Association of Accelerometer-Measured Sedentary Accumulation Patterns With Incident Cardiovascular Disease, Cancer, and All-Cause Mortality.

Background Emerging evidence suggests accruing sedentary behavior (SB) in relatively more prolonged periods may convey additional cardiometabolic risks, but few studies have examined prospective outcomes. We examined the association of SB accumulation patterns with incident cardiovascular disease (CVD), cancer, and all-cause mortality (ACM). Methods and Results Data were from 7671 EPIC-Norfolk (European Prospective Investigation Into Cancer and Nutrition-Norfolk) cohort middle- to older-aged adults who wore accelerometers on the right hip for 4 to 7 days. Cox proportional hazards regression modeled associations between 2 measures of SB accumulation and incident CVD, cancer, and ACM. These were usual SB bout duration (the midpoint of each individual's SB accumulation curve, fitted using nonlinear regression) and alpha (hybrid measure of bout frequency and duration, with higher values indicating relatively shorter bouts and fewer long bouts). Models were adjusted for potential confounders, then further for 24-hour time-use compositions. During mean follow-up time of 6.4 years, 339 ACM, 1106 CVD, and 516 cancer events occurred. Elevated rates of incident cancer and ACM were seen with more prolonged SB accumulation (lower alpha, higher usual SB bout duration) but not CVD. For usual SB bout duration and alpha, respectively, the confounder-adjusted hazard ratios per SD of the exposure were 1.12 (95% CI, 1.02-1.23) and 0.88 (95% CI, 0.79-0.98) with incident cancer and 1.16 (95% CI, 1.07-1.26) and 0.80 (95% CI, 0.72-0.89) with ACM (all P<0.05). Further adjustment for 24-hour time use weakened associations with ACM for usual bout duration (hazard ratio, 1.06; 95% CI, 0.97-1.16; P=0.209) and partially for alpha (hazard ratio, 0.87; 95% CI, 0.77-0.99; P=0.029). Conclusions Accruing SB in longer bout durations was associated with higher rates of incident cancer and ACM but not with incident CVD, with some evidence of direct SB accumulation effects independent of 24-hour time use. Findings provide some support for considering SB accumulation as an adjunct target of messaging to "sit less and move more."

Dietary and Physical Activity Changes and Adherence to WCRF/AICR Cancer Prevention Recommendations following a Remotely Delivered Weight Loss Intervention for Female Breast Cancer Survivors: The Living Well after Breast Cancer Randomized Controlled Trial.

BACKGROUND: Diet, exercise, and weight management are key in improving outcomes for breast cancer survivors, with international recommendations for cancer survivors relating to these behaviors. However, few behavioral interventions have reported outcomes aligned specifically with these recommendations. OBJECTIVE: To evaluate a remotely delivered weight loss intervention vs usual care for female breast cancer survivors, on changes in multiple diet and physical activity behaviors. DESIGN: A randomized controlled trial with assessments at study baseline, 6-, 12-, and 18 months (ie, mid-intervention, post-intervention, and non-contact follow-up). PARTICIPANTS/SETTING: Participants were recruited between October 2012 and December 2014 through hospitals in Brisbane, Australia, and the state-based cancer registry. Eligible participants (women aged 18 to 75 years with body mass index 25 to 45 kg/m2 who were diagnosed with stage I through III breast cancer during previous 2 years) were randomly allocated to intervention (n = 79) or usual care (n = 80). INTERVENTION: Participants randomized to the intervention group received 22 counseling telephone calls targeting diet and physical activity aimed at achieving 5% to 10% weight loss, and optional text messages, over 12 months. Usual care participants received their standard medical care and brief feedback following each assessment, which was similar to that provided to intervention participants with the exception that usual care participants' results were not compared with national and study recommendations. MAIN OUTCOME MEASURES: Dietary intake (24-hour recalls), physical activity (hip-worn GT3X+ accelerometer [Actigraph]), sitting time (thigh-worn activPAL3 [PAL Technologies Limited), and adherence to World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) recommendations for cancer survivors (0 to 7 score) were measured at each assessment, with data collected between November 2012 and October 2016. STATISTICAL ANALYSES PERFORMED: Intervention effects were assessed by linear mixed models, accounting for repeated measures and baseline values. Significance was set at P < 0.05. RESULTS: At baseline, participants were aged 55 ± 9 years, with a body mass index of 31.4 ± 5.0 kg/m2, 10.7 ± 5.0 months postdiagnosis, and primarily non-minority. At baseline, only 8% (n = 12) of participants met ≥5 out of seven WCRF/AICR recommendations (WCRF/AICR adherence score = 3.8 ± 1.0). At 12 months, significant intervention effects were observed in walking/running (+21 minutes/week; 95% CI 4 to 38) and WCRF/AICR adherence scores (+0.3 points; 95% CI 0.0 to 0.6) only. At 18 months, significant intervention effects were observed for energy intake (-229 kcal/day energy; 95% CI -373 to -84), total fat (-10 g/day; 95% CI -18 to -2), and saturated fat (-5 g/day; 95% CI -9 to -1), and were sustained for WCRF/AICR adherence scores (+0.5 points; 95% CI 0.2 to 0.8). CONCLUSIONS: This remotely delivered weight loss intervention led to sustained improvements in WCRF/AICR adherence scores, and some improvements in diet and physical activity. These findings provide support for the health benefit of programs targeting lifestyle behaviors in line with cancer survivor recommendations, and the potential for dissemination of such programs for women following treatment for early-stage breast cancer.

Effect of a Remotely Delivered Weight Loss Intervention in Early-Stage Breast Cancer: Randomized Controlled Trial.

Limited evidence exists on the effects of weight loss on chronic disease risk and patient-reported outcomes in breast cancer survivors. Breast cancer survivors (stage I-III; body mass index 25-45 kg/m2) were randomized to a 12-month, remotely delivered (22 telephone calls, mailed material, optional text messages) weight loss (diet and physical activity) intervention (n = 79) or usual care (n = 80). Weight loss (primary outcome), body composition, metabolic syndrome risk score and components, quality of life, fatigue, musculoskeletal pain, menopausal symptoms, fear of recurrence, and body image were assessed at baseline, 6 months, 12 months (primary endpoint), and 18 months. Participants were 55 ± 9 years and 10.7 ± 5.0 months post-diagnosis; retention was 81.8% (12 months) and 80.5% (18 months). At 12-months, intervention participants had significantly greater improvements in weight (-4.5% [95%CI: -6.5, -2.5]; p < 0.001), fat mass (-3.3 kg [-4.8, -1.9]; p < 0.001), metabolic syndrome risk score (-0.19 [-0.32, -0.05]; p = 0.006), waist circumference (-3.2 cm [-5.5, -0.9]; p = 0.007), fasting plasma glucose (-0.23 mmol/L [-0.44, -0.02]; p = 0.032), physical quality of life (2.7 [0.7, 4.6]; p = 0.007; Cohen's effect size (d) = 0.40), musculoskeletal pain (-0.5 [-0.8, -0.2]; p = 0.003; d = 0.49), and body image (-0.2 [-0.4, -0.0]; p = 0.030; d = 0.31) than usual care. At 18 months, effects on weight, adiposity, and metabolic syndrome risk scores were sustained; however, significant reductions in lean mass were observed (-1.1 kg [-1.7, -0.4]; p < 0.001). This intervention led to sustained improvements in adiposity and metabolic syndrome risk.

Sedentary time in people with obstructive airway diseases.

Sedentary time (ST) and light-intensity physical activity (LIPA) are movement behaviours associated with important health outcomes, but are not widely explored in respiratory diseases. We aimed to describe their volume and/or accumulation patterns in moderate-severe COPD, bronchiectasis and severe asthma using the accurate postural-based accelerometer activPAL, contrasting these values with a non-respiratory population. We also sought to test the cross-sectional associations of these behaviours with disease characteristics by diagnostic group, and as a combined label-free disease group. RESULTS: Adults with COPD (n = 64), bronchiectasis (n = 61), severe asthma (n = 27), and controls (n = 61) underwent cross-sectional measurements of volume and/or accumulation patterns of ST and LIPA. The prevalence and characteristics, and associations with exercise capacity, health-status, airflow-limitation, dyspnoea, systemic inflammation and exacerbations were analysed. ST volumes in COPD were higher than that of bronchiectasis and severe asthma. Values in bronchiectasis and severe asthma were similar to each other and controls (≈8.9 h/day). Their accumulation patterns were also significantly better than in COPD, but similar if not worse compared to controls. LIPA volumes in bronchiectasis and severe asthma were also higher than those of COPD (p < 0.05) and controls. In bronchiectasis and COPD, lower levels/better patterns of ST accumulation, as well as higher LIPA volume were associated with better clinical characteristics. These associations may be mediated by airflow limitation. CONCLUSIONS: The discordance between engagement in ST volume versus ST patterns highlights the importance of accounting for both these different yet complementary metrics. ST and LIPA are low-intensity activities associated with important clinical characteristics in people with chronic respiratory diseases. TRIAL REGISTRATION: Not applicable.

Translating research into practice: outcomes from the Healthy Living after Cancer partnership project.

BACKGROUND: Healthy Living after Cancer (HLaC) was a national dissemination and implementation study of an evidence-based lifestyle intervention for cancer survivors. The program was imbedded into existing telephone cancer information and support services delivered by Australian state-based Cancer Councils (CC). We report here the reach, effectiveness, adoption, implementation, and maintenance of the program. METHODS: In this phase IV study (single-group, pre-post design) participants - survivors of any type of cancer, following treatment with curative intent - received up to 12 nurse/allied health professional-led telephone health coaching calls over 6 months. Intervention delivery was grounded in motivational interviewing, with emphasis on evidence-based behaviour change strategies. Using the RE-AIM evaluation framework, primary outcomes were reach, indicators of program adoption, implementation, costs and maintenance. Secondary (effectiveness) outcomes were participant-reported anthropometric, behavioural and psychosocial variables including: weight; physical activity; dietary intake; quality-of-life; treatment side-effects; distress; and fear of cancer recurrence and participant satisfaction. Changes were evaluated using linear mixed models, including terms for timepoint (0/6 months), strata (Cancer Council), and timepoint x strata. RESULTS: Four of 5 CCs approached participated in the study. In total, 1183 cancer survivors were referred (mostly via calls to the Cancer Council telephone information service). Of these, 90.4% were eligible and 88.7% (n = 791) of those eligible consented to participate. Retention rate was 63.4%. Participants were mostly female (88%), aged 57 years and were overweight (BMI = 28.8 ± 6.5 kg/m2). Improvements in all participant-reported outcomes (standardised effect sizes of 0.1 to 0.6) were observed (p < 0.001). The program delivery costs were on average AU$427 (US$296) per referred cancer survivor. CONCLUSIONS: This telephone-delivered lifestyle intervention, which was feasibly implemented by Cancer Councils, led to meaningful and statistically significant improvements in cancer survivors' health and quality-of-life at a relatively low cost. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ANZCTR) - ACTRN12615000882527 (registered on 24/08/2015).

What strategies do desk-based workers choose to reduce sitting time and how well do they work? Findings from a cluster randomised controlled trial.

BACKGROUND: Large amounts of sitting at work have been identified as an emerging occupational health risk, and findings from intervention trials have been reported. However, few such reports have examined participant-selected strategies and their relationships with behaviour change. METHODS: The Stand Up Victoria cluster-randomised controlled trial was a workplace-delivered intervention comprising organisational, environmental and individual level behaviour change strategies aimed at reducing sitting time in desk-based workers. Sit-stand workstations were provided, and participants (n = 134; intervention group only) were guided by health coaches to identify strategies for the 'Stand Up', 'Sit Less', and 'Move More' intervention targets, including how long they would stand using the workstation. Three-month workplace sitting and activity changes (activPAL3-assessed total sitting, prolonged sitting (i.e., sitting ≥30 min continuously) and purposeful walking) were evaluated in relation to the number (regression analysis) and types of strategies (decision-tree analysis). RESULTS: Over 80 different strategies were nominated by participants. Each additional strategy nominated for the 'Stand Up' intervention target (i.e. number of strategies) was associated with a reduction in prolonged sitting of 27.6 min/8-h workday (95% CI: -53.1, - 2.1, p = 0.034). Types of strategies were categorised into 13 distinct categories. Strategies that were task-based and phone-based were common across all three targets. The decision tree models did not select any specific strategy category as predicting changes in prolonged sitting ('Stand Up'), however four strategy categories were identified as important for total sitting time ('Sit Less') and three strategy categories for purposeful walking ('Moving More'). The uppermost nodes (foremost predictors) were nominating > 3 h/day of workstation standing (reducing total workplace sitting) and choosing a 'Move More' task-based strategy (purposeful walking). CONCLUSIONS: Workers chose a wide range of strategies, with both strategy choice and strategy quantity appearing relevant to behavioural improvement. Findings support a tailored and pragmatic approach to encourage a change in sitting and activity in the workplace. Evaluating participant-selected strategies in the context of a successful intervention serves to highlight options that may prove feasible and effective in other desk-based workplace environments. TRIAL REGISTRATION: This trial was prospectively registered with the Australian New Zealand Clinical Trials register ( ACTRN12611000742976 ) on 15 July 2011.

Correlates of physical activity and sedentary time in young adults: the Western Australian Pregnancy Cohort (Raine) Study.

BACKGROUND: The socioecological model proposes a wide array of factors that influence behaviours. There is a need to understand salient correlates of these activity behaviours in a specific population. However, few studies identified socio-demographic, behavioural, physical, and psychological correlates of objectively-assessed physical activity and sedentary time in young adults. METHODS: This was a cross-sectional analysis of participants in the Raine Study (a pregnancy cohort started in 1989). Australian young adults (mean 22.1 years ± SD 0.6) wore Actigraph GT3X+ accelerometers on the hip 24 h/day for seven days to assess moderate-to-vigorous physical activity (MVPA) and sedentary time (n = 256 women, n = 219 men). Potential correlates were assessed via clinical assessment and questionnaire and included socio-demographic variables (ethnicity, relationship status, work/study status, education, mothers education), health behaviours (food intake, alcohol consumption, smoking status, sleep quality), and physical and psychological health aspects (anthropometrics, diagnosed disorders, mental health, cognitive performance). Backwards elimination (p < 0.2 for retention) with mixed model regressions were used and the gender-stratified analyses were adjusted for demographic variables, waking wear time and number of valid days. RESULTS: Increased time spent in MVPA was associated with: being single (IRR 1.44 vs in a relationship living together, 95%CI: 1.17, 1.77, p = .001) in women; and better sleep quality in men (lower scores better IRR 0.97, 95%CI: 0.93, 1.00). Less time spent sedentary was associated with: lower mother's education (- 32.1 min/day, 95%CI -52.9, 11.3, p = 0.002 for having mother with no university degree vs at least a baccalaureate degree) and smoking (- 44.3 min/day, 95%CI: - 72.8, - 15.9, p = .0002) for women; lower education status (- 32.1 min/day, 95%CI: -59.5, - 4.8, p = 0.021 for having no university degree vs at least a baccalaureate degree) and lower depression scores in men (- 2.0, 95%CI: - 3.5, - 0.4, p = 0.014); more alcoholic drinks per week for women (- 1.9 min/day, 95%CI: -3.1, - 0.6, p = 0.003) and men (- 1.0, 95%CI: -1.8, - 0.3, p = 0.007). CONCLUSIONS: Less desirable correlates were associated with positive levels of activity in young Australian adult women and men. Interventions to increase MVPA and decrease sedentary activity in young adults need to specifically consider the life stage of young adults.

Relative validity of a brief Fat and Fibre Behaviour Questionnaire in a population of overweight and obese breast cancer survivors: A note of caution.

AIM: Dietary intake assessment is often difficult in research contexts because of time and resource constraints and participant burden. Valid, reliable and brief assessments of dietary behaviour are needed. Additionally, examination of instrument performance in a variety of populations is needed. This study assessed relative validity and responsiveness to change of the Fat and Fibre Behaviour Questionnaire (FFBQ) in a population of breast cancer survivors compared with dietary intake measured by 24-hour recalls. METHODS: Data were collected at baseline and six months after baseline of a six-month, randomised controlled trial that evaluated a telephone-based behavioural weight loss intervention (n = 45) compared to usual care (n = 45) among overweight and obese breast cancer survivors. The FFBQ's total index, fat index and fibre index were assessed for relative validity against two 24-hour recalls (Pearson's correlations). Responsiveness to change was assessed as intervention group change divided by standard deviation of usual care group change. RESULTS: Pearson's correlations of the fat index with fat intake measures ranged from -0.09 to -0.30 (P < 0.05) at baseline and from -0.19 to -0.28 (P < 0.05) for dietary change. Correlations of the fibre index with unadjusted and energy-adjusted fibre intake measures (0.25-0.32, P < 0.05) were significant at baseline only. Both the FFBQ and 24-hour recall were responsive to fat-related dietary changes and not responsive to fibre-related changes. CONCLUSIONS: The FFBQ showed small to medium relative validity against 24-hour dietary recall for assessing fat and fibre dietary behaviours and changes in dietary fat, and was responsive to fat-related dietary changes in this population.

Physical Activity and Sedentary Behavior in Breast and Colon Cancer Survivors Relative to Adults Without Cancer.

OBJECTIVE: To assess differences in accelerometer-assessed moderate- to vigorous-intensity physical activity (MVPA), light-intensity physical activity, and sedentary time between cancer survivors and adults without cancer. PATIENTS AND METHODS: Accelerometer data collected from 241 breast cancer survivors (ACCEL-Breast study, 2013) and 171 colon cancer survivors (ACCEL-Colon study, 2012-2013) were pooled with data collected from adults without cancer (Australian Diabetes, Obesity and Lifestyle accelerometer substudy, 2011-2012). Linear regression was used to estimate differences in physical activity and sedentary behavior levels between cancer survivors and adults without cancer, adjusted for potential confounding factors. RESULTS: The mean MVPA was significantly higher among breast cancer survivors than among females who had not had cancer (29 vs 22 min/d; P<.001). Colon cancer survivors had significantly lower levels of light activity than did adults without cancer (311 vs 338 min/d; P<.001), more sedentary time (532 vs 507 min/d; P=.003), and more prolonged sedentary time (210 vs 184 min/d; P=.002). CONCLUSION: Contrary to findings from previous research (based on self-reported physical activity), cancer survivors engaged in more (breast) or equivalent (colon) MVPA compared with adults without cancer. Differences between colon cancer survivors and adults without cancer for light activity and sedentary behavior highlight the importance of considering the full activity spectrum in the context of cancer control.

Living well after breast cancer randomized controlled trial protocol: evaluating a telephone-delivered weight loss intervention versus usual care in women following treatment for breast cancer.

BACKGROUND: Obesity, physical inactivity and poor diet quality have been associated with increased risk of breast cancer-specific and all-cause mortality as well as treatment-related side-effects in breast cancer survivors. Weight loss intervention trials in breast cancer survivors have shown that weight loss is safe and achievable; however, few studies have examined the benefits of such interventions on a broad range of outcomes and few have examined factors important to translation (e.g. feasible delivery method for scaling up, assessment of sustained changes, cost-effectiveness). The Living Well after Breast Cancer randomized controlled trial aims to evaluate a 12-month telephone-delivered weight loss intervention (versus usual care) on weight change and a range of secondary outcomes including cost-effectiveness. METHODS/DESIGN: Women (18-75 years; body mass index 25-45 kg/m2) diagnosed with stage I-III breast cancer in the previous 2 years are recruited from public and private hospitals and through the state-based cancer registry (target n = 156). Following baseline assessment, participants are randomized 1:1 to either a 12-month telephone-delivered weight loss intervention (targeting diet and physical activity) or usual care. Data are collected at baseline, 6-months (mid-intervention), 12-months (end-of-intervention) and 18-months (maintenance). The primary outcome is change in weight at 12-months. Secondary outcomes are changes in body composition, bone mineral density, cardio-metabolic and cancer-related biomarkers, metabolic health and chronic disease risk, physical function, patient-reported outcomes (quality of life, fatigue, menopausal symptoms, body image, fear of cancer recurrence) and behaviors (dietary intake, physical activity, sitting time). Data collected at 18-months will be used to assess whether outcomes achieved at end-of-intervention are sustained six months after intervention completion. Cost-effectiveness will be assessed, as will mediators and moderators of intervention effects. DISCUSSION: This trial will provide evidence needed to inform the wide-scale provision of weight loss, physical activity and dietary interventions as part of routine survivorship care for breast cancer survivors. TRIAL REGISTRATION: Australian and New Zealand Clinical Trial Registry (ANZCTR) - ACTRN12612000997853 (Registered 18 September 2012).

Associations of sedentary time and patterns of sedentary time accumulation with health-related quality of life in colorectal cancer survivors.

Sedentary behavior (sitting/lying at low energy expenditure while awake) is emerging as an important risk factor that may compromise the health-related quality of life (HRQoL) of colorectal cancer (CRC) survivors. We examined associations of sedentary time with HRQoL in CRC survivors, 2-10 years post-diagnosis. In a cross-sectional study, stage I-III CRC survivors (n = 145) diagnosed (2002-2010) at Maastricht University Medical Center+, the Netherlands, wore the thigh-mounted MOX activity monitor 24 h/day for seven consecutive days. HRQoL outcomes were assessed by validated questionnaires (EORTC QLQ-C30, WHODAS II, Checklist Individual Strength, and Hospital Anxiety and Depression Scale). Confounder-adjusted linear regression models were used to estimate associations with HRQoL outcomes of MOX-derived total and prolonged sedentary time (in prolonged sedentary bouts ≥ 30 min), and usual sedentary bout duration, corrected for waking wear time. On average, participants spent 10.2 h/day sedentary (SD, 1.6), and 4.5 h/day in prolonged sedentary time (2.3). Mean usual sedentary bout duration was 27.3 min (SD, 16.8). Greater total and prolonged sedentary time, and longer usual sedentary bout duration were associated with significantly (P < 0.05) lower physical functioning, and higher disability and fatigue scores. Greater prolonged sedentary time and longer usual sedentary bout duration also showed significant associations with lower global quality of life and role functioning. Associations with distress and social functioning were non-significant. Sedentary time was cross-sectionally associated with poorer HRQoL outcomes in CRC survivors. Prospective studies are needed to investigate whether sedentary time reduction is a potential target for lifestyle interventions aiming to improve the HRQoL of CRC survivors.

Objectively measured patterns of sedentary time and physical activity in young adults of the Raine study cohort.

BACKGROUND: To provide a detailed description of young adults' sedentary time and physical activity. METHODS: 384 young women and 389 young men aged 22.1 ± 0.6 years, all participants in the 22 year old follow-up of the Raine Study pregnancy cohort, wore Actigraph GT3X+ monitors on the hip for 24 h/day over a one-week period for at least one 'valid' day (≥10 h of waking wear time). Each minute epoch was classified as sedentary, light, moderate or vigorous intensity using 100 count and Freedson cut-points. Mixed models assessed hourly and daily variation; t-tests assessed gender differences. RESULTS: The average (mean ± SD) waking wear time was 15.0 ± 1.6 h/day, of which 61.4 ± 10.1% was spent sedentary, 34.6 ± 9.1% in light-, 3.7 ± 5.3% in moderate- and, 0.3 ± 0.6% in vigorous-intensity activity. Average time spent in moderate to vigorous activity (MVPA) was 36.2 ± 27.5 min/day. Relative to men, women had higher sedentary time, but also higher vigorous activity time. The 'usual' bout duration of sedentary time was 11.8 ± 4.5 min in women and 11.7 ± 5.2 min in men. By contrast, other activities were accumulated in shorter bout durations. There was large variation by hour of the day and by day of the week in both sedentary time and MVPA. Evenings and Sundays through Wednesdays tended to be particularly sedentary and/or inactive. CONCLUSION: For these young adults, much of the waking day was spent sedentary and many participants were physically inactive (low levels of MVPA). We provide novel evidence on the time for which activities were performed and on the time periods when young adults were more sedentary and/or less active. With high sedentary time and low MVPA, young adults may be at risk for the life-course sequelae of these behaviours.

Associations of Low- and High-Intensity Light Activity with Cardiometabolic Biomarkers.

PURPOSE: Light-intensity physical activity (LIPA) accounts for much of adults' waking hours (≈40%) and substantially contributes to overall daily energy expenditure. Encompassing activity behaviors of low intensity (standing with little movement) to those of higher intensity (slow walking), LIPA is ubiquitous, yet little is known about how associations with health may vary depending on its intensity. We examined the associations of objectively assessed LIPA (categorized as either low LIPA [LLPA] or high LIPA [HLPA]) and moderate- to vigorous-intensity activity with cardiometabolic risk biomarkers. METHODS: Cardiometabolic biomarkers were measured in 4614 US adults (47 ± 17 yr) who participated in the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cycles. Multiple linear regression analyses examined the associations of three accelerometer-derived physical activity (SD increment per day) intensity categories (LLPA, 100-761 counts per minute; HLPA, 762-1951 counts per minute; moderate-intensity physical activity [MPA], 1952-5724 counts per minute; vigorous-intensity physical activity [VPA], ≥5725 counts per minute) with cardiometabolic biomarkers, adjusting for potential sociodemographic, behavioral, and medical confounders. RESULTS: All intensities of physical activity were beneficially associated with waist circumference, C-reactive protein, triglycerides, fasting insulin, ß-cell function, and insulin sensitivity (P < 0.05); only some activity intensities showed significant associations with systolic blood pressure (LLPA), body mass index, HDL cholesterol, fasting glucose, and 2-h plasma glucose (HLPA, MPA, and VPA). Generally, effect size increased with intensity of physical activity. Overall, further adjustment for waist circumference attenuated associations with MPA and VPA to a greater extent than associations with LLPA and HLPA. CONCLUSIONS: The cross-sectional findings provide novel evidence for the potential benefits of increasing both LLPA and HLPA. They further reinforce the established importance of moderate- to vigorous-intensity activity, the mainstay of public health recommendations.

Moderators of health behavior initiation and maintenance in a randomized telephone counseling trial.

OBJECTIVE: This study compares moderators of initiation and maintenance of health behavior changes. METHODS: Data come from a cluster-randomized, 12-month telephone counseling intervention for physical activity and diet, targeting type 2 diabetes or hypertension patients (n=434, Australia,2005-2007). Demographic and health-related characteristics, theoretical constructs, and baseline behavioral outcomes were considered as moderators. Mixed models, adjusting for baseline values, assessed moderation of intervention effects for trial outcomes (physical activity, intakes of fat, saturated fat, fiber, fruit, vegetables) at end-of-intervention (12 months/initiation) and maintenance follow-up (18 months), and compared moderation between these periods. RESULTS: Social support for physical activity and baseline physical activity were significant (p<0.05) moderators of physical activity at 12 months. Gender, marital status, social support for healthy eating, BMI, and number of chronic conditions were significant moderators of dietary changes at 12- and/or 18 months. Instances of moderation differing significantly between 12- and 18 months were: baseline physical activity for physical activity (initiation) and marital status for fat intake (maintenance). CONCLUSIONS: This exploratory study showed that moderation of physical activity and diet effects sometimes differed between initiation and maintenance. To identify unique moderators for initiation and/or maintenance of behavior changes, future studies need to report on and statistically test for such differences.

Reallocating time to sleep, sedentary behaviors, or active behaviors: associations with cardiovascular disease risk biomarkers, NHANES 2005-2006.

Sleep and sedentary and active behaviors are linked to cardiovascular disease risk biomarkers, and across a 24-hour day, increasing time in 1 behavior requires decreasing time in another. We explored associations of reallocating time to sleep, sedentary behavior, or active behaviors with biomarkers. Data (n = 2,185 full sample; n = 923 fasting subanalyses) from the cross-sectional 2005-2006 US National Health and Nutrition Examination Survey were analyzed. The amounts of time spent in sedentary behavior, light-intensity activity, and moderate-to-vigorous physical activity (MVPA) were derived from ActiGraph accelerometry (ActiGraph LLC, Pensacola, Florida), and respondents reported their sleep duration. Isotemporal substitution modeling indicated that, independent of potential confounders and time spent in other activities, beneficial associations (P < 0.05) with cardiovascular disease risk biomarkers were associated with the reallocation of 30 minutes/day of sedentary time with equal time of either sleep (2.2% lower insulin and 2.0% lower homeostasis model assessment of ß-cell function), light-intensity activity (1.9% lower triglycerides, 2.4% lower insulin, and 2.2% lower homeostasis model assessment of ß-cell function), or MVPA (2.4% smaller waist circumference, 4.4% higher high-density lipoprotein cholesterol, 8.5% lower triglycerides, 1.7% lower glucose, 10.7% lower insulin, and 9.7% higher homeostasis model assessment of insulin sensitivity. These findings provide evidence that MVPA may be the most potent health-enhancing, time-dependent behavior, with additional benefit conferred from light-intensity activities and sleep duration when reallocated from sedentary time.

Reducing office workers' sitting time: rationale and study design for the Stand Up Victoria cluster randomized trial.

BACKGROUND: Excessive time spent in sedentary behaviours (sitting or lying with low energy expenditure) is associated with an increased risk for type 2 diabetes, cardiovascular disease and some cancers. Desk-based office workers typically accumulate high amounts of daily sitting time, often in prolonged unbroken bouts. The Stand Up Victoria study aims to determine whether a 3-month multi-component intervention in the office setting reduces workplace sitting, particularly prolonged, unbroken sitting time, and results in improvements in cardio-metabolic biomarkers and work-related outcomes, compared to usual practice. METHODS/DESIGN: A two-arm cluster-randomized controlled trial (RCT), with worksites as the unit of randomization, will be conducted in 16 worksites located in Victoria, Australia. Work units from one organisation (Department of Human Services, Australian Government) will be allocated to either the multi-component intervention (organisational, environmental [height-adjustable workstations], and individual behavioural strategies) or to a usual practice control group. The recruitment target is 160 participants (office-based workers aged 18-65 years and working at least 0.6 full time equivalent) per arm. At each assessment (0- [baseline], 3- [post intervention], and 12-months [follow-up]), objective measurement via the activPAL3 activity monitor will be used to assess workplace: sitting time (primary outcome); prolonged sitting time (sitting time accrued in bouts of ≥30 minutes); standing time; sit-to-stand transitions; and, moving time. Additional outcomes assessed will include: non-workplace activity; cardio-metabolic biomarkers and health indicators (including fasting glucose, lipids and insulin; anthropometric measures; blood pressure; and, musculoskeletal symptoms); and, work-related outcomes (presenteeism, absenteeism, productivity, work performance). Incremental cost-effectiveness and identification of both workplace and individual-level mediators and moderators of change will also be evaluated. DISCUSSION: Stand Up Victoria will be the first cluster-RCT to evaluate the effectiveness of a multi-component intervention aimed at reducing prolonged workplace sitting in office workers. Strengths include the objective measurement of activity and assessment of the intervention on markers of cardio-metabolic health. Health- and work-related benefits, as well as the cost-effectiveness of the intervention, will help to inform future occupational practice. TRIAL REGISTRATION: ACTRN1211000742976.

Light-intensity physical activity and cardiometabolic biomarkers in US adolescents.

BACKGROUND: The minimal physical activity intensity that would confer health benefits among adolescents is unknown. The purpose of this study was to examine the associations of accelerometer-derived light-intensity (split into low and high) physical activity, and moderate- to vigorous-intensity physical activity with cardiometabolic biomarkers in a large population-based sample. METHODS: The study is based on 1,731 adolescents, aged 12-19 years from the 2003/04 and 2005/06 National Health and Nutrition Examination Survey. Low light-intensity activity (100-799 counts/min), high light-intensity activity (800 counts/min to <4 METs) and moderate- to vigorous-intensity activity (≥ 4 METs, Freedson age-specific equation) were accelerometer-derived. Cardiometabolic biomarkers, including waist circumference, systolic blood pressure, diastolic blood pressure, HDL-cholesterol, and C-reactive protein were measured. Triglycerides, LDL- cholesterol, insulin, glucose, and homeostatic model assessments of ß-cell function (HOMA-%B) and insulin sensitivity (HOMA-%S) were also measured in a fasting sub-sample (n=807). RESULTS: Adjusted for confounders, each additional hour/day of low light-intensity activity was associated with 0.59 (95% CI: 1.18-0.01) mmHG lower diastolic blood pressure. Each additional hour/day of high light-intensity activity was associated with 1.67 (2.94-0.39) mmHG lower diastolic blood pressure and 0.04 (0.001-0.07) mmol/L higher HDL-cholesterol. Each additional hour/day of moderate- to vigorous-intensity activity was associated with 3.54 (5.73-1.35) mmHG lower systolic blood pressure, 5.49 (1.11-9.77)% lower waist circumference, 25.87 (6.08-49.34)% lower insulin, and 16.18 (4.92-28.53)% higher HOMA-%S. CONCLUSIONS: Time spent in low light-intensity physical activity and high light-intensity physical activity had some favorable associations with biomarkers. Consistent with current physical activity recommendations for adolescents, moderate- to vigorous-intensity activity had favorable associations with many cardiometabolic biomarkers. While increasing MVPA should still be a public health priority, further studies are needed to identify dose-response relationships for light-intensity activity thresholds to inform future recommendations and interventions for adolescents.

Correlates of Omani adults' physical inactivity and sitting time.

OBJECTIVE: To inform public health approaches for chronic disease prevention, the present study identified sociodemographic, anthropometric and behavioural correlates of work, transport and leisure physical inactivity and sitting time among adults in Oman. DESIGN: Cross-sectional study using the WHO STEPwise study methodology. SETTING: Sur City, Oman. SUBJECTS: Men and women aged 20 years and older (n = 1335) in the Sur City Healthy Lifestyle Study who had complete data for demographic variables (gender, age, education, work status and marital status), BMI and behavioural risk factors ­ smoking and dietary habits plus physical inactivity and sitting time (the outcome variables). RESULTS: The highest level of physical inactivity was in the leisure domain (55.4 %); median sitting time was about 2 h/d. Gender-stratified logistic regression models found that the statistically significant (P < 0.05) correlates of inactivity (in one or more domains) were age, work status and fruit and vegetable intake in women, and age, education, work status, marital status and BMI in men. Gender-stratified linear regression models found that the statistically significant correlates of sitting time were age, work status and BMI in women and education in men. CONCLUSIONS: Findings suggest that public health interventions need to be gender responsive and focus on domain-specific physical inactivity. In the Omani context, this might include gender-segregated exercise facilities to promote leisure physical activity among women and walking-friendly environmental initiatives to promote transport physical activity among men. Further evidence on barriers to physical activity and factors that influence prolonged sitting is required to develop relevant public health interventions.

A randomized trial of a telephone-delivered exercise intervention for non-urban dwelling women newly diagnosed with breast cancer: exercise for health.

BACKGROUND: Physical activity is important following breast cancer. Trials of non-face-to-face interventions are needed to assist in reaching women living outside major metropolitan areas. PURPOSE: This study seeks to evaluate the feasibility and effectiveness of a telephone-delivered, mixed aerobic and resistance exercise intervention for non-urban Australian women with breast cancer. METHODS: A randomized controlled trial comparing an 8-month intervention delivered by exercise physiologists (n = 73) to usual care (n = 70). RESULTS: Sixty-one percent recruitment rate and 96% retention at 12 months; 79% of women in the intervention group received at least 75% of calls; odds (OR, 95% CI) of meeting intervention targets favored the intervention group for resistance training (OR 3.2; 1.2, 8.9) and aerobic (OR 2.1; 0.8, 5.5) activity. CONCLUSIONS: Given the limited availability of physical activity programs for non-urban women with breast cancer, results provide strong support for feasibility and modest support for the efficacy of telephone-delivered interventions.

Associations of objectively-assessed physical activity and sedentary time with depression: NHANES (2005-2006).

BACKGROUND: Studies provide conflicting evidence for the protective effects of moderate-to-vigorous-intensity physical activity on depression. Recent evidence suggests that sedentary behaviors may also be associated with depression. PURPOSE: To examine the associations of accelerometer-derived moderate-to-vigorous-intensity physical activity and sedentary time with depression among a population-based sample. METHODS: Cross-sectional study using 2,862 adults from the 2005-2006 US National Health and Nutrition Examination Survey. ActiGraph accelerometers were used to derive both moderate-to-vigorous-intensity physical activity and sedentary time. RESULTS: Depression occurred in 6.8% of the sample. For moderate-to-vigorous-intensity physical activity, compared with those in quartile 1 (least active), significantly lower odds of depression were observed for those participants in quartiles 2 (OR=0.55, 95% CI, 0.34 to 0.89), 3 (OR=0.49, 95% CI, 0.26 to 0.93), and 4 (most active) (OR=0.37, 95% CI, 0.20 to 0.70) (p for trend p<0.01). In overweight/obese participants only, those in quartile 4 (most sedentary) had significantly higher odds for depression than those in quartile 1 (least sedentary) [quartile 3 vs 1 (OR=1.94, 95% CI, 1.01 to 3.68) and 4 vs 1 (OR=3.09, 95% CI, 1.25 to 7.68)]. CONCLUSION: The current study identified lower odds of depression were associated with increasing moderate-to-vigorous-intensity physical activity and decreasing sedentary time, at least within overweight/obese adults.