BACKGROUND: The terms sedentary behavior and physical inactivity have been confusingly mixed. Although the association between physical inactivity and mortality has been shown previously in subjects with COPD, this association had not yet been investigated with regard to sedentarism. The aim of this work was to investigate the impact of sedentary behavior on mortality of subjects with COPD and to propose a cutoff point of sedentarism with prognostic value. METHODS: In this retrospective cohort study, sedentary behavior was assessed with 2 activity monitors (DynaPort and Sensewear armband) in 101 subjects with COPD from 2006 to 2011. Vital status was then ascertained in 2015. The following 6 variables of sedentary behavior were analyzed: average of metabolic equivalent of task (MET)/d (reflecting intensity); time spent/d lying, sitting, and lying + sitting (reflecting duration of sedentary postures); and time spent/d in activities requiring <1.5 MET and <2 MET (reflecting intensity and duration of sedentary time). Cutoff points for sedentarism and their respective prognostic values were investigated for each variable. RESULTS: Forty-one subjects (41%) died over a median (interquartile range) follow-up period of 62 (43–88) months. After adjusting for potential confounders in the Cox regression model, cutoff points from variables that combine duration of sedentary time and intensity <1.5 MET or <2 MET were associated with the increased risk of mortality. The strongest independent cutoff for predicting mortality was ≥8.5 h/d spent in sedentary activities <1.5 MET (area under the curve 0.76; hazard ratio 4.09, 95% CI 1.90–8.78; P < .001). CONCLUSIONS: Sedentary behavior was an independent predictor of mortality in subjects with COPD, even adjusting for moderate-to-vigorous physical activity and a number of other variables. Mortality was higher in subjects with COPD who spend ≥8.5 h/d in activities requiring <1.5 MET. These findings may open room for future studies aiming at decreasing sedentary time as a promising strategy to reduce mortality risk in subjects with COPD.

We described physical activity measures and hourly patterns in patients with chronic obstructive pulmonary disease (COPD) after stratification for generic and COPD-specific characteristics and, based on multiple physical activity measures, we identified clusters of patients. In total, 1001 patients with COPD (65% men; age, 67 years; forced expiratory volume in the first second [FEV₁], 49% predicted) were studied cross-sectionally. Demographics, anthropometrics, lung function and clinical data were assessed. Daily physical activity measures and hourly patterns were analysed based on data from a multisensor armband. Principal component analysis (PCA) and cluster analysis were applied to physical activity measures to identify clusters. Age, body mass index (BMI), dyspnoea grade and ADO index (including age, dyspnoea and airflow obstruction) were associated with physical activity measures and hourly patterns. Five clusters were identified based on three PCA components, which accounted for 60% of variance of the data. Importantly, couch potatoes (i.e. the most inactive cluster) were characterised by higher BMI, lower FEV₁, worse dyspnoea and higher ADO index compared to other clusters ( p < 0.05 for all). Daily physical activity measures and hourly patterns are heterogeneous in COPD. Clusters of patients were identified solely based on physical activity data. These findings may be useful to develop interventions aiming to promote physical activity in COPD.

Asthma is a heterogeneous and complex disease, and a description of asthma phenotypes based on extrapulmonary treatable traits has not been previously reported.The objective of this study was to identify and characterise clusters based on clinical, functional, anthropometrical and psychological characteristics in participants with moderate-to-severe asthma.This was a cross-sectional multicentre study involving centres from Brazil and Australia. Participants (n=296) with moderate-to-severe asthma were consecutively recruited. Physical activity and sedentary time, clinical asthma control, anthropometric data, pulmonary function and psychological and health status were evaluated. Participants were classified by hierarchical cluster analysis and the clusters compared using ANOVA, Kruskal­–Wallis and Chi-squared tests. Multiple logistic and linear regression models were performed to evaluate the association between variables.We identified four clusters: 1) participants with controlled asthma who were physically active; 2) participants with uncontrolled asthma who were physically inactive and more sedentary; 3) participants with uncontrolled asthma and low physical activity, who were also obese and experienced anxiety and/or depression symptoms; and 4) participants with very uncontrolled asthma who were physically inactive, more sedentary, obese and experienced anxiety and/or depression symptoms. Higher levels of sedentary time, female sex and anxiety symptoms were associated with increased odds of exacerbation risk, while being more active showed a protective factor for hospitalisation. Asthma control was associated with sex, the occurrence of exacerbation, physical activity and health status.Physical inactivity, obesity and symptoms of anxiety and/or depression were associated with worse asthma outcomes, and closely and inextricably associated with asthma control. This cluster analysis highlights the importance of assessing extrapulmonary traits to improve personalised management and outcomes for people with moderate and severe asthma.

Low back pain is common during pregnancy. Lumbar stabilization and stretching exercises are recommended to treat low back pain in the general population. However, few studies have applied the effects of these two interventions in pregnant women with low back pain. To compare the effects of lumbar stabilization and stretching exercises for the treatment of gestational low back pain. A pilot randomized clinical trial. Laboratory of Functional Evaluation and Human Motor Performance and physical therapy clinics. Initially, 30 pregnant women with low back pain were recruited, of which 24 met the following inclusion criteria: being between 19-29 weeks of gestation; being in prenatal clinical follow-up; having nonspecific mechanical low back pain started in pregnancy; not participating in specific low back pain treatment in the last 3 months. A total of 20 women completed the study (10 each group). The main outcome measures were clinical (pain by Visual Analogue Scale (VAS) and McGill Pain Questionnaire and disability by Roland Morris Questionnaire), and secondary outcome measures were: postural balance (force platform); muscle activation level of multifidus, iliocostalis lumborum, rectus abdominis and external abdominal oblique (electromyography). The women were randomized into two groups for 6 weeks of intervention twice a week for a 50-minute treatment: 1) lumbar stabilization exercise protocol and 2) stretching exercise protocol. There was a significant reduction (P=0.03) in pain (1.68 in VAS and 4.81 for McGill questionnaire) for both interventions, but no change in disability score. In addition, both interventions were comparable for a significant improvement in postural stability (in mean d=0.77) for the velocity sway parameter, and significantly increased activation (P>0.05) of the external abdominal oblique muscle after intervention. Both modalities (lumbar stabilization and stretching) were efficient for pain reduction, improving balance and increasing one trunk activity muscle after 6 weeks of intervention in pregnant women with low back pain. The present study has implications, especially for clinical decision-making with regard to therapy choice in pregnant women with LBP to reduce pain and improve trunk function as measured through balance performance.