Association of sitting time and breaks in sitting with muscle mass, strength, function, and inflammation in community-dwelling older adults

Are accelerometer-measured sitting and physical activity times associated with muscle mass and strength in healthy young adults in the UAE?

Background

A high prevalence of obesity, sedentary behavior, and physical inactivity could affect muscle mass and strength in young adults in the United Arab Emirates (UAE). Therefore, we investigated the association of sex, body mass index (BMI), and accelerometer-measured sitting and physical activity (PA) times with skeletal muscle mass index (SMI), hand grip, and thigh muscle strength in healthy young adults in the UAE.

Methods

In this cross-sectional study, 156 healthy young adults (age 21.68 ± 3.01 years, BMI 25.40 ± 4.79 kg/m2, 52.6 % women) were included. BMI and muscle mass were recorded using a bioelectrical impedance analyzer. Maximum hand grip strength and thigh muscle torque were assessed using the Jamar-smart hand-dynamometer and Biodex System-4-Pro, respectively. Participants wore a triaxial Fibion accelerometer on their anterior thigh for >10 h per day for 4-7 days to measure their sitting and PA times. Multiple linear regression analyses were used.

Results

Participants spent most of their time sitting (11.37 ± 1.10 h), followed by standing (2.92 ± 0.86 h), walking (1.58 ± 0.55 h), and vigorous intensity PA (4.79 ± 5.85 min) per 16-h day. Sex (p < 0.001) and BMI (p < 0.001) were negatively associated with all muscle mass and strength variables. Men had more muscle mass and strength than women. As BMI increased, muscle mass and muscle strength decreased. Accelerometer-measured sitting and walking times were negatively associated with concentric hamstrings (p = 0.044) and quadriceps torques (p = 0.031), respectively.

Conclusion

Sex, BMI, and accelerometer-measured sitting and walking times were associated with muscle mass and/or muscle strength in healthy young adults. Women and those with a high BMI need interventions to improve their muscle mass and strength. The paradox regarding the association of PA with muscle mass and strength in younger adults may be due to possible influences from other factors (e.g., resistance training, dietary intakes, etc.) superseding that of accelerometer-measured PA.

Associations of sedentary behavior and screen time with biomarkers of inflammation and insulin resistance

Sedentary behavior (SB) has been linked to risk factors of cardiometabolic disease, with inconsistent findings reported in the literature. We aimed to assess the associations of SB with multiple biomarkers of inflammation and insulin resistance in adults. Domain-specific SB, sitting time and moderate-to-vigorous physical activity (MVPA) were measured in 78 adults (mean ± SD 52.0 ± 10.8 y). Body fat percentage (BF%) was assessed using multi-frequency bioelectrical impedance. A blood draw assessed glucose, insulin, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), leptin, and adiponectin. Adiponectin-leptin ratio (ALR), homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β) were calculated. Multivariable linear regression analyses, controlling for age, sex, MVPA, and BF%, were used to assess associations. After adjustment for age, sex and MVPA, total SB (7.5 ± 2.5 h/day) was positively associated with leptin, insulin, HOMA-IR, HOMA-β (Standardized Beta (β) range 0.21-0.32) and negatively associated with ALR (β = -0.24, p < 0.05 for all). Similarly, total sitting time (7.2 ± 2.9 h/day) was associated with TNF-α (β = 0.22) and ALR (β = -0.26). These associations were attenuated to non-significance after adjustment for BF%. Leisure screen time was detrimentally associated with IL-6 (β = 0.24), leptin (β = 0.21), insulin (β = 0.37), HOMA-IR (β = 0.37), and HOMA-β (β = 0.34), independent of age, sex and MVPA (p < 0.05 for all). Only the associations with insulin (β = 0.26), HOMA-IR (β = 0.26), and HOMA-β (β = 0.23) remained significant after further controlling BF% (p < 0.05). Self-reported SB is associated with biomarkers of inflammation and insulin resistance, independent of MVPA, and in some cases BF%.

Mapping sedentary behaviour (MAPS-B) in winter and spring using wearable sensors, indoor positioning systems, and diaries in older adults who are pre-frail and frail: A feasibility longitudinal study

Older adults who are frail are likely to be sedentary. Prior interventions to reduce sedentary time in older adults have not been effective as there is little research about the context of sedentary behaviour (posture, location, purpose, social environment). Moreover, there is limited evidence on feasible measures to assess context of sedentary behaviour in older adults. The aim of our study was to determine the feasibility of measuring context of sedentary behaviour in older adults with pre-frailty or frailty using a combination of objective and self-report measures. We defined "feasibility process" using recruitment (20 participants within two-months), retention (85%), and refusal (20%) rates and "feasibility resource" if the measures capture context and can be linked (e.g., sitting-kitchen-eating-alone) and are all participants willing to use the measures. Context was assessed using a wearable sensor to assess posture, a smart home monitoring system for location, and an electronic or hard-copy diary for purpose and social context over three days in winter and spring. We approached 80 potential individuals, and 58 expressed interest; of the 58 individuals, 37 did not enroll due to lack of interest or medical mistrust (64% refusal). We recruited 21 older adults (72±7.3 years, 13 females, 13 frail) within two months and experienced two dropouts due to medical mistrust or worsening health (90% retention). The wearable sensor, indoor positioning system, and electronic diary accurately captured one domain of context, but the hard copy was often not completed with enough detail, so it was challenging to link it to the other devices. Although not all participants were willing to use the wearable sensor, indoor positioning system, or electronic diary, we were able to triage the measures of those who did. The use of wearable sensors and electronic diaries may be a feasible method to assess context of sedentary behaviour, but more research is needed with device-based measures in diverse groups.

Physical Activity Levels and Sedentary Behavior of People Living With Mild Cognitive Impairment: A Cross-Sectional Study Using Thigh-Worn Accelerometers

Community-dwelling people with Mild Cognitive Impairment self-reporting not to be meeting recommended physical activity levels participated in this study to (a) determine compliance of wearing (thigh-worn) accelerometers, (b) describe physical activity levels and sedentary behavior, and (c) determine the validity of the Physical Activity Scale for the Elderly (PASE) compared with activPAL accelerometers. A total of 79 people had valid accelerometer data (median [interquartile range]: age, 71 [54-75] years). Compliance was 86.81%. Participants were sedentary for 10.6 hr per day and engaged in a median of 9 min per day of moderate-intensity physical activity. Fair correlations were found between the PASE and total stepping time per day (r = .35, p < .01), total number of steps per day (r = .36, p < .01), and number of steps in stepping activities completed for ≤1 min (r = .42, p < .01). The PASE and Standing time (r = .04, p = .724) and PASE and Sitting time (r = .04, p = .699) had little to no relationship. The use of thigh-worn accelerometers for this population is achievable. People with Mild Cognitive Impairment have high levels of sedentary behavior and minimal engagement in moderate-intensity physical activity. The PASE has fair, positive criterion validity with activity-based outcomes measured by activPAL accelerometers but not with sedentary behavior, which is high for this population.

Cross-sectional interactive associations of physical activity and sedentary behaviour with physical capacity across adulthood

BACKGROUND

The way physical activity (PA) and sedentary behaviour (SB) independently and interactively modify the age-related decline in physical capacity remains poorly understood. This cross-sectional study investigated the independent and interactive associations of PA and SB with physical function and performance throughout the adult life course.

METHODS

Data from 499 community-dwelling adults (63% female) aged 20-92 years, involved in the INSPIRE Human Translational Cohort, were used in this cross-sectional study. Daily time spent on moderate-to-vigorous PA (MVPA, min/day) and SB (h/day) was measured with activPAL triaxial accelerometers. Physical function and performance were assessed through the measurement of the 4-m usual gait speed (m/s), handgrip strength (kg), lower-limb strength (isokinetic knee extension torque, N·m), estimated lower-limb power (five-time chair-rise test performance, s) and cardiorespiratory fitness (V̇O2max, mL/kg/min). Confounder-adjusted multiple linear and curvilinear regressions were performed to investigate how MVPA, SB and their interactions were associated with the physical outcomes (all square root-transformed except gait speed) throughout the adulthood spectrum.

RESULTS

Interaction analyses revealed that the combination of higher levels of MVPA with lower levels of SB favourably reshaped the negative relationship between handgrip strength and age (age2 × SB × MVPA: B = -7E-08, SE = 3E-08, P < 0.05). In addition, higher levels of MVPA were independently associated with an improved age-related profile in gait speed (age2 × MVPA: B = 3E-06, SE = 1E-06, P < 0.05), chair-rise performance (age × MVPA: B = -9E-05, SE = 4E-05, P < 0.05) and V̇O2max (MVPA at 21 years: B = 3E-02, SE = 7E-03, P < 0.05; age × MVPA: B = -5E-04, SE = 2E-04, P < 0.05). Conversely, the detrimental association of age with lower-limb muscle strength (age × SB: B = -1E-04, SE = 6E-05, P < 0.05) and chair-rise performance (age × SB: B = 1E-05, SE = 7E-06, P < 0.05) was exacerbated with increasing duration of SB, independently of MVPA. Supplementary analyses further revealed that some of these associations were age and sex specific.

CONCLUSIONS

This cross-sectional study demonstrated that reduced sedentary time and increased activity duration were independently and synergistically associated with an attenuated age-related loss in physical capacity. These findings need to be confirmed with longitudinal data but encourage both adopting an active lifestyle and reducing sedentary time as preventive measures against physical aging.

Association Between Typologies of Sedentary Behavior and Muscle Strength, Gait Speed, and Balance in Community-Dwelling Older Adults

Knowledge of how the different types of sedentary behaviors (SB) are associated with functional limitations can guide professionals who work with older adults on better recommendations about the amount of daily time that should be encouraged in each type of SB. The objective was to estimate the associations between two SB typologies (SB television [TV] and SB computer/internet) and the presence of handgrip strength, lower limb strength, gait speed, and balance limitations in Brazilian community-dwelling older adults. This is a cross-sectional study with 1,298 community-dwelling older adults (≥60 years). SB was assessed by self-reporting daily time spent watching TV or using computer/internet (categorized into <2, 3-4, and ≥5 hr/day). Outcomes were handgrip strength, lower limb strength, gait speed, and balance limitations considering referenced cutoff points. Older adults in SB TV ≥5 hr/day had 1.75 (95% confidence interval [CI] [1.07, 2.86]) and 1.88 (95% CI [1.02, 3.46]) times more chances of handgrip strength and gait speed limitations, respectively. On the other hand, those who spent 3-4 and ≥5 hr/day in SB computer/internet had 0.45 (95% CI [0.20, 0.99]) and 0.37 (95% CI [0.15, 0.93]) had less chances of lower limb strength and balance limitations, respectively. In conclusion, functional limitations would be associated differently depending on the type of SB in the older adults sampled.

Sedentary behaviour (especially accumulation pattern) has an independent negative impact on skeletal muscle size and architecture in community-dwelling older adults

Prolonged sedentary behaviour (SB) i.e. longer bouts, is suggested to have a range of negative health effects, independent of habitual light and medium-to-vigorous physical activity (LIPA or MVPA). Any effect on musculoskeletal size, architecture or morphology has seldom been reported in older adults. Moreover, no study has yet determined if any association would persist following adjustment for covariates. Therefore, the aim of the present study was to investigate the associations between SB, and properties of the Gastrocnemius Medialis (GM) muscle, in a cross-sectional sample of older adults using compositional data analysis. 105 healthy older adults (73±6y) wore a thigh mounted tri-axial accelerometer for seven consecutive days, and underwent ultrasound [e.g. muscle length (Lm), anatomical cross-sectional area (ACSA), muscle volume (VM), fascicle length (LF), & physiological cross-sectional area (PCSA)], body composition (e.g. DEXA) and health (e.g. medical history) assessments. In-unadjusted models, SB time was negatively associated with ACSA at 75% of Lm (R2adj = 0.085), VM (R2adj = 0.020), and PCSA (R2adj = 0.039). Standing was positively associated with pennation angle (R2adj = 0.110), which persisted following co-variate adjustment (R2adj = 0.296). In fully adjusted models, both SB & LIPA time were associated with ACSA at 75% of Lm (Both R2adj = 0.393). Standing and light activity time were also associated with LF, VM, & PCSA (R2adj 0.116-0.573). In fully adjusted models, SB pattern parameters (i.e. the manner in which sedentary behaviour is accumulated daily throughout waking hours such as the timing, duration and frequency of sedentary bouts), were associated with GM muscle properties (R2adj 0.156-0.564) including LM, LF, and VM. The pattern, rather than accumulated daily SB time, was associated with the size and architecture of the GM. Our results suggest that regardless of co-existing habitual physical activities, SB bouts should be kept short and frequently interrupted to offset some of the deleterious ageing-related muscle architecture characteristics changes.

Association of physical behaviours with sarcopenia in older adults: a systematic review and meta-analysis of observational studies

BACKGROUND

Physical behaviours (ie, physical activity and sedentary behaviour) might have a role in the development of sarcopenia, although the evidence is unclear. We aimed to explore the association of total and intensity-specific levels of physical activity and sedentary behaviour with sarcopenia and its components (ie, muscle mass, muscle strength, and physical performance) in older adults.

METHODS

We conducted a systematic review and meta-analysis and searched MEDLINE (via PubMed), Scopus, and Web of Science from inception to July 26, 2022, for peer-reviewed, observational studies or baseline data from randomised clinical trials conducted in older adults (ie, individual age ≥60 years or mean age ≥65 years) and published in English that reported on the association of physical activity or sedentary behaviour or both with sarcopenia (or its determinants: muscle mass or strength, and physical performance). Physical activity and sedentary behaviour were measured by any method. The main outcome was sarcopenia, which could be diagnosed by any means. Estimates were extracted and pooled using Bayesian meta-analytic models and publication bias was assessed using the Egger's test. This study is registered with PROSPERO, CRD42022315865.

FINDINGS

We identified 15 766 records, of which 124 studies (230 174 older adults; 121 301 [52·7%] were female and 108 873 [47·3%] were male) were included in the systematic review. 86 studies were subsequently included in the meta-analysis. Higher levels of total physical activity were inversely associated with sarcopenia both cross-sectionally (21 studies, n=59 572; odds ratio 0·49, 95% credible interval 0·37-0·62) and longitudinally (four studies, n=7545; 0·51, 0·27-0·94). A protective association was also identified for moderate-to-vigorous physical activity in cross-sectional research (five studies, n=6787; 0·85, 0·71-0·99), whereas no association was identified for the remaining physical behaviours (ie, steps, light physical activity, or sedentary behaviour).

INTERPRETATION

Total and moderate-to-vigorous physical activity are inversely associated with sarcopenia. These findings might support the importance of moderate-to-vigorous, rather than light, intensity physical activity-based interventions to prevent sarcopenia.

FUNDING

None.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Prospective associations between changes in physical activity and sedentary time and subsequent lean muscle mass in older English adults: the EPIC-Norfolk cohort study

BACKGROUND

The longitudinal associations between physical behaviours and lean muscle mass indices need to be better understood to aid healthy ageing intervention development.

METHODS

We assessed physical behaviours (total physical activity, moderate-to-vigorous physical activity (MVPA), light physical activity, total sedentary time and prolonged sedentary bout time) for 7 days using hip-worn accelerometers. We also assessed domain-specific physical behaviours (walking, cycling, gardening and housework time) with self-report questionnaires at baseline (2006-2011) and follow-up (2012-2016) in the European Prospective Investigation into Cancer (EPIC)-Norfolk study. We assessed body composition using dual-energy X-ray absorptiometry (DEXA) at follow-up in 1535 participants (≥ 60 years at baseline). From this, we derived appendicular lean muscle mass (ALM) indices (% relative ALM = (ALM/total body weight)*100), body mass index (BMI)-scaled ALM (ALM/BMI, kg/kg/m2) and height-scaled ALM (ALM/height2, kg/m2)). We evaluated the prospective associations of both baseline and change in physical behaviours with follow-up muscle mass indices using multivariable linear regression.

RESULTS

Over 5.5 years (SD 14.8) follow-up, higher baseline accelerometer-measured physical activity and lower sedentary time were associated with higher subsequent relative ALM and BMI-scaled ALM, but not height-scaled ALM (e.g. 0.02% higher subsequent relative ALM per minute/day of baseline MVPA for men). Greater increases in physical activity and greater declines in sedentary time variables were associated with higher subsequent relative ALM and BMI-scaled ALM, but not height-scaled ALM (e.g. 0.001 kg/kg/m2 subsequent BMI-scaled ALM and 0.04% subsequent relative ALM per min/day/year increases in LPA over follow-up; 0.001 kg/kg/m2 subsequent BMI-scaled ALM and -0.03% subsequent relative ALM per min/day/year less of total sedentary time over follow-up). Greater increases in women's cycling and gardening over follow-up were associated with greater subsequent relative ALM (cycling 0.9% per hour/week/year; gardening 0.2% per hour/week/year) and BMI-scaled ALM (cycling 0.03 kg/kg/m2 per hour/week/year; gardening 0.004 kg/kg/m2 per hour/week/year).

CONCLUSION

Physical behaviours across all intensities, and in women more specifically cycling and gardening, may help prevent age-related declines in muscle mass.

Guidelines to conduct research in computer-prompt software studies to decrease sedentary behaviors and increase physical activity in the workplace

BACKGROUND

Computers are ubiquitous in the workplace and facilitate prolonged sitting, which has adverse health consequences. Various computer-prompt software programs are designed to decrease sedentary behaviors and increase physical activity in the workplace. However, specific guidelines that would improve research in this area have not been published.

OBJECTIVE

The objective of this article is to present recommendations for improving computer-prompt software research, to decrease sedentary behaviors and increase physical activity in the workplace.

METHODS

Ten domains were identified based on deficiencies in the current literature combined with quality assessment tools to reduce the risk for bias. The ten domains include composition of the research team, behavioral sciences theoretical frameworks, research design, alert types, outcome measures, confounding factors, intervention duration, carryover effects, racial/ethnic composition, and organizational culture.

RESULTS

Specific recommendations are presented for each domain. The research team should include all stakeholders contributing as copartners in designing the intervention. For theory, a systems science framework was presented. Clustered randomized controlled trials were recommended, rather than randomization at the individual level. Distinct types of alerts (visual, auditory, or both) and frequency of alerts (hourly, randomly generated, or based on prolonged sitting patterns) are described. Outcome measures include average duration of sitting bouts, longest sitting bout, and number of sitting bouts.

CONCLUSION

Prolonged sitting and physical inactivity at work lead to major health problems. Adherence to the recommendations presented here should facilitate high-quality research and improve the health of desk-based workers by decreasing sedentary behaviors and increasing physical activity.

Effects of aerobic and combined aerobic-resistance exercise on motor function in sedentary older adults: A randomized clinical trial

BACKGROUND

Sedentary behavior is widespread among older adults and accelerates the decline of motor function. Nevertheless, there is insufficient evidence concerning the effectiveness of regular exercise in enhancing the same in sedentary older adults.

OBJECTIVE

To compare the effects of 24 weeks of aerobic and combined aerobic-resistance exercise on the motor function of sedentary older adults.

METHODS

Sixty healthy sedentary older (65-80 years) were randomly enrolled. Participants were randomly divided into 3 groups (1:1:1): aerobic exercise group (AEG), combined aerobic-resistance exercise group (CEG), and health education group (HEG). The training group underwent a five-day-a-week regimen, with each session lasting for 40 minutes (including 10 min warm-up and cool-down). HEG received only monthly health lectures. We assessed lower limb muscle strength (30-second sit-to-stand ability), single-dual task gait, static and dynamic balance functions at baseline and after 24 weeks of intervention using per-protocol analysis.

RESULTS

Among 60 elderly healthy who were randomized (mean age 70.59 ± 3.31 years; 28 women (46%)), 42 (70%) completed the evaluation after 24 weeks. Both the aerobic exercise and combined aerobic-resistance exercise groups exhibited improved 30-second sit-to-stand ability, static balance in closed-eye standing mode, and dynamic balance (P< 0.05). However, there were no statistically significant changes in the single-task gait parameters of stride length, stride width, and stride speed (P> 0.05). Additionally, compared to the aerobic exercise group, the combined exercise group showed an increase in dual-task gait speed and medial and lateral dynamic stability indices (P< 0.05).

CONCLUSION

Both the aerobic exercise and combined aerobic-resistance exercise programs are effective in enhancing lower limb muscle strength, dynamic balance, and static balance while standing with eyes closed in sedentary older adults. Furthermore, the combined aerobic-resistance exercise program is more effective in improving dual-task gait speed as well as medial and lateral dynamic balance.

Habitual physical activity and sedentary behavior as predictors of dynapenia in older adults: a cross-sectional study

BACKGROUND

Dynapenia is a risk factor of mortality. Therefore, the development of low-cost and easy-to-apply tools is essential to optimize the health surveillance actions of older people.

OBJECTIVES

To compare the time spent on habitual physical activity (HPA) and sedentary behavior (SB) among dynapenic and non-dynapenic older adults and ascertain the predictive ability of these behaviors on outcome.

DESIGN AND SETTING

A cross-sectional population epidemiological survey was conducted involving 208 older adults.

METHODS

HPA and SB were quantified using the International Physical Activity Questionnaire, and dynapenia was identified by handgrip strength (women: 18.37 kgf; men: 26.75 kgf).

RESULTS

The prevalence was 24.50%. In both sexes, dynapenic individuals reported a HPA median time of 70.00 minutes/week (min/wk), while non-dynapenic women and men reported HPA median times of 240.00 and 280.00 min/wk, respectively (P < 0.05). For SB among dynapenic individuals, a median of 388.75 min/day was observed in women and 428.57 min/d in men. In contrast, non-dynapenic women and men had 291.42 and 274.28 min/day in SB (P < 0.05), respectively. The best cutoff HPA to discriminate the outcome was 150.00 min/wk in women (sensitivity: 73.30%; specificity: 60.67%) and 140.00 min/wk in men (sensitivity, 71.43%; specificity, 61.54%). The best cutoff SB was 381.43 min/day in women (sensitivity, 53.30%; specificity, 84.80%) and 351.43 min/day in men (sensitivity, 71.43%; specificity, 73.85%).

CONCLUSION

Older individuals with dynapenia spent less time on HPA and more time in SB. Furthermore, HPA was found to be a better discriminator of dynapenic individuals, and SB better discriminated non-dynapenic individuals.

Dose-response effects of periodic physical activity breaks on the chronic inflammatory risk associated with sedentary behavior in high- and upper-middle income countries: A systematic review and meta-analysis

BACKGROUND AND AIMS

Though moderate-vigorous physical activity (MVPA) is speculated to mitigate the inflammatory risk associated with sedentary behavior, only a fraction of the global population meets the recommended weekly dose of MVPA. More individuals indulge in bouted and sporadic light-intensity physical activity (LIPA) that occurs throughout the typical day. However, the anti-inflammatory effects of LIPA or MVPA breaks during prolonged sitting remains unclear.

METHODS

A systematic search was done on six peer-reviewed databases through January 27th, 2023. Two authors independently screened the citations for eligibility, and risk of bias and performed a meta-analysis.

RESULTS

The included studies originated from high and upper - middle income countries. Observational studies of SB interruptions with LIPA showed favourable effects on inflammatory mediators such as higher levels of adiponectin (odds ratio, OR = +0.14; p = 0.02). However, these findings are not supported by the experimental studies. Experimental studies reported non-significant increase in cytokines including IL-1β (standardised mean difference, SMD = 0.11 pg/ml; p = 0.29) and IL-6 (SMD = 0.19 pg/ml; p = 0.46) after interrupting sitting with LIPA breaks. But these LIPA breaks were found to reduce C-reactive protein (SMD = - 0.50 mg/dl; p = 0.85) and IL-8 levels (SMD = -0.08 pg/ml; p = 0.34) but did not reach statistical significance.

CONCLUSION

Interrupting prolonged sitting time with LIPA breaks shows promise for preventing the inflammatory effects associated with prolonged bouts of daily sitting, though the evidence remains in infancy and limited to high- and upper-middle income countries.

Short bouts of walking attenuates the response of IL-8 to prolonged sitting in healthy adults

PURPOSE

Experimental studies have shown that prolonged sitting for 2-8 h can cause changes to vascular and metabolic markers; the response of pro-inflammatory cytokines is relatively unexplored. The purpose of this study is to determine the response of interleukin-8 (IL-8) to prolonged and interrupted sitting.

METHODS

Healthy participants (n = 24, 21.1 years ± 2.2, 50% female) completed a prolonged sitting session (4 h) and an interrupted sitting session (4 h of sitting with 3 min of walking at 60%HRmax, every 30 min) in random order. Saliva and capillary plasma were collected at the beginning (T1) and at the end of each session (T2).

RESULTS

Salivary concentrations of IL-8 increased during the prolonged (T1 median: 22.09 pg/mL, T2 median: 86.18 pg/mL; p =  < 0.01, ES - 0.55) and interrupted (T1 median: 22.09 pg/mL, T2 median: 51.99 pg/mL; p = 0.021, ES - 0.34) sessions; however, the increase during interrupted sitting was lower (PS median: 134.4%, range: - 43.96 to 1115.69 and IS median: 50.8%, range: - 75.5 to 356.35; p = 0.011, ES - 0.53). In the sub-sample of males, salivary IL-8 did not increase in the interrupted session (T1 median: 22.09, range: 3.496-699.12, and T2 median: 24.96, range: 5.11-533.5, p =  > 0.05, ES - 0.16). No significant findings were observed for IL-8 in the plasma.

CONCLUSION

Prolonged sitting appears to increase concentrations of the pro-inflammatory cytokine IL-8 while interrupting this sitting with short bouts of walking blunts this response. Sex appears to moderate this relationship; however, there appears to be a large amount of individual variability.

The Frail-LESS (LEss Sitting and Sarcopenia in Frail older adults) intervention to improve sarcopenia and maintain independent living via reductions in prolonged sitting: a randomised controlled feasibility trial protocol

BACKGROUND

Sarcopenia is a progressive and generalised loss of muscle mass and function with advancing age and is a major contributor to frailty. These conditions lead to functional disability, loss of independence, and lower quality of life. Sedentary behaviour is adversely associated with sarcopenia and frailty. Reducing and breaking up sitting should thus be explored as an intervention target for their management. The primary aim of this study, therefore, is to examine the feasibility, safety, and acceptability of conducting a randomised controlled trial (RCT) that evaluates a remotely delivered intervention to improve sarcopenia and independent living via reducing and breaking up sitting in frail older adults.

METHODS

This mixed-methods randomised controlled feasibility trial will recruit 60 community-dwelling older adults aged ≥ 65 years with very mild or mild frailty. After baseline measures, participants will be randomised to receive the Frail-LESS (LEss Sitting and Sarcopenia in Frail older adults) intervention or serve as controls (usual care) for 6 months. Frail-LESS is a remotely delivered intervention comprising of tailored feedback on sitting, information on the health risks of excess sitting, supported goal setting and action planning, a wearable device that tracks inactive time and provides alerts to move, health coaching, and peer support. Feasibility will be assessed in terms of recruitment, retention and data completion rates. A process evaluation will assess intervention acceptability, safety, and fidelity of the trial. The following measures will be taken at baseline, 3 months, and 6 months: sitting, standing, and stepping using a thigh-worn activPAL4 device, sarcopenia (via hand grip strength, muscle mass, and physical function), mood, wellbeing, and quality of life.

DISCUSSION

This study will determine the feasibility, safety, and acceptability of evaluating a remote intervention to reduce and break up sitting to support improvements in sarcopenia and independent living in frail older adults. A future definitive RCT to determine intervention effectiveness will be informed by the study findings.

TRIAL REGISTRATION

ISRCTN, ISRCTN17158017; Registered 6 August 2021, https://www.isrctn.com/ISRCTN17158017.

Dynapenia in all-cause mortality and its relationship with sedentary behavior in community-dwelling older adults

The aim of the present study was to investigate the relationship of dynapenia combined with sedentary behavior (SB) on the risk of mortality in older adults living in a Brazilian community. A total of 322 participants aged ≥ 60 years from the ELSIA (Longitudinal Study of Elderly Health in Alcobaça) prospective cohort were included. Dynapenia was diagnosed when the handgrip strength was < 27 ​kg for men and < 16 ​kg for women. The exposure time to SB was assessed considering the total time spent sitting during one day in the week and one day on the weekend. When combined with dynapenia, we derived the construction of four groups: best behavior (absence of dynapenia and low SB), intermediate behavior (absence of dynapenia and high SB; presence of dynapenia and low SB) and worst behavior (presence of dynapenia and high SB). Mortality was assessed by the follow-up time until death and/or censorship. During the 5-year follow-up of the study, 55 participants progressed to death. In the adjusted models, the dynapenia and the time spent exposed to SB were analyzed in a combined way, the older adults with worse behavior (high SB and dynapenia) had higher risk ratios for mortality (hazard ratio 2.46; 95% confidence interval 1.01-5.97) than the best behavior group. Older adults with dynapenia are at greater risk for all-cause mortality, which is aggravated by the addition of longer exposure to SB.

Bidirectional associations of accelerometer-assessed physical activity and sedentary time with physical function among older English adults: the EPIC-Norfolk cohort study

To develop healthy ageing interventions, longitudinal associations between objectively assessed physical behaviours and physical function need to be better understood. We assessed associations between accelerometer-assessed total physical activity (PA), moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), sedentary time and prolonged sedentary bout time, and clinically assessed physical function (grip strength, usual walking speed (UWS), chair stand speed) at two time-points in 3188 participants (≥ 60 years) of the EPIC-Norfolk study. Bidirectional associations were assessed using multivariable linear regression. Over an average of 6.1 years, baseline physical behaviours (greater total PA, MVPA and LPA, and less sedentary time) were associated with better subsequent walking and chair stand speed. Better baseline physical function was associated with better follow-up physical behaviours. There were no bidirectional associations between changes in physical behaviours and grip strength. Improvements in UWS were associated with improvements in all physical behaviours. Improvements in chair stand speed were associated with improvements in total PA, MVPA, and sedentary bout time. Improvements in physical behaviours were associated with improvements in UWS (3.1 cm/s/yr per 100 cpm/yr  total PA, 3.6 cm/s/yr per hr/day/yr MVPA, 2.5 cm/s/yr per hr/day/yr LPA, - 2.9 cm/s/yr per hour/day/yr sedentary time, and - 1.6 cm/s/yr per hr/day/yr prolonged sedentary bout time). Only improvements in total PA, MVPA and sedentary bout time were associated with improvements in chair stand speed. In conclusion, we found bidirectional associations between changes in some physical behaviours and physical function and between baseline physical behaviours and subsequent physical function, highlighting the importance of considering the full range of physical behaviours to promote healthy ageing.

Sarcopenia in community-dwelling older adults is associated with the diversity and composition of the gut microbiota

Sarcopenia is a prognostic indicator of negative consequences in older adults, including physical disability, frailty, and mortality. Few studies have investigated the associations between sarcopenia and the gut microbiota. We sought such associations in community-dwelling older adults aged ≥60 years. Sarcopenia was defined as low muscle mass, plus reduced physical performance, and/or low skeletal muscle strength. 16S rRNA next-generation sequencing was used to identify the components of the gut microbiota in fecal samples from 27 older adults with sarcopenia and 33 without sarcopenia. Relationships between sarcopenia and the diversity and composition of the gut microbiota were analyzed. Diversities at the species level were detected between the sarcopenia and control groups (P = 0.049). The abundance of Prevotella and Prevotella copri was significantly lower (P = 0.021 and P = 0.018 respectively) and that of Parabacteroides sp. higher in the sarcopenia than the control group (P = 0.010). Linear discriminant analysis of effect size revealed differences in the microbiota composition between the two groups. Sarcopenia was related with the presence of Anaerotruncus and Phascolarctobacterium sp. and the absence of Prevotella sp. and Prevotella copri. Further research is warranted to clarify whether changes in the gut microbiota cause sarcopenia onset or development.

Linear and non-linear associations of device-measured sedentary time with older adults' skeletal muscle mass

BACKGROUND

Time spent sitting is associated adversely with health outcomes in older adults. Nevertheless, it is not clear how sedentary time may be related to appendicular skeletal muscle mass (ASM) - a key attribute of sarcopenia. This cross-sectional study examined associations of total sedentary time with ASM among community-dwelling older Japanese males and females.

METHODS

Participants (n = 281, 74.3 ± 5.2 yr) wore a tri-axial accelerometer for seven days. Body mass index-adjusted ASM (kg/BMI) was derived from bioimpedance measures. Multivariate linear and quadratic regression models examined the associations of ASM with total sedentary time, stratified by sex. Restricted cubic spline models were fitted to estimate non-linear associations. Isotemporal substitution (IS) models were used to estimate the impacts of replacing 30-minute of sedentary time with light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA).

RESULTS

After adjustment, total sedentary time had a significant linear and negative association with ASM among females (β = -0.014; p = 0.023). For males, total sedentary time had a significant quadratic association (p = 0.020). Spline models indicated a reverse U-shaped association (p < 0.001) with total sedentary time over 9.3 h/day being associated with lower ASM. The IS models indicated that replacing 30 min/day of sedentary time with LPA would be positively and significantly associated with older females' ASM (β = 0.007, p = 0.022).

CONCLUSIONS

In older Japanese adults, higher volumes of time spent sedentary were associated with lower ASM. For males, only very high volumes of sedentary time appeared to be detrimental. These adverse relationships may in part be offset by more time spent in either LPA or MVPA.

Replacing Sedentary Behavior With Physical Activity of Different Intensities: Implications for Physical Function, Muscle Function, and Disability in Octogenarians Living in Long-Term Care Facilities

BACKGROUND

We investigated the associations of replacing sedentary behavior (SB) with physical activity of different intensities on the physical function of octogenarians living in long-term care facilities.

METHODS

This pooled study recruited 427 older adults aged 80 years and older (69.1% female; body mass index: 27.53). For 345 participants who provided valid data, we assessed device-measured time spent in SB, light-intensity physical activity (LIPA), and moderate to vigorous physical activity (MVPA). We assessed lower limb physical function, strength, mobility, and disability. We used compositional data analysis to investigate the associations of replacing SB with physical activity on the outcomes.

RESULTS

Reallocation of SB to LIPA and MVPA was associated with a higher number of 30-second Chair Stand cycles (LIPA: +0.21, MVPA: +1.81; P < .001), greater peak force (LIPA: +11.96 N, MVPA: +27.68 N; P < .001), peak power (LIPA: +35.82 W, MVPA: +92.73 W; P < .001), peak velocity (LIPA: +0.03 m/s, MVPA: +0.12 m/s; P < .001), higher levels of grip strength (LIPA: +0.68 kg, MVPA: +2.49 kg; P < .001), and less time in the Time Up and Go (LIPA: -7.63 s, MVPA: -12.43 s; P < .001).

CONCLUSIONS

Replacing SB with LIPA or MVPA is associated with physical function and disability of older adults living in long-term care facilities.

Use of activPAL to Measure Physical Activity in Community Dwelling Older Adults, A Systematic Review

Objective

To perform a systematic review of the literature to describe how the activPAL accelerometer has been used to measure physical activity (PA) in community-dwelling older adults to standardize collection of PA data in this population using this thigh-worn accelerometer.

Data Sources

A comprehensive search of the following databases was completed: Cumulative Index to Nursing and Allied Health Complete, Embase, OVID Medicine, PubMed/Web of Science, and Scopus.

Study Selection

Studies were included if published before August 1, 2020, were written in English, and used activPAL to measure PA in community-dwelling, noninstitutionalized adults 65 years or older. Titles and abstracts were independently reviewed, and the decision to include or exclude was made by 100% consensus.

Data Extraction

Three research team members independently extracted the data from included studies. Extracted data were compared and discussed with relevant information included. Study quality was assessed using the Quality Assessment Tool for Observational Cohort and Cross-sectional Studies.

Data Synthesis

A total of 7 articles met the inclusion criteria. Three of the 7 studies used activPAL to report steps/d, ranging from 864-15847 steps/d. Time spent stepping or walking was reported by 4 studies using various units. Sit-to-stand transitions were reported by 4 studies, averaging 10-63 transitions/d. Sedentary time was assessed in 6 studies, whereas moderate to vigorous physical activity was not measured using activPAL in any study.

Conclusions

The activPAL is most often used to collect data on step count and walking, sit-to-stand transitions, and sedentary time in community-dwelling older adults.

Sedentary lifestyle and body composition in type 2 diabetes

BACKGROUND

Body composition alterations may participate in the pathophysiological processes of type 2 diabetes (T2D). A sedentary lifestyle may be responsible for alterations of body composition and adverse consequences, but on which body composition of patients with T2D and to what extent the sedentary lifestyle has an effect have been poorly investigated.

METHODS

We recruited 402 patients with T2D for this cross-sectional study. All patients received questionnaires to evaluate sedentary time and were further divided into three subgroups: low sedentary time (LST, < 4 h, n = 109), middle sedentary time (MST, 4-8 h, n = 129) and high sedentary time (HST, > 8 h, n = 164). Each patient underwent a dual energy X-ray absorptiometry (DXA) scan to detect body composition, which included body fat percentage (B-FAT), trunk fat percentage (T-FAT), appendicular skeletal muscle index (ASMI), lumbar spine bone mineral density (BMD) (LS-BMD), femoral neck BMD (FN-BMD), hip BMD (H-BMD) and total BMD (T-BMD). Other relevant clinical data were also collected.

RESULTS

With increasing sedentary time (from the LST to HST group), B-FAT and T-FAT were notably increased, while ASMI, LS-BMD, FN-BMD, H-BMD and T-BMD were decreased (p for trend < 0.01). After adjustment for other relevant clinical factors and with the LST group as the reference, the adjusted mean changes [B (95% CI)] in B-FAT, T-FAT, ASMI, LS-BMD, FN-BMD, H-BMD and T-BMD in the HST group were 2.011(1.014 to 3.008)%, 1.951(0.705 to 3.197)%, - 0.377(- 0.531 to - 0.223) kg/m2, - 0.083(- 0.124 to - 0.042) g/cm2, - 0.051(- 0.079 to - 0.024) g/cm2, - 0.059(- 0.087 to - 0.031) g/cm2 and - 0.060(- 0.088 to - 0.033) g/cm2, p < 0.01, respectively.

CONCLUSIONS

A sedentary lifestyle may independently account for increases in trunk and body fat percentage and decreases in appendicular skeletal muscle mass and BMD of the lumbar spine, femoral neck, hip and total body in patients with T2D.

Effectiveness of a Water Intake Program at the Workplace in Physical and Mental Health Outcomes

Introduction

Adequate water intake is a low-cost and effectively non-invasive strategy for individual health outcomes. We aimed to demonstrate the efficacy of water intake intervention in intensive-labor and static-type workplaces.

Method

Smart drinking cups were provided to the participants, and a built-in application (App) associated with the cup was downloaded on their phones. The App collected and recorded the amount of drinking water consumed by the participants set reminders for drinking water and drinking water health education information. We assessed the data, including the amount of and time interval between water intake, sedentary time, the degree of physical and psychological importance of oneself, self-satisfaction, and physical fitness.

Results

After the intervention, water intake in the two companies significantly increased during the reminder period compared with the non-reminder period. A significant increase was noted in week 3 in the amount of water intake by the participants after using the App, and the total sedentary time considerably decreased. Furthermore, the interval between water consumption decreased compared with the preintervention interval. The systolic and diastolic blood pressure decreased in the participants working at the static-type and intensive-labor workplaces after the intervention, respectively. The participants ' lower limb muscle performance also improved significantly, and the emphasis on self-care was significantly improved.

Conclusions

The health-promoting effects of the water intake wellness intervention were akin to the butterfly effect. Besides significantly increasing water intake, the intervention improved other health behaviors, thereby benefiting physical and mental health. Hence, promoting water consumption in workplaces till it becomes a habit may benefit the employees.

Reallocation of time spent on sedentary behavior by time spent on physical activity reduces dynapenia in older adults: a prospective cohort study

BACKGROUND

Dynapenia is characterized by mobility limitations in the older population when combined with aggravating behavioral factors that can increase the risk of morbidity and mortality.

OBJECTIVE

To investigate the hypothetical effects of reallocation of time spent on sedentary behavior (SB), moderate-to-vigorous physical activity (MVPA), and sleep on dynapenia in older adults.

DESIGN AND SETTING

A prospective cohort study using exploratory surveys in Alcobaça City, Bahia State, Brazil.

METHODS

In total, 176 older adults (≥ 60 years) of both sexes participated in this study. Dynapenia was assessed using the handgrip strength test with cutoff points of < 27 kg for men and < 16 kg for women. MVPA and SB were assessed using the International Physical Activity Questionnaire, and sleep was assessed using the Pittsburgh Sleep Quality Index.

RESULTS

Effects on reallocation were found for the shortest times, such as 10 minutes (odds ratio (OR) 0.92; 95% confidence interval (CI): 0.85-0.99); substituting MVPA with SB increased the chances of dynapenia by 58.0% (95% CI: 1.01-2.49). Analyzing the substitution of 60 minutes/day of SB with 60 minutes/day of MVPA revealed a protective effect, with a lower OR for dynapenia of 37.0% (OR 0.63; 95% CI: 0.40-0.99). The reallocation of sleep time did not significantly reduce dynapenia.

CONCLUSIONS

Substituting the time spent sitting with the same amount of time spent on MVPA can reduce dynapenia, and a longer reallocation time confers greater health benefits in older adults.

Development and Validation of a Nomogram for Predicting Sarcopenia in Community-Dwelling Older Adults

OBJECTIVE

To establish and validate a nomogram that predicts the risk of sarcopenia for community-dwelling older residents.

DESIGN

Retrospective study.

SETTING AND PARTICIPANTS

A total of 1050 community-dwelling older adults.

METHODS

Data from a survey of community-dwelling older residents (≥60 years old) in Hunan, China, from June to September 2019 were retrospectively analyzed. The survey included general demographic information, diet, and exercise habits. Sarcopenia diagnosis was according to 2019 Asian Working Group for Sarcopenia criteria. Participants were randomly divided into the development group and validation groups. Independent risk factors were screened by multivariate logistic regression analysis. Based on the independent risk factors, a nomogram model was developed to predict the risk of sarcopenia for community-dwelling older adults. Both in the development and validation sets, the discrimination, calibration, and clinical practicability of the nomogram were verified using receiver operating characteristic curve analysis, Hosmer-Lemeshow test, and decision curve analysis, respectively.

RESULTS

Sarcopenia was identified in 263 (25.0%) participants. Age, body mass index, marital status, regular physical activity habit, uninterrupted sedentary time, and dietary diversity score were significant contributors to sarcopenia risk. A nomogram for predicting sarcopenia in community-dwelling older adults was developed using these factors. Receiver operating characteristic curve analysis showed that the area under the curve was 0.827 (95% CI 0.792-0.860) and 0.755 (95% CI 0.680-0.837) in the development and validation sets, respectively. The Hosmer-Lemeshow test yielded P values of .609 and .565, respectively, for the 2 sets. The nomogram demonstrated a high net benefit in the clinical decision curve in both sets.

CONCLUSIONS AND IMPLICATIONS

This study developed and validated a risk prediction nomogram for sarcopenia among community-dwelling older adults. Sarcopenia risk was classified as low (<11%), moderate (11%-70%), and high (>70%). This nomogram provides an accurate visual tool to medical staff, caregivers, and older adults for prediction, early intervention, and graded management of sarcopenia.

Associations of accelerometer-determined physical activity and sedentary behavior with sarcopenia and incident falls over 12 months in community-dwelling Swedish older adults

PURPOSE

This study was aimed to determine associations of accelerometer-determined time and bouts of sedentary behavior, light physical activity (LPA), and moderate-to-vigorous PA (MVPA) with sarcopenia and incident falls over 12 months.

METHODS

A total of 3334 Swedish 70-year-olds were assessed for sarcopenia, as defined by the revised definition of the European Working Group on Sarcopenia in Older People. Assessments were based on low scores for appendicular lean mass (dual-energy X-ray absorptiometry), hand grip strength, and the Timed Up and Go test. For 7 days after baseline, total time and total number of bouts (≥10 min of continuous activity at a given intensity) of activity performed at sedentary, LPA, and MVPA intensities were assessed by accelerometer. Incident falls were self-reported 6 months and 12 months after baseline.

RESULTS

Only 1.8% of participants had probable or confirmed sarcopenia. After multivariable adjustment for other levels of activity, only greater MVPA time was associated with a decreased likelihood of having low appendicular lean mass, low hand grip strength, and slow Timed Up and Go time as defined by the European Working Group on Sarcopenia in Older People criteria (all p < 0.05), and only MVPA time was associated with lower likelihood of probable or confirmed sarcopenia (odds ratio = 0.80, 95% confidence interval: 0.71-0.91 h/week). Similar associations were identified for total number of bouts, with no evidence of threshold effects for longer duration of bouts of MVPA. A total of 14% of participants reported ≥1 fall, but neither total time nor bouts of activity was associated with incident falls (all p > 0.05).

CONCLUSION

Higher amounts of accelerometer-determined MVPA are consistently associated with a decreased likelihood of sarcopenia and its components, regardless of the length of bouts or amounts of sedentary behavior.

Computer Prompt Software to Reduce Sedentary Behavior and Promote Physical Activity Among Desk-Based Workers: A Systematic Review

OBJECTIVE

Do computer prompt software programs at the workplace reduce sitting time and/or increase physical activity at work?

BACKGROUND

Many products are promoted and being used in the workplace; however, their effectiveness and use are unknown or the evidence base that they work to change behavior is lacking.

METHOD

We searched for relevant papers published between 2005 and 2020. The inclusion criteria were computer prompt software programs installed as behavioral change interventions; interventions implemented during work hours and delivered through a work personal computer or laptop; and measures of sedentary behavior and/or physical activity. To minimize risk of bias, three recommended best-evidence synthesis criteria were used: random assignment, sample size, and external validity. Based on these criteria, articles were selected and evaluated.

RESULTS

Six publications met the quality threshold for review. Seven articles did not meet the quality threshold. Four of the six included publications found that computer prompt software programs decreased sedentary behavior and/or increased physical activity. Two publications reported inconsistent results.

CONCLUSIONS

The promising results from this systematic review indicate that there is potential for computer prompt software programs to improve the health of desk-based workers. For conclusive findings, more high-quality, scientific studies are needed.

APPLICATION

The best-evidence publications in this review can serve as a guide in selecting and implementing computer prompt software programs at the workplace to decrease sedentary behavior and increase physical activity.

Descriptive Epidemiology of Interruptions to Free-Living Sitting Time in Middle-Age and Older Adults

National guidelines recommend physically active interruptions to sitting time, however, the characteristics of these interruptions are broadly stated and ill-defined. A robust methodology for population surveillance for such interruptions is needed.

PURPOSE

To describe the frequency and characteristics (i.e., duration, stepping time, and estimated intensity) of all interruptions and physically active interruptions to adults' free-living sitting time (i.e., transitions from sitting to upright posture) across segments of the population.

METHODS

Australian Diabetes, Obesity and Lifestyle (AusDiab) study participants (321 men; 406 women; mean ± SD 58.0 ± 10.3 years) wore the activPAL3TM for ≥1 valid day. The characteristics of interruptions from laboratory studies demonstrating health benefits were selected to define active interruptions (≥5 min upright and/or ≥ 2 min stepping) and ambulatory interruptions (≥2 min stepping). The frequency and characteristics of all, active, and ambulatory interruptions were described and compared by age, gender, diabetes status, and body mass index.

RESULTS

Adults averaged 55.0 ± 21.8 interruptions per day, but only 20.3 ± 6.7 were active and 14.0 ± 5.4 were ambulatory. Median (25th, 75th percentile) duration was 2.6 (0.9, 7.8) minutes, stepping time was 0.8 (0.3, 2.0) minutes, and estimated energy expenditure was 4.3 (1.4, 12.5) MET-min. Those who were older, had obesity, or had diabetes had significantly (p < 0.05) fewer interruptions of all types and less stepping time during active interruptions than their counterparts (Cohen's d < 0.2).

CONCLUSION

Free-living interruptions were often less active than interruptions performed in effective acute laboratory studies and their content varied widely between population groups. Monitoring all interruptions as well as those that are more active is advisable to provide a comprehensive understanding of free-living sedentary behavior.

Understanding Variations in the Health Consequences of Sedentary Behavior: A Taxonomy of Social Interaction, Novelty, Choice, and Cognition

The study of sedentary behaviors requires taxonomies (classification schemes) to standardize data collection, measurements, and outcomes. Three taxonomies of sedentary behaviors have been identified, but none address an important challenge in sedentary behavior research, which is to distinguish between beneficial and detrimental health effects of various sedentary behaviors. Some sedentary behaviors (e.g., reading) are associated with positive health outcomes, whereas other sedentary behaviors (e.g., television viewing) are associated with adverse health outcomes. To address directly this complexity and present a different conception and understanding of discrepant findings related to health outcomes, a new taxonomy is needed. The development of the new taxonomy is guided by analysis of literature and selection of a relevant and informative behavioral sciences theoretical framework (i.e., self-determination theory). Because older adults are an increasing percentage of the population and report a high prevalence of sedentary behaviors, the new taxonomy was designed for older adults with potential application to all age groups. Taylor's taxonomy of sedentary behaviors is parsimonious with four domains: social interaction (i.e., not solitary, companionship, interacting, and connecting with others); novelty (i.e., refreshingly new, unusual, or different); choice (i.e., volition, preferred option or alternative, the power, freedom, or decision to choose); and cognition (i.e., mentally stimulating and engaging).

Associations between strength, flexibility, and painful symptomology in university staff

BACKGROUND

In the adult population, the work environment and physical fitness levels are directly related to the onset of musculoskeletal pain, repetitive strain injuries, and decreased blood circulation. Although low levels of muscle strength and flexibility may lead to a higher prevalence of pain, specific anatomic regions are poorly addressed.

OBJECTIVE

To investigate the prevalence of musculoskeletal pain and the association between strength or flexibility and pain in university staff.

METHODS

The sample was composed of 110 members of staff from a university in Guarapuava-PR. Body mass and height values were obtained, from which the BMI was calculated. The pain evaluation was performed by means of a questionnaire, analyzing the intensity, frequency, and anatomical region. The subjects were then submitted to strength (right and left hand grip, lumbar traction, lower limb traction) and flexibility tests (sit and reach test).

RESULTS

The anatomical region with the highest prevalence of pain was the lumbar region (43.4%). When the association between the presence of pain and flexibility was performed, only the lumbar traction presented significant results, with the weakest group demonstrating pain (OR: 3.47 [1.27 - 9.49]).

CONCLUSION

The results demonstrate that low levels of strength in the lumbar region are associated with the presence of painful symptomatology.

Association between dietary protein intake and skeletal muscle mass in older Korean adults

PURPOSE

We investigated the association of low and high daily protein intakes on skeletal muscle mass status in Korean adults aged 60 years and older.

METHODS

This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey conducted between 2008 and 2011. The participants' dietary protein intake was assessed using the 24-h dietary recall method and was classified as low (< 0.8 g/kg body weight/day), moderate (0.8-1.2 g/kg/day), and high (> 1.2 g/kg/day). Amount of skeletal muscle mass was measured using whole-body dual-energy X-ray absorptiometry. Low skeletal muscle mass was defined as appendicular skeletal muscle mass index < 7.0 kg/m² in men and < 5.4 kg/m² in women.

RESULTS

The study included data from 4585 participants (2022 men and 2563 women). All skeletal muscle parameters in women and total lean mass in men decreased as the amount of protein consumed daily increased. However, there was no association between high or low protein intake and low skeletal muscle mass in men or women.

CONCLUSIONS

No association was found between the amount of daily protein intake and skeletal muscle mass status in older Korean adults. Gender-specific further studies focussing on the interactions of dietary protein intake under specific conditions including physical activity status and the daily distribution of protein intake and the quality and source of the protein are needed to evaluate the impact of protein intake status on muscle health in older Koreans.

Decreased continuous sitting time increases heart rate variability in patients with cardiovascular risk factors

Aim

The purpose of the present study was to elucidate the relationship between high-frequency heart rate variability (HF HRV) and continuous daytime sitting time in patients with cardiovascular risk factors such as mild hypertension and/or stable angina pectoris.

Background

Decreased HF HRV precedes the progression and worsening of cardiovascular diseases. Continuous sitting behavior is a major risk factor for developing metabolic syndrome and is associated with cardiovascular disease, diabetes mellitus, renal failure, sarcopenia and osteoporosis. Risk factors for cardiovascular disease can be affected by continuous daytime sitting behaviors.

Design

The present study design was a post-hoc comparison.

Methods

Patients treated at two different primary care clinics from 2014 to 2018 were enrolled in this study (n = 53). We assessed HF HRV and continuous sitting time using 24-hour Holter electrocardiography and an activity meter at baseline and 6 months. HF HRV was calculated during sleep.

Results

Sitting time had decreased in 22 patients (decreased group) and increased in 31 patients (increased group) after 6 months. The mean patient ages were 73.1 and 72.0 years in the decreased and increased sitting time groups, respectively (p = 0.503). HF HRV during sleep had increased after 6 months in the decreased sitting time group. Compared with the increased group, the decreased group showed significantly higher HF HRV during sleep after 6 months by two-way repeated-measures ANOVA after adjustment for age, sex and change in activity (p = 0.045).

Conclusion

These results suggest that a decrease in sitting time might induce parasympathetic activity during sleep. Therefore, reducing continuous sitting time during the day might contribute, in part, to improving the prognosis of patients with cardiovascular risk factors not only by avoiding muscle loss but also by providing positive influences on parasympathetic tone during sleep.

The association of objectively measured physical activity and sedentary behavior with skeletal muscle strength and muscle power in older adults: A systematic review and meta-analysis

BACKGROUND

Engaging in physical activity (PA) and avoiding sedentary behavior (SB) are important for healthy ageing with benefits including the mitigation of disability and mortality. Whether benefits extend to key determinants of disability and mortality, namely muscle strength and muscle power, is unclear.

AIMS

This systematic review aimed to describe the association of objective measures of PA and SB with measures of skeletal muscle strength and muscle power in community-dwelling older adults.

METHODS

Six databases were searched from their inception to June 21^st, 2020 for articles reporting associations between objectively measured PA and SB and upper body or lower body muscle strength or muscle power in community dwelling adults aged 60 years and older. An overview of associations was visualized by effect direction heat maps, standardized effect sizes were estimated with albatross plots and summarized in box plots. Articles reporting adjusted standardized regression coefficients (β) were included in meta-analyses.

RESULTS

A total of 112 articles were included representing 43,796 individuals (range: 21 to 3726 per article) with a mean or median age from 61.0 to 88.0 years (mean 56.4 % female). Higher PA measures and lower SB were associated with better upper body muscle strength (hand grip strength), upper body muscle power (arm curl), lower body muscle strength, and lower body muscle power (chair stand test). Median standardized effect sizes were consistently larger for measures of PA and SB with lower compared to upper body muscle strength and muscle power. The meta-analyses of adjusted β coefficients confirmed the associations between total PA (TPA), moderate-to-vigorous PA (MVPA) and light PA (LPA) with hand grip strength (β = 0.041, β = 0.057, and β = 0.070, respectively, all p ≤ 0.001), and TPA and MVPA with chair stand test (β = 0.199 and β = 0.211, respectively, all p ≤ 0.001).

CONCLUSIONS

Higher PA and lower SB are associated with greater skeletal muscle strength and muscle power, particularly with the chair stand test.

A Rapidly Aging World in the 21st Century: Hopes from Glycomics and Unraveling the Biomarkers of Aging with the Sugar Code

A global rise in life expectancy comes with an increased burden of serious life-long health issues and the need for useful real-time measures of the aging processes. Studies have shown the value of biochemical signatures of immunoglobulin G (IgG) N-glycosylation as clinically relevant biomarkers to differentiate healthy from accelerated aging. Most human biological processes rely on glycosylation of proteins to regulate their function, but these events appear sensitive to environmental changes, age, and the presence of disease. Specifically, variations in N-glycosylation of IgG can adversely affect inflammatory pathways underpinning unhealthy aging and chronic disease pathogenesis. This expert review highlights the discrepancies between an organism's age in years of life (chronological age) versus age in terms of health status (biological age). The article examines and synthesizes the studies on IgG N-glycan profiles and the third alphabet of life, the sugar code, in relation to their relevance as dynamic indicators of aging, and to differentiate between normal and accelerated aging. The levels of N-glycan structures change with aging, suggesting that monitoring the alterations of serum glycan biosignatures with glycomics might allow real-time studies of human aging in the near future. Glycomics brings in yet another systems science technology platform to strengthen the emerging multiomics studies of aging and aging-related diseases.

Impact of dietary protein intake on the incidence of low muscle strength in middle-aged and older adults

BACKGROUND

A reduction in skeletal muscle strength is a prognostic indicator of negative consequences, such as physical disability, frailty, and mortality in older adults. Studies investigating associations between the risk of reduction in skeletal muscle strength and the amount of dietary protein which is a factor influenced muscle health are scarce, particularly in Asian populations. Therefore, we investigated the association between the amount and change in daily protein intake and the prospective risk of developing low skeletal muscle strength in middle-aged and older adults.

METHODS

This study used data from the Korean Genome and Epidemiology Study as an ongoing population-based cohort study of adults aged 40 years and over. The amount of daily protein consumed was assessed using a semi-quantitative food frequency questionnaire. Low skeletal muscle strength was measured with a handgrip strength dynamometer.

RESULTS

In total, 32,458 adults (11,358 males and 21,100 females) were evaluated. The amount of daily dietary protein consumed was not associated with the risk of low muscle strength over the 4-year follow-up period after adjusting for covariates. No associations between low muscle strength events according to the change in the amount of protein consumed from the baseline to the follow-up surveys were identified.

CONCLUSIONS

The amount of and change in dietary protein consumed were not associated with developing low muscle strength in middle-aged and older adults. Further studies with a focus on physical activity-protein intake interactions and specific conditions, such as mobility-limited adults or hospitalized patients, are warranted to clarify the relationship between protein intake status and the incidence of low skeletal muscle strength.

Physical activity, sedentary behavior and functionality in older adults: A cross-sectional path analysis

Disability is negatively associated with the health of older adults, and it can be mediated by healthy lifestyles and behaviors throughout one's life. In this context, understanding the interrelationships between sedentary behavior, physical activity and functionality may assist in the implementation of effective public health actions. Thus, the aim of the present study was to investigate the relationships between both physical activity and sedentary behavior and functionality in older adults and the possible mediators. The variables analyzed were selected according to the content analysis of International Classification of Functioning, Disability and Health model, and included activity, participation, health conditions, body functions and structures, environmental factors and personal factors. 419 individuals participated in the study. Physical activity was directly associated with disability in instrumental activities of daily living (IADL), and the association was mediated by self-esteem, aerobic endurance, and agility/balance. Sedentary behavior was indirectly associated with IADL disability, and the association was mediated by aerobic resistance, nutritional status, and agility/balance. Regarding the basic activities of daily living (BADL), physical activity showed an indirect association mediated by aerobic resistance and IADL. The association of sedentary behavior with BADL was mediated by aerobic resistance and lower limb flexibility. These results reinforce the idea that functionality is multidimensional, and the mediating factors must be considered when strategies for promoting physical activity and reducing sedentary behavior are designed.

The Effects of Displacing Sedentary Behavior With Two Distinct Patterns of Light Activity on Health Outcomes in Older Adults (Implications for COVID-19 Quarantine)

Rationale: The COVID-19 pandemic is limiting outdoor and community-based activities, especially for older adults owing to the requirement for self-isolation, potentially increasing prolonged sedentary behavior (SB). Given a poor tolerance for intense exercise, SB displacement with light intensity physical activity (LIPA) is a promising health enhancing alternative. Therefore, the aims of this study were to investigate the effects of two different types of SB displacement on health outcomes in older adults and any differential impact of associated LIPA pattern.

Method: 28 older women (age: 73 ± 5 years, height: 1.60 ± 0.07 m, weight: 67 ± 10 kg, and BMI: 26.1 ± 3.6 kg/m²) underwent overnight fasted dual energy x-ray absorptiometry (DEXA) imaging, blood sampling, and functional assessments before being randomly allocated to one of two groups: (1) single continuous bout of 45–50 min LIPA daily (n = 14); or (2) SB fragmentation (SBF; ~48 min LIPA daily, 2 min LIPA for every 30 min of SB; n = 14). Compliance was systematically monitored using tri-axial accelerometery. All measures were taken at weeks 0 and 8.

Results: Physical behavior significantly altered (decreased SB/increased LIPA; p < 0.05) and to a similar extent in both groups. We observed a significant reduction in serum triglycerides [p = 0.045, effect size (ɳ_p²) = 0.15; SBF: −0.26 ± 0.77 mmol/L, LIPA: −0.26 ± 0.51 mmol/L], improved 30 s sit-to-stand (STS) count (p = 0.002, ɳ_p² = 0.32, 2 ± 3 STS) and speed (p = 0.009, ɳ_p² = 0.35, −10 ± 33%), as well as increased average handgrip strength (p = 0.001, ɳ_p² = 0.45, 6 ± 12%), and gait speed (p = 0.005, ɳ_p² = 0.27, 0.09 ± 0.16 m/s) in both groups. Interestingly, SBF caused a greater increase in peak handgrip strength (8 ± 14%), compared to LIPA (2 ± 10%; p = 0.04, ɳ_p² = 0.38).

Conclusion: SB displacement induced significant improvements in fasting triglycerides, gait speed, as-well as STS endurance/speed in older women. Frequent vs. continuous SB displacement also caused greater increases in handgrip strength. While both SB displacement protocols display promise as efficacious home-based interventions for self-isolating older adults, our results would suggest a physical functioning advantage of the SBF protocol for certain outcomes.

Predictive factors of functional mobility in older women after 12 weeks of resistance training

To analyze the association between functional mobility and anthropometric and functional characteristics of older women after 12 weeks of resistance training. METHODS: Forty-seven community-dwelling older women underwent 12 weeks of supervised resistance training twice a week. The dependent variable (mobility measured by the Timed Up and Go test) and the independent variables (age, body mass index, fat-free mass of the lower limbs, waist circumference, peak knee torque at 60º/s, peak knee torque at 180º/s, functional reach test, and 30-second chair stand test) were measured before and after the intervention. RESULTS: A multivariate analysis showed that age, body mass index, waist circumference, and the 30-second stand test predicted 30% (R2 = 0.30; p = 0.001; F = 5.53) of the total variance regarding an improvement in mobility after resistance training (p < 0.0001; [95% CI 0.72–1.20]; the effect size was considered large [0.90]) when comparing women before and after the intervention. CONCLUSIONS: Age, body mass index, waist circumference, and the 30-second stand test predicted 30% of the increase in functional mobility.

Minimizing sedentary behavior (without increasing medium-to-vigorous exercise) associated functional improvement in older women is somewhat dependent on a measurable increase in muscle size

The optimal pattern of sedentarism displacement and mechanisms underlying its health effects are poorly understood. Therefore, the aim of this study was to quantify muscle-tendon adaptation in response to two different sedentarism displacement interventions and relate any adaptations to functional outcomes. Thirty-four older women (73±5yrs) underwent skeletal muscle-tendon size and functional assessments. Participants were randomly allocated to: Sedentary behavior fragmentation (SBF), Light intensity physical activity (LIPA), or Control groups. Measures were taken at weeks 0 and 8. Gait speed significantly increased (p=0.003), in both experimental groups (SBF: 0.06 ± 0.08m/s, 6±10%, LIPA: 0.06 ± 0.07m/s, 6±6%), but not control (-0.02 ± 0.12m/s, -2±9%). Accordingly, the relative change in Vastus Lateralis muscle volume, accounted for 30% (p=0.027), and 45% (p=0.0006) of the explained variance in the relative change in gait speed, for SBF and LIPA respectively. Gastrocnemius Medialis fascicle length changes were positively associated with gait speed changes, following LIPA exclusively (R²= 0.50, p=0.009). This is the first study to show SBF and LIPA are adequate loading in older women, with related muscle adaptation and clinically relevant gait speed improvements. Such adaptations appear similar irrespective of whether sedentarism displacement is prescribed in a single bout (LIPA) or in frequent micro-bouts (SBF).

Associations of sitting and physical activity with grip strength and balance in mid-life: 1970 British Cohort Study

Strength and balance training are now recommended in many physical activity (PA) guidelines. However, it is unclear whether these recommendations are applicable to middle-aged adults. We aimed to examine the associations of sitting and physical activity times with grip strength and standing balance performance in mid-life. Up to 4726 participants from the 1970 British Cohort study, with data on sitting and activity (measured using a thigh-worn accelerometer (activPAL3-micro)), grip strength and balance times at age 46 years were included in analyses. Associations of sitting, moderate-vigorous, and total PA times with grip strength and balance performance were tested using linear and multinomial logistic regression models, respectively. Greater time spent sitting was associated with weaker grip strength even after adjustment for potential confounders and MVPA time (fully adjusted regression coefficient: -0.51 kg (95% CI: -0.63, -0.39) per 1-hour sitting/day). Associations of PA time with grip strength were not independent of sitting time. There was only a weak association between sitting time and balance performance but greater MVPA and total PA times were associated with higher relative risks of successfully balancing for 30 seconds with eyes closed (vs poor balance). However, these associations were fully attenuated after adjustments for covariates. In summary, among a sample of middle-aged adults a robust association between sitting time and grip strength was observed. These findings suggest potential benefits of actively promoting less sitting alongside activities that specifically benefit muscle strength and balance performance in mid-life to ensure that people maintain all important aspects of their physical capability as they age.

Is replacing sedentary time with bouts of physical activity associated with inflammatory biomarkers in children?

This study aimed to investigate the theoretical impact of reallocating a specific amount of sedentary time with an equal amount of (a) total and (b) ≥1-minute bout-accumulated time spent in different activity intensities, on inflammatory biomarkers in 8- to 9-year-old children. Accelerometry and inflammatory biomarker baseline data from the Transform-Us! Study (complete cases n = 149) were utilized. Isotemporal linear models with the Gaussian distribution and identity link functions were used to assess associations between the activity replacements and seven individual inflammatory biomarkers, including C-reactive protein (CRP), and Interleukin (IL)-2, IL-6, IL-8, and IL-10, as well as combined inflammatory and pro-inflammatory composite scores. Eighty-five percent of children met physical activity recommendations. Replacing 10 minutes of sedentary time per day with VPA, regardless of how this was accumulated, was beneficially associated with CRP and both combined composite scores. In contrast, replacing 10 min/day of sedentary time with ≥ 1-minute MPA bouts was detrimentally associated with CRP and the inflammatory composite score. Substitutions with other activity intensities were not significantly associated with any individual inflammatory biomarkers, or combined inflammatory and pro-inflammatory composite scores. In healthy and active school-aged children, evidence of the theoretical impact of replacing sedentary time with physical activity, regardless of intensity or accumulation, on markers of systemic inflammation was limited. Longitudinal research is needed to investigate the long-term impacts of reallocating sedentary time with physical activity, and particularly VPA, for inflammatory biomarkers in children, including those with increased risk of inflammation.

Displacing Sedentary Behaviour with Light Intensity Physical Activity Spontaneously Alters Habitual Macronutrient Intake and Enhances Dietary Quality in Older Females

Displacing Sedentary Behaviour (SB) with light intensity physical activity (LIPA) is increasingly viewed as a viable means of health enhancement. It is, however, unclear whether any behavioural compensations accompany such an intervention. Therefore, the aim of this study was to identify any dietary changes that accompany SB displacement. We hypothesised that SB displacement would improve dietary quality. Thirty-five elderly females (73 ± 5 years) were randomly allocated to one of three groups: (1) sedentary behaviour fragmentation (SBF) (n = 14), (2) continuous LIPA (n = 14), or (3) control (n = 7). Habitual diet (four-day food diary) and physical behaviour (accelerometery) were assessed at weeks 0 and 8. Out of 45 nutrients examined, only glucose exhibited a group × time interaction (p = 0.03), mediated by an exclusive reduction following SBF (-31%). SBF was also the sole experimental group to increase nutrients promoting bone health (SBF: 17%, LIPA: -34%. control: 21%), whereas both experimental groups consumed more nutrients promoting anabolism (SBF: 13%, LIPA: 4%, control: -34%) (z-scores). New ambulators (n = 8) also consumed more nutrients promoting bone health (16%)/anabolism (2%) (z-scores), including significantly increased Zinc intake (p = 0.05, 29%). Displacing SB with LIPA improves dietary quality in older females. Furthermore, SB fragmentation appears advantageous for various dietary outcomes.

A Cross-Sectional Examination of Patterns of Sedentary Behavior and Cardiometabolic Risk in Community-Dwelling Adults Aged 55 Years and Older

Introduction

Sedentary behavior (SB) is highly prevalent among older adults, with more than 25% engaging in 6 hours or more of SB daily. SB has been associated with several cardiometabolic biomarkers in younger adults; however, there is a paucity of research in older populations. This study examined associations between patterns of SB and cardiometabolic biomarkers in community-dwelling adults aged 55 years and older.

Methods

Data were drawn from a convenience sample of 54 community-dwelling individuals (12 males, 42 females; mean age = 72.6 ± 6.8 years, range = 56–89 years). Cardiometabolic biomarkers assessed included systolic (SBP) and diastolic blood pressure (DBP), body mass index, waist circumference, and fasting blood glucose and cholesterol parameters. SB was assessed via accelerometry over a 7-day period, and measures included daily time in SB, number and length of sedentary bouts, the number and length of breaks between sedentary bouts, moderate-to-vigorous physical activity (MVPA), and light physical activity (LPA). Associations between the SB measures and each cardiometabolic risk factor were examined using separate stepwise multiple regression models, controlling for sex, MVPA, and accelerometer wear time. Isotemporal substitution models were used to examine the change in cardiometabolic outcomes when SB is replaced by an equal duration of either LPA or MVPA.

Results

Adjusted regression analyses showed that daily sedentary time was positively associated with DBP (β = 0.052, ∆R² = 0.112, p = 0.022) and inversely associated with HDL cholesterol (β = −0.111, ∆R² = 0.121, p = 0.039). Sedentary bout length was also associated with DBP and HDL cholesterol (β = 0.575, ∆R² = 0.152, p = 0.007; β = −1.529, ∆R² = 0.196, p = 0.007, respectively). Replacement of 10 minutes of SB a day with LPA was associated with improved DBP and HDL cholesterol (p ≤ 0.05). No other significant associations (p ≤ 0.05) were found.

Conclusion

Sitting for prolonged periods of time without interruption is unfavorably associated with DBP and HDL cholesterol. Prospective studies should identify causal relationships and observe specific changes in cardiometabolic profiles in older populations.

Device-measured sedentary behavior and physical activity in older adults differ by demographic and health-related factors

Background

Our aim was to describe and explore older adults' device-measured sedentary behavior and physical activity (PA) pattern by sex, age, education, marital status, body mass index, and physical function; and to assess agreement regarding fulfillment of PA recommendations, i.e. 150 min/week of moderate-to-vigorous intensity PA (MVPA), between device-measured and self-reported PA.

Method

We included 656 older adults (64% women), aged 66, 81-87 or ≥ 90 years from a Swedish population-based cohort study. The activPAL3 accelerometer provided information on sedentary behavior (sedentary time, sedentary bouts, sit-to-stand transitions) and PA. Stepping ≥100 steps/min was considered MVPA; standing and stepping < 100 steps/min were considered light-intensity PA (LPA). Self-reported PA was compared with min/week in MVPA and steps/day.

Results

On average, 60% of wear time was spent sedentary, 36% in LPA, and 4% in MVPA. Relative to men, women, had significantly (p < 0.05) more sit-to-stand transitions, spent 33 min/day less sedentary and 27 min/day more in LPA, and were more likely to report meeting PA recommendations, but showed no difference in steps/day, MVPA, or sedentary bout duration. Older age was associated with more sedentary time, lower MVPA and fewer steps/day. The prevalence of meeting PA recommendations was 59% device-measured and 88% by self-report with limited agreement between methods (Cohen's Kappa = 0.21, Spearman's rho = 0.28). Age differences were much more pronounced with objective measures than by self-report.

Conclusions

We found significant sex differences in sedentary behavior and time in LPA in older adults, but not in MVPA, in contrast to previous findings. Sedentary time increased with age, with small differences in accumulation pattern. MVPA time was lower with older age, obesity, and poor physical function. A majority of the participants > 80 years did not meet the PA recommendations. Given the strong relationships between sedentary behavior, PA and health in older adults, programs are needed to address these behaviors. Agreement between device-measured and self-reported fulfillment of PA recommendations was limited. Device-based measurement adds value to PA studies, providing richer and different data than self-report.

Sedentary Behavior, Exercise, and Cardiovascular Health

Sedentary behavior and physical inactivity are among the leading modifiable risk factors worldwide for cardiovascular disease and all-cause mortality. The promotion of physical activity and exercise training (ET) leading to improved levels of cardiorespiratory fitness is needed in all age groups, race, and ethnicities and both sexes to prevent many chronic diseases, especially cardiovascular disease. In this state-of-the-art review, we discuss the negative impact of sedentary behavior and physical inactivity, as well as the beneficial effects of physical activity /ET and cardiorespiratory fitness for the prevention of chronic noncommunicable diseases, including cardiovascular disease. We review the prognostic utility of cardiorespiratory fitness compared with obesity and the metabolic syndrome, as well as the increase of physical activity /ET for patients with heart failure as a therapeutic strategy, and ET dosing. Greater efforts at preventing sedentary behavior and physical inactivity while promoting physical activity, ET, and cardiorespiratory fitness are needed throughout the healthcare system worldwide and particularly in the United States in which the burden of cardiometabolic diseases remains extremely high.

Diclofenac attenuates inflammation through TLR4 pathway and improves exercise performance after exhaustive swimming

BACKGROUND

The use of NSAIDs has become a common practice to counteract the pro-inflammatory acute effects of exercise, in order to improve sports performance. The liver, due to its central role in energy metabolism, may be involved primarily in the process of ROS generation and consequently inflammation after exhaustive exercise.

OBJECTIVE

To analyze the influence of diclofenac on the liver TLR4 pathway and time to exhaustion in rats submitted to repeated exhaustive swimming.

METHODS

An exhaustive test was performed in order to mimic athletes' routine, and inflammatory status and oxidative stress markers were evaluated in the liver. Animals were divided into sedentary and exhaustion groups, with this last performing three exhaustive swimming bouts. At the same time, diclofenac or saline was pre-administered once a day for nine days.

RESULTS

Data showed significantly increased COX-2, TLR4, and MyD88 protein content in the liver after exhaustive swimming bouts. The levels of pro-inflammatory cytokines also increased after exhaustive exercise, while these effects were attenuated in the group treated with diclofenac plus exhaustive swimming bouts. The anti-inflammatory modulation provoked by diclofenac treatment was associated with an increased time to exhaustion in the exercise bouts. The exhaustive exercise increased TBARS formation, but diclofenac treatment blunted this elevation, while GSH/GSSG ratios in both exhaustion-saline and exhaustion-diclofenac-treated groups were lower than in the sedentary-saline group.

CONCLUSIONS

Our findings suggest that diclofenac may improve exercise performance and represent an effective tool to ameliorate the pro-inflammatory status in liver when associated with exhaustive exercise, and the liver may be a possible therapeutic target.

Sitting time and associated factors among Portuguese older adults: results from Nutrition UP 65

Older adults are particularly susceptible to sedentary behaviours. Sitting time has been increasingly referred to as a potentially modifiable risk factor in the prevention of chronic diseases. Identifying factors associated with sitting time, particularly those that are modifiable, will allow for more effective public health strategies. This study aimed to describe sitting time among Portuguese older adults and to evaluate associated factors. A cross-sectional study including 1423 older adults ≥ 65 years old was conducted. Sitting time was assessed with the International Physical Activity Questionnaire. Socio-demographic, health, anthropometric and functional variables were collected. Bivariate and multivariate linear regression models were conducted to study the association between these variables and sitting time. The median of sitting time was 300 min/day (interquartile range = 240 min/day), which is equal to 5 h/day. The following factors were directly associated with longer sitting time: being male, age ≥ 80 years, living in Central or Southern Portugal, being retired from work, as well as presenting low physical activity, obesity or longer time to walk 4.6 metres. On the other hand, being married, having higher education and higher household income were inversely associated with longer sitting time. It can be concluded that Portuguese older adults spend a considerable amount of time sitting per day. Potentially modifiable risk factors associated with longer sitting time in this population were related to nutritional status and functional ability.