Number Of Sedentary Bouts Research Articles

Sedentary Behavior and Incident Dementia Among Older Adults.

Sedentary behavior is associated with cardiometabolic disease and mortality, but its association with dementia is unclear. To investigate whether accelerometer-assessed sedentary behavior is associated with incident dementia. A retrospective study of prospectively collected data from the UK Biobank including 49 841 adults aged 60 years or older without a diagnosis of dementia at the time of wearing the wrist accelerometer and living in England, Scotland, or Wales. Follow-up began at the time of wearing the accelerometer (February 2013 to December 2015) and continued until September 2021 in England, July 2021 in Scotland, and February 2018 in Wales. Mean daily sedentary behavior time (included in the primary analysis) and mean daily sedentary bout length, maximum daily sedentary bout length, and mean number of daily sedentary bouts (included in the secondary analyses) were derived from a machine learning-based analysis of 1 week of wrist-worn accelerometer data. Incident all-cause dementia diagnosis from inpatient hospital records and death registry data. Cox proportional hazard models with linear and cubic spline terms were used to assess associations. A total of 49 841 older adults (mean age, 67.19 [SD, 4.29] years; 54.7% were female) were followed up for a mean of 6.72 years (SD, 0.95 years). During this time, 414 individuals were diagnosed with incident all-cause dementia. In the fully adjusted models, there was a significant nonlinear association between time spent in sedentary behavior and incident dementia. Relative to a median of 9.27 hours/d for sedentary behavior, the hazard ratios (HRs) for dementia were 1.08 (95% CI, 1.04-1.12, P < .001) for 10 hours/d, 1.63 (95% CI, 1.35-1.97, P < .001) for 12 hours/d, and 3.21 (95% CI, 2.05-5.04, P < .001) for 15 hours/d. The adjusted incidence rate of dementia per 1000 person-years was 7.49 (95% CI, 7.48-7.49) for 9.27 hours/d of sedentary behavior, 8.06 (95% CI, 7.76-8.36) for 10 hours/d, 12.00 (95% CI, 10.00-14.36) for 12 hours/d, and 22.74 (95% CI, 14.92-34.11) for 15 hours/d. Mean daily sedentary bout length (HR, 1.53 [95% CI, 1.03-2.27], P = .04 and 0.65 [95% CI, 0.04-1.57] more dementia cases per 1000 person-years for a 1-hour increase from the mean of 0.48 hours) and maximum daily sedentary bout length (HR, 1.15 [95% CI, 1.02-1.31], P = .02 and 0.19 [95% CI, 0.02-0.38] more dementia cases per 1000 person-years for a 1-hour increase from the mean of 1.95 hours) were significantly associated with higher risk of incident dementia. The number of sedentary bouts per day was not associated with higher risk of incident dementia (HR, 1.00 [95% CI, 0.99-1.01], P = .89). In the sensitivity analyses, after adjustment for time spent in sedentary behavior, the mean daily sedentary bout length and the maximum daily sedentary bout length were no longer significantly associated with incident dementia. Among older adults, more time spent in sedentary behaviors was significantly associated with higher incidence of all-cause dementia. Future research is needed to determine whether the association between sedentary behavior and risk of dementia is causal.

Objective assessment of the association between frailty and sedentary behavior in older adults: a cross-sectional study

BackgroundGiven the inconsistent findings of the association between frailty and sedentary behavior in older adults, this cross-sectional study investigated the aforementioned association using four different frailty criteria and two sedentary behavior indices in older adults.MethodsData from older adults (age ≥ 65 y) who participated in health examinations or attended outpatient integrated clinics at a medical center in Taipei, Taiwan, were collected. Frailty was measured using the modified Fried Frailty Phenotype (mFFP), Clinical Frailty Scale in Chinese Translation (CFS-C), Study of Osteoporotic Fractures (SOF) index, and Clinical Frailty-Deficit Count (CF-DC) index; sedentary behavior was assessed with a waist-worn accelerometer. Adjusted linear regression ascertained the association between frailty and both sedentary behavior outcomes.ResultsAmong the 214 participants (mean age 80.82 ± 7.14 y), 116 were women. The average total sedentary time and number of sedentary bouts were 609.74 ± 79.29 min and 5.51 ± 2.09 times per day, respectively. Frail participants had a longer total sedentary time (odds ratio [OR]: 30.13, P = .01 and 39.43, P < .001) and more sedentary bouts (OR: 3.50 and 5.86, both P < .001) on mFFP and CFS-C assessments, respectively. The SOF index revealed more sedentary bouts among frail than in robust participants (OR: 2.06, P = .009), without a significant difference in the total sedentary time. Frail participants defined by the CF-DC index were more likely to have frequent sedentary bouts (OR: 2.03, P = .016), but did not have a longer total sedentary time.ConclusionsRegardless of the frailty criteria adopted, frailty was positively associated with the number of sedentary bouts per day in older adults. A significant correlation between frailty and total sedentary time was detected only with mFFP and CFS-C indices. Further research may target decreasing the sedentary bouts in older adults as a strategy to improve frailty.

The association between daily sedentary and active bout frequency with mortality risk in older men using accelerometry.

Time awake with advancing age is increasingly spent sedentary and has several negative health consequences. We examined associations between the frequency of daily sedentary and active bouts with all-cause mortality. Data are from 2816 men in the Osteoporotic Fractures in Men (MrOS) Study (mean age ± SD: 79.1 ± 5.2 years) with free-living activity monitor (SenseWear® Pro3 Armband) data (5.1 ± 0.3 days worn >90%) at the Year 7 visit (2007-2009). Sedentary bout frequency was defined as the number of sedentary bouts per day lasting 5+ min to activity of any intensity. Active bout frequency was defined as the number of active bouts per day lasting 5+ min to sedentary behavior. Sleep time was excluded from the analysis. Deaths were centrally adjudicated using death certificates. Cox proportional hazard models were used to separately examine associations between quartiles of sedentary (Q1 referent, <13.6 bouts/day) or active (Q1 referent, <5 bouts/day) bout frequency with mortality. After 9.3 ± 3.8 years of follow-up, 1487 (52.8%) men died. Men averaged 16.8 ± 5.1 and 8.2 ± 4.2 sedentary and active bouts/day, respectively. After full covariate adjustment, each quartile reflecting more frequent sedentary bouts (Q4 vs. Q1 HR: 0.69, 95%CI: 0.58, 0.81, p-trend <0.001) was associated with lower mortality risk. Likewise, each quartile reflecting more frequent active bouts (Q4 vs. Q1 HR: 0.58, 95%CI: 0.49, 0.70, p-trend <0.001) was associated with lower mortality risk. Results for the sedentary bouts model remained significant after adjusting for total minutes per day in sedentary behavior (Q4 vs. Q1 HR: 0.63, 95%CI: 0.61, 0.86, p-trend=0.001). The association between active bout frequency with mortality was attenuated after adjusting for total minutes per day active. Regardless of total time spent sedentary, reducing duration of sedentary bouts with more frequent and shorter bouts may be a simple and feasible method to delay mortality risk among community-dwelling older men.

Levels and patterns of physical activity and sedentary behavior in adults with and without visual impairment

BackgroundLimited data are available on objectively measured physical activity (PA) and sedentary behavior (SB) among adults with and without visual impairment (VI). ObjectiveTo compare PA and SB levels and patterns in adults with and without VI and to examine how these differ based on sex and day of the week. MethodsThirty-two participants with VI and 32 participants without VI participated in this cross-sectional study. PA and SB were assessed using GT3X ActiGraph accelerometers during waking hours for 7 days, and variables were examined in terms of disability group, sex, and day of the week. Nonparametric Mann–Whitney U test and Wilcoxon signed-rank test were used, and significance was set at p < 0.05. ResultsPA did not differ in terms of sex or day of the week in participants with VI. The PA of participants without VI was significantly higher for men than it was for women and was significantly higher during weekdays than on weekend days. Total sedentary time and the duration of SB breaks were significantly longer for female participants with VI than for those without VI. The number of sedentary bouts lasting ≥10 min during weekend days was significantly higher for participants with VI than for those without VI. ConclusionsMost adults with and without VI did not meet the recommended levels of daily PA and spend a large portion of the day being sedentary. Interventions to enhance PA and reduce sedentary time in adults with and without VI are required.

Sedentary Behaviour Intervention as a Personalised Secondary Prevention Strategy (SIT LESS) for patients with coronary artery disease participating in cardiac rehabilitation: rationale and design of the SIT LESS randomised clinical trial

Patients with coronary artery disease (CAD) are more sedentary compared with the general population, but contemporary cardiac rehabilitation (CR) programmes do not specifically target sedentary behaviour (SB). We developed a...

Ecological Validity of Prolonged Sitting Studies: How Well Do They Represent Real-Life Sedentary Patterns? A Pilot Study

ABSTRACT Acute prolonged sitting studies have been frequently implemented to determine the physiological effect of sedentary time on vascular and metabolic health. The length of these laboratory-based prolonged sitting studies ranges from 1.5 to 6 h, with most being 3 h in duration. Whether or not these sitting durations reflect true habitual prolonged sitting patterns is unclear. The purpose of this pilot study was to examine the habitual sedentary patterns of a heterogeneous sample to inform the design of future acute laboratory-based sitting studies. Participants (n = 121; 48 females) wore an activPAL inclinometer on their thigh 24 h·d−1 for 6.5 ± 0.7 d. A customized LabVIEW program determined daily averages of waking hours spent standing versus sitting and/or laying. The number of prolonged sedentary bouts (e.g., number of sedentary bouts &gt;30 min) and the frequency of sedentary breaks (per waking hour) were also calculated. Overall, participants engaged in 9.4 ± 1.9 h·d−1 of sedentary time. Participants frequently engaged in sedentary bouts between 0.5 and 1.0 h (3.5 ± 1.1 bouts per day) and between 1 and 2 h (1.7 ± 0.8 bouts per day) in duration. By contrast, they rarely engaged in bouts &gt;2 h without interruption (i.e., once every ~5 d). Very few participants engaged in any prolonged sedentary bouts between 3 and 4 h (n = 25; 21%) or &gt;4 h (n = 6, 5%). Participants averaged 2.9 ± 0.7 sedentary breaks per hour (i.e., every ~21 min), with the majority (n = 83, 69%) breaking up their sitting time every 17–30 min (i.e., 2–3.5 breaks per hour). To maximize the ecological validity, our preliminary findings indicate that acute models of prolonged sitting should be 1–2 h in length and strategies to break up prolonged sitting implemented every 20–30 min. The results from this pilot study may be used to inform large epidemiological studies to characterize prolonged sitting patterns in a variety of populations to assist in translating findings from the laboratory to the habitual setting.

The Effect of a Physical Activity Coaching Intervention on Accelerometer-Measured Sedentary Behaviours in Insufficiently Physically Active Ambulatory Hospital Patients.

Little is known about the impact that physical activity (PA) coaching interventions have on sedentary behaviours. The aim of this study was to investigate if a coaching intervention that increases PA coincidentally influences objectively measured sedentary time in insufficiently physically active adults. We recruited 120 insufficiently physically active ambulatory hospital patients and randomized them to either receive a PA coaching intervention designed to increase objectively measured moderate-to-vigorous-intensity PA (MVPA) or be part of a control group. Participants wore an accelerometer for seven days at baseline, post-intervention (three months) and follow-up (nine months). Changes in the average length of sedentary bouts, proportion of time in sedentary behaviours and number of sedentary bouts were evaluated using mixed-model ANOVAs. At baseline, both groups undertook 67 ± 13 sedentary bouts and spent 69% ± 6% of their time in sedentary behaviours. Compared with control, the intervention group decreased the number of sedentary bouts by 24% and the proportion of time in sedentary behaviours by 7% (p < 0.001). Significant changes were not observed between the groups for average length of sedentary bouts. The PA intervention led to a decrease in the number of sedentary bouts and proportion of time in sedentary behaviours. Future research should investigate PA coaching interventions designed to target simultaneous changes in MVPA and sedentary behaviours.

Sedentary activity bout length was associated with BMI and waist circumference in Swedish children aged 5-7years.

This study examined the pattern of sedentary behaviour during the week and on weekends and associations with health outcomes among children aged 5-7years in Sweden. This cross-sectional study used data from 342 children, many of whom had at least one parent born outside the Nordic region. Physical activity and sedentary time were measured by accelerometry. A sedentary bout was defined as 1-4 and 5-9min. Diet, time in front of television or computer screen, sleep and physical activity behaviour were measured via parental reports, and anthropometric data by research staff. The number of sedentary bouts was higher on weekends than on weekdays. Compared to girls, boys had more 1-4min bouts on both weekdays and weekend days, and more 5-9min bouts on weekends. A higher number of 5-9min bouts was associated with a higher body mass index and waist circumference. This study showed an association between sedentary activity and weight status in children as young as 5-7years. Reducing time, especially longer bouts, spent in sedentary activities may encourage healthy weight development in children.

Objectively Measured Sedentary Levels and Bouts by Day Type in Australian Young Children.

This study aimed to understand whether a higher number of sedentary bouts (SED bouts) and higher levels of sedentary time (SED time) occur according to different day types (childcare days, nonchildcare weekdays, and weekends) in Australian toddlers (1-2.99y) and preschoolers (3-5.99y). The SED time and bouts were assessed using ActiGraph GT3X+ accelerometers. The sample was composed of 264 toddlers and 343 preschoolers. The SED bouts and time differences were calculated using linear mixed models. The toddlers' percentage of SED time was higher on nonchildcare days compared with childcare days (mean difference [MD] = 2.3; 95% confidence interval, 0.7 to 3.9). The toddlers had a higher number of 1- to 4-minute SED bouts on nonchildcare days compared with childcare days. The preschoolers presented higher percentages of SED time during nonchildcare days (MD = 3.1; 95% confidence interval, 1.6 to 4.5) and weekends (MD = 1.9; 95% confidence interval, 0.4 to 3.4) compared with childcare days. The preschoolers presented a higher number of SED bouts (1-4, 5-9, 10-19, and 20-30min) during nonchildcare days and weekends compared with childcare days. No SED times or bout differences were found between nonchildcare days and weekends, neither SED bouts >30minutes on toddlers nor on preschoolers. The SED time and bouts seem to be lower during childcare periods, which means that interventions to reduce sedentary time should consider targeting nonchildcare days and weekends.

Sedentary Behavior Levels And Patterns In Men And Women With Intellectual Disability

Adults with Intellectual Disability (ID) experience health disparities that may be attributable to high levels of sedentary behavior. The levels and weekly patterns of sedentary behavior among U.S. adults with ID have received little attention. PURPOSE: To examine levels and patterns of sedentary behavior and how these differ between sexes and weekdays and weekend days in adults with ID. METHODS: The sample included 52 adults with ID (25 men; age 45 ± 14 years) who wore an accelerometer (wGT3X-BT; Actigraph) on the hip for 7 days. Using valid days, we determined total sedentary time, percent of wear time spent sedentary, number and duration of sedentary bouts, and breaks in sedentary time. We examined sedentary bouts with thresholds of ≥1, ≥10, ≥30, ≥60 and ≥90 min and breaks for bouts ≥10 min. We used t-tests and 2×2 (sex by day) ANOVA to evaluate the effects of sex and day of the week. RESULTS: Total sedentary time did not differ between men and women (533 ± 139 and 496 ± 140 min·day-1, respectively; p = 0.35; for both sexes combined, 514 ± 139 min·day-1). Men and women with ID accumulated sedentary time mostly in short bouts <10 min in duration. There were no significant differences between men and women, except for duration of sedentary bouts ≥1 min which was longer for men than women for weekdays (6.45 ± 2.58 and 5.18 ± 1.09 min, respectively; p = 0.027) and for all days of the week combined (6.71 ± 2.62 and 5.29 ± 1.11 min, respectively; p = 0.017). Most variables did not differ between week and weekend days, except for: duration of sedentary bouts ≥1 min was longer during weekend than weekdays in women (5.5 ± 1.8 and 5.18 ± 1.07 min, respectively; p = 0.048); duration of sedentary bouts ≥60 min was longer during week than weekend days in men (56 ± 42 and 47 ± 44 min, respectively; p = 0.037); number of sedentary bouts ≥1 min was greater during weekdays than weekend days in men (87 ± 21 and 83 ± 25 bouts·day-1, respectively; p = 0.045); and duration of breaks was greater during the weekdays than weekend days in men (138 ± 126 and 81 ± 67 min, respectively; p <0.001). CONCLUSION: U.S. adults with ID spend a large portion of the day in sedentary behavior primarily of short bouts. There are small differences between sexes and between days of the week, suggesting near-uniform sedentary behavior levels and patterns for men and women with ID throughout the week.

Behavioral Conformity of Physical Activity and Sedentary Behavior in Older Couples with One Partner Suffering from End-Stage Osteoarthritis.

PurposeThe present study investigates behavioral conformity regarding physical activity (PA) and sedentary behavior (SB) in older couples where one partner suffers from osteoarthritis (OA). Hereby the question is addressed whether and to what extent the typical physical limitations of OA patients have negative effects on their partners.Patients and MethodsThe habitual PA and SB of end-stage osteoarthritis patients (n = 32, 52–81 years | n = 14 gonarthrosis, n = 18 coxarthrosis), their spouses (n = 32, 50–83 years) and control couples (n = 26 subjects, 52–78 years) were assessed by accelerometry. Besides individual results of accelerometry hourly couple-specific performance ratios were calculated for four parameters of PA (number of steps, vector magnitude (VM), metabolic rate (MET), and total time in moderate-to-vigorous PA (MVPA)) and two parameters of SB (number of sedentary bouts and total time of sedentary bouts per hour). Analyses of covariance were used to explore differences in hourly couple-specific performance ratios between couples affected by osteoarthritis and control couples.ResultsSignificant differences in PA were observed between the three groups, whereby the patients showed the lowest PA and the subjects of the control group the highest PA. In contrast to this, SB did not differ between the three groups. The hourly analyses of couple-specific performance ratios revealed significant differences between the target couples (patients and spouses) and the control couples for all parameters of PA. Thereby, the deviance in PA between the patients and their spouses was always smaller than in control couples and also decreased with age. The investigation of SB, on the other hand, revealed larger deviations between the patients and their spouses as compared to control couples and no changes with age.ConclusionThis study confirmed the known negative impact of osteoarthritis on the PA and SB of elderly patients. More important, however, was the finding that the patients’ spouses adapt to this poor health behavior and show reduced PA as well. Consequentially, spouses of OA patients should be considered as a risk group for inactivity-related diseases in old age. This should be considered in interventions that aim to use the individual support of spouses to increase the PA of OA patients.

Three distinct physical behavior types in fatigued patients with multiple sclerosis

BackgroundMultiple sclerosis often leads to fatigue and changes in physical behavior (PB). Changes in PB are often assumed as a consequence of fatigue, but effects of interventions that aim to reduce fatigue by improving PB are not sufficient. Since the heterogeneous nature of MS related symptoms, levels of PB of fatigued patients at the start of interventions might vary substantially. Better understanding of the variability by identification of PB subtypes in fatigued patients may help to develop more effective personalized rehabilitation programs in the future. This study aimed to identify PB subtypes in fatigued patients with multiple sclerosis based on multidimensional PB outcome measures.MethodsBaseline accelerometer (Actigraph) data, demographics and clinical characteristics of the TREFAMS-ACE participants (n = 212) were used for secondary analysis. All patients were ambulatory and diagnosed with severe fatigue based on a score of ≥35 on the fatigue subscale of the Checklist Individual Strength (CIS20r). Fifteen PB measures were used derived from 7 day measurements with an accelerometer. Principal component analysis was performed to define key outcome measures for PB and two-step cluster analysis was used to identify PB types.ResultsAnalysis revealed five key outcome measures: percentage sedentary behavior, total time in prolonged moderate-to-vigorous physical activity, number of sedentary bouts, and two types of change scores between day parts (morning, afternoon and evening). Based on these outcomes three valid PB clusters were derived.ConclusionsPatients with severe MS-related fatigue show three distinct and homogeneous PB subtypes. These PB subtypes, based on a unique set of PB outcome measures, may offer an opportunity to design more individually-tailored interventions in rehabilitation.Trial registrationClinical trial registration no ISRCTN 82353628, ISRCTN 69520623 and ISRCTN 58583714.

Changes in Sitting Time and Sitting Fragmentation after a Workplace Sedentary Behaviour Intervention.

Prolonged sedentary behaviour (SB) has shown to be detrimental to health. Nevertheless, population levels of SB are high and interventions to decrease SB are needed. This study aimed to explore the effect of a personalized intervention aimed at reducing SB and increasing breaks in SB among college employees. A pre-experimental study design was used. Participants (n = 36) were recruited at a college in Massachusetts, USA. SB was measured over 7 consecutive days using an activPAL3 accelerometer. Following baseline measures, all participants received a personalized SB consultation which focused on limiting bouts of SB >30 min, participants also received weekly follow-up e-mails. Post-intervention measures were taken after 16 weeks. Primary outcome variables were sedentary minutes/day and SB bouts >30 min. Differences between baseline and follow-up were analyzed using paired t-tests. The intervention did not change daily sedentary time (−0.48%; p > 0.05). The number of sedentary bouts >30 min decreased significantly by 0.52 bouts/day (p = 0.010). In this study, a personalized SB intervention was successful in reducing number of bouts >30 min of SB. However, daily sedentary time did not reduce significantly. These results indicate that personalized, consultation-based interventions may be effective if focused on a specific component of SB.

Physical Activity Patterns and Sedentary Behavior in Older Women With Urinary Incontinence: an Accelerometer-based Study

Objective physical activity data for women with urinary incontinence are lacking. We investigated the relationship between physical activity, sedentary behavior, and the severity of urinary symptoms in older community-dwelling women with urinary incontinence using accelerometers. This is a secondary analysis of a study that measured physical activity (step count, moderate-to-vigorous physical activity time) and sedentary behavior (percentage of sedentary time, number of sedentary bouts per day) using a triaxial accelerometer in older community-dwelling adult women not actively seeking treatment of their urinary symptoms. The relationship between urinary symptoms and physical activity variables was measured using linear regression. Our cohort of 35 community-dwelling women (median, age, 71 years) demonstrated low physical activity (median daily step count, 2168; range, 687-5205) and high sedentary behavior (median percentage of sedentary time, 74%; range, 54%-89%). Low step count was significantly associated with nocturia (P = 0.02). Shorter duration of moderate-to-vigorous physical activity time was significantly associated with nocturia (P = 0.001), nocturnal enuresis (P = 0.04), and greater use of incontinence products (P = 0.04). Greater percentage of time spent in sedentary behavior was also significantly associated with nocturia (P = 0.016). Low levels of physical activity are associated with greater nocturia and nocturnal enuresis. Sedentary behavior is a new construct that may be associated with lower urinary tract symptoms. Physical activity and sedentary behavior represent potential new targets for treating nocturnal urinary tract symptoms.

Sedentary Patterns In People with Intellectual Disability

INTRODUCTION: Adults and older adults with intellectual disabilities (ID) have low physical activity levels (PALs) and very little is known about the patterns of sedentary time (ST) among them. PURPOSE: To analyze ST patterns of adults and older adults with ID. METHODS: A group of 42 adults and 42 older adults with mild to severe ID were recruited. A health screening questionnaire was completed by each participant and/or legal guardian. Height and weight were obtained to calculate BMI. ST patterns were assessed with ActiGraph accelerometers for 7 consecutive days. RESULTS: Non-significant differences in ST throughout the week were observed. Non-significant differences between gender groups were found for ST. A significant difference was found for age groups where adults present a higher number of breaks per sedentary hour than older adults (P = 0.048) and the obese participants spent more time on SB than those participants with a normal BMI (P = 0.042). We also found that the number of bouts in SB per day increased in those participants with higher BMI values (P = 0.005). CONCLUSIONS: These groups of subjects with ID showed a high prevalence of ST (79,4% of monitoring time). Interestingly, when comparing age and/or gender groups, no differences were observed for ST. Our findings provide novel and valuable information to be considered in future interventions aiming to increase PAL and reduce ST. Well-designed interventions and preventive health strategies in this specific population are recommended. Partially supported by: MEC (Ref: DEP2012-35335) & AGAUR (Ref: 2013FI_B2 00091)Table 1: Descriptive characteristics of the participants.Table 2: Time in sedentary, percentage of sedentary behavior·day-1, number of sedentary bouts·day-1, and number of breaks per sedentary hour.

Sedentary behaviour is associated with increased long-term cardiovascular risk in patients with rheumatoid arthritis independently of moderate-to-vigorous physical activity

BackgroundRheumatoid Arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD). The physical dysfunction symptomatic of RA means people living with this disease spend large periods of the day sedentary, which may further elevate their risk of CVD. The primary aim of this study was to investigate relationships between objectively assessed sedentary behaviour patterns and light physical activity (LPA) with 10-year risk of CVD. Secondary aims were to explore the role of sedentary behaviour patterns and LPA for individual CVD risk factors and functional disability in RA. The extent to which associations were independent of moderate-to-vigorous physical activity (MVPA) engagement was also examined.MethodsBaseline data from a subsample of participants recruited to the Physical Activity in Rheumatoid Arthritis (PARA) study were used to answer current research questions. Sixty-one patients with RA (mean age (± SD) = 54.92 ± 12.39 years) provided a fasted blood sample and underwent physical assessments to evaluate factors associated with their cardiovascular health. Sedentary behaviour patterns (sedentary time, sedentary bouts, sedentary breaks), LPA and MVPA were measured via 7-days of accelerometry. Ten-year CVD risk was computed (Q-risk-score2), and functional disability determined via questionnaire.ResultsRegressions revealed significant positive associations between sedentary time and the number of sedentary bouts per day ≥20 min with 10-year CVD risk, with the reverse true for LPA participation. Associations were independent of MVPA engagement.ConclusionsPromoting LPA participation and restricting sedentary bouts to <20 min may attenuate long-term CVD risk in RA, independent of MVPA engagement.Trial registrationISRCTN04121489 (retrospectively registered 19/10/2012).

Sedentary behavior: Different types of operationalization influence outcome measures

IntroductionSedentary behavior (SB) influences health status independently of physical activity. The formal definition of SB is: “any waking behavior characterized by an energy expenditure ≤1.5 METs while in a sitting or reclining posture”. However, measuring SB mostly does not include both the intensity and postural component. The aim of this study was to quantify the effect of type of operationalization of SB on total sedentary time and the pattern of SB. Methods53 healthy subjects were measured 24h with a multi-sensor activity monitor that provides a valid one-second detection of body postures and movements and a calculated intensity measure. The SB outcome measures were: total sedentary time; number of sedentary bouts; mean bout length; fragmentation; and W-index. All outcomes were calculated for three types of operationalization of SB: 1) waking time in lying and sitting posture and below the sedentary intensity threshold (<0.016g comparable with Actigraph <150 counts, COMBI); 2) waking time in lying and sitting posture (POST); 3) waking time below the sedentary intensity threshold (<0.016g, INT). Outcome measures based on these three operationalizations were compared with repeated measures ANOVA. ResultsTotal sedentary time was significantly different (p<0.001) between all three conditions: 505.8 (113.85)min (COMBI), 593.2 (112.09)min (POST), and 565.5 (108.54)min (INT). Significant differences were also found for other outcome measures. ConclusionOur study shows that type of operationalization significantly affects SB outcome measures. Therefore, if SB is defined according to the formal definition, measurements must include both the intensity and postural component.

Measuring the Daily Activity of Lying Down, Sitting, Standing and Stepping of Obese Children Using the ActivPALTM Activity Monitor.

This study describes the patterns of objectively measured sitting, standing and stepping in obese children using the activPALTM and highlights possible differences in sedentary levels and patterns during weekdays and weekends. Sixty-five obese children, aged 9-11 years, were recruited from primary schools in Terengganu, Malaysia. Sitting, standing and stepping were objectively measured using an activPALTM accelerometer over a period of 4-7 days. Obese children spent an average of 69.6% of their day sitting/lying, 19.1% standing and 11.3% stepping. Weekdays and weekends differed significantly in total time spent sitting/lying, standing, stepping, step count, number of sedentary bouts and length of sedentary bouts (p < 0.05, respectively). Obese children spent a large proportion of their time sedentarily, and they spent more time sedentarily during weekends compared with weekdays. This study on sedentary behaviour patterns presents valuable information for designing and implementing strategies to decrease sedentary time among obese children, particularly during weekends.

The Association between Sleep Quality, Physical Activity, and Risk of Developing Metabolic Syndrome

Physical inactivity and poor sleep quality have been shown to increase the risk for Metabolic Syndrome (MetS) in middle-aged and older adults. High levels of sedentary time, independent of physical activity (PA) amount, has also shown a relationship. Whether these relationships manifest at an earlier age has not been well explored. PURPOSE: To determine the independent effects of sedentary time, sleep quality, and physical activity (PA) on risk factors for MetS in young adults. METHODS: 40 young adults (age 20.2±1.7; BMI 21.2±2.6) underwent waist circumference (WC) and blood pressure (BP) measurements. Fasted blood glucose, Low Density Lipoprotein (LDL), High Density Lipoprotein (HDL), and Triglycerides (TG) were also assessed (Cardiochek Portable Blood Test System). Objective PA and sleep were measured for 7 days with an Actigraph GT3X accelerometer. Pearson correlations examined the relationship between sedentary (number of sedentary bouts, time in sedentary bouts, number of sedentary breaks, time per sedentary break, and daily average sedentary time), sleep quality (sleep onset latency, sleep efficiency, time in bed, sleep time, wake after sleep onset, number of awakenings, and time per awakening), and PA (energy expenditure, step counts, and time spent in light, moderate, moderate-vigorous, vigorous, and very vigorous PA intensities) variables with MetS risk factors (WC, BP, LDL, HDL, TG). Stepwise linear regression was used to determine the best predictors for each MetS risk factor. RESULTS: Time per sedentary bout (TSB), time per awakening (TA), step counts (SC), and moderate-vigorous PA (MVPA) were determined to have the strongest correlation with MetS variables. SC and TSB were significant predictors of WC (R2= .41; p<0.01). TA was a significant predictor of systolic BP (R2 = 0.49; p<0.01) and total MetS risk factors (R2= 0.28; p=.002). SC was the only significant predictor of HDL (R2=0.13; p=0.025). CONCLUSION: Sedentary time, PA, and sleep quality are predictive of risk factors for MetS in young adults. Therefore, interventions to decrease sedentary time as well as improve PA and sleep quality should be implemented at younger ages as well as older.

Trajectories of objectively measured physical activity in free-living older men.

The steep decline in physical activity (PA) among the oldest old is not well understood; there is little information about the patterns of change in PA and sedentary behaviour (SB) in older people. Longitudinal data on objectively measured PA data can give insights about how PA and SB change with age. Men age 70-90 yr, from a United Kingdom population-based cohort wore a GT3X accelerometer over the hip annually on up to three occasions (56%, 50%, and 51% response rates) spanning 2 yr. Multilevel models were used to estimate change in activity. Men were grouped according to achieving ≥150 min·wk of MVPA in bouts of ≥10 min (current guidelines) at two or three time points. A total of 1419 ambulatory men had ≥600 min wear time on ≥3 d at ≥2 time points. At baseline, men took 4806 steps per day and spent 72.5% of their day in SB, 23.1% in light PA, and 4.1% in moderate-to-vigorous PA (MVPA). Mean change per year was -341 steps, +1.1% SB, -0.7% light PA, and -0.4% MVPA each day (all P < 0.001). A total of 76.3% (n = 1083) never met guidelines ("stable low"), 7.9% (n = 112) consistently met guidelines ("stable high"), 8.2% (n = 116) stopped meeting guidelines by the last occasion ("decreasers"), and 4.9% (n = 69) started meeting guidelines by the last occasion ("increasers"). "Decreasers" spent 69.3% of each day in SB at baseline, which increased by 2% per year (P < 0.005), light activity remained at 23.3% (change, -0.2% per year; P = 0.4), and total MVPA decreased from 7.1% by -1.7% per year, (P < 0.001). The number of sedentary bouts >30 min increased from 5.1 by 0.1 per year (P = 0.02). Among older adults, the steep decline in total PA occurred because of reductions in MVPA, while light PA is relatively spared and sedentary time and long sedentary bouts increase.