Prolonged Leisure Time Spent Sitting in Relation to Cause-Specific Mortality in a Large US Cohort

Causal relationships of physical activity and leisure sedentary behaviors with COPD: A Mendelian randomization study

BACKGROUND

Chronic diseases such as chronic obstructive pulmonary disease (COPD) have been linked to low levels of physical activity (PA) and higher frequency of leisure sedentary behavior (LSB). The main causes of COPD include respiratory and peripheral muscle dysfunction, low levels of PA, and LSB which are associated with a higher risk of developing COPD. The attribution relationship between PA or LSB and COPD risk or COPD respiratory insufficiency is unclear. To explore this further, we conducted a Mendelian randomization (MR) study using a genotype-simulated randomized trial group to systematically evaluate the causal relationships of PA/LSB on COPD risk and respiratory insufficiency.

METHODS

The exposure data were obtained from large-scale genome-wide association studies (GWAS), including the PA dataset (N = 729,373) and LSB dataset (N = 1,109,337). The outcome data were derived from the Finn-Gen COPD dataset (N = 381,392). The causal effects were estimated with IVW1, MR-Egger, and WM2. Sensitivity analysis was conducted using Cochran's Q test, MR-Egger intercept test, MR-PRESSO3, leave-one-out analysis, and funnel plot to estimate the robustness of our findings.

RESULTS

Genetically predicted leisure television (TV) watching significantly increased the risk of COPD (OR = 2.4895, 95 % CI: 1.85259 to 3.34536; P = 1.44 × 10-9) and COPD respiratory insufficiency (OR = 2.55, 95 % CI: 1.53 to 4.27; P = 3.54 × 10-4). No casual effect of other PA or LSB phenotypes on COPD risk or respiratory insufficiency was observed.

CONCLUSION

Our study provides evidence that TV watching may increase the risk of COPD and its related respiratory insufficiency. These findings emphasized the importance of promoting regular physical exercise and reducing leisure sedentary behavior to prevent COPD.

Association between a changeable lifestyle, sedentary behavior, and suicide risk: A systematic review and meta-analysis

BACKGROUND

Suicide and self-injury have become increasingly serious public health crises. Yet current evidence about the association between sedentary behavior (SB) and suicide is inconclusive. We explore the relationship between SB and suicide behavior to provide intervention measures to change the risk factors of the latter.

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science from database inception to September 10, 2023. Adjusted odds ratios (ORs) with 95 % confidence intervals (CIs) were used as effect measures. Subgroup analysis was conducted based on gender, regions and countries, age, and study type.

RESULTS

A total of 13 studies were included. According to the meta-analysis of suicide type, compared with individuals without sedentary behavior, individuals with sedentary behavior have a higher risk of suicide attempt (OR = 1.23, 95%CI: 1.15-1.37, p < 0.001), suicide ideation (OR = 1.47, 95%CI:1.28-1.68, p < 0.001) and suicide plan (OR = 1.30, 95%CI:1.16-1.44, p < 0.001). We conducted multiple subgroup analyses for different suicidal behaviors. The analysis found that SB can increase the risk of suicide attempt in different subgroups of different genders, different research centers, Africa, and adolescents; SB can increase the risk of suicide ideation in the subgroups of different genders and ages, different research centers, Asia and Africa; SB can increase the risk of suicide plan in the subgroups of different genders, multi-center study, Africa, and adolescents.

LIMITATIONS

Future research should focus on objective SB measurement and explore its dose-response relation and time limit.

CONCLUSION

A sedentary lifestyle is associated with suicide behavior risk, with varying effects across age groups and regions, as evidenced in both single-center and multi-center studies.

Causal association of leisure sedentary behavior and cervical spondylosis, sciatica, intervertebral disk disorders, and low back pain: a Mendelian randomization study

Background

Some studies suggest sedentary behavior is a risk factor for musculoskeletal disorders. This study aimed to investigate the potential causal association between leisure sedentary behavior (LSB) (including television (TV) viewing, computer use, and driving) and the incidence of sciatica, intervertebral disk degeneration (IVDD), low back pain (LBP), and cervical spondylosis (CS).

Methods

We obtained the data of LSB, CS, IVDD, LBP, sciatica and proposed mediators from the gene-wide association studies (GWAS). The causal effects were examined by Inverse Variance Weighted (IVW) test, MR-Egger, weighted median, weighted mode and simple mode. And sensitivity analysis was performed using MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO) and MR-Egger intercept test. Multivariable MR (MVMR) was conducted to investigate the independent factor of other LSB; while two-step MR analysis was used to explore the potential mediators including Body mass index (BMI), smoking initiation, type 2 diabetes mellitus (T2DM), major depressive disorder (MDD), schizophrenia, bipolar disorder between the causal association of LSB and these diseases based on previous studies.

Results

Genetically associated TV viewing was positively associated with the risk of CS (OR = 1.61, 95%CI = 1.25 to 2.07, p = 0.002), IVDD (OR = 2.10, 95%CI = 1.77 to 2.48, p = 3.79 × 10-18), LBP (OR = 1.84, 95%CI = 1.53 to 2.21, p = 1.04 × 10-10) and sciatica (OR = 1.82, 95% CI = 1.45 to 2.27, p = 1.42 × 10-7). While computer use was associated with a reduced risk of IVDD (OR = 0.66, 95%CI = 0.55 to 0.79, p = 8.06 × 10-6), LBP (OR = 0.49, 95%CI = 0.40 to 0.59, p = 2.68 × 10-13) and sciatica (OR = 0.58, 95%CI = 0.46 to 0.75, p = 1.98 × 10-5). Sensitivity analysis validated the robustness of MR outcomes. MVMR analysis showed that the causal effect of TV viewing on IVDD (OR = 1.59, 95%CI = 1.13 to 2.25, p = 0.008), LBP (OR = 2.15, 95%CI = 1.50 to 3.08, p = 3.38 × 10-5), and sciatica (OR = 1.61, 95%CI = 1.03 to 2.52, p = 0.037) was independent of other LSB. Furthermore, two-step MR analysis indicated that BMI, smoking initiation, T2DM may mediate the causal effect of TV viewing on these diseases.

Conclusion

This study provides empirical evidence supporting a positive causal association between TV viewing and sciatica, IVDD and LBP, which were potentially mediated by BMI, smoking initiation and T2DM.

Association between frailty and sleep quality in people living with multiple sclerosis and obesity: An observational cross-sectional study

BACKGROUND

A majority of the people with multiple sclerosis (pwMS) experience sleep disturbances. Frailty is also common in pwMS. The geriatric literature strongly suggests that frailty is associated with worse sleep outcomes in community-dwelling older adults, but this association has yet to be explored among pwMS. This study focused on examining the association between frailty and sleep quality in pwMS.

METHODS

Seventy-six people with both MS and obesity (mean age: 47.6 ± 10.9 years, 81.6 % female, mean body mass index (BMI): 37.10 ± 5.5 kg/m2, mean Patient Determined Disease Steps (PDDS): 0.82 ± 1.20) were included in this cross-sectional secondary analysis. A comprehensive frailty index (FI) based on 41 health deficits from various health domains was calculated based on standardized procedures. Sleep quality was determined by the Pittsburgh Sleep Quality Index questionnaire (PSQI).

RESULTS

Overall, 67.1 % of the participants were identified as non-frail (FI ≤ 0.25), and 32.9 % were identified as frail (FI > 0.25). A significant correlation was observed between FI scores and global PSQI scores (ρ = 0.43, p < 0.05). Cross-tabulation analyses revealed that frail participants had worse subjective sleep quality, sleep latency, habitual sleep efficiency, sleep disturbances, daytime dysfunction, and higher use of sleep medications compared to non-frail participants (p < 0.05).

CONCLUSIONS

The current study identified a significant association between frailty and sleep quality in people with both MS and obesity with minimal disability. These findings underscore the importance of untangling the relationship between frailty and sleep quality in pwMS. These results could lead to a more targeted approach for rehabilitation interventions aiming to improve frailty in MS.

Sitting may increase risk for radiographic incidence and progression of knee osteoarthritis over 2 years: Data from a large cohort study

OBJECTIVES

To examine the association of leisure-time sitting with radiographic incidence and progression of knee osteoarthritis (OA) over 2 years, and to determine whether worktime sitting modifies this association.

METHODS

We included adults with or at high risk for knee OA who enroled in the Osteoarthritis Initiative (OAI). Participants reported leisure-time sitting (≤4 vs. >4 h/day) and worktime sitting (frequent vs. infrequent) at enrolment, and had bilateral knee radiographs at enrolment and 2 years later. Our outcome, radiographic knee OA incidence/progression (yes/no), was defined as any increase in Kellgren-Lawrence grade over 2 years. We examined the association of leisure-time sitting (≤4 vs. >4 h/day) with risk of radiographic knee OA incidence/progression using binary linear regression, adjusting for potential confounders. We stratified by worktime sitting (frequent vs. infrequent) and repeated our analysis.

RESULTS

We included 4254 adults (mean age 61 years; 58% women; mean body mass index 29 kg/m2 ) who contributed a total of 8127 knees. Adults with >4 h/day of leisure-time sitting had 25% higher risk (adjusted risk ratio [RR] 1.25, 95% confidence interval [95% CI] 1.08-1.50) for radiographic knee OA incidence/progression compared with adults with ≤4 h/day of leisure-time sitting (referent group). Importantly, this association was intensified (RR 1.60, 95% CI 1.19-2.33) among adults with frequent worktime sitting, but was attenuated (RR 1.11, 95% CI 0.89-1.39) among adults with infrequent worktime sitting.

CONCLUSIONS

Higher leisure-time sitting (>4 h/day) may be associated with greater risk for radiographic knee OA incidence/progression over 2 years. Furthermore, this association was intensified among adults who also reported frequent worktime sitting.

Causal links between socioeconomic status, leisure sedentary behaviours and gastro-oesophageal reflux disease: a multivariable two-sample Mendelian randomisation study

INTRODUCTION

We implemented a two-sample multivariable Mendelian randomisation (MR) analyses to estimate the causal effect of socioeconomic status and leisure sedentary behaviours on gastro-oesophageal reflux disease (GERD).

METHODS

Independent single-nucleotide polymorphisms associated with socioeconomic status and leisure sedentary behaviours at the genome-wide significance level from the Medical Research Council Integrative Epidemiology Unit (MRC-IEU) UK Biobank were selected as instrumental variables. Summary-level data for GERD were obtained from a recent publicly available genome-wide association involving 78 707 GERD cases and 288 734 controls of European descent. Univariable and multivariable two-sample MR analyses, using inverse variance weighted method for primary analyses, were performed to jointly evaluate the effect of socioeconomic status and leisure sedentary behaviours on GERD risk.

RESULTS

Three socioeconomic status, including educational attainment (OR 0.46; 95% CI 0.30 to 0.69; p<0.001), average total household income before tax (OR 0.65; 95% CI 0.47 to 0.90; p=0.009) and Townsend Deprivation Index at recruitment (OR 1.60; 95% CI 1.06 to 2.41; p=0.026), were independently and predominately responsible for the genetic causal effect on GERD. In addition, one leisure sedentary behaviour, such as time spent watching television, was independently and predominately responsible for genetic causal effect on GERD (OR 3.74; 95% CI 2.89 to 4.84; p<0.001). No causal effects of social activities and driving on GERD were observed.

CONCLUSIONS

Genetically predicted Townsend Deprivation Index at recruitment and leisure watching television were causally associated with increased risk of GERD, and age at completion of full-time education and average total household income before tax were causally associated with decreased risk of GERD.

The impact of the COVID-19 pandemic on cardiovascular health behaviors and risk factors: A new troubling normal that may be here to stay

In March 2020, the Coronavirus disease 2019 (COVID-19) outbreak was officially declared a global pandemic, leading to closure of public facilities, enforced social distancing and stay-at-home mandates to limit exposures and reduce transmission rates. While the severity of this "lockdown" period varied by country, the disruptions of the pandemic on multiple facets of life (e.g., daily activities, education, the workplace) as well as the social, economic, and healthcare systems impacts were unprecedented. These disruptions and impacts are having a profound negative effect on multiple facets of behavioral health and psychosocial wellbeing that are inextricably linked to cardiometabolic health and associated with adverse outcomes of COVID-19. For example, adoption of various cardiometabolic risk behavior behaviors observed during the pandemic contributed to irretractable trends in weight gain and poor mental health, raising concerns on the possible long-term consequences of the pandemic on cardiometabolic disease risk, and vulnerabilities to future viral pandemics. The purpose of this review is to summarize the direct and indirect effects of the pandemic on cardiometabolic health risk behaviors, particularly related to poor diet quality, physical inactivity and sedentary behaviors, smoking, sleep patterns and mental health. Additional insights into how the pandemic has amplified cardiovascular risk behaviors, particularly in our most vulnerable populations, and the potential implications for the future if these modifiable risk behaviors do not become better controlled, are described.

Sedentary behavior and the risk of stroke: A systematic review and dose-response meta-analysis

BACKGROUND AND AIMS

The sedentary behavior in people's daily life has continued to increase in recent years, causing many studies to focus on its relationship with diseases. Several studies have shown that sedentary behavior is an independent risk factor for cardiovascular disease and metabolic disease. Therefore, we performed a meta-analysis to assess the association between sedentary behavior and the risk of stroke.

METHODS AND RESULTS

Two independent investigators searched for prospective cohort studies on the association between sedentary behavior and stroke risk, published before February 2022. We pooled adjusted effect size and performed the dose-response analysis by random-effect model. Seven studies with 677,614 participants and 15,135 stroke events during a median follow-up of 12.2 years were included. The pooled hazard ratio (HR) of stroke was 1.16 (95% confidence interval [CI]: 1.09-1.24) with no significant heterogeneity (I2 = 0.0%, p for heterogeneity = 0.983). In dose-response analysis, a nonlinear association between sedentary behavior and stroke risk was discovered. Stroke risk began to increase when sedentary time exceeded 3.7 h/d (HR, 1.01; 95% CI, 0.97-1.05). And when reached 11 h/d, a significantly increased risk of stroke was observed (HR, 1.21; 95% CI 1.12-1.31).

CONCLUSION

A nonlinear association was found in the dose-response analysis, with increased risk only when sedentary time exceeded a certain level. Further research is needed to explain the biological mechanisms by which sedentary time above a certain threshold significantly increases stroke risk. (PROSPERO registration number: CRD42022311544).

Association between Sedentary Time and Falls among Middle-Aged Women in Japan

There are many reports on the risk of falls in older adults but none regarding the risk among middle-aged people. We aimed to determine fall risk factors among middle-aged women. The participants comprised 1421 women aged 40 to 64 years; anthropometric and other measurements were obtained, and lifestyle factors were examined using a self-administered questionnaire. The participants were categorized into two groups (No-fall and Fall/Almost-fall) based on their questionnaire responses. The No-fall and Fall/Almost-fall groups comprised 1114 and 307 participants, respectively. Body mass index, abdominal circumference measurements, and prevalence of dyslipidemia were significantly higher in the Fall/Almost-fall group. Additionally, those in the Fall/Almost-fall group had a shorter two-step test, experienced difficulty performing the 40 cm single-leg sit-to-stand test, and had higher 25-question Geriatric Locomotive Function Scale (GLFS-25) scores than those in the No-fall group. The results of the adjusted logistic regression analysis indicated that physical activity, higher GLFS-25 scores, and sedentary time of more than seven hours were all risk factors for falling or almost falling. Longer sedentary time is a new risk factor for falls among middle-aged women. It is necessary for people to be concerned with their sedentary behavior, such as by reducing or interrupting continuous sedentary time.

A cross-sectional comparative study on the effects of body mass index and exercise/sedentary on serum asprosin in male college students

Adipocytes regulate the body’s metabolism by secreting adipokines to maintain energy homeostasis. Asprosin is a new type of adipokine, and its relationship with obesity remains controversial. There are a few reports on the effect of long-term exercise on serum asprosin level. This study aimed to investigate the effects of body mass index (BMI) and exercise/sedentary habit on serum asprosin in male college students as well as the relationship between serum asprosin and body composition and related metabolic indicators and provided a basis for further exploration of the biological function of asprosin. Ninety-six male college students were classified into the sedentary habit group (SD; 48) and the special training experience group (ET; 48). Both groups included three subgroups of normal BMI, overweight, and obesity, with 16 people in each subgroup. One-way analysis of variance, analysis of covariance, and Pearson correlation analysis were performed. The results showed that serum asprosin levels in the obesity subgroup were significantly higher than those in the normal and overweight subgroups. Excluding BMI interference, there were no significant differences in serum asprosin between the SD and ET groups; however, there were significant differences in body composition, tumor necrosis factor-α, interleukin-6, and interleukin-10. Asprosin was positively correlated with BMI, body fat percentage, visceral fat area, fasting insulin, insulin resistance homeostasis model, total cholesterol, low-density lipoprotein, tumor necrosis factor-α, interleukin-6, and leptin levels and was negatively correlated with relative lean body mass, relative skeletal muscle mass, high-density lipoprotein, and interleukin-10, and adiponectin levels. In conclusion, serum asprosin is closely related to body weight, body composition, glucose and lipid metabolism, inflammatory response, and fat hormones. Long-term exercise training cannot prevent BMI increase from increasing serum asprosin level. If the influence of BMI is excluded, long-term exercise training does not affect serum asprosin.

Monitoring calf circumference: changes during prolonged constrained sitting

Prolonged sitting has been associated with negative health effects; however, short-term time-varying exposure and response data is lacking. Twenty-two young and healthy participants were seated for 2 hours with the instruction to avoid the confounding effects of large leg movements while calf circumference, perceived discomfort, and lower limb muscle activity were collected. Calf circumference increased significantly (0.90 ± 0.32 cm) during sitting with no statistical differences between sexes. Perceived discomfort increased significantly over time in the low back and gluteal regions (p = 0.001-0.072, η_p²=0.080-0.360). On average, it took 20.31 ± 10.87 minutes of walking for calf measures to return to pre-sitting baseline. These results suggest that sitting for 2 hours without activity breaks may not be advisable and that recovery may take longer than expected. The exposure/response data from this study may be helpful in the design of future studies, with a larger and more general population, aiming to better define recommended duration/activity ratios for sitting-focused occupations. Practitioner summary: Leg swelling is a concern in prolonged sitting. In this study of young, healthy participants, we found a 2 hour constrained sitting exposure (controlling for large leg movements) induced significant increases in calf circumference that took an average of 20.31 ± 10.87 min of walking to return to baseline.Abbreviations: FMD: flow-mediated dilation, GSC: gastrocnemius; TA: tibialis anterior; EMG: electromyography; VAS: visual analog scale; MVC: maximum voluntary contractions.

Executive summary of evidence and consensus-based clinical practice guideline for management of obesity and overweight in postpartum women: An AIIMS-DST initiative

INTRODUCTION

Postpartum obesity is a public health concern. There is a need to counsel women about their postpartum weight management, accounting for various barriers they face. Limited literature in the Indian context underscored the need to develop the clinical practice guideline to be used by healthcare providers in Indian healthcare settings.

METHODS

The guideline was formulated by following the standardised methodology proposed by the National Health and Medical Research Council. Various steps such as identification of the patient population, assembly of the guideline development groups, identification of the key clinical questions, guideline development methods, grading the quality of evidence and recommendations and guideline translation were carried out to develop and validate the clinical practice recommendations.

RESULTS

The evidence and consensus-based clinical practice guideline has been developed, providing recommendations for key topics of interest for first-line treatment of obesity (lifestyle-related management). Recommendations focus on screening and initiating discussion with overweight and obese postpartum women as well as those who had normal pre-pregnancy body mass index but have retained excessive weight in the postpartum period. Recommendations highlight the evaluation and management of dietary, physical activity and breastfeeding behaviour. Recommendations also account for behavioural modification techniques to improve adherence to the prescribed weight management advice. Duration and frequency of follow-ups as well as the advice to be disseminated have also been discussed in the recommendations.

CONCLUSION

The guideline provides clinical practice points that can be used by healthcare providers, postpartum women and policymakers for opportunistic screening and management of postpartum obesity.

Changes in Physical Activity and Sedentary Behavior before and during the COVID-19 Pandemic: A Swedish Population Study

Governments have enforced measures to limit the spread of COVID-19 with varying degrees of success, which could affect people’s physical activity (PA) and sedentary behavior. This study aimed to examine changes in PA levels, types of PA, and sedentary behavior in the Swedish population before and during the COVID-19 pandemic. Associations between changed PA levels and demographical and behavioral determinants were also investigated. In December 2020, 1035 individuals (18–79 years old) completed a survey about their PA and sedentary behavior before and during the pandemic. Factors influencing their PA were also explored. Fifty-one percent of the sample reported reduced total PA, 18% had no change, and 31% increased their PA. Overall, organized PA decreased the most and sedentary behavior increased. The youngest and oldest age groups reported the greatest reduction in PA, while middle-aged groups reported the most increased PA. Men reported a larger increase in sedentary behavior than women. Mental and physical capability was associated with change in PA. In conclusion, this study indicates that, during the COVID-19 pandemic, the majority of the Swedish population have decreased PA levels with a concurrent increase in sedentary behavior, which may have negative health consequences. Interventions are recommended to address both PA and sedentary behavior, specifically to strengthen people’s ability to perform PA and focusing on the youngest and oldest age groups.

Sedentary time and its association with risk of cardiovascular diseases in adults: an updated systematic review and meta-analysis of observational studies

BACKGROUND

Epidemiological studies assessing the association between sedentary time and cardiovascular diseases (CVD) risks have been published at a rapid pace in recent years, which makes the periodic review of knowledge essential. Furthermore, much of the early and ongoing work used screen time as a marker of total sedentary time, which may weaken the association between sedentary time and CVD risks.

OBJECTIVE

To update evidence on CVD risks associated with different types of sedentary time, especially total sedentary time and screen time, and to explore as a marker of total sedentary time, whether screen time had similar CVD risks with total sedentary time.

METHODS

PRISMA guideline was followed for the performing and reporting of this systematic review and meta-analysis. Three independent researchers searched eight electronic databases and two clinical trial registries for all studies published between January 2015 and December 2021 that assessed the association between sedentary time and CVD risks in adults. A standardized form was used for data extraction and collection. Wilmot and colleagues' modified tool was used for quality assessment. The categorical association was assessed by comparing the pooled effect sizes for CVD risks associated with the highest and the lowest sedentary time categories across included studies. Stata 16.0 and Review Manager 5.3 were used for all statistical analyses, P ≤ 0.05 was considered as statistically significant.

RESULTS

Seventeen prospective cohort studies and two cross-sectional studies with 145,1730 participants and over 48,668 CVD cases and deaths were included. Two included studies measured sedentary time with the accelerometer, 16 studies with self-reported questions, and one study with both the accelerometer and self-reported questions. CVD outcomes were self-reported in two included studies and objectively adjudicated through medical records or death certifications in 17 studies. Compared with the lowest total sedentary time category (median duration, 2.75 h/d), participants in the highest category (median duration, 10.5 h/d) had an increased risk of CVD morbidity (pooled RR, 1.24; 95% CI, 1.21-1.27). Compared with the lowest total sedentary time category (median duration, 2.98 h/d), participants in the highest category (median duration, 10.2 h/d) had an increased risk of CVD mortality (pooled HR, 1.29; 95% CI, 1.13-1.47). The association between screen time and CVD risks was similar to total sedentary time with the cut-off point of 5-6 h/d. The associations between occupational sitting time, leisure sedentary time, and CVD risks stayed inconclusive.

CONCLUSION

Total sedentary time and screen time are both associated with cardiovascular health. As a marker of total sedentary time, screen time over 5-6 h/d had similar CVD risks with total sedentary time over 10-11 h/d.

Association between sitting-time at work and incidence of erosive esophagitis diagnosed by esophagogastroduodenoscopy: a Korean cohort study

Background

Most previous longitudinal studies on lifestyle and gastroesophageal reflux disease (GERD) have focused on physical activity rather than sitting time. The main purpose of this study was to investigate the relationship between prolonged sitting time and the development of erosive esophagitis (EE).

Methods

A self-report questionnaire was used for measuring sitting time in the Kangbuk Samsung Health Study. Sitting time was categorized into four groups: ≤ 6, 7–8, 9–10, and ≥ 11 hours/day. Esophagogastroduodenoscopy (EGD) was performed by experienced endoscopists who were unawared of the aims of this study. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the development of EE were estimated using Cox proportional hazards analyses with ≤ 6 hours/day sitting time as the reference.

Results

There were 6,524 participants included in the study. During a mean follow-up of 3.14 years, 2,048 incident cases developed EE. In age- and sex-adjusted models, the HR in the group sitting ≥ 11 hours per day compared ≤ 6 hours per day was 0.88 (95% CI: 0.76–0.99). After further adjusting for alcohol intake, smoking status, educational level, history of diabetes, and history of dyslipidemia, sitting time was still significantly related to the risk of EE (HR, 0.87; 95% CI: 0.76–0.98). After further adjustment for exercise frequency, this association persisted (HR, 0.86; 95% CI: 0.76–0.98). In subgroup analysis by obesity, the relationship between sitting time and EE was only significant among participants with body mass index < 25 kg/m² (HR, 0.82; 95% CI: 0.71–0.95).

Conclusions

Generally, prolonged sitting time is harmful to health, but with regard to EE, it is difficult to conclude that this is the case.

Factors Associated With Lower Respiratory Tract Infection Among Chinese Students Aged 6-14 Years

AIMS

We employed machine-learning methods to explore data from a large survey on students, with the goal of identifying and validating a thrifty panel of important factors associated with lower respiratory tract infection (LRTI).

METHODS

Cross-sectional cluster sampling was performed for a survey of students aged 6-14 years who attended primary or junior high school in Beijing within January, 2022. Data were collected via electronic questionnaires. Statistical analyses were completed using the PyCharm (Edition 2018.1 x64) and Python (Version 3.7.6).

RESULTS

Data from 11,308 students (5,527 girls and 5,781 boys) were analyzed, and 909 of them had LRTI with the prevalence of 8.01%. After a comprehensive evaluation, the Gaussian naive Bayes (gNB) algorithm outperformed the other machine-learning algorithms. The gNB algorithm had accuracy of 0.856, precision of 0.140, recall of 0.165, F1 score of 0.151, and area under the receiver operating characteristic curve (AUROC) of 0.652. Using the optimal gNB algorithm, top five important factors, including age, rhinitis, sitting time, dental caries, and food or drug allergy, had decent prediction performance. In addition, the top five factors had prediction performance comparable to all factors modeled. For example, under the sequential deep-learning model, the accuracy and loss were separately gauged at 92.26 and 25.62% when incorporating the top five factors, and 92.22 and 25.52% when incorporating all factors.

CONCLUSIONS

Our findings showed the top five important factors modeled by gNB algorithm can sufficiently represent all involved factors in predicting LRTI risk among Chinese students aged 6-14 years.

Sedentary Behavior in U.S. Adults: Fall 2019

PURPOSE

Higher levels of sedentary behavior are associated with early mortality, but the distribution of sedentary time by classes of behavior and demographic groups is poorly described in U.S. adults. To quantify the amount and sources of sedentary time in U.S. adults, we conducted a nationwide survey using a novel validated self-administered previous-day recall method and compared these values with a commonly used sitting time question.

METHODS

Participants from the AmeriSpeak panel 20 to 75 yr of age (N = 2640) completed up to two activities completed over time in 24 h (ACT24) previous-day recalls. Recalls were conducted on randomly selected days in October and November 2019. Survey sample designs were applied to reflect the U.S. population.

RESULTS

Mean age was 45.3 yr, 51% were female, 67% non-Hispanic White, and 37% had a body mass index of ≥30 kg·m-2. U.S. adults reported a mean 9.5 h·d-1 of sedentary time (95% confidence interval = 9.4, 9.7 h·d-1), which was 34% more than reported using a common surveillance measure (P < 0.01). Most daily sedentary time was accumulated in the leisure and work life domains, with leisure accounting for 47% (4.3 h·d-1, 95% confidence interval = 4.2, 4.5 h·d-1) of the total sedentary time. Eighty-two percent of leisure time was spent sedentary, mainly watching television/videos or engaged in Internet/computer use.

CONCLUSIONS

U.S. adults appear to spend more time in sedentary behavior than previously thought, and the majority of this time is accumulated at work and in leisure time. Reducing sedentary screen time during leisure in favor of physically active could be an important intervention target in the effort to increase physical activity in U.S. adults.

Frailty and falls in people living with multiple sclerosis

OBJECTIVE

To explore the association between frailty and history of falls in people living with multiple sclerosis (MS).

DESIGN

Secondary analysis.

SETTING

University research laboratories in the United States and Israel.

PARTICIPANTS

118 people with relapsing-remitting MS [age=48.9 years (SD=10.0); 74.6% female; expanded disability status scale (EDSS) range=1.0-6.0] were studied in this cross-sectional analysis.

INTERVENTION

Not applicable.

MAIN OUTCOMES

A frailty index was calculated from 40 health deficits by following standard validated procedures. The number of falls (12-month history) was recorded.

RESULTS

Overall, 33.9%, 29.7%, and 36.4% of participants were classified as non-frail, moderately frail, and severely frail, respectively. The frailty index was significantly correlated (ρ=0.37, p<0.001) with higher scores on the EDSS. In univariable negative binomial regression analysis, the frailty index was associated with a higher number of falls (IRR=3.33, 95%CI[1.85-5.99], p<0.001). After adjustment for age, gender and EDSS, frailty remained strongly associated with history of falls (IRR=2.78, 95%CI[1.51-5.10], p=0.001).

CONCLUSION

The current study identifies a significant relationship between frailty and history of falls in MS, independent of age, gender, and disease severity. These findings support the notion that frailty is a syndrome related to, but independent of, disability in MS.

Association between physical and mental health variables among software professionals working at home: a secondary analysis

TRIAL REGISTRATION

Clinical Trials Registry India identifier CTRI/2021/03/032146.

Effects of Prolonged Sitting with or without Elastic Garments on Limb Volume, Arterial Blood Flow, and Muscle Oxygenation

Supplemental digital content is available in the text.

Purpose

The physiological response induced by acute prolonged sitting is not fully understood. Therefore, we examined the effects of 8-h constant sitting on microcirculation and associated factors in the lower extremity among healthy males. We also evaluated the protective effects of lower-pressure thigh-length elastic compression garments on these parameters.

Methods

Nine healthy males (age, 22.6 ± 1.4 yr; body mass index, 22.4 ± 1.8 kg·m⁻²) completed the 8-h constant sitting experiment. Following baseline measurements, each subject was randomized to wear a lower-pressure elastic garment on the right or left leg from the inguinal region to the ankle joint, with the noncompressed contralateral leg as a control. Circumferences of the calf and malleolus, extracellular water contents, blood flow and shear rate of the dorsal metatarsal artery, and oxygen dynamics in the gastrocnemius muscles were measured in both extremities before and during 8-h constant sitting.

Results

Compared with baseline values, 8-h constant sitting caused enlargement of circumferences (calf, 2.4% ± 0.7%; malleolus, 2.7% ± 1.4%), retention of extracellular water in lower extremity muscles (10.1% ± 1.78%), deterioration of the blood flow (61.4% ± 16.2% of baseline) and shear rate of the dorsal metatarsal artery, and decrease in oxygenated hemoglobin and total hemoglobin levels in the gastrocnemius muscle (P < 0.05, respectively). When subjects wore the lower-pressure thigh-length compression garment, a significant reduction of these effects was observed (P < 0.05, for all).

Conclusions

Prolonged sitting for 8 h induced edema, as well as deterioration of the arterial blood flow, shear rate, and microcirculation in lower limb muscles. Conversely, application of the lower-pressure elastic garment successfully prevented the pathophysiological deterioration associated with prolonged sitting.

Designing a remote professional development course to support teacher customization in science

This study reports on the design, implementation, and impact of a remote professional development (PD) course for secondary school teachers who were transitioning to remote instruction during the COVID-19 pandemic. We designed technology innovations to strengthen the previously successful in-person course. The innovations support teachers to customize an instructional unit by setting and revising goals based on evidence from their students’ prior work on the unit. A Curriculum Visualizer makes the pedagogy of the unit visible and guides planning for customization. Carefully curated small group activities using Zoom breakout rooms ensure that each teacher could share their thoughts, ideas, and impressions with other teachers. Participants were 23 science teachers from 12 different schools in a western U.S. state. We developed rubrics to code customization goals, plans, and moves using bottom-up methods and iterative refinement. Reflections on student work and use of the Curriculum Visualizer enabled teachers to set and refine customization goals and make evidence-based and pedagogy-aligned customization decisions that enhanced the interactive learning opportunities for their students. Our results reinforce the C-b model proposed by Sailer et al. (this issue) by illustrating the value of using technology to support collaborative, interactive PD activities.

Too Much Sitting: A Serious 21st Century Health Risk

While weekly moderate-to-vigorous physical activity (MVPA) is considered a well-established key determinant for regulating weight and reducing risks of obesity and associated noncommunicable diseases, MVPA alone may not be enough to offset excessive sitting time. This integrative literature review aims to advance the discussion about sedentary behavior as a significant independent health risk for obesity and associated noncommunicable diseases, to increase awareness, to synthesize important evidence on sedentary behavior and a number of negative health outcomes, and to present the application of a whole-day approach to physical activity as a feasible strategy to promote health.

Sedentary behavior is associated with chronic obstructive pulmonary disease: A generalized propensity score-weighted analysis

Chronic obstructive pulmonary disease (COPD) is the fourth and third leading cause of death worldwide and in China, respectively. Sedentary behavior has been shown to increase the risk of respiratory disease, such as asthma. However, the relationship between sedentary behavior and COPD is unclear. This study aimed to investigate the association between sedentary behavior and COPD.Data was extracted from the 2018 a large-scale cross-sectional study of Chronic Disease and Lifestyle Population Survey in Sichuan Province of China, in which sedentary behavior and chronic diseases were self-reported according to medical records. The association between sedentary behavior on risk of COPD was estimated using multivariable regression model in non-matching cohorts and generalized propensity score-weighted (GPSW)cohorts, respectively, controlling for potential confounders.Individuals who remained sedentary for more than 7 hours per day were more likely to have COPD than the control group (<3 hours) both in conventional multivariate logistic regression analysis (OR = 2.020, 95%CI: 1.575-2.585, P < .001) and GPSW analysis (OR = 2.381, 95%CI: 1.778-3.188, P < .001). After GPSW and the sensitivity analysis using refined smoking variable further found a dose-effect between sedentary behavior and COPD, with 1.242 (95%CI: 1.006-1.532, P < .05) times risk of COPD in those sedentary behavior of more than 5 hours per day (GPSW) and 1.377 (95%CI: 1.092-1.736, P < .05) times risk in those sedentary behavior above 5 hours per day (sensitivity analysis), comparing with the control group.Sedentary behavior is independently associated with increased risk of COPD, adjusting for other confounders. The findings of this study have important implications for future research and public health guidance. Reducing sedentary time may have a significant role in COPD prevention.

The Influence of Power on Leisure: Implications for Inclusive Leisure Services

Many people experience domination as they encounter oppression and marginalization because of power differentials limiting their leisure. We rely on Foucault for guidance to examine connections between power and opportunities for people to be included in leisure and recognize that, like Foucault, we experience privilege. Considering such privilege, we explore power and people connections, scrutinize ways power influences leisure, and examine methods to promote or resist power to increase leisure. Drawing on the analysis of power and leisure, we examine how discourse influences leisure and identify ways to facilitate inclusive leisure. We consider these aspects via Allen’s (1998) modalities of power-over, power-to, and power-with. Analyzing these modalities, we address barriers to leisure associated with power, strategies people use to engage in resistance through leisure, and ways inclusive leisure might occur. We conclude that each person can make positive contributions and offer inclusive leisure.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Reproducibility of Accelerometer and Posture-derived Measures of Physical Activity

PURPOSE

The present study estimated the long-term reproducibility of accelerometer-based measures over 6 months in adults and the implications for statistical power, and attenuation in regression coefficients for future activity-disease studies.

METHODS

We used data from 914 adults in the Interactive Diet and Activity Tracking in AARP study. Participants wore an activPAL 3 (AP) and an ActiGraph GT3X (AG) twice, 6 months apart. AP measures included time spent sitting or lying, standing, and stepping, whereas AG measures included time spent in sedentary, light, and moderate-to-vigorous physical activity (PA). Reproducibility of each metric and implications for epidemiological studies were determined based on intraclass correlation coefficients (ICC; 95% confidence interval).

RESULTS

The ICC values for AP estimates were 0.58 (95% confidence interval, 0.53-0.63) for sitting, 0.62 (0.57-0.67) for standing, and 0.57 (0.51-0.62) for stepping. The ICC values for AG were 0.56 (0.50-0.61) for sedentary, 0.54 (0.49-0.60) for light PA, and 0.58 (0.52-0.63) for moderate-to-vigorous PA. Modeling showed that increasing the number of replicate administrations to two or three resulted in the most noticeable increases in ICC values, statistical power, and reductions in attenuation coefficients. For example, administering the AP twice reduced within-subject variability by half and resulted in an increase in the ICC associated with sitting time from 0.58 to 0.74. Similar comparisons for AG and measure of sedentary time resulted in an increase in ICC values from 0.56 to 0.72. Increasing the number of replicate administrations from one to two reduced the attenuation in activity-outcome associations from 40% to 25%.

CONCLUSION

Accelerometer-based classifications of activity are moderately stable over time, but there is considerable within-subject variability that needs to be considered when estimating usual activity in future studies.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Accounting for the Nutritional Context to Correctly Interpret Results from Studies of Exercise and Sedentary Behavior

There is a wealth of research lauding the benefits of exercise to oppose cardiometabolic disease such as diabetes, CVD and hypertension. However, in the great majority of these studies, the nutritional context (energy balance, deficit, or surplus) has been ignored, despite its profound effect on responses to both exercise and inactivity. Even a minor energy deficit or surplus can strongly modulate the magnitude and duration of the metabolic responses to an intervention; therefore, failure to account for this important confounding variable obscures clear interpretation of the results from studies of exercise or inactivity. The aim of this review is to highlight key lessons from studies examining the interaction between exercise and sedentary behavior, energy status, and glucose and insulin regulation. In addition to identifying notable problems, we suggest a few potential solutions.

Behavioral and Physiological Health-Related Risk Factors in College Students

The purpose of this study was to assess the behavioral and physiological health-related risk factors in college students. A cross-sectional study was conducted in 1620 college students (21.3 ± 1.7 years, 897 males, and 723 females). Physical activity (PA), sitting time, body composition, cardiorespiratory fitness (CRF), muscular endurance (ME), and blood test were assessed. In the total sample, 15.2% were not meeting PA guidelines, 33% were sedentary, 13.3% were obese, 10.7% had low CRF, 36.8% had poor ME, 33.7% had dyslipidemia and 5.9% presented with prediabetes. Obesity and poor CRF were more prevalent in male students, whereas inactivity was more prevalent in female students. Individuals with poor CRF were more likely to be obese (odds ratio = 5.2, 95% CI = 3.5-7.8, P = .007 for male students, and 9.4, 95% CI = 1.5-57.8, P = .021 for female students). Sitting time positively correlated with fat percentage (fat%) and inversely with lean body mass (LBM) in male students, whereas ME inversely correlated with fat% and positively with LBM in female students. Although most students were active, significant prevalence of health-related risk factors were observed. Sedentary behavior and poor fitness were associated with a compromised body composition in both sexes. Improving fitness and reducing sedentary behavior in college students could be a public health strategy for health promotion and chronic diseases prevention.

Physical Activity, Sitting Time, and Risk of Myelodysplastic Syndromes, Acute Myeloid Leukemia, and Other Myeloid Malignancies

INTRODUCTION

There is limited research on associations of moderate-to-vigorous physical activity (MVPA) and sitting with risk of myeloid neoplasms (MN) or MN subtypes. We examined these associations in the Cancer Prevention Study-II Nutrition Cohort.

METHODS

Among 109,030 cancer-free participants (mean age 69.2, SD 6.1 years) in 1999, 409 were identified as having been diagnosed with a MN [n = 155 acute myeloid leukemia (AML), n = 154 myelodysplastic syndromes (MDS), n = 100 other ML] through June 2013. Cox proportional hazards regression was used to calculate multivariable adjusted hazard ratios (HR) and 95% confidence intervals (CI) for associations of MVPA (MET-h/wk) and sitting (h/d) with risk of all MN, myeloid leukemia only, MDS, and AML.

RESULTS

Compared with insufficient MVPA [>0-<7.5 metabolic equivalent hours/week (MET)-h/wk], the HR (95% CI) for meeting physical activity guidelines (7.5-<15 MET-h/wk MVPA) and risk of MN was 0.74 (95% CI, 0.56-0.98) and for doubling guidelines (15-<22.5 MET-h/wk) was 0.75 (0.53-1.07); however, there was no statistically significant association for higher MVPA (22.5+ MET-h/wk, HR, 0.93; 95% CI, 0.73-1.20). Similarly, meeting/doubling guidelines was associated with lower risk of MDS (HR, 0.57; 95% CI, 0.35-0.92/HR, 0.51; 95% CI, 0.27-0.98), but there was no association for 22.5+ MET-h/wk (HR, 0.93; 95% CI, 0.63-1.37). MVPA was not associated with risk of myeloid leukemia or AML. Sitting time was not associated with risk of any outcome.

CONCLUSIONS

These results suggest that there may be a nonlinear association between MVPA and risk of MDS and possibly other MN.

IMPACT

Further studies are needed to better understand the dose-response relationships between MVPA and risk of MDS, a highly fatal and understudied cancer.

Elementary school classroom physical activity breaks: student, teacher, and facilitator perspectives

Current physical activity (PA) guidelines recommend that children accumulate at least 60 min of PA each day, and that adults should collaborate across sectors to increase opportunities for PA. Implementing brief classroom PA breaks (CPABs) is one way to help increase daily PA. The primary purpose of this study was to determine perceptions of a 14-wk CPAB program among elementary school children, in the first through fourth grades ( n = 254), at a suburban elementary school, and their teachers ( n = 18). The CPAB program was implemented by university exercise science students, and student and teacher perceptions were assessed through surveys. The children reported that the CPABs were very fun (86%), provided them with a nice break during the school day (88%), were very good for their health (94%), helped them feel more ready to learn (71%), and learn better (50%). The teachers reported that the students really enjoyed the CPABs (100%), that encouraging students to be physically active was either very important (83%) or important (17%), and that they were either very confident (72%) or confident (28%) that they themselves could lead the CPABs. No teacher reported that the CPABs hindered classroom learning. CPABs appear to be enjoyable to both students and teachers, easy to administer, and supportive of learning. Recommendations for improvements within the present collaboration were minimal and could be easily addressed with firmer entrenchment of the program. This collaboration was beneficial and fun for the vast majority involved, and others are urged to implement similar programs.

Energy Expenditure of a Single Sit-to-Stand Movement with Slow Versus Normal Speed Using the Different Frequency Accumulation Method

Background and objectives: The purpose of this study was to compare the energy expenditures (EE) of a single sit-to-stand (STS) movements with slow and normal speeds using a multi-stage exercise test. Materials and Methods: Twelve young males, aged 21–27 years (age, 23.0 ± 1.7 years; height, 171.2 ± 6.1 cm; weight, 64.3 ± 5.6 kg), performed repeated 3-s stand-up and 3-s sit-down (slow) or 1-s stand-up and 1-s sit-down (normal) movement on two different days with random order. All the participants completed multi-stage tests at different STS frequencies per minute. The slope and intercept of the linear regression relationship between the EE (kcal/min) and the STS frequency were obtained, and the slope of the regression was quantified as the EE of an STS. Results: The metabolic equivalents (METs) of the STS-slow was 4.5 METs for the frequency of 10 times/min (in total 1 min), and the net EE was 5.00 ± 1.2 kcal/min. The net EE of the STS-slow was 0.37 ± 0.12 kcal, which was significantly greater than that during the STS-normal (0.26 ± 0.06 kcal). The difference between the EEs of the STS-slow and STS-normal was significantly greater in taller and heavier subjects. Conclusions: We concluded that the intensity of STS-slow movement is moderate, and the EE during an STS-slow (0.37 ± 0.12 kcal) is higher than that during an STS-normal (0.26 ± 0.06 kcal). Our study results will help exercise and/or health professionals prescribe physical activity programs using STS movement for healthy young population groups.

Sedentary behavior and physiological health determinants in male and female college students

BACKGROUND

Sedentary behaviors are associated with numerous adverse physiological health outcomes, morbidity and mortality, although with limited knowledge in young adults.

AIM

To assess the association between sedentary behavior, muscular strength and body composition in male and female young adult college students.

METHODS

A cross-sectional pilot study was conducted among 94 college students (20.2 ± 1.6 years, 46 males and 48 females) from a University in the Mid-Atlantic region, US. Students were assessed for sedentary behavior, physical activity and objective physiological variables including lean body mass (LBM), fat% and muscular strength [1-Repetition Maximum (1-RM)]. Descriptive statistics and linear regression analysis were conducted.

RESULTS

Sedentary behavior (sitting time ≥ 6 h/day) was prevalent in 69% of females and in 46% of males, p = .036, although most students (84-94%) met the physical activity recommendations. Sitting time inversely correlated with LBM (r = -0.58, p = .01) and trending for positive correlation with fat% in females, whereas in males, sitting time inversely correlated with 1-RM upper body strength (r = -0.46, p = .017). Female students who sat ≥7.5 h/day had approximately 10-fold increased chance of being obese [odds ratio = 9.6, 95% confidence interval (1.5 to 62.7), p = .019] compared to non-sedentary.

CONCLUSIONS

Although most students were physically active, considerable prevalence of sedentary behavior was observed. The novel findings showed that, sedentary behavior was associated with compromised physiological health determinants of body composition in females and muscular strength in males. Reducing sedentary behavior among active college students could be a public health strategy for health promotion and chronic disease prevention.

Is iron deficiency modulating physical activity in COPD?

There is evidence that iron plays a key role in the adequate functioning of skeletal muscle. While it has been demonstrated that nonanemic iron deficiency (NAID) affects exercise tolerance and response to exercise training in patients with COPD, the impact on daily physical activities (DPAs) remains unknown. Eighteen COPD patients with NAID (ferritin <100 ng/mL or ferritin 100–299 ng/mL with a transferrin saturation <20%) and 18 COPD patients without this abnormality, matched for age, gender, and the degree of airflow limitation (control group), were enrolled to the study. The primary outcome was the level of DPA assessed by accelerometers. Patients were (mean [SD]) 66 (7) years and were mostly male (70%) and former smokers (52%). Their forced expiratory volume at 1 second was 41 (16)% predicted, carbon monoxide diffusing capacity was 47 (14)% predicted and oxygen arterial pressure reached 70 (11) mmHg. DPA and the number of steps per day were lower in NAID COPD patients compared with controls (physical activity level 1.39 vs 1.59, P<0.05; and 4,402 vs 6,975 steps/day, P<0.05, respectively). The percentage of patients with increased time spent sitting per day (>6 hours) was higher in patients with NAID compared with controls (73% vs 37%, P<0.05). In addition, the percentage of patients doing moderate to vigorous physical activity per day (>3 metabolic equivalents of task, at least 30 minutes) was lower in this group (66% vs 100%, P<0.05). The presence of iron deficiency was associated with reduced DPA in COPD patients. Further studies are needed to evaluate iron reposition and their impact on the level of physical activity in these patients.