The impact of sleep duration on physical activity in daily life in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Despite the high prevalence of sleep disturbances in idiopathic pulmonary fibrosis (IPF), the relationship between physical activity in daily life (PADL) and sleep in this population remains unclear. OBJECTIVES: Investigate the impact of sleep on different domains of PADL in IPF and characterize their PADL profile. METHODS: Sixty-seven participants (thirty-three with IPF and thirty-four healthy subjects [control group]) were included. The subjects underwent assessments of pulmonary function, exercise capacity, respiratory and peripheral muscle strength, PADL, sleep, dyspnea, and health-related quality of life. PADL and sleep measures were assessed using an activity monitor (Actigraph®, wGT3x-BT). Associations between sleep and PADL were done using correlation and regression models. RESULTS: In the IPF, sleep duration at night associated significantly with step counts, sedentary, light, and moderate-to-vigorous physical activity (MVPA) (-0.82 ≤ R ≤ 0.43; p < .05 for all). Lung function and sleep partially explained PADL variables (0.19 ≤ R2 ≤ 0.65, p < .05 for all). Compared to controls, the IPF subjects presented lower step counts, less time spent in MVPA, standing position, and more time spent in lying position (p < .05, for all). CONCLUSIONS: Sleep duration is associated with PADL in IPF. The PADL profile of patients is worse than in control subjects.

Profile and determinants of daily physical activity objectively assessed in university students.

BACKGROUND: The aim of this study was to quantify and compare physical activity (PA) levels of university students from different fields of study, and to investigate its correlates. METHODS: 221 students (111 female, 20 [18-23] years), from different study fields were cross-sectionally assessed for daily PA (pedometer), cardiorespiratory fitness (20 m Shuttle Run Test-20mSRT), health-related quality of life (HRQoL), anxiety and depression symptoms. RESULTS: In general, 60% of the students were physically active (>8000 steps/day), presented good HRQoL and cardiorespiratory fitness, minimal symptoms of depression and moderate of anxiety. The highest PA level was observed in students from physical education and sport sciences, and the lowest in those from social sciences (median [IQR]: 9882 [8435-13510] versus 7593 [6070-9753] steps/day, respectively; P<0.01). Male students were more active than female. Steps/day was moderately associated with VO2max (r=0.42), VO2%pred (r=0.41) and distance achieved in the 20mSRT (r=0.43) (P<0.0001 for all), and weakly associated with anxiety symptoms (r=-0.20; P=0.004) and HRQoL domains (0.15

Validation of the Incremental Shuttle Walk Test as a Clinical End Point in Bronchiectasis.

BACKGROUND: A validated clinical end point is needed to assess response to therapies in bronchiectasis. OBJECTIVES: The goal of this study was to assess the reliability, validity, and responsiveness of the incremental shuttle walk test (ISWT) as a clinical end point in bronchiectasis. METHODS: In clinically stable patients (n = 30), the ISWT was performed twice, 6 months apart. Correlation between the St. George's Respiratory Questionnaire (SGRQ) and the ISWT (n = 94) was performed. The 1-year gentamicin study was reanalyzed to assess the area under the curve (percent change of ISWT with a ≥ 4 unit improvement in total SGRQ). ISWT was performed prior to and following 14 days of antibiotics for an exacerbation (94 oral courses and 30 IV courses, n = 124) and reanalysis of the 1-year gentamicin study (n = 57). RESULTS: The ISWT did not significantly change over 6 months while clinically stable. The ISWT correlated inversely with the SGRQ (rs = -0.60; P < .0001), Bronchiectasis Severity Index score (rs = -0.44; P < .0001), and sedentary time (rs = -0.48; P = .0007) but correlated with physical activity (rs = 0.42; P = .004). The area under the curve for percent change in ISWT with ≥ 4 unit improvement in SGRQ was 0.79 (95% CI, 0.66-0.91; P = .001). A threshold of 5% improvement in the ISWT had a 92% sensitivity but 50% specificity, and from the responsiveness studies would capture 73% of all patients. CONCLUSIONS: This study confirmed the ISWT to be reliable, valid, and responsive to change in patients with bronchiectasis. The authors propose that a minimum clinically important difference of 5% improvement in the ISWT would be a useful objective end point to assess therapies in bronchiectasis.

Home monitoring of breathing rate in people with chronic obstructive pulmonary disease: observational study of feasibility, acceptability, and change after exacerbation.

Telehealth programs to promote early identification and timely self-management of acute exacerbations of chronic obstructive pulmonary diseases (AECOPDs) have yielded disappointing results, in part, because parameters monitored (symptoms, pulse oximetry, and spirometry) are weak predictors of exacerbations. PURPOSE: Breathing rate (BR) rises during AECOPD and may be a promising predictor. Devices suitable for home use to measure BR have recently become available, but their accuracy, acceptability, and ability to detect changes in people with COPD is not known. PATIENTS AND METHODS: We compared five BR monitors, which used different monitoring technologies, with a gold standard (Oxycon Mobile®; CareFusion®, a subsidiary of Becton Dickinson, San Diego, CA, USA). The monitors were validated in 21 stable COPD patients during a 57-min "activities of daily living protocol" in a laboratory setting. The two best performing monitors were then tested in a 14-day trial in a home setting in 23 stable COPD patients to determine patient acceptability and reliability of signal. Acceptability was explored in qualitative interviews. The better performing monitor was then given to 18 patients recruited during an AECOPD who wore the monitor to observe BR during the recovery phase of an AECOPD. RESULTS: While two monitors demonstrated acceptable accuracy compared with the gold standard, some participants found them intrusive particularly when ill with an exacerbation, limiting their potential utility in acute situations. A reduction in resting BR during the recovery from an AECOPD was observed in some, but not in all participants and there was considerable day-to-day individual variation. CONCLUSION: Resting BR shows some promise in identifying exacerbations; however, further prospective study to assess this is required.

Application of Mixed Effects Limits of Agreement in the Presence of Multiple Sources of Variability: Exemplar from the Comparison of Several Devices to Measure Respiratory Rate in COPD Patients.

INTRODUCTION: The Bland-Altman limits of agreement method is widely used to assess how well the measurements produced by two raters, devices or systems agree with each other. However, mixed effects versions of the method which take into account multiple sources of variability are less well described in the literature. We address the practical challenges of applying mixed effects limits of agreement to the comparison of several devices to measure respiratory rate in patients with chronic obstructive pulmonary disease (COPD). METHODS: Respiratory rate was measured in 21 people with a range of severity of COPD. Participants were asked to perform eleven different activities representative of daily life during a laboratory-based standardised protocol of 57 minutes. A mixed effects limits of agreement method was used to assess the agreement of five commercially available monitors (Camera, Photoplethysmography (PPG), Impedance, Accelerometer, and Chest-band) with the current gold standard device for measuring respiratory rate. RESULTS: Results produced using mixed effects limits of agreement were compared to results from a fixed effects method based on analysis of variance (ANOVA) and were found to be similar. The Accelerometer and Chest-band devices produced the narrowest limits of agreement (-8.63 to 4.27 and -9.99 to 6.80 respectively) with mean bias -2.18 and -1.60 breaths per minute. These devices also had the lowest within-participant and overall standard deviations (3.23 and 3.29 for Accelerometer and 4.17 and 4.28 for Chest-band respectively). CONCLUSIONS: The mixed effects limits of agreement analysis enabled us to answer the question of which devices showed the strongest agreement with the gold standard device with respect to measuring respiratory rates. In particular, the estimated within-participant and overall standard deviations of the differences, which are easily obtainable from the mixed effects model results, gave a clear indication that the Accelerometer and Chest-band devices performed best.

Long-term effects of a program to increase physical activity in smokers.

BACKGROUND: Programs aimed at increasing physical activity in daily life (PADL) have generated growing interest to prevent the deleterious effects of physical inactivity. Recent literature has shown that a short-term protocol using pedometers increased PADL in smokers with normal lung function. However, the long-term effects of such a protocol were not yet studied. The objective of this study was to evaluate the results of 1-year follow-up after a program aimed at increasing PADL in smokers with normal lung function. METHODS: Twenty-four smokers were followed (15 men; mean [interquartile range (IQR)], 51 [41-57] years of age; BMI, 26 [22-29] kg/m2; 20 [20-30] cigarettes/d). Subjects were assessed at baseline, immediately after completion of the program, and 1 year later for PADL, lung function, 6-min walking distance (6MWD), smoking habits, quality of life, anxiety, and depression. The 5-month program used pedometers and informative booklets as interventions. RESULTS: The gains achieved after the program were maintained in the long term: steps/d (postprogram vs 1-year follow-up, mean [IQR]: 10,572 [9,804-12,237] vs 10,438 [9,151-12,862]); 6MWD (625 [530-694] m, 88 [81-97] % predicted vs 609 [539-694] m, 89 [81-96] % predicted), anxiety (34 [26-41] points vs 35 [36-47] points) and depression (6 [2-9] points vs 5 [2-11] points) (P > .05 for all). One year after the program, 20% of the subjects had quit smoking. CONCLUSIONS: In smokers with normal lung function, improvements in daily physical activity, exercise capacity, anxiety, and depression obtained through a 5-month program aimed at increasing physical activity are sustained 1 year after completion of the program. Furthermore, such a program can contribute to smoking cessation in this population.

Does the BODE index reflect the level of physical activity in daily life in patients with COPD?

OBJECTIVES: To study the relationship between the level of physical activity in daily life and disease severity assessed by the BODE index in patients with chronic obstructive pulmonary disease (COPD). METHODS: Sixty-seven patients with COPD (36 men) with forced expiratory volume in the first second (FEV(1)) of 39 (27-47)% predicted and age of 66 (61-72) years old were evaluated by spirometry, dyspnea levels (measured by the Medical Research Council scale, MRC) and by the 6-minute walking test (6MWT). The BODE index was calculated based on the body mass index (weight/height²), FEV(1), MRC and 6MWT, and then the patients were divided in four quartiles according to their scores (Quartile I: 0 to 2 points, n=15; Quartile II: 3 to 4 points, n=20; Quartile III: 5 to 6 points, n=23; Quartile IV: 7 to 10 points, n=9). Two activity monitors (DynaPort® and SenseWear®) were used to evaluate the level of physical activity in daily life. The Kruskal-Wallis test (Dunns's post-hoc test), the Mann-Whitney test and the Spearman Correlation Coefficient were used for statistical analysis. RESULTS: There were modest correlation between the BODE index and the time spent walking per day, the total daily energy expenditure and the time spent in moderate and vigorous activities per day (-0.32 ≤ r ≤ -0.47; p≤0.01 for all variables). When comparing the pooled quartiles I+II with III+IV, there were significant difference between the time spent walking per day, the total daily energy expenditure and the time spent in moderate activities per day (p≤0.05). CONCLUSION: The level of physical activity in daily life has a modest correlation with the classification of COPD severity assessed by the BODE index, reflecting only differences between patients with classified as mild-moderate and severe-very severe COPD.

Does the BODE index reflect the level of physical activity in daily life in patients with COPD? / O índice BODE reflete o nível de atividade física na vida diária de pacientes com DPOC?

OBJECTIVES: To study the relationship between the level of physical activity in daily life and disease severity assessed by the BODE index in patients with chronic obstructive pulmonary disease (COPD). METHODS: Sixty-seven patients with COPD (36 men) with forced expiratory volume in the first second (FEV1) of 39 (27-47) percent predicted and age of 66 (61-72) years old were evaluated by spirometry, dyspnea levels (measured by the Medical Research Council scale, MRC) and by the 6-minute walking test (6MWT). The BODE index was calculated based on the body mass index (weight/height²), FEV1, MRC and 6MWT, and then the patients were divided in four quartiles according to their scores (Quartile I: 0 to 2 points, n=15; Quartile II: 3 to 4 points, n=20; Quartile III: 5 to 6 points, n=23; Quartile IV: 7 to 10 points, n=9). Two activity monitors (DynaPort® and SenseWear®) were used to evaluate the level of physical activity in daily life. The Kruskal-Wallis test (Dunns's post-hoc test), the Mann-Whitney test and the Spearman Correlation Coefficient were used for statistical analysis. RESULTS: There were modest correlation between the BODE index and the time spent walking per day, the total daily energy expenditure and the time spent in moderate and vigorous activities per day (-0.32 < r <- 0.47; p<0.01 for all variables). When comparing the pooled quartiles I+II with III+IV, there were significant difference between the time spent walking per day, the total daily energy expenditure and the time spent in moderate activities per day (p<0.05). CONCLUSION: The level of physical activity in daily life has a modest correlation with the classification of COPD severity assessed by the BODE index, reflecting only differences between patients with classified as mild-moderate and severe-very severe COPD.

OBJETIVOS: Estudar a relação entre nível de atividade física na vida diária (AFVD) e gravidade da Doença Pulmonar Obstrutiva Crônica (DPOC) avaliada pelo índice BODE. MÉTODOS: Sessenta e sete pacientes com DPOC (36 homens), com volume expiratório forçado no primeiro segundo (VEF1) 39(27-47) por centoprevisto, e 66(61-72)anos foram submetidos a avaliações de espirometria, grau de dispneia (Medical Research Council scale, MRC) e teste de caminhada de 6 minutos (TC6). O índice BODE foi calculado com base no índice de massa corpórea (peso/estatura²), VEF1, MRC e TC6, e os pacientes foram subdivididos em quatro quartis de acordo com sua pontuação no BODE (quartil I: 0 a 2 pontos, n=15; quartil II: 3 a 4 pontos, n=20; quartil III: 5 a 6 pontos, n=23; quartil IV: 7 a 10 pontos, n=9). O nível de AFVD foi avaliado por dois monitores de atividade física (DynaPort® e SenseWear®). Os testes de Kruskal-Wallis (pós-teste Dunns), Mann-Whitney e Coeficiente de Correlação de Spearman foram utilizados na análise estatística. RESULTADOS: Houve correlação modesta entre os escores do índice BODE e o tempo gasto andando/dia, gasto energético total e tempo gasto/dia em atividades moderadas e vigorosas (-0,32< r <-0,47; p<0.01 para todos). Quando comparados os quartis agrupados I+II com III+IV, houve diferença significante entre o tempo gasto andando/dia, gasto energético total e tempo gasto em atividades moderadas (p<0,05). CONCLUSÃO: O nível de AFVD apresenta correlação modesta com a classificação da gravidade da DPOC dada pelo índice BODE, refletindo apenas diferenças entre pacientes com doença leve-moderada e grave-muito grave.