Patterns and correlates of sedentary behaviour among people with multiple sclerosis: a cross-sectional study

High levels of sedentary behaviour are associated with poor health outcomes in people with multiple sclerosis (MS). Identifying modifiable correlates of sedentary behaviour for people with MS is essential to design effective intervention strategies to minimise sedentary time. This study aimed to quantify patterns and identify correlates of sedentary behaviour among adults with MS. Fatigue, self-efficacy, walking capability, the physical and psychological impact of MS, health-related quality of life, and participation and autonomy were assessed by questionnaire. Participants wore an activPAL monitor. Total (min/day), prolonged bouts (≥ 30 min) and breaks in sedentary time were calculated. Associations were examined using regression analysis adjusted for demographic and clinical confounders. Fifty-six adults with MS participated (mean ± SD age: 57.0 ± 9.25 years; 66% female). Self-efficacy for control over MS was associated with sedentary time (β = 0.16, 95% CI 0.01, 0.30). Self-efficacy in function maintenance (β = 0.02, 95% CI 0.00, 0.04), health-related quality of life (EuroQol-5D) (β = 31.60, 95% CI 7.25, 55.96), and the autonomy indoors subscale of the Impact on Participation and Autonomy Questionnaire (β = − 5.11, 95% CI − 9.74, − 0.485) were associated with breaks in sedentary time. Future studies should consider self-efficacy, health-related quality of life and participation and autonomy as potential components of interventions to reduce sedentary behaviour.

The Influence of Habitual Breaks in Sedentary Time on Cardiovagal Baroreflex Function

Sedentary time (ST) has recently been included in the 24-h activity guidelines. However, the impact of habitual sedentary patterns on autonomic cardiovascular regulation are unclear. We tested the hypothesis that more ST and fewer sedentary breaks were associated with lower cardiovagal baroreflex sensitivity. More frequent sedentary breaks, but not total ST, was independently and positively associated with vagally-mediated blood pressure control. Breaking up ST could be more important than total ST for cardiovascular health. Novelty: Breaks in sedentary time is an independent predictor of cardiovagal baroreflex sensitivity, with more frequent breaks associated with better vagally-mediated blood pressure regulation.

Volume and accumulation patterns of physical activity and sedentary time: longitudinal changes and tracking from early to late childhood

Background Physical activity (PA) decreases and sedentary time (SED) increases across childhood, with both behaviours tracking. However, no studies have examined how accumulation patterns of PA and SED (i.e., prolonged bouts, frequency of breaks in sedentary time) change and track over time. The aim of this study was to investigate longitudinal changes in and tracking of total volume and accumulation patterns of SED, light-intensity PA (LPA), moderate-intensity PA (MPA), vigorous-intensity PA (VPA) among boys and girls. Methods In 2008/09 (T1), children in HAPPY (3-5y; n = 758) in Melbourne, Australia wore ActiGraph GT1M accelerometers to objectively assess SED, LPA, MPA and VPA. This was repeated at age 6-8y (T2; n = 473) and 9-11y (T3; n = 478). Ten pattern variables were computed: bouts of ≥ 5-, ≥ 10-, ≥ 15- and ≥ 20-min for SED, ≥ 1- and ≥ 5-min for LPA, ≥ 1-min for MPA, ≥ 1- and ≥ 5-min for VPA, and breaks in SED (interruptions of > 25 counts 15 s− 1). Longitudinal mixed models examined changes from T1-3, controlling for T1 age. Generalized estimating equations assessed tracking over the three time points, controlling for T1 age and time between measurements. Analyses were stratified by sex. Results Total volume and bouts of SED and SED breaks increased, while total volume and bouts of LPA decreased for both sexes. There was a small decrease in total volume of MPA for girls, but time spent in ≥ 1-min bouts increased for both sexes. Total volume of VPA increased for both sexes, with time spent in ≥ 1-min bouts increasing for boys only. All volume and pattern variables tracked moderately for boys, except for all SED bouts ≥ 15-min, LPA bouts ≥ 5-min and MPA bouts ≥ 1-min (which tracked weakly). For girls, total SED and SED bouts ≥ 1-min tracked strongly, total volume of LPA, MPA and VPA, ≥ 5- and ≥ 10-min SED bouts, and ≥ 1-min LPA and MPA bouts tracked moderately, and SED breaks, all SED bouts ≥ 15 min, LPA bouts ≥ 5 min and all VPA bouts tracked weakly. Conclusions Patterns of SED and PA change from early to late childhood; with the exception of SED breaks and VPA, changes were detrimental. Total volumes and short bouts tended to track more strongly than longer bouts. Interventions to prevent declines in PA and increases in SED are important from early in life.

Agreement of Sedentary Behavior Metrics Derived From Hip- and Thigh-Worn Accelerometers Among Older Adults: With Implications for Studying Physical and Cognitive Health

Little is known about how sedentary behavior (SB) metrics derived from hip- and thigh-worn accelerometers agree for older adults. Thigh-worn activPAL (AP) micro monitors were concurrently worn with hip-worn ActiGraph (AG) GT3X+ accelerometers (with SB measured using the 100 counts per minute [cpm] cut point; AG100cpm) by 953 older adults (age 77 ± 6.6, 54% women) for 4–7 days. Device agreement for sedentary time and five SB pattern metrics was assessed using mean error and correlations. Logistic regression tested associations with four health outcomes using standardized (i.e., z scores) and unstandardized SB metrics. Mean errors (AP − AG100cpm) and 95% limits of agreement were: sedentary time −54.7 [−223.4, 113.9] min/day; time in 30+ min bouts 77.6 [−74.8, 230.1] min/day; mean bout duration 5.9 [0.5, 11.4] min; usual bout duration 15.2 [0.4, 30] min; breaks in sedentary time −35.4 [−63.1, −7.6] breaks/day; and alpha −.5 [−.6, −.4]. Respective Pearson correlations were: .66, .78, .73, .79, .51, and .40. Concordance correlations were: .57, .67, .40, .50, .14, and .02. The statistical significance and direction of associations were identical for AG100cpm and AP metrics in 46 of 48 tests, though significant differences in the magnitude of odds ratios were observed among 13 of 24 tests for unstandardized and five of 24 for standardized SB metrics. Caution is needed when interpreting SB metrics and associations with health from AG100cpm due to the tendency for it to overestimate breaks in sedentary time relative to AP. However, high correlations between AP and AG100cpm measures and similar standardized associations with health outcomes suggest that studies using AG100cpm are useful, though not ideal, for studying SB in older adults.

Breaking Sedentary Time Predicts Future Frailty in Inactive Older Adults: A Cross-Lagged Panel Model

Background Cross-sectional evidence exists on the beneficial effects of breaks in sedentary time (BST) on frailty in older adults. Nonetheless, the longitudinal nature of these associations is unknown. This study aimed to investigate the direction and temporal order of the association between accelerometer-derived BST and frailty over time in older adults. Methods This longitudinal study analyzed a total of 186 older adults aged 67–90 (76.7 ± 3.9 years; 52.7% females) from the Toledo Study for Healthy Aging over a 4-year period. Number of daily BST was measured by accelerometry. Frailty was assessed with the Frailty Trait Scale. Multiple cross-lagged panel models were used to test the temporal and reciprocal relationship between BST and frailty. Results For those physically inactive (n = 126), our analyses revealed a reciprocal inverse relationship between BST and frailty, such as higher initial BST predicted lower levels of later frailty (standardized regression coefficient [β] = −0.150, 95% confidence interval [CI] = −0.281, −0.018; p < .05); as well as initial lower frailty levels predicted higher future BST (β = −0.161, 95% CI = −0.310, −0.011; p < .05). Conversely, no significant pathway was found in the active participants (n = 60). Conclusions In physically inactive older adults, the relationship between BST and frailty is bidirectional, while in active individuals no associations were found. This investigation provides preliminary longitudinal evidence that breaking-up sedentary time more often reduces frailty in those older adults who do not meet physical activity recommendations. Targeting frequent BST may bring a feasible approach to decrease the burden of frailty among more at-risk inactive older adults.

Impact of free-living pattern of sedentary behaviour on intra-day glucose regulation in type 2 diabetes

Purpose To investigate how the pattern of sedentary behaviour affects intra-day glucose regulation in type 2 diabetes. Methods This intensive longitudinal study was conducted in 37 participants with type 2 diabetes (age, 62.8 ± 10.5 years). Glucose and sedentary behaviour/physical activity were assessed with a continuous glucose monitoring (Abbott FreeStyle Libre) and an activity monitor (activPAL3) for 14 days. Multiple regression models with generalised estimating equations (GEEs) approach were used to assess the associations of sedentary time and breaks in sedentary time with pre-breakfast glucose, pre-lunch glucose, pre-dinner glucose, post-breakfast glucose, post-lunch glucose, post-dinner glucose, bedtime glucose, the dawn phenomenon, time in target glucose range (TIR, glucose 3.9–10 mmol/L) and time above target glucose range (TAR, glucose > 10 mmol/L). Results Sedentary time was associated with higher pre-breakfast glucose (p = 0.001), pre-dinner glucose (p < 0.001), post-lunch glucose (p = 0.005), post-dinner glucose (p = 0.013) and the dawn phenomenon (p < 0.001). Breaks in sedentary time were associated with lower pre-breakfast glucose (p = 0.023), pre-dinner glucose (p = 0.023), post-breakfast glucose (p < 0.001) and the dawn phenomenon (p = 0.004). The association between sedentary time and less TIR (p = 0.022) and the association between breaks in sedentary time and more TIR (p = 0.001) were also observed. Conclusions Reducing sedentary time and promoting breaks in sedentary time could be clinically relevant to improve intra-day glucose regulation in type 2 diabetes.

Independent and Joint Associations of Sedentary Behavior and Physical Activity with Cardiometabolic Health Markers in the 1970 British Birth Cohort

ObjectiveTo examine the independent and joint associations thigh-worn accelerometry assessed sedentary time and moderate to vigorous physical activity with cardiometabolic health markers.DesignCross-sectional study embedded in the age-46 wave an established birth cohort, the 1970 British Birth Cohort.SettingPopulation-based sample from Great Britain (England, Scotland, and Wales).MethodsOutcome measures included: body mass index, waist-to-hip ratio, blood pressure, glycated hemoglobin, high-density lipoprotein cholesterol, total cholesterol, triglycerides, and c-reactive protein. Sedentary behavior and other physical activity exposures, recorded by a thigh-worn activPAL3 accelerometry, included: daily sedentary time, breaks in sedentary time, daily time spent in moderate-to-vigorous physical activity. Multiple linear regression analyses, multiple logistic regression analyses, and general linear models were conducted as applicable.Results4,634 participants were available for the final analysis. After adjusting for potential confounders and moderate-to-vigorous physical activity, daily sedentary time was positively associated with triglycerides (β=0.052 [0.015, 0.089]) and inversely associated with high-density lipoprotein cholesterol (β=-0.015 [-0.022, -0.010]). Daily prolonged sedentary time (≥ 60 minutes) was positively associated with both glycated hemoglobin and log-transformed c-reactive protein (β=0.240 [0.030, 0.440] and 0.026 [0.007, 0.045], respectively) and inversely associated with systolic blood pressure and high-density lipoprotein cholesterol (β=-0.450 [-0.760, -0.150] and -0.013 [-0.022, -0.003], respectively). After adjusting for potential confounders and daily sedentary time, daily breaks in sedentary time were inversely associated with glycated hemoglobin (β=-0.020 [-0.037, -0.003]), and positively associated with both triglycerides and systolic blood pressure (β=0.006 [0.002, 0.010] and 0.030 [0.002, 0.050], respectively). The joint associations of prolonged sedentary time and moderate-to-vigorous physical activity with the prevalence of diabetes were not statistically significant.ConclusionProlonged sedentary time (≥ 60 minutes) and daily breaks in sedentary time were deleteriously associated with glycated hemoglobin, although we found no evidence that there were joint moderate-to-vigorous physical activity and sitting associations.