cross-sectional study simultaneously examined the associations between lifestyle factors (fitness, activity behaviors, and dietary patterns) and CMD risk in preadolescent children., Methods: 1480 New Zealand children aged 8-10 years were recruited. Participants included 316 preadolescents (50% female, age: 9.5 ± 1.1 years, BMI: 17.9 ± 3.3 kg/m 2 ). Fitness (cardiorespiratory fitness [CRF], muscular fitness), activity behaviors (physical activity, sedentary, sleep), and dietary patterns were measured. Factor analysis was used to derive a CMD risk score from 13 variables (adiposity, peripheral and central hemodynamics, glycemic control, and blood lipids)., Results: Only CRF (β = -0.45, p < 0.001) and sedentary time (β = 0.12, p = 0.019) were associated with the CMD risk score in the adjusted multivariable analysis. CRF was found to be nonlinear (VO 2 max ≤ ≈42 mL/kg/min associated with higher CMD risk score), and thus a CRF polynomial term was added, which was also associated (β = 0.19, p < 0.001) with the CMD risk score. Significant associations were not found with sleep or dietary variables., Conclusion: The findings indicate that increasing CRF and decreasing sedentary behavior may be important public health targets in preadolescent children.

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/m 2 , 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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zieff, Stone, Paterson, Fryer, Diana, Blackwell, Meyer and Stoner.)

Lifestyle factors contribute to childhood obesity risk, however it is unclear which lifestyle factors are most strongly associated with childhood obesity. The purpose of this cross-sectional study was to simultaneously investigate the associations among dietary patterns, activity behaviors, and physical fitness with adiposity (body fat %, fat mass, body mass index [BMI], and waist to hip ratio) in preadolescent children. Preadolescent children (N = 392, 50% female, age: 9.5 ± 1.1year, BMI: 17.9 ± 3.3 kg/m2) were recruited. Body fat (%) and fat mass (kg) were measured with bioelectrical impedance analysis. Cardiorespiratory fitness (VO2 max), muscular strength (hand-grip strength), activity, sleep, and dietary pattern was assessed. Multivariable analysis revealed that cardiorespiratory fitness associated most strongly with all four indicators of adiposity (body fat (%) (β = -0.2; p < .001), fat mass (β = -0.2; p < .001), BMI (β = -0.1; p < .001) and waist to hip ratio (β = -0.2; p < .001). Additionally, fruit and vegetable consumption patterns were associated with body fat percentage, but the association was negligible (β = 0.1; p = 0.015). Therefore, future interventions should aim to promote the use of cardiorespiratory fitness as a means of reducing the obesity epidemic in children., Competing Interests: The authors have declared that no competing interests exist.

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.

People with spinal cord injury (SCI) face unique challenges during the COVID-19 pandemic, including greater risk of poor COVID-19-related outcomes, increased social isolation, and restricted access to important services. Furthermore, COVID-19 related restrictions have decreased already low levels of physical activity (PA) in this population. Therefore, the purpose of this commentary is to: 1) address the impact of COVID-19 on PA and sedentary behavior (SB) in people with SCI; 2) provide potential SB reduction strategies to guide future research; and 3) provide recommendations to increase PA and reduce SB on behalf of the American College of Sports Medicine Exercise is Medicine (ACSM-EIM) and Healthy Living for Pandemic Event Protection (HL-PIVOT) using a social-ecological model targeting the individual-, social environment-, physical environment-, and policy-level determinants of behavior in people with SCI., (Copyright © 2021. Published by Elsevier Inc.)

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., (Copyright © 2021. Published by Elsevier B.V.)

Background: Aortic arterial stiffness is a strong independent predictor of cardiovascular disease (CVD); however, its dependence on mean arterial pressure (MAP) limits its clinical utility. The aortic-femoral arterial stiffness gradient (af-SG), a novel marker of CVD risk, may be a promising alternative, but its dependence on MAP is not known. The aim of this study was to determine the relationship between MAP and the af-SG in healthy older adults and those with established disease, including hypertension and diabetes., Method: We evaluated the dependency of the af-SG on MAP in healthy older adults (n = 694, aged 74 ± 5 years), and adults with hypertension (n = 2040, aged 76 ± 5 years), and diabetes (n = 1405, aged 75 ± 5 years) as part of the community-based Atherosclerosis Risk in Communities (ARIC) Study. Carotid-femoral pulse-wave velocity (cfPWV), femoral-ankle PWV (faPWV) and blood pressure were measured using standardized protocols. The af-SG was calculated as faPWV divided by cfPWV. Multivariable regression analysis was performed to test the independent association of MAP with af-SG, with adjustments for known confounders, including age, sex, BMI, blood glucose and heart rate., Results: There was no significant relationship between the af-SG and MAP in healthy (β = 0.002, P = 0.301), hypertension (β = -0.001, P = 0.298) or diabetes (β = -0.001, P = 0.063) population groups, with MAP explaining less than 0.1, less than 0.1 and 0.2% of the variance in the af-SG, respectively., Conclusion: These findings suggest that the af-SG may be regarded as a MAP independent index of arterial health and CVD risk in older adults., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Ghrelin is a gut hormone with numerous physiological effects, including the regulation of energy balance, insulin sensitivity, vascular health, and body composition. Acylated (AG) and des-acylated (DAG) ghrelin constitute approximately 22 % and 78 % of total plasma ghrelin (TG), respectively. Alterations in the TG concentration and the AG/DAG ratio may be implicated in conditions involving energy imbalances and insulin resistant states (e.g., metabolic syndrome or Type 2 diabetes mellitus). Exercise is a therapeutic option that can potentially optimize ghrelin levels. Understanding the precise intensity and dose of exercise to optimize ghrelin levels may lead to targeted interventions to restore metabolic regulation in obesity and other clinical conditions., Objective: To perform a systematic review and meta-analysis on the effects of acute exercise on pre-prandial levels of TG, AG, and DAG in healthy adults and to determine if sample demographics or exercise doses moderate such effects., Methods: Electronic databases (PubMed, Medline, SPORTDiscus, Web of Science, and Google Scholar) were searched with articles published through August 2020. The following criteria was determined a priori for article inclusion: (i) the study was a randomized controlled trial (RCT),(ii) exercise was an acute bout, (iii) the exercise bout for the intervention group(s)/condition was structured, (iv) the control group/condition received no exercise, (v) participants were adults age 18 or older, (vi) ghrelin was sampled through blood, (vii) there was at least one baseline measure and one post-exercise measure of ghrelin, (viii) there were at least 3 timepoints where ghrelin was measured while participants were fasted to allow for pre-prandial total area-under-the-curve (AUC total ) calculation, (ix) participants were healthy with no overt disease, (x) interventions were carried out without any environmental manipulations. Standardized mean difference (SMD) with 95 % confidence intervals were calculated using the restricted maximum likelihood estimation Moderator analyses to determine whether the overall pooled effect was influenced by: sex, ghrelin form, method of ghrelin analysis, age, body mass index, body fat percentage, fitness, intensity of exercise bout, duration of exercise bout, energy expenditure, and length of AUC total data., Results: The analysis included 24 studies that consisted of 52 trials, n = 504 (age 27.0 (8.8) years, BMI 24.7 (2.7) kg/m 2 ) and measured AG (n = 38 trials), DAG (n = 7), and TG (n = 7). The overall model indicated that exercise lowered ghrelin levels compared to control (no exercise); (SMD=-0.44, p < 0.001), and exercise intensity exhibited an inverse relationship with ghrelin levels (regression coefficient (ß)=-0.016, p = 0.04). There was no significant difference by ghrelin form (p = 0.18)., Discussion: Acute exercise significantly lowers plasma ghrelin levels, with higher intensity exercise associated with greater ghrelin suppression. The majority of studies applied a moderate intensity exercise bout and measured AG, with limited data on DAG. This exercise dose may be clinically significant in individuals with metabolic dysregulation and energy imbalance as a therapy to optimize AG levels. More work is needed to compare moderate and high intensity exercise and the ghrelin response in clinical populations., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Independently, prolonged uninterrupted sitting and the consumption of a meal high in saturated fats acutely disrupt normal cardiovascular function. Currently, the acute effects of these behaviors performed in combination on arterial stiffness, a marker of cardiovascular health, are unknown. This study sought to determine the effect of consuming a high-fat meal (Δ = 51 g fat) in conjunction with prolonged uninterrupted sitting (180 min) on measures of central and peripheral arterial stiffness. Using a randomized crossover design, 13 young healthy males consumed a high-fat (61 g) or low-fat (10 g) meal before 180 min of uninterrupted sitting. Carotid-femoral (cf) and femoral-ankle (fa) pulse wave velocity (PWV), aortic-femoral stiffness gradient (af-SG), superficial femoral PWV beta (β), and oscillometric pulse wave analysis outcomes were assessed pre and post sitting. cfPWV increased significantly more following the high-fat (mean difference [MD] = 0.59 m·s -1 ) meal than following the low-fat (MD = 0.2 m·s -1 ) meal, with no change in faPWV in either condition. The af-SG significantly decreased (worsened) (η p 2  = 0.569) over time in the high- and low-fat conditions (ratio = 0.1 and 0.1, respectively). Superficial femoral PWV β significantly increased over time in the high- and low-fat conditions (η p 2  = 0.321; 0.8 and 0.4 m·s -1 , respectively). Triglycerides increased over time in the high-fat trial only (η p 2  = 0.761). There were no significant changes in blood pressure. Consuming a high-fat meal prior to 180 min of uninterrupted sitting augments markers of cardiovascular disease risk more than consuming a low-fat meal prior to sitting., (© 2021. The Author(s).)

Increased sedentary behavior has been an unintended consequence of social and physical distancing restrictions needed to limit transmission of SARS-CoV-2, the novel coronavirus that causes COVID-19. Sedentary behavior is defined as any waking behavior characterized by an energy expenditure ≤1.5 metabolic equivalents (METs), while in a sitting, reclining, or lying posture. These restrictions negatively impact peoples' cardiometabolic and mental health and disproportionately affect certain sectors of the population, including racial/ethnic minorities. In part, the higher risk for complications of COVID-19 could be the result of increased prevalence of comorbid diseases. Further, regular participation and adherence to current physical activity guidelines, defined as at least 150 minutes per week of moderate intensity physical activity or muscle strengthening activities on 2 or more days a week, is challenging for many and may be especially difficult to achieve during the COVID-19 pandemic. A practical strategy to promote health and well-being during COVID-19 is reducing sedentary behavior. Reducing sedentary behaviors (e.g., breaking up periods of prolonged sitting with light-intensity physical activity) may be more easily achieved than physical activity for all individuals, including individuals of racial/ethnic decent, as it does not require purchasing equipment nor require compromising the physical restrictions necessary to slow the spread of COVID-19. The purpose of this commentary is to argue that sedentary behavior is a feasible, independent target to modify during COVID-19, particularly in minority populations, and to address this behavior we need to consider individual, environmental and policy-level factors., Competing Interests: Conflicts of interest: NONE

Preventative measures taken worldwide to decrease the transmission of COVID-19 have had a tremendous impact on youth. Following social restrictions, youth with and without physical disabilities are engaging in less physical activity, more increased sedentary behavior, and poor sleep habits. Specifically, youth wheelchair users (YWU) are likely disproportionately affected by COVID- 19 and have a higher risk of contraction due to underlying comorbidities. While we cannot control all of the negative long-term implications of COVID-19 for YWU, participation in positive 24-h activity behaviors can decrease chronic disease risk and the likelihood of long-term complications resulting from infection. This commentary is to extend the discourse on the importance of 24-h activity behaviors by focusing on YWU. Specifically, we discuss the importance of chronic disease prevention, provide a brief overview of 24-h activity behaviors, and outline some of the lessons that can be learned from the COVID-19 pandemic.

Background: The aortic to femoral arterial stiffness gradient (af-SG) may be a novel measure of arterial health and cardiovascular disease (CVD) risk, but its association with CVD risk factors and CVD status, and whether or not they differ from the referent measure, carotid-femoral pulse-wave velocity (cfPWV), is not known., Method: Accordingly, we compared the associations of the af-SG and cfPWV with (i) age and traditional CVD risk factors and (ii) CVD status. We evaluated 4183 older-aged (75.2 ± 5.0 years) men and women in the community-based Atherosclerosis Risk in Communities (ARIC) Study. cfPWV and femoral-ankle PWV (faPWV) were measured using an automated cardiovascular screening device. The af-SG was calculated as faPWV divided by cfPWV. Associations of af-SG and cfPWV with age, CVD risk factors (age, BMI, blood pressure, heart rate, glucose and blood lipid levels) and CVD status (hypertension, diabetes, coronary heart disease, heart failure, stroke) were determined using linear and logistic regression analyses., Results: (i) the af-SG and cfPWV demonstrated comparable associations with age and CVD risk factors, except BMI. (ii) a low af-SG was associated with diabetes, coronary heart disease, heart failure and stroke, whilst a high cfPWV was only associated with diabetes., Conclusion: Although future studies are necessary to confirm clinical utility, the af-SG is a promising tool that may provide a unique picture of hemodynamic integration and identification of CVD risk when compared with cfPWV., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Sedentary behavior is associated with poor physical and mental health. Targeting sedentary behavior is a simple strategy that may help counter physical and mental health concerns associated with COVID-19-related social restrictions. Of course, traditional strategies such as achieving optimal exercise and physical activity levels are also important and should be recommended. However, even under normal circumstances, the difficulty in promoting lasting exercise habits at multiple levels (e.g. individual, environment, policy) are well documented, and chances of maintaining or improving these factors is now even lower. Thus, relative to other lifestyle behaviors - sedentary behavior may be more amenable to change. Moreover, reducing sedentary behavior may be less susceptible to influence from factors associated with health disparities such as age, race, and socio-economic status compared to exercise or physical activity. Sedentary behavior is a feasible health strategy that should be targeted during COVID-19., (© Society of Behavioral Medicine 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Carotid-femoral pulse-wave velocity (cfPWV) is the reference standard measure of central arterial stiffness. However, it requires assessment of the carotid artery, which is technically challenging, and subject-level factors, including carotid artery plaque, may confound measurements. A promising alternative that overcomes these limitations is heart-femoral PWV (hfPWV), but it is not known to what extent changes in cfPWV and hfPWV are associated. Objectives: To determine, (1) the strength of the association between hfPWV and cfPWV; and (2) whether change in hfPWV is associated with change in cfPWV when central arterial stiffness is perturbed. Methods: Twenty young, healthy adults [24.0 (SD: 3.1) years, 45% female] were recruited. hfPWV and cfPWV were determined using Doppler ultrasound at baseline and following a mechanical perturbation in arterial stiffness (120 mmHg thigh occlusion). Agreement between the two measurements was determined using mixed-effects regression models and Bland-Altman analysis. Results: There was, (1) strong (ICC > 0.7) agreement between hfPWV and cfPWV (ICC = 0.82, 95%CI: 0.69, 0.90), and, (2) very strong (ICC > 0.9) agreement between change in hfPWV and cfPWV (ICC = 0.92, 95%CI: 0.86, 0.96). cfPWV was significantly greater than hfPWV at baseline and during thigh occlusion ( both P < 0.001). Inspection of the Bland-Altman plot, comparing cfPWV and corrected hfPWV, revealed no measurement magnitude bias. Discussion: The current findings indicate that hfPWV and cfPWV are strongly associated, and that change in cfPWV is very strongly associated with change in hfPWV. hfPWV may be a simple alternative to cfPWV in the identification of cardiovascular risk in clinical and epidemiological settings., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Stone, Fryer, Faulkner, Meyer, Zieff, Paterson, Burnet, Kelsch, Credeur, Lambrick and Stoner.)

Background: Exposure to acute prolonged sitting can result in vascular dysfunction, particularly within the legs. This vascular dysfunction, assessed using flow-mediated dilation (FMD), is likely the consequence of decreased blood flow-induced shear stress. With mixed success, several sitting interruption strategies have been trialled to preserve vascular function., Objectives: The objectives of this meta-analysis were to (1) assess the effects of acute prolonged sitting exposure on vascular function in the upper- and lower-limb arteries, and (2) evaluate the effectiveness of sitting interruption strategies in preserving vascular function. Sub-group analyses were conducted to determine whether artery location or interruption modality explain heterogeneity., Data Sources: Electronic databases (PubMed, Web of Science, SPORTDiscus, and Google Scholar) were searched from inception to January 2020. Reference lists of eligible studies and relevant reviews were also checked., Study Selection: Inclusion criteria for objective (1) were: (i) FMD% was assessed pre- and post-sitting; (ii) studies were either randomised-controlled, randomised-crossover, or quasi-experimental trials; (iii) the sitting period was ≥ 1 h; and (iv) participants were healthy non-smoking adults (≥ 18 years), and free of vascular-acting medication and disease at the time of testing. Additional inclusion criteria for objective (2) were: (i) the interruption strategy must have been during the sitting period; (ii) there was a control (uninterrupted sitting) group/arm; and (iii) the interruption strategy must have involved the participants actively moving their lower- or upper-limbs., Appraisal and Synthesis Methods: One thousand eight hundred and two articles were identified, of which 17 (22 trials, n = 269) met inclusion criteria for objective (1). Of those 17 articles, 6 studies (9 trials, n = 127) met the inclusion criteria for objective (2). Weighted mean differences (WMD), 95% confidence intervals (95% CI), and standardised mean difference (SMD) were calculated for all trials using random-effects meta-analysis modelling. SMD was used to determine the magnitude of effect, where < 0.2, 0.2, 0.5, and 0.8 was defined as trivial, small, moderate, and large respectively., Results: (1) Random-effects modelling showed uninterrupted bouts of prolonged sitting resulted in a significant decrease in FMD% (WMD = - 2.12%, 95% CI - 2.66 to - 1.59, SMD = 0.84). Subgroup analysis revealed reductions in lower- but not upper-limb FMD%. (2) Random-effects modelling showed that interrupting bouts of sitting resulted in a significantly higher FMD% compared to uninterrupted sitting (WMD = 1.91%, 95% CI 0.40 to 3.42, SMD = 0.57). Subgroup analyses failed to identify an optimum interruption strategy but revealed moderate non-significant effects for aerobic interventions (WMD = 2.17%, 95% CI - 0.34 to 4.67, SMD = 0.69) and simple resistance activities (WMD = 2.40%, 95% CI - 0.08 to 4.88, SMD = 0.55) and a trivial effect for standing interruptions (WMD = 0.24%, 95% CI - 0.90 to 1.38, SMD = 0.16)., Conclusions: Exposure to acute prolonged sitting leads to significant vascular dysfunction in arteries of the lower, but not upper, limbs. The limited available data indicate that vascular dysfunction can be prevented by regularly interrupting sitting, particularly with aerobic or simple resistance activities.

This commentary offers discussion on the pros and cons of universal healthcare in the United States. Disadvantages of universal healthcare include significant upfront costs and logistical challenges. On the other hand, universal healthcare may lead to a healthier populace, and thus, in the long-term, help to mitigate the economic costs of an unhealthy nation. In particular, substantial health disparities exist in the United States, with low socio-economic status segments of the population subject to decreased access to quality healthcare and increased risk of non-communicable chronic conditions such as obesity and type II diabetes, among other determinants of poor health. While the implementation of universal healthcare would be complicated and challenging, we argue that shifting from a market-based system to a universal healthcare system is necessary. Universal healthcare will better facilitate and encourage sustainable, preventive health practices and be more advantageous for the long-term public health and economy of the United States.

Flow-mediated slowing (FMS), defined as the minimum pulse wave velocity (PWV min ) during reactive hyperemia, is potentially a simple, user-objective test for examining endothelial function. The purpose of the current study was to determine the effects of a known endothelial dysfunction protocol on arm PWV and PWV min . Complete data were successfully collected in 22 out of 23 healthy adults (23.8 years [SD 4.1], 16 F, 22.8 kg/m 2 [SD 2.8]). Local endothelial dysfunction was induced by increasing retrograde shear stress in the upper arm, through inflation of a distal (forearm) tourniquet to 75 mmHg, for 30 min. Pre- and post-endothelial dysfunction, PWV was measured followed by simultaneous assessment of PWV min and flow-mediated dilation (FMD). PWV was measured between the upper arm and wrist using an oscillometric device, and brachial FMD using ultrasound. FMD (%) and PWV min (m/s) were calculated as the maximum increase in diameter and minimum PWV during reactive hyperemia, respectively. Endothelial dysfunction resulted in a large effect size (ES) decrease in FMD (∆ = -3.10%; 95% CI: -4.15, -2.05; ES = -1.3), and a moderate increase in PWV (∆ = 0.38 m/s; 95% CI: 0.07, 0.69; ES = 0.5) and PWV min (∆ = 0.16 m/s; 95% CI: 0.05, 0.28; ES = 0.6). There was a large intra-individual (pre- vs post-endothelial dysfunction) association between FMD and PWV min ( r = -0.61; 95% CI: -0.82, -0.24). In conclusion, acute change in PWV and PWV min are at least partially driven by changes in endothelial function.

In the wake of the COVID-19 pandemic, social restrictions to contain the spread of the virus have disrupted behaviors across the 24-h day including physical activity, sedentary behavior, and sleep among children (5-12 years old) and adolescents (13-17 years old). Preliminary evidence reports significant decreases in physical activity, increases in sedentary behavior, and disrupted sleep schedules/sleep quality in children and adolescents. This commentary discusses the impact of COVID-19-related restrictions on behaviors across the 24-h day in children and adolescents. Furthermore, we suggest recommendations through the lens of a socio-ecological model to provide strategies for lasting behavior change to insure the health and well-being of children and adolescents during the COVID-19 pandemic.

Background: Carotid-femoral pulse wave velocity (cfPWV) is widely used in epidemiological studies to assess central arterial stiffness. However, despite being superior to traditional risk factors in predicting cardiovascular outcomes, cfPWV is not routinely used in clinical practice. cfPWV assessments require applanation of the carotid artery, which can be cumbersome, and individual-level factors, including carotid artery plaque, may confound the measurements. Heart-femoral PWV (hfPWV) may be a suitable alternative measure of central arterial stiffness., Objectives: The aim of this study was to estimate the strength of the agreement between hfPWV and cfPWV., Methods: We evaluated 4133 older-aged [75.2 (5.0) years] African-American and white adults in the community-based Atherosclerosis Risk in Communities (ARIC) Study. cfPWV and hfPWV were measured using an automated cardiovascular screening device. Agreement between the two measurements was determined using Pearson's correlation coefficient (r), standard error of estimate (SEE) and Bland-Altman analysis., Results: There was a strong (r > 0.7) agreement between hfPWV and cfPWV (r = 0.83, 95% CI: 0.82-0.84). Although the mean cfPWV [11.5 m/s (SD: 3.0)] and hfPWV [11.5 m/s (SD: 2.3)] were comparable, the SEE was 1.7 m/s. Inspection of the Bland-Altman plot revealed greater variability and bias for higher PWV values, with higher PWV further away from the regression line., Discussion: Findings suggest good agreement between hfPWV and cfPWV. hfPWV is a simpler alternative to cfPWV that is less likely to be confounded by individual-level factors. Considering the greater variability for higher PWV values, further work is warranted to determine the importance of local artery mechanics to both measures.

There has been a great deal of interest into the effects of prolonged sitting on lower limb vascular function. However, most studies use flow-mediated dilation which is technically challenging. A simpler technique is pulse wave velocity (PWV) which can be estimated at any single arterial site of interest using a number of different calculations (Bramwell-hill [PWV BH ], β-stiffness index [PWV β ] and blood flow [PWV BF ]). Findings from this technique would be better inferred if they compare to a standard criterion 2-point PWV assessment. The current study used ultrasound to determine which estimation of single-point PWV is most valid. The criterion was traditional ECG-gated 2-point (superficial femoral [SF]-posterior tibialis [PT]) PWV. Single-point estimates were calculated at the SF and PT arteries in both supine and seated positions. Single-point PWV was considered valid if the aSEE was <1.0 m·s. Findings show that for both postural positions, the absolute standard error of estimates (aSEE) criterion of <1.0 m·s was not achieved in either the PT or SF arteries using any of the single-point PWV calculations. However, single-point calculations consistently demonstrated the lowest error at the SF artery using PWV β in both supine (SF aSEE = 1.7 vs. PT 2.7 m·s) and seated (SF aSEE = 1.5 vs. PT 3.0 m·s) positions. All single-point ΔPWV (supine - seated) calculations were higher in sitting, with PWV β having the closest agreement (ΔSF aSEE 1.7 m·s) to the 2-point criterion. Single-point PWV calculations do not directly reflect regional 2-point PWV. However, they are sensitive to change when moving from supine to seated positions., (© 2020 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.)

Pulse wave analysis (PWA) utilizes arm blood pressure (BP) waveforms to estimate aortic waveforms. The accuracy of central BP waveform estimation may be influenced by assessment site local haemodynamics. This study investigated whether local haemodynamic changes, induced via arm tilting ±30° relative to heart level, affect estimated central systolic BP (cSBP) and arterial wave reflection (central augmentation index, cAIx; aortic backward pressure wave, Pb). In 20 healthy adults (26.7 years [SD 5.2], 10 F) brachial BP waveforms were simultaneously recorded on experimental and control arms. The experimental arm was randomly repositioned three times (heart level, -30° heart level, +30° heart level), while the control arm remained fixed at heart level. For the experimental arm, arm repositioning resulted in a large (partial eta-squared > 0.14) effect size (ES) change in SBP (ES = 0.75, P < 0.001), cSBP (ES = 0.81, P < 0.001), and cAIx (ES = 0.75, P = 0.002), but not Pb (ES = 0.06, P = 0.38). In the control arm, cAIx (ES = 0.22, P = 0.013) but not SBP or cSBP significantly changed. Change in experimental arm cSBP was partially explained by brachial systolic blood velocity (P = 0.026) and mean diameter (P = 0.012), while change in cAIx was associated with brachial retrograde blood velocity (P = 0.020) and beta stiffness (P = 0.038). In conclusion, manipulation of assessment site local haemodynamics, including the blood velocity profile and local arterial stiffness, had a large effect on estimated cSBP and cAIx, but not on Pb. These findings do not invalidate PWA devices but do suggest that the accuracy of the estimated aortic pressure waveform is dependent on stable peripheral haemodynamics.

New Findings: What is the central question of this study? There is growing interest in the effects of sedentarism on central and peripheral cardiovascular health. To permit further investigation, including larger epidemiological studies, there is a need to identify arterial health assessment tools that are valid (accurate) and reliable (precise), yet practical. What is the main finding and its importance? Lower-limb vascular health (femoral-ankle pulse-wave velocity) can be determined in a supine position with accuracy and precision using an oscillometrically based device. This technology might help to improve our understanding of the pathological mechanisms linking cardiovascular disease to sedentarism, including the interaction between peripheral and central vasculature., Abstract: There is a growing interest in the deleterious effects of sedentary behaviour on lower-limb arterial health. To permit further investigation, including larger epidemiological studies, there is a need to identify lower-limb arterial health assessment tools that are valid and reliable, yet simple to administer. In this study, we sought to determine the validity and between-day reliability of femoral-ankle pulse-wave velocity (faPWV) measures obtained using an oscillometrically based device (SphygmocCor XCEL) in supine and seated positions. Doppler ultrasound was used as the criterion. A total of 47 healthy adults were recruited for validity (n = 32) and reliability (n = 15) analyses. Validity was determined by measuring faPWV in seated and supine positions using the XCEL and Doppler ultrasound devices, in a randomized order. Between-day reliability was determined by measuring seated and supine faPWV using the XCEL on three different mornings, separated by a maximum of 7 days. The validity criterion [absolute standard error of estimate (aSEE) < 1.0 m s -1 ] was met in the supine [aSEE = 0.8 m s -1 , 95% confidence interval (CI) 0.4-1.0], but not in the seated (aSEE = 1.2 m s -1 , 95% CI 1.1-1.2) position. Intraclass correlation coefficient (ICC) estimates revealed that the XCEL demonstrated good reliability in the supine position (ICC = 0.83, 95% CI 0.65-0.93), but poor reliability in the seated position (ICC = 0.29, 95% CI 0.23-0.63). The oscillometric XCEL device can be used to determine lower-limb pulse-wave velocity with acceptable validity and reliability in the conventionally recommended supine position, but not in the seated position., (© 2019 The Authors. Experimental Physiology © 2019 The Physiological Society.)

Background: Regulation of postprandial hyperglycemia is a major concern for individuals with type 2 diabetes. Exercise can reduce postprandial hyperglycemia by increasing contraction-mediated glucose uptake. However, there is no consensus with which to develop guidelines for optimal postprandial exercise timing and prescription., Objective: The current systematic review was conducted to consolidate the literature surrounding the effects of postprandial exercise on glucose regulation in individuals with type 2 diabetes., Methods: Electronic databases were searched on 17 February 2017. Inclusion criteria were: (1) trial was a randomized crossover trial; (2) subjects were diagnosed with type 2 diabetes; (3) a standardized meal was given; (4) exercise was initiated within three hours of the meal; (5) subjects were not treated with insulin., Results: Twelve studies met the inclusion criteria, involving 135 participants (108 males, 20 females, seven unknown). The included studies varied greatly in their timing, duration, intensity, modality, and glucose measures. Postprandial aerobic exercise (11 studies) decreased short-term glucose area under the curve by 3.4-26.6% and 24-h prevalence of hyperglycemia by 11.9-65%. Resistance exercise (two studies) decreased the short-term glucose area under the curve by 30% and 24-h prevalence of hyperglycemia by 35%., Conclusion: Postprandial exercise may be an effective way to improve glucose control in individuals with type 2 diabetes. The most consistent benefits were seen in long-duration (≥ 45 min), moderate-intensity aerobic exercise. Resistance training also appears to be an effective modality. We recommend that individuals with type 2 diabetes focus on increasing energy expenditure after the largest meal of the day. More research is needed in this area to confirm the results of this systematic review and to provide clinicians with specific exercise recommendations.

Cardiovascular disease (CVD) has been associated with chronic psychological stress. Unremittent psychological stress causes dysregulation of the sympathetic nervous system (SNS) and hypothalamic-pituitaryadrenal (HPA) axis, which collectively promotes inflammation, atherosclerosis, and subsequent CVD risk. Stress reduction techniques, such as mindfulness meditation, have been shown to improve some markers of HPA and SNS function at rest and in response to acute stressors, suggesting that such techniques, over time, may be cardioprotective. Therefore, it may be hypothesized that eight weeks of daily mindfulness meditation, compared to a non-mindful relaxation control, may provide a novel strategy to buffer stress responses in healthy and at-risk populations, thereby lowering the risk of chronic psychological stress and the associated CVD risk as measured by arterial stiffness. The current paper outlines methodological considerations for testing this hypothesis, including appropriate acute stressors, and measurement of SNS, HPA axis and cardiovascular function. If the hypothesis is correct, mindfulness meditation would complement healthy lifestyle techniques such as exercise and diet to prevent CVD risk., (Copyright © 2017 Elsevier Ltd. All rights reserved.)