Greater hepatic lipid saturation is associated with impaired glycaemic regulation in men with metabolic dysfunction-associated steatotic liver disease but is not altered by 6 weeks of exercise training.

AIMS: To examine the impact of impaired glycaemic regulation (IGR) and exercise training on hepatic lipid composition in men with metabolic dysfunction-associated steatotic liver disease (MASLD). MATERIALS AND METHODS: In Part A (cross-sectional design), 40 men with MASLD (liver proton density fat fraction [PDFF] ≥5.56%) were recruited to one of two groups: (1) normal glycaemic regulation (NGR) group (glycated haemoglobin [HbA1c] < 42 mmol∙mol-1 [<6.0%]; n = 14) or (2) IGR group (HbA1c ≥ 42 mmol∙mol-1 [≥6.0%]; n = 26). In Part B (randomized controlled trial design), participants in the IGR group were randomized to one of two 6-week interventions: (1) exercise training (EX; 70%-75% maximum heart rate; four sessions/week; n = 13) or (2) non-exercise control (CON; n = 13). Saturated (SI; primary outcome), unsaturated (UI) and polyunsaturated (PUI) hepatic lipid indices were determined using proton magnetic resonance spectroscopy. Additional secondary outcomes included liver PDFF, HbA1c, fasting plasma glucose (FPG), homeostatic model assessment of insulin resistance (HOMA-IR), peak oxygen uptake (VO2 peak), and plasma cytokeratin-18 (CK18) M65, among others. RESULTS: In Part A, hepatic SI was higher and hepatic UI was lower in the IGR versus the NGR group (p = 0.038), and this hepatic lipid profile was associated with higher HbA1c levels, FPG levels, HOMA-IR and plasma CK18 M65 levels (rs ≥0.320). In Part B, hepatic lipid composition and liver PDFF were unchanged after EX versus CON (p ≥ 0.257), while FPG was reduced and VO2 peak was increased (p ≤ 0.030). ΔVO2 peak was inversely associated with Δhepatic SI (r = -0.433) and positively associated with Δhepatic UI and Δhepatic PUI (r ≥ 0.433). CONCLUSIONS: Impaired glycaemic regulation in MASLD is characterized by greater hepatic lipid saturation; however, this composition is not altered by 6 weeks of moderate-intensity exercise training.

An acute bout of swimming increases post-exercise energy intake in young healthy men and women.

Single bouts of land-based exercise (for example, walking, running, cycling) do not typically alter post-exercise energy intake on the day of exercise. However, anecdotal and preliminary empirical evidence suggests that swimming may increase appetite and energy intake. This study compared the acute effects of swimming on appetite, energy intake, and food preference and reward, versus exertion-matched cycling and a resting control. Thirty-two men (n = 17; mean ± SD age 24 ± 2 years, body mass index [BMI] 25.0 ± 2.6 kg/m2) and women (n = 15; age 22 ± 3 years, BMI 22.8 ± 2.3 kg/m2) completed three experimental trials (swimming, cycling, control) in a randomised, crossover design. The exercise trials involved 60-min of 'hard' exercise (self-selected rating of perceived exertion: 15) performed 90-min after a standardised breakfast. Food preference and reward were assessed via the Leeds Food Preference Questionnaire 15-min after exercise, whilst ad libitum energy intake was determined 30-min after exercise. The control trial involved identical procedures except no exercise was performed. Compared with control (3259 ± 1265 kJ), swimming increased ad libitum energy intake (3857 ± 1611 kJ; ES = 0.47, 95% CI of the mean difference between trials 185, 1010 kJ, P = 0.005); the magnitude of increase was smaller after cycling (3652 ± 1619 kJ; ES = 0.31, 95% CI -21, 805 kJ, P = 0.062). Ad libitum energy intake was similar between swimming and cycling (ES = 0.16, 95% CI -207, 618 kJ, P = 0.324). This effect was consistent across sexes and unrelated to food preference and reward which were similar after swimming and cycling compared with control. This study has identified an orexigenic effect of swimming. Further research is needed to identify the responsible mechanism(s), including the relevance of water immersion and water temperature per se.

activPAL-measured sitting levels and patterns in 9-10 years old children from a UK city.

BACKGROUND: There is insufficient evidence of sitting time in UK children from validated objective measures. This study explored sitting patterns in primary school children from Bradford, UK, using the validated activPAL inclinometer. METHODS: Overall, 79 children (9.8 (SD 0.3) years old, 52% boys; 70% South Asian) wore activPALs for 7 days. Total sitting time, sitting time accumulated in different bout lengths, and the proportion of wear time spent in these variables were explored and compared across different periods of the week. RESULTS: Children spent 614 ± 112 (median ± IQR) min/day on school days and 690 ± 150 min/day on weekend days sitting. The proportion of time spent sitting was significantly higher on weekend days compared to school days (mean±SD: 74 ± 10% versus 68 ± 8%,P < 0.001), as was the proportion of time accumulated in >30 min sitting bouts (mean±CI: 28 ± 27-33% versus 20 ± 20-22%, P < 0.001). The proportion of time spent sitting after school was significantly higher than during school time (mean±SD: 70 ± 8.4% versus 63 ± 8.3%,P < 0.001), as was the proportion of time spent in prolonged (>30 min) sitting bouts (mean±CI: 19 ± 16-22% versus 11 ± 10-14%, P < 0.001). CONCLUSIONS: Children spent large proportions of their waking day sitting, often accumulated in prolonged uninterrupted bouts and particularly after school and on weekends. Interventions to reduce sitting time in children are urgently needed.

Physical activity is inversely associated with hepatic fibro-inflammation: A population-based cohort study using UK Biobank data.

Background & Aims: Physical activity (PA) is recommended in the management of non-alcoholic fatty liver disease (NAFLD) given its beneficial effects on liver fat and cardiometabolic risk. Using data from the UK Biobank population-cohort, this study examined associations between habitual PA and hepatic fibro-inflammation. Methods: A total of 840 men and women aged 55-70 years were included in this cross-sectional study. Hepatic fibro-inflammation (iron-corrected T1 [cT1]) and liver fat were measured using MRI, whilst body fat was measured using dual-energy X-ray absorptiometry. PA was measured using accelerometry. Generalised linear models examined associations between PA (light [LPA], moderate [MPA], vigorous [VPA], moderate-to-vigorous [MVPA] and mean acceleration) and hepatic cT1. Models were fitted for the whole sample and separately for upper and lower median groups for body and liver fat. Models were adjusted for sociodemographic and lifestyle variables. Results: In the full sample, LPA (-0.08 ms [-0.12 to -0.03]), MPA, (-0.13 ms [-0.21 to -0.05]), VPA (-1.16 ms [-1.81 to -0.51]), MVPA (-0.14 ms [-0.21 to -0.06]) and mean acceleration (-0.67 ms [-1.05 to-0.28]) were inversely associated with hepatic cT1. With the sample split by median liver or body fat, only VPA was inversely associated with hepatic cT1 in the upper median groups for body (-2.68 ms [-4.24 to -1.13]) and liver fat (-2.33 [-3.73 to -0.93]). PA was unrelated to hepatic cT1 in the lower median groups. Conclusions: Within a population-based cohort, device-measured PA is inversely associated with hepatic fibro-inflammation. This relationship is strongest with VPA and is greater in people with higher levels of body and liver fat. Lay summary: This study has shown that people who regularly perform greater amounts of physical activity have a reduced level of inflammation and fibrosis in their liver. This beneficial relationship is particularly strong when more intense physical activity is undertaken (i.e., vigorous-intensity), and is most visible in individuals with higher levels of liver fat and body fat.

Physical Activity, Sedentary Time, and Cardiometabolic Health in Heavy Goods Vehicle Drivers.

OBJECTIVE: Physical inactivity, prolonged sitting, and unhealthy dietary habits are common in Heavy Goods Vehicle (HGV) drivers. These factors increase risk of long-term health conditions. METHODS: 329 HGV drivers across 25 UK depots completed a health assessment, including questionnaire completion, and objectively measured anthropometrics, blood biomarkers, physical activity (PA), and sedentary behavior. RESULTS: The sample demonstrated a high-risk cardiometabolic health profile. 88.1% were overweight or had obesity, and 11.9% had pre-diabetes or diabetes. 28.3% had hypertension, 83.6% had clinically elevated circulating low-density lipoprotein-cholesterol concentrations (>2mmol/l), and 66.6% had high total cholesterol levels (>4mmol/l). On workdays drivers accumulated 12 hours/day of sitting, 1.7 hours/day of light PA, and 9.8 mins/day of moderate-to-vigorous PA. Associations between light PA and cardiometabolic markers were observed. CONCLUSION: This sample presents high levels of inactivity, overweight, and obesity, and unhealthy cardiometabolic health profiles.

Drivers with and without Obesity Respond Differently to a Multi-Component Health Intervention in Heavy Goods Vehicle Drivers.

Physical inactivity and obesity are widely prevalent in Heavy Goods Vehicle (HGV) drivers. We analysed whether obesity classification influenced the effectiveness of a bespoke structured lifestyle intervention ('SHIFT') for HGV drivers. The SHIFT programme was evaluated within a cluster randomised controlled trial, across 25 transport depots in the UK. After baseline assessments, participants within intervention sites received a 6-month multi-component health behaviour change intervention. Intervention responses (verses control) were stratified by obesity status (BMI < 30 kg/m2, n = 131; BMI ≥ 30 kg/m2, n = 113) and compared using generalised estimating equations. At 6-months, favourable differences were found in daily steps (adjusted mean difference 1827 steps/day, p < 0.001) and sedentary time (adjusted mean difference -57 min/day, p < 0.001) in drivers with obesity undertaking the intervention, relative to controls with obesity. Similarly, in drivers with obesity, the intervention reduced body weight (adjusted mean difference -2.37 kg, p = 0.002) and led to other favourable anthropometric outcomes, verses controls with obesity. Intervention effects were absent for drivers without obesity, and for all drivers at 16-18-months follow-up. Obesity classification influenced HGV drivers' behavioural responses to a multi-component health-behaviour change intervention. Therefore, the most at-risk commercial drivers appear receptive to a health promotion programme.

Time in Nature Associated with Decreased Fatigue in UK Truck Drivers.

Heavy goods vehicle (HGV) driving is recognised as a highly hazardous occupation due to the long periods of sedentary behaviour, low levels of physical activity and unhealthy food options when working. These risk factors combine with shift work and concomitant irregular sleep patterns to increase the prevalence of fatigue. Fatigue is closely linked with stress and, subsequently, poor physiological and psychological health. In parallel, a wealth of evidence has demonstrated the health and wellbeing benefits of spending time in nature. Here, we sought to examine whether spending time in nature was associated with lower levels of fatigue, anxiety and depression in HGV drivers. 89 long-distance drivers (98.9% male, mean ± SD age: 51.0 ± 9 years, body mass index: 29.8 ± 4.7 kg/m2) participating in a wider health promotion programme reported time spent in nature (during and before the Covid-19 pandemic) and symptoms of occupational fatigue, depression and anxiety. After controlling for covariates, truck drivers who visited nature at least once a week exhibited 16% less chronic fatigue prior to the pandemic, and 23% less chronic fatigue and 20% less acute fatigue during the pandemic. No significant differences were observed for either anxiety or depression. As fatigue has a range of physical and mental health sequelae, we propose that increased exposure to natural settings may make a valuable contribution to interventions to promote the health and wellbeing of this underserved group.

Impacts of a Standing Desk Intervention within an English Primary School Classroom: A Pilot Controlled Trial.

Traditional classroom furniture dictates that children predominantly sit during class time. This study evaluated the impact of providing standing desks within a deprived UK primary school setting over 8 months using mixed-method approaches. All children within a Year 5 class (9-10-year-olds, n = 30) received an adjustable sit-stand desk, while another Year 5 class (n = 30) in a nearby school retained traditional furniture as a control classroom. At baseline, 4 months, and 8 months, activPAL monitors (PAL Technologies, Glasgow, UK) were worn for 7 days to provide time spent sitting and standing. Behavior-related mental health, musculoskeletal discomfort surveys, and a cognitive function test battery were also completed at all three timepoints. Intervention experiences from pupils and the teacher were captured using focus groups, interviews, and classroom observations. At both 4 months and 8 months, multi-level models revealed a reduction in class time sitting in the intervention group compared to the control group ((ß (95%CI) 4 months -25.3% (-32.3, -18.4); 8 months -19.9% (-27.05, -12.9)). Qualitative data revealed challenges to teaching practicalities and a gradual decline in behavior-related mental health was observed (intervention vs. control: 4 months +5.31 (+2.55, +8.08); 8 months +7.92 (+5.18, +10.66)). Larger trials within similar high-priority settings are required to determine the feasibility and cost-effectiveness of providing standing desks to every child in the classroom.

The effects of standing desks within the school classroom: A systematic review.

BACKGROUND: The school classroom environment often dictates that pupils sit for prolonged periods which may be detrimental for children's health. Replacing traditional school desks with standing desks may reduce sitting time and provide other benefits. The aim of this systematic review was to assess the impact of standing desks within the school classroom. METHOD: Studies published in English up to and including June 2015 were located from online databases and manual searches. Studies implementing standing desks within the school classroom, including children and/or adolescents (aged 5-18 years) which assessed the impact of the intervention using a comparison group or pre-post design were included. RESULTS: Eleven studies were eligible for inclusion; all were set in primary/elementary schools, and most were conducted in the USA (n = 6). Most were non-randomised controlled trials (n = 7), with durations ranging from a single time point to five months. Energy expenditure (measured over 2 h during school day mornings) was the only outcome that consistently demonstrated positive results (three out of three studies). Evidence for the impact of standing desks on sitting, standing, and step counts was mixed. Evidence suggested that implementing standing desks in the classroom environment appears to be feasible, and not detrimental to learning. CONCLUSIONS: Interventions utilising standing desks in classrooms demonstrate positive effects in some key outcomes but the evidence lacks sufficient quality and depth to make strong conclusions. Future studies using randomised control trial designs with larger samples, longer durations, with sitting, standing time and academic achievement as primary outcomes, are warranted.