Sitting time in different contexts in Austrian adolescents and association with weight status

To describe active and sedentary time in children with spina bifida and to compare their physical activity on weekdays versus weekends. In this exploratory cross-sectional study, data from 13 Canadian and 22 Dutch children with spina bifida (14 females, 21 males; mean age 10y 11mo, standard deviation [SD] 3y 6mo, range 5y 6mo-18y; Hoffer classification distribution: community [n=28], household [n=3], non-functional [n=3], and non-ambulator [n=1]) were analysed. Objective measures of physical activity and sedentary behaviour were obtained by using ActiGraph or Actiheart activity monitors. Data for the participants wearing the ActiGraph were compared with age- and sex-matched controls that were developing typically using independent-samples t-tests. Activity data collected on weekdays was compared to those on weekends. ActiGraph data demonstrated children with spina bifida spent more time sedentary (mean [SD] 49.5min/h [5.78]) and less time in moderate to vigorous physical activity (mean [SD] 2.33min/h [1.61]) compared with the typically developing group (mean [SD] 41.0min/h [5.76] and 5.46min/h [2.13], p=0.001 and p<0.001 respectively). For both ActiGraph- and Actiheart-derived data, physical activity and sedentary time were not significantly different between weekdays and weekends. Children with spina bifida have reduced levels of physical activity and increased sedentary behaviour, with no statistical differences seen between weekdays and weekends. Several methodological issues related to activity monitoring warrant consideration when choosing the appropriate method to quantify physical activity and sedentary behaviour. Reduced levels of physical activity and sedentary time were quantified in children with spina bifida. Objective quantification of physical behaviour in ambulatory and non-ambulatory school-aged children with spina bifida is possible.

Objective To explore the association of sedentary behavior and time with risk of metabolic syndrome (MS).Methods A total of 10 149 subjects were recruited from local residents aged ≥40 years old in Jiashan County by cluster-random sampling method.The data including physical activity,job,sedentary time,and sleep,etc.were collected.Height and body weight,waist circumference,blood pressure,blood glucose,blood lipid,etc.were determined.Logistic regression was used for correlation analysis.Results The prevalence of MS was 28.64％ in local residents over 40 years old in Jiashan.The rate of sedentary behavior in all subjects was 67.57％,with 3 h sedentary time on average.Compared with non-MS group,the rates of sedentary behavior and sedentary time were significantly higher in MS group (P＜0.01).Multivariate logistic regression analysis showed that sedentary behavior was independently associated with an increased risk of MS after adjustment for age,sex,body mass index (BMI),smoking,drinking,and sedentary time(OR=1.16,95％ CI 1.03-1.30,P=0.017).Increased sedentary time was associated with higher risks of hypertension,type 2 diabetes mellitus,and dyslipidemia (P ＜ 0.05 or P ＜ 0.01).Sedentary time ≥ 5 h/d independently increased the risk of MS (OR =1.15,95％ CI 1.01-1.31,P =0.034).Conclusions There is a high prevalence of MS in adults over 40 years old living in the eastern coastal rural area.MS and its related diseases are closely associated with sedentary behavior and its duration. Key words: Sedentary behaviors ; Metabolic syndrome ; Hypertension ; Diabetes mellitus, type 2 ; Dyslipidemia

To establish whether associations between sedentary behavior and cardiometabolic health differ when assessed by thigh-worn and waist-worn accelerometry. Participants were recruited from several areas in the United Kingdom. Sedentary behavior was assessed using the activPAL worn on the thigh and ActiGraph worn on the waist. Average total (TST), prolonged (bouts ≥30 min; PST) and breaks (BST) in sedentary time were calculated. Cardiometabolic health markers included: adiposity (body fat) and surrogate markers of adiposity ((waist circumference, body mass index [BMI]), lipids (total, low density lipoprotein, and high-density lipoprotein [HDL] cholesterol, triglycerides), blood pressure, and glucose (fasting, 2 h and glycated hemoglobin A1c). A clustered cardiometabolic risk score was calculated. Linear regression analysis examined the associations with cardiometabolic health. There were 1457 participants (mean age [± standard deviation], 59.38 ± 11.85 yr; 51.7% male; mean BMI, 30.19 ± 5.59 kg·m) included in the analyses. ActivPAL and ActiGraph sedentary variables were moderately correlated (0.416-0.511, P < 0.01); however, all variables were significantly different from each other (P < 0.05). Consistency was observed across devices in the direction and magnitude of associations of TST and PST with adiposity, surrogate markers of adiposity, HDL, triglycerides, and cardiometabolic risk score and for BST with adiposity, surrogate markers of adiposity, and cardiometabolic risk. Differences across devices were observed in associations of TST and PST with diastolic blood pressure, for TST with 2-h glucose and for BST with HDL. No other associations were observed for any other health marker for either device. Results suggest that associations with cardiometabolic health are largely comparable across the two common assessments of sedentary behavior but some small differences may exist for certain health markers.

Prior to the 1980s, very little thought was given to sedentary behaviors and how they may impact health. In 1985, the first study to investigate the relationship between a sedentary behavior, television viewing, and weight status was published by Dietz and Gortmaker [1]. In this study, the relationship between television viewing and weight status in children and adolescents was examined cross-sectionally and longitudinally, using data from the National Health Examination Survey. Results indicated that television viewing was positively related to the prevalence of obesity, both cross-sectionally and longitudinally. This investigation led to a growing body of research examining the mechanisms by which television watching impacted weight status and if reducing television watching could improve weight status in children. Outcomes from this area of research informed the development of the recommendation that screen time should be limited to ≤2 hours per day in children [2]. Initially, the term “sedentary” was used to describe behaviors that were not considered to meet energy expenditure levels equivalent to moderate-intensity physical activity. Additionally, attention was focused on sedentary behaviors occurring during leisure time, thus television viewing and recreational computer use were the sedentary behaviors that were predominantly reported in early investigations of sedentary behaviors. Since the 1980s, sedentary behaviors have become more clearly defined and are now classified by energy expenditure level, similar to the way that physical activities are classified. Sedentary behaviors are characterized by minimal movement and a very low level of energy expenditure (<1.5 metabolic equivalent units (METs)) similar to that which is required to sit quietly [3, 4]. Thus, sedentary pursuits are primarily sitting behaviors that occur in a variety of domains (i.e., leisure, occupation, transportation, and recreation) and include working/playing on the computer, driving a car, and watching television. While sedentary behaviors have been associated with deleterious health outcomes in children for almost thirty years, sedentary behaviors are now also associated with morbidity in adults. Recent observational epidemiological research indicates that the more time spent being sedentary, independent of time engaging in physical activity, the greater the risk of developing type 2 diabetes [5], cardiovascular disease [5, 6], metabolic syndrome [7], weight gain [8–10], and obesity [11, 12]. Furthermore, evidence suggests that sedentary behaviors are an independent risk factor for all-cause and cardiovascular-related mortality [5, 13–15]. There are many proposed mechanisms by which sedentary behaviors may negatively influence health. For television watching, it was initially proposed that watching television may reduce energy expenditure, by competing with time to engage in physical activity, and increase energy intake, by serving as a cue for eating [16–19]. However, there is growing evidence suggesting that engaging in increased amounts of sedentary behaviors can have adverse effects on health that are distinct from those related to insufficient physical activity [4, 14, 20, 21]. Experimental studies show that prolonged sitting and lack of contraction of lower limb muscles lead to metabolic abnormalities via suppressed action of muscle lipoprotein lipase and insulin, supporting a unique “inactivity physiology” paradigm [20, 22–25]. Thus, sedentary behaviors may influence health via pathways that are independent of both physical activity and food consumption. Traditionally, while sedentary behaviors are believed to influence health through energy balance behaviors, the potential distinct mechanism by which sedentary behaviors may negatively influence health suggests that sedentary behaviors should potentially be targeted independently from physical activity and dietary intake in interventions designed to reduce risk type 2 diabetes, cardiovascular disease, and metabolic syndrome. The purpose of this special issue is to explore some of the unresolved issues pertaining to sedentary behaviors, weight, and health and disease risk in children and adults. The papers in this special issue assist in broadening the understanding of the relationship between sedentary behaviors, weight, and health. The topics regarding sedentary behaviors addressed in this issue include assessment of sedentary behaviors, the relationship of sedentary behaviors with other health behaviors and outcomes, how energy expenditure during sedentary behaviors may be increased, and outcomes for interventions designed to reduce sedentary behaviors. If experimental studies verify that sedentary behaviors are related to health outcomes that are public health priorities, continued research is needed to understand the pathways by which sedentary behaviors negatively impact health and how sedentary time can be reduced. Additionally, as the types and amount of sedentary behavior engaged in may be different in children versus adults due to differences in how time is spent and choices made about leisure-time activities, future research should investigate sedentary behaviors across the lifespan. Hollie A. Raynor Dale S. Bond Patty S. Freedson Susan B. Sisson

This study examined the 1-yr test-retest reliability and criterion validity of sedentary time survey items in a subset of participants from a large, nationwide prospective cohort. Participants included 423 women and 290 men age 31 to 72 yr in the Cancer Prevention Study-3. Reliability was assessed by computing Spearman correlation coefficients between responses from prestudy and poststudy surveys. Validity was assessed by comparing survey-estimated sedentary time with a latent variable representing true sedentary time estimated from the 7-d diaries, accelerometry, and surveys through the method of triads. Sensitivity analyses were restricted to 566 participants with an average of 14+ h of diary and accelerometer data per day for 7 d per quarter. Reliability estimates for total sitting time were moderate or strong across all demographic strata (Spearman ρ ≥ 0.6), with significant differences by race (P = 0.01). Reliability estimates were strongest for the TV-related sedentary time item (Spearman ρ, 0.74; 95% confidence interval, 0.70-0.77). The overall validity coefficient (VC) for survey-assessed total sedentary time was 0.62 (95% confidence interval, 0.55-0.69), although VC varied by age group and activity level (P < 0.05). However, VC were similar across groups (P < 0.05) when restricting to highly compliant participants in a sensitivity analysis. The Cancer Prevention Study-3 sedentary behavior questionnaire has acceptable reliability and validity for ranking or categorizing participants according to sedentary time. Acceptable reliability and validity estimates persist across various demographic subgroups.

BackgroundEven when meeting guidelines for physical activity (PA), considerable sedentary time may be included. This study in primary school children investigated the relationships between objectively evaluated sedentary and PA times at different intensities using triaxial accelerometry that discriminated between ambulatory and non-ambulatory PA. The relationships between subjectively evaluated screen time (i.e. time spent viewing television and videos, playing electronic games, and using personal computers) and objectively evaluated sedentary and PA times were examined.MethodsObjectively evaluated sedentary and PA times were assessed for 7 consecutive days using a triaxial accelerometer (Active style Pro: HJA-350IT) in 426 first to sixth grade girls and boys. Metabolic equivalents [METs] were used to categorize the minutes of sedentary time (≤1.5 METs), light PA (LPA, 1.6–2.9 METs), moderate-to-vigorous PA (MVPA, ≥3.0 METs) and vigorous PA (VPA, ≥6.0 METs). The physical activity level (PAL) was calculated using the mean MET value. Subjectively evaluated screen time behaviors were self-reported by participants and parents acting together. The associations between PA and sedentary and screen time variables were examined using partial correlation analyses.ResultsAfter adjustment for age, body weight and wearing time, objectively evaluated sedentary time correlated strongly with non-ambulatory and total LPA and PAL, moderately with ambulatory LPA, non-ambulatory or total MVPA, and weakly with ambulatory MVPA, ambulatory, non-ambulatory or total VPA. Subjectively evaluated screen time was not associated significantly with objectively evaluated sedentary and PA times or PAL. On average, each reduction of 30 min in daily sedentary time was associated with 6 or 23 min more of MVPA or LPA, respectively.ConclusionsThese findings show that higher daily sedentary time may be compensated mainly by lower LPA, while the association between sedentary time and MVPA was moderate. Therefore, improving MVPA and reducing sedentary time are important in primary school children.

Objective To understand the status and influencing factors of adolescent sedentary behavior, and to provide a basis for further improving health education and health promotion measures. Method Using multi-stage sampling method survey of 2 186 secondary school students in two cities across the country with adolescent sedentary behavior-psychological scale, including the TTM theoretical model of adolescent sedentary time, sedentary stage of change, change strategy, decision-making balance and the current status of self-efficacy. Results The average sedentary time in the school day was (4.19±1.99) hours per day, average sedentary time in the holidays (4.13±1.68) hours per day, Teaching, the sedentary time region group(χ2=-2.14, P<0.05), gender group (χ2=-4.18, P<0.01)and grade group(χ2=-4.43, P<0.01) were statistically difference, the sedentary time in holidays has statistically difference in grade(χ2=-5.95, P<0.01). Sedentary behavior existed phase behavior change for middle school students, and mainly in the first stages of consciousness and awareness, middle school students in different stages of behavior of sedentary time, once upon a time consciousness stage to operation stage the sedentary time was on the decline, and the maintenance stage increased slightly.Different stages of sedentary behavior change strategy of middle school students, decision balance, self-efficacy scores were statistically significant, the influence of psychological factors on the sedentary time showed the trend that the score decreases from consciousness stage to the action stage and increases in the maintenance stage.The factors of sedentary time in teaching time including gender, grade, stage of behavior change, change strategy, decision balance negative effect, the influence factors of holiday sedentary time including the grade, stage of behavior change, decisional balance (positive and negative). Conclusion The adolescents sedentary behavior time is significantly higher than the standard sedentary time and in a preconscious stage large number of responses to juvenile sedentary behavior target health interventions to recognize that reducing sedentary behavior on health benefits. Key words: The trans-theortical model; Middle-school student; Sedentary behavior

Establishing appropriate physical activity and sedentary behaviours during early childhood is important to ensure children accrue the many associated health benefits. While physical activity levels have been reported as low within early learning programs, little research has explored the physical activity and sedentary time of Canadian preschoolers classified as overweight within these facilities. The purpose of this study was to compare objectively measured physical activity and sedentary time among preschoolers classified as overweight and nonoverweight in early learning programs. Direct assessment of physical activity and sedentary time of 216 preschool-aged children was collected via Actical accelerometers during early learning hours, while body mass index percentile was calculated based on preschoolers' objectively measured height and weight. Results of three 3-way ANOVAs suggest that rates of moderate to vigorous physical activity, total physical activity, and sedentary time (p > 0.05) did not significantly differ based on weight status, sex, and type of early learning facility. This study is one of few that has examined differences in overweight and nonoverweight preschoolers' sedentary time, and adds to the limited research exploring physical activity levels among overweight and nonoverweight preschoolers during early learning hours. Given the high rates of sedentary time reported, programming within early learning facilities is necessary to support preschoolers, regardless of weight status, to achieve increased physical activity levels and decreased sedentary time.

Although correlates of physical activity (PA) have been extensively examined in both children and adolescents who are typically developing, little is known about correlates of moderate to vigorous physical activity (MVPA) and sedentary time in adolescents with intellectual and developmental disabilities (IDD). Therefore, we examined intrapersonal, interpersonal and environmental factors and their association with device-based MVPA and sedentary time in adolescents with IDD. MVPA and sedentary time was assessed using a hip-worn ActiGraph model wGT3x-BT tri-axial accelerometer across a 7-day period in adolescents with IDD and one of their parents. Pearson and point-biserial correlations were calculated to inspect the associations of PA (MVPA, sedentary time) with intrapersonal factors (demographic characteristic, BMI, waist circumference, motor ability, muscle strength, grip strength, cardiovascular fitness and self-efficacy for PA), interpersonal factors (parent demographics, parent BMI, parent MVPA and sedentary time, family social support for PA, parent barriers and support for PA, parent's beliefs/attitudes towards PA and number of siblings), and environmental factors (meteorologic season and COVID-19). Ordinary least squares regression was used to estimate the unique contributions of key factors to PA after controlling for participants' age, sex, race, waist circumference and total wear time. Ninety-two adolescents (15.5±3.0years old, 21.7% non-White, 6.5% Hispanic, 56.5% female) provided valid accelerometer data. Average sedentary time was 494.6±136.4min/day and average MVPA was 19.8±24.2min/day. Age (r=0.27, P=0.01), diagnosis of congenital heart disease (r=-0.26, P=0.01) and parent sedentary time (r=0.30, P=0.01) were correlated with sedentary time. BMI (r=-0.24, P=0.03), waist circumference (r=-0.28, P=0.01), identifying as White (r=-0.23, P=0.03) and parent MVPA (r=0.56, P<0.001) were correlated with MVPA. After adjusting for the adolescent's age, sex, race, waist circumference, and total wear time, the association between parent and adolescent MVPA remained significant (b=0.55, P<0.01, partial η2 =0.11). The results of this study provide evidence that race, waist circumference and parental MVPA may influence the amount of MVPA in adolescents with IDD. The limited available information and the potential health benefits of increased MVPA highlight the need to evaluate the effectiveness of multi-component interventions targeting both intrapersonal and interpersonal levels to promote increased PA in adolescents with IDD.

Medical Hazards of Prolonged Sitting

BackgroundEvidence is sparse about whether body weight categories in adolescents are associated with differences in pediatric HRQoL rated by adolescents and parents. Additionally, it is unknown whether HRQoL rated by individuals with different body mass index (BMI) weight categories is psychometrically comparable. This study aimed to assess whether difference in pediatric HRQoL rated by adolescents and their parents was explained by BMI weight status, and to test measurement properties of HRQoL items related to weight categories using differential item functioning (DIF) methodology. DIF refers to the situation when the individuals across subgroups rate an item differently (e.g., item score three by one subgroup and four by another) given the same underlying construct.MethodsA cross-sectional study utilizing a sample of parents (n = 323) and their adolescents aged 15–18 years old (n = 323) who enrolled in Florida’s Medicaid. Adolescent self-reports and parent proxy-reports of the Pediatric Quality of Life Inventory was adopted to measure pediatric HRQoL. We classified body weight categories as normal weight, overweight, and obesity. A Multiple Indicator Multiple Cause (MIMIC) method was used to assess DIF associated with BMI weight status, especially testing the disparity in the parameters of different weight categories (reference: lower weight category) associated with a response to a HRQoL item conditioning on the same underlying HRQoL. DIF analyses were conducted by adolescent self-reports and parent proxy-reports.ResultsParents reported lower pediatric HRQoL across all domains than adolescents did. Excess body weight (combined overweight and obese) was significantly associated with a greater discrepancy in the rating of emotional and total functioning between adolescents and parents (p < 0.05). DIF associated with BMI weight categories was identified by two items in adolescent self-reports and five items in parent proxy-reports.ConclusionsAdolescents’ BMI weight categories significantly contribute to a difference in the rating of pediatric HRQoL by adolescents and parents.

Sedentary behaviour in office workers: correlates and interventions

To understand the features of sedentary behavior of Chinese children and adolescents and its relationship with poor visual acuity, a self-administered "Questionnaire on Sedentary Behavior of Children and Adolescents" was used to survey 4,203 students in grades 4-12 in six administrative regions of China. (1) The average time spent in sedentary behaviors (SB) of Chinese children and adolescents was about 8.1 h per day, of which the academic sedentary time was the longest, accounting for 79.2% of total sedentary time. The total time spent on SB and the time spent on studying SB were more in the upper grades and less in screen SB and cultural leisure SB, respectively. There were significant sex differences in total SB time (p < 0.05) and weekend sedentary behaviors time (SB-WD) (p < 0.01) among Chinese children and adolescents, with girls being more likely to be higher than boys. There were also significant differences in sedentary time across different regions (p < 0.05), and the longest total sedentary time in East China. (2) Reduction parents' sedentary time and limitation of sedentary behaviors and the use of electronics among children and adolescents can effectively reduce sedentary time among Chinese children and adolescents. (3) Sedentary time was significantly higher in children and adolescents with poor vision than in those with normal vision (p < 0.01), and study SB and screen SB were important independent factors affecting vision. (4) Timing of breaks in SB can play a positive role in promoting vision health. There were significant grade, sex, and regional differences in the SB of Chinese children and adolescents, and sedentary time was strongly related to the prevalence of poor vision detection rate.

The Fat-mass and obesity-associated-gene (FTO gene) and sedentary behavior time are associated with obesity. However, whether sedentary behavior time can modify the genetic predisposition to obesity in the Chilean population is unknown. Therefore, this study investigated the association between sedentary behavior, adiposity markers, and the FTO gene. This cross-sectional study included 409 participants from the Genes, Environment, Diabetes, and Obesity (GENADIO) study. Adiposity markers studied included body weight, body mass index (BMI), waist circumference (WC), and fat mass. Sedentary behaviors were measured using accelerometers. Using multiple regression, we evaluated the interaction between sedentary behaviors and the FTO gene (rs9939609) on adiposity markers. Sedentary behaviors and the FTO genotype were positively associated with higher body weight, BMI, WC, and fat mass. However, the association between time of sedentary behavior and adiposity markers was higher in carriers of the risk variant for the FTO gene. For each hour of increment in sedentary behaviors, body weight increases by 1.36 kg ([95% CI: 0.27; 2.46], p = 0.015) and 2.95 kg ([95%CI: 1.24; 4.65], p = 0.001) in non-risk carriers (TT) versus risk carriers (AA), respectively. We observed similar results for WC, BMI, and body fat, but the interaction was significant only for WC. The association between sedentary behaviors and adiposity markers, especially body weight and WC, is higher in individuals who carry the risk variant of the FTO gene.

Correlates of Physical Activity and Sedentary Behaviors Among Overweight Hispanic School-aged Children