Interrupting sitting acutely attenuates cardiometabolic risk markers in South Asian adults living with overweight and obesity.

PURPOSE: This study examined the acute effects of interrupting sitting with light-intensity walking on postprandial cardiometabolic risk markers in South Asian adults. METHODS: South Asians with overweight/obesity (n = 19; body mass index [BMI] > 23 kg·m-2) and normal-weight (n = 8; BMI 18.0-22.9 kg·m-2) aged 48.8 ± 5.6 years completed two, 5-h conditions: (1) prolonged sitting (SIT), and (2) interrupted sitting with 5-min bouts of light-intensity walking every 30-min (INT-SIT). Blood samples and resting expired air samples were collected throughout each condition. Statistical analyses were completed using linear mixed models. RESULTS: In participants with overweight/obesity, postprandial glucose, triglycerides (TAG) and metabolic load index (MLI) over time were lower, whereas resting substrate utilisation and resting energy expenditure (REE) were higher, in INT-SIT than SIT (all p ≤ 0.05). Compared with SIT (0.18 [95% CI 0.13, 0.22] kcal.min-1), INT-SIT (0.23 [95% CI 0.18, 0.27] kcal.min-1) increased postprandial REE iAUC in participants with overweight/obesity (p = 0.04, d = 0.51). Postprandial TAG concentrations over time were lower in INT-SIT versus SIT (p = 0.01, d = 30) in normal-weight participants, with no differences in any other outcomes for this sample group. CONCLUSION: These findings suggest that interrupting sitting with 5-min bouts of light walking every 30-min acutely attenuates cardiometabolic risk markers among South Asians living with overweight/obesity, whereas limited effects may be seen in individuals with normal-weight.

A-REST (Activity to Reduce Excessive Sitting Time): A Feasibility Trial to Reduce Prolonged Sitting in Police Staff.

The aim of this study was to evaluate the acceptability and feasibility of a theory-derived sedentary workplace intervention for police office staff. Twenty-four staff participated in an 8-week intervention (single arm, pre-post design) incorporating an education session, team competition with quick response (QR) codes, team trophy, weekly leaderboard newsletters, a self-monitoring phone app, and electronic prompt tools. The intervention supported participants to reduce and break up their sitting time with three minutes of incidental movement every 30 min at work. Feasibility and acceptability were assessed using mixed methods via the RE-AIM QuEST and PRECIS-2 frameworks. The intervention was highly pragmatic in terms of eligibility, organisation, adherence, outcome, and analysis. It was slightly less pragmatic on recruitment and setting. Delivery and follow-up were more explanatory. Reach and adoption indicators demonstrated feasibility among police staff, across a range of departments, who were demographically similar to participants in previous office-based multi-component interventions. The intervention was delivered mostly as planned with minor deviations from protocol (implementation fidelity). Participants perceived the intervention components as highly acceptable. Results showed improvements in workplace sitting and standing, as well as small improvements in weight and positive affect. Evaluation of the intervention in a fully powered randomised controlled trial to assess behaviour and health outcomes is recommended.

Evaluating a multi-component intervention to reduce and break up office workers' sitting with sit-stand desks using the APEASE criteria.

OBJECTIVE: Sedentary workplace interventions have had success in reducing excessive sitting time in office workers, but barriers to implementation and uptake remain. This study formally assessed a theory-derived, sit-stand desk intervention using the APEASE (Acceptability, Practicability, Effectiveness, Affordability, Side-effects, Equity) criteria. METHODS: Thirteen adults (eight female, mean age 38 ± 10 years) from the treatment arm of a sedentary behaviour intervention participated in semi-structured interviews. Thematic codes were inductively assigned to data items followed by deductive charting using the APEASE criteria. RESULTS: The intervention was highly acceptable, practicable, safe to deploy, and helped workers reduce workplace sitting time, though individual preferences and workload mediated engagement. Affordability of sit-stand desks and Equity of access were potential barriers to uptake. CONCLUSIONS: Through the lens of the APEASE criteria, this theory-derived, multi-component sit-stand desk intervention showed acceptability, practicability and effectiveness in reducing and breaking up sedentary time at work with minimal side effects. Using this approach with further tailoring and personalisation may help workers achieve greater reductions in workplace sitting, though affordability and equity should be considered further.

Sedentary Behaviour-A Target for the Prevention and Management of Cardiovascular Disease.

Cardiovascular disease (CVD) is highly prevalent and can lead to disability and premature mortality. Sedentary behaviour, defined as a low energy expenditure while sitting or lying down, has been identified as an independent risk factor for CVD. This article discusses (1) the association of total sedentary time and patterns of accumulating sedentary time with CVD risk markers, CVD incidence and mortality; (2) acute experimental evidence regarding the acute effects of reducing and breaking up sedentary time on CVD risk markers; and (3) the effectiveness of longer-term sedentary behaviour interventions on CVD risk. Findings suggest that under rigorously controlled laboratory and free-living conditions, breaking up sedentary time improves cardiovascular risk markers in individuals who are healthy, overweight or obese, or have impaired cardiovascular health. Breaking up sedentary time with walking may have the most widespread benefits, whereas standing breaks may be less effective, especially in healthy individuals. There is also growing evidence that sedentary behaviour interventions may benefit cardiovascular risk in the longer term (i.e., weeks to months). Reducing and breaking up sedentary time may, therefore, be considered a target for preventing and managing CVD. Further research is needed to determine the effectiveness of sedentary behaviour interventions over the long-term to appropriately inform guidelines for the management of CVD.

Perceived influences on reducing prolonged sitting in police staff: a qualitative investigation using the Theoretical Domains Framework and COM-B model.

BACKGROUND: Workplace interventions have shown promise for reducing sitting in office workers. Police office staff remain an understudied population group that work within a disciplined organisation with distinctive work tasks around public safety, potentially affecting their capability, opportunity, and motivation to change sitting behaviour. This study aimed to assess the perceived influences on reducing workplace sitting in non-operational, desk-based police staff in order to derive theoretical determinants for behaviour change. METHODS: Ten police staff from a single police force in Bedfordshire, England [eight female; 39.5 ± 11.5 years] took part in face-to-face semi-structured interviews lasting 46 ± 11 min on average. Thematic analysis identified key themes which were then mapped onto the Theoretical Domains Framework (TDF) and linked to the Capability, Opportunity, Motivation-Behaviour (COM-B) model. RESULTS: Seven themes were identified: 'Work tasks are seated', 'Social norm is to sit', 'Belief in ability to regulate behaviour', 'Knowledge of health risks', 'Organisational support', 'Impact on productivity', and 'Perceived autonomy for sitting reduction'. CONCLUSIONS: Awareness of behaviour and health impacts (Capability), social and physical support to sit less (Opportunity), and habit formation techniques (Motivation) are recommended considerations in sitting reduction workplace interventions for police staff.

The Prevalence of Daily Sedentary Time in South Asian Adults: A Systematic Review.

This study aimed to systematically review total daily sedentary time in South Asian adults. Seven electronic databases were searched, identifying relevant articles published in peer-reviewed journals between March 1990 and March 2021. The study was designed in accordance with PRISMA guidelines. Prospective or cross-sectional design studies reporting total daily sedentary time in South Asian adults (aged ≥18 years), reported in English, were included. Study quality and risk of bias were assessed, and the weighted mean total daily sedentary time was calculated. Fourteen full texts were included in this systematic review from studies that were conducted in Bangladesh, India, Norway, Singapore, and the United Kingdom. Pooled sedentary time across all studies was 424 ± 8 min/day. Sedentary time was measured using self-report questionnaires in seven studies, with a weighted mean daily sedentary time of 416 ± 19 min/day. Eight studies used accelerometers and inclinometers with a weighted mean sedentary time of 527 ± 11 min/day. South Asian adults spend a large proportion of their time being sedentary, especially when recorded using objective measures (~9 h/day). These findings suggest that South Asians are an important target population for public health efforts to reduced sedentary time, and researchers and practitioners should seek to standardise and carefully consider the tools used when measuring sedentary time in this population.

Effects of Interrupting Sitting with Use of a Treadmill Desk Versus Prolonged Sitting on Postural Stability.

High amounts of sitting increase the risk of non-communicable disease and mortality. Treadmill desks make it possible to reduce sitting during the desk-based worker's day. This study investigated the acute effect on postural stability of interrupting prolonged sitting with an accumulated 2-h of light-intensity treadmill desk walking. Twenty-one sedentary adults participated in this randomized acute crossover trial, with two 6.5 h conditions: 1) uninterrupted sitting and 2) interrupted sitting with accumulated 2 h light-intensity treadmill desk walking. Pre- and post-condition, participants performed four postural stability tests on a pressure plate (bipedal and unipedal standing stance, eyes open and eyes closed). Anteroposterior center of pressure amplitude showed a significant condition x time interaction in bipedal eyes closed (F(1,20)=4.62, p=0.046) and unipedal eyes open (F(1,20)=9.42, p=0.006) tests, and mediolateral center of pressure amplitude in bipedal eyes closed (F(1,20)=6.12, p=0.023) and bipedal eyes open (F(1,12)=5.55, p=0.029) tests. In the significant interactions, amplitude increased pre to post condition in the uninterrupted sitting condition. The accumulated 2 h light-intensity treadmill desk walking ameliorated the negative effect of 6.5 h prolonged sitting on postural sway, supporting workplace treadmill desk use.

The Effectiveness of Sedentary Behaviour Reduction Workplace Interventions on Cardiometabolic Risk Markers: A Systematic Review.

BACKGROUND: Sedentary behaviour is a risk factor for type 2 diabetes and cardiovascular disease. OBJECTIVES: The aims of this work were to systematically review the effects of workplace sedentary behaviour reduction interventions on cardiometabolic risk markers (primary aim) and identify the active behaviour change techniques (BCTs) by which these interventions work (secondary aim). METHODS: A systematic search of 11 databases for articles published up to 12 April 2019 yielded a total of 4255 unique titles, with 29 articles being identified for inclusion. Interventions were rated as very promising, quite promising or non-promising based on their effects on cardiometabolic risk markers compared with baseline and/or a comparison arm. Interventions were coded for BCTs used. To assess the relative effectiveness of BCTs, a promise ratio was calculated as the frequency of a BCT appearing in all promising interventions divided by its frequency of appearance in all non-promising interventions. RESULTS: A narrative synthesis included 29 published studies of varying study design and comprised of 30 interventions. Risk of bias was high for blinding and allocation concealment, moderate for random sequence generation, and low for outcome assessment. Nine interventions were very promising, 11 were quite promising, 10 were non-promising, and 10 active control groups did not experience cardiometabolic changes. Significant sedentary behaviour reductions were present in all but five studies where cardiometabolic risk markers improved. The BCTs of social comparison, problem solving, demonstration of the behaviour, goal setting (behaviour), behaviour substitution, and habit reversal, demonstrated moderate to high promise ratios. CONCLUSIONS: Workplace interventions show promise for improving cardiometabolic risk markers. The BCTs with the greatest promise of cardiometabolic risk marker improvements included social comparison, those related to individual habits, and behaviour goals. REGISTRATION: This systematic review was prospectively registered in PROSPERO (CRD42017072427).

Associations of Sitting Behavior Patterns With Cardiometabolic Risk in Children: The Sit Less for Health Cross-Sectional Study.

BACKGROUND: The objective of this study was to investigate the associations between sedentary behavior patterns and cardiometabolic risk in children using a monitor that accurately distinguishes between different postures. METHODS: In this cross-sectional study, 118 children (67 girls) aged 11-12 years had adiposity, blood pressure, lipids, and glucose measured, and then they wore an activPAL device to record sitting, standing, and stepping for 7 consecutive days. Data were analyzed using multiple linear regression. RESULTS: After adjustment for potential confounders and moderate to vigorous physical activity, the number of breaks in sitting was significantly negatively associated with adiposity (standardized ß ≥ -0.546; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (ß = 0.415; P ≤ .01). Time in prolonged sitting bouts was significantly negatively associated with adiposity (ß ≥ -0.577; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (ß = 0.432; P ≤ .05). Standing time was significantly negatively associated with adiposity (ß ≥ -0.270; P ≤ .05) and significantly positively associated with high-density lipoprotein cholesterol (ß = 0.312; P ≤ .05). CONCLUSIONS: This study suggests that increasing the number of breaks in sitting and increasing standing time are beneficially associated with cardiometabolic risk and should be considered in health promotion interventions in children.

Reducing prolonged sedentary time using a treadmill desk acutely improves cardiometabolic risk markers in male and female adults.

This study evaluated the acute effects of interrupting prolonged sitting with an accumulated 2 h of light-intensity walking on postprandial cardiometabolic risk markers. In this randomised crossover trial, 24 participants (twelve males) aged 18-55 years took part in two, 6.5 h conditions: 1) prolonged sitting (SIT) and 2) sitting interrupted hourly with 20 min light-intensity treadmill desk walking at between 1.2-3.5 km/h-1 (INT-SIT). Standardized meals were provided at 0 h and 3 h. Blood samples and blood pressure measures were taken hourly. Statistical analyses were completed using linear mixed models. Postprandial incremental area under the curve responses (mmol/L∙6.5 h) for glucose (4.52 [3.47, 5.56] and 6.66 [5.62, 7.71] for INT-SIT and SIT, respectively) and triglycerides (1.96 [0.96, 2.96] and 2.71 [1.70, 3.71] for INT-SIT and SIT, respectively) were significantly lower in INT-SIT than SIT. Mean systolic and diastolic blood pressure responses were lower by 3% and 4%, respectively, in INT-SIT than SIT (P < 0.05). There was no significant condition x sex interaction effect for any outcomes (P > 0.05). These findings suggest that interrupting sitting with an accumulated 2 h of light-intensity walking acutely improves cardiometabolic risk levels in males and females compared with prolonged sitting.

Appetite and gut hormone responses to moderate-intensity continuous exercise versus high-intensity interval exercise, in normoxic and hypoxic conditions.

This study investigated the effects of continuous moderate-intensity exercise (MIE) and high-intensity interval exercise (HIIE) in combination with short exposure to hypoxia on appetite and plasma concentrations of acylated ghrelin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). Twelve healthy males completed four, 2.6 h trials in a random order: (1) MIE-normoxia, (2) MIE-hypoxia, (3) HIIE-normoxia, and (4) HIIE-hypoxia. Exercise took place in an environmental chamber. During MIE, participants ran for 50 min at 70% of altitude-specific maximal oxygen uptake (V˙O2max) and during HIIE performed 6 × 3 min running at 90% V˙O2max interspersed with 6 × 3 min active recovery at 50% V˙O2max with a 7 min warm-up and cool-down at 70% V˙O2max (50 min total). In hypoxic trials, exercise was performed at a simulated altitude of 2980 m (14.5% O2). Exercise was completed after a standardised breakfast. A second meal standardised to 30% of participants' daily energy requirements was provided 45 min after exercise. Appetite was suppressed more in hypoxia than normoxia during exercise, post-exercise, and for the full 2.6 h trial period (linear mixed modelling, p <0.05). Plasma acylated ghrelin concentrations were lower in hypoxia than normoxia post-exercise and for the full 2.6 h trial period (p <0.05). PYY concentrations were higher in HIIE than MIE under hypoxic conditions during exercise (p = 0.042). No differences in GLP-1 were observed between conditions (p > 0.05). These findings demonstrate that short exposure to hypoxia causes suppressions in appetite and plasma acylated ghrelin concentrations. Furthermore, appetite responses to exercise do not appear to be influenced by exercise modality.

Complex interactions of HIV-1 nucleocapsid protein with oligonucleotides.

The HIV-1 nucleocapsid (NC) protein is a small, basic protein containing two retroviral zinc fingers. It is a highly active nucleic acid chaperone; because of this activity, it plays a crucial role in virus replication as a cofactor during reverse transcription, and is probably important in other steps of the replication cycle as well. We previously reported that NC binds with high-affinity to the repeating sequence d(TG)n. We have now analyzed the interaction between NC and d(TG)4 in considerable detail, using surface plasmon resonance (SPR), tryptophan fluorescence quenching (TFQ), fluorescence anisotropy (FA), isothermal titration calorimetry (ITC) and electrospray ionization Fourier transform mass spectrometry (ESI-FTMS). Our results show that the interactions between these two molecules are surprisngly complex: while the K(d) for binding of a single d(TG)4 molecule to NC is only approximately 5 nM in 150 mM NaCl, a single NC molecule is capable of interacting with more than one d(TG)4 molecule, and conversely, more than one NC molecule can bind to a single d(TG)4 molecule. The strengths of these additional binding reactions are quantitated. The implications of this multivalency for the functions of NC in virus replication are discussed.

A high-throughput screen for identification of molecular mimics of Smac/DIABLO utilizing a fluorescence polarization assay.

Resistance to apoptosis is afforded by inhibitor of apoptosis proteins (IAPs) which bind to and inhibit the caspases responsible for cleavage of substrates leading to apoptotic cell death. Smac (or DIABLO), a proapoptotic protein released from the mitochondrial intermembrane space into the cytosol, promotes apoptosis by binding to IAPs, thus reversing their inhibitory effects on caspases. We have developed a high-throughput fluorescence polarization assay utilizing a fluorescein-labeled peptide similar to the "IAP binding" domain of Smac N terminus complexed with the BIR3 domain of X-linked IAP (XIAP) to identify small-molecule mimics of the action of Smac. The IC(50)s of peptides and a tetrapeptidomimetic homologous to the N terminus of Smac demonstrated the specificity and utility of this assay. We have screened the National Cancer Institute "Training Set" of 230 compounds, with well-defined biological actions, and the "Diversity Set" of 2000 chemically diverse structures for compounds which significantly reduced fluorescence polarization. Highly fluorescing or fluorescence-quenching compounds (false positives) were distinguished from those which interfered with Smac peptide binding to the XIAP-BIR3 in a dose-dependent manner (true positives). This robust assay offers potential for high-throughput screening discovery of novel compounds simulating the action of Smac/DIABLO.