Proprioceptive changes impair balance control in individuals with chronic obstructive pulmonary disease

Copyright @ 2013 Janssens et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Introduction: Balance deficits are identified as important risk factors for falling in individuals with chronic obstructive pulmonary disease (COPD). However, the specific use of proprioception, which is of primary importance during balance control, has not been studied in individuals with COPD. The objective was to determine the specific proprioceptive control strategy during postural balance in individuals with COPD and healthy controls, and to assess whether this was related to inspiratory muscle weakness. Methods: Center of pressure displacement was determined in 20 individuals with COPD and 20 age/gender-matched controls during upright stance on an unstable support surface without vision. Ankle and back muscle vibration were applied to evaluate the relative contribution of different proprioceptive signals used in postural control. Results: Individuals with COPD showed an increased anterior-posterior body sway during upright stance (p=0.037). Compared to controls, individuals with COPD showed an increased posterior body sway during ankle muscle vibration (p=0.047), decreased anterior body sway during back muscle vibration (p=0.025), and increased posterior body sway during simultaneous ankle-muscle vibration (p=0.002). Individuals with COPD with the weakest inspiratory muscles showed the greatest reliance on ankle muscle input when compared to the stronger individuals with COPD (p=0.037). Conclusions: Individuals with COPD, especially those with inspiratory muscle weakness, increased their reliance on ankle muscle proprioceptive signals and decreased their reliance on back muscle proprioceptive signals during balance control, resulting in a decreased postural stability compared to healthy controls. These proprioceptive changes may be due to an impaired postural contribution of the inspiratory muscles to trunk stability. Further research is required to determine whether interventions such as proprioceptive training and inspiratory muscle training improve postural balance and reduce the fall risk in individuals with COPD.This work was supported by the Research Foundation – Flanders (FWO) grants 1.5.104.03, G.0674.09, G.0598.09N and G.0871.13N

Impaired Postural Control Reduces Sit-to-Stand-to-Sit Performance in Individuals with Chronic Obstructive Pulmonary Disease

Abstract Background: Functional activities, such as the sit-to-stand-to-sit (STSTS) task, are often impaired in individuals with chronic obstructive pulmonary disease (COPD). The STSTS task places a high demand on the postural control system, which has been shown to be impaired in individuals with COPD. It remains unknown whether postural control deficits contribute to the decreased STSTS performance in individuals with COPD. Methods: Center of pressure displacement was determined in 18 individuals with COPD and 18 age/gender-matched controls during five consecutive STSTS movements with vision occluded. The total duration, as well as the duration of each sit, sit-to-stand, stand and stand-to-sit phase was recorded. Results: Individuals with COPD needed significantly more time to perform five consecutive STSTS movements compared to healthy controls (1966 vs. 1364 seconds, respectively; p = 0.001). The COPD group exhibited a significantly longer stand phase (p = 0.028) and stand-to-sit phase (p = 0.001) compared to the control group. In contrast, the duration of the sit phase (p = 0.766) and sit-to-stand phase (p = 0.999) was not different between groups. Conclusions: Compared to healthy individuals, individuals with COPD needed significantly more time to complete those phases of the STSTS task that require the greatest postural control. These findings support the proposition that suboptimal postural control is an important contributor to the decreased STSTS performance in individuals with COPD

Respiratory rehabilitation after acute exacerbation of COPD may reduce risk for readmission and mortality – a systematic review

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (COPD) represent a major burden for patients and health care systems. Respiratory rehabilitation may improve prognosis in these patients by addressing relevant risk factors for exacerbations such as low exercise capacity. To study whether respiratory rehabilitation after acute exacerbation improves prognosis and health status compared to usual care, we quantified its effects using meta-analyses. METHODS: Systematic review of randomized controlled trials identified by searches in six electronic databases, contacts with experts, hand-searches of bibliographies of included studies and conference proceedings. We included randomized trials comparing the effect of respiratory rehabilitation and usual care on hospital admissions, health-related quality of life (HRQL), exercise capacity and mortality in COPD patients after acute exacerbation. Two reviewers independently selected relevant studies, extracted the data and evaluated the study quality. We pooled the results using fixed effects models where statistically significant heterogeneity (p < or = 0.1) was absent. RESULTS: We identified six trials including 230 patients. Respiratory rehabilitation reduced the risk for hospital admissions (pooled relative risk 0.26 [0.12-0.54]) and mortality (0.45 [0.22-0.91]). Weighted mean differences on the Chronic Respiratory Questionnaire were 1.37 (95% CI 1.13-1.61) for the fatigue domain, 1.36 (0.94-1.77) for emotional function and 1.88 (1.67-2.09) for mastery. Weighted mean differences for the St. Georges Respiratory Questionnaire total score, impacts and activities domains were -11.1 (95% CI -17.1 to -5.2), -17.1 (95% CI -23.6 to -10.7) and -9.9 (95% CI -18.0 to -1.7). In all trials, rehabilitation improved exercise capacity (64-215 meters in six-minute walk tests and weighted mean difference for shuttle walk test 81 meter, 95% CI 48-115). CONCLUSION: Evidence from six trials suggests that respiratory rehabilitation is effective in COPD patients after acute exacerbation. Larger trials, however, are needed to further investigate the role of respiratory rehabilitation after acute exacerbation and its potential to reduce costs caused by COPD

ACTIVATE: the effect of aclidinium/formoterol on hyperinflation, exercise capacity, and physical activity in patients with COPD

The Phase IV, 8-week, randomized, double-blind, placebo-controlled ACTIVATE study (NCT02424344) evaluated the effect of aclidinium/formoterol (AB/FF) 400/12 mug twice daily on lung hyperinflation, exercise capacity, and physical activity in patients with moderate-to-severe COPD. Patients received AB/FF (n=134) or placebo (n=133) (1:1) via the Genuair/Pressair(R) dry powder inhaler for 8 weeks. From Weeks 5 to 8, all patients participated in behavioral intervention (BI; daily messages providing step goals). The primary end point was trough functional residual capacity (FRC) at Week 4. Exercise endurance time and physical activity were assessed at Week 4 (pharmacotherapy only) and at Week 8 (8 weeks of pharmacotherapy plus 4 weeks of BI). Other end points included post-dose FRC, residual volume, and inspiratory capacity (IC) at rest and during exercise. After 4 weeks, trough FRC improved with AB/FF versus placebo but did not reach significance (125 mL; P=0.0690). However, post-dose FRC, residual volume, and IC at rest improved significantly with AB/FF at Week 4 versus placebo (all P<0.0001). AB/FF significantly improved exercise endurance time and IC at isotime versus placebo at Week 4 (P<0.01 and P<0.0001, respectively) and Week 8 (P<0.05 and P<0.0001, respectively). AB/FF achieved higher step counts (P<0.01) with fewer inactive patients (P<0.0001) at Week 4 versus placebo. Following BI, AB/FF maintained improvements in physical activity at Week 8 and nonsignificant improvements were observed with placebo. AB/FF 400/12 mug demonstrated improvements in lung hyperinflation, exercise capacity, and physical activity versus placebo that were maintained following the addition of BI. A 4-week period of BI might be too short to augment the improvements of physical activity observed with AB/FF

Respiratory rehabilitation after acute exacerbation of COPD may reduce risk for readmission and mortality – a systematic review

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (COPD) represent a major burden for patients and health care systems. Respiratory rehabilitation may improve prognosis in these patients by addressing relevant risk factors for exacerbations such as low exercise capacity. To study whether respiratory rehabilitation after acute exacerbation improves prognosis and health status compared to usual care, we quantified its effects using meta-analyses. METHODS: Systematic review of randomized controlled trials identified by searches in six electronic databases, contacts with experts, hand-searches of bibliographies of included studies and conference proceedings. We included randomized trials comparing the effect of respiratory rehabilitation and usual care on hospital admissions, health-related quality of life (HRQL), exercise capacity and mortality in COPD patients after acute exacerbation. Two reviewers independently selected relevant studies, extracted the data and evaluated the study quality. We pooled the results using fixed effects models where statistically significant heterogeneity (p ≤ 0.1) was absent. RESULTS: We identified six trials including 230 patients. Respiratory rehabilitation reduced the risk for hospital admissions (pooled relative risk 0.26 [0.12–0.54]) and mortality (0.45 [0.22–0.91]). Weighted mean differences on the Chronic Respiratory Questionnaire were 1.37 (95% CI 1.13–1.61) for the fatigue domain, 1.36 (0.94–1.77) for emotional function and 1.88 (1.67–2.09) for mastery. Weighted mean differences for the St. Georges Respiratory Questionnaire total score, impacts and activities domains were -11.1 (95% CI -17.1 to -5.2), -17.1 (95% CI -23.6 to -10.7) and -9.9 (95% CI -18.0 to -1.7). In all trials, rehabilitation improved exercise capacity (64–215 meters in six-minute walk tests and weighted mean difference for shuttle walk test 81 meter, 95% CI 48–115). CONCLUSION: Evidence from six trials suggests that respiratory rehabilitation is effective in COPD patients after acute exacerbation. Larger trials, however, are needed to further investigate the role of respiratory rehabilitation after acute exacerbation and its potential to reduce costs caused by COPD

The Belgian trial with azithromycin for acute COPD exacerbations requiring hospitalization: an investigator-initiated study protocol for a multicenter, randomized, double-blind, placebo-controlled trial

Background: Long-term use of macrolide antibiotics is effective to prevent exacerbations in chronic obstructive pulmonary disease (COPD). As risks and side effects of long-term intervention outweigh the benefits in the general COPD population, the optimal dose, duration of treatment, and target population are yet to be defined. Hospitalization for an acute exacerbation (AE) of COPD may offer a targeted risk group and an obvious risk period for studying macrolide interventions. Methods/design: Patients with COPD, hospitalized for an AE, who have a smoking history of > 10 pack-years and had > 1 exacerbation in the previous year will be enrolled in a multicenter, randomized, double-blind, placebo-controlled trial (NCT02135354). On top of a standardized treatment of systemic corticosteroids and antibiotics, subjects will be randomized to receive either azithromycin or placebo during 3 months, at an uploading dose of 500 mg once a day for 3 days, followed by a maintenance dose of 250 mg once every 2 days. The primary endpoint is the time-to-treatment failure during the treatment phase (ie, from the moment of randomization until the end of intervention). Treatment failure is a novel composite endpoint defined as either death, the admission to intensive care or the requirement of additional systemic steroids or new antibiotics for respiratory reasons, or the diagnosis of a new AE after discharge. Discussion: We investigate whether azithromycin initiated at the onset of a severe exacerbation, with a limited duration and at a low dose, might be effective and safe in the highest risk period during and immediately after the acute event. If proven effective and safe, this targeted approach may improve the treatment of severe AEs and redirect the preventive use of azithromycin in COPD to a temporary intervention in the subgroup with the highest unmet needs

Physical activity is increased by a 12 week semi-automated telecoaching program in patients with COPD, a multicenter randomized controlled trial

Rationale Reduced physical activity (PA) in patients with COPD is associated with a poor prognosis. Increasing PA is a key therapeutic target, but thus far few strategies have been found effective in this patient group. Objectives To investigate the effectiveness of a 12 week semi-automated telecoaching intervention on PA in COPD patients in a multicenter European RCT. Methods 343 patients from 6 centers, encompassing a widespectrum of disease severity, were randomly allocated to either a usual care group (UCG) or a telecoaching intervention group (IG) between June and December 2014. This 12 weeks intervention included an exercise booklet and a step counter providing feedback both directly and via a dedicated smartphone application. The latter provided an individualized daily activity goal (steps) revised weekly and text messages as well as allowing occasional telephone contacts with investigators. Physical activity was measured using accelerometry during 1 week preceding randomization and during week 12. Secondary outcomes included exercise capacity and health status. Analyses were based on modified intention-to-treat. Main results Both groups were comparable at baseline in terms of factors influencing PA. At 12 weeks, the intervention yielded a between group difference of mean, 95% CI [ll-ul] +1469, 95% CI [971 – 1965] steps.day-1 and +10.4, 95% CI [6.1 - 14.7] min.day-1 moderate physical activity; favoring the IG (all p≤0.001). The change in six minute walk distance was significantly different (13.4, 95% CI [3.40 - 23.5]m, p<0.01), favoring the IG. In IG patients an improvement could be observed in the functional state domain of the CCQ (p=0.03), when compared to UCG. Other health status outcomes did not differ. Conclusions The amount and intensity of PA can be significantly increased in COPD patients using a 12 week semi-automated telecoaching intervention including a step counter and an application installed on a smartphone. Trial registration NCT02158065 (clinicaltrials.gov

Determinants of physical activity in daily life in candidates for lung transplantation

Summary Background: Participation in daily physical activity (PA) has never been objectively assessed in candidates for lung transplantation (LTx). The main research questions were: 1) How active are LTx-candidates in daily life? 2) What are determinants of activity behavior before LTX? Methods: Ninety-six candidates for LTx (diagnosis of COPD or interstitial lung disease; mean age 55 AE 7 years) underwent measurements of PA, pulmonary function, 6-min walking distance (6MWD), muscle force and health-status (SF-36 scale). Results: Patients were markedly inactive (5% of waking hours walking, 26% standing and 69% sedentary). Backward multiple regression identified 6MWD (expressed as % of predicted value; b Z 73.0 steps, partial r 2 Z 0.36, p Z 0.00), a higher score on the energy/fatigue scale of the SF-36 (b Z 28.6 steps, partial r 2 Z 0.09, p Z 0.00) and a higher expiratory muscle force (expressed as % of predicted value; b Z 11.8 steps, partial r 2 Z 0.05, p Z 0.02) as determinants of daily steps. Minutes of mild to moderate (!2 METs) activity were determined by 6MWD (expressed as % of predicted value; b Z 2.14 min, partial r Conclusions: The 6MWD was the main determinant of an inactive lifestyle in these patients. Respiratory muscle force, energy and fatigue and seasonal variations explained some additional variability in activity behavior. Patients should be encouraged to participate in interventions aimed at improving physical fitness and participation in daily physical activity before LTx.