Zeljko Pedisic

Are Sitting Occupations Associated with Increased All- Cause, Cancer, and Cardiovascular Disease Mortality Risk? A Pooled Analysis of Seven British Population Cohorts

Background There is mounting evidence for associations between sedentary behaviours and adverse health outcomes, although the data on occupational sitting and mortality risk remain equivocal. The aim of this study was to determine the association between occupational sitting and cardiovascular, cancer and all-cause mortality in a pooled sample of seven British general population cohorts. Methods The sample comprised 5380 women and 5788 men in employment who were drawn from five Health Survey for England and two Scottish Health Survey cohorts. Participants were classified as reporting standing, walking or sitting in their work time and followed up over 12.9 years for mortality. Data were modelled using Cox proportional hazard regression adjusted for age, waist circumference, self-reported general health, frequency of alcohol intake, cigarette smoking, non-occupational physical activity, prevalent cardiovascular disease and cancer at baseline, psychological health, social class, and education. Results In total there were 754 all-cause deaths. In women, a standing/walking occupation was associated with lower risk of all-cause (fully adjusted hazard ratio [HR] = 0.68, 95% CI 0.52–0.89) and cancer (HR = 0.60, 95% CI 0.43–0.85) mortality, compared to sitting occupations. There were no associations in men. In analyses with combined occupational type and leisure-time physical activity, the risk of all-cause mortality was lowest in participants with non-sitting occupations and high leisure-time activity. Conclusions Sitting occupations are linked to increased risk for all-cause and cancer mortality in women only, but no such associations exist for cardiovascular mortality in men or women.

Age- and Sex-Specific Criterion Validity of the Health Survey for England Physical Activity and Sedentary Behavior Assessment Questionnaire as Compared With Accelerometry

The criterion validity of the 2008 Physical Activity and Sedentary Behavior Assessment Questionnaire (PASBAQ) was examined in a nationally representative sample of 2,175 persons aged ≥16 years in England using accelerometry. Using accelerometer minutes/day greater than or equal to 200 counts as a criterion, Spearmans correlation coefficient (ρ) for PASBAQ-assessed total activity was 0.30 (95% confidence interval (CI): 0.25, 0.35) in women and 0.20 (95% CI: 0.15, 0.26) in men. Correlations between accelerometer counts/minute of wear time and questionnaire-assessed relative energy expenditure (metabolic equivalent-minutes/day) were higher in women (ρ = 0.41, 95% CI: 0.36, 0.46) than in men (ρ = 0.32, 95% CI: 0.26, 0.38). Similar correlations were observed for minutes/day spent in vigorous activity (women: ρ = 0.39, 95% CI: 0.33, 0.46; men: ρ = 0.31, 95% CI: 0.26, 0.36) and moderate-to-vigorous activity (women: ρ = 0.42, 95% CI: 0.36, 0.48; men: ρ = 0.38, 95% CI: 0.32, 0.45). Correlations for time spent being sedentary (<100 counts/minute) were 0.30 (95% CI: 0.24, 0.35) and 0.25 (95% CI: 0.19, 0.30) in women and men, respectively. Sedentary behavior correlations showed no sex difference. The validity of sedentary behavior and total physical activity was higher in older age groups, but validity was higher in younger persons for vigorous-intensity activity. The PASBAQ is a useful and valid instrument for ranking individuals according to levels of physical activity and sedentary behavior.

High sitting time or obesity: Which came first? Bidirectional association in a longitudinal study of 31,787 Australian adults

Evidence on the direction of the association between sitting time and obesity is limited. The prospective associations between baseline total sitting time and subsequent changes in body mass index (BMI), and baseline BMI and subsequent changes in sitting time were examined.

Total and domain-specific sitting time among employees in desk-based work settings in Australia

Objective: To describe the total and domain‐specific daily sitting time among a sample of Australian office‐based employees.

Associations of specific types of sports and exercise with all-cause and cardiovascular-disease mortality: A cohort study of 80,306 British adults

Background/Aim Evidence for the long-term health effects of specific sport disciplines is scarce. Therefore, we examined the associations of six different types of sport/exercise with all-cause and cardiovascular disease (CVD) mortality risk in a large pooled Scottish and English population-based cohort. Methods Cox proportional hazards regression was used to investigate the associations between each exposure and all-cause and CVD mortality with adjustment for potential confounders in 80 306 individuals (54% women; mean±SD age: 52±14 years). Results Significant reductions in all-cause mortality were observed for participation in cycling (HR=0.85, 95% CI 0.76 to 0.95), swimming (HR=0.72, 95% CI 0.65 to 0.80), racquet sports (HR=0.53, 95% CI 0.40 to 0.69) and aerobics (HR=0.73, 95% CI 0.63 to 0.85). No significant associations were found for participation in football and running. A significant reduction in CVD mortality was observed for participation in swimming (HR=0.59, 95% CI 0.46 to 0.75), racquet sports (HR=0.44, 95% CI 0.24 to 0.83) and aerobics (HR=0.64, 95% CI 0.45 to 0.92), but there were no significant associations for cycling, running and football. Variable dose–response patterns between the exposure and the outcomes were found across the sport disciplines. Conclusions These findings demonstrate that participation in specific sports may have significant benefits for public health. Future research should aim to further strengthen the sport-specific epidemiological evidence base and understanding of how to promote greater sports participation.

The Impact of Obesity in the Workplace: a Review of Contributing Factors, Consequences and Potential Solutions

This narrative review summarized findings from previous reviews and the most recently published studies, regarding the following: (1) the association between two occupational risk factors—shift work and sedentary work—and obesity, (2) the effects of obesity on workplace productivity and (3) the effectiveness of workplace interventions aimed at preventing or reducing obesity. Despite some inconsistencies in findings, there is convincing evidence that shift work increases the risk of obesity, while most studies did not show a significant association between sedentary work and obesity. Overweight and obesity were found to be associated with absenteeism, disability pension and overall work impairment, whilst evidence of their relationship with presenteeism, unemployment and early retirement was not consistent. Due to the vast heterogeneity in the types of workplace-based interventions to prevent or treat obesity, no sound conclusions can as yet be drawn about their overall effectiveness and best practice recommendations for their implementation.

Effectiveness of interventions for reducing non-occupational sedentary behaviour in adults and older adults: a systematic review and meta-analysis

Background No systematic reviews of the effectiveness of interventions for reducing non-occupational sedentary behaviour are available. Therefore, the aim of this systematic review was to assess the effectiveness of interventions for reducing non-occupational sedentary behaviour in adults and older adults. Methods An electronic search of nine databases was performed. Randomised controlled trials (RCT) and cluster RCTs among adults testing the effectiveness of interventions aimed to reduce non-occupational sedentary behaviour were considered for inclusion. Two review authors independently screened studies for eligibility, completed data extraction and assessed the risk of bias. Results Nineteen studies that evaluated multicomponent lifestyle interventions, counselling or education, television (TV) control devices and workplace interventions were included. Evidence from the meta-analyses suggested that interventions can reduce leisure sitting time in adults in the medium term (−30 min/day; 95% CI −58 to –2), and TV viewing in the short term (−61 min/day; 95% CI −79 to –43) and medium term (−11 min/day; 95% CI −20 to –2). No significant pooled effects were found for transport sitting time, leisure-time computer use and longer term outcomes. No evidence was available on the effectiveness of interventions for reducing non-occupational sedentary time in older adults. Conclusions The findings of this systematic review suggest the interventions may be effective in reducing non-occupational sedentary behaviour in the short to medium term in adults. However, no significant effect was found on longer term outcomes. The quality of evidence was, however, low to very low. No evidence was available on the effectiveness of non-occupational interventions on reducing sedentary time in older adults. Further high-quality research with larger samples is warranted.

Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis

BackgroundCaffeine is commonly used as an ergogenic aid. Literature about the effects of caffeine ingestion on muscle strength and power is equivocal. The aim of this systematic review and meta-analysis was to summarize results from individual studies on the effects of caffeine intake on muscle strength and power.MethodsA search through eight databases was performed to find studies on the effects of caffeine on: (i) maximal muscle strength measured using 1 repetition maximum tests; and (ii) muscle power assessed by tests of vertical jump. Meta-analyses of standardized mean differences (SMD) between placebo and caffeine trials from individual studies were conducted using the random effects model.ResultsTen studies on the strength outcome and ten studies on the power outcome met the inclusion criteria for the meta-analyses. Caffeine ingestion improved both strength (SMD = 0.20; 95% confidence interval [CI]: 0.03, 0.36; p = 0.023) and power (SMD = 0.17; 95% CI: 0.00, 0.34; p = 0.047). A subgroup analysis indicated that caffeine significantly improves upper (SMD = 0.21; 95% CI: 0.02, 0.39; p = 0.026) but not lower body strength (SMD = 0.15; 95% CI: -0.05, 0.34; p = 0.147).ConclusionThe meta-analyses showed significant ergogenic effects of caffeine ingestion on maximal muscle strength of upper body and muscle power. Future studies should more rigorously control the effectiveness of blinding. Due to the paucity of evidence, additional findings are needed in the female population and using different forms of caffeine, such as gum and gel.

Workplace Sitting Breaks Questionnaire (SITBRQ): An assessment of concurrent validity and test-retest reliability

BackgroundBreaks in prolonged sitting may have beneficial cardiometabolic and musculoskeletal health outcomes. Desk-based work settings are an important environment to promote and support breaks in sitting time. However, few studies have reported the psychometric properties of self-report measures to assess the frequency and duration of breaks from sitting. This study examined the concurrent validity and test-retest reliability of the Workplace Sitting Breaks Questionnaire (SITBRQ) designed to assess frequency and duration of breaks in sitting within desk-based work settings.MethodsTo assess the concurrent validity, a sample of 147 desk-based employees completed the SITBRQ and wore an Actigraph GT1M accelerometer for seven consecutive days. To establish test-retest reliability, SITBRQ was administered on two separate occasions 7–14 days apart to a separate sample of 96 desk-based employees.ResultsA low relative agreement with accelerometry (Spearman’s r = 0.24 [95% CI 0.07 - 0.40]) was determined for self-reported frequency, but not for the duration of sitting breaks (Spearman’s r = 0.05 [95% CI −0.12 - 0.22]). Adequate reliability was determined for both self-reported frequency (Spearman’s r = 0.71 [95% CI 0.59 - 0.79], Cohen’s kappa = 0.74 [95% CI 0.64 - 0.84]) and duration of sitting breaks (Spearman’s r = 0.59 [95% CI 0.45 - 0.71], Cohen’s kappa = 0.61 [95% CI 0.38 - 0.85]).ConclusionSITBRQ may be used for assessment of the frequency of sitting breaks within desk-based work settings with validity and reliability similar to other self-reports in the field of sedentary behaviour research. However, until adequately improved and re-evaluated, it should not be used to collect data about the duration of breaks in sitting time.

Self-reported health-enhancing physical activity recommendation adherence among 64,380 finnish adults

The Finnish recommendations for health‐enhancing physical activity (PA) for adults (≥18 years) recommend: (i) ≥150 minutes of moderate‐to‐vigorous‐intensity physical activity (MVPA) and (ii) activities that develop muscle strength and balance ≥2 days/week. However, adherence to these recommendations among the Finnish adults is currently unknown. This study reports on the self‐reported adherence to the PA recommendations and associations with sociodemographic factors among Finnish adults. Data were used from the Finnish “Regional Health and Well‐being Study.” In 2013‐2014, postal questionnaires were sent to 132,560 persons, with 69,032 responding (response rate =52.1%). The weighted proportions adhering to the: (i) MVPA recommendation, (ii) sufficient muscle‐strengthening activity (≥2 days/week), (iii) sufficient balance training (≥2 days/week), and (iv) Finnish health‐enhancing PA recommendations (Finnish recommendations) were calculated. Associations with sociodemographic variables (eg, age, education level, self‐rated health) were assessed using multiple logistic regression analyses. Of 69,032 respondents, 92.6% (n=64,380, response rate =48.6%, 18‐98 years) reported on their physical activity levels. A total of 31.2% (95% CI: 30.8%‐31.6%) met the aerobic MVPA recommendation, 17.2% (95% CI: 16.9%‐17.6%) reported sufficient muscle‐strengthening activity, 6.7% (95% CI: 6.4%‐6.9%) reported sufficient balance training, and 10.8% (95% CI: 10.5%‐11.1%) met the Finnish recommendations. In the adjusted analysis, those with poorer self‐rated health, older age, lower education levels, and those classified overweight or obese were independently associated with lower odds of meeting the Finnish recommendations. The vast majority of Finnish adults do not meet the full PA recommendations. Public health action is needed to increase PA in Finland.