Frequently Interrupting Prolonged Sitting With Light Body-Weighted Resistance Activity Alters Psychobiological Responses to Acute Psychological Stress: A Randomized Crossover Trial.

BACKGROUND: Uninterrupted prolonged sitting and exaggerated psychobiological reactivity to acute psychological stress are associated with increased risk of cardiovascular disease (CVD). Breaking up prolonged sitting with frequent, short bouts of light-intensity physical activity acutely lowers CVD risk markers under resting conditions. PURPOSE: To examine whether frequent interruptions to prolonged sitting with body-weighted resistance activity can acutely lower systolic blood pressure (SBP; primary outcome) and other cardiovascular (CV), inflammatory, and cortisol (secondary outcomes) responses to acute psychological stress. METHODS: This randomized crossover trial included 17 sedentary participants (9 men; mean ± SD age; 24.0 ± 0.5 years) who completed two conditions: (i) interrupting 4 hr of sitting with 4 min of light body-weighted resistance activity every 30-min (BREAK), and (ii) 4 hr of uninterrupted sitting (SIT). Following the BREAK and SIT intervention windows, CV, inflammatory, and cortisol markers were measured at rest, during stress tasks (8-min Paced Auditory Serial Addition Test [PASAT] and 3-min cold pressor [CP]), and 45-min recovery periods. RESULTS: There were main effects of time for CV parameters (SBP, diastolic blood pressure, heart rate, cardiac output, and total peripheral resistance [all p < .001]), inflammatory markers (interleukin-6 [IL-6]), and cortisol (p < .05) in response to stress. Time-by-condition interaction effects revealed that in the BREAK-condition there was lower SBP during immediate recovery from the CP (mean {95% confidence interval [CI]}: 127.2 [121.3, 133.4] vs 133.4 [125.5, 141.7] mmHg; p = .020), higher concentrations of plasma IL-6 45-min post-PASAT (2.70 [1.97, 3.70] vs 1.71 [1.32, 2.22] pg/mL; p = .010), and larger (nonsignificant) salivary cortisol concentrations 8-min post-CP (6.29 [4.60, 8.58] vs 3.97 [3.16, 4.99] nmol/L; p = .079). CONCLUSIONS: Interrupting prolonged sitting with frequent bouts of light intensity body-weighted resistance activity alters psychobiological responses to acute psychological stress. Further research should explore the longer-term implications for CVD risk.

Sitting for long periods without interruption and the way in which we physically respond to short-term psychological stress are linked to heart disease risk. Breaking up sitting with short, frequent bouts of light activity can lower heart disease risk but how this may improve how we respond to stress is unknown. Our study investigated if interruptions to prolonged sitting with body-weighted resistance activity lowered changes seen under stress such as changes in blood pressure (BP) and inflammation. Seventeen participants undertook two testing sessions. One session interrupted 4 hr of sitting with 4-min of light activity every 30-min, and the other session was 4 hr of uninterrupted sitting. After each session, participants did two stress tasks: one math-based task and one where feet were submerged in cold water. The changes in BP and inflammation to stress were measured. We found when breaking-up sitting time with activity, BP was lower after the cold-water task compared to when people did not break up their sitting. In summary, breaking up sitting with frequent bouts of light activity may influence how we respond to short-term stress, but future research needs to explore what these short-term changes mean for the longer-term risks of heart disease.

The structured health intervention for truckers (SHIFT) cluster randomised controlled trial: a mixed methods process evaluation.

BACKGROUND: This paper presents the mixed methods process evaluation of the randomised controlled trial (RCT) of the Structured Health Intervention For Truckers (SHIFT), a multi-component intervention targeting physical activity and positive lifestyle behaviours in a cohort of 382 truck drivers in the UK. The SHIFT RCT found a significant difference in daily steps between intervention and control groups at 6-months in favour of the intervention participants. METHODS: SHIFT was evaluated within a cluster-RCT and involved 25 transport sites (12 intervention and 13 control sites). Intervention components included an education session, Fitbit, text messages, and cab workout equipment. Participants completed questionnaires at baseline and 6-months follow-up. Semi-structured focus groups/interviews were conducted with drivers (n = 19) and managers (n = 18) from each site, after completion of the final follow-up health assessment (16-18 months post-randomisation). Questionnaires and interviews collected information on fidelity, dose, context, implementation, barriers, sustainability, and contamination. RESULTS: Questionnaire and interview data from intervention participants indicated favourable attitudes towards SHIFT, specifically towards the Fitbit with a high proportion of drivers reporting regularly using it (89.1%). 79.2% of intervention participants attended the education session, which was deemed useful for facilitating improvements in knowledge and behaviour change, dietary changes were predominantly recalled. Despite not being part of the intervention, participants reported that feedback from the health assessments motivated them to change aspects of their lifestyle (intervention = 91.1%, control = 67.5%). The cab workout equipment was used less and spoken unfavourably of in the interviews. The main barriers to a healthy lifestyle at work were reported as long hours and irregular shift patterns. The most suggested improvement for the intervention was more frequent contact with drivers. Managers were positive about the objectives of SHIFT, however almost all mentioned the challenges related to implementation, specifically in smaller sites. CONCLUSIONS: Overall, SHIFT was predominantly implemented as intended, with minimal discrepancies seen between the delivery and protocol. Having said this, transport sites each have distinct characteristics, which may require adaptations to individual settings to encourage participation. Managers and drivers reported enthusiasm and necessity for SHIFT to be included in future Certificate of Professional Competence training. TRIAL REGISTRATION: ISRCTN10483894 (date registered: 01/03/2017).

Sedentary behaviour is associated with heightened cardiovascular, inflammatory and cortisol reactivity to acute psychological stress.

BACKGROUND: Sedentary behaviour is a risk factor for cardiovascular disease (CVD), but the underlying mechanisms remain unclear. Exaggerated psychobiological responses to acute psychological stress increase CVD risk. Sedentary behaviour is associated with characteristics that can predict large psychobiological stress response patterns (e.g., elevated resting blood pressure and systemic inflammation), but it is currently unknown whether sedentary behaviour and stress reactivity are directly linked. The aim of this study was to examine associations between device-assessed sedentary behaviour and measures of stress reactivity. METHODS: Sixty-one healthy adults wore an activPAL (thigh) and ActiGraph (wrist) for seven days to measure habitual levels of sedentary behaviour (mean ± SD = 9.96 ± 1.48 h/day) and moderate-to-vigorous physical activity (mean ± SD = 101.82 ± 42.92 min/day). Participants then underwent stress reactivity testing, where beat-to-beat cardiovascular (e.g., blood pressure, total peripheral resistance), inflammatory (plasma interleukin-6, leukocytes) and salivary cortisol measurements were taken in response to an 8-minute socially evaluative Paced Auditory Serial Addition Test. RESULTS: Higher volumes of daily sedentary behaviour were associated with larger stress responses for diastolic blood pressure (Β=1.264, 95%CI=0.537-1.990, p = .005), total peripheral resistance (Β=40.563, 95%CI=19.310-61.812, p < .001), interleukin-6 (Β=0.219, 95%CI=0.109-0.329, p < .001) and cortisol (Β=1.844, 95%CI=1.139-2.549, p < .001). These findings emerged independent of a priori determined covariates, including daily levels of moderate-to-vigorous physical activity and adiposity. DISCUSSION: Exaggerated stress reactivity is characteristic of high sedentary behaviour and could be a novel mechanism linking sedentary behaviour with CVD. Future work should examine the impact of reducing sedentary behaviour on measures of stress reactivity, as this may have clinical relevance for preventing CVD.

Cardiometabolic risk factors and mental health status among truck drivers: a systematic review.

OBJECTIVE: This study aimed to systematically review and summarise the literature on cardiometabolic risk factors, lifestyle health behaviours and mental health status of truck drivers globally to ascertain the scale of these health concerns. DESIGN: Systematic review reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: PubMed, Scopus, PsycINFO and Web of Science were searched in January 2019 and updated in January 2020, from the date of inception to 16 January 2020. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Papers were included if they (1) reported independent data on truck drivers, (2) included quantitative data on outcomes related to cardiometabolic markers of health, mental health and/or health behaviours, (3) were written in English and (4) were published in a peer-reviewed journal. Grey literature was ineligible for this review. DATA EXTRACTION AND SYNTHESIS: One reviewer independently extracted data and assessed methodological quality using a checklist based on the National Heart, Lung and Blood Institute Quality Assessment tool. 20% were independently assessed for eligibility and quality by a second reviewer. Due to heterogeneity of the outcomes, results were narratively presented. RESULTS: 3601 titles and abstracts were screened. Seventy-three studies met the inclusion criteria. Truck driving is associated with enforced sedentarism, long and irregular working hours, lack of healthy foods, social isolation and chronic time pressures. Strong evidence was observed for truck drivers to generally exhibit poor cardiometabolic risk profiles including overweight and obesity, hypertension, hypercholesterolaemia, high blood glucose, poor mental health and cigarette smoking. CONCLUSIONS: Improving truck driver health is vital for the longevity of the trucking industry, and for the safety of all road users. The workplace plays a vital role in truck driver health; policies, regulations and procedures are required to address this health crisis. PROSPERO REGISTRATION NUMBER: CRD42019124499.

Psychological distress is related to poor health behaviours in COPD and non-COPD patients: Evidence from the CanCOLD study.

BACKGROUND: Patients with psychiatric disorders (depression, anxiety) are more likely to have poor health behaviours, including higher smoking and lower physical activity (PA) levels. Smoking is a major risk factor for Chronic Obstructive Pulmonary Disease (COPD), and PA is critical for COPD management. However, no studies have assessed associations between psychological distress and these behaviours among patients with vs without COPD. This is a sub-analysis of the CanCOLD study that assessed the relationships between psychological disorders (depression, anxiety) and poor health behaviours (smoking, PA). METHODS: 717 COPD and 797 matched non-COPD individuals from the CanCOLD study, completed the Hospital Anxiety Depression Scale (HADS) to assess anxiety and depression. Smoking behaviour was self-reported pack-years smoking. The CHAMPS PA questionnaire determined calorific expenditure as a PA measure. Regressions determined relationships between anxiety/depression and health behaviours, adjusting for age, sex, BMI, GOLD stage and COPD status. RESULTS: Across the whole sample, we observed relationships between depression (ß = 1.107 ±â€¯0.197; 95%CI = 0.691-1.462; p < .001) and anxiety (ß = 0.780 ±â€¯0.170; 95%CI = 0.446-1.114; p < .001) and pack years. Higher depression (ß = -0.220 ±â€¯0.028; 95%CI = -0.275 to -0.165; p < .001) and anxiety (ß = -0.091 ±â€¯0.025; 95%CI = -0.139 to -0.043; p < .001) scores were related to lower PA. These associations were comparable across COPD and non-COPD patients. CONCLUSIONS: Results showed that higher levels of anxiety and depression were related to higher cumulative smoking and lower levels of PA in patients with and without COPD, suggesting symptoms of psychological distress is similarly associated with poorer health behaviours in COPD and non-COPD individuals. Future studies need to determine if treating symptoms of psychological distress can improve health behaviours and outcomes in this population.

Association of depressive and anxiety symptoms with 24-hour urinary catecholamines in individuals with untreated high blood pressure.

OBJECTIVE: Depression and anxiety are considered risk factors for cardiovascular disease (CVD). The explanatory mechanisms, however, are still to be characterized. One proposed pathophysiological pathway is dysregulation of the autonomic nervous system, including heightened sympathetic nervous system activity. This study examined the relationship between symptoms of depression, anxiety, and sympathetic nervous system activity in individuals with untreated high blood pressure. METHODS: A total of 140 participants with untreated high blood pressure (55% white, 38.5% female, mean [standard deviation] age = 45.5 [8.55] years) collected urine over a 24-hour period on 3 separate occasions. Urine samples were assayed for mean 24-hour epinephrine (EPI24) and norepinephrine excretion. Depressive symptoms were assessed using the Beck Depression Inventory, with anxiety symptoms assessed using the Spielberger State-Trait Anxiety Inventory. RESULTS: Depression and anxiety scores were intercorrelated (r = 0.76, p < .001). EPI24 was positively correlated with anxiety (r = 0.20, p = .02) but not depression (r = 0.02, p = .77), whereas 24-hour urinary norepinephrine excretion was not correlated with anxiety (r = 0.10, p = .21) or with depression (r = 0.07, p = .39). Regression models, accounting for sex, age, body mass index, race, mean systolic ambulatory blood pressure, tobacco use, alcohol use, physical activity, and sleep efficiency confirmed that anxiety was associated with EPI24 excretion (p = .023) and that depressive symptoms were not (p = .54). CONCLUSIONS: Anxiety was associated with heightened sympathoadrenal activity, suggesting a biological pathway through which anxiety could increase CVD risk. Anxiety and depression may confer increased CVD risk via different mechanisms.

Induced mild systemic inflammation is associated with impaired ability to improve cognitive task performance by practice.

Elevated inflammatory levels are linked to poorer cognition, but experimental confirmation is lacking. This report examined associations between cognitive performance and inflammation induced by exercise and vaccination. Thirty-six (exercise N = 18, vaccination N = 18) healthy males completed a paced auditory serial addition test (PASAT), which is a multifaceted measure of cognitive function. The task was completed in placebo and elevated inflammation states. Improvements in PASAT performance were related to inflammation. In the exercise study, IL-6 during the first PASAT negatively correlated with PASAT improvement (p = .022). In the vaccination study, increases in C-reactive protein between PASATs correlated with reduced PASAT improvement (p < .001). Inflammation was linked to reduced improvements in cognitive performance. Further research should identify the specific cognitive functions affects and the underlying mechanisms.

Vaccine-induced inflammation attenuates the vascular responses to mental stress.

Inflammation is associated with poorer vascular function, with evidence to suggest that inflammation can also impair the vascular responses to mental stress. This study examined the effects of vaccine-induced inflammation on vascular responses to mental stress in healthy participants. Eighteen male participants completed two stress sessions: an inflammation condition having received a typhoid vaccination and a control (non-inflamed) condition. Tumor necrosis factor-alpha and interleukin-6 (p's<.001) increased following vaccination, confirming modest increases in inflammation. Mental stress increased blood flow, blood pressure, heart rate, and cardiac output in both conditions (all p's<.001), but the blood flow response to stress was attenuated having received the vaccination compared to the control condition (p's<.05). These results further implicate the interaction between inflammation and the vasculature as a mechanism through which stress may trigger myocardial infarction.

Underlying inflammation has no impact on the oxidative stress response to acute mental stress.

INTRODUCTION: Mental stress is considered to be a trigger for acute myocardial infarction (MI), with inflammation thought to provide a mechanism. Inflammation is reciprocally linked to oxidative stress, which has also been implicated in MI. The purpose of this study was to assess the effects of experimentally-induced inflammation on the oxidative stress response to mental stress in healthy participants. METHODS: Healthy males undertook one of two inflammatory stimuli: typhoid vaccination (Vaccination paradigm, N=17) or eccentric exercise (Eccentric exercise paradigm, N=17). All participants completed a mental arithmetic stress task twice (within-subject design): 6h after the inflammatory stimulus, and during a control non-inflammation condition. Blood samples were taken before, immediately and 30min after the stress task. Plasma was assessed for interleukin-6 (IL-6), protein carbonyls (PC), lipid hydroperoxides (LOOH), total antioxidant capacity (TAC) and nitric oxide metabolites (NOx). RESULTS: Vaccination paradigm: IL-6, PC and NOx were significantly higher in the vaccination condition, relative to the control condition (p<.05). PC, TAC, LOOH and NOx were unchanged in response to mental stress in both the vaccination and control conditions. Eccentric Exercise paradigm: IL-6 and TAC were significantly higher in the eccentric exercise condition (p<.05), relative to the control condition. PC, TAC and NOx were unchanged in response to mental stress in both the eccentric exercise and control conditions. CONCLUSIONS: Two different inflammatory paradigms were successful in increasing selective plasma markers of inflammation and oxidative stress prior to a mental stress task. However, experimentally induced transient inflammation had no impact on mental stress-induced changes in plasma LOOH, PC, TAC or NOx in young healthy participants.

The time course of the inflammatory response to the Salmonella typhi vaccination.

The Salmonella typhi vaccination induces transient increases in inflammatory-responsive cytokines and molecules. For instance, it causes small, mild increases in interleukin-6 (IL-6) within a few hours and C-reactive protein (CRP) within 24h. No study has charted either the time course of the inflammatory response to this vaccine or any associated changes in mood, physical symptoms, and cardiac function. In a blinded crossover experimental design, eight participants received the S. typhi vaccine (vaccination condition) and a saline (control condition) injection on two separate days, at least one week apart. Blood samples and mood ratings were collected at 0, 4, 5, 6, 7, 8 and 24h post-injection, physical symptoms and pain were assessed at 4-8 and 24h post-injection, and cardiovascular function was recorded until 8h post-injection. Repeated measures analyses of variance and polynomial trend analyses compared the timecourse of the response patterns between the two conditions. Whereas there were no temporal changes in the control condition, the vaccination increased granulocytes, IL-6, TNF-α, and CRP (all p's<.05). Specifically, the granulocytes, IL-6 and TNF-α peaked after 6-8h while CRP peaked after 24h. This vaccine-induced mild inflammatory response was not accompanied by any changes in mood or cardiovascular activity. We also found that participants tended to report more pain in the injected limb in the vaccination condition (p<.07). In sum, our study charted the timecourse of key inflammatory-responsive markers following S. typhi vaccination and identified the timing of their modest peaks. It is worth noting that changes in these markers were not accompanied by any notable changes in mood or cardiovascular activity, and thus the S. typhi vaccination is a suitable method to induce increases in inflammatory-responsive markers, without altering mood or cardiovascular parameters.