Environmental correlates of sedentary behaviors and physical activity in Chinese preschool children: A cross-sectional study

ObjectiveThis cross-sectional study examined environmental correlates of sedentary behavior (SB) and physical activity (PA) in preschool children in the urban area of Tianjin, China.MethodsData were collected from the Physical Activity and Health in Tianjin Chinese Children study, involving healthy children 3–6 years old and their families. In all children (n = 980), leisure-time SB (LTSB) and leisure-time PA (LTPA) were reported in min/day by parents. In a subgroup (n = 134), overall sedentary time, light PA, and moderate-to-vigorous PA (MVPA) were objectively measured using ActiGraph accelerometry (≥3 days, ≥10 h/day). Environmental correlates were collected using a questionnaire that included home and neighborhood characteristics (e.g., traffic safety, presence of physical activity facilities) and children's behaviors. Potential correlates were identified using linear regression analysis.ResultsMultiple linear regression analysis showed that “having grandparents as primary caregivers” (βs and 95% confidence intervals (95%CIs) for overall sedentary time: 29.7 (2.1–57.2); LTSB (ln): 0.19 (0.11–0.28)) and “having a television (for LTSB (ln): 0.13 (0.00–0.25)) or computer (for LTSB (ln): 0.13 (0.03–0.23)) in the child's bedroom” were both associated with higher SB. Furthermore, “having grandparents as primary caregivers” was associated with less MVPA (β (95%CI): ?7.6 (?14.1 to ?1.2)), and “active commuting to school by walking” correlated with more MVPA (β (95%CI): 9.8 (2.2–17.4)). The path model showed that “more neighborhood PA facilities close to home” was indirectly related to higher LTPA (ln), which was partly mediated by “outdoor play” (path coefficients (95%CI): 0.005 (0.002–0.008)) and “going to these facilities more often” (path coefficients (95%CI): 0.013 (0.008–0.018)). Traffic safety was not a correlate.ConclusionFamily structure and media exposure in the home maybe important factors in shaping preschoolers’ PA patterns. Built environmental correlates could indirectly influence preschoolers’ LTPA through parental help with engaging in active behaviors.     

Adverse associations of sedentary behavior with cancer incidence and all-cause mortality: A prospective cohort study

BackgroundInconsistent results have been reported in developed countries for relationships between sedentary behavior and cancer incidence and mortality, and evidence from the Chinese population is scarce. This study aimed to investigate such relationships in large Chinese population-based prospective cohorts and to explore the joint effect and interaction of sedentary behavior and moderate-to-vigorous physical activity (MVPA) on these relationships.MethodsWe included 95,319 Chinese adults without cancer from 3 large cohorts and assessed their sedentary behavior and physical activity with a unified questionnaire. Cancer incidence and mortality were confirmed by interviewing participants or their proxies and checking hospital records and death certificates. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) for cancer and mortality were estimated using Cox proportional hazards regression models.ResultsDuring 559,002 person-years of follow-up, 2388 cancer events, 1571 cancer deaths, and 4562 all-cause deaths were recorded. Sedentary behavior was associated with increased risk of developing cancer and deaths in a dose–response manner. The multivariable-adjusted HRs (95%CIs) were the following: HR = 1.16, 95%CI: 1.01‒1.33; HR = 1.24, 95%CI: 1.04‒1.48; and HR = 1.15, 95%CI: 1.04‒1.28 for cancer incidence, cancer mortality, and all-cause mortality, respectively, for those having ≥10 h/day of sedentary time compared with those having <6 h/day of sedentary time. Sedentary populations (≥10 h/day) developed cancer or died 4.09 years and 2.79 years earlier, respectively, at the index age of 50 years. Failure to achieve the recommended level of MVPA may further aggravate the adverse associations, with the highest cancer and mortality risks being observed among participants with both ≥10 h/day of sedentary time and <150 min/week of MVPA. Limitations of this study include the fact that physical activity information was obtained via questionnaire instead of objective measurement and that there were insufficient incident cases for the analysis of associations between sedentary behavior and site-specific cancers.ConclusionSedentary behavior was associated with an increased risk of cancer and all-cause mortality among Chinese adults, especially for those with ≥10 h/day of sedentary time. It is necessary to reduce sedentary time, in addition to increasing MVPA levels, for the prevention of cancer and premature death.     

Can physical activity eliminate the mortality risk associated with poor sleep? A 15-year follow-up of 341,248 MJ Cohort participants

BackgroundThis study examined the joint associations of sleep patterns and physical activity (PA) with all-cause, cardiovascular disease (CVD), and cancer mortality.MethodsA total of 341,248 adults (mean age = 39.7 years; men: 48.3%) were included in the study, with a 15-year follow-up. Participants reported sleep duration and disturbances (difficulty falling asleep, easily awakened, or use of sleeping medication). PA was classified into 4 levels: <7.5, 7.5–14.9, 15.0–29.9, and ≥30.0 metabolic equivalent hours per week (MET-h/week). To understand the joint associations of sleep patterns and PA with mortality, Cox proportional hazard models were conducted, with exposure variables combining sleep duration/disturbances and PA.ResultsCompared with the reference group (sleeping 6–8 h/day), individuals who slept >8 h/day had higher risk for all-cause mortality (hazard ratio (HR) = 1.307, 95% confidence interval (95%CI): 1.248–1.369), CVD mortality (HR = 1.298, 95%CI: 1.165–1.445), and cancer mortality (HR = 1.128, 95%CI: 1.042–1.220). Short sleep duration was not associated with mortality risk. Increased risk of all-cause and CVD mortality was found in participants who had difficulty falling asleep (HR = 1.120, 95%CI: 1.068–1.175; HR = 1.163, 95%CI: 1.038–1.304, respectively), and used sleeping medication (HR = 1.261, 95%CI: 1.159–1.372; HR = 1.335, 95%CI: 1.102–1.618, respectively) compared with those who slept well. Long sleep duration and sleep disturbances were not associated with risk of all-cause and CVD mortality among individuals achieving a PA level of ≥15 MET-h/week, and in particular among those achieving ≥30 MET-h/week.ConclusionLong sleep duration, difficulty falling asleep, and use of sleeping medication were related to a higher risk of death. Being physically active at a moderate intensity for 25–65 min/day eliminated these detrimental associations.     

The association of major patterns of physical activity,sedentary behavior and sleeping with mortality in older adults

Objective: To identify major patterns of physical activity (PA), sedentary behavior (SB) and sleeping (all self-reported), and their association with long-term mortality.

Methods: Cohort of 2,851 individuals aged ≥ 60 from Spain. Mortality was ascertain from 2003 up to July 2013. Patterns of PA, SB and sleeping were identified by factor analysis.

Results: During follow-up, 1,145 deaths occurred. The first pattern, named “sedentary and non-active pattern”, was characterized by long sleeping or lying time, and not doing even light PA (household chores or walking). The second pattern was named “active and non-sedentary pattern”, and was characterized long time devoted to vigorous activities, long walking time, and short seating time. Compared to those in the first quartile of the “sedentary and non-active pattern”, those in the highest quartile showed a 71% higher mortality (HR: 1.71; 95%CI: 1.42–2.07; p-trend:<0.001); it corresponds to being 6-year older. By contrast, being in the highest versus the lowest quartile of the “active and non-sedentary pattern” was associated with a 32% lower mortality (HR: 0.68: 0.57–0.82; p-trend:<0.001); it corresponds to being 4-year younger.

Conclusion: The “sedentary and non-active” pattern had a large impact on mortality. The “active and non-sedentary” pattern showed an opposite and slightly lower association.     

The association of grip strength with cardiovascular diseases and all-cause mortality in people with hypertension: Findings from the Prospective Urban Rural Epidemiology China Study

BackgroundBoth hypertension and grip strength (GS) are predictors of mortality and cardiovascular disease (CVD), but whether these risk factors interact to affect CVD and all-cause mortality is unknown. This study sought to investigate the associations of GS with the risk of major CVD incidence, CVD mortality, and all-cause mortality in patients with hypertension.MethodsGS was measured using a Jamar dynamometer (Sammons Preston, Bolingbrook, IL, USA) in participants aged 35–70 years from 12 provinces included in the Prospective Urban Rural Epidemiology China Study. Cox frailty proportional hazards models were used to examine the associations of GS and hypertension and the outcomes of all-cause mortality and CVD incidence/mortality.ResultsAmong 39,862 participants included in this study, 15,964 reported having hypertension, and 9095 had high GS at baseline. After a median follow-up of 8.9 years (interquartile range, 6.7–9.9 years), 1822 participants developed major CVD, and 1250 deaths occurred (388 as a result of CVD). Compared with normotensive participants with high GS, hypertensive patients with high GS had a higher risk of major CVD incidence (hazard ratio (HR) = 2.39; 95% confidence interval (95%CI): 1.86–3.06; p < 0.001) or CVD mortality (HR = 3.11; 95%CI: 1.59–6.06; p < 0.001) but did not have a significantly increased risk of all-cause mortality (HR = 1.24; 95%CI: 0.92–1.68; p = 0.159). These risks were further increased if hypertensive participants whose GS level was low (major CVD incidence, HR = 3.31, 95%CI: 2.60–4.22, p < 0.001; CVD mortality, HR = 4.99, 95%CI: 2.64–9.43, p < 0.001; and all-cause mortality, HR = 1.93, 95%CI: 1.47–2.53, p < 0.001).ConclusionThe present study demonstrates that low GS is associated with the highest risk of major CVD incidence, CVD mortality, and all-cause mortality among hypertensive patients. High levels of GS appear to mitigate long-term mortality risk among hypertensive patients.     

Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults: A prospective cohort study

PurposeThis study aimed to examine the associations of accelerometer-derived steps volume and intensity with hospitalizations and all-cause mortality in older adults.MethodsThis prospective cohort study involved 768 community-dwelling Spanish older adults (78.8 ± 4.9 years, mean ± SD; 53.9% females) from the Toledo Study for Healthy Aging (2012–2017). The number of steps per day and step cadence (steps/min) were derived from a hip-mounted accelerometer worn for at least 4 days at baseline. Participants were followed-up over a mean period of 3.1 years for hospitalization and 5.7 years for all-cause mortality. Cox proportional hazards regression models were used to estimate the individual and joint associations between daily steps and stepping intensity with hospitalizations and all-cause mortality.ResultsIncluded participants walked 5835 ± 3445 steps/day with an intensity of 7.3 ± 4.1 steps/min. After adjusting for age, sex, body mass index (BMI), education, income, marital status and comorbidities, higher step count (hazard ratio (HR) = 0.95, 95% confidence interval (95%CI: 0.90–1.00, and HR = 0.87, 95%CI: 0.81–0.95 per additional 1000 steps) and higher step intensity (HR = 0.95, 95%CI: 0.91–0.99, and HR = 0.89, 95%CI: 0.84–0.95 per each additional step/min) were associated with fewer hospitalizations and all-cause mortality risk, respectively. Compared to the group having low step volume and intensity, individuals in the group having high step volume and intensity had a lower risk of hospitalization (HR = 0.72, 95%CI: 0.52–0.98) and all-cause mortality (HR = 0.60, 95%CI: 0.37–0.98).ConclusionAmong older adults, both high step volume and step intensity were significantly associated with lower hospitalization and all-cause mortality risk. Increasing step volume and intensity may benefit older people.     

Movement behaviors and their association with depressive symptoms in Brazilian adolescents: A cross-sectional study

Background:Physical activity,sleep,and sedentary behaviors compose 24-h movement behaviors and have been independently associated with depressive symptoms.However,it is not clear whether it is the movement behavior itself or other contextual factors that are related to depressive symptoms.The objective of the present study was to examine the associations between self-reported and accelerometer-measured movement behaviors and depressive symptoms in adolescents.Methods:Cross-sectional data from 610 adolescents(14-18 years old)were used.Adolescents answered questions from the Center for Epidemiological Studies Depression scale and reported time spent watching videos,playing videogames,using social media,time spent in various physical activities,and daytime sleepiness.Wrist-worn accelerometers were used to measure sleep duration,sleep efficiency,sedentary time,and physical activity.Mixed-effects logistic regressions were used.Results:Almost half of the adolescents(48%)were classified as being at high risk for depression(score≥20).No significant associations were found between depressive symptoms and accelerometer-measured movement behaviors,self-reported non-sport physical activity,watching videos,and playing videogames.However,higher levels of self-reported total physical activity(odd ratio(OR)=0.92,95%confidence interval(95%CI):0.86-0.98)and volume of sports(OR=0.88,95%CI:0.79-0.97),in minutes,were associated with a lower risk of depression,while using social media for either 2.0-3.9 h/day(OR=1.77,95%CI:1.58-2.70)or>3.9 h/day(OR=1.67,95%CI:1.10-2.54),as well as higher levels of daytime sleepiness(OR=1.17,95%CI:1.12-1.22),were associated with a higher risk of depression.Conclusion:What adolescents do when they are active or sedentary may be more important than the time spent in the movement behaviors because it relates to depressive symptoms.Targeting daytime sleepiness,promoting sports,and limiting social media use may benefit adolescents.     

Cardiorespiratory fitness measured with cardiopulmonary exercise testing and mortality in patients with cardiovascular disease: A systematic review and meta-analysis

BackgroundCardiorespiratory fitness (CRF) is inversely associated with mortality in apparently healthy subjects and in some clinical populations, but evidence for the association between CRF and all-cause and/or cardiovascular disease (CVD) mortality in patients with established CVD is lacking. This study aimed to quantify this association.MethodsWe searched for prospective cohort studies that measured CRF with cardiopulmonary exercise testing in patients with CVD and that examined all-cause and CVD mortality with at least 6 months of follow-up. Pooled hazard ratios (HRs) were calculated using random-effect inverse-variance analyses.ResultsData were obtained from 21 studies and included 159,352 patients diagnosed with CVD (38.1% female). Pooled HRs for all-cause and CVD mortality comparing the highest vs. lowest category of CRF were 0.42 (95% confidence interval (95%CI): 0.28–0.61) and 0.27 (95%CI: 0.16–0.48), respectively. Pooled HRs per 1 metabolic equivalent (1-MET) increment were significant for all-cause mortality (HR = 0.81; 95%CI: 0.74–0.88) but not for CVD mortality (HR = 0.75; 95%CI: 0.48–1.18). Coronary artery disease patients with high CRF had a lower risk of all-cause mortality (HR = 0.32; 95%CI: 0.26–0.41) than did their unfit counterparts. Each 1-MET increase was associated with lower all-cause mortality risk among coronary artery disease patients (HR = 0.83; 95%CI: 0.76–0.91) but not lower among those with heart failure (HR = 0.69; 95%CI: 0.36–1.32).ConclusionA better CRF was associated with lower risk of all-cause mortality and CVD. This study supports the use of CRF as a powerful predictor of mortality in this population.     

Stair climbing,genetic predisposition,and the risk of incident type 2 diabetes: A large population-based prospective cohort study

BackgroundCross-sectional evidence and small-scale trials suggest positive effects of stair climbing on cardiometabolic disease and glucose regulation. However, few studies have examined the long-term association between stair climbing and the incidence of type 2 diabetes (T2D). We aimed to prospectively evaluate the association of stair climbing with T2D and assess modifications by genetic predisposition to T2D.MethodsWe included 451,699 adults (mean age = 56.3 ± 8.1 years, mean ± SD; 55.2% females) without T2D at baseline in the UK Biobank and followed up to March 31, 2021. Stair climbing information was collected through the touchscreen questionnaire. Genetic risk score for T2D consisted of 424 single nucleotide polymorphisms.ResultsDuring a median follow up of 12.1 years, 14,896 T2D cases were documented. Compared with participants who reported no stair climbing, those who climbed stairs regularly had a lower risk of incident T2D (10–50 steps/day: hazard ratio (HR) = 0.95, 95% confidence interval (95%CI): 0.89–1.00; 60–100 steps/day: HR = 0.92, 95%CI: 0.87–0.98; 110–150 steps/day: HR = 0.86, 95%CI: 0.80–0.91; >150 steps/day: HR = 0.93, 95%CI: 0.87–0.99, p for trend = 0.0007). We observed a significant interaction between stair climbing and genetic risk score on the subsequent T2D risk (p for interaction = 0.0004), where the risk of T2D showed a downward trend in subjects with low genetic risk and those who reported stair climbing activity of 110–150 steps/day appeared to have the lowest overall T2D risk among those with intermediate to high genetic risk.ConclusionA higher number of stairs climbed at home was associated with lower T2D incidence risk, especially among individuals with a low genetic predisposition to T2D. These findings highlight that stair climbing, as incidental physical activity, offers a simple and low-cost complement to public health interventions for T2D prevention.     

Cardiorespiratory fitness and cancer in women: A prospective pilot study

PurposeTo assess the association between cardiorespiratory fitness (CRF) and the incidence and mortality from cancer in women, and to evaluate the potential public health implications for cancer prevention.MethodsMaximal exercise testing was performed in a pilot cohort of 184 women (59.3 ± 15.2 years) who were followed for 12.0 ± 6.9 years. Cox hazard models adjusted for established cancer risk factors and accounting for competing events were analyzed for all-type cancer incidence and mortality from cancer. Population-attributable risks and exposure impact number were determined for low CRF (<5 metabolic equivalents (METs)) as a risk factor.ResultsDuring the follow-up, 11.4% of the participants were diagnosed with cancer and 3.2% died from cancer. CRF was inversely and independently associated with cancer outcomes. For every 1-metabolic equivalent increase in CRF, there was a 20% decrease in the risk of cancer incidence (hazard ratio (HR) = 0.80, 95% confidence interval (CI): 0.69–0.92; p = 0.001) and a 26% reduction in risk of cancer mortality (HR = 0.74, 95%CI: 0.61–0.90; p = 0.002). The population-attributable risks of low CRF were 11.6% and 14% for incidence and mortality of cancer, respectively, and the respective exposure impact numbers were 8 and 20.ConclusionGreater CRF was independently associated with a lower risk of incidence and mortality from cancer in women. Screening for low CRF as a cancer risk factor and referring unfit individuals to a supervised exercise program could be a public health strategy for cancer prevention in middle-age women.     

Compensatory changes in physical activity and sedentary time in children and adolescents with cystic fibrosis

Physical activity (PA) is a key element in Cystic Fibrosis (CF) treatment strategies, yet little is known as to whether activity compensation occurs. This study examined whether PA and/or sedentary time on one day were temporally associated with time spent in these intensities the following day in youth with CF. Time spent sedentary and in different PA intensities were objectively-measured for seven consecutive days in 50 youth (22 boys; 12.0 ± 2.7 years); 25 with mild-to-moderate CF and 25 age- and sex-matched controls. Multilevel analyses (day and child) were conducted using generalised linear latent and mixed models. On any given day, every additional 10 minutes spent in sedentary time or moderate-to-vigorous physical activity (MVPA) were associated with 1.9 (95%CI: ?3.6 to ?1.2) and 12.4 (95%CI: ?22.1 to ?2.9) minutes less sedentary time the following day, respectively. These temporal associations were also observed when split by group (3.1 vs. 1.9 minutes for healthy and CF, respectively). These findings indicate that youth do not compensate their PA, irrespective of disease status, between days, but may compensate their sedentary time between days. Experimental studies are warranted to fully elucidate whether compensatory responses to PA and sedentary time occur, which is fundamental for informing PA promotion strategies.     

Associations between aerobic and muscle-strengthening physical activity,sleep duration,and risk of all-cause mortality: A prospective cohort study of 282,473 U.S. adults

PurposeTo examine the joint associations between meeting guidelines for physical activity (PA) and sleep duration and all-cause mortality risk among adults.MethodsParticipants were adults (n = 282,473) aged 18–84 years who participated in the 2004–2014 U.S. National Health Interview Survey. Mortality status was ascertained using the National Death Index through December 2015. Self-reported PA (Active: meeting both aerobic (AER) and muscle-strengthening (MSA) guidelines, AER only (AER), MSA only (MSA), or not meeting either AER or MSA (Inactive)) and sleep duration (Short, recommended (Rec), or Long) were classified according to guidelines, and 12 PA–sleep categories were derived. Adjusted hazard ratios and 95% confidence intervals (95%CIs) for all-cause mortality risk were estimated using Cox proportional hazards regression models.ResultsA total of 282,473 participants (55% females) were included; 18,793 deaths (6.7%) occurred over an average follow-up of 5.4 years. Relative to the Active-Rec group, all other PA-sleep groups were associated with increased mortality risk except for the Active-Short group (hazard ratio = 1.08; 95%CI: 0.92–1.26). The combination of long sleep with either MSA or Inactive appeared to be synergistic. For a given sleep duration, mortality risk progressively increased among participants classified as AER, MSA, and Inactive. Within each activity level, the mortality risk was greatest among adults with long sleep.ConclusionRelative to adults meeting guidelines for both PA and sleep duration, adults who failed to meet guidelines for both AER and muscle strengthening PA and who also failed to meet sleep duration guidelines had elevated all-cause mortality risks. These results support interventions targeting both PA and sleep duration to reduce mortality risk.     

Prospective associations between joint categories of physical activity and insomnia symptoms with onset of poor mental health in a population-based cohort

BackgroundPhysical inactivity and insomnia symptoms are independently associated with increased risk of depression and anxiety; however, few studies jointly examine these risk factors. This study aimed to prospectively examine the joint association of physical activity (PA) and insomnia symptoms with onset of poor mental health in adults.MethodsParticipants from the 2013 to 2018 annual waves of the Household Income and Labour Dynamics in Australia panel study who had good mental health (Mental Health Inventory-5 >54) in 2013, and who completed at least 1 follow-up survey (2014–2018), were included (n = 10,977). Poor mental health (Mental Health Inventory-5 ≤ 54) was assessed annually. Baseline (2013) PA was classified as high/moderate/low, and insomnia symptoms (i.e., trouble sleeping) were classified as no insomnia symptoms/insomnia symptoms, with 6 mutually exclusive PA-insomnia symptom groups derived. Associations of PA–insomnia symptom groups with onset of poor mental health were examined using discrete-time proportional-hazards logit-hazard models.ResultsThere were 2322 new cases of poor mental health (21.2%). Relative to the high PA/no insomnia symptoms group, there were higher odds (odds ratio and 95% confidence interval (95%CI)) of poor mental health among the high PA/insomnia symptoms (OR = 1.87, 95%CI: 1.57–2.23), moderate PA/insomnia symptoms (OR = 1.93, 95%CI: 1.61–2.31), low PA/insomnia symptoms (OR = 2.33, 95%CI: 1.96–2.78), and low PA/no insomnia symptoms (OR = 1.14, 95%CI: 1.01–1.29) groups. Any level of PA combined with insomnia symptoms was associated with increased odds of poor mental health, with the odds increasing as PA decreased.ConclusionThese findings highlight the potential benefit of interventions targeting both PA and insomnia symptoms for promoting mental health.     

Segmented sedentary time and physical activity patterns throughout the week from wrist-worn ActiGraph GT3X+ accelerometers among children 7-12 years old

Background:This study examined the volume and patterns of physical activity(PA) and sedentary time(ST) across different segments of the week among boys and girls.Methods:A total of 188 children aged 7-12 years wore a wrist-mounted ActiGraph GT3 X+accelerometer for 7 days.Time spent in PA and ST was calculated using ActiLife software.The mean number of minutes of light PA,moderate PA,vigorous PA,moderate-to-vigorous PA(MVPA),and ST were calculated per weekday(before school,during school,and after school) and per weekend day(morning and afternoon-evening).Results:After school represented the greatest accumulation of ST compared with before school and during school segments.Boys engaged in225.4 min/day of ST(95% confidence interval(CI):216-235),and girls engaged in 222.2 min/day of ST(95%CI:213-231).During school,boys engaged in significantly more MVPA than girls(46.1 min/day(95%CI:44-48) vs.40.7 min/day(95%CI:39-43)).Across the whole weekday,boys participated in significantly more MVPA than girls(103.9 min/day(95%CI:99-109) vs.95.7 min/day(95%CI:90-101)).The weekend afternoon—evening segment represented the larger accumulation of ST,where boys were significantly more sedentary than girls(367.5 min/day(95%CI:353-382) vs.339.8 min/day(95%CI:325-355),respectively).Conclusion:Our findings suggest that children are highly sedentary and spend little of their time in school in MVPA,especially girls.Routine breaks in school elicit increases in light PA and MVPA.Future work should consider the use of more active breaks within school time to encourage PA and reduce ST.     

Mortality in relation to changes in physical activity in middle-aged to older Chinese: An 8-year follow-up of the Guangzhou Biobank Cohort Study

BackgroundPhysical activity (PA) is generally encouraged. Studies from developed countries in the West have shown that maintenance of adequate PA or increasing PA are associated with lower mortality risk. It is unclear whether these associations apply to an older Chinese population. Hence, we examined the changes in PA prospectively among a middle-aged and older Chinese population over an average of 4 years and explored their subsequent mortality risks.MethodsMetabolic equivalent scores of PA among participants in the Guangzhou Biobank Cohort Study were calculated. Participants were divided into 3 groups related to PA level, and changes in PA were classified into 9 categories. Information on vital status and causes of death from March 2008 to December 2012 (the first repeated examination) until December 31, 2017, was obtained via record linkage with the Death Registry.ResultsOf 18,104 participants aged 61.21 ± 6.85 years (mean ± SD), 1461 deaths occurred within 141,417 person-years. Compared to participants who maintained moderate PA, those who decreased PA from moderate or high levels to a low level had increased risks for all-cause mortality (hazard ratio (HR) = 1.47, 95% confidence interval (95%CI): 1.11–1.96). Participants who maintained a high level of PA (HR = 0.83, 95%CI: 0.70–0.98) or increased PA from low to high levels (HR = 0.71, 95%CI: 0.52–0.97) showed lower all-cause mortality risks. Those who maintained low PA levels showed a higher all-cause mortality risk, whereas those who increased their PA levels showed a non-significantly lower risk. Similar results were found for cardiovascular disease risk.ConclusionEven at an older age, maintaining a high PA level or increasing PA from low to high levels results in lower mortality risks, suggesting that substantial health benefits might be achieved by maintaining or increasing engagement in adequate levels of PA. The increased risk of maintaining a low PA level or decreasing PA to a low level warrants the attention of public health officials and clinicians.     

Frequent sit-to-stand transitions and several short standing periods measured by hip-worn accelerometer are associated with smaller waist circumference among adults

This cross-sectional study analysed the association of sedentary behaviour (SB) and standing with waist circumference. Finnish adults aged 30-75 years from a sub-sample of population-based Health 2011 Study used a hip-worn tri-axial accelerometer (Hookie AM20, Traxmeet, Ltd, Espoo, Finland) for seven days. Those 1405 participants (57% women) who used accelerometer at least four days, minimum of 10 hours/day, were included. SB and standing were analysed in 6s epochs using validated algorithm. Daily total time, daily number and accumulated time from bouts (30s–5min,30s–10min,30s–15min,30s 30min,>5min,>10min,>15min, >30min) as well as daily number of sit-to-stand transitions were determined. Waist circumference (cm) was measured in standardized way. Participants’ mean age was 52 years (SD 12.2). Mean waist circumference was 97cm (SD 12.3) in men and 87cm (SD 12.7) in women. According to multivariable stepwise linear regression analysis, sit-to-stand transitions [standardised regression coefficient (β)= -0.14, 95%CI -0.20 to -0.09], standing bouts of 30s–5min (β= -0.21, 95%CI -0.26 to -0.15) and number of 30s-30min SB bouts (β=0.12, 95%CI 0.06 to 0.17) were most strongly associated with waist circumference. Besides assessing total SB time, future studies should assess also different bout lengths of SB and sit-to-stand transitions and standing times should be assessed separately.     

Physical activity and chronic back conditions: A population-based pooled study of 60,134 adults

BackgroundLittle is known about the association between different types of physical activity (PA) and chronic back conditions (CBCs) at the population level. We investigated the association between levels of total and type-specific PA participation and CBCs.MethodsThe sample comprised 60,134 adults aged ≥16 years who participated in the Health Survey for England and Scottish Health Survey from 1994 to 2008. Multiple logistic regression models, adjusted for potential confounders, were used to examine the association between total and type-specific PA volume (walking, domestic activity, sport/exercise, cycling, football/rugby, running/jogging, manual work, and housework) and the prevalence of CBCs.ResultsWe found an inverse association between total PA volume and prevalence of CBCs. Compared with inactive participants, the fully adjusted odds ratio (OR) for very active participants (≥15 metabolic equivalent h/week) was 0.77 (95% confidence interval (CI): 0.69–0.85). Participants reporting ≥300 min/week of moderate-intensity activity and ≥75 min/week of vigorous-intensity activity had 24% (95%CI: 6%–39%) and 21% (95%CI: 11%–30%) lower odds of CBCs, respectively. Higher odds of CBCs were observed for participation in high-level manual domestic activity (OR = 1.22; 95%CI: 1.00–1.48). Sport/exercise was associated with CBCs in a less consistent manner (e.g., OR = 1.18 (95%CI: 1.06–1.32) for low levels and OR = 0.82 (95%CI: 0.72–0.93) for high levels of sport/exercise).ConclusionPA volume is inversely associated with the prevalence of CBCs.     

Cardiorespiratory fitness,white blood cell count,and mortality in men and women

BackgroundWe examined the associations of cardiorespiratory fitness (CRF) and white blood cell count (WBC) with mortality outcomes.MethodsA total of 52,056 apparently healthy adults completed a comprehensive health examination, including a maximal treadmill test and blood chemistry analyses. CRF was categorized as high, moderate, or low by age and sex; WBC was categorized as sex-specific quartiles.ResultsDuring 17.8 ± 9.5 years (mean ± SD) of follow-up, a total of 4088 deaths occurred. When regressed jointly, significantly decreased all-cause mortality across CRF categories was observed within each quartile of WBC in men. Within WBC Quartile 1, all-cause mortality hazard ratios (HRs) with a 95% confidence interval (95%CI) were 1.0 (referent), 1.29 (95%CI: 1.06?1.57), and 2.03 (95%CI: 1.42?2.92) for high, moderate, and low CRF categories, respectively (p for trend < 0.001). Similar trends were observed in the remaining 3 quartiles. With the exception of cardiovascular disease (CVD) mortality within Quartile 1 (p for trend = 0.743), there were also similar trends across CRF categories within WBC quartiles in men for both CVD and cancer mortality (p for trend < 0.01 for all). For women, there were no significant trends across CRF categories for mortality outcomes within Quartiles 1–3. However, we observed significantly decreased all-cause mortality across CRF categories within WBC Quartile 4 (HR = 1.05 (95%CI: 0.76?1.44), HR = 1.63 (95%CI:1.20?2.21), and HR = 1.87 (95%CI:1.29?2.69) for high, moderate, and low CRF, respectively (p for trend = 0.002)). Similar trends in women were observed for CVD and cancer mortality within WBC Quartile 4 only.ConclusionThere are strong joint associations between CRF, WBC, and all-cause, CVD, and cancer mortality in men; these associations are less consistent in women.     

Environmental correlates of total and domain-specific sedentary behaviour in young people. The UP&DOWN study

This study investigated the associations between the characteristics of the nearby physical environment with the total and domain-specific leisure-time sedentary behaviour (SB) in young people. The study included 1578 youth (9–18 years) from the UP&DOWN study. Total leisure-time SB was objectively-assessed by accelerometers. Participants self-reported the time spent during leisure-time in different domains of SB (i.e. screen-based, educational-based, social-based, and other-based SB). Information regarding the basic characteristics of the house, the perceived neighbourhood environment, the amount of physical activity facilities, equipment and materials attainable at home, and the media equipment available at home and in the own bedroom was collected. Linear mixed models were performed, including school and city as random effects. The availability of yard was related to lower total SB and time spent surfing the Internet in boys, but not in girls. More favourable perceived neighbourhood environment was associated with lower total SB and time spent playing video games in girls, but not in boys. The amount of physical activity materials at home was negatively associated with screen-based SB, while the availability of a computer in the own bedroom was positively related to the time spent surfing the Internet in boys and girls. The number of televisions at home and having a computer in the own bedroom was associated with lower time in educational-based SB in boys and girls, respectively. Increasing the number of PA materials at home and decreasing the number of TVs at home and the availability of a computer in the bedroom could improve SB profiles of youth.     

A mixed-studies systematic review and meta-analysis of school-based interventions to promote physical activity and/or reduce sedentary time in children

PurposeThe aim of this mixed-studies systematic review was to ascertain the effectiveness of school-based interventions in increasing physical activity (PA) and/or reducing sedentary time (ST) in children aged 5–11 years, as well as to explore their effectiveness in relation to categories of the theory of expanded, extended, and enhanced opportunity (TEO).MethodsAdhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 5 databases were searched using predefined search terms. Following title and abstract screening of 1115 records, the removal of duplicates (n = 584) and articles that did not meet the inclusion criteria agreed to a priori (n = 419) resulted in 112 records that were full-text screened. Two independent reviewers subsequently used the mixed-methods appraisal tool to assess the methodological quality of 57 full-text studies that met the inclusion criteria after full-text screening. The interventions were summarised using the TIDierR checklist and TEO. The strength of evidence was determined using a 5-level rating system utilising a published decision tree.ResultsOverall evidence ratings for interventions implemented within school settings were: no evidence of effects on moderate-to-vigorous physical activity (MVPA) and inconclusive evidence of effects on sedentary time. In relation to the TEO, expansion of PA appeared to be the most promising intervention type for MVPA, with moderate evidence of effect, whereas extension and enhancement of PA opportunity demonstrated no evidence of effect. A critical issue of possible compensatory behavior was identified by analysis of intervention effect in relation to PA measurement duration; when studies measured changes in PA during the actual intervention, there was moderate evidence of effect, whereas those that measured changes in PA during the school day presented inconclusive evidence of effect, and those that measured changes in PA over a whole day yielded no evidence of effect. Two meta-analyses of those studies using a whole-day accelerometer measure for MVPA or ST showed a significant but moderate effect for MVPA (effect size = 0.51; 95% confidence interval (CI): 0.02–0.99) and a large but nonsignificant effect for ST (effect size = 1.15; 95%CI: –1.03 to 3.33); both meta-analyses demonstrated low precision, considerable inconsistency, and high heterogeneity.ConclusionThe findings have important implications for future intervention research in terms of intervention design, implementation, and evaluation.